TW565621B - Cold-rolled steel sheet and galvanized steel sheet having strain age hardenability property and method for producing the same - Google Patents

Abstract

A cold rolled steel sheet and an alloyed hot dip galvanized steel sheet produced from the cold rolled sheet are provided, which are characterized in that it has a chemical composition, in mass %; C: 0.01% or less, Si: 0.005 to 1.0%, Mn: 0.01 to 1.0%, Nb: 0.005 to 0.050%, Al: 0.005 to 0.030%, N: 0.005 to 0.040%, B: 0.0005 to 0.0015%, P: 0.05% or less, S: 0.01% or less and balance: substantially Fe, with the proviso that the composition satisfies the following formulae (1) and (2): N% >= 0.0015+14/93.Nb%+14/27.Al%+14/11.B% ... (1); C% <= 12/93.Nb% ... (2); and exhibit a significantly enhanced tensile strength as subjected to press forming heat treatment, while maintaining excellent deep drawing properties in press forming.

Description

565621 A7 ____B7 V. Description of the invention (彳) [Technical Field] (Please read the precautions on the back before filling out this page) The present invention relates to the requirements for use as construction members, mechanical structural parts, and automotive structural parts. Structural strength, particularly where strength and / or rigidity during deformation are required, cold rolled steel sheets with excellent deformation age hardening properties of material steel plates of formed bodies that have been subjected to strength-up heat treatment after processing and forming such as stamping, Electroplated galvanized steel sheet, hot-dip galvanized steel sheet, and alloyed hot-dip galvanized steel sheet, and a method for manufacturing these steel sheets. In the present invention, "excellent aging hardening after deformation" means having / having the following characteristics: (1) After the pre-deformation of 5% of tensile deformation is performed, it is maintained at a temperature of 170 ° C for 20 When the aging treatment is performed under the condition of minutes, the increase in the deformation stress before and after the aging treatment (referred to as B Η; B Η = undulating stress after aging treatment-pre-deformation stress before aging treatment) exceeds '80 M pa; 2) And the tensile strength increase before and after the deformation aging treatment (the aforementioned pre-deformation + the aforementioned aging treatment) (referred to as △ TS; △ TS = tensile strength after aging treatment-tensile strength before pre-deformation) exceeds 40 M pa Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. [Background Art] When manufacturing a punched body of a thin steel plate, before the punching is performed, the thin steel plate is made soft so that it can be easily punched, and it is hardened after punching. The methods for improving the strength of parts include the method of painting and baking at a temperature of less than 200 ° C. As for the size of this coated paper, the Chinese National Standard (CNS) A4 specification (210 乂 297 mm) is applicable. )) &Quot; a-4-565621

For the installation of steel plates for baking, some people have developed the so-called fifth, description of the invention (2) Β Η steel plate printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. The method disclosed in the gazette is to add Nb according to the amount of C ′ N and A 1 in the steel, limit Nb / (solid solution c + solid solution n) to a specific range by at%, and control annealing after The method of adjusting the solid solution C and the solid solution N in the steel plate according to the cooling rate. In addition, Japanese Patent Publication No. 61-45689 discloses a method for improving baking hardening by adding T i and N b in combination. However, the above-mentioned steel sheet has excellent deep-drawing properties, and therefore has low strength when used as a material steel sheet, and may not be used as a structural material. Also, the method disclosed in Japanese Patent Application Laid-Open No. 5-25549 is borrowed A method of adding W, Ci, and Mo to steel to improve baking hardenability, alone or in combination. In the above-mentioned conventional technology, the reason for the strength increase due to baking hardening is due to the role of a small amount of solid solution C and solid solution N in the steel sheet, and as is well known, in the case of B Η steel sheet, only the It makes the material's undulating strength increase, but does not increase the tensile strength. Therefore, it only has the effect of increasing the stress at the beginning of the deformation of the part. As for the stress (tensile strength after molding) required for deformation in the entire deformation range from the beginning of the deformation to the end of the deformation, the lifting stress cannot be fully achieved. Effect. As for the cold-rolled steel sheet whose tensile strength will increase after forming, for example, this paper size applies the Chinese National Standard (CNS) Α4 specification (210 × 297 mm) ~ &quot; '(Please read the precautions on the back before filling (This page) · # 今 、 11

-5- 565621 A7 B7 V. Description of the invention (3): Japanese Patent Application Laid-Open No. 1 0-3 1 0 8 4 7 discloses the use of a heat treatment temperature range of 2 0 ~ 4 5 0 ° C, tensile strength Will rise, alloyed hot-dip galvanized steel sheet above 60 MPa. This steel sheet, based on mass%, contains C: 0.01 to 0.08%, Mn: 0.01 to 3.0%, and one or two or more of W, Cr, and Mo. The total content is 0.005 to 3.0%, and if necessary, Ti: 〇. 〇〇5〜0. 1%, Nb: 0.005 to 〇1%; V: / 〇 · 0 0 5 ~ 0 · 1% of one or two or more of these components, and the microscopic metallographic structure of steel is composed of ferrous iron or ferrous iron as the main body. However, this technology is based on Fine carbides are formed in the steel sheet by heat treatment. The deformation applied during stamping can effectively multiply the index and increase the amount of deformation. Therefore, it must be performed at a temperature of 2 0 to 37 ° The range of heat treatment requires a higher heat treatment temperature than the general baking hardening treatment temperature, which is a difficulty. In addition, due to current global environmental problems, restrictions on automobile exhaust emissions, the weight reduction of car bodies has become an extremely important issue. In order to reduce the weight of the car body and increase the strength of the steel plates used, it is very effective to use high-tensile steel plates to make steel plates with high tension and thinner plate thickness. Automotive parts that are made of high-tensile steel and thin plates are required to have various characteristics to match their functions. The required characteristics are different for different parts, for example, they are concave resistance, static strength against deflection, twist deformation, fatigue strength, and impact resistance. In other words, the application of this paper size applies to the Chinese National Standard (CNS) A4 specification (210X297 public director) (please read the precautions on the back before filling this page)

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs -6-565621 A7 B7 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the Invention (4) After the high-tensile steel sheet of automobile parts is processed, it must have such excellent characteristic. These characteristics are related to the strength of the steel sheet after the forming process. Therefore, in order to achieve the purpose of thinning, it is necessary to set a lower limit of the strength of the high-tensile steel sheet used. On the other hand, in the process of manufacturing automobile parts, steel plates are stamped and formed. If the strength of the steel sheet is too high, problems such as: (1) reduction in shape freezing properties and (2) cracking and necking during molding due to reduced ductility will occur after punching. In addition, after reducing the thickness of the plate, (3) the dent resistance (that is, the dent resistance against pits caused by local compressive load) will be deteriorated, which will hinder such problems. Increased use of high-tensile steel plates in automobile bodies. In order to solve this problem, one of the known methods is to use, for example, cold-rolled steel plates for exterior panels, for example, ultra-low carbon steel as a material, and use the final residual carbon content (C) in the solid solution state. Steel plate manufacturing technology controlled in the right range. This steel sheet is kept in a soft state during punching to ensure its shape freezing and ductility, and then caused by the coating and baking process of 170 ° CX 20 minutes after punching. The deformation and aging hardening phenomenon, and the improvement of the reduced stress is obtained, so as to ensure the concave resistance. This type of steel plate is solid-melted in steel to maintain softness during punching. Then, after punching and forming, the solid-state C is fixed in the punching process by painting and baking. It is introduced into the index during molding, which makes YS (Down Stress) rise. However, this steel sheet is based on the need to prevent surface defects, that is, knots (please read the precautions on the back before filling out this page) This paper size applies Chinese National Standard (CNS) A4 specification (210X 297 mm) 565621 A7 B7 Economy Printed by the Ministry of Intellectual Property Bureau's Consumer Cooperatives V. Invention Description (5) The viewpoint of the occurrence of structural strain must suppress the lowering of the yielding stress caused by deformation and age hardening. Therefore, in fact, the effect on the weight reduction of the parts is not great, which is one of the difficulties. In addition, for applications that are not very problematic in appearance, technical solutions have been proposed: steel plates that use solid solution N to increase the amount of baking hardening; the metallographic structure is made of ferrous iron and A composite structure made by Asada loose iron to further improve the hardenability of steel plates. For example, as disclosed in Japanese Patent Application Laid-Open No. 6 0-5 2 5 2 8 /, C: 0.02 to 0. 15%, Mn 0: 8 to 3 · 5%, and P: 〇 02 to 〇15%, Α1: less than 0 to 10%, N: ◦ 005 to 0, 025% of the steel is hot-rolled at a temperature below 55 ° C; and control is adopted The cooling heat treatment is a method for manufacturing a high-strength thin steel sheet having good ductility and spot welding characteristics as an annealing treatment after cold rolling. The steel sheet system manufactured by the technique disclosed in Japanese Patent Laid-Open No. 6 0-5 2 5 2 8 has a mixed structure composed of a low-temperature metamorphic product phase mainly composed of ferrous iron and Asada scattered iron, and It has excellent ductility, and actively uses the deformation and aging characteristics caused by the addition of nitrogen (N) at the time of painting and baking to achieve high strength. However, in the technique disclosed in Japanese Patent Laid-Open No. 6 0-5 2 5 2 8, although the increase in the yield stress YS caused by aging and deformation hardening is large, the increase in tensile strength TS is small. In addition, the increase in the drop stress YS changes greatly, and the mechanical characteristics change greatly, so there is also a problem that the thickness of the steel plate cannot be made to the current desired vapor (please read the precautions on the back before filling this page) ▼

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This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -8-565621 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economy A7 Of thinning. In addition, Japanese Patent Publication No. 5-24979 discloses that it contains C: 0.08 to 20%, Mn: 1.5 to 3.5%, and the rest is composed of Fe and inevitable impurities. The metallographic structure is a baking hardenable high-tensile cold-rolled steel sheet composed of uniform toughened iron containing less than 5% of ferrous grain iron or toughened iron containing local Asada loose iron. The cold-rolled steel sheet disclosed in Japanese Patent Publication No. 5-2 4 9 7 9 is rapidly cooled in a temperature range of 4 0 to 2 0 t / during the cooling process after continuous annealing, and then slow After cooling, a cold-rolled steel sheet having a high degree of baking hardening that has not been seen before with a metallographic structure mainly composed of toughened iron is produced. However, the steel sheet disclosed in Japanese Unexamined Patent Publication No. 5-2 4 9 7 9 after coating and baking can increase the yield strength and obtain an unprecedented high degree of baking hardening, but it cannot be combined with tensile strength. Lifting, therefore, if it is applied to parts requiring high strength, fatigue resistance and impact resistance after molding cannot be sufficiently improved. Therefore, there is still a problem that it cannot be applied to applications that strongly require high fatigue resistance and high impact resistance. In addition, Japanese Patent Publication No. 6 1-1 2 0 0 discloses a method for manufacturing a high-tensile steel sheet having a high I · 値. This manufacturing method is characterized by using extremely low-C steel as a material and After cold rolling, annealing is performed in a temperature range in which ferritic iron and Vostian iron coexist. Although the steel sheet obtained has high r 値 and high coating baking hardening property (BΗ), the amount of BΗ obtained is as high as 60 Μ Pa, and the steel sheet is also obtained after aging treatment. The drop point will also rise, but it does not have the paper size applicable to the Chinese National Standard (CNS) A4 specification (210X29? Mm) (Please read the precautions on the back before filling this page)

-9-565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the invention (7) The improvement of τ S, so the types of applicable parts still have their limits, which is their problem. In addition, although the strength of the above-mentioned conventional steel plate after coating and baking treatment measured by a simple tensile test is still good, it is necessary to make it deep-drawn as the actual forming conditions are different. There is still a large difference in strength required, and it cannot be said that it can be fully applied to parts required for high reliability applications. Among the hot-rolled steel sheets among the coated and baked steel sheets that are stamped into a body, for example: Japanese Patent Publication No. 8-2 3 0 4 8 discloses: when processed, it is kept soft, and after processing, A manufacturing method of a hot-rolled steel sheet by coating and baking treatment to improve tensile strength which can effectively improve fatigue resistance. This technology is to control the C content to 0.02 ~ 0.13% by mass, add the N content to a relatively large amount of 0.00080 ~ 〇2 0 50% by mass, and control the purification The rolling temperature and the coiling temperature are caused by a large amount of solid solution N remaining in the steel, and then the metal structure is made into a composite structure mainly composed of ferrous iron and Mata loose iron, and after forming, it is used A heat treatment temperature of 170 ° C to achieve an increase in tensile strength of more than 100 MPa. In addition, Japanese Unexamined Patent Publication No. 10-183301 discloses that the composition of steel, especially for C and N, is controlled to be C: 0. 01 to 0.12 mass%; N: 0. 00 〇1 ~ 0.01% by mass, and the average crystal grain size is controlled below 8 // m to ensure a high BH amount exceeding 8OMPa and at the same time the AI amount can be controlled below 4 5 MPa. Excellent baking hardenability (Please read the precautions on the back before filling this page)

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This paper size applies Chinese National Standard (CNS) A4 (210 X 297 mm) -10- 565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (8) and heat resistance to room temperature aging Rolled steel plate. However, these steel plates are all hot-rolled steel plates, so after refined rolling, the aggregate structure of ferrous iron becomes irregular due to the metamorphosis of Vostian iron / fertile iron, which makes it difficult to obtain high r 値. Is full. Deep drawing. Moreover, even if the hot-rolled steel sheet prepared by these technologies is used as a base material and cold rolling and recrystallization annealing treatment are performed again, it may not be possible to obtain the same "tensile strength improvement after forming-heat treatment." A high B Η amount exceeding / 8 Μ Pa ″. This is because the metallurgical structure of steel is affected by cold rolling and recrystallization annealing, and becomes a metallographic structure different from that during hot rolling. Moreover, when cold rolling is performed, a large cumulative deformation amount is generated, so it is easy to form. Carbides and nitrides cause the state of solid solution C and solid solution N to change. The present invention has been developed in view of the above-mentioned actual conditions, and an object of the present invention is to provide an excellent deep-drawing property can be maintained when punching, and then the tensile strength can be increased by punching-heat treatment. A cold-rolled steel sheet and an alloy-melt-galvanized steel sheet having excellent deformation age hardening properties, and a manufacturing method which can favorably manufacture these steel sheets. In addition, the present invention has been made in view of the problems of the above-mentioned conventional technology, and is intended to provide excellent deep-drawing properties of TSX r 72 7 5 Μ Pa or higher and excellent deformation age hardening properties (B Η 2 8 Ο The cold-rolled steel sheet for deep drawing and molten galvanized steel sheet (including alloyed molten galvanized steel sheet) of MPa and △ TS-4 OMP a or more), and a manufacturing method which can advantageously manufacture these steel sheets are purpose. (Please read the notes on the back before filling this page)

This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -11-565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (9) In addition, the present invention aims to solve the above-mentioned traditional technologies The problem is to provide: it is suitable for automotive parts that require a high degree of moldability, is soft, has high moldability and stable quality characteristics, and can be easily molded into complex shapes of automotive parts without springback, Twisted, reverse warped, and other bad shapes, cracks, etc., and after molding into automobile parts, heat treatment can be used to obtain sufficient strength required for automobile parts and have a sufficient contribution to the weight reduction of automobile bodies. 1 _ · A high-strength cold rolled steel sheet having a high r 値 of 2 or more, and excellent deformation age hardening properties; and a manufacturing method for manufacturing these steel sheets that can / industrially and inexpensively without distorting the shape. [Disclosure of the Invention] In order to solve the above-mentioned problems, the present inventors tried to change the composition and manufacturing conditions to manufacture a steel sheet and conducted many material evaluation experiments. As a result, a certain idea was found, that is, N (nitrogen) that has not been actively used in the field that requires high processability as a strengthening element, and effectively used this N as a strengthening element The large deformation and aging hardening phenomenon caused by the effect of the metal can easily have both the characteristics of improving moldability and high strength after molding. In addition, the present inventors also found a certain idea, that is, in order to effectively utilize the deformation age hardening phenomenon caused by the action of N (nitrogen), the deformation age hardening phenomenon caused by the action of N (nitrogen) must be combined with The coating and baking conditions of automobiles, or more actively combined with the heat treatment conditions after molding, therefore, by applying hot rolling conditions, cold rolling, and cold rolling annealed strips 1 paper standard to Zhongguanjiaxian (0 called / \ 4 胁 （21 () &gt; &297; 297mm) --- -12- (Please read the precautions on the back before filling this page)

565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Disclosure of Invention (1 ()) Correction can effectively control the microscopic structure (metallographic structure) and the amount of solid solution N of the steel plate to a certain range. In addition, it has also been found that, in order to allow the aging and hardening phenomenon caused by the action of N to stably occur, it is very important to control the nitrogen (N) content in terms of composition, especially in accordance with the aluminum (A1) content. In addition, the inventors also found a certain idea, that is, to reduce the C content in order to obtain high r 値, perform continuous annealing at a temperature in the dual-phase range of the ferrous iron-Vostian iron, and then control Its cooling rate makes the metallurgical structure become a metallurgical structure containing acicular fertile iron phase with an area ratio of more than 5% in the ferrous iron phase. Using this microscopic structure and a proper amount of solid solution N In combination, a cold-rolled steel sheet having excellent punchability and deformation age hardening properties with high r 値 can be obtained. In addition, the problem of room temperature aging deterioration that has been a problem in the past can be eliminated, and N can be fully utilized. ... That is, the present inventors have found that using nitrogen (N) as a strengthening element, and controlling the content of aluminum (A 1) as a key element in a proper range, and applying hot rolling conditions, cold rolling, and cold rolling annealing conditions By normalizing to optimize the microscopic structure and solid solution N, it is possible to obtain higher r 値 than conventional solid solution strengthened C-M η steel plates and crystallization strengthened steel plates (traditional steel plates). Steel sheet with excellent formability and deformation age hardening characteristics not seen in the conventional steel sheet described above. In addition, the steel sheet of the present invention is not only higher in strength after coating and baking treatment than that measured by a simple tensile test. In addition, the traditional steel plate is that when deep drawing is performed under actual stamping conditions, the deviation distribution in strength is small, and stable part strength characteristics can be obtained, which can be used in high requirements (please read the precautions on the back before (Fill in this page)

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This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -13- 565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (Reliable parts. For example: due to the large The amount of hardening in the part where the thickness of the plate becomes thinner than that in other parts is greater than that of other parts. If the result of evaluation with the load capacity of "sheet thickness X strength" is known, it is a result of uniformity, so In order to achieve the above-mentioned objective, the inventors have obtained the following ideas: (1) After forming and heat treatment, they want to improve the tensile strength. In order to perform tensile deformation, a new translocation must be introduced. The translocation that is introduced / introduced due to the molding interacts with intrusive elements or crystals, and even if the stress is reached, it is necessary to allow the Do not move the index that is introduced by pre-deformation. (2) It is desired to obtain the above by forming carbides, nitrides, or carbonitrides such as W, Cr, Mo, Ti, Nb, and Al. In order to reduce the heat treatment temperature after molding, the heat treatment temperature after molding must be increased to more than 200 ° C. Therefore, the active use of invasive elements or Fe carbide or Fe nitride will reduce the heat treatment temperature after molding. (3) Among the intrusive elements, compared with solid solution C, although solid solution N lowers the heat treatment temperature after molding, but it has a great interaction with the index introduced by molding, even if It has reached the upper descent stress, and it is not easy to move the index introduced during the pre-deformation. (4) Although the solid solution N in the steel exists in the crystal grains and the boundary of the crystal grains, the strength after the heat treatment after forming The increase amount is the increase amount of the larger area of the crystal particle boundary. Also (Please read the precautions on the back before filling this page) $

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This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -14-565621 A7 B7 V. Description of the invention (d That is, the smaller the crystal grain size is more favorable. (5) Based on the need to expand the boundaries of crystal particles From the viewpoint of the area, Nb and B are added in combination, and after the hot rolling is completed, the cooling is performed immediately. This suppresses the normal growth of iron crystal grains after the hot rolling and suppresses the post-cold rolling. The growth of crystal particles during recrystallization annealing is more advantageous. The present invention is based on the above-mentioned ideas, and the above-mentioned ideas are obtained based on the following experiments. / [Experiment 1] In terms of mass% conversion, : C: 0.0015%; B: 0.0010%; Si: 0.001%; Mn: 0.5%; P: 0.03%; S: 0.008% and; N: 0.011%; and Nb: 0.005 to 0.050% and A 1: 〇 〇〇5 to 0 · 0.30%; the rest is a sheet steel sheet (thickness ·· 30 mm) composed of Fe and inevitable hybrid components ) After heating uniformly at 1 1 0 0 ° C, the rolling temperature becomes 9 or more above the A 3 transformation point at the refined rolling temperature. Hot rolling was performed three times at 0 0 ° C, and after the rolling was completed, water cooling was performed immediately after 0.1 seconds. Then, heat treatment was performed on the steel strip coiling operation at 50 CTC for one hour. The obtained hot-rolled steel sheet having a thickness of 4 mm was cold-rolled at a rolling rate of 82.5%, and then recrystallized and annealed at 80 0 ° C for 40 seconds. · 8% rolling rate is used for quenched and tempered rolling. This paper size applies Chinese National Standard (CNS) A4 (210X297 mm) (please read the precautions on the back before filling this page), 11

Printed by the Employees ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs -15-565621 A7 B7 Printed by the Employees’ Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Tensile strength was measured by taking a test piece that complies with the JIS No. 5 standard and testing it at a deformation rate of 0 · 0 2 / sec using a general tensile tester. A tensile test piece conforming to the JIS No. 5 standard taken out in the rolling direction was given a tensile strain of 10%, and then subjected to a heat treatment of 1 2 Ot for 20 minutes, followed by a general tensile test. The tensile strength of these test pieces taken from the cold-rolled steel sheet and the test pieces subjected to a heat treatment at 120 ° C for another 20 minutes after giving a tensile deformation of 10%, were applied for 20 minutes. The difference in strength is regarded as the tensile strength increase after molding (△ TS). Figure 1 shows the steel composition (N% — 1 4/9 3 · Nb%-14/27 · Α1%-14 / 11 · Β%) and △ TS were investigated. The results shown in Figure 1 show that if the number (N% —14 / 93 · Nb% — 14/27 · Α1% — 14/11 · B%) is in the range of 0 · 〇〇1 5 mass%, △ TS becomes more than 6 OMP a. [Experiment 2] When converted by mass%, C: 0 · 0 0 1 ％; S i: 〇 · 〇 2%; Μ η · · 〇 6 % '' P: 〇.01%; S: 0.009%; N: 0.012%; A1: 0.〇1% and Nb: 〇.〇15%; and B: 0. 00005 ~ This paper size applies to China National Standard (CNS) A4 Specification (21 × 297 mm) (Please read the precautions on the back before filling this page) ▼ Order

-16- 565621 A7 B7 V. Description of the invention (u 〇 0 0 2 5%, the rest is the sheet steel sheet (thickness: 30 mm) composed of Fe and unavoidable composition. After being heated uniformly at 110 ° C, the hot rolling was performed three times in such a way that the refined rolling temperature became 9 2 0 ° C above the A 3 transformation point. After the rolling was completed, immediately after 0 · 1 second It was water-cooled. Then, a heat treatment equivalent to coiling work at 450 ° C for 1 hour was performed. The obtained sheet thickness: 4 mm of hot-rolled steel sheet was rolled at 8 2 _ 5% After cold rolling at a reduction rate, a recrystallization / annealing treatment at 8.0 ° C at 4.0 seconds is performed, and then temper rolling is performed at a rolling reduction rate of 0 to 8%. In the obtained cold-rolled steel sheet, a test piece conforming to the JIS No. 5 standard was taken along the rolling direction, and the tensile strength was measured by performing a test using a general tensile testing machine at a deformation rate of 0 · 02 / sec. In addition, the tensile test in accordance with JIS No. 5 taken from these cold-rolled steel sheets along the rolling direction The sheet was subjected to a tensile deformation of 10%, and then subjected to a heat treatment at 120 ° C for 20 minutes, and then subjected to a general tensile test. Fig. 2 is a graph showing the B content and △ The results of the investigation of the relationship between TS. From the results shown in Figure 1, it can be seen that when the B content is 0.0005 to 0.0015% by mass, the ATS becomes more than 60 MPa. It can be judged from the observation result of the structure that the high △ TS can be obtained because the crystal grains are made fine by adding N b and B in combination. That is, it can be deduced that when the B content is less than 0.005% by mass, this paper standard is applicable. China National Standard (CNS) A4 specification (210X29 * 7mm) (Please read the precautions on the back before filling out this page), 11 Printed by the Employee Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs-17- 565621 A7 B7 V. Description of the invention (In case of j, the effect of refining the crystal grains obtained by adding N b in combination is not great. On the contrary, when the B content exceeds 0.015% by mass, the boundaries of crystallized and recrystallized particles and their The amount of B nearby increases because this B atom is related to N A strong interaction between the sub, so reducing the effective amount of solid solution N, resulting in decreased ATS. [Experiment 3]

When converted in mass%, it will contain: C: 0.0010%; N /: 0.012%; B: 0.0010%; Si: 0.01%; Mn: 0.5%; P: 0.03%; S: 〇 0.08% and; Nb: 0.014% and A1: 0.01%; the remaining part is steel A with Fe and inevitable hybrid composition; and C: 〇.〇 10%; N: ◦0012%; B: 0.0001%; Si: 0.01%; Mn: 0.5%; P: 0.03%; S: 0.008%; and Nb: 0 _〇1 4% and A 1: 0 · 0 1%; the remaining part is Fe and the steel sheet (thickness: 30 mm) for each sheet of steel B with composition components unavoidably formed by 1 1 After heating at 50 ° C uniformly, three hot rollings are performed so that the refined rolling temperature becomes 9 1 0 ° C above the A: 3 abnormal point. After the rolling is completed, water cooling is performed immediately after 0 · 1 second. . Then, a heat treatment is performed which corresponds to a coil winding operation at 600 ° C for one hour. The obtained hot-rolled steel sheet having a thickness of 4 mm was cold-rolled at a rolling rate of 82.5%, and then recrystallized at 8 8 0 ° C for 40 seconds. The paper dimensions are in accordance with Chinese national standards ( CNS) A4 specification (210X297 mm) (Please read the precautions on the back before filling this page}-Order

Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs -18-565621 A7 B7 V. Description of the invention (d Annealing treatment, and then, quenched and tempered at a rolling rate of 0.8%. In the obtained cold-rolled steel sheet, a test piece conforming to the JIS No. 5 standard was taken along the rolling direction, and the tensile strength was measured by performing a test using a general tensile testing machine at a deformation rate of 0. 0 2 / sec. In addition, a tensile test piece conforming to the JIS No. 5 standard taken from these cold-rolled steel sheets along the rolling direction is given a tensile strain of 10% and subjected to a heat treatment at various temperatures for 20 minutes. Then, a general tensile test is performed. / Fig. 3 shows the results of investigation on the influence of heat treatment temperature after molding on △ TS. From the results shown in Fig. 3, if the heat treatment temperature after molding is In the lower temperature region below 200 ° C, steel A with extremely low carbon content and high nitrogen content has a higher △ TS than steel B, which has extremely low carbon content and low nitrogen content, But in high temperature areas It has the same degree of Δ TS. From the results of these experiments, it is known that if you want to ensure Δ TS in the low temperature region, it is effective to use solid solution N. In addition, Figure 4 shows the crystal grain size d. And steel composition (N% — 14/93 14/27 · Α 1% — 14/1 1 · Β%) for the reduction in the amount of stretching caused by the aging phenomenon at room temperature (ΔΕ 1) and the tensile strength after molding The result of investigation on the influence of the amount of rise (ATS). As for the evaluation method of the amount of decrease (△ E 1) in the amount of elongation, JIS No. 5 taken from the cold rolled steel sheet along the rolling direction was measured. The total tensile amount of the test piece specified in the standard; and the measurement of the other paper size to apply the Chinese National Standard (CNS) A4 specification (210 &gt; &lt; 297 mm) (Please read the precautions on the back before filling in this Page) Clothing · Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs-19- 565621 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 ____ V. Description of the invention 8 hours at room temperature in C state The difference between the two stretch amounts after the acceleration treatment of the treatment. As can be seen from Figure 4, when (N% — 1 4/9 3 · Nb% -14 / 27 * Al% -14 / ll · B%) When 値 exceeds 0 · 0 0 1 5 mass% and the crystal grain size d is less than 2 0 // m, it can have both high ATS and low ΔE1. [Experiment 4] When converted by mass%, Will contain: C: 0.0015%; Si: 0.30%; Mn: 0.8%; P: 0.03%; S: 0.005%; N: 0.002%; W &amp; Al: 〇. 02 ~ 0. 0 After 8% of the steel sheet for sheet metal is uniformly heated at 1 050 ° C, the hot rolling is performed seven times so that the refined rolling temperature becomes 6 7 0 ° C, followed by 7 0 0 X 5 hours of recrystallization annealing treatment. After the hot-rolled steel sheet having a thickness of 4 mm obtained was cold-rolled at a rolling rate of 8 2 · 5%, it was then subjected to 8 7 for 40 seconds. After recrystallization annealing at 5 ° C, quenched and tempered rolling was performed at a rolling reduction of 0.8%. From the cold-rolled steel sheet obtained in this way, a test piece conforming to the JIS No. 5 standard was taken along the rolling direction, and the test was performed using a general tensile tester at a deformation rate of 0. 0 0 3 / sec. In addition, TSX r 値 and Δ TS were measured. The results are shown in Table 5. It can be seen that when the conditions of N / A 1 ^ 0.30 are met, T S father 1: 27 50〇1 ^? 3, and / \ 丁 32401 ^? 3 can be achieved. This paper size applies Chinese National Standard (CNS) A4 specification (210X29 * 7mm) (Please read the precautions on the back before filling out this page) Order -20-565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Description of the invention (j and it has been additionally confirmed that when the conditions of N / A 1 ^ 〇 30 are met, the degree of B Η-8 Ο Μ Pa can be achieved. ， [Experiment 5] Conversion by mass% At the time, it will contain: C: 0.0015%; B: 0.0010%; Si: 0.01%; Mn: 0.5%; P: 0.03%; S: 0.000%; N: 0.011%; Nb: 0.00. 〇5 ～ 0_05%; and A1: / 〇05.05 ~ 0.03% of the steel sheet for sheet metal is heated uniformly at 1000t: so that the refined rolling temperature becomes 650 ° C. Hot rolling was performed seven times, followed by recrystallization annealing treatment of 800 × 60 seconds, and the obtained hot-rolled steel sheet having a thickness of 4 mm was cold-rolled at a rolling rate of 82.5%, and then Next, a recrystallization annealing process at 880 ° C for 40 seconds was performed, followed by temper rolling at a rolling rate of 0.8%. From the cold-rolled steel sheet obtained in this way, Rolling along the side A test piece conforming to the JIS No. 5 standard was used to test TSX r 値, B Η, and △ TS using a general tensile tester at a deformation rate of 0. 03 / sec. These measurements were compared with The relationship of N / (A 1 + Nb + B) is shown in Figure 5. In this experiment, a steel containing: Nb: 0.005 to 0.05% and Β ·· 0.00% was used. As shown in the figure, when N When the condition of / (A1 + Nb + B) g 0 · 3 0 is achieved, the degree to which β Η 2 80 MPa can be achieved; △ TSgeOMPa; and the degree of TSx r 値 ^ 85 0 MPa. This paper size applies Chinese National Standard (CNS) Α4 specification (210X297 mm) (Please read the precautions on the back before filling this page) ▼

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-21-565621 A7 B7 V. Description of the invention (j [Experiment 6], (Please read the precautions on the back before filling this page) When converting to mass%, it will include ·· C: 0. 0 0 1 0%;

Si: 0.02%; Mn: 0.6%; P: 0.01%; S: 0.09%; N: 0.015%; Nb: 0.015%; A1: 0.01%; Β: 0 · 0001 to 〇 · 0025% of the steel sheet for sheet metal is uniformly heated at 1050 ° C, and then hot rolled seven times so that the refined rolling temperature becomes 6 8 0 t, and then 7 5 Ο X 5 After recrystallization annealing for a batch of hours, the obtained sheet thickness: 4 mm of the hot-rolled steel sheet was cold-rolled at a rolling ratio of 8 2 · 5%, and then 8 8 0 for 40 seconds was performed. The recrystallization annealing treatment at ° C was followed by temper rolling at a roll reduction of 0.8%. From the cold-rolled steel sheet obtained in this way, a test piece conforming to the JIS No. 5 standard was taken along the rolling direction, and the test was performed using a general tensile tester at a deformation rate of 0.03 / sec. On the other hand, TSX r 値, BΗ, and Δ TS were measured. The relationship between these measured radon and B content is shown in Fig. 6. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs as shown in the figure, when the content of B is in the range of 0 · 0.0003 ~ 0 · 0015%, it can reach B Η 2 8 〇 Μ P a Not only that, but also a higher △ TS level, which is the degree of OMP a, when compared with the B content &lt; 0.0000%, and the degree of TS x r ^ 8 5 Μ Pa. In addition, it can be seen from the microscopic observation: in this range of B content, the crystal grains are particularly fine. ° From the results of experiments 5 and 6, it can be judged that ... In order to meet N / (This paper size applies to China National Standard (CNS) A4 Specification (21 × 297 mm) -22- 565621 Printed by A7 B7 of Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs V. Description of Invention (d Al + Nb + B)-0 · 3 0 When the B content is set to B · 0003%, the crystal grains can be made finer by adding Nb in a composite manner, and the level of △ TS, TSX 1: 1 can be further improved. When the B content &lt; 0 · At 0003%, even if N b is added in combination, it does not have the effect of making the crystal grains finer. It is speculated that this is because the amount of B crystallized at the border of crystal grains and its vicinity increases, because the The strong interaction leads to a reduction in the effective amount of solid solution N. In addition, the case where Nb was replaced by the addition of T i and V was also examined. After conducting the same review, it was confirmed that the case where Nb was obtained and added The same effect. The present invention is based on the above original ideas. The main features of the invention are as follows: The cold-rolled steel sheet with excellent deformation age hardening property of the first invention of the present invention is characterized by having: when converted to mass%, c: 0 · 1 5 % Or less; S i: 1.0% or less; M η: 2.0% or less; P: 0.1% or less; S: 0 · 〇1% or less; A1: 0.005 to 0.030%; N: 〇 · 〇 〇50 ~ 0.0400%; and N / A1 exceeds 0.30, N in solid solution state exceeds 0.0001.0%, and the rest are Fe and unavoidable impurities. The paper standards are applicable to Chinese national standards. (CNS &gt; A4 size (210X297mm) &quot; a-23- (Please read the precautions on the back before filling out this page})-Order

565621 A7 B7 V. Description of the invention (21) Composition of composition. (Please read the precautions on the back before filling in this page.) The cold-rolled steel sheet with excellent deformation age hardening property of the first invention of the present case is among the above-mentioned composition, and the following ranges are particularly preferred. In terms of mass% conversion, it includes: C: 0 · 0 1% or less;

Si: 0.005 to 1.0%; Μη: 0. 01 to 1.5%; P: 0.1% or less; / S ·· 0 · 0 1% or less; A 1: 0.05 to 5 · 〇 〇3 0%; N: 0.005 to 0.040%; and N / A1 exceeds 0.30 or more, N in solid solution state exceeds 0.000 10%, the rest is Fe and inevitable impurities The composition of the composition. In addition, the first invention of the present case can meet the following ranges in addition to the above components: When converted to mass%, printed by the Consumers ’Cooperative of Intellectual Property Bureau of the Ministry of Economics: B: 0 · 00〇1 ~ 0.0030 %; Nb: 0.05 ~ 0.050%, and within the range defined by the following formulas (1) and (2): N% 20 · 0015 + 14/93 · Νϋ% + ΐ4 / 2 7 · A 1 % + 1 4/1 1 · Β% .... (1) Formula; C% $ 0 · 5 · (1 2/9 3) · Ν b% ....... .... (2). This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) -24- 565621

V. Description of the invention (g) In addition to the above composition, the first invention of the present case includes one or two or more of Cu, Ni, and Mo as required, and a total of 1.0% or less is more preferable. In the first invention of the present case, the crystal grain size of the steel sheet is preferably less than 2 0 //. M. In addition, the first invention of the present case is performed in a low temperature region where the heat treatment temperature is 120 to 200 ° C. The amount of strength improvement after forming is preferably more than 60 MPa. / In addition, the first invention of the present invention may also include a galvanized layer, a hot-dip galvanized layer, and an alloy on the surface of the cold-rolled steel sheet. The method for manufacturing a cold-rolled steel sheet having excellent deformation age hardening properties according to the second invention of the present invention is characterized in that: when it is converted to mass%, it includes: C: 〇. 0 1 % the following;

Si: 0.005 to 1.0%; Μπ: 〇.〇1 to 1.5%; P: 0. 1% or less; S: 0.001 or less; Α1: 0 · 〇05 to 0.03%; Ν: 〇.0 05 ～ 0 · 040%; and N / Α 1 exceeds 0 _ 3 or more, and the remaining part is essentially a steel sheet of Fe composition, which is hot rolled, and after finishing light rolling, cooling is started immediately, and Take in at a winding temperature of 4 0 ~ 80 0 ° C (read the precautions on the back before filling this page)

Printed by the Employees 'Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 Α7 Β7 Printed by the Consumers' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Then, recrystallization annealing treatment is performed at a temperature of 6500 ~ 900 ° C. In addition, in addition to the above-mentioned composition, the second invention of the present case can more preferably satisfy the following range: When converted into mass%, B: 0.0 0 01-0.0 0 30 ^: Nb: 〇〇〇〇5 ~ 0.050%, and in the range defined by the following formulas (1), (2): / .0015 + 14/93 * Nb% + 14/2 7 · A 1% + 1 4/1 1 · B% ...... (1) Formula; C% $ 〇 · 5 · (12/93) · N b% ............ (2) Formula. In the first invention of the present invention, during the temperature increasing process of the recrystallization annealing treatment, from 500 ° C. to the recrystallization temperature. Within the temperature range, the temperature is preferably increased at a rate of 1 to 20 ° C / sec. In addition, the second invention of the present case may be followed by a hot-dip galvanizing treatment after the recrystallization annealing treatment. Heat alloying treatment. The invention relates to a cold-rolled steel sheet for deep-drawing with excellent deformation age hardening properties, which has the following characteristics: when converted to mass%, it includes: c: 0 · 0 1% or less; s 1: 1 · 0% or less; Μη: 〇 · 〇1 ~ 1.5%; Ρ: 0 _ 1% or less; (Please read the precautions on the back before filling this page)

The size of this paper is applicable to China National Standard (CNS) A4 specification (210 × 297 mm) -26- 565621 Α7 Β7 ___ ^ 5. Description of the invention (S: 0.01% or less; A 1 ·· 0 · 0 0 5 ～ 〇_ 〇2 0%; 'N: 0.005 ~ 0.040%; and N / A1 exceeds 0.30 or more. N in the solid state exceeds 〇. 0 0 1 0%, the rest is F e and cannot be The composition composed of the impurities to be avoided, and T Sx r 値 is more than 750 MP a or more. In addition, the third invention of the present case, in addition to the above composition, contains: / When converted by mass%, Β: 0 · 0001 ~ 0.0〇30%; Nb: 0.005 ~ 0.050%, and it is preferably within the range defined by the following formulas (1) and (2): N% ^ 〇. 0015 + 14/93 * Nb% + 14/2 7 · A 1% + 1 4/1 1 · B% (1) Formula; C% S 〇 · 5 · (1 2/9 3) · N b% ... ......... (2). Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs, please read the notes on the back before filling out this page.) Also, the third invention in this case is based on the above composition In addition, it contains: B: 〇 · 〇〇〇〇1 ～ 〇 0030%; Nb: 0.005 to 0.050%;

Ti: 0.005 ~ 0.070%; ν ·· 〇 · 005 ~ 0.10% ·, one or more of which, this paper size is applicable to China National Standard (CNS) 84 (210X297 mm) -27- 565621 A7 B7 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs V. Invention Description (and 1 ^ / (八 1+ 汉 乜 + 丁 1 +++: 6) exceeds 0.30, (N in solution state exceeds 0.0 10% or more is preferred. The fourth invention of the present invention is a method for manufacturing a deep-drawn cold-rolled steel sheet having excellent deformation age hardening properties, which is characterized in that: when converted in mass%, it includes: c : 〇 · 0 1% or less; si: 0.0 〇5 ~ 1.0%; / Μη: 〇〇〇〇〇〇〜〇 · 〇%; P: 〇0.1% or less; s: 〇.〇i% or less ; A1: 0.005 to 0.030%; N: 0.005 to 0.04 0%; B: 0.00000 to 0.0030%; Nb: 0.005 to 0.050%; Ti: 0.005 to 0.070%; V : 〇.〇〇5 ~ 0.10%; one or two or more of them, and N / (A1 + Nb + Ti + V + B) more than 0.30 composition of steel materials, heated to more than 9 5 After 0 ° C, set the temperature at the end of rough rolling to less than 1 0 Rough rolling is performed in a temperature range of 0 0 ° C and higher than A r 3, and then, in a temperature range lower than A 3 and higher than 600 ° C, refined rolling is performed while applying lubrication , And take-up, from the beginning of the rough rolling to the end of the finishing rolling rolling (please read the precautions on the back before filling this page). 11

This paper size applies to Chinese National Standard (CNS) A4 specification (210X297 mm) -28- 565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of invention (y rate is set to exceed .80%, The obtained hot-rolled steel sheet is subjected to recrystallization annealing treatment, followed by cold rolling at a rolling ratio of 60 to 95%, and the obtained cold-rolled steel sheet is subjected to recrystallization annealing treatment. A cold-rolled steel sheet having excellent formability, deformation age hardening, and room temperature aging resistance is characterized by having: In terms of mass% conversion, it includes: C: 〇〇〇〇15 ~ 0.025%; S i: 1 · 0% or less; / Μ η: 2.0% or less; P: 0.1% or less; S: 0.02% or less; A 1: 0.02% or less; Ν: 0 · 〇05〇 ~ 0 〇25〇 ％; and containing: Β: 0.005 to 0.0050%; Nb: 0.002 to 0.050%; one or more of the two, and N / A 1 exceeds 0.30, solid N in the molten state is more than 0. 0 0 1 0%, and the rest is composed of Fe and unavoidable impurities, and has: Metallurgical structure composed of acicular ferrous phase with an iron content of more than 5% and a ferrous phase with an average crystal grain size of less than 20 # m; and its r 値 system exceeds 1 · 2. This paper scale is applicable to China Standard (CNS) A4 specifications (210 &gt; &lt; 297 mm) (Please read the precautions on the back before filling this page).

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-29- 565621 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 _________ B7____ V. Invention Description (2) In addition, the fifth invention in this case, in addition to the above components, when converted by mass%, includes the following One or two or more of the a group to the c group, the a group: one or two or more of Cu, Ni, Cr, and Mo, totaling less than 1.0%; the b group: T i, V One or two or more of them, a total of less than 0.1%; c group: one or two of Ca and REM, a total of 0_0010 to 0.010% is preferred. The sixth method of the present invention is a method for manufacturing a cold-rolled steel sheet having an excellent formability, deformation age hardening, and room temperature age resistance with r 値 exceeding 1.2 or more, which is characterized by: Including = C: 〇〇〇〇15 ～ 〇_〇25%; S i: 1 · 〇% or less; M η: 2 _ 0% or less; P: 0.1% or less; S: 〇.〇2 % Or less; A 1: 〇. 〇2% or less; Ν: 0 · 0050 to 0.0250%; and containing: B: 0.0003 to 0.0050%; Nb: 0.002 to 0.05%; one of the two or Two or more, (Please read the notes on the back before filling this page)

This paper size applies to China National Standard (CNS) A4 specifications (210 x 297 mm) -30-565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economy The above steel slab is heated until the heating temperature of the steel slab is higher than 1000 ° C or more, and rough rolling is performed to make a steel sheet for a thin plate. The steel sheet for the thin plate is sequentially implemented. Refined rolling where the temperature on the exit side of the refined roll exceeds 800 ° C; and a hot rolling process of coiling to a hot-rolled steel sheet at a coiling temperature lower than 65 ° C; and / Cold rolling of a rolled steel sheet by pickling and cold rolling to make a cold rolled steel sheet; and performing continuous annealing treatment on the cold rolled steel sheet within a temperature range in which the dual phase of the ferrous iron / Vostian iron coexists; and : The annealing process of the cold-rolled steel sheet that is cooled to a temperature range below 500 ° C at a cooling rate of 10 to 300 ° c / sec. The sixth invention of the present case is in addition to the above composition When converted into mass%, it also contains one of the following a group ~ c group Or two or more ya groups: one or two or more of Cu, Ni, Cr, Mo, totaling less than 1.0%; b group: one or two or more of T i, V, totaling 〇 .1% or less; c group: one or two of Ca and REM in total, preferably 0.000% to 0.010%. The seventh invention of the present invention has high r 値 and excellent deformation aging hardness ( (Please read the precautions on the back before filling out this page)

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This paper size applies to China National Standard (CNS) A4 (210X297 mm) -31-Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 B7 V. Description of the invention It has the following characteristics: In terms of mass% conversion, it includes:, C: 0.0025 to 0.15%; S 1: 1 · 0% or less; Μ η: 2 · 〇% or less; P · · 0 _ 0 8% The following; S: 0 · 0 2% or less; A 1 · · 〇 · 〇 2% or less; / N: 0.0050 ~ 0.0250%; and N / A 1 exceeds 0.3 or more, and the solid state N exceeds 0. Above 0 0 1 0%, the rest is composed of Fe and unavoidable impurities, and has a ferrite phase containing an average crystal grain size of less than 1 0 // m with an area ratio of more than 80% And the metallographic structure of the Asada loose iron phase which has an area ratio of more than 2% as the second phase; and its r 値 system exceeds 1.2 or more. Moreover, the seventh invention of the present case is in addition to the above composition. In mass% conversion, it also includes one or more of the following d groups to g groups, and the d group: Cu One or two or more of Ni, Cr, Mo, totaling less than 1.0%; e group: one or two or more of Nb, Ti, V, totaling less than 0.1%; f group Department: B ·· 〇〇〇〇3 0% or less; This paper size applies to the Chinese National Standard (CNS) A4 specification (210X297 mm) (Please read the precautions on the back before filling in this page}

-32- 565621 A7 ______ B7

V. Description of the invention (3 (J g lineage: one or two of Ca and RE M total 0.000 ~ 0.010% is preferred.) The eighth invention of the present case has r 値 exceeding 1 · A method for manufacturing a high-tension cold-rolled steel sheet with a high r 値 of 2 or more and excellent deformation age hardening properties and non-aging properties at room temperature is characterized in that: In terms of mass% conversion, it includes: C: 0.0025 to 0.15 %; S i: 1.0% or less;, M η: 2.0% or less; P: 0.08% or less; S: 0 · 02% or less; A 1 · · 0.02% or less; Ν: 0 · 〇〇〇〇〇〇0.0250%; and N / A 1 above 0.30% of the steel slab is heated until the heating temperature of the steel slab is higher than 1000t: above, and implemented Rough rolling is used to make steel sheets for thin plates. The steel sheets for thin plates are implemented in sequence: Refined rolls printed on the exit side of refined rolls by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, which have a temperature of more than 80 ° C. ; And a hot rolling process in which coiling is performed at a coiling temperature lower than 65 ° C to make a hot-rolled steel sheet; and pickling is performed on the hot-rolled steel sheet to Cold rolling to make a cold-rolled steel sheet; and for the cold-rolled steel sheet above the recrystallization temperature and below 800 ° C, the Chinese National Standard (CNS) M specification (21 °) is applied at this paper scale. &gt; &lt; 297 mm) -33-565621 A7 B7 printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs V. Implementation of box annealing within the annealing temperature range under the description of the invention (31); and, Continuous annealing is performed at an annealing temperature of A ci abnormal point ~ (A c 3 abnormal point-20 ° C,); and then, cooling is performed at a cooling rate of 10 to 300 ° C / sec until it is lower than Annealing process of cold-rolled steel sheet up to a temperature range of 500 ° C. The eighth invention of the present invention is implemented after the continuous annealing treatment described above, and is performed at a temperature lower than the cooling stop temperature of the cooling treatment and higher than 3 50 The overageing treatment that stays for more than 20 seconds in the temperature range of ° C is better. In addition, the eighth invention of the present invention includes the following d in addition to the above composition components when converted by mass%. Group ~ one or more of the g group, d group One, two or more of Cu, Ni, Cr, and Mo, totaling less than 1.0%; e group: one or two or more of Mb, Ti, and V, totaling less than 0.1%; f group Department: B: 0 · 0030% or less; g group: one or two of C a and REM is preferably 0. 0010 ~ 0.010% in total. [The best form for implementing the invention] First The reason for limiting the composition of the steel sheet to the aforementioned range in the first invention of the present case will be explained. (:: 0.01% by mass or less This paper size is applicable to Chinese National Standard (CNS) A4 (210X297mm)) (Please read the precautions on the back before filling this page)

-34-A7 565621 B7 V. Description of the invention (3) · (诮 Read the back and v notes before writing this page) The lower the C content, the better the deep drawing properties of the steel plate, and the better the forming properties As favorable. In addition, during the annealing process after cold rolling, N b and C are remelted to increase the amount of solid solution C in the crystal grains, which tends to cause a reduction in the aging resistance at room temperature. Therefore, the content of c is preferably suppressed to less than 0.01% by mass. It is more preferably less than 0.0005 mass%; more preferably less than 0.030 mass%.

Si: 0.005 to 1.0% by mass. Si is a useful ingredient for suppressing the decrease in the amount of stretch and is used to increase the strength. However, if the content is less than 0 · 0 0 55% by mass, the effect obtained by addition is not great. On the one hand, if it exceeds 1.0% by mass, the surface properties and state will be deteriorated and the ductility will be reduced. Therefore, S i is limited to the range of 0.005 to 1.0% by mass. A range of 0.01 to 0.75 mass% is more preferable. Μη: 0 · 01 to 1.5% by mass. Mn printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs can not only be used as a reinforcing component of steel, but also form MnS, which can suppress the embrittlement caused by S. If the amount of η is less than 0.01% by mass, the effect of adding Mn is not obvious. On the other hand, if the amount of η is more than 1.5% by mass, the surface properties and state will be deteriorated and the ductility will be reduced. Therefore, η is limited to 0 · 0 1 to 1.5% by mass. A range of 0.1 to 0.75% by mass is more preferable. P: 0.10% by mass or less. P can be used as a solid-solution strengthening component to effectively strengthen steel. However, if the added amount exceeds 0.10% by mass, (F e N b) X Ρ etc. will be formed. Phosphide, thereby reducing deep drawability. Therefore, this paper size applies to China National Standard (CNS) A4 (210X297 mm) -35- 565621 A7 B7 V. Description of the invention (g Limits P to 0 · 10% by mass. S: 0_0l% by mass (Please read the precautions on the back before filling this page) If the content of S is too much, it will increase the amount of intermediaries and reduce the ductility. Therefore, it is best to try to avoid the incorporation of S, but it can be allowed to 0.. 0 1% by mass. A1: 0.050 ~ 0.030% by mass. A 1 series can be added as a deoxidizer or to increase the yield of carbonitride-forming components, but if the content is less than 0.005 mass% / If sufficient effects are not obtained, on the other hand, if it exceeds 0.030% by mass, the amount of N that should be added to the steel is greatly increased, and therefore defects in the steel billet are likely to occur during steel making. Therefore The amount of A 1 is set in the range of 0.005 to 0.030% by mass. 〇: 0: 005 to 0.040% by mass. The Intellectual Property Bureau, Ministry of Economic Affairs, Employee Consumer Cooperatives, India, N, etc., can be used in the present invention. When the steel plate is deformed It is an important element of the function of effective hardening. However, if the content is less than 0.005% by mass, sufficient age hardening of deformation cannot be obtained. On the other hand, if it exceeds 0. 0 4 0% by mass, stamping will be reduced. Moldability. Therefore, the N content is set to a range of 0.005 to 0.040% by mass. A range of 0.08 to 0.015% by mass is more preferable. Β: 〇 0 001 to 0 · 003% by mass Β is Addition with N b can effectively refine the hot-rolled metallographic structure and cold-rolled recrystallized metallographic structure, and also has the effect of improving the secondary processing brittleness resistance. However, if the content is less than 0 · 0 0 0 1 Quality This paper size applies to China National Standard (CNS) A4 (210X297 mm) -36- 565621 A7 B7

V. Description of the invention (J (please read the precautions on the back before filling this page)%, it will not be able to obtain sufficient miniaturization effect. On the other hand, if it exceeds 0 _ 0 0 3 mass%, it will not only increase BN The amount of crystallization will also hinder the melting of the steel billet in the heating stage. Therefore, the B content is set to a range of 0.000001 to 0.003 mass%. 0 to 0 001 to 0. 0015 mass% The range is more preferable, and the range of 0. 0007 to 0. 0012 mass% is more preferable.

