TW200521249A - Cold rolled steel sheet having aging resistance and superior formability, and method of manufacturing the same - Google Patents

Abstract

A cold rolled steel sheet, and a method of manufacturing the same, designed to have aging resistance and excellent formability suitable for use in automobile bodies, electronic appliances, and the like. The cold rolled steel sheet comprises 0.003 % or less of C, 0.003 to 0.03 % of S, 0.01 to 0.1 % of Al, 0.02 % or less of N, 0.2 % or less of P, at least one of 0.03 to 0.2 % of Mn and 0.005 to 0.2 % of Cu, and a balance of Fe and other unavoidable impurities in terms of weight%. When the steel sheet comprises one of Mn and Cu, the composition of Mn, Cu, and S satisfies at least one relationship: 0.58*Mn/S ≤ 10 and 1 ≤ 0.5*Cu/S ≤ 10, and when the steel sheet comprises both Mn and Cu, the composition of Mn, Cu, and S satisfies the relationship: Mn+Cu ≤ 0.3 and 2 ≤ 0.5*(Mn+Cu)/S ≤ 20. Participates of MnS, CuS, and (Mn, Cu)S have an average size of 0.2μm or less. Since carbon content in a solid solution state in a crystal grain is controlled by fine precipitates of MnS, CuS, or (Mn, Cu)S, the steel sheet has enhanced aging resistance and formability, and has excellent yield strength and strength-ductility.

Description

200521249 IX. Description of the invention: [Technical field to which the sun and moon belong] Field of the invention The present invention relates to cold-rolled steel sheets mainly applicable to automobile bodies, electronic machinery, and the like. More specifically, the present invention is related to the Yixing Steel Sheets' system, which improves its aging resistance and shaping by using a fine sinker; a key value for controlling the carbon content in the solid solution state of the crystal grains. Properties' and a method for manufacturing the cold rolled steel sheet. 10 15 [Prior art] Background of the invention The anti-aging property is a cold-dry steel sheet for automobile body, electronic machinery and materials. It is required for the appearance of air sheet, as well as its high strength and plasticity. . "Transformation" refers to the phenomenon of tension aging that has become α Θ "old. Success", that is, the so-called "j force" is the hardening of the straw when solid solution elements such as carbon and nitrogen: to make. (3) It is fixed to the cold-aging property by sealing the box through aluminum-killed steel. In the absence of a reduction in productivity, annealing requires an extended annealing time. Therefore, the physical properties of the steel sheet caused by Γ =, extremely low carbon and nitrogen (inters 1 free, ^ 1) The eight series is made by adding enhanced carbides or nitriding 4 y elements, such as · # 4, > Do, Form, Titanium or Niobium, followed by continuous annealing. In order to produce this extremely low carbon nitrogen steel, it must be added Reinforced nitride, M 4 1… one compound or ~, such as titanium or niobium. In this regard, since these elements can increase the recrystallization temperature, the continuous annealing must be performed at a high temperature. As a result, This method for manufacturing the extremely low carbon nitrogen steel caused a decrease in productivity and increased manufacturing costs due to a large amount of energy consumption, as well as serious environmental problems. In addition, the high temperature annealing uniquely caused various defects, such as: 5 broken Cracking, deformation and the like. Moreover, because titanium or niobium has an enhanced oxidizing property, these elements generate a large number of non-metallic inclusions, causing surface defects on the steel sheet. In addition, extremely low carbon nitrogen steel tools The brittle grain boundary that caused the steel sheet to become brittle after it was formed, and is therefore considered to be a so-called "secondary work product embrittlement." To prevent the secondary work product from embrittlement, the inclusion package 10 contains Element of boron. At the same time, in the case of using the ultra-low carbon nitrogen steel in the surface treatment of products such as plating, coating or the like, many defects typically occur on the surface of these products. In order to solve For these problems, steels containing no titanium or niobium have been proposed. For example, Japanese Patent Laid-Open Nos. 6-093376, 6-093377, and 6-212354 disclose 15 Luyi uses precise