Nb: 0.005 to 0.050% by mass. If Nb is added together with B, it can effectively refine the hot-rolled metallographic structure / texture and cold-rolled recrystallized metallographic structure. Fixed to the role of N b C. In addition, Nb can form NbN nitrides, which is very helpful for the refinement of the cold-rolled recrystallized metallographic structure. However, if the content of Nb is less than 0.5 mass%, it will not only be difficult to crystallize and solidify solid solution C, but also the effect of miniaturizing the hot-rolled metallographic structure and cold-rolled recrystallized metallographic structure will be insufficient. On the other hand, if it exceeds 0.05 mass%, the ductility will decrease. Therefore, the Nb content is set to a range of 0.005 to 0. 050 mass%. A range of from 0.010 to 0.30% by mass is more preferable. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. As mentioned above, Nb has the function of fixing solid C into NbC and fixing it. Moreover, Nb N nitride can be formed. Similarly, A 1 N and B N may be formed separately from A 1 and B. Therefore, in order to sufficiently secure the amount of solid solution N and sufficiently reduce the amount of solid solution C, it is important to satisfy the relationship of the following formula (1) (2). · 0015 + 14/93 · Νΐ)% + 14/2 7 · A 1% + 1 4/1 1 · Β% ............ (1); This paper size applies to China National Standards (CNS) A4 specification (210X297 mm) -37- 565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs ^ V. Description of the invention (g C% $ 0 · 5 · (1 2/9 3) · N b% ............ (2) Formula, In addition, in order to obtain high deformation age hardenability and prevent age deterioration in the present invention, it is preferable to reduce the crystal grain size. That is, as disclosed in the aforementioned FIG. 4, by forming the crystal grain size d to be less than 2 0 // m, even if (N% — 1 4/9 3 · Nb% -14 / 27 ^ A1% -14/1 1 · B%) ^ 0 · 0 0 1 5 mass%, that is, when a large amount of solid N is contained, △ Ε 1 can be suppressed to less than 2 · 0%. Also, It is more preferable if the crystal grain size d is smaller than 1 5 # m. This is because, as shown in FIG. 4, if the crystal grain size d is smaller than 1 5 // m, △ E 1 The reason is that it is controlled to less than 1.5%. Next, the manufacturing conditions of the second invention of the present invention will be described. The steel with the best composition is melted by a conventional melting method such as a converter, and is formed into a steel sheet by a block making method or a continuous casting method. Next, after this steel sheet is uniformly heated, hot rolling is performed to produce hot rolling. Steel plate. Although the heating temperature for hot rolling is not specified in the present invention, in order to improve the deep drawing property, it is advantageous to fix the solid solution C in advance to crystallize carbides. Therefore, the heating of hot rolling The temperature is preferably set below 130 CTC. In order to further improve the processability, it is appropriate to set the heating temperature below 1 150 ° C. However, if the heating temperature is less than 900 ° C, The improvement of workability has become saturated, but it will increase the rolling load during hot rolling and increase the risk of problems during rolling. Therefore, the lower limit of the heating temperature is set to 900. This paper standard is applicable to China. Standard (CNS) A4 size (210X297 mm) (Please read the precautions on the back before filling in this page)

-38- 565621 A7 ___B7 V. Description of the invention (-t is appropriate. (Please read the notes on the back before filling out this page) Secondly, it is advisable to set the overall rolling rate during hot rolling above 70%. The reason is that if the overall rolling ratio is less than 70%, the crystallization of the hot-rolled steel sheet will not be sufficiently refined. In addition, the refined rolling during the hot-rolling process is performed at 9 6 to 6 50 °. The temperature range of C is preferably terminated, and the refining rolling temperature in hot rolling may be an r range above the A 3 transformation point or a cold region below the AI * 3 transformation point. The refining rolling temperature in the hot rolling If the temperature exceeds 9 6 CTC, the crystal grains of the hot-rolled steel sheet become coarse, and the deep drawability after cold rolling and annealing will deteriorate. On the other hand, if the temperature is less than 6 50 ° C, the deformation resistance will increase. Therefore, it will increase the hot rolling load and cause difficult rolling. After the finishing rolling in the above hot rolling process, it is best to start cooling immediately to prevent normal grain growth and to suppress the A in the cooling process. Crystallization of 1 N. Consumer Cooperatives of Intellectual Property Bureau, Ministry of Economic Affairs Printed here, although the conditions for the above-mentioned cooling treatment are not particularly limited, the cooling start time is preferably within 1.5 seconds after the finishing rolling is completed, and preferably within 1.0 seconds, It is best within 0.5 seconds. The reason is that if it is cooled immediately after rolling, the degree of supercooling in the deformed state will increase, so more iron cores will be produced, which will promote the growth of fat. Iron deforms, and can suppress the diffusion of solid solution N in the ferrite grains in the r phase, and can increase the amount of solid solution N existing in the ferrite grain grain boundary. As for the cooling rate, in order to ensure the solid solution N, the most It is better to exceed 10 ° C / sec. In addition, especially when the finishing rolling temperature of the hot rolling process exceeds A r 3, the paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) -39- 565621 A7 B7 V. Description of the invention (When the temperature is above the _ state point, based on the consideration of ensuring the solid solution N, it is best to set the cooling rate to more than 5 0 ° C / sec.. Next, the hot-rolled steel sheet is coiled into a steel strip. Coil. Although the coiling temperature at this time is higher, for carbonization The coarsening is more favorable, but if it exceeds 800 ° C, the scale formed on the surface of the hot-rolled steel sheet becomes thicker, which not only increases the burden of removing the scale, but also causes the steel strip to form nitrides. The amount of solid solution N varies in the length direction of the coil. On the other hand, if the coiling temperature is less than 4 0.0 ° C, the coiling operation will become difficult / difficult. Therefore, the coiling temperature of the hot-rolled steel sheet must be set to The range is from 8 0 to 4 0 ° C. Next, although cold rolling is performed on the hot-rolled steel sheet, the rolling rate of the cold rolling at this time must be set between 60 and 95%. The reason is that if the rolling rate of the cold rolling is less than 60%, a high r 値 cannot be achieved. On the other hand, if it exceeds 90%, r 値 will decrease instead. The cold-rolled steel sheet after the above-mentioned cold-rolling is then subjected to a recrystallization annealing treatment. Although the annealing method can use continuous annealing or batch annealing, continuous annealing is still more advantageous. In addition, this continuous annealing can use the processing method of the general continuous annealing processing line, or the processing method of the continuous molten galvanizing line. In addition, the annealing treatment is preferably performed at a temperature of 650 ° C or higher, and is preferably performed for 5 seconds or longer. The reason is that if the annealing temperature is less than 650 ° C, and the annealing conditions are less than 5 seconds, recrystallization cannot be completed, so low drawability will be caused. In order to further improve the deep drawability, it is better to apply the Chinese National Standard (CNS) A4 size (210X297 mm) to the paper size above 800 t (please read the precautions on the back before filling this page) Order

Yinzi-40- 565621 A7 B7, Consumer Cooperative of Employees of Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention In addition, the use of the higher temperature a + r dual-phase temperature range annealing process can change a part from α to r and develop the collective structure of 丨 1 1 1 丨 to increase r 値, but if α If it is completely deformed into r, the aggregate structure becomes irregular, which will reduce r 値 and damage the deep drawability. In addition, the upper limit of the annealing temperature is preferably 90 ° C. The reason is that if the annealing temperature exceeds At 9 0 ° C, the carbide will re-melt and increase the solid solution C excessively, so it will reduce the age and hardenability of the deformation. In addition, if an α-r abnormality occurs, the aggregate structure will change. If it is irregular, it will reduce r 値 and damage the deep drawability. In addition, during the temperature rise process in the recrystallization annealing described above, the temperature range from 500 ° C to the recrystallization temperature is slow. Heating by sufficiently crystallizing A 1 N Precipitation can effectively refine the crystal grain size of the steel sheet. Here, the temperature range in which the above-mentioned controlled heating should be performed is from 500 ° C starting from A 1 N and the like to the recrystallization temperature. The Consumer Cooperatives Association of the Intellectual Property Bureau of the Ministry of Economic Affairs ^ Also, the heating rate should be set in the range of 1 ~ 20 ° C / sec. The reason is that if the heating rate exceeds 20 ° C / sec, it cannot be obtained. On the other hand, if the amount of crystallization is less than 1 t / sec, the crystallization will become coarse and the effect of suppressing the growth of crystal grains will be worsened. In addition, after the recrystallization annealing described above, in order to further improve Shape correction, adjustment, and surface roughness, and tempering rolling with a rolling reduction rate of less than 10% can also be implemented. In addition, the cooling rate after uniform heating during recrystallization annealing is set on this paper scale to apply Chinese national standards (CNS) A4 specifications (210 X297 mm) -41-565621 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 __ _ B7_ V. Description of the invention (d is preferably 10 to 50 ° C. The reason for this Yes: Cooling speed is lower than When the temperature is lower than 10 ° c / sec, the crystal grains will grow during cooling and coarsening of the crystal grains will reduce the aging hardenability and the aging characteristics at room temperature. On the other hand, if it exceeds 50 ° C / If it is more than 2 seconds, the degree of diffusion of N in the solid state to the boundaries of the crystal grains is insufficient, and the aging characteristics at room temperature will be reduced. It is preferably 10 to 30 ° C / second. After the recrystallization annealing described above, In accordance with the necessity, the hot-dip galvanizing treatment can be performed first, and then the alloyed hot-dip galvanizing steel plate can be produced by heating and alloying treatment. The hot-dip galvanizing treatment and alloying treatment are not particularly limited, as long as they follow the traditional practice The known method is sufficient. In addition, after the production of the alloyed hot-dip galvanized steel sheet, the steel sheet is subjected to quenched and tempered rolling (over-low temperature refined steel sheet, polished refined steel sheet, and specific Steel plate with a rough texture); a surface-treated steel plate generally used as a thin steel plate, such as a steel plate having an oil film layer on the surface such as rust preventive oil, lubricating oil, as long as it is within the composition range of the present invention Give full play to the effects of the present invention. In this way, it is possible to obtain a cold-rolled steel sheet and an alloyed hot-dip galvanized steel sheet which not only have excellent deep-drawing properties but also have excellent deformation age hardening properties in which the tensile strength is increased by drawing-heat treatment. Next, the reason why the third invention of the present invention limits the composition of the steel sheet to the aforementioned range will be described. c: 0.01% by mass or less ^ The paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) &quot; -42- (Please read the precautions on the back before filling this page)

565621 Printed by A7 B7, Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of Invention (The less d C content, the better the deep drawing property of the steel sheet, which is more favorable for the formability. Also, after cold rolling, During the annealing process, N b .C remelting is performed to increase the amount of solid solution C in the crystal grains, which easily leads to a reduction in the aging resistance at room temperature. Therefore, the C content is suppressed to less than 0 · 0 1 mass% It is more preferable to be less than 0 _ 0 0 50% by mass; more preferably less than 0 · 0 0 3 0% by mass. In addition, from the viewpoint of ensuring strength and preventing coarsening of crystal grains, the content of C is more than 0 · 0 0 0 5% or more is preferable. Si · · 0.005 to 1.0 mass% si is a useful component for suppressing the reduction in the amount of elongation and improving strength, but if the content is less than 0 · 0 0 5 mass% If it is added, the effect obtained is not much. On the other hand, if it exceeds 1.0% by mass, it will cause deterioration of surface properties and state, and reduce ductility. Therefore, S i is limited to 0. 005 ~ 1 · 0 The range of mass%. The range of 0.01 to 0.75% by mass is better. Mn: 〇.〇l ~ 1.5 The amount% Μ η can not only be used as a strengthening component of steel, but also can form Mn n S and have the effect of suppressing embrittlement caused by S. However, if the amount of Mn η is less than 0.01% by mass, Μ is added. The effect of η is not obvious. On the other hand, if the fruit exceeds 1.5% by mass, the surface properties and state will be deteriorated, and the ductility will be reduced. Therefore, η is limited to the range of 0.001 to 1.5% by mass. A range of 0 · 10 ~ 0 · 75 mass% is better. Ρ: 0 · 10 mass% or less P can be used as a solid solution strengthening component and can effectively help the strengthening of steel. This national paper standard is applicable. CNS) Α4 specification (210X297 mm) &quot; -43- (Please read the precautions on the back before filling in this page) Clothing, 1T

565621 Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 _B7 _V. Invention Description (4), but if the added amount exceeds 0 · 10% by mass, phosphides such as (F e N b) XP will be formed , Thereby reducing deep drawability. Therefore, P is limited to 0.10 mass% or less. S: 0.01 mass% or less If the content of S is too large, the amount of intermediary substances will increase and the ductility will decrease. Therefore, it is best to avoid the incorporation of S as much as possible, but it is allowable to 0.01 mass%. A 1: 0.005 to 0.030% by mass / A 1 series can be added as a deoxidizer or to increase the yield of the carbonitride-forming component, but if the content is less than 0 · 0 0 55% by mass, A sufficient effect cannot be obtained. On the other hand, if it exceeds 0.030% by mass, the amount of N that should be added to the steel is greatly increased, and therefore defects in the steel billet are liable to occur during steel making. Therefore, the content of A1 is set to a range of 0. 005 to 0. 030 mass%. OO: 0. 005 to 0. 040 mass%. N is an important element in the present invention that can exert the function of imparting age hardening properties to a steel sheet. . However, if the content is less than 0.005 mass%, sufficient deformation age hardenability cannot be obtained. On the other hand, if it exceeds 0 4.04 mass%, the punchability will be reduced. Therefore, the N content is set to be in a range of from 0.05 to 0.040% by mass. The range is more preferably from 0.08 to 0.015 mass%. B: 0.00 0 1 to 0.003% by mass B is added together with N b, which can effectively make the hot-rolled metallographic group paper size use Chinese National Standard (CNS) A4 specification (210X29 * 7 mm) ~ ( (Please read the notes on the back before filling out this page) ▼ Order

-44- 565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the invention (D weaving and cold rolling recrystallized metallographic structure is refined, and it has the effect of improving the secondary processing brittleness resistance. However, if the content is insufficient If 0. 0 0 0 1% by mass, a sufficient effect of miniaturization cannot be obtained. On the other hand, if it exceeds 0. 0 0 3% by mass, not only the crystallization amount of BN is increased, but also the Melting in the heating stage is a hindrance. Therefore, the B content is set in the range of 0.0001 to 0.003 mass%. The range of 0.0001 to 0.0015 mass% is particularly preferable, and 0.0007 to 0.0012 mass The range of% is more preferable., Nb: 0.05% to 0.05%. Mass% 1 ^: 0.005 to 0.07% by mass. ¥: 0.005 to 0.001% by mass. % N b, Ti, and V are added together with B, which can effectively refine the hot-rolled metallographic structure and cold-rolled recrystallized metallographic structure, and have the solid solution C fixed to NbC, Ti C, and VC. It can be added together with B if necessary. However, if the content is less than 0.005 mass%, , Its effect is insufficient. On the other hand, if Nb exceeds 0 · 050 mass%; Ti exceeds 0 · 070 mass and exceeds 0 · 10 mass%, the ductility is reduced. Therefore, the Nb content is set to 0 · 005 to 0. 050 mass%, T i content is set to 0.005 to 0.070 mass%, and V content is set to a range of 0. 0 0 5 to 0. 10 mass%. Also, as described above Nb has the effect of solidifying C into Nb C and fixing it. In addition, it can form NbN nitride. Similarly, it can form A1N and BN separately from A1 and B. Therefore, in order to fully ensure The amount of solid solution N, and (please read the precautions on the back before filling this page). # 衣 · 、 11

This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -45- 565621 A7 B7 V. Description of the invention (y and fully reduce the amount of solid solution c, in accordance with the following (1 ◊ (2) formula is It's important. '· 〇〇15 + 14/93 · ΝΙ)% + 14 // 2 7 · A 1% + 1 4/1 1 · Β% ............ (1) C% $ 0 _ 5 · (1 2/9 3) · Ν b% ............ (2). N / A1 or N / (A1 + Nb + T i + v + B) When it exceeds 0.30, A 1 can form A 1 Ν and reduce the solid solution N. In order to ensure a proper amount of solid solution N, it is necessary to set N / A1 to more than 0.30. If Nb, Ti, V, or B is added in combination, N b N, D i N, VN, or BN will be formed to reduce the solid solution N, so in order to ensure a proper amount of solid solution N, it is necessary to N / (A 1 + Nb + Ti + V + B) is set to be more than 0.30. N in a solid solution state is not less than 〇 · 〇〇1 〇% In order to improve the deformation age hardening of the steel sheet, it is necessary to The solid solution N (also referred to as solid solution N) is present in an amount of more than 0.000%. Here, the amount of solid solution N is obtained from steel. The total N amount was obtained by subtracting the amount of crystallization N. As for the analysis method of the amount of crystallization N, the present inventors conducted a comparative review of various analysis methods, and considered that it was based on electrolysis using a constant potential electrolytic method. The extraction analysis method is the most effective. In addition, the method for dissolving the matrix iron used in the extraction analysis includes the acid decomposition method, the halogen method, and the electrolytic method. Among them, the electrolytic method does not allow carbides and nitrides. This paper size applies to the Chinese National Standard (CNS) A4 (210X297) (please read the precautions on the back before filling this page)

Printed by the Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs -46- 565621 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 _____ B7_ V. Description of the Invention (The extremely unstable crystals also decompose, and only The matrix iron dissolves, so it is the most suitable. As the electrolyte, an acetone-based electrolyte is used for electrolysis at a constant potential. In the present invention, the results of the amount of crystallization N measured using the constant potential electrolysis method are shown to be actual. Based on the above-mentioned reasons, in the present invention, the residue extracted by the potentiostatic electrolytic method is chemically decomposed, and the amount of N in the residue is obtained, and this result is regarded as the amount of crystallization N. In addition, in order to To obtain a higher B B amount, / △ TS, the solid solution N amount is preferably more than 0. 0 0 15%, and more preferably more than 0. 0 2 0%, more than 0. 0 0 30% or more is more preferable. The cold-rolled steel sheet of the present invention is a deep-drawing cold-rolled steel sheet having excellent composition and aging hardening properties, which is characterized by TSX r 値 -7 50 MPa. TSX r 値 if below 7 5 〇 Μ Pa can not be widely applied to components with elements of structural members. In order to further expand the scope of application, it is better to set TSx r 値 to more than 850 MPa. 'Traditional The standard conditions for the coating and baking treatment conditions are 170 ° CX 20 minutes. Furthermore, if the steel sheet of the present invention containing a large amount of solid solution N is deformed by more than 5%, even if it is slightly slower (Low temperature side) treatment can also achieve hardening, in other words, the aging conditions can be expanded. In addition, in general, in order to obtain the amount of hardening, as long as it is not softened due to excessive aging, a higher temperature Under the conditions, keep (Please read the precautions on the back before filling this page)

This paper size is in accordance with Chinese National Standard (CNS) A4 (210X 297mm) -47- 565621 Α7 Β7 V. Description of the invention (y longer time is more favorable. (Fill in this page) Specifically, after the pre-deformation of the steel sheet of the present invention, the lower limit of the heating temperature at which the hardening tends to be obvious is about 100 t: In addition, if the heating temperature exceeds 30 crc, hardening will It will become the highest level. If the heating temperature exceeds 400 ot, it will show a tendency to soften, and the phenomenon of thermal deformation and discoloration will become obvious. As for the holding time, when the heating temperature is about 200 ° C When it is maintained for more than 30 seconds, almost full hardening can be achieved. If you want to obtain a larger / more stable hardening, it is best to keep it for more than 60 seconds. However, if it is kept for more than 20 minutes In the above case, not only cannot further hardening be obtained, but the production efficiency will be significantly reduced and impractical.

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Based on the above circumstances, the present invention formulates the aging treatment conditions as follows: Refer to the traditional coating and baking treatment conditions: 1700 ° c x 2 0 m i η for evaluation. The steel sheet system of the present invention can stably achieve a large size even under the conditions of low-temperature heating and short holding time to the extent that conventional coating baking type steel sheets cannot achieve sufficient hardening. hardening. In addition, as for the heating method, there is no particular limitation. Not only can the heating in the gas phase environment of a heating furnace used for general coating and baking treatment be used, but also, for example, electromagnetic induction heating or Oxidizing flame, laser, plasma, etc. for heating. In addition, it is also possible to selectively heat only the portion where the strength is desired. The strength of automotive parts must be able to support complex stresses from the outside. Therefore, the strength characteristics of material steel plates are important not only in a small deformation range, but also in a large deformation range. This paper size applies the Chinese National Standard (CNS) A4 specification (210 × 297 mm) -48- 565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. The invention description (In view of this, the inventors will use the The amount of B 的 of the steel sheet of the present invention to be used as a material for automobile parts is set to be more than 80 Μ Pa and the amount of ΔS is set to be more than 4 OMP a. The amount of BH is set to be more than 10 OMP a and It is more preferable to set the ATS amount to more than 50 MPa. If you want to increase the bh amount and ATS amount, you only need to set the heating temperature during aging treatment to a higher temperature side, and / or set the holding time to more In addition, the steel sheet system of the present invention is provided with "in a state where molding is not performed, and even if it is left at room temperature for a long period of about 1 year, deterioration of aging does not occur (YS increases, and E 1 (elongation reduction phenomenon), which is not available in the conventional steel sheet. In addition, the present invention can also perform hot-dip galvanizing or alloyed hot-dip galvanizing on the surface of the cold-rolled steel sheet of the present invention described above. There will be What's more, it also shows the same level of TS, B Η and △ TS as before galvanizing. As for the types of plating or dip plating other than hot-dip galvanizing or alloyed hot-dip galvanizing, zinc plating is applicable; Dip plating of molten zinc; alloyed molten zinc ore, tin electric ore, complex electric ore; town electric ore, etc. Next, the manufacturing conditions of the fourth invention of the present case will be explained. It will have: c: 0.01% The following; Si: 0.005 to 1.0%; Mn: 〇.〇5% to 1.5%; P: 0.1% or less; S: 0 to 〇1% or less; A1: 0.005 to 〇30%; N: 〇 · 〇〇5 ～ 〇 · 040%; or B: 0 · 0003 ～ 0. 0030% — Nb: 0.0 0 5 ～ 〇.050%; Ti: 0.005 ～ (Please read the notes on the back first (Fill in this page again)

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This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -49- 565621 Α7 Β7 Printing of disasters by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of invention (d 〇 · 070%; V: 〇 · 0〇 One to two or more of 5 to 0 · 10%, and a conventional melting of a steel with a composition of N / (A1 + Nb + Ti + V + B) exceeding 0.30 or more It is melted and made into a steel material by the agglomeration method or continuous casting method. Next, after heating this steel material uniformly, hot rolling is performed to produce a hot-rolled steel sheet. If the heating temperature (SRT) is too low, the processability The improvement effect in this area tends to be saturated, and it will increase the rolling load during hot milk and increase the problems during rolling, or it may cause insufficient uniformity of solid solution N. Therefore, the lower limit of the heating temperature is set to 9 The temperature is preferably 50 ° C. In order to improve the deep drawing property, it is advantageous to fix the solid solution C in advance to crystallize out carbides. Therefore, the heating temperature should be set below 130 ° C. In order to further improve the processability, The temperature is preferably set to less than 1150 ° C. When the overall rolling ratio of rough rolling to refined rolling during hot rolling is set to less than 80%, the fineness of crystal grains of the hot rolled steel sheet is insufficient, Therefore, it is better to set it to more than 80%. In addition, if the rough rolling temperature exceeds 100 ° C, the rα metamorphic grains will become coarse and reduce r 値, if the A3 metamorphosis point is not reached, The α grains will decrease r 値 due to coarsening of recrystallization or grain growth, so the rough rolling system should be performed in a temperature range below 100 ° C and above the A 3 transformation point. On the other hand, if let If the refining roll ends in a temperature region above the AI * 3 transformation point, the r — ^ transformation causes the aggregate structure to become irregular, and excellent deep drawing properties cannot be obtained. On the other hand, even if refining (please first (Read the notes on the back and fill out this page)

This paper size applies the Chinese National Standard (CNS) A4 specifications (210 × 297 mm) -50- 565621 Α7 Β7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs In the end of the range, it is impossible to expect further improvement of deep drawability, and it only increases the rolling load. Therefore, it is advisable to perform the refined rolling in a temperature range below the A 3 transformation point and above 60 ° C. In the case of refining rolling, if lubricating rolling is not performed, an additional shear force will be applied to the surface layer portion of the steel plate due to the friction between the roller and the steel plate. As a result, it will lie in the surface layer of the steel plate. The part preferentially forms a {1 1 0 丨 orientation that is not very good for deep drawability, which causes the deep drawability to deteriorate. Therefore, it is best to perform lubrication / reduction at the same time when refining and rolling. Next, The hot-rolled steel sheet is coiled into a strip shape. The material to be processed after the coiling process is also referred to as "steel strip coil." The higher the coiling temperature (CT) of the hot-rolled steel sheet, the higher the carbonization temperature. The coarsening of things However, if it exceeds 800 ° C, the scale formed on the surface of the hot-rolled steel sheet becomes thicker, which not only increases the burden of removing the scale, but also causes the length of the steel strip coil due to the formation of nitrides. The amount of solid solution N varies. On the other hand, if the coiling temperature is less than 400 ° C, the coiling operation will become difficult. Therefore, the coiling temperature (CT) of the hot-rolled steel sheet must be set to 8 0 0. A range of ~ 4 0 0 t is preferable. Next, the obtained hot-rolled steel sheet is subjected to recrystallization annealing by continuous annealing or batch annealing. The annealing treatment (annealing of the hot-rolled steel sheet) at this time is to make the original The rolling process aggregate structure formed by the hot rolling in the α domain performed during refining rolling is recrystallized to obtain a recrystallized aggregate structure. Next, the hot-rolled steel sheet is cold-rolled to become a cold-rolled steel sheet. Cold rolled (please read the precautions on the back before filling this page)

This paper size applies the Chinese National Standard (CNS) A4 specification (210 × 297 mm) -51-565621 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 ____B7_ V. Description of the invention (The rolling rate is set at 60 ~ The reason is that it is preferably between 95% and 95%. The reason is that if the cold rolling rate is less than 60%, a high r 无法 cannot be achieved. On the other hand, if it exceeds 90%, r 下降 will decrease instead. The cold-rolled steel sheet after the above-mentioned cold rolling is then subjected to a recrystallization annealing treatment. This annealing treatment is preferably performed by using a continuous annealing production line or a continuous molten galvanizing production line. The conditions of annealing treatment and processing are It is preferable to perform a holding (holding) time of 5 seconds or more for more than 650 ° C. The reason is that if the annealing temperature is less than 6 50 ° C or the annealing conditions are not / for 5 seconds, recrystallization cannot be completed Therefore, the low-deep drawing property will be the reason. In order to further improve the deep-drawing property, it is best to use a holding (holding) time of more than 8000 ° C for more than 5 seconds. However, if the annealing temperature exceeds 9 〇0 ° C, carbide Remelting will occur, and solid solution C will be increased excessively, so the delayed aging (aging resistance at room temperature) will be reduced. In addition, if α-r abnormality occurs, the aggregate structure will become irregular, which will reduce r 値Since the deep drawability is impaired, the annealing temperature is preferably set to less than 90 ° C. In addition, for cold-rolled annealed steel sheets obtained by recrystallization annealing cold-rolled steel sheets, hot-dip galvanizing should be performed as necessary. Alternatively, heat-alloying treatment is performed. At this time, the cooling rate from the recrystallization annealing to the time before the plating process is set to 5 ° C / sec or more, and the plate temperature during hot-dip galvanizing is set to The temperature is preferably from 4 0 to 6 0 ° C. When performing the alloying treatment, the processing temperature is set to 400 to 6 0 ° C, and the processing time is preferably 5 to 40 seconds. In addition, the above The cold-rolled steel sheet or hot-dip galvanized paper after recrystallization annealing applies the Chinese National Standard (CNS) A4 specification (210X297 mm) '-52- (Please read the precautions on the back before filling this page).

、 1T Φ 565621 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 _V. Description of the invention (a steel plate, in order to correct the shape and adjust the surface roughness, it is appropriate to implement tempering rolling. The rolling rolling ratio is preferably less than 10%, because if this rolling rolling ratio exceeds 10%, r 降低 will be reduced. Second, in the fifth invention of this case, the steel tension cold rolled steel The reason for limiting the composition: C: 0 · 0015 ~ 0 · 025 mass% or less In order to control the metallographic structure to be uniform and fine and to ensure a sufficient amount of acicular fertilizer grain iron phase, the present invention must set the C content If it exceeds 0.015% by mass or more, on the other hand, if it exceeds 0.025% by mass, the proportion of carbides in the steel sheet is too large, which significantly reduces ductility, r 値, and formability. Therefore, The C content is limited to the range of 0.005 to 0.25 mass%. From the standpoint of improving moldability, it is preferable that the content be 0.002 mass% or less, and 0.001 mass. % Is particularly preferred. In addition, based on making β From the viewpoint of material stability, it is better to set the C content to (1.2 / 9 3) N b (%). S i: 1 · 0% by mass or less. The Si system will not significantly reduce the steel content. Ductility is also a useful element for improving the strength of steel plates. In the present invention, it is preferable to contain 0. 05% by mass or more, especially when high strength is required, and it is more preferable to contain 0. 10% by mass or more. On the other hand, Si is also because the abnormal point is greatly increased during hot rolling, and it is difficult to ensure the quality and shape of the steel sheet, or it has a negative impact on the surface properties and conditions, chemical treatment, etc., especially the aesthetics of the surface of the steel sheet. This element is one of the elements that damage the electroplating property, so the present invention is applicable to the Chinese National Standard (CNS) A4 specification (2i × 297 mm) for this paper size. '--53- (Please read the precautions on the back before filling this page) Clothing., -Mouth

565621 Α7 Β7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (5) Limit it to less than 1.0% by mass. If si is limited to 1.0% by mass or less, the above-mentioned adverse effects can be suppressed to a very low level. In addition, in applications where the aesthetics of the surface of a steel sheet is particularly required, it is preferable to limit S i to 0.5% by mass or less. Μη: 2.0% by mass or less. Μη is an effective element that prevents thermal cracking due to S. It can be added in accordance with the S content. In addition, Μη is effective for miniaturizing crystal grains and can be used as a material. Improve the elements to add. From the viewpoint of stabilizing / fixing S, it is preferable that the amount of Mη is more than 0.1% by mass. The M η is an element that can increase the strength of the steel sheet. If a higher strength is required, the M η is preferably more than 0.5% by mass. It is more preferably more than 0.8% by mass. Increasing the Mη content to such a degree has the great advantage of significantly improving the mechanical properties of the steel sheet, particularly the changes in the deformation age hardening properties, against changes in hot rolling conditions. However, if the amount of M η is excessively greater than 2.0% by mass, although the detailed reason is unknown, there is a tendency to increase the resistance to thermal deformation, and the weldability and formability of the welded portion may be deteriorated. The tendency tends to significantly suppress the production of ferrous iron and significantly reduce ductility, and the tendency to decrease r 値 also tends to be obvious. Therefore, M η is limited to 2.0% by mass or less. For applications requiring better corrosion resistance and moldability, it is preferable to limit M η to 1.5% by mass or less. ρ: 0.1% by mass or less ρ can be used as a solid solution strengthening element of steel, based on the viewpoint of increasing strength (please read the precautions on the back before filling this page). 1T

This paper size applies the Chinese National Standard (CNS) A4 specification (210 x 297 mm) -54- 565621 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7_ V. Description of the invention It is preferably more than mass%, especially when high strength is required, and it is better to contain more than 0.002 mass% or more. On the other hand, if the content is too much, it will cause brittleness of the steel, and then make the steel sheet The workability of the stretched flange deteriorates. Moreover, p tends to crystallize in steel, so the embrittlement of the welded part is caused by the crystallization of p. Therefore, P is limited to 0. 1% by mass or less. In addition, in applications where the workability of stretch flanges and the toughness of welded parts are particularly important, it is preferable to set p to 0. 08 mass% or less. More preferably, 0.06 mass% or less. / S: 0.02 Mass% or less S exists as an intermediary in the steel sheet, and it is an element that reduces the ductility of the steel sheet and further deteriorates the corrosion resistance. Therefore, it is best to reduce the content as much as possible. In the present invention, S is limited to 0.02 mass. % Or less. It is particularly important For applications with good processability, it is desirable to limit s to 0. 0 '15 mass% or less. When excellent stretch flange processability is required, it is desirable to limit S to 0.010 mass% or less. In addition, although the detailed mechanism of action is unknown, it is effective to reduce S to less than or equal to 0.8% by mass in order to make the deformation age hardening of the steel sheet stable and maintain a high level. A 1: 0 · 〇2 mass% or less A 1 is an element which can be used as a deoxidizing agent to improve the cleanliness of steel and to refine the structure of the steel sheet. In the present invention, it contains 0.01 mass% or more. In the present invention, although N in the solid solution state is used as a strengthening element, an aluminum all-static steel containing A 1 in a proper range has better performance than a conventional non-static steel without adding A 1. Mechanical. On the other hand, if this paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) I-55- (Please read the notes on the back before filling this page) Printed by Employee Consumer Cooperative 565621 A7 B7 Note (If y contains too much A 1, the surface state and properties of the steel sheet will be deteriorated, and N in the solid solution state will be significantly reduced, so that the effect of obtaining a great amount of deformation age hardening which is important in the present invention will be changed. It is very difficult. For these reasons, in the present invention, A 1 is limited to 0. 02% by mass or less. In addition, from the viewpoint of the stability of the material, A 1 is limited to 0.001 to 0.0015. The mass% is more preferable. Although reducing the content of A1 may cause coarsening of crystal grains, the present invention is to optimize the content of other alloying elements and to select the fire bars / pieces. In the most appropriate range, this problem can be prevented. N: 0.005 to 0.0250 mass% N is an element that can increase the strength of the steel sheet by solid solution strengthening and deformation age hardening, and is also the most important element in the present invention. In addition, the present invention can ensure necessary and necessary cold-rolled products or electroplated products by containing a proper amount of N, further adjusting the content of A 1 to a proper value, and controlling manufacturing conditions such as hot rolling conditions and annealing conditions. N in a fully solidified state. In this way, the effects of solid solution strengthening and increasing strength (depressed stress and tensile strength) due to deformation and age hardening can be fully exerted, and the so-called "tensile strength of 3 40 MPa or more, The amount of baking hardening (B Η amount) is 80 MPa or more, and the amount of increase in tensile strength before and after deformation aging treatment ΔTS 40 MPa or more is the target of mechanical properties of the steel sheet of the present invention. In addition, N has a function of lowering the abnormal point, and if N is contained, it is effective in the case of rolling a thin object that does not want to be greatly cut into the abnormal point. If the N content is less than 0.0050 mass%, the above-mentioned paper size applies the national standard of the week (CNS &gt; A4 size (210X297 mm) '-56- (Please read the precautions on the back before filling this page)

565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the invention (The effect of increasing the degree is difficult to show steadily. On the other hand, if it exceeds 0.025% by mass, the incidence of internal defects in the steel plate will be It becomes high, and cracks and the like of the steel billet often occur during continuous casting. Therefore, the N content is set to a range of 0.005 ◦ to 0.00250 mass%. In addition, if it is based on consideration to the entire manufacturing process In terms of the stability of the material and the improvement of the yield rate, N is limited to a range of 0 · 0 7 to 〇 0 2 0 0 mass%, and even N is limited to 〇 · 〇1 0〇 ~ 0 · 〇 1 70% by mass is more preferable. As long as the N content is within the range of the present invention, there will be no adverse effect on weldability and the like. N: 0 · 0 0 1 0% or more In order to ensure sufficient strength of the cold-rolled product and to effectively exert the deformation age hardening caused by containing N, the solid state N (also referred to as solid solution N) in the steel sheet must be at least more than 0 · 0 0 1 0% or more exists. Here, The amount of solid solution N is obtained by subtracting the amount of crystallization N from the total amount of N in the steel. As for the analysis method of the amount of crystallization N, the present inventors conducted a comparative review of various analysis methods and considered it to be The most effective method is the electrolytic extraction analysis method using a constant potential electrolytic method. In addition, the method for dissolving matrix iron used in the extraction analysis includes an acid decomposition method, a halogen method, and an electrolytic method. Among them, electrolysis This method is most suitable because it will not cause the extremely unstable crystals such as carbides and nitrides to dissolve, but can only dissolve the matrix iron stably. As the electrolyte, an acetone-based electrolyte is used to stabilize the potential. Electrolysis is performed. It is shown in the present invention that the paper size applied by the constant potential electrolysis method is applicable to the Chinese National Standard (CNS) A4 scale (210X297 mm) (Please read the precautions on the back before filling this page) -57- 565621 A7 B7 V. Description of the invention (^ The result of the measured amount of crystallization N is the most corresponding to the actual strength of the part. {Please read the precautions on the back before filling this page) Based on the above reasons, the present invention will use the After chemical decomposition of the residue extracted by the in-situ electrolysis method, the amount of N in the residue is obtained, and the result is regarded as the amount of crystallization N. In addition, in order to obtain a high BH amount, ATS, the solid solution N amount is more than 0 · 0 0 2 0% or more is preferable, and in order to obtain a higher BH amount, Z \ TS, the solid solution N amount is more preferably more than 0.0030%. The upper limit of the solid solution N amount is not particularly limited, though However, even if all the amount of N remains, the reduction in mechanical properties is very small. 0 N / A 1 (the ratio of N content to A 1 content): 0 · 3 or more employees of the Intellectual Property Bureau of the Ministry of Economic Affairs Consumption cooperative seal ^ In order that solid N in the product state can remain stably more than 0. 0 0 1 0 mass% or more, the amount of elements that can be used to strongly fix N, that is, A 1 must be limited. The combination ratio of the N content (0.005 ◦ to 0. 025 0 mass%) and the A1 content (0. 02 mass% or less) within the composition range of the present invention is performed in a wide range. As a result of the review of various changed steel sheets, we learned that by setting N / Al (the ratio of the N content to the A1 content 値) to: 0.3 or more, the solid-rolled N in cold-rolled products and electroplated products can be Stabilized to more than 0_0010% by mass. Therefore, N / A 1 is limited to 0.3 or more. In addition, from the viewpoint of improving the deformation aging hardening property and stabilizing it, it is desirable to set the N / A 1 system to 0 or more. It is better to set it to 0 · 8 or more.

Nb: 0.002 to 0.050% by mass. This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X297 mm) -58- 565621 Α7 Β7 Printed by the 8th Industrial Cooperative Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. When N b is added together with B, it can effectively help to produce acicular fertilizer grain iron phase, and the present invention must contain more than 0.002 mass%. On the other hand, if the content exceeds 0.050 mass%, , Not only the effect tends to be saturated, but also significantly increases the hot deformation resistance, making hot rolling difficult. Therefore, the Nb is limited to the range of 0.002 ~ 0.05% by mass. Again, 〇. 〇〇 A range of 5 to 0,040% by mass is particularly preferred. B: 〇. 〇〇〇〇1 ～ 〇 · 〇050% by mass / B and N b are added together, which can effectively help to produce acicular fertilizer phase iron phase In the present invention, it is necessary to contain more than 0.0001 mass%. On the other hand, if the content exceeds 0.0050 mass%, the amount of solid solution N that is helpful for deformation age hardening will be reduced. Therefore, Limit B to 〇〇〇〇〇〇〜〇〇〇〇 05 The range of mass%. The range of 0.0003 to 0.0000% by mass is more preferable; 〇_00〇5 ~ 0.030% by mass is particularly preferable. The present invention contains the following a to c groups in addition to the above composition. One group or two or more of them are preferable. A group: one or two or more of Cu, Ni, Cr, and Mo, totaling less than 1.0%; b group: among T i and V One or two or more, with a total of less than 0.1%; c group: one or two of Ca and REM, a total of 0.000-10.0 to 0. 010%. Elements of group a: Cu, Ni, Cr and Μο are both for promotion (please read the precautions on the back before filling this page). The size of the paper is applicable to the Chinese National Standard (CNS) Α4 specification (21 〇 × 297 mm) -59- 565621 A7 B7 Ministry of Economic Affairs Printed by the Intellectual Property Bureau's Consumer Cooperatives. 5. Description of the invention (g Steel plate strength elements can be selectively added individually or in combination according to demand. This effect requires Cu: 0 · 0.1% or more, Ni:, 0 · 01% or more, Cr: 0 · 01% or more, Mo: 0.01% or more, it will appear. However, if the content is too high, not only It will increase the resistance to hot-rolling deformation, or deteriorate the chemical treatment properties and broad surface treatment properties. It will also cause the welded part to harden and deteriorate the formability of the welded part. Therefore, when the elements of group a are separate, they are CU: 1. 0% or less, Ni: 1.0% or less, Cr: 〇_5% or less, M 〇: 〇2% or less is preferable, and if it is added in combination, the total is less than 1. 0% is preferred. The elements of the b group: T i and V are both elements which are helpful for miniaturizing and homogenizing crystal particles, and therefore may optionally contain one or two of them as necessary. This effect is required to contain Ti: 0.005% or more; V: 0.05% or more will appear. However, if the content is too large, it will increase the hot rolling deformation resistance, or lead to chemical treatment characteristics, generalized Surface treatment characteristics deteriorate. There is also the concern of reducing the amount of solid solution N. Therefore, when the elements of the b group are separate, it is preferably less than 0.1% or less, and if they are added in combination, the total amount is preferably less than 0.1%. Elements of group c: Ca and REM are both elements that are helpful for controlling the form of the intermediary substance, especially in the case of the requirement of the moldability of the extended flange. It is best to contain the elements of group c alone or in combination. . In this case, if the total content of group C is less than 0. 〇Q 1 0%, the effect of controlling the form of the intermediary substance is insufficient. On the contrary, if (Please read the precautions on the back before filling in this Page) • Contention, 11

This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -60-565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the invention Surface defects occur. Therefore, the content of the elements of the C group is preferably limited to a total range of 0 · 0 〇1 0 to. 〇 0 0 0%. In this way, the stretch flange forming processability can be improved. However, surface defects do not occur. Next, the metallographic structure of the steel sheet of the present invention will be described. The steel sheet of the present invention has an area ratio of 5% or more of needle-shaped ferrous iron phases and an average crystal grain size of 20 / m or less. Metallographic structure composed of ferrous grain iron phases. Area ratio of acicular ferrous iron phases: 5% or more The cold-rolled steel sheet of the present invention contains acicular ferrous iron phases with an area ratio of 5% or more. Contains an area ratio of acicular fertilizer grains of 5% or more, which can obtain good ductility and further obtain a large amount of deformation and age hardening. Although the detailed mechanism of action is unknown, it is speculated that: because of acicular fertilizer The presence of the granular iron phase The inside is very effective for storing the deformation during pre-deformation before aging. In addition, the presence of acicular ferrous iron phase is also helpful to improve the aging deterioration at room temperature and make the steel plate non-aging at room temperature. Also In order to obtain a good balance between strength and ductility, as well as higher strength, the area ratio of the iron phase of the acicular fertilizer particles is preferably more than 10%. In addition, if the area ratio of the iron phase of the acicular fertilizer particles is more than 20%. If it is more than%, there is a problem that r 値 is reduced. Therefore, it is desirable to set the area ratio of the iron phase of the acicular fertilizer particles to 5% or more, and more preferably 10% or more, but not more than 20%. The acicular fertile iron phase referred to in the invention is a low-temperature metamorphic phase that does not contain carbides, which is unique to the extremely low carbon steel of the composition of the present invention. (Please read the precautions on the back before filling in this page)

、 1T This paper size is applicable to the National Standard (CNS) A4 specification (210X29 * 7mm) -61-565621 A7 B7 V. Description of the invention (d) If you observe it with an optical microscope, you can clearly distinguish it from ordinary polygons Different fertile iron phases, the internal index density is very high, compared with polygonal ferrous iron phases, the hardness is higher. According to the observation of the optical microscope, the acicular. Fertile iron phases are: (1). Grain boundary Crystal grains with irregularly protruding angles; (2) Crystal grains that exist at the grain boundary like crystals; (3) Crystal grains or clusters of crystal grains (in larger Among the particles of the second phase, many subgrain boundaries can be seen). One of the three states is distributed separately or in combination, which is clearly different from the general polygonal fertile grain iron phase. In addition, the corrosion tone in the grain is also different from As Matana loose iron and toughened iron are almost the same as ordinary polygonal fertile iron, so it can be clearly distinguished from Asada loose iron and toughened iron. According to observation by transmission electron microscope, the acicular fat iron phase, At its grain boundary And / or the intra-grain translocation density is very high, in particular, the part with a very high translocation density and the relatively low part in the metallographic structure in the state (3) described above form a layer. The cold-rolled steel sheet system of the present invention For steel plates for automobiles that require high formability, in order to ensure ductility, the metallurgical structure other than the acicular ferrous iron phase uses the ferrous iron phase. If the area ratio of the ferrous iron phase is less than 80% If it is used as a steel sheet for automobiles that requires high workability, it is difficult to ensure its ductility and high r 値. In addition, if it needs to have good ductility, the area ratio of the ferrous iron phase is more than 80% It is even better to exceed 85%. In addition, the "fertilized iron" as referred to in the present invention refers to a "polygonal ferrous iron" in a state in which it does not remain deformed. The average crystal grain size of the ferrous iron phase: 2 0 // m This paper size applies to Chinese National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page)

、 1T Φ Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs-62- Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 A7 ___B7_ V. Description of the Invention (1) The average crystal grain size in the present invention is from: The specified area calculation method is based on the cross-section structure photo and the calculated number; and the nominal particle size obtained from the cross-section structure photo by the cutting method prescribed by AS TM (please refer to: ". Heat Treatment" 2 4 (1984), P334). The cold-rolled steel sheet of the present invention has a predetermined amount of solidified N in the product stage, but according to the inventor, As a result of experiments and reviews, it was found that even for steel plates having the same amount of solidified N, one of the main reasons is that the crystal grain size is due to changes in the deformation / aging hardenability. In such a metallurgical structure of the present invention, by setting the average crystal grain size to be at least less than 20 # m or less, and preferably 1 5 // m or less, a high B Η amount, △ TS can be obtained stably. ... its mechanism of action Although it was not clear before, it can be inferred that one of the reasons for the change in aging and hardenability is the crystal grain size, and it is partially crystallized with the alloy element or crystallized at the boundary of the crystal particles, and the effects of processing and heat treatment are all It is related. Therefore, in order to stabilize the aging and hardenability of deformation, it is necessary to set the average crystal grain size of the ferrous iron phase to be less than 2 0 // m, and more preferably less than 1 5 // m. The structure of the cold-rolled steel sheet of the present invention has a high tensile strength (TS) of more than 3 40 MPa, more than about 590 MPa, and r 値 more than 1.2. It has excellent deformation age hardening properties. Cold-rolled steel sheet. If it is a steel sheet with TS less than 3 4 OM Pa, it cannot be widely used in structural members. ^ Paper size applies Chinese National Standard (CNS) A4 specification (210X297 mm)-&quot; -63- (Please read the notes on the back before filling this page)

565621 Α7 Β7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the invention (body. If you want to expand the scope of application, τ s is set to more than 4,000 MPa. It is also appropriate. If r 値If it is 1_2, it cannot be applied to a wide range of stamped parts. Moreover, r 値 has a better range of 1.3 or more. The traditional coating and baking treatment conditions are: 1 7 0 t X 20 mi η is used as a standard. In addition, when a deformation amount of more than 5% is applied to a steel sheet of the present invention containing a large amount of solid solution n, even if a slower (lower temperature) treatment is performed, it can be reduced to zero. In other words, the conditions of aging treatment can be broadened. Generally speaking, in order to obtain the hardening amount, as long as it is not softened due to excessive aging, it will be kept longer under higher temperature conditions. Specifically, the lower limit of the heating temperature of the steel sheet of the present invention after pre-deformation tends to be noticeably hardened is about 100 ° c. In addition, if the heating temperature exceeds 300 ° C, hard It will become the highest degree, and it will not only show a slight softening tendency, but also the phenomenon of thermal deformation and discoloration will become obvious. In addition, as for the holding time, when the heating temperature is about 2000 ° C, it will remain more than about Nearly sufficient hardening can be achieved for more than 30 seconds. If you want to obtain greater and more stable hardening, it is best to keep it for more than 60 seconds. However, if it is kept for more than 20 minutes, not only can not get more Further hardening will obviously reduce the production efficiency, which is not practical. Based on the above, the present invention sets the aging treatment conditions as follows: Refer to the traditional coating and baking treatment conditions: 1 70 ° CX 2 0 mi η to Evaluate. Even if it fails to reach the traditional coating and baking type steel plate (please read the precautions on the back before filling this page) 1 «§ Packing. Order Φ This paper size applies to Chinese National Standard (CNS) Α4 Specifications (210X297 mm) -64- 565621 A7 B7 V. Description of the invention (low temperature heating to a sufficient degree of hardening and aging treatment conditions with a short holding time Next, the steel sheet system of the present invention can stably achieve large hardening. In addition, the method of heating is not particularly limited, and not only the gas from a heating furnace used in general coating baking treatment can be used. The phase environment heating method can also be used, for example, electromagnetic induction heating, or heating using flames, lasers, plasmas, etc. that do not oxidize. The strength of automotive parts must be able to bear complex stresses from the outside, so The material steel sheet is not only important in strength / characteristics in a small deformation range, but also in strength characteristics in a large deformation range. In view of this, the present inventors will use this as a material for automotive parts. The B Η amount (corresponding to the strength characteristics of the smaller deformation domain) of the inventive steel sheet is set to exceed 8 OMP a or more, and the ATS amount (corresponding to the strength characteristics of the larger deformation domain) is set to exceed 4 0 Μ P a or more. To increase the amount of B B and Δ T S, it is sufficient to set the heating temperature during the aging treatment to a higher temperature side and / or set the holding time to be longer. Although the effect of the present invention can be exerted even when the thickness of the steel sheet is relatively thick, if the thickness exceeds 3.2 mm, a sufficient cooling rate cannot be ensured during the annealing process of the cold-rolled steel sheet, and continuous Deformation aging occurs during annealing, and it becomes difficult to obtain the desired deformation aging hardenability of the product. Therefore, the thickness of the steel sheet of the present invention is preferably set to 3.2 mm or less. In addition, the present invention may be performed by electroplating or hot-dip plating on the surface of the cold-rolled steel sheet of the present invention. This electroplated or dip-coated steel sheet also shows that the paper size is in accordance with the Chinese National Standard (CNS) A4 (210X297 mm) (please read the precautions on the back before filling this page) »Staff of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by the Consumer Cooperatives-65- 565621 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 _ B7 V. Description of the invention (or the same level of TS, B, and △ TS as before dipping. As for electroplating or dipping The types are applicable: electroplating of zinc; immersion plating of molten zinc; immersion plating of alloyed molten zinc; electroplating of tin; electroplating of chromium; electroplating of nickel; etc. Next, the sixth invention of the present invention, a method for manufacturing a steel sheet, will be described. The steel sheet of the present invention is basically a steel billet having a composition within the above range, and then rough-rolled to form a steel sheet for a thin plate. The steel sheet for the thin plate is sequentially implemented: refined rolling, refining After the rolling is completed, a hot rolling process of cooling and coiling into a hot rolled steel sheet is performed; for the hot rolled steel sheet / pickling and cold rolling to make a cold rolled steel sheet; and for the cold rolled steel sheet, Manufactured by continuous annealing of a cold-rolled steel sheet. The steel billet used in the manufacturing method of the present invention is preferably made by a continuous casting method in order to prevent huge crystallization of the components, but It can also be made by the block making method and the thin steel billet casting method. In addition, after the steel billet is manufactured, in addition to the traditional method of first cooling to room temperature and then heating it again, A direct feed rolling method in which the hot sheet is kept in the original state after being cooled and then directly sent to a heating furnace for rolling; or after a slight heat preservation and heating, a direct rolling method such as a direct rolling method can also be used to save energy. It is applicable without any problems. In particular, when it is desired to effectively ensure the N in the solid solution state, the direct feed rolling method is one of the effective technologies. First, the reason for limiting the conditions of the hot rolling process will be explained. Heating temperature: 1 0 0 0 The heating temperature of the steel billet is in order to ensure that it is necessary in the initial state and the paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) '-66- (please first Note Complete this page and then read it back)

565621 A7 B7 V. Description of the Invention (The amount of solid solution N in cents, and it can meet the target of solid solution N in the state of the product. It is better to set it above 100 ° C. In addition, in order to avoid The increase in the loss caused by the increase of the oxidized weight is preferably set at 1280 ° C or lower. The steel billet material heated under the above conditions is rough-rolled to form a steel sheet for thin plates. In addition, the conditions for rough rolling do not need to be specifically specified, as long as it is generally performed in accordance with a commonly used method. However, from the viewpoint of ensuring the amount of solid solution N, it is better to perform it in a shorter time as possible. Continued / Next, the steel sheets for thin plates are refined and rolled to form hot-rolled steel sheets. The present invention is to join the steel sheets for thin plates located in front and back of each other between rough rolling and refined rolling, so as to continuously It is preferable to perform rolling. As the joining means, a method such as a crimping method, a laser welding method, or an electron beam welding method is preferably used. By performing continuous rolling, the front end portion of the steel strip coil (to-be-processed material) is applied. And the back end, which is The proportion of non-steady parts that are prone to distorted shapes is reduced, and the stable hot-rolled length (continuous length that can be rolled under the same conditions) and width can be extended. This is not only for hot-rolled steel sheets, but also for hot-rolled steel sheets. It is also effective to improve the cross-sectional shape and dimensional accuracy of cold-rolled steel sheet. Also, even after rolling and cooling on the heat transfer platform, tension can be applied, so the good shape of the steel sheet can be maintained. Also, because Continuous roll rolling is performed so that the leading end of the steel strip coil can pass through the rolls stably. Therefore, the traditional single-roll rolling for individual sheet steel sheets will be caused by the steel sheet's passability or biteability. It is difficult to implement lubricating rolls that are difficult to implement because the paper size for rolling is applicable to Chinese National Standard (CNS) A4 (210X297 mm) (Please read the precautions on the back before filling this page)

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs of the 1T-67-565621 A7 B7 V. Description of the invention (y The load and the pressure on the roll surface are reduced, so the life of the roll is prolonged. In the present invention, it is best to Between rolling and refining rolling, a steel sheet edge heater that can heat the widthwise end of the steel sheet and a steel sheet heater that can heat the longitudinal end of the steel sheet are used. It is suitable to uniformize the temperature distribution in the width direction and the length direction of the steel sheet for thin plates. In this way, the material variation in the steel sheet can be further reduced. Based on the stability in work For consideration, it is better to use a sheet steel edge heater for sheet metal and a sheet steel heater / electromagnetic induction heating method. For the above steps, it is best to use the sheet metal edge heater for sheet metal to compensate for the width of the steel plate. The temperature difference at this time is suitable. Although the amount of heating at this time varies depending on the composition of the steel, it is preferable to set the heating amount in the width direction on the exit side of the refined roll. The temperature distribution range is less than about 20 ° C. Next, the steel plate heater for the thin plate is used to compensate the temperature difference in the length direction. The heating amount at this time is set so that the temperature at the end portion in the length direction is lower than The temperature at the center is preferably about 20 ° C higher. The temperature at the exit side of the refined roll: more than 800 ° C. The temperature FDT at the exit side of the refined roll is in order to make the metallographic structure of the steel sheet tend to For uniformity and fineness, it is set to be more than 800 ° C. If FDT is lower than 800 ° C, it will lead to heterogeneous metallographic structure, and some of the processed structure will remain, even after cold After the rolling and annealing process, the non-uniformity of the metallographic structure cannot be eliminated and remains. Therefore, the risk of various problems during punching will increase. This residual phenomenon of the processed structure can be used to The winding temperature is set to a high temperature to avoid the paper size applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) _ (Please read the precautions on the back before filling this page) Order Printed by Fei Cooperatives -68-565621 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 _ B7_ V. Description of the invention (. However, if the coiling temperature is increased, the crystal particles will become coarse, and the same problem will occur In addition, if the coiling temperature is set to a high temperature, the amount of solid solution N will be significantly reduced, and it will be difficult to obtain a tensile strength of 3 4 Ο Μ Pa or higher for the target 値. Therefore, the refined. Rolling exit side The temperature F. DT is set to more than 800 ° C. If you want to further improve the mechanical properties, the temperature FDT of the exit side of the refined roll is set to be more than 8200 ° C. Also, Based on the viewpoint of improving r 値, the FDT is set to: A c 3 or more abnormal point is gui. In addition, although the upper limit of F D T is not particularly limited, if it is too high, the occurrence of scale defects will increase significantly. Therefore, the upper limit of F D T is preferably about 100 ° C. Coiling temperature: less than 8 0 t. As the coiling temperature C T decreases, the strength of the steel sheet tends to increase. In order to ensure the target 値 of the tensile strength T S 3 4 0 Μ Pa or higher, it is preferable to set C T to be lower than 800 ° C. In addition, if C T is lower than 200 ° C, the shape of the steel sheet during coiling is likely to be disordered, and the risk of problems in actual operation becomes higher, and the homogeneity of the material tends to decrease. Therefore, it is advisable to set C T to be higher than 200 ° C or higher. In addition, if better uniformity of material is required, it is better to set the C T port to 3 0 0 C or higher. It is best to set CT to higher than 3 50 ° C. In the present invention, in refining rolling, in order to reduce the hot rolling load, lubricating rolling may be performed. By performing lubricating rolling, it is possible to obtain a more uniform shape and material of the hot-rolled steel sheet. In addition, the size of the friction paper used for lubricating rolls is subject to the Chinese National Standard (CNS) 槻 210 (210x297 mm)-&-quot; -69- (Please read the precautions on the back before filling this page) | .