control of carbon content to 0.0001-0.0015 wt% Method for improving the aging resistance of steel sheet, in which boron is added in the range of 0.0001 to 0.003 wt% to replace titanium or niobium. According to these disclosures, because the aging resistance cannot be sufficiently ensured, the steel is annealed. Thereafter, quenching is required to ensure the aging resistance. However, in this example, there is a problem that quenching is usually performed in a water bath 20 in a water bath, and an oxide coating is generated on the steel sheet, and So with pickling The oxide coating is removed, so surface defects are caused on the steel sheet, and additional manufacturing costs are also required. In addition, the steel sheet has poor in-plane anisotropy, and wrinkles are generated on the steel sheet. 7) This method encounters > Xiao consumption of Dazhi material. 200521249 At the same time, the inventors of the present invention have proposed an excellent stretch moldability without titanium or niobium and an improved extension. A method for manufacturing a cold-rolled steel sheet that is flexible is disclosed in Korean Patent Publication No. 2000-0039137. The method includes the following steps: hot-rolling a 5 steel plate at an Ar3 transformation temperature or higher, to provide a hot-rolled steel Sheet material, as measured by weight percentage, the steel sheet contains: 0.0005 to 0.002% carbon, 0.05 to 0.03% manganese, 0.015% or less phosphorus, 0.001 to 0.08% aluminum, o.ooi to 0.005 % Of nitrogen, iron and other unavoidable impurities, among which the composition of carbon, nitrogen, sulfur and phosphorus satisfies the relationship: carbon + nitrogen + sulfur + phosphorus ^ 0.025%; at 750. (: Or crimp the steel sheet at a temperature below 750 10 ° C; cold-roll the rolled steel sheet at a reduction rate of 50 to 90%; and at a temperature of 650 to 850. (: The cold-rolled steel sheet is continuously annealed at a temperature of 10 seconds or more. The cold-rolled steel sheet produced by this method has excellent ductility while ensuring the aging resistance. However, according to the disclosed method, the carbon Content, nitrogen content, sulfur content 15 and phosphorus content must be controlled to satisfy the relationship of carbon + nitrogen + sulfur + phosphorus $ 0.025% in the cold rolled steel sheet, then it must strengthen the desulfurization ability and Scaling ability, therefore, causes problems in terms of production capacity and manufacturing cost. Considering physical properties, because the equivalent strength of the final manufactured steel sheet is extremely low, it must use a relatively thick material. This In addition, when processing, there is a problem in that: due to an extremely high in-plane anisotropy index (Δ〇, excessive wrinkles are generated on the steel sheet, causing the steel sheet to crack. The present invention The inventors also proposed a manufacturing of a cold rolled steel sheet A method that can improve the 200521249 equal strength of the high strength steel with a 340 MPa grade-tensile strength is disclosed in Korean Patent Publication No. 2002-0049667. The method includes the following steps: Deformation temperature or higher-steel sheet to provide-hot-dried steel sheet, the steel sheet contains .0.0005 to 0.003% carbon, 0.001% or less, and 5%. ~ 0.02% sulfur, 0.03 ~ 〇07% lin, 0.001 ~ 〇 ″% _, 〇0055 0 /. Or less nitrogen and 0.05 ~ 03% copper, of which The copper / sulfur atomic ratio is 10 'and the reduction rate of 50 90/0 is cold. The rolled steel sheet is continuously annealed at a temperature of 700-88 generations. Cold milk steel sheet _, to 5 minutes. The cold-rolled steel sheet produced by this method has an improved equivalent strength of -24 MPa in a 340,000 MPa-high tensile strength steel. However, because the aging index of the steel sheet is greater than 30, it is not possible to ensure the aging resistance of the steel sheet, and because of the plasticity-anisotropy of the steel sheet at the M level In terms of the index (rm), it has a high in-plane anisotropy index of _0.5 or more (△ 0, which generates too many enemy folds on the steel sheet, causing the fracture of the steel 15 sheet. At the same time, a The cold-rolled steel sheet is known in the art 'It is a high-strength cold-rolled steel sheet with the same anti-aging property, and it is added by adding 0.3 ~ 0.7造 ， # Find carbon injection to