、 1T 565621 A7 __ B7 V. Description of the invention (6) The coefficient of wiping is set in the range of: 0 · 2 5 ~ 0. 1 0. In addition, a combination of lubricating rolling and continuous rolling can be used to stabilize hot work. After the hot-rolled steel sheet having been subjected to the above-mentioned hot rolling process, the cold rolling process is then used to perform pickling and cold rolling to turn it into a cold rolled steel sheet. The conditions for the pickling are only those which are generally known, and need not be particularly limited. When the scale of the hot-rolled steel sheet is extremely thin, cold rolling can be performed directly without performing pickling. / The conditions for cold rolling are only those which are generally known, and do not need to be particularly limited. In addition, from the viewpoint of ensuring the uniformity of the structure, it is preferable to set the rolling rate of the cold rolling to more than 60%. Next, the reason for limiting the conditions of the annealing process of the cold-rolled steel sheet will be explained. The cold-rolled steel sheet is again implemented: a cold-rolled steel sheet annealing process consisting of continuous annealing and cooling. Continuous annealing temperature: The temperature in the dual-phase coexistence domain of the ferrous iron phase and the Vostian iron phase is set by setting the annealing temperature of the continuous annealing process in the dual-phase coexistence domain of the ferrous iron phase and the Vostian iron phase. At temperature, acicular fertile iron phases will form. In addition, the aggregate structure of 丨 1 1 1 丨 in the ferrous phase of iron is also very developed, so high r 値 can be obtained. On the other hand, if the temperature exceeds the dual-phase coexistence region of the ferrous grain iron phase and the Vostian iron phase and becomes a single phase of Vostian iron, the aggregate structure of the steel plate will be irregular due to the inverter state and the abnormal state. Reduce r 値. Therefore, in the present invention, the annealing temperature in the continuous annealing process is set to a temperature in a dual-phase coexistence region of the ferrous iron phase and the Vostian iron phase. In addition, the basic paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 7 --- (Please read the precautions on the back before filling this page)

1T Φ Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs-70- Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 A7 ___ B7 V. Description of the Invention (d) The consideration of the stability of r 値 is set at: The temperature of Vostian iron is preferably from 10% to 50%. If the annealing temperature is not higher than the recrystallization temperature, the ductility will be reduced, so it can only be used for automotive parts. For special purposes, it is better to set the continuous annealing temperature to be higher than the recrystallization temperature. The holding (maintenance) time of the continuous annealing temperature is based on: production efficiency, refinement of the metallographic structure, and ensuring the desired From the viewpoint of the amount of solid solution N, the continuous annealing temperature is maintained (maintained). The shorter the time, the better, but based on the stability of the operation / industry, it is better to set it to 10 seconds or more. Based on: From the viewpoint of miniaturizing the metallographic structure and ensuring the desired amount of solidified N, it is desirable that the holding (maintaining) time of the continuous annealing temperature is less than 90 seconds. In addition, based on the consideration of material stabilization, It is appropriate that the holding (maintaining) time of the continuous annealing temperature is higher than 20 seconds. Cooling after continuous annealing: cooling is performed at a cooling rate of 10 to 300 ° C / second until it is lower than 50 ° C Based on the viewpoints of ensuring the refinement of the metallographic structure, the formation of acicular fertile iron phases, and the desired amount of solidified N, the cooling system after uniform heating during continuous annealing is very important. In the present invention, The "uniform heating and cooling treatment" is continuous cooling at a cooling rate of at least 10 ° C / sec. To a temperature range below 50 0 C. If the cooling rate is less than 10 t / sec., It is difficult to ensure the necessary amount of acicular fertile iron phase; a uniform and fine metallographic structure; and a sufficient amount of solidified N. On the other hand, if the cooling rate exceeds 300 ° C / sec, then The consistency of the material in the width direction of the steel plate will tend to be insufficient. The paper size applies to the Chinese National Standard (CNS) A4 specification (210X297 mm) at 10 ~ 300 / sec. 1 ~ -71-'(Please first (Read the notes on the back and fill out this page)

565621 A7 B7 V. Description of the Invention If the cooling termination temperature for cooling is higher than 500 ° C, the metallographic structure cannot be refined. Tempering rolling or smoothing Processing: elongation of 0.5 ~ 10% In addition, the present invention is after the cold-rolled steel sheet annealing process, based on the purpose of correcting the shape and adjusting the thickness, the elongation of 0.5 to 10% can also be implemented Rolling or smoothing. If the total elongation during temper rolling or smoothing is less than 0.5%, the intended purpose of correcting the shape and adjusting the thickness cannot be achieved .. On the other hand, if the elongation is If the total amount exceeds 10%, the ductility will decrease. From the viewpoint of ensuring ductility, it is preferable that the ductility is less than 5%. In addition, although the processing forms of temper rolling and smoothing are different, the inventors It has been confirmed that there is not much difference between the two in terms of aging and hardening of the steel sheet. In addition, the temper rolling and smoothing processes are effective even after the plating process. Next, the present description will be described. The reason for limiting the composition of the high-tensile cold-rolled steel sheet according to the seventh invention of the present invention is: C: 0.025% to 0.15% by mass or less. C is an element that can increase the strength of the steel sheet. In order to make one of the important constituent elements of the present invention, The metallographic structure is controlled to be uniform and fine, and to ensure a sufficient amount of Asada's loose iron phase, the present invention must set the C content to more than 0.025 mass%. On the other hand, if it exceeds 0.115 mass%, the steel sheet If the proportion of carbides is too large, the ductility will be significantly reduced, and then the moldability will be significantly affected. In addition, there is a more important problem is that if the C content exceeds 0.15% by mass, it will significantly reduce Paper size applies Chinese National Standard (CNS) A4 specification (210 × 297 mm) · (Please read the precautions on the back before filling this page) 1 «· Packing ·

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs of 1T-72-565621 A7 ___ B7_ V. Description of the invention (d. Decrease the weldability of spot welding, arc welding, etc. For these reasons, the C content is limited to 0.025 to 0.55% by mass. From the viewpoint of improving moldability, it is preferably 0.8% by mass or less. In addition, for applications requiring particularly good ductility, it is It is more preferably 0. 05 mass% or less. In addition, from the viewpoint of stabilizing the amount of B and the material, it is preferable to set the C content to (1 2/9 3) N b (%). S i: 1 · 0 mass% or less / S i series will not significantly reduce the ductility of the steel, but it is also a useful element for improving the strength of the steel sheet. In the present invention, it is desirable to contain 0 · 0 0 5 mass% or more, especially because it requires high For strength, it is more preferable to contain at least 0.1% by mass. On the other hand, S i also significantly increases the transformation point during hot rolling, and it is difficult to ensure the quality and shape of the steel sheet, or the surface properties and conditions. And chemical treatment, especially the beauty of the steel surface This element is one of the elements that adversely affects the properties and further impairs the electroplating properties. Therefore, the present invention limits it to 1.0% by mass or less. If the si is limited to 1.0% by mass or less, the above-mentioned defects can be reduced. The influence is suppressed to a very low level. In addition, in applications where high strength is not required but the aesthetics of the surface of the steel sheet is particularly required, it is preferable to limit si to 0.5.5% by mass or less.

Mn: 2.0% by mass or less. Mn is an effective element that prevents thermal cracking caused by S. It may be added in accordance with the S content. In addition, Mn is effective for miniaturizing crystal grains and can be improved as a material. Use elements to add. In addition, Μ η is in the rapid cooling after continuous annealing. For the stable production of Asada loose iron, the paper size applies the Chinese National Standard (CNS) A4 specification (210 × 297 mm). (Please read the precautions on the back before filling in this Page) Order printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs-73-565621 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (7) is of great help. From the viewpoint of stably fixing S, it is preferable that the Mη-containing content is more than 0.2% by mass. Mn is an element that can increase the strength of the steel sheet. If the super strength of TS 50 P ma is required, it is more than 1.2 mass%. It is more preferably more than 1.5 mass%. Increasing the Mη content to such a degree has the great advantage of significantly improving the mechanical properties of the steel sheet, particularly the changes in the deformation age hardening properties, against changes in hot rolling conditions. However, if the amount of M η is excessive and exceeds / 2 · 0% by mass, it becomes difficult to obtain a high r 値, which is one of the important requirements of the present invention, and the ductility is significantly reduced. Therefore, the Mn is limited to 2 0 mass% or less. For applications requiring better corrosion resistance and moldability, it is desirable to limit M η to 1.7 mass% or less. P: 0.08 mass% or less P can be used as a solid-solution strengthening element of steel. From the viewpoint of increasing strength, it is preferable to contain 0.0001 mass% or more. On the other hand, if the content is too large, the steel will become brittle and the workability of the extended flange of the steel sheet will be deteriorated. In addition, P. tends to crystallize in steel, and therefore embrittlement of the welded portion will be caused by crystallization of P. Therefore, P is limited to 0. 08% by mass or less. In applications where the workability of the extension flange and the toughness of the welded part are particularly important, it is preferable to set P to 0.4% by mass or less. s: 0.02 mass% or less S exists as an intermediary in the steel sheet, and it is an element that reduces the ductility of the steel sheet and further deteriorates the corrosion resistance, so it is best to reduce the paper size as much as possible for China National Standard (CNS) A4 Specification (210X297mm) '(Please read the precautions on the back before filling this page)

-74- 565621 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 ___ B7 _V. Description of the invention (Content, the present invention limits s to 0.02% by mass or less. For applications that require good processability, S is preferably limited to 0.05% by mass or less. When excellent stretch flange processability is required, S is preferably limited to 0. 0% by mass or less. Although it is detailed The mechanism of action 尙 is unknown, but in order to make the deformation age hardenability of the steel sheet stable and maintain a high level, it is effective to reduce S to less than 0.008 mass%. A 1 ·· 0. 0 Below 2% by mass, the A 1 series can be used as a deoxidizer to improve the cleanliness of the steel and to refine the structure of the steel sheet. In the present invention, it is preferable to contain 0. 0. 01% by mass or more. In the invention, although N in the solid solution state is used as a strengthening element, an aluminum all-static steel containing A 1 in a proper range has better mechanical properties than a conventional non-static steel without A 1 added. Another On the other hand, if there is too much A 1, it will As a result, the surface state and properties of the steel sheet are deteriorated, and the N in the solid solution state is also significantly reduced, which makes it difficult to obtain the effect of the great amount of deformation age hardening which is important in the present invention. For these reasons, the system in the present invention A 1 is limited to 0. 02% by mass or less. In consideration of the stability of the material, it is more preferable to limit A 1 to 0.001 to 0.015% by mass. In addition, although the content of A1 is reduced, There is a fear of causing coarsening of crystal grains, but the present invention can prevent such problems by optimizing the content of other alloying elements and by selecting annealing conditions in the most appropriate range. N: 0.0050 ~ 0.0250 mass% N can increase the strength of the steel sheet by solid solution strengthening and deformation age hardening. (Please read the precautions on the back before filling this page)

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This paper size is applicable to the China National Standard (CNS) A4 specification (210 × 297 mm) -75- 565621 A7 B7 Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economy In addition, the present invention can ensure the required for cold-rolled products or electroplated products by containing a proper amount of N, and then adjusting the content of A 1 to a proper value, and controlling manufacturing conditions such as hot rolling conditions and annealing conditions. N, which is necessary and sufficient to smelt the molten state. In this way, the effects of solid solution strengthening and the aging hardening due to deformation and ageing (drop stress and tensile strength) can be fully exerted, and the so-called " Tensile strength of 4 4 Ο Μ Pa or more, baking hardening amount (B Η amount) of 8 〇 Μ P a or more, increase in tensile strength before and after deformation aging treatment, addition amount △ TS 4 〇 Μ P a or more " The target of the mechanical properties of the steel sheet of the present invention is 如果. If the N content is less than 0.0050 mass%, the above-mentioned effect of increasing the strength is difficult to stably appear. On the other hand, if it exceeds 0.0005 quality If it is%, the incidence of internal defects in the steel sheet will increase, and cracks in the billet material will often occur during continuous casting. Therefore, the N content is set to a range of 0.0005 to 0250 mass%. In addition, from the viewpoint of considering the stability of the material in the overall manufacturing process and improving the yield rate, it is more preferable to limit N to a range of 0. 〇〇〇〇〇 〇 〇 170 1% by mass. As long as the N content is within the scope of the present invention, there will be no adverse effect on weldability, etc. N in the solid solution state: 〇. 〇〇〇 〇% or more In order to ensure the sufficient strength of cold-rolled products , And to effectively exert the deformation age hardening derived from containing N, the solid state N (also referred to as solid solution N) in the steel plate must be at least more than 0.000 〇% ′ (Please read first (Notes on the back, please fill out this page)

This paper size applies to China's National Standards (CNS) A4 specification (210X297 mm) -76- 565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economy It is obtained by subtracting the amount of crystallization N from the total amount of N in the steel. As for the analysis method of the amount of crystallization N, the inventors have conducted a comparative review of various analysis methods, and believe that it is based on the use. The constant potential electrolytic method is the most effective method for electrolytic extraction analysis. In addition, the method for dissolving matrix iron used in the extraction analysis includes the acid decomposition method, the halogen method, and the electrolytic method. Among them, the electrolytic method does not It is most suitable to dissolve extremely unstable crystals such as carbides and nitrides, and to dissolve only the matrix iron theoretically. Therefore, as the electrolyte, an acetone-based electrolyte is used for electrolysis at a constant potential. The present invention shows that the result of the amount of crystallization N measured using the potentiostatic electrolytic method is the most corresponding to the change in the actual material. Based on the above-mentioned reasons, the present invention will use the potentiostatic electrolytic method to extract After chemically decomposing the residue, determine the amount of N in the residue, and take this result as the amount of crystallization N. In addition, in order to obtain a high B Η amount, △ TS, the solid solution N amount is more than 0 _ 0 02 0% The above is suitable, and in order to obtain a higher amount of BΗ, ATS, the amount of solid solution N is more preferably more than 0.0003%. Although the upper limit of the amount of solid solution N is not particularly limited, All N amounts remain, and the reduction in mechanical properties is also small. 0 N / A 1 (the ratio of N content to A 1 content 値): 0 · 3 or more In order to make solid N in the product state also possible Stably remains more than 0. 0 0 1 0% by mass or more, and must be limited to be strong. (Please read the precautions on the back before filling this page)

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This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -77- 565621 A7 B7 Printing by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. The combination ratio of the N content (0.005 to 0.0025 mass%) and the A1 content (0.02 mass% or less) within the composition range of the present invention is varied in a wide range. As a result of the review of the changed steel sheet, it was learned that by setting N / Al (the ratio of the N content to the A1 content 値) to: 0.3 or more, the solid solution N in the cold-rolled product and the electroplated product can be stabilized It is more than 0.0010% by mass. Therefore, N / A 1 is limited to 0.3 or more. / The present invention contains one or more of the following d ~ g groups in addition to the above composition. More than 2 groups are preferred. D group: one or two or more of Cu, Ni, Cr, Mo, totaling less than 1.0%; e group: one or two of Nb, Ti, and V. Above, total 0.1% or less; f group: including B: 0 · 0030% by mass or less; g group: Ca, REM One or two of them are totaled 〇0〇10 ~ ο · οιο%. Elements of the d group: Cu, Ni, Cr, and Mo are all elements that help to improve the strength of the steel sheet, and can be selectively used individually or according to demand. Compound addition. This effect is exhibited only when Cu: 〇 · 〇1% or more, Ni: 0. 01% or more, Cr: 0. 01% or more, and Mo: 0.01% or more. However, the content If it is too much, it will not only increase the hot rolling deformation resistance, or cause deterioration of the chemical treatment characteristics and broad surface treatment characteristics, but also cause the welded part to harden and make the welded part (please read the precautions on the back before filling this page). ·, 11

This paper size applies the Chinese national standard (CNS &gt; A4 size (2ΗΓ × 297mm) -78- 565621 A7 B7 V. Description of the invention (4 Deterioration of formability. There is also a tendency to reduce r 値. Therefore, the elements of the d group are compounded. If it is added, the total content is preferably less than 1.0%. In addition, if the content of Mo is too large and it exceeds 0.05% by mass or more, r 値 may be significantly reduced in some cases. In the present invention, if When Μ 〇 is contained, it is desirable to set it to less than 0.05% by mass. Elements of the e group: N b, T i, and V are all elements that contribute to the miniaturization and uniformity of crystal particles, and therefore can be responded to. It is necessary to selectively contain one or two of them. This effect is to include Nb: / 0 · 005% or more; Ti: 0 _ 005% or more; V: 0.5 0 5% or more will appear, but, If the content is too large, the resistance to hot rolling deformation will be increased, or the chemical treatment characteristics and the broad surface treatment characteristics will be deteriorated. Therefore, the elements of the e group are preferably less than 0.1% in total. Elements of the f group: B It is an element that has the effect of improving the hardenability of steel and can increase the fertilizer The distribution ratio of low-temperature metamorphic phases other than the iron phase can be included as necessary based on the purpose of increasing the strength of the steel. This effect must be exhibited if B is contained in an amount of more than 0.0005 mass%. However, if the content is excessive, it will decrease The deformation ability during hot rolling reduces the amount of solid solution N due to the generation of BN. Therefore, it is appropriate to limit B to 0 _ 0030% by mass or less. Elements of the g group: C a and REM belong to the control of intermediary substances Elements whose form is helpful, especially when the formability of the extended flange is required, it is better to contain the g group alone or in combination. In this case, if the total content of the g group element is less than 〇_ 〇 〇1 0% of this paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) (Please read the precautions on the back before filling this page) Order printed by the Intellectual Property Bureau of the Ministry of Economic Affairs Consumer Cooperatives -79- 565621 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 _____ B7_ __ V. Description of the invention (, the effect of controlling the form of the intermediary substance is insufficient, on the contrary, if the content exceeds If it exceeds 0 · 0 1 ％, surface defects are likely to occur. Therefore, the content of the element in the g group is preferably limited to a total of ο · ο ο 1 〇 ~ 0 · 0 1 0%. It can improve the formability of the extended flange, but it will not cause surface defects. Next, the metallographic structure of the steel sheet of the present invention will be described. The area ratio of the ferrous grain iron phase: 80% or more The cold-rolled steel sheet of the present invention is based on A steel sheet for automobiles that requires a certain degree of formability is used as a target. In order to ensure ductility, a metallographic structure with a ferrous grain iron phase area ratio of 80% or more is used. If the area ratio of the ferrous iron phase does not exceed 80%, it is difficult to ensure the necessary ductility when used as a steel sheet for automobiles that requires workability. In addition, if it is required to have better ductility, the area ratio of the iron phase of the fertilizer grains should be more than 85%. In addition, the "fertilized iron" in the present invention refers to a "polygonal ferrous iron" in a state where no deformation remains. The average grain size of the ferrous iron phase: below 10 m The average grain size in the present invention is calculated from: the number calculated from the photo of the cross-section structure by the area calculation method prescribed by AST M; and AS The larger of the nominal particle diameters obtained from the photograph of the cross-section structure (see: "Heat Treatment" 2 4 (1984), P334) by Mr. Umoto) . Although the cold-rolled steel sheet of the present invention has a predetermined amount of solidified N in the product stage, based on the results of experiments and reviews by the inventors, it is known that even the same amount of solid-fused N Steel plates may also have the Chinese Standard (CNS) A4 specification (210 × 297 mm) applicable to this paper size (please read the precautions on the back before filling out this page) A7 B7 V. Description of the invention (d) When the deformation age hardening property changes, one of the main reasons is the crystal grain size. In the metallurgical structure of the present invention, the average crystal grain size is set to at least Less than 1 0 // m, preferably 8 // m or less, can stably obtain a high B Η amount, △ T. S. The mechanism of action, although 尙 is currently unknown, can be inferred: deformation age hardening One of the reasons for the change in properties is the crystal grain size, and it is also related to the effects of partial crystallisation or crystallization of the alloy element at the boundaries of the crystal particles, processing, and heat treatment. / Therefore, in order to change In order to stabilize the aging hardening property, the average crystal grain size of the ferrous iron phase must be set to less than 10 / zm, and more preferably less than 8 // m. Therefore, in order to ensure the ductility required for automotive steel sheets, and to achieve stability Deformation and age hardening, the present invention adopts a metallurgical structure in which the iron occupies an area ratio of ferrous grains with an average crystal grain size of 10 // m or less and 80% or more. The area ratio of Asada's loose iron phase: more than 2% The cold-rolled steel sheet is based on the Asa phase, which contains an area ratio of more than 2%. As the second phase, the Asa phase, which has an area ratio of more than 2%, can achieve good ductility and greater age hardening during deformation. Although its detailed mechanism of action is unknown, it can be speculated that because of the existence of the loose iron phase in Asada, it is because the internal deformation of the pre-deformation processing before aging is extremely effective. In addition, because of the The presence of the iron phase is also very helpful to improve the aging degradation. In addition, in order to obtain a good balance of strength and ductility and a low yield ratio, the area ratio of the loose iron phase in Asada should be more than 5%. In addition, If the area ratio of martensite phase exceeds the scale of this paper applies China National Sao quasi- (CNS) A4 size (210X297 mm) (Please read the back of the precautions to fill out this page)