increase the content of scales. The pure slab has-ductility ~ brittleness_brittleness transition temperature ', that is, the cold-rolled knitting material has poor secondary readability and embrittlement at room temperature. Causes rupture during collision. [Summary of the Invention] Summary of the Invention 20 200521249 Therefore, the present invention is made in view of the above problems, and an object of the present invention is to provide a cold-rolled steel sheet having improved moldability and aging resistance without adding titanium or niobium. And a method for manufacturing the cold-rolled steel sheet. Another object of the present invention is to provide a plasticity with excellent equivalent strength, strength -5 ductility balance characteristics, resistance to embrittlement of secondary work products, and low-plane anisotropy at a predetermined level or higher- Anisotropic index cold rolled steel sheet, and method for manufacturing the cold rolled steel sheet. According to the present invention, the above and other objects can be accomplished by providing a cold-rolled steel sheet. The cold-rolled steel sheet includes: 0.003 10 ° / in terms of weight percentage. Or less carbon, 0.003 ~ 0.03% sulfur, 0.01 ~ 0.1% aluminum, 0.02% or less nitrogen, 0.02% or less phosphorus, 0.03 ~ 0.2% manganese and 0.005 ~ 0.2% copper At least one, and iron and other unavoidable impurities that are balanced, wherein when the steel sheet contains one of manganese and copper, the composition of manganese, copper and sulfur satisfies one of the following relations: 0.58 * manganese / sulfur S10 and 15 1 ^ 0.5 * copper / sulfur < 10, and when the steel sheet contains both manganese and copper, the composition of manganese, copper and sulfur satisfies the relationship: manganese + copper S0.3 and 2 < 0.5 * ( Manganese + copper) / sulfur S20, and the precipitates MnS, CuS, and (Mn, Cu) S have an average size of 0.2 μm or less. The cold-rolled steel sheet of the present invention can be classified according to at least one additive selected from the group consisting of 20 free manganese and copper, that is, (1) steel added with manganese alone (excluding copper, also referred to as "MnS-sink Dian Steel "), (2) steel added with copper alone (excluding manganese, also referred to as" CuS-precipitated steel "), and (3) steel added with manganese and copper (also referred to as" MnCu-precipitated steel " ), Which is described in detail below. (]) The MnS-precipitated steel contains: 0.003% 200521249 or less carbon, 0.005 to 0.03 ° / 0 sulfur, 0.01 to 0.1% aluminum, and 022 or less nitrogen in weight percent , 0.2% or less of phosphorus, 0.05 ~ 0.2% of manganese, and balanced iron and other unavoidable impurities, among which the composition of manganese and sulfur satisfies the following relationship: 0.58 * manganese / sulfur < 10 and precipitate MnS Has an average size of 0.2 μηι 5 or less. A method for manufacturing MnS-sinking steel includes the following steps: hot rolling a steel plate with an Al 3 transformation temperature or higher finishing roll to provide a _ hot rolled steel sheet, and reheating the steel plate to 110 ° After a temperature of C or higher, the steel sheet contains, in terms of weight percent, carbon: 0.003% or less, 10 15 20 0.005 to 0.003% sulfur, 0.01 to 0.1% aluminum, 0.002 % Or less nitrogen, 0.2% or less phosphorus, 0.05 to 0.20 /. Manganese, as well as iron and other unavoidable impurities, among which the composition of manganese and sulfur satisfies the following relationship: 0.58 * manganese / sulfur U0; cooling at a rate of 200 t: / min or higher. For Hai steel sheet, the cooled steel sheet is wound at a temperature of 700 C or lower, the rolled steel sheet is chilled and the cold-rolled steel sheet is continuously annealed. (2) The CuS-precipitated steel contains: 0.005 to 0.003% of carbon, 0.003 to 0.025% of sulfur, and 0.0000% to 80% of Cr, measured in weight percent. 〇2% or less of nitrogen, 0.2% or less of stone dance, 〇〇〇２. 2% of copper, and the balance of iron and other unavoidable impurities, in which the composition of copper and sulfur meet The following relationship. BG.5 * steel / sulfur training and stimulus 激 have an average size of 0] μ or more. The method of fabricating CuS-sinking steel includes the following steps: finishing rolling the hot-chain steel plate with-Ar3 transformation temperature or higher to provide -hot-rolled steel sheet #, and then reheating the steel plate to a clear or higher temperature 4 steel plates are included. Measured as a percentage of heavy directors, 〇⑼〜〇_ 〇 /. 0.003 ^ 0.025 〇 / 〇 ^ ,, 〇〇〇〇〇〇8% ^ g50〇2% ^ £ 10 200521249 less nitrogen '0.2% or less fill, 〇〇〇〜0.2 . Copper, as well as iron and other unavoidable impurities, wherein the composition of copper and carbon satisfies the following relationship: 1 ^ 0.5 * steel / sulfur ^ 10; cooling the steel sheet at a rate of -3000c / min The rolled steel sheet is rolled at a temperature of 700 ° C or lower, the rolled steel sheet is cold rolled 5 times and the cold rolled steel sheet is continuously annealed. (3) The MnCu-precipitated steel contains: 0.005 to 0.003% carbon, and 0.003 to 0.025 in terms of weight percentage. /. Sulfur, 0.001 to 0.08% aluminum, 0.02% or less nitrogen, 0.2 ° / 〇 or less filling, 〇03 ~ 〇2. /. Meng, 0.005 ~ 0.2% copper, and iron and other unavoidable impurities 10, among which the composition of Meng, copper and sulfur satisfies the following relationship: Meng + copper < 〇3 and 2 < 0 5 * (manganese + copper) / sulfur S20, and the precipitates MnS, CuS, and (Mu, Cu) S therein have an average size of 0.2 μm or less. A method for manufacturing a MnCu-precipitated steel includes the following steps: finishing rolling at an Ar3 transformation temperature or higher | hot rolling a steel sheet to provide a hot-rolled steel sheet, and reheating the steel sheet to _ 丨 丨 ⑼. After a temperature of € 15 or more, the steel sheet contains: 0.0005 to 0.003% carbon, 0.003 to 0.025% sulfur, 0.001 to 0.08% aluminum, 0.02 ° / . Or less nitrogen, 0.2% or less scale, 0.03 ~ ο "0 /. Manganese, 0.005 ~ 0.2% copper, and iron and other unavoidable impurities in balance, among which the composition of manganese, copper and sulfur satisfies the following relationship: I Men + Copper 20 S0.3 and 2 < 0 · 5 * ( Manganese + copper) / sulfur <20; cooling the steel sheet at a rate of 300 ° C / min 'to wind the cooled steel sheet at 700 ° C or lower, cold rolling the wound The steel sheet is continuously annealed. The above-mentioned cold-rolled steel sheet is preferably applied to cold-rolled steel sheets having a tensile strength of 200521249 to 240 MPa in a class of high-strength cold-rolled steel sheets having elongation and tensile strength of 340 MPa or higher. material. In an example of a 240 MPa-grade extensible cold-rolled steel sheet, the steel sheet contains 0.003% or less carbon, 0.003 to 0.003 0/0 sulfur, 0.001 to 0.1 % Of Shao '0.004% or less of nitrogen, 0.015% or less of scale, 0.03 to 5 to 0.2% of manganese and 0.005 to 0.2% of copper, and checks and balances Iron and other unavoidable impurities, measured by weight percentage, where when the steel sheet contains one of copper and copper, the composition of turtle, copper and sulfur satisfies one of the following relations: 0.58 * manganese / sulfur S10 and H5 * Copper / sulfur < 10, and when the steel sheet contains both copper and copper, the composition of tortoise, copper and sulfur satisfies the relationship of the 10-series formula ·· manganese + copper ^ 0.3 and 2 < 0 · 5 * ( Titanium + copper) / sulfur < 20, and the sinks MnS, CuS and (Mn, Cu) S have an average size of 0.2 μm or less. In an example of a 340 MPa-grade or higher high-strength cold-rolled steel sheet, it can be classified as one or both of phosphorus, silicon, and chromium (as a solid-solution strengthening element) added to the extensible cold-rolled steel sheet. The steel material of the rolled steel sheet, and the steel material of which 15 has an increased nitrogen (as a strengthening element of the sinking hall) in the extensible cold rolled steel sheet. That is, it is desirable that one or both of 0.2% or less of ytterbium, 〇1〇 $ Shi Xi, and 0.2 ~ L2% of chromium are included in the extensible steel sheet. If phosphorus is added to the extensible cold-rolled steel sheet alone, it is preferable to add 0.03 to 0.2% of phosphorus to the extensible cold-dried steel sheet. 20 places, can be used to increase the nitrogen content to 0. 005 ~ 〇 〇 2 〇 / 〇 and add power 0 ° halo 0.06% due to the structure A] N Shendian objects to ensure high strength in order to more Strengthen the plasticity of the cold-rolled steel sheet, 4 sheets are more packageable, the steel sheet contains 0.01 ~ 0.2% molybdenum, and in order to ensure its resistance to aging, it can also contain 0.01 ~ 0.2% vanadium . 