-81-565621 A7 B7 V. Description of the invention ((Please read the precautions on the back before filling in this page) If it is more than 20%, there will be a problem that the ductility will be reduced. Therefore, the area ratio of Asada loose iron phase is It is appropriate to set it to 2% or more, and more preferably 5% or more, but it should not exceed 20%. In addition to the above-mentioned Asada loose iron phase, _. Can also be boron iron, f-blade iron, and residual Vostian Iron exists as the second phase without causing any problems. However, in the present invention, the distribution rate of the iron phase of the fertile grains must be more than 80%, and the distribution rate of the loose iron phase of Asada must be more than 2%. The total area ratio of cast iron, toughened iron, and residual Vosstian iron is limited to less than 18% /. The cold-rolled steel sheet of the present invention having the above-mentioned composition and metallographic structure has a tensile strength (TS) exceeding Above 4 4 0 MPa, approximately 780 MPa or below, and by controlling the aggregate structure of the fertile grains and iron phases of the mother phase, a high ratio of r 値 exceeding 1 _ 2 is obtained which has excellent deformation age hardening properties. Cold rolled steel sheet. If the steel sheet has a TS less than 4 40 MPa, it cannot be used. It is widely used for structural members. If you want to expand the scope of application, the TS system should be set to 50OMPa or more. If r 値 is less than 1.2, it cannot be applied to the Ministry of Economic Affairs. Intellectual Property Bureau employees printed on stamped and molded parts of consumer cooperatives. Also, the preferred range of r 値 is 1.4 or more. In the present invention, "having excellent deformation and age hardening properties" means: After the 5% pre-deformation of the tensile deformation is performed, and the aging treatment is performed at a temperature of 170 t for 20 minutes, the deformation stress increase before and after this aging treatment (referred to as B Η; B Η = after aging treatment) The relief stress-pre-deformation stress before aging treatment) exceeds 8 OMP a. This paper size applies Chinese National Standard (CNS) A4 specifications (210 X 297 mm) -82- 565621 A7 ___B7_ V. Description of the invention ((please first Read the precautions on the reverse side and fill in this page again); and the tensile strength increase before and after the deformation aging treatment (the aforementioned pre-deformation + the aforementioned aging treatment) (referred to as △ TS; △ TS = tensile strength after aging treatment-pre-change The pre-form tensile strength) is more than 4 OM Pa. The amount of pre-deformation is an important factor when formulating the deformation age hardening property. The inventors of the present invention first determined the deformation pattern applied to the steel sheet for automobiles, and then The effect of the pre-deformation on the age hardening of the deformation was investigated, and the results were found: (1) Except for the case of deep-drawing with a large amount of deformation, the deformation stress of the aforementioned deformation pattern was mostly equivalent to a uniaxial The amount of deformation (tensile deformation) can be sorted out. (2) The actual part is about 5% higher than this equivalent to uniaxial deformation (tensile deformation). (3) The strength of the part corresponds to the strength (Y S and T S) obtained after the pre-deformation 5% deformation aging treatment. Based on the above ideas, the present invention sets the pre-deformation of the deformation aging treatment to 5% of the tensile deformation. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs ^ The traditional coating and baking conditions are: 170 ° C X 20 m i η as the standard. In addition, when a deformation amount of more than 5% is applied to a steel sheet of the present invention containing a large amount of solid solution N, hardening can be achieved even if a slower (lower temperature) treatment is performed, in other words, an aging treatment can be performed. Conditions are wider. In general, in order to obtain the hardening amount, as long as it is not softened due to excessive aging, it is advantageous to keep it at a higher temperature for a longer time. Specifically, Θ, the steel sheet of the present invention is pre-deformed, and its hardened paper size is subject to the Chinese National Standard (CNS) A4 specification (210X297 mm) '~ -83- 565621 A7 ____B7 V. Description of the invention (8) ( Please read the notes on the back before filling this page.) The lower limit of the apparent heating temperature is approximately 1000 ° c. In addition, if the heating temperature exceeds 300 ° C, the hardening will become the highest degree, not only will it show a slight softening tendency, but the phenomenon of thermal deformation and discoloration will become obvious. As for the holding time, when the heating temperature is about 200 ° C, the hardening can be achieved by holding it for about 30 seconds or more. For greater and more stable hardening, it is best to keep it for more than 60 seconds. However, if it is kept for more than 20 minutes, it will not only be unable to obtain further hardening, but will significantly reduce / lower production efficiency and be impractical. Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs Based on the above circumstances, the present invention sets the aging treatment conditions as follows: Refer to the traditional coating and baking treatment conditions: 17 0 t X 2 0 m i η for evaluation. The steel sheet system of the present invention can stably achieve a large size even under the conditions of low-temperature heating and short holding time to the extent that conventional coating baking type steel sheets cannot achieve sufficient hardening. hardening. In addition, the method of heating is not particularly limited, and it can be used not only for heating in the gas phase environment of a heating furnace used in general coating and baking processes, but also for example, electromagnetic induction heating, or using Non-oxidizing flame, laser, plasma, etc. for heating. The strength of automotive parts must be able to support complex stresses from the outside. Therefore, the strength characteristics of material steel plates are important not only in a small deformation range, but also in a large deformation range. In view of this, the inventors have formulated the amount of β Η (strength characteristics corresponding to a small deformation domain) of the steel sheet of the present invention used as a material for automobile parts to exceed 8 OMP a or more, and set ΔΤ S Amount (corresponds to the Chinese standard kneading rate (CNS) A4 (210X297 mm) corresponding to this paper scale)-"-84-565621 A7 B7____ 5. The description of the invention (the strength characteristics of the larger deformation domain) is formulated to exceed 4 〇 M P a or more; more preferably, the BH amount is set to be more than 100 MP a or more, and the ΔTS amount is set to be more than 5 OMP a or more. When the BH amount and the ATS amount are to be larger, it is only necessary to perform the aging treatment. The heating temperature may be set to a higher temperature side, and / or the holding time may be set to be longer. The steel sheet of the present invention has: after forming, it does not need to be heated and is left at room temperature for about one week. Time, the strength can be increased to achieve the advantage of 40% when fully age-hardened. In addition, the steel sheet system of the present invention is provided with "in the state where the forming process is not performed, even if it is left at room temperature for a long time. Will not happen Deterioration of efficiency (increased YS and decreased E 1 (elongation)) ”does not have the advantages of conventional steel plates. In addition, if no problems occur during actual punching, punching must be performed As a result of three months of aging hardening at room temperature before, the increase of YS is less than 3 OM Pa; the elongation is less than 2%, and the recovery of the elongation at the drop point is less than 0.2%. Also, the present invention The surface of the cold-rolled steel sheet of the present invention described above can also be subjected to electroplating or hot-dip plating without any problem. This type of electroplated or dip-coated steel sheet also exhibits the same level of TS and B as before electroplating or dip-plating. The amount of △ TS is applicable to the types of plating or dip plating: zinc electroplating; molten zinc dip plating; alloyed molten zinc dip plating; tin electroplating; chromium electroplating; nickel electroplating. The method for manufacturing a steel sheet according to the eighth invention of the present invention will be described. Basically, the steel sheet of the present invention is obtained by heating a steel billet having a composition within the above range, and then rough-rolling it to form a steel sheet for a thin sheet. Standards apply to Chinese national standards CNS) 8 4 test (210X297 mm) &quot; I-85- (Please read the precautions on the back before filling out this page) Order printed by the Intellectual Property Bureau Staff Consumer Cooperatives of the Ministry of Economic Affairs 565621 A7 B7 The steel sheets are sequentially implemented: the refining rolling is performed, and after the refining rolling is completed, the hot rolling process of cooling and coiling into the hot-rolled steel sheet is performed; the hot-rolled steel sheet is pickled and cold-rolled to make the cold-rolled steel sheet cold. Rolling process; and the cold-rolled steel sheet is subjected to box annealing and then continuous annealing of the cold-rolled steel sheet. The steel billet used in the manufacturing method of the present invention is to prevent the Huge crystallization is preferably made by the continuous casting method, but it can also be made by the block making method and the thin steel billet casting method. In addition, after the steel billet is manufactured / made, in addition to the traditional method of cooling to room temperature and then heating again, the hot sheet can be directly sent to the heating furnace for rolling without being cooled, and can be directly rolled. Feeding and rolling methods; or energy-saving processes such as direct rolling and then rolling immediately after holding the heat slightly, can be applied without any problems. In particular, when it is desired to effectively ensure N in a solid solution state, the direct feed rolling method is one of effective techniques. First, the reason for limiting the conditions of the hot rolling process will be explained. Steel billet heating temperature: 1 0 0 0 t The steel billet heating temperature is to ensure the necessary and sufficient amount of solid solution N in the initial state, and to meet the target of solid solution N amount in the product state. It is preferable to set it at 1000 ° C or more. In addition, in order to avoid the increase of the loss caused by the increase of the oxidized weight, it is advisable to set the temperature below 1280 ° C. The steel billet heated under the above conditions is rough-rolled to form a steel sheet for thin plates. In addition, the conditions for rough rolling do not need to specifically stipulate that this paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) (Please read the precautions on the back before filling this page) Order the intellectual property of the Ministry of Economic Affairs Printed by the Bureau's Consumer Cooperatives -86-565621 A7 B7 Printed by the Consumer Property Cooperatives of the Intellectual Property Bureau of the Ministry of Economy It is better to perform as short a time as possible. Next, the steel sheet for thin plates is refined and rolled to make a hot-rolled steel sheet. In addition, the present invention is located between the rough rolling and the refined rolling. The steel sheets for the thin plates are preferably joined to each other to facilitate continuous rolling. As for the joining means, a method such as a crimping method, a laser welding method, an electron beam welding method, or the like is suitable. By implementing continuous rolls The front end and / or the rear end of the steel strip coil (to-be-processed material), that is, the proportion of the abnormal parts that are prone to be out of shape will be reduced. Material) to achieve stable hot-rolling conditions over the full length and full width. This is not only effective for hot-rolled steel sheets, but also for improving the cross-sectional shape and dimensional accuracy of cold-rolled steel sheets. Even after rolling When cooling on the heat transfer platform, tension can also be applied, so that the shape of the steel plate can be maintained. Also, because continuous rolling is performed, the leading end of the steel strip coil can pass through the rolls stably. Therefore, The conventional single-roller rolling of individual thin steel sheets has become possible because of the problem of steel sheet passability or biteability. Lubrication rolling can be implemented because of the rolling load and roll surface pressure. Both are reduced, so that the life of the roll is prolonged. Also, in the present invention, it is preferable to use a sheet steel sheet edge heater that can heat the widthwise end of the sheet steel between the rough rolling and the refined rolling. And one or two types of steel sheet heaters that can heat the ends in the longitudinal direction of the steel sheet, so that the width of the steel sheet It is advisable to uniformize the temperature distribution in the longitudinal direction and the length direction. In this way (please read the precautions on the back before filling this page) This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -87- 565621 A7 __ · _B7_ V. Description of the invention (^ As a result, the material variation in the steel plate can be further reduced. Based on the consideration of the stability of the work, the steel sheet edge heater for thin plates and the steel sheet heater for thin plates (please listen first (Please read the notes on the back and fill in this page) It is advisable to use electromagnetic induction heating method. In the above steps, it is better to use the steel sheet edge heater for the thin plate to compensate the temperature difference in the width direction of the steel plate. At this time Although the heating amount varies depending on the composition of the steel, it is preferable to set the temperature distribution range in the width direction on the exit side of the refined roll to be less than about 20 ° C. Next, a steel sheet heater for a thin plate is used to compensate for the temperature difference in the longitudinal direction. The heating amount at this time is set so that the temperature at the end portion in the longitudinal direction is higher than the temperature at the center portion by about 20 ° C. The temperature printed on the exit side of the refined roll by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs: The temperature above the exit side of the refined roll exceeds 800 ° C. FDT, in order to make the metallographic structure of the steel plate uniform and fine, For: above 80 0 ° C. If the FDT is lower than 80 ° C, the metallographic structure will be different, and some of the processed structure will remain. Even after the cold rolling annealing process, the unevenness of the metallographic structure cannot be eliminated. Come down. Therefore, the risk of various problems occurring during punching is increased. The residual phenomenon of the processing organization can be avoided by setting the coiling temperature to a high temperature. However, if the winding temperature is increased, the crystal particles become coarse, and the same problem occurs. In addition, if the coiling temperature is set to a high temperature, the amount of solid solution N will be significantly reduced, and it will be difficult to obtain a tensile strength of 4 4 OM Pa or more for the target rhenium. Therefore, the temperature F DT on the exit side of the refined roll is set to be more than 800 ° C. If you want to further improve the mechanical properties, set the temperature FDT on the exit side of the refined roll to: This paper size applies the Chinese National Standard (CNS) A4 specification (210x297 mm) &quot; -88- 565621 A7 ____B7_ V. Invention Note (^ more than 8 2 0 t is better. In addition, although the upper limit of FDT is not particularly limited, if it is too high, rust skin defects will appear (please read the precautions on the back before filling in this page) ) Is increasing. Therefore, the upper limit of FDT is preferably about 100 ° C. Although cooling after refining is not particularly limited, it is based on the length and width of the steel sheet. In consideration of the uniformity of the material, the following conditions are preferably used. That is, the invention is based on refining. After the rolling is completed, cooling is started immediately (within 0.5 seconds), and the average cooling rate during cooling is set to exceed A temperature of 40 ° C / sec or more is suitable. By adopting this condition, the high temperature region in which A 1 N is precipitated can be rapidly cooled, and N in a solid state can be effectively ensured. When the time or cooling rate does not meet the above conditions, the crystal grains grow too much, not only it is difficult to achieve the miniaturization of the crystal grain size, but also the tendency to promote the precipitation of A 1 N due to the deformation energy introduced by rolling. On the other hand, the amount of solid solution N may be insufficient, and the metallographic structure tends to become non-uniform. In addition, from the viewpoint of ensuring the uniformity of material and shape, the cooling rate is suppressed to 300 ° C / sec. The following is appropriate. The coiling temperature printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs: below 80 ° C. 'As the coiling temperature CT decreases, the strength of the steel plate tends to increase. In order to ensure the tensile strength TS For a target 値 of above 40,000 MPa, it is advisable to set the CT to below 800 ° C. If the CT is below 200 ° C, the shape of the steel sheet during winding is liable to be disordered. , The risk of problems in actual work becomes higher, and the homogeneity of the material tends to decrease. Therefore, the CT is set to be higher than 2000 ° C. This paper applies Chinese national standards. Standard (CNS) A4 specifications (210X297 male thin) -89-565621 A7 printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs ______B7_ V. Description of the invention (It should be. Also, if you want better uniformity of the material, set the CT to: higher than 3 0 0 ° C or higher is preferred. CT is preferably set to: higher than 3 5 0 t: or higher. In addition, the present invention resides in refining rolling. In order to reduce the hot rolling load, lubricating rolling can also be performed. Lubrication can be performed by Rolling can achieve the effect that the shape and material of the hot-rolled steel sheet become more uniform. In addition, it is preferable that the coefficient of friction when performing lubricating rolling is set in a range of 0.25 to 0.10. In addition, the combination of lubricating rolling and continuous rolling can be used to stabilize the hot rolling operation. After the hot-rolled steel sheet having been subjected to the above-mentioned hot-rolling process, the cold-rolling process is then used to perform pickling and cold rolling to turn into a cold-rolled steel sheet. The conditions for the pickling are only those which are generally known, and need not be particularly limited. When the scale of the hot-rolled steel sheet is extremely thin, cold rolling can be performed directly without performing pickling. The conditions for cold rolling are not particularly limited as long as they are generally known conditions. In addition, from the viewpoint of ensuring the uniformity of the structure, it is preferable to set the rolling ratio of cold rolling to more than 40%. Next, the reason for limiting the conditions of the annealing process of the cold-rolled steel sheet will be explained. The cold-rolled steel sheet is again implemented: a cold-rolled steel sheet annealing process consisting of box annealing and continuous annealing. Box sealing annealing temperature: above 80 ° C above the recrystallization temperature The present invention is used for box sealing annealing of cold-rolled steel sheets to control the aggregate structure of the base material, ie, the ferrous phase. By controlling the aggregate structure of the ferrous phase and iron phase, it is possible to achieve a high r ratio of the product steel sheet. With this box annealing, the paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) &quot; -90- (Please read the precautions on the back before filling this page) K ·

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565621 A7 B7 V. Description of the invention (D), it is easy to form the aggregate structure of {1 1 1 丨, which is helpful for the steel plate of the product! If: ^ box annealing temperature does not exceed the recrystallization temperature g tongue However, recrystallization is not completed, and the aggregate structure of the ferrous phase cannot be adjusted, so that high rization cannot be achieved. On the other hand, if the box annealing is performed at a temperature exceeding 800 ° C, surface defects of the steel sheet occur. The phenomenon tends to be significant and it becomes impossible to achieve the initial purpose. In addition, the box-sealing annealing is mainly performed in an annealing gas phase containing 3 to 5% hydrogen gas. In this case, heating / cooling The speed should be under the conditions of ordinary box annealing, which is about 30 ° C / hour. In addition, the annealing gas phase can use 100% hydrogen to accelerate the heating and cooling speed. Continuous Annealing temperature: above the A ci metamorphic point (A c 3 metamorphic point-2 0 _ ° C) below the continuous annealing temperature if the A ci metamorphic point is not reached, the Asada loose iron phase cannot be formed after annealing. AC 3 abnormal point- At 20 ° C), the helpful aggregate structure originally formed by the box annealing is lost due to metamorphosis, so a product steel plate with high r 钢板 cannot be obtained. Therefore, the continuous annealing temperature is set to: A. Above the abnormal point (A c 3 abnormal point-20 ° C) is preferable. The continuous annealing temperature is maintained (maintained) based on: production efficiency, micronization of the metallographic structure, and ensuring the amount of solidified N From a viewpoint point of view, the shorter the holding (maintaining) time of the continuous annealing temperature is, the better, but based on the stability of the work, it is better to set it to 10 seconds or more. Based on the refinement and guarantee of the metallographic structure From the viewpoint of the amount of solid solution N, the continuous annealing temperature is maintained (maintained). This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) (Please read the precautions on the back before filling this page)

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Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs -91-565621 A7 B7 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs In consideration, the holding (maintaining) time of the continuous annealing temperature is preferably higher than 20 seconds. Cooling after continuous annealing: cooling is performed at a cooling rate of 10 to 3 0 ° C / second until it is lower than 5 0 0 The temperature range is up to ° C. From the viewpoint of ensuring the refinement of the metallographic structure, the formation of loose iron in Asa, and the amount of solidified N, the cooling system after uniform heating during continuous annealing is very important. 0 ° C / sec 'for continuous cooling until the temperature range is lower than 5 0. 0 t. If the / cooling rate is lower than 10 ° C / sec, it is difficult to ensure the necessary amount of Asada loose iron And a uniform and fine metallographic structure; and ensuring a sufficient amount of solid solution N. On the other hand, if the cooling rate exceeds 300 t / sec, the amount of supersaturated solid solution C increases significantly, and therefore lies in the steel sheet. Width direction The consistency of the material will be reduced. If the cooling termination temperature during cooling at a cooling rate of 10 to 300 ° C / s is higher than 50 ° C, the microstructure cannot be refined. Over-aging treatment conditions: After cooling after continuous annealing, it is then left for more than 20 seconds in a temperature range above 350 ° C below the cooling stop temperature of the cooling treatment. The present invention lies in the uniformity of continuous annealing. After the cooling of the cooling process after heating is stopped, it is also possible to implement an "over-aging treatment" that stays in a temperature range above 350 ° C below the cooling stop temperature for more than 20 seconds. By performing over-aging treatment, both It can maintain the amount of solid solution N and selectively reduce the amount of solid solution C. If the temperature range is less than 3 50 ° C, it will take a long time to reduce the amount of solid solution C, which will reduce productivity Therefore, this paper size applies the Chinese National Standard (CNS) A4 specification (21 × 297 mm) (Please read the precautions on the back before filling this page)

-92- 565621 A7 B7 V. Explanation of the invention (It is advisable to set the temperature range above 3 50 ° C. (Please read the precautions on the back before filling this page) By the temperature is 3 5 0 ° below the cooling stop temperature Retention in a temperature range above C for more than 20 seconds can reduce the amount of solid solution C and achieve a higher degree of non-aging at room temperature. Although further improvement can be achieved by extending the residence time, approximately At about 120 seconds, the effect tends to be saturated, so the residence time is preferably less than 120 seconds. To obtain a large amount of deformation age hardening, although solid solution C or solid solution N can be used Any one of them is advantageous, but if solid solution / C is used, the aging deterioration at room temperature tends to be obvious, and the applicable parts of the steel plate are limited. Therefore, if you want to produce a universal aging hardening type of deformation The steel sheet is not only required to ensure a sufficient amount of solid solution N, but it is also preferably subjected to aging treatment. In addition, when it is desired to manufacture a high-tension cold-rolled plated steel sheet having a molten coating on the surface of the high-tension cold-rolled steel sheet of the present invention, Can also be The continuous annealing performed after the box-annealing is performed using a continuous hot-dip galvanizing production line, followed by a cooling process after continuous annealing, followed by hot-dip galvanizing or alloying to produce a hot-dip galvanized steel sheet. Printed by the Intellectual Property Bureau's Consumer Cooperative Cooperative for tempering and rolling or smoothing process: the elongation is 0.2 ~ 15%. In addition, the present invention can also be implemented after the cold-rolled steel sheet annealing process for the purpose of correcting the shape and adjusting the thickness. Temper rolling or smoothing. If the total elongation during temper rolling or smoothing is less than 0.2%, the intended purpose of correcting the shape and adjusting the thickness cannot be achieved. On the other hand, if stretching If the total ratio exceeds 15%, ductility will be significantly reduced. In addition, quenched and tempered rolling and smoothing processing, although the paper size of the two applies to China National Standard (CNS) A4 (210X297 mm) -93- 565621 A7 B7 V. Description of the invention (9) The processing forms are different, but the inventors have confirmed that both of them can deform and age harden the steel sheet. There is not much difference. In addition, quenched and tempered rolling and smoothing are effective even after the electric ore treatment. For reference, the following will be explained: The steel sheet of the present invention is punched into a shape, etc. The forming conditions during the forming process and the subsequent heat treatment conditions for the strength increase. When the steel sheet of the present invention is subjected to, for example, a deep drawing process, the deformation introduced by the forming process reaches several%. ~ 10 /%. Although the amount of deformation varies depending on the molded parts, the inner panels and structural members in the automotive technology field are all deformed by 5 to 10%. Next, these molded parts are again After the heat treatment such as coating and baking treatment is performed, the steel sheet of the present invention can effectively improve the strength of the molded product after the heat treatment. In addition, in the present invention, in the laboratory, for such a method for evaluating the baking hardenability, a JIS No. 5 size tensile test piece is taken from the rolling direction, and a tensile tester is used to give a tensile strength of 10%. After deformation and heat treatment, the tensile test was performed again. In particular, when evaluating the characteristics after the heat treatment in the low temperature range, the heat treatment conditions are set to 120 ° C x 20 minutes. This test is used to evaluate the characteristics of the completed portion immediately after the punching and after the heat treatment. That is, in the present invention, the difference between the tensile strength given to the tensile deformation and heat treatment and the tensile strength of the product (Δ T S) is defined as the strength-increasing heat treatment energy. In general, if you want to increase the strength of the molded product, the paper size applies the Chinese National Standard (CNS) A4 (210X297 mm) due to the molding. &Quot; -94-(Please read the precautions on the back before filling in this Page) order

Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 A7 __ B7 V. Description of the invention (d. The amount of deformation introduced is greater, or the heat treatment temperature after processing is higher. However, if the steel sheet of the invention is If the amount of deformation is about 5 to 10% of the above, even if the heat treatment temperature after molding is lower than the traditional heat treatment temperature after molding, that is to say, even if the heat treatment temperature is lower than 2 0 C, a sufficient The strength increases. However, if the heat treatment temperature is less than 120 ° C, when the amount of deformation is low, a sufficient strength increase effect cannot be obtained. On the other hand, if the heat treatment temperature after molding exceeds 3 5 0 ° If the temperature is C, it will begin to soften. Therefore, the heat treatment temperature after molding is preferably set to about 120 to 350 ° C. In addition, there is no special regulation on the heating method, and it can be applied: hot air Heating, infrared furnace heating, warm-bath heat treatment, electric heating, high frequency heating, etc. In addition, it can also be selectively used only to improve strength [Example] In the following examples, the amount of solid solution N, microscopic structure, tensile properties, r 、 measurement, deformation age hardening, and age properties were investigated. The investigation method was (1) Investigation of the amount of solid solution N The amount of solid solution N is calculated by subtracting the amount of crystallized N from the total amount of N in the steel obtained by chemical analysis. The amount of crystallized N is calculated using the above Adopting the aforementioned paper size is applicable to China National Standard (CNS) A4 specification (210X297 mm) (Please read the precautions on the back before filling this page)

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Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs-95- 565621 A7 ___B7 _ V. The invention description (obtained by the analysis method of the constant potential electrolysis method. . For the cross section (C cross section) perpendicular to the rolling direction, the microscopic structure was taken with an optical microscope or a scanning electron microscope, and the distribution ratio of the metallurgical structure of ferrous iron and the first Types of two phases and distribution ratio of their metallographic structure (3) Crystal particle size The crystal particle size referred to in the present invention is calculated from the photo of the cross-section structure by using the area determination method prescribed by ASTM. ; And the nominal particle size obtained from the cross-section micrograph using the cutting method prescribed by AS TM (see, for example, "Heat Treatment" 24 (1984), 334 by Mayburn et al.) The larger one is selected. (4) Tensile characteristics: Take the j IS No. 5 test piece in the rolling direction from each cold-rolled annealed steel sheet, and according to JIS Z 2241, the deformation rate is 3 X 1 0 _ 3 / second stretch test , Find the yielding strength YS, tensile strength TS, and elongation E 1. (5) Deformation and age hardening This paper is applicable to Zhongguan Jiaxian (€ Gangga 4th (21 (^ 297mm)) ; &quot; -96- (Please read the notes on the back before filling this page) Order

Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 A7 _____B7 V. Description of the invention Deformation. Next, a heat treatment corresponding to a coating baking treatment at 170 ° CX 2 0 mi η was performed, and then a tensile test was performed at a deformation rate of 3 X 1 〇_ 3 / s to determine the pre-deformation / Tensile characteristics (decreased stress YSbh, tensile strength TS) after coating and baking treatment, and calculated the amount of βΗ = YSbh — YS 5%; △ TS = TS b η — TS. In addition, YS 5% is the product Deformation stress when the steel sheet is pre-deformed at 5%, YS Β Η, TS Β Η system / pre-deformation / drop stress and tensile strength after coating and baking treatment; tensile strength of TS series steel plate. (6) r 値 The JIS was measured from each of the cold-rolled and annealed steel sheets in the rolling direction (L direction), the rolling direction (D direction) at 45 °, and the rolling direction (C direction) at 90 °. Test piece No. 5. When a uniaxial tensile pre-deformation of 15% was obtained for these test pieces The width deformation and plate thickness deformation of each test piece, and from the definition formula of r 値 is the ratio of the width deformation to the plate thickness deformation 値 r = ln (w / w〇) / ln (t / t〇) Calculate r 値 in each direction (here, w 0 and t 0 are the width and thickness of the test piece before the test; w and t are the width and thickness of the test piece after the test). Reuse the next number Formula rmean = (rL + 2rD + rC) / 4 This paper size applies to China National Standard (CNS) Α4 size (210 X 297 mm) (Please read the precautions on the back before filling this page)

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Printed by the Employees 'Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs -97-565621 A7 B7 Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Printed on the invention (^ to find the average rmean 値 (here, rL is the rolling direction (L direction ) R 値; r D is r 値 in the direction of rolling direction (direction D) of 4 5 .; r C is r 値 in the direction of rolling direction (direction c). The accuracy of the test is improved. It is assumed that the volume is constant, and it is calculated by the change in the amount of extension deformation and the deformation in the width direction. (7) Aging characteristics / JIS No. 5 test pieces are taken from each cold-rolled annealed steel sheet. The test piece was subjected to an aging treatment at 50 ° CX for 200 hours, and then subjected to a tensile test. From the obtained results, the difference in the amount of undulation stretch before and after the aging treatment, 値 ΔY-E 1, was determined to evaluate Its aging characteristics at room temperature. If △ Y-E 1 is zero, it is regarded as "non-aging" and evaluated as having excellent resistance to aging at room temperature. (8) Tensile strength after molding-heat treatment After the tensile strength is from the product steel roll JIS No. 5 test piece was taken in the direction, and after giving 10% pre-deformation, the heat treatment temperature was 120 ° C and the same level of heat treatment as the traditional coating and baking, that is, 2 ° C at 170 ° C. The heat treatment was performed for 0 minutes, and then the tensile strength was measured. (9) The reduction amount of the total stretching amount caused by aging at room temperature (△ E 1) The reduction amount of the total stretching amount caused by aging at room temperature (Δ E 1) is From this paper size, the Chinese National Standard (CNS) A4 specification (210X297 mm) is applied (Please read the precautions on the back before filling this page)

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-98-565621 A7 B7 V. Description of the invention (d) JIS No. 5 test piece is taken in the rolling direction of the product steel plate, and the full tensile amount is measured; and JI .S No. 5 test taken from the rolling direction is also used. After the sheet was subjected to a normal temperature aging treatment (100 ° C X 8 hours), the full stretch amount was measured, and the difference between the two kinds of full stretch amounts was determined. [Example 1] A steel billet having the composition shown in Table 1 was prepared into a hot-rolled steel sheet having a thickness of 3 mm in accordance with the conditions shown in Table 2. Next, a cold-rolled steel sheet having a thickness of 0.7 mm was used and then used. A continuous annealing production line or a continuous annealing-alloyed hot-dip galvanizing line performs recrystallization annealing, and then performs an alloyed hot-dip galvanizing treatment, and then performs a tempering roll with a rolling rate of 1.0% to produce a cold-rolled steel sheet. And the adhesion amount per unit area: 4 5 g / m2 alloyed hot-dip galvanized steel plated on both sides. In addition, the finish rolling in hot rolling No. 3, 8 in Table 2 is completed. The temperature is below the A r 3 abnormality point, and the other numbers are more than A r 3 Table 0 shows the results of investigating the changes in tensile strength, r 値, and tensile strength after forming and heat treatment of the cold-rolled steel sheet and alloyed hot-dip galvanized steel sheet prepared in this manner. Table 3 shows the results. From Table 3, it can be seen that both the cold-rolled steel sheet and the alloyed hot-dip galvanized steel sheet of the present invention have higher r 値 and superior deformation age hardening than the comparative example. In addition, among the suitable examples, the crystal grain size If it is less than 2 0 // m, the reduction in stretching amount caused by aging at room temperature △ E 1 is also applicable to the Chinese National Standard (CNS) 8-4 specification (2! 0X297 mm) for this paper size (please first (Read the notes on the back and fill out this page)