12 200521249 The drawings briefly explain the above and other objects, features, and other advantages of the present invention. The following will be understood more clearly with the detailed description of the attached drawings, in which 5: Figures 1a to 1c are Graphical representation, which illustrates the change of carbon content relative to the size of a sinker in the state of a solid solution in a grain; Figures 2a and 2b are graphical representations illustrating the size of a MnS sinker relative to the cooling rate; 1 The 3rd & perfect chart is a graphical representation illustrating the size of the CuS precipitates relative to the cooling rate; and the 4a and patters are graphical representations illustrating the size of the MnS, CuS, and (Mn5Cu) S precipitates relative to the cooling rate. [Embodiment] Detailed description of the preferred embodiment The preferred embodiment of the present invention will now be described in detail. However, it is understood that the present invention is not limited to these preferred embodiments. The inventors of the present invention have discovered some new facts as described below in the study of strengthening the ageing resistance of steel sheets without adding titanium and niobium. This fact is that the fine precipitates of MnS, CuS, and (Mn, Cu) S 玎 properly control the carbon content in a solid solution state of a grain (ie, solid solution carbon), and cause enhanced anti-aging Sex. Due to the reinforcing effect of the Shen Dian, these Shen Dian objects have a positive impact on increasing the current strength ’and strengthening the strength-ductility balance characteristics as well as the in-plane anisotropy index of the steel sheet 13 200521249. As can be seen in Figure 1 as shown in Fig. 1, as the MnS, CuS & (Mn, Cu) s sinker system is distributed more finely, the content of solid solution carbon in the grains is reduced. Because the solid solution carbon existing in a grain moves relatively freely, the carbon system moves and combines with the movable dislocation, which affects the aging characteristics of the steel sheet. Therefore, when the content of the solid solution carbon in the crystal grains is reduced to a predetermined level, the aging resistance can be enhanced. Based on ensuring the aging resistance, the solid solution carbon content in a grain is at most 20 ppm or less, and preferably 15 ppm or less. No. "to. Figure 10 is a graphical representation of a steel containing 0.003% carbon, and it can be seen that when the precipitates of MnS, CuS and (Mn, Cu) S are dispersed in a size of 0 2 μΐΉ or less The content of solid solution carbon in the crystal grains is preferably controlled to 20 ppm or less. Regarding to control the content of solid solution carbon in the crystal grains to 15 ppm or less (the most suitable is beetle 15) size of the precipitate, as can be seen from Fig. 1, the precipitate of MnS has a size of about 0.2 μm or less, and the precipitate of CuS has a size of about 0 · m #claw or less And the precipitates of MnS, CuS and (Mn, Cu) S have a size of about 0 "μm or less. In this way, in order to control the solid solution carbon content in the crystal grains to be 20 ppm or less, it is important that the MnS, CuS and ( The precipitates of Mn, Cu) S are finely distributed. According to the present invention, the carbon content of fine precipitates with MnS, CuS and (Mn, Cu) S is preferably increased to 0.003 wt%, which results in a low load in a steel manufacturing method. Noting such a new fact, there is a pair of finely distributed 14 200521249

New research on methods of MnS, CuS and (Mn, Cu) S precipitates. These results show that what is needed is to control the content of manganese, copper and sulfur and the composition of these elements in the steel, and to obtain ^ fine particles by controlling the cooling rate after hot rolling. 