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs-99- 565621 A7 B7 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (less than 2.0%, which is considered very small. [Example 2] Use Table 1 The steel billet of the steel symbol B shown in the above was performed under the same conditions as in No. 2 shown in Table 2, that is, the heating temperature of the steel billet: 1 1 0 ° C, and the refining rolling temperature: 90 CTC. After hot rolling, the steel strip is coiled at a coiling temperature of 550 ° C. This steel strip is cold-rolled at a rolling rate of 80%, and then recrystallized and annealed at 840 ° C. The product characteristics of the produced / cold-rolled steel sheet are: tensile strength TS = 3 6 5 MPa; r 値 = 1 · 7. From this cold-rolled steel sheet, a JIS No. 5 test piece in the rolling direction is taken. After applying a tensile deformation amount of 10% by a tensile testing machine, heat treatment was performed according to the heat treatment conditions (temperature, time) shown in Table 4, and the tensile test was performed again. Increase in tensile strength of the product before imparting the amount of deformation (TS = 3 65 M Pa) (△ τ S). As shown in Table 4, the amount of increase in strength is the higher the heat treatment temperature, or the longer the heat treatment time, the greater the increase. However, the steel sheet of the present invention has a heat treatment temperature only At a low temperature of 120 ° C and a holding time of only 2 minutes, a sufficient tensile strength improvement of 8 2 MPa can be obtained (85% or more during heat treatment of 20 minutes) It can be seen that good low-temperature and short-term heat treatment can also achieve good deformation age hardening. In addition, for the structural members of the present invention applied to automobiles, in order to obtain a stable strength increase effect, it is common There are no problems with the temperature and time for the heat treatment. Also, even for (please read the precautions on the back before filling this page),-!! This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 (Mm) -100- 565621 A7 B7 V. Description of the Invention (^ This type of cold-rolled steel sheet is hot-dip galvanized and heat-alloyed to turn it into an alloyed hot-dip galvanized steel sheet. (Please read the precautions on the back before filling this page). [Example 3] The steel billet with the composition shown in Table 6 was hot rolled according to the conditions shown in Table 7 to produce a sheet thickness: 3.5 mm hot-rolled steel sheet. These steel sheets were cold-rolled in accordance with the conditions shown in Table 7 to produce cold-rolled steel sheets with a thickness of 0.7 / mm, and then these cold-rolled steel sheets were shown in Table 7. Recrystallization annealing was performed under the conditions described above, and a part of them was subjected to hot-dip galvanizing or alloyed hot-dip galvanizing according to the conditions shown in Table 7. The solid steel N content of the obtained product steel sheet was investigated; microscopic structure; tensile properties; age hardening during deformation. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs, and the results are shown in Table 8. It can be seen from Table 8 that all the steel plates of the present invention comply with TSxr 値 2750MPa (if B and one or two or more selected from Nb, Ti, and V are added in combination, it is TSX r 値- 8 5 0 "卩 3); 6 ^ 1-8 〇 Μ Pa a; △ TS ^ 4 〇 Μ Pa a conditions, but the comparative example is that more than one of these three conditions can not achieve the present invention [Example 4] The molten steel with the composition shown in Table 9 was melted in a converter, and the steel billet was produced by continuous casting. The steel billet was heated under the conditions shown in Table 10, and this paper was used on a standard scale. China National Standard (CNS) A4 specification (210X297 mm) '~~~ -101- 565621 A7 ______B7_ 5. Description of the invention (-(Please read the precautions on the back before filling this page), then rough roll to The steel sheet for the thin plate was made, and then a hot-rolled steel sheet was produced by performing a hot-rolling process of refining rolling under conditions not shown in Table 10. In addition, the conditions of the hot-rolled refining rolling conditions were simulated and used. Processing abnormality measuring device (Fuji Radio Engineering). It is not shown in Table 10. These hot-rolled steel sheets are cold-rolled by a cold rolling process consisting of pickling and cold-rolling under the conditions shown in Table 10. Next, for these cold-rolled steel sheets, The conditions shown in Table 10 are used for continuous annealing treatment using a continuous annealing furnace. In addition, a part of it is after the annealing process of the cold-rolled steel sheet, and then quenched and tempered. Then, for the obtained steel sheet, Investigate the amount of solid solution N, microstructure, tensile properties, r 値, age hardening and ageing properties of the deformation. In addition, the steel plates No. 4 and No. 10 were immersed with molten zinc on the surface. The galvanized steel sheet was also evaluated for various characteristics. The results of the investigation are shown in Table 11. 1. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, each example of the present invention exhibits excellent ductility, and particularly high B Η amount, △ TS, and has excellent deformation age hardening; and average r 値 1.2 or higher r 的; and room temperature aging is non-aging and excellent resistance to room temperature aging. Also, No. No · 4.No The galvanized steel sheet of 10 is affected by the reduction of the width of the galvanized layer. Compared with the cold-rolled steel sheet, although the average r 値 is reduced by 0.2; the amount of elongation E 1 is reduced by 1%, but Deformation age hardening and room temperature ageing resistance are almost unchanged from those before galvanizing. In contrast, the paper size outside the scope of the present invention is applicable to the Chinese National Standard (CNS) A4 (210X297 mm) -102- 565621 A7 ______ B7 V. Description of the invention (— (Please read the notes on the back before filling out this page) Comparative example, either the ductility is deteriorated, or the amount of B 、, △ TS is less, or else the deterioration of age is obvious It cannot be said that it has all the target characteristics and cannot be said to be a steel plate with sufficient characteristics. The steel sheet No. 11 contains (:, 1, 1, ^^, ^^ / eight 1 series is not within the scope specified in the present invention, and therefore, the amount of r 値, BΗ, Δ TS, and the aging resistance at room temperature are low. In addition, the B and Nb-containing systems of the steel plate N 〇. 12 are not within the range specified by the present invention, and the iron content of the needle-shaped fertilizer particles is far lower than the range of the present invention. Therefore, the amount of rB, B. Η, △ TS, resistance to room temperature and ageing are both low. Moreover, the B-containing system of the steel plate N ο _ 1 3 is not within the preferred range specified by the present invention, and the iron content of the needle-shaped fertilizer particles is far lower than the range of the present invention. Therefore, The amount of r 値, BΗ, △ TS, and the aging resistance at room temperature are all low. Moreover, the Nb content of the steel plate N ο _ 1 4 is not within the range specified by the present invention, and the solid solution N amount is far lower than the present invention. Therefore, the deformation age hardening is low. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, the N content of the steel plate N ο · 15 is not within the preferred range specified by the present invention, and the solid N content Few, so the deformation age hardenability is low. Neither the hot-rolled conditions nor the cold-rolled steel sheet annealing conditions of the steel plate N ο · 17 ~ N 〇 2 0 Within the preferred range of the present invention, the microscopic microstructure becomes out of the scope of the present invention, the amount of B Η and △ TS decrease, the deformation aging and hardenability are reduced, and the room temperature aging resistance is also deteriorated. [Example 5] Table 1 2 The steel of the composition shown was made into a steel billet by the same method as in Example 4. This steel billet was fed into the paper standard under the conditions shown in Table 13 to the Chinese National Standard (CNS) A4 specification ( 210X29 * 7mm) '一 -103- 565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the invention (heating and rough rolling of the earth line to make a steel sheet for thin plates with a thickness of 2.5 mm. Next, a hot-rolled steel sheet is produced by using the hot rolling process of refined rolling under the conditions shown in Table 13. After rough rolling, when refined rolling is performed, it is on the entrance side of the rolling mill and will be located in the front-rear relationship. .2 5 mm-thick steel sheets are joined together by melt-compression bonding, and then continuously rolled. In addition, between the rough rolling and the refined rolling, induction heating Steel sheet edge heater And the steel sheet heater for the thin plate is used to adjust the temperature of the steel sheet for the thin plate. The hot-rolled steel plate thus obtained is subjected to pickling and cold rolling using a cold rolling process consisting of conditions shown in Table 13 A cold rolled steel sheet having a thickness of 1.6 mm was formed. Next, these cold rolled steel sheets were continuously annealed using a continuous annealing furnace under the conditions shown in Table 13. The cold rolled annealed steel sheets thus obtained were used in the same manner as in Examples. 4 The same investigation was performed on the amount of solid solution N, microscopic microstructure, tensile properties, r 値, deformation age hardening, and ageing properties. In addition, the width direction and length direction of each cold-rolled steel sheet were each 10 To investigate its tensile properties in order to investigate the changes in yield strength, tensile strength, and tensile strength. The results are shown in Table 14. Each example of the present invention shows excellent deformation age hardening and high r 値, and shows stable and high BΗ amount, ΔT S, and average r 値 even if manufacturing conditions are changed. In addition, it was confirmed that the example of the present invention improves the thickness accuracy and shape accuracy of the steel sheet of the product, and reduces the material variation by implementing continuous rolling and temperature adjustment of the steel sheet for the thin plate in its longitudinal direction and width direction. 1/2 degree. Also, (Please read the notes on the back before filling this page)

This paper size applies to Chinese National Standard (CNS) A4 (210X297 mm) -104- 565621 A7 B7 V. Description of the invention (such as (please read the precautions on the back before filling this page) Although the tempering roll will also be rolled The elongation ratio of 5% is changed in the range of 0.5 to 2%, and the stretch ratio of smooth rolling is changed in the range of 0 to 1%, but it does not reduce the deformation age hardening. [. Example 6] The molten steel having the composition shown in Table 15 was melted by a converter, and a steel billet was produced by a continuous casting method. This steel billet was heated under the conditions shown in Table 16 (a The parts are loaded in the state of hot steel sheet), rough-rolled to make a steel sheet for thin plate, and then, a hot-rolled steel sheet is produced by a hot rolling process in which refined rolling is performed under the conditions shown in Table 16 In addition, part of it is after rough rolling, and when refining rolling is performed, at the entrance side of the rolling mill, the steel sheets for thin plates located in a front-to-back relationship are welded together by fusion welding. And then continuous rolling._Ministry of Economy The Consumer Cooperative of the Property Bureau prints cold rolled steel plates produced by cold rolling with pickling and cold rolling under the conditions disclosed in Table 16 for the hot rolled steel plates produced. For the conditions shown in Table 16, these cold-rolled steel sheets are subjected to box annealing and subsequent continuous annealing. In addition, for some of them, after the cold-rolled steel sheet annealing process, quenched and tempered rolling is performed. In addition, also An example without box sealing annealing was performed. The annealing temperature during box sealing annealing all exceeded the recrystallization temperature. Regarding the cold-rolled annealed steel sheet produced, the amount of solid solution N, microstructure, and stretching were investigated. Characteristics, r 値 measurement, deformation age hardening, ageing characteristics. In addition, the surface of the steel plate No. 17, No. 18 is based on the paper size of Table I. The Chinese National Standard (CNS) A4 specification (210X297 mm) -105- 565621 A7 B7 V. Description of the invention (1 (fe 16) After continuous annealing, a galvanizing treatment was performed to turn the galvanized steel sheet, and various characteristics were also evaluated. The results are shown in Table 1-7. It can be seen from Table 17 that each example of the present invention exhibits excellent ductility, high B Η amount, and Δ TS, and has excellent deformation age hardening; and an average r 平均 1 _ 2 or higher r 値; and room-temperature aging i are non-aging-resistant excellent room-temperature aging resistance. In addition, the characteristics of the galvanized steel plates shown in Table 1 in the steel plate numbers N 〇 4 and Ν ο · 1 〇 /, and Compared with the same cold-rolled steel sheet, there is almost no difference in its characteristics. In contrast, the comparative examples outside the scope of the present invention have either deteriorated ductility or reduced B Η amount and △ TS, or the aging deterioration is obvious. It cannot be said that it has all the target characteristics and cannot be said to be a steel plate with sufficient characteristics. The C content and N content of the steel plate N 〇. 1 1 are not within the range specified by the present invention. Therefore, the solid solution N content and the amount of loose iron in Asada are lower than the range of the present invention. Therefore, the BΗ content and ATS are reduced. , And ΔΥ — Ε1 has increased its strength. In addition, A1, N / A1, and N systems of steel plate No. 12 are not within the range specified by the present invention, the amount of solid solution N is lower than the range of the present invention, and the average crystal grain size of the ferrous iron is higher than the range of the present invention. Therefore, the amount of B 、 and Δ TS decrease, while ΔΥ-E1 increases. In addition, neither the heating temperature nor the FDT of the steel billet of the steel plate No_13 are within the preferred ranges specified by the present invention, the amount of solid solution N and the amount of loose iron in Asada are both lower than the ranges of the present invention, and the average crystal grains of the ferrous iron are Since the diameter is higher than the range of the present invention, the amount of r 値, BΗ, and ATS are reduced. In addition, coiling after hot rolling of steel plate No.14 The paper size is applicable to Chinese National Standard (CNS) A4 (210X297 mm) (Please read the precautions on the back before filling this page)

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Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs-106-565621 A7 B7 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the invention (The temperature is not within the range specified by the present invention, and the amount of solid solution N is lower than that of the present invention. Range, the average grain size of the ferrous iron is higher than the range of the present invention, and therefore, r 値, the amount of BH, and z \ TS are all reduced. Also, the continuous annealing temperature of the steel plate N ο · 15 is not specified in the present invention. In the preferred range, Asada loose iron is not produced, and the average crystal grain size of the ferrous iron is higher than the range of the present invention. Therefore, the amount of BΗ and △ TS decrease, while △ Υ — Ε 1 increases. Moreover, the steel plate Ν ο · The 16-series is not box-annealed, and the expected aggregate structure is not developed, especially r 値 is reduced. Also, the average crystal grain size of the ferrous iron and the area ratio of Asada's loose iron are not within the scope of the present invention. [Example 7] A steel billet having the composition shown in Table 18 was prepared in the same manner as in Example 1. This steel billet was heated and roughened under the conditions shown in Table 19. Rolled to make steel sheets for sheet thickness of 30 mm Next, a hot-rolled steel sheet was prepared by using the hot-rolling process of refined rolling under the conditions shown in Table 19. After rough rolling, when refined rolling was performed on a part of it, it was on the entrance side of the rolling mill. , 30 mm thick steel sheets for thin plates located in a front-to-back relationship are joined together by melt compression bonding, and then continuously rolled. In addition, between rough rolling and refined rolling, induction is used. The steel sheet edge heaters for thin plates and the steel sheet heaters for thin plates are used to adjust the temperature of the thin steel sheets. The hot-rolled steel sheets thus prepared are subjected to pickling and the conditions shown in Table 19 are used. The cold rolling process consists of cold rolling to make the thickness (please read the precautions on the back before filling this page)

This paper size applies to China National Standard (CNS) A4 (210X297 mm) -107- 565621 Employee Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs issued A7 _B7_ V. Description of the invention (I-1.6 mm cold-rolled steel sheet. Then Next, under the conditions shown in Table 19, the cold-rolled steel sheets were box-annealed, and then continuously annealed by a continuous annealing furnace. Moreover, the annealing temperature of the box-annealing was above the recrystallization temperature. The obtained cold-rolled annealed steel sheet was examined for the amount of solid solution N, microscopic structure, tensile properties, r 値, and age hardening of the deformation in the same manner as in Example 1. The width direction and length of each cold-rolled steel sheet were also investigated. The direction is to investigate the tensile characteristics at 10 places, so as to investigate the fluctuations in the drop strength /, tensile strength, and tensile amount. In addition, the variation is based on the largest difference among all the measured values. The difference of the minimum value, for example, is expressed by 5 YS = (the maximum value of YS)-(the minimum value of YS). The results are shown in Table 20. Each example of the present invention shows excellent variation. The shape aging hardening property and high r 値 show stable and high BΗ amount, △ TS, and average r 即使 even if the manufacturing conditions are changed. Furthermore, it was confirmed that the examples of the present invention are implemented by continuous rolls. Rolling and temperature adjustment of the steel sheet for the thin plate in its longitudinal direction and width direction can improve the plate thickness accuracy and shape accuracy of the product steel plate, and reduce the material variation. [Industrial Applicability] According to the present invention, the system It can be obtained: a cold-rolled steel sheet that can maintain excellent plasticity during stamping and can effectively improve tensile strength by stamping-heat treatment. And it can be achieved: industrially produced from this cold-rolled steel sheet Electroplated galvanized steel sheet, hot-dip galvanized steel sheet and alloyed hot-dip galvanized steel The paper size is applicable to Chinese National Standard (CNS) A4 (210X297 mm) (Please read the precautions on the back before filling this page)

-108- 565621 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (1 (excellent effect of the fe board / [Simplified description of the drawing] The first circle shows the steel composition (N%-1 4 / 9 3 · N b% —14/27 · Α 1% — 14/1 1 · Β%) and a graph showing the relationship between the increase in tensile strength (△ TS) after molding. Figure 2 shows N b The graph of the relationship between the B content and the △ TS in the B and B composite addition steel. / Figure 3 shows the steel with more solid solution C (traditional steel) and the steel A with more solid solution N (the present invention (Steel), a graph comparing the difference in the degree of increase in tensile strength between post-forming heat treatments in the low temperature range. Figure 4 shows the crystal grain size d and the steel composition (N%-1 4/93 .Nb% — 14/27 · Α1% — 14/11 · B%) for the reduction in the amount of stretching (△ Ε 1) caused by aging at room temperature and the degree of increase in tensile strength after molding (△ TS) Impact graph. Figure 5 is a graph showing the relationship between TSx I * 値, BH, ZXTS and N / (Al + Nb + B). Figure 6 is a graph showing the relationship between TSx r 値, BH, ATS and B content. Graph {Please read the back of the precautions to fill out this page) · clothes set

The size of this paper is applicable to the Chinese National Standard (CNS) A4 specification (21 × 297 mm) -109- 565621 A7 _B7 V. Description of the invention (107) Wisdom Finance / 1 Bureau of the Ministry of Economy Suitable example 1 = 5-=: = 5 = 5 = 5 Comparative example 5: = 5 = 5 S ca -0. 0001 -0. 0003-0. 0001-0.-0003-0. 0003-0 · 0005 ~ 0. 0001 -0. 0011 0.0027 0. 0021 0.0259 0.0026 (1Γ Formula 4 0.0023 0.0021 0.0022 0.0035 0.0022 0.0103 0.0080 0.0041 丨 0.0269 -0.0064 — 0.0154 0.0027 Composition (mass%) CO 0. 005 0. 006 0. 005 0 . 004 0. 010 0. 005 0. 005 ιη ο ο &lt; = T 0. 005 0. 005 0. 007 0. 005 0. 009 0. 015 0.011 0.030 0.045 1 0. 009 0. 008 0. 007 0 009 0. 008 0.013 0. 009 -Q 0. 016 0.035 0.010 0.035 0. 099 0. 025 0.018 0. 025 0.055 0. 001 0. 001 0. 001 Γ—4 0. 010 0.012 0.009 0. 020! 0.011 0. 028 0.012 0. 020 0.038 0.012 0.035 0.014 pq 0. 0009 0. 0011 0. 0005 0.0015 0. 0006 1 _1 0. 0011 0. 0008 0. 0014 0. 0007 0.0008 0.0001 0.0007 G ZX cs * — · ο • -Η Ρ · '&lt; ο cn ο ο Ο ιη ο ν- ο Ο οο ο Οί rH ο? -Η ο 04 ο ο LO cq ο cq Ο • ιΗ οα »— · ο ο ο ο ψ · &lt; ο ο rH ο ο ο ΙΛ ο ο 03 ο ο ο ο ΙΛ ςο ο r—4 ο ο S ο Ο Ο Ο ο 2 0. 011 0.015 0. 009 0.021 ο.οιο! 0. 030 0. 018 0. 020 0. 002 0. 001 0. 003 0.011 ο 0. 0009 0. 0020 0. 0005 0. 0020 0. 0003 0. 0011 0. 0011 0.0005 0.0098! 0.0022 0.0260 0.0027 Pot symbol c CQ 〇 QW Ο X ΗΗ (lllg &lt; Ql! SKl ^ -l4- ^ Kr: 1s (% qN.i : 6 / ZI. 「S-% o〕 t ^. (CNr * (| empty | read ^ 51 鎞 3? \\ τΞίνοϊοοο) (% 3 · 二 / M +% IV · / ^ / M +% q2 · £ 6 / inch Ι)-^ ΝΓ ^ · (ΙΓ (Please read the precautions on the back of the M before clearing this page)

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Remarks Suitable example 5f Comparative example it AJ i S 1 △ TS (MPa) after heat treatment at 170 ° C i un ON VO ○ pi oo o &gt; io _ _ 丨 1 ...... 4 un CN iio cs oo CO CO o CO 〇ό un oo 170 ° C Backward TS (MPa) un 470 440 490 530 i 〇 \ υη vn 510 440 〇450 § Inch v〇r— &lt; 445 S a ·, m to m ^ ^ —〆〆a Su &lt; 1 l § Your r- VO Ό § ψ &quot; &lt; rH o, 丨 丨 H 〇ψ Special CN Ό cs O cn o CO Inch 120 ° C TS (MPa) 435 460 420 480! _1 520 r- v〇〇ν / Ί 490 inch 489 1 420 cn inch 〇On m. Inch inch product characteristics Δ El (%) v〇CN oo cn ψ '' 4 r- • i r- ». Inch r- CN r- CN CN inch CN r —- &lt; cn CN inch crystal grain size (β m) 〇〇C &lt; 1 pi CN inch 9 t 00 1, CO ON p '&quot; 4 CN Ol cn CN CO CN CN MD CN tn co ip! Oo — 丨 丨 _ _ 丨 &lt; m CN ON ψ 1 i CO Ό —i oo P '4 —_H CN ON &lt; —ί ON ψ 1' 4 ON -iv〇 &lt; &gt; &lt; ic ^ i, 丨 &lt; tensile strength TS (MPa) s cn un cn un cn § cn 430 460 430 〇ON CO CS υη cn 417 3 70 oo 360 〇v〇cn Steel symbol I &lt; CQ CJ Q ω Ci-, o X: &lt; cu H— &lt; 1 乂 1 —1 丨 6 CN cn OO ON o &gt; '&lt; --1 · &quot; 蟮 CN cn XT (· Please read the notes on the back before filling this page)

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The size of this paper is applicable to the Chinese National Standard (CNS) A4 this grid (210X297 mm) 1 113_ 565621 Printed by the cooperative of cooperatives of the Ministry of Economic Affairs and Intellectual Property Bureau A7 B7

V. Description of the invention 2 0.21 7, 2 0 2 5 0.080 0.19 / 7 19 19 (Please read the precautions on the back before filling this page)

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This paper scale is applicable to the Chinese National Standard (CNS) A4 specification (210X29 * 7mm) -115 — 565621 A7 B7 V. Description of the invention — Η Η «ttq-—— alloying ί 1 ^ 1 1 Oi 1 cn CN 1 I 1 OJ 1 temperature ° c 1 1 s guard 1 s inch 1 1 ο 1 ss 1 plating bath temperature ° cts ν〇s 1 o ο 々v〇S s 1 board temperature ° co inch 1 v〇v〇 inch ο inch m Ό! S υη ν〇oo \ 〇1 Cooling: cooling rate before plating ° C / s 1 ν / Ί wn cs t /; 〇X VO WO VO — 1 recrystallization of cold-rolled steel sheet 1-O o 〇 〇 〇〇〇〇〇 OO os CO s oo ο oo ^ 〇g g OO g OO 〇CO 〇〇s oo s oo o ss OO Rolling cold rolling reduction% 〇gog ν / Ί c4 oo ν〇CN CO og CN oo 〇g ο g W〇CN OO v〇CN CO 80.0 og annealing process of hot rolled steel sheet an batch 1 continuous batch : Continuous i batch batch batch 1 batch batch batch continuous 劼 m sheet temperature ° c r- o CO Ο CO OO o 55 o oo o CO g r- g r- § r- OO δ poo wn i〇ο wn突 沄 wn 异 vn ο wo 〇S wn r- O cn Rolling rate% tn ON υη On σ \ un ON un ON Ο ON υη ON SI CT \ tn sv〇sv〇g ν〇o WO v〇〇oo vn v〇S v〇〇〇gm Tear u «Ξ: -5Wc- No lubrication 1 P o 55 OO OO S oo OO oo s oo o S oo oo 55 1¾] Q po ON o ON ΟΝ 8 ON Different ON s ON o ON 8 ON 8 ON o ON § o ON teyl § § Ο i 2 s § 8 1wm4 r— ^ ogoo CN om &lt; OQ UQ cu tL, a X &lt; OQ ◦ Q: z * one CN m VO Bu OO ON o Two CN ------, 玎 ------ (. Please read the notes on the back before filling in this page) This paper method is applicable to China National Standard (CNS) A4 washing Grid (210X; 297mm) -116- 565621 A7 Explanatory note 8 谳 明 发 Λ Five employees of the Intellectual Property Bureau of the Ministry of Economic Affairs Poverty Alleviation Cooperative Society of India Prepare for Disaster Preparedness Example Example Example Example Example 1 Comparative Example 1 Comparative example Comparative example Comparative example Comparative example Comparative example Deformation and age hardening 34TS MPa «-〇ON 03 v〇cn v〇ol ol m OO 3 OO BH MPa 122 183 VO 〇 \ 133; cln cnI 152 143 c n 〇 \ OO Tensile properties before deformation and aging TSxr 値 MPa 770 899 885 885 870 j V—Ή r—H ON 896 V〇CO T—H BU 7 43 662 706 MM cs OO CN CO 〇04 OO CN C &lt; 1 ψ 1 &lt; O ψ 丨 — CN cn VO cn On cn CO TS MPa 321 391 * imv〇 »1 cn 435 4 34 | 320 405 H _ 4 cn 391 33 1 336 YS MPa 225 274 22 1 22 1 304 | 304 224 284 un &gt; — &co; 274 236 24 1 2; 0.0069 0.0089 1 0.0054 0.0049! 0.0050 | 0.0088 0.0000 0.0000 0.0070 0.0082 0.0035 0.004 1 W: &lt; DQ a Q ω Uh O tc &lt; OQ oa 〇Z — CN cn mv〇OO ON 〇l _ t CN The paper size is suitable for China National Standard (CNS) Α4 size (210X297 mm) — 117 — JLd -----—, 玎 ----- -Λν. (Please read the precautions on the back before filling in this page) 565621 A7

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The size of this paper is applicable to the Chinese National Standard (CNS) A4 Ligue (210X 297 mm) · 124 565621 A7 B7 V. Invention Description (122 ^ Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs

Tempering roll factory car 1 1 .- CS in LO ΙΛ O m 〇LO 〇LO ο ο ο ο ο ο ο m ο ιη ο ♦ ♦ Summer aftermath «* Viewing the aging of cold-rolled steel sheet annealing process aging 1〇 ^ title tn 3b §3 IIIIIIIS 1 1 1 1 1 1 1 1 1 1 m m0 ο ca o OJ o ci S CsJ 〇O s 〇O? S oa o ΙΛ CS ο LO ο o C ^ 3 〇 · ΙΛ ο LO ο LO CN s ο in Cooling speed X: / sms LO Ln m in Yeah in ΙΛ S g LO inch s ΙΛ ΟΟ? LD CO ο § Hold time s Another UD ΙΩ LO CO S in LO CM un CN U3 Cvi m CO ΙΛ η ΙΛ CTi CM ΙΛ CO § η O 〇2 o oo o GO O 00 〇 卜 § oo o cn oo o oo 〇o ο οο O s ο CO 沄 00 〇! Οο ΙΟΙ Ο &lt; Μ ΟΟ Ο OQ o S mm; | § ρ o bu § &lt; £ D oo § Γ- ooooo o ooo ο ο o 卜 Ο ο ο ο ο ο 1 Ο Ψ-'Μ i i o CQ cold rolling process ~ cold steel plate Houqing oo LO 〇o o 'ooooo rH — § o UO CO ooo ο ο oo ο ο ο ο ο ο ο ο ο ο ο ο ο oo Cold gift roll:' %% CO CO s co oo CO oo CO oo oo § § CO CO oo CO ο CO oo CO 03 cn οο CO οο CO 03 CO CO cn oo Hot rolling process • coiling Η 〇Plasticity 0 ρ o LO LO o CO LT3 s L〇 沄 in s LO o § o LO osg LO om inch CSO ΙΛg LO § ΙΛII ο Inch ηη ΙΛ ο C4 LO o cq LO 圧 Delayed cooling rate V tVs sss S m tn LO points in LO inch sg § SSSSS s If. o ca o in cs CO 〇0 CO o CO ο o ιη ο CO ο οα ο Οί ο cn ο CO &lt; D Refined roll I hot rolled 'plate. Thick mm o, · oo inch * oo LO 〇vd o Yifan oo — ο one o — ο — 〇 &lt; ζ &gt; ο inch · ο 〇 inch · I exit 丨 side temperature * degree * FDT ° cs oo o oo § 00 s 00 g 00 inch to 00 § 00 o cn 00 00 o ^ T · oo S οο § oo ο LO § 00 οο § οο § 00 S CO This Lin 蝈 擗 4Q · Amine Wang Beiyang died m Jun r * ai m Luneng mmm Xuan 雔 镞 * 1 ^ it ^ ± : Mi mm s In addition CO in cn ΙΛ CO ΙΩ cn ιη cn ΙΛ CO ιη CO | Steel β plate heating temperature S RT * C o 04% s CNi rH o oo — o cn • ^ H! § O 00 r— 1 o 2 S ο ο CNJ osf— ^ S σι ο οα r—4 § · — &lt; 1—4 ο r—4 § r-Η rH §? &Quot; Η rH &lt; &lt; ffl 〇QW U &lt; OX &lt; ί &lt; ί &lt; &lt; cq o is d 1 ^ rH (N cn l0 &lt; D 00 cn ο rH rH τΗ 0Q tH C0 rH rH ΙΩ γ-Η CO rH rH 00 rH 舄 欢 »^ § 50 ^ & fly daring boudoir »* Invitation. ^. ^ 德 得 致 ^ (:: r: LrJ ^ .sa issued STK1P0 two ^ 岖 一 &quot; Thief gl-yt: Ll; &lt; n ^^^ 袒 Γ • # 0 ^ ^ 0 «r Please read the notes before filling in this page 玎 ρ 565621 A 7 B7 V. Description of the invention Example 1 This example | This example | This example | This example This example This example This example This example This example This example This example This example This example: Comparative example Comparative example tt: Comparative example Comparative example H: Comparative example発 明 例 矣 発 明 例 'Aging resistance 4 W 1 ^ &lt; 〇〇ο ο ο ο ο ο ο ο ο ο ο 〇〇ο ο ο ο ο ο LO ΙΛ ψ' * · 4 in o L〇〇OO o 〇〇 〇 Deformation and age hardening • ATS MPa g LT &gt; αο in s ιη U5 〇ΙΛ § § CO ο in 〇cq O to 03 ιο oo Β Η * 03 SS ιη αο in 0¾ ιη CO ο ο in oo ΙΟ cn / cb cn s »-Η ΙΛ 々ΙΛ o in C4 s cs cn § Product board characteristics Tensile characteristics average 1 * 値: vH in &lt; 〇CO & &lt; × 5 &lt; 〇ΙΛ ΙΩ inch fH CO cq ri] F— 1 om LO in CO LO CO inch cn CO CO cn ιη CO in CO CO CO CO CO CO cn CO CNJ CD CN CO CO to ca m co inch CO TS MPa 〇 in LQ CO un L〇in ltd m Ln co in LD Ο VO ΙΛ σι ιη LO o in to ΙΛ CS to ο οα LO LO CO ο CO CO 〇CO cents in inches o CO xp in m in LO in BU LO LO YS MPa 〇CD CNi Ui 0¾ CN to oo 05 in cn Oi ΙΛCO ο CO Inch 1-4 CO 00 V—I CO to CS CO 1Λ CO —1 in oo 04 to oo CN LO rH c〇o LjD CO bu cn CO CTi copper plate Phase 2 of the organization j Other ◦ phases: Type m Ps 1 1 I PQ «(Xt Οη 0, 1 CL, 1 I 1 P-, Qian · S 55 ^ B cq 卜 o O ο cq ΙΛ -1 卜 in o in ol -I 卜卜 肥 粒 铁 '麴 S 卜 00 卜卜 CO O 1Λ «Λ 卜 ΙΛ CN c \ 3 LO CN &lt; M OO oo noodles% 00 CNJ cn S Cft 00 ΙΛ 00 S5 CO oo 00 oo cn CO cn oo LO cn oo rH cn cn cq cn CNJ cn Copper sheet solidification N Dong mass% 0. 0075 0. 0055 0. 0055 0. 0075 0. 0110 0. 0110 0.0095 0 · 0078 0.0086 0. 0095 0. 0003 0. 0005 0. 0009 [) .0009 3. 0010) .0020) .0060) .0055 m ^ &lt; cq o Q w Cit OX &gt; -h &lt; pq 〇Screen Να rH (N CQ LO CO bu 00 cn ο rH rH tH &lt; N ύ-Η cn rH rH LO rH co iH rrH co rH d ”糍 κιΜώ ϋιΗ«: 2 · (Please read the notes on the back before filling this page) .-lb The paper scale is applicable to the Chinese National Standard (CNS) A4 Washing (210X297 mm) -126- 565621 A7 B7 Intellectual Property Bureau of the Ministry of Economic Affairs ^ [Industrial and Consumer Cooperative Cooperative Seal 5. Disclosure of Inventions (124, PF CJ &lt; 855 · '〇 &lt; 735 Other 1 Ν / Α1 un CN Ό ,, / 0.0125 0.002 〇〇 0.001 CU cn ο CS ο ν〇〇 Chemical composition (mass 1 on 0.01 CJ 0.052 〇〇〇2: ('Please read the precautions on the back before filling this page)

Paper quasi-standard home country T universal * public 7 9 2 565621 A7 B7 V. Description of the invention (12: Ministry of Economic Affairs. Hours / 1 芍 3: Industrial consumption, cooperation, Ti goods

6 1 谳 Example of the present invention ¥ 一 ― Example of the present invention鸯 9 · ^ 〇cq ο οι 〇 Cold rolled steel sheet _ process overaging ^ e P ^ Φ cn Ο 筠 钿 ^ qm 1 1 1 continuous annealing W: -Μ Η η 〇cq ο C &lt; | 〇 Cooling speed t / s ΙΛ · mm holding time S _1 § bluntness ° C ,,, _1 § S S § Box 焼 pure 焼 blunt temperature 〇〇- 〇 〇 〇1 cold rolling process .. plate thickness nun CO CO rH to — cold rolling 1 roll rate% to inch &lt; jd Χί4 1 CO hot $ Γover haw ... two 1 coiling temperature CT t: ΙΛ · tn § LO 圧 postponed cooling tn / f cncn iE Η Ρ LC ΙΛ in Inch start time Δ ts _ί CO ο CO ο CQ O: Refined rolls i Hot-rolled 11 plates: m mm LO inches · to 10 inches · Exit toilet temperature FDT * C _1 s ο s oo in LO oo Thin skin : Is there a joint with the steel sheet? The thickness of the steel sheet for the rough rolling of the sheet. Mm The steel plate heating temperature S RT * C 1180 1200 1190 5E ^ Gang plate Να ^ »4 Λ cp CN .- (Please read first Note on the back, please fill in this page) .01 and other orders Φ. I. l · Cover sheet Yong rule leather General Chinese National Standard (CNS) A4 see the standard (210X 297 Degree) "128" 565 621

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7 B V. Description of the invention (126 '1rli at the Ministry of Economic Affairs 4 ^ x-; / l * KV ^^ Ti. * P% 0 &lt; N «Inventive Example 1 Inventive Example Inventive Example Aging Resistance • 4 1 ω 1 ^ &lt; 1 ο ο Ο ATS MPa S ο 00 ο OO 辁. Η B Η * MPa ο 00 ο 00 ο OO The characteristics of the product plate i rg: s »— · w find °? Cn H: 2 &lt; 〇-3 in 〇 OO cn c〇ΙΛ CM ΙΛ Product board characteristics-«3 fH &lt; 〇rH &lt; Ό LO CO LO C0 in 1 CO ii $! TS MPa in mmm CO in U3 YS MPa m σι Ol in σ &gt; ca cn CM stencil structure second phase other i〇 phase: type u cq «« «9- S« 5 ^ M 04 CN fertilizer grain iron. particle size μ m bu bu bu surface fasten% ΙΛ 〇0 LO OO in OO Steel solid solution Ν ί 1 mass *% 0.0075 0.0075 0.0075 m ^ ss mts Να CN 1 cn l cq 癍 laid key 0: * 恋 ^ 敬 一 9 ^ 恋 谥 田 »&quot; 2 (¥ 七 啭 丨 SK 啭) &quot; &quot; THto-OQhto-SA 9 (Please read the notes on the back before filling this page)

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Claims (1)

565ί --- Announcement A8 B8 C8 D8, Patent Application 1 No. 90103293 Patent Application Chinese Application Patent Scope Amendment September 16, 1992 Amendment 1, a cold-rolled steel sheet with excellent age hardening resistance, It has the following characteristics: In terms of mass% conversion, it includes: c: 0 · 〇00〇1% or more, 0.1 5% or less; Si: 0.005% or more, 1.0% or less; Μ η: 〇1. % Or more and 2.0% or less; P: 0 · 001% or more and 0.1% or less; S ·· 0 _ 0001% or more and 0 · 02% or less; A1: 0.005% or more and 0.030% or less; N: 0.050% Above, 0.0400% or less; and N / A1 exceeds 0.30 or more, N in a solid state exceeds 0.0000% or more, and when converted to mass%, the following a group ~ d are included One or two or more of the group, group a: one or two of Cu, Ni, Cr, Mo, printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs ο: Ten groups of H-groups, with b above N ο Close one with a dagger; two times or with a kind of% 1ο • Middle 1 above V with, • 1% 5 T ο b% ο 3 ο ο ο ; The following% is 1% o TX ο ο οho to:% B 5: ο line ο group. C ο If under line 1 group ο d ο ο ο F as the remainder of the combined species, two times or the species% 1 ο Μ Ε R in the above, with% C a ο ο 6 (Please read the precautions on the back before filling this page) This paper size applies to Chinese National Standard (CNS) A4 (210 X 297 mm) Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 A8 B8 C8 D8 VI. Composition of patent application 2 and unavoidable impurities . 2. A cold-rolled steel sheet having excellent deformation age hardening properties, which is characterized by: having: in terms of mass% conversion, including: c ·· 〇. 〇〇5% or more, 〇 01% or less; Si: 〇 · 005% or more '1 · 〇% or less; Mn: 〇 · 〇1% or more and 1.5% or less; P · · 0 · 0 0 1% or more, 0 · 1% or less; S: 〇 · 〇〇〇1% Above, 0.01% or less; Α1: 0.005% or more, 0.030% or less; Ν: 0.005% or more, 0.004% or less; and N / A 1 exceeding 0.30, solid solution The state N is more than 0. 00 10%, and the rest is composed of Fe and unavoidable impurities. In terms of mass%, one or two or more of the following a group to d group are included. A group: one or two or more of Cu, Ni, Cr, and M 0, total 0.005% or more and 1.0% or less; b group: one or two of Nb, Ti, and V More than one species, a total of more than 0.005%, less than 0.1%; c lineage: B: 0.00 1% or more, 0 · 0030% or less; d lineage: one of C a, RE M or The total of the two types is more than 0.0001% and less than 0.010%. 3. For the cold-rolled steel sheet under the scope of patent application, the Chinese paper (CNS) Α4 specification (210 father 297 public ^) ~ ^, order ^ (please read the notes on the back first) (Fill in this page again.) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. Contains: B: 0.001% or more and 0.0003% or less when converted to mass%; Nb: 0.005% or more, 0.050% or less, 0.001 5 + 14/93 · ΝΙ &gt;% + 14/27 · Α 1% + 1 4/1 1 · Β% ............ (1) Formula; C% S0 · 5 · (12/93) · Νΐ3% .. ............ (2), the rest is essentially the composition of Fe. 4. For the cold-rolled steel sheet under the scope of patent application No. 1, 2 or 3, the crystal grain size of the steel sheet is less than 20 / z m. 5. For example, the cold-rolled steel sheet under the scope of patent application No. 1, 2 or 3, in which the strength improvement after forming is in the low temperature region with a heat treatment temperature of 120 to 200 ° C exceeds 6 OMP a or more . 6. A galvanized steel sheet with excellent deformation and age hardening properties, which is located on the surface of a cold-rolled steel sheet such as the scope of patent application No. 1, 2 or 3, and has: galvanized layer, molten galvanized layer and alloying Hot-dip galvanized layer. 7. A method for manufacturing a cold-rolled steel sheet with excellent deformation age hardening properties, characterized in that it will have: When converted to mass%, it includes: C: 0.005% or more and 0.01% or less; Si: 0.005% or more and 1.0% or less; Μ η: 〇. 〇1% or more, 1.5% or less; P ·· 0 _ 0 0 1% or more, 0 · 1% or less; This paper scale applies to the Chinese national ladder Standard (CNS) Α4 Specification (21〇297mm) -3-(Please read the precautions on the back before filling this page) 565621 A8 B8 C8 __ D8 _ 々, patent application scope 4 s ·· 0 · 0001% or more, 0.01% or less; A1: 0.005% or more, 0.030% or less; Ν ·· 〇 005% or more, 0.040% or less And N / Α 1 exceeds 0.30, and falls within the range defined by the following formulas (1) and (2), and contains: when converted by mass%, Β: 0.001% or more, ◦ · 0030% or less; Nb: 0.005% or more, 0.050% or less, · 0015 + 14/93 · ΝΙ)% + 14/2 7 · A 1% + 1 4/1 1 · β% ... ........ (1) Formula; C% S 〇 · 5 · (1 2/9 3) · Ν b% ............ (2) Formula 'The rest The steel sheet, which is essentially a composition of Fe, is subjected to hot rolling, and after finishing rolling, cooling is started immediately, and coiling is performed at a coiling temperature of 400 to 800 t, and then 60 to 95% After cold rolling at a rolling rate of 50%, it was recrystallized and annealed at a temperature of 650 to 900 ° C. 8 'The method for manufacturing a cold-rolled steel sheet according to item 7 of the scope of the patent application, wherein in the temperature increasing process of the recrystallization annealing treatment described above, the temperature range from 500 ° C to the recrystallization temperature is 1 to 2 The temperature was raised at a rate of 0 ° C / second. 9. The method for manufacturing a cold-rolled steel sheet according to item 7 or 8 of the scope of patent application, wherein after the above recrystallization annealing treatment, the hot-dip galvanizing treatment is performed, and then, the heat alloying treatment is performed. 10. A cold-rolled steel sheet for deep-drawing with excellent deformation age hardening is applicable to the Chinese national standard (€ milk) 8 4 specifications (210 parent 297 ^ cent): 1 4--------- -^ —— (Please read the notes on the back before filling in this card.) LINE-Printed by the Employees 'Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by the Employees' Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 A8 B8 C8 ___ D8 The range 5 plate 'is characterized by having: when converted in mass%, it includes: c ·· 0.50% or more and 0 · 0 1% or less; Si: 0.005% or more and 1.0% or less; Μη: 〇 〇ι% or more, 1.5% or less; p: 〇.01% or more, 0.1% or less; s: 0.0001% or more, 0.01% or less; A1: 0. 005% or more, 0. 030% or less; 0.005% or more and 0.040% or less; and N / a 1 exceeds 0.30 or more, N in the solid state exceeds 0.000% or more, and it is in accordance with the following formula (1), ( 2) Within the defined range, when it is converted by mass%, Β: 〇 · 0001 ～ 0.0030%; Nb: 〇〇〇〇〇5 ～ 0.050%, ^% ^ 0. 001 5 + 14/93 • Nb% + 14/2 7 · A 1% + 1 4/1 1 · B% ............ (1) Formula; C% S 〇. 5 · (12/93) N b% ............ (2) Formula 'the rest is composed of Fe and unavoidable impurities' and TSx r 値 system exceeds 750 MPa . 1 1. For example, the cold-rolled steel sheet for deep-drawing with excellent deformation age hardening properties, as described in item 10 of the scope of patent application, is in addition to the composition of the above steel, and contains: When converted by mass%, B ·· Above 0 · 〇〇01%, below 0 · 0030%; Nb: Above 0.005%, below 0.050%; This paper size applies to China National Standard (CNS) A4 specification (210X297 mm) 5 ---- ----- ^ ------ 1T ------- line (please read the precautions on the back before filling out this page) Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 A8 B8 C8 D8 Six, patent application scope 6 Ti: 0.005% or more and 0.070% or less; V: 0.005% or more and 0.10% or less; one or two or more of them, and N / (A1 + Nb + Ti + V + B) exceeds Above 0 · 30, N in the solid solution state exceeds 0 · 0 0 1 0%, and the rest is composed of Fe and unavoidable impurities, and the TSX r 値 system exceeds 750 MPa. 1 2. A method for manufacturing a cold-rolled steel sheet for deep-drawing with excellent deformation and age hardening characteristics, which is characterized by: In terms of mass% conversion, it includes: c: 0.005% or more and 0.01% or less; Si: 0.005% or more and 1.0% or less; Mn: 0.01% or more and 1.5% or less; P: 0.001% or more and 0.1% or less; S: 0.000% or more and 0.01% or less; A1: 0.005% Above, 0.030% or less; N: 0.005% or more, 0 · 040% or less; and include: B: 0 · 0001% or more, 0 · 0030% or less; Nb: 0.005% or more, 0.050% or less Ti: 0.005% or more and 0.070% or less; V: 0.005% or more and 0.10% or less; one or two or more of which are applicable to the Chinese National Standard (CNS) A4 specification (210X297 cm) ) 7 ^ 1 --------- ^ ------, 玎 ------ (Please read the notes on the back before filling this page) 565621 A8 B8 C8 D8 Intellectual Property of the Ministry of Economic Affairs Printed by the Bureau's Consumer Cooperatives 6. The scope of patent application 7 1 I and N / (A 1 + N b + Ti + V + B) exceeds CM over 0.3 3 0 1 1 ， Heating to; After exceeding 9 5 0 ° c 3 Set the temperature at the end of rolling with the rough roll 1 1 Set the temperature below 1 0 C) CTC and the temperature higher than AI '3, please perform rough roll within 1 1 range, then It is lower than L1 Γ 3 and higher than 600. It is lubricated and rolled in the temperature range of 1 1 ° C before reading. The rolling is carried out from the back of 1 I 1 • Overall rolling from rough rolling to the finish of i-rolling. Note 1 The I ratio is set to more than 80%, and the hot rolled steel sheet 1 obtained is subjected to recrystallization and recrystallization. 1 1 I fire treatment 5 next 5 Cold rolling was performed at a rolling ratio of 60 to 3: 5: 5 The cold-rolled steel sheet prepared by loading f book 1 was subjected to recrystallization annealing treatment. Page 1 1 1 3 '— A kind of cold-rolled steel sheet with excellent formability, age hardening resistance and 1 I room temperature age resistance, characterized by: Preparation 1 I has: When converted to mass%, consists of: 1 Order C: 0. 0 〇1 5% or more, 0. 02 5% or less J 1 1 S i: 0 · 〇0 1% or more, 1.0% or less 1 1 Μ η: 0 · 1% or more, 2 0% or less 9 1 j P; 0. 0% or more, 0.1% or less &gt; line IS; 0.0 0% or more and 0. 2% or less 1 1 IA 1: 0 · 〇0 1 % Or more, 0. 0 2% or less 1 1 N ·· 0. 0 0 5 0% or more, 0. 0 2 50 0% or less 9 1 I and contains: 1 IB: 0. 0 0 0 1% or more, 0 .0 0 5 0% or less &gt; 1 1 N b: 0 · 0 0 2% or more, 0. 0 5 0% or less 1 1 or two or more of 1 1, 1 1 and N / A 1 Above 0 · 3 0 and above, N in solid solution state exceeds 1 1 1 Standard (CNS) A4 specification (2IOX297 mm) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 A8 B8 C8 _ D8 6. The scope of patent application is more than 80% and the rest is composed of Fe and unavoidable impurities, and has: A metallurgical structure composed of acicular fertile iron phases with a rate of more than 5% and ferrous granular iron phases with an average crystal grain size of less than 20 # m; and its r 値 system exceeds 1.2. 14. The cold-rolled steel sheet according to item 13 of the scope of patent application, which is in addition to the above composition and when converted by mass%, includes one or more of the following groups a to c, a Groups: one or two or more of Cu, Ni, Cr, and Mo, totaling 0.01% or more and 1.0% or less; b group: one or two or more of Ti, V, A total of 0.005% or more and 0.1% or less; C lineage: one or two of Ca and RE M total 0.001% or more and 0. 010% or less. 1 5. A method for manufacturing a cold-rolled steel sheet having an excellent formability, deformation age hardening resistance, and room temperature age resistance with r 値 exceeding 1 · 2 or more. It is characterized by: It will have: Contains: C: 0.0015% or more, 0. 025% or less; Si: 0.001% or more, 1.0% or less; Μη: 0.001% or more, 2 · 0% or less; P: 0.001% or more , 0.1% or less; S: 0 · 0 0 0 1% or more, 0 · 〇 2% or less; The moth "the scale is applicable to the Chinese National Standard (CNS) Α4 specification (210X297 mm) 7〇Z 一" ^- ----- 1Τ ------ ^ (Please read the notes on the back of the threat before filling out this page) Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 565621 A8 B8 C8 _____ 08 VI. Scope of patent application 9 A1 : 0.001% or more, 0.002% or less; N: 0 · 0050% or more, 〇 0250% or less; and containing: B: 0 · 0001% or more, 0 · 00 50% or less; Nb: 002% One or two or more of the above, 0. 050% or less, and a steel blank with an N / A 1 of 0.30 or more is heated until The heating temperature of the blank is higher than 1000t: above, and rough rolling is performed to make a steel sheet for thin plates. The steel sheet for thin plates is sequentially implemented: The temperature on the exit side of the refined roll exceeds 80 ° 0 t of refined rolling; and a hot rolling process of coiling at a coiling temperature lower than 800 ° C to make a hot-rolled steel sheet; and pickling and cold-rolling the hot-rolled steel sheet to make Cold rolling process of cold-rolled steel sheet; and continuous annealing treatment of the cold-rolled steel sheet in a temperature range in which the dual phase of the ferrous iron / vostian iron coexists; and implemented: 10 to 300 ° c / sec Annealing process to cool the cold-rolled steel sheet to a temperature range lower than 500 ° C. 16. The method for manufacturing a cold-rolled steel sheet such as the item 15 of the patent application scope, which is based on the above composition In addition, when converted by mass%, one or two or more of the following groups a to c are included, and the a group: one or two of Cu, Ni, Cr, and M0. Paper size is applicable to China National Standards (CNS) Α4 (21 οχ 297 mm) TgT ^ ----- -1T ------ ^ (Please read the notes on the back before filling out this page) 565621 A8 B8 C8 D8 Patent Application Scope 10 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs, b 0. 0 c 0. 0 1 and room temperature with CS ΜΡ s AN and 0. 0 d group ~ d or more, total 0.01% or more, 1.0% or less; group: one or two or more of Ti, v, total More than 0.5% and less than 0.1%; Families: one or two of Ca and REM total more than 010% and less than 0.010%. 7. A high-tensile cold-rolled steel sheet with high r 値 and excellent deformation age hardening and non-aging properties, characterized by: having: when converted in mass%, including: 0.025% or more, 0.15 % Or less; 1: 0.005% or more and 1.0% or less; η: 0 · 2% or more and 2.0% or less;: 0.001% or more and 0 · 08% or less;: 0 · 0001% or more and 0.02% or less ; 1: 0. 001% or more, 0 · 02% or less;: 0 · 0050% or more, 0 · 0250% or less; N / A 1 exceeds 0 · 3 0 or more, and N in solid solution state exceeds 0 1 0% or more In mass% conversion, it also includes one or two or more of the following g groups, and the lineage: one or both of Cu, Ni, Cr, and M0, totaling 0.0005% or more. 1.0% or less; e lineage: one or two or more of N b, T i, V ′, total 0. 05% or more and 0. 1% or less; f lineage: B: 0 · 0005 Above%, below 〇〇〇30%; Please read the precautions before reading the gutter. The paper size is applicable to China National Standard (CNS) A4 (2 丨 〇297mm) -10- Ministry of Economic Affairs Printed by the Intellectual Property Bureau's Employee Cooperatives 565621 A8 B8 C8 D8 ----------------- 丨 丨 丨 VI. Patent application scope g Group: C a, RE Μ One or two kinds in total: 0.000% or more and 0.0010% or less, and the balance is composed of Fe and unavoidable impurities, and has an average crystal grain size including an area ratio exceeding 80% The ferrous grain iron phase smaller than 10 // m, and the metallographic structure of the Asada loose iron phase with an area ratio of more than 2% as the second phase; and its r 値 system exceeds 1.2 or more. 18. A method for manufacturing a high-tensile cold-rolled steel sheet having a high r 値 of r · exceeding 1.2 or higher and excellent deformation age hardening and non-aging properties at room temperature, characterized by: At the time, it includes: C: 0.025% or more and 0.15% or less; Si: 0.005% or more and 1.0% or less; Mn: 〇2% or more and 2.0% or less; P: 0.001% or more, 0 _ 08% or less; S: 0. 0001% or more, 0.02% or less; Al: 〇. 〇〇1% or more, 0.02% or less; ν: 〇.〇005 ％ 〇1, 〇. 250% &amp;Τ; When N / Α1 exceeds 0.30 or more, when converted by mass%, it also includes one or two or more groups of the following d group to g group to heat the steel blank, and the d group : One or two or more of Cu, Ni, Cr, and Mo, totaling 0.0005% or more and 1.0% or less; e group: one or more of Nb, Ti, and V More than two kinds, combined --------- ^ ------ 1T ------ ^ (Please read the precautions on the back before filling this page) This paper size is applicable to China's national standard (Qsjs) A4 is now (210X297 mm) -11 -565621 A8 B8 C8 _ D8 VI. The scope of patent application is 12 above 0.005% and below 0.1%; ί: B: above 0.005%, below 0. 003 0%; g: C a. One or two of REM totals: 0. 0 0 1 0% or more and 0. 0 1 0% or less until the heating temperature of the steel blank is higher than 1 000 t, and rough rolling is performed to Made of steel sheets for thin plates; The sequential implementation of the steel sheets for thin plates: refined rolling at a temperature of more than 800 ° C on the exit side of the refined roll; and coiling temperature below 800 ° C A hot rolling process of coiling to make a hot rolled steel sheet; and a cold rolling process of pickling the hot rolled steel sheet and cold rolling to make a cold rolled steel sheet; And within the range of annealing temperature below 8000t, the box-box annealing treatment is performed; and then, the annealing temperature from A c 1 metamorphic point to (A c 3 metamorphic point-20.0. Continuous annealing treatment; and then 'cooling at a cooling rate of 1 0 to 3 0 0 C / sec until less than 5 0 0 Annealing process of cold-rolled steel sheet up to the temperature range of C. 19. The method for manufacturing a high-tensile cold-rolled steel sheet according to item 18 of the patent application scope, wherein after the continuous annealing treatment described above, the method is implemented: at a temperature lower than the cooling stop temperature of the cooling treatment and higher than 3 50 ° C Over-aging treatment that stays in the temperature domain for more than 20 seconds. This paper size is applicable to China National Standards (CNS) Α4 (210 × 297 mm) ^-(Please read the precautions on the back before filling out this page), printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, 1T-12 -