5 Figure 2 is a graphical representation obtained after investigating the size of the condensate against the cooling rate after hot-rolling a steel sheet. The steel sheet contains 0.0018 ° / 〇 carbon, 0.15 ° Manganese / O, 0.008% Phosphorus, 0.015% Sulfur, 0.03 ° / O, and 0.0012% Nitrogen (where 0.58 * | Meng / Carbon = 5.8). Referring to FIG. 2a, it can be found that when the composition of manganese and sulfur satisfies the relationship of 10: 0.58 * manganese / sulfur &lt; 10, the MnS sinks when the cooling rate of the steel sheet is appropriately controlled. The size of the temple can be 0.2 μΐΉ or less. Figure 3a is a survey of the cooling rate after hot-rolling a steel sheet; the graphical representation obtained after the size of the precipitate shows that the steel sheet contains: 0.0018% carbon and 0.01% by weight Phosphorus, 0.008 ° / 〇 sulfur, 0.055% 15 aluminum, 0.0014% nitrogen, and 0.041% copper (where 0.5 * copper / sulfur = 2.56). Referring to Fig. 3a, it can be found that when the composition of copper and sulfur satisfies the relationship: 0.5 * copper / sulfur &lt; 10, the CuS precipitates when the cooling rate of the steel sheet is properly controlled. The size of the object may be 0.1 μm or less. Figure 4a is a graphical representation obtained after cold-rolling a steel sheet and examining the size of the sediment at a cooling rate of 20%. The steel sheet contains: 0.0025 ° / 〇 % Manganese, 0.009% phosphorus, 0.015% sulfur, 0.04% aluminum, 0.0029% nitrogen, and 0.04% copper (where manganese + copper = 0.17 and 0.5 * (manganese + Copper) / sulfur = 5.67). Referring to Figure 4a, I found that when the composition of manganese, copper and sulfur satisfies the relationship: manganese + copper] 5 200521249 and 2 ^ 0 · 5 * (junction + copper) / sulfur <20 When the cooling rate of the steel sheet is appropriately controlled, the size of the MnS, CuS, and (Mn, Cu) S precipitates may be 0.2 μm or less. The cold-rolled steel sheet of the present invention has a high equivalent strength 'and therefore allows the thickness of the steel sheet to be reduced, thereby providing the effect of reducing the weight of its product. In addition, due to its low in-plane anisotropy, wrinkles and patterns rarely occur when processing the steel sheet and after processing the steel sheet, respectively. The cold-rolled steel sheet of the present invention and the manufacturing method thereof will be described in detail below. 10 [Cold-rolled steel sheet of the present invention] Carbon (C): The carbon content is preferably 0.003 wt% or less. If the carbon content is more than 0.003 wt%, the amount of solid solution carbon in a grain increases, which makes it difficult to ensure the aging resistance of the steel, and the grains in an annealed sheet change in size. For shrinkage, therefore, the ductility of the steel is significantly reduced. More preferably, the carbon content is between 0.0005 and 0.003. The carbon content of less than 0.0005 wt% will cause the generation of coarse bond grains in a hot-rolled sheet. Therefore, the strength of the steel is reduced, but the in-plane anisotropy is increased. According to the present invention, since the liquid solution carbon in a steel material can be greatly reduced, the carbon content can be increased to 0.003 wt%. Therefore, it is possible to avoid a decarburization treatment for extremely low carbon content. The carbon content for this purpose is preferably in the range of 0.002 wt% <carbon S 0.003 wt%. Sulfur (S) The sulfur content is preferably 0.003 to 0.03 wt%. Sulfur content of less than 0.003 wt% will not only reduce the amount of MnS, CuS and 16 200521249 (Mn, Cu) S, but also cause the generation of excessively rough precipitates, thus reducing the aging resistance of the steel sheet. A sulfur content of more than 0.03 wt% results in a large amount of solid solution sulfur, and therefore significantly reduces the ductility and moldability of the steel sheet, and increases the possibility of thermal shrinkage. According to the present invention, in the example of the MnS-5 precipitated steel, the sulfur content is preferably in a range between 0.005 wt% and 0.03 wt%, and in the example of the CuS-precipitated steel, the sulfur content is preferably In the range of 0.003 wt% to 0.025 wt%. In the example of the MnCu-precipitated steel, the sulfur content is preferably in a range between 0.003 wt% and 0.025 wt%. 10 Aluminum (A1): The aluminum content is preferably 0.01 to 0.1 wt%. Aluminum is an alloying element that is commonly used as a deoxidizing agent. However, in the present invention, it is added to avoid aging caused by the solid solution nitrogen of the precipitated nitrogen in the steel. A content of less than 0.01% by weight will cause a large amount of solid solution nitrogen, thus making it difficult to avoid aging. Conversely, a content of more than 15 0.1% by weight will result in a large amount of solid solution, thus reducing the steel sheet. Ductility of wood. According to the present invention, in the examples of the CuS-sintered steel and the MnCu-precipitated steel, the aluminum content is preferably in a range between 0.01 wt% and 0.08 wt%. If the nitrogen content is increased to 0.005 to 0.02%, a high-strength steel sheet can be obtained by the reinforcing effect of the A1N precipitate. 20 Nitrogen (N): The nitrogen content is preferably 0.02 wt% or less. Nitrogen is an unavoidable element added to the steel during the manufacturing process of the steel, and in order to obtain the reinforcing effect, it is preferably added to the steel to 0.02 wt%. In order to obtain the extensible steel sheet, the nitrogen content is preferably 0.004 wt% or less. In order to obtain a high-strength steel sheet 17 200521249, the nitrogen content is preferably between 0.005 and 0.2%. Although the nitrogen content must be 0.005% or more to obtain the reinforcing effect, a nitrogen content of more than 0.02 wt% results in a deterioration in the formability of the steel sheet. In order to use nitrogen to provide a high-strength steel, the phosphorus content is preferably between 0.03 and 0.06%.

5 According to the present invention, in order to ensure high strength by the A1N precipitate, the combination of aluminum and nitrogen, that is, 0.52 * aluminum / nitrogen (whose aluminum and nitrogen are specified in wt%) is preferably 1 to In range. A combination of aluminum and nitrogen (0.52 * aluminum / nitrogen) less than 1 causes aging caused by solid solution nitrogen, and a combination of aluminum and nitrogen (0.52 * aluminum / nitrogen) more than 5 results in negligible enhancement effects. 10 Phosphorus (P): The phosphorus content is preferably 0.2 wt% or less.

Phosphorus is an alloying element, which can increase the solid solution strengthening effect, but allows a slight reduction in r-value (plasticity-anisotropy index), and can ensure the high strength of the steel in which the precipitates are controlled . Therefore, in order to ensure the high strength by using phosphorus, the phosphorus content is preferably 0.2 wt% or less. 15 Monophosphorus content greater than 0.2 wt% can lead to a reduction in ductility of the steel sheet. In order to use nitrogen to provide a high-strength steel, the phosphorus content is preferably between 0.03 and 0.06%. When phosphorus is added to the steel alone to ensure the high strength of the steel sheet, the phosphorus content is preferably between 0.03 and 0.2 wt%. For the extensible steel sheet, the phosphorus content is preferably 0.015 wt% or less. For steel sheets that ensure high strength by using A1N precipitates, the phosphorus content is preferably between 0.03 and 0.06 wt%. This is due to the fact that although a phosphorus content of 0.03 wt% or more can ensure a target strength, a phosphorus content of more than 0.06 wt% can reduce the ductility and shapeability of the steel. According to the present invention, when the high strength of the steel sheet is ensured by adding silicon and chromium, the 18 200521249 phosphorus content can be appropriately controlled to 0.2 wt% or less to obtain the target strength. According to the present invention, at least one of manganese and copper is preferably added to the steel. These elements are combined with sulfur to form [], CuS and (Mn, Cu) s precipitates. 5 (Mn) · The content of Mn is preferably between 0.03 and 0.2 wt%. Manganese Is an alloying element that precipitates the solid solution sulfur in the steel into the MnS precipitate, thereby preventing heat shrinkage caused by the solid solution sulfur. In the present invention, due to sulfur and / or a combination of copper and manganese And due to the proper conditions of the cold section rate, manganese is precipitated as fine "core and / or (Mn, Cu) s 10 precipitates", and when the aging resistance of the steel sheet is basically ensured, the steel is strengthened. Sheets play an important role in terms of equivalent strength and in-plane anisotropy. In order to achieve these effects, the manganese content must be 0.003 wt% or more. At the same time, a manganese content of more than 0.2 wt% causes rough precipitates, thereby reducing the aging resistance of the steel sheet. If manganese is added to the steel alone (that is, no copper is added), the manganese content is preferably between 0.05 and 0.2 wt%. Copper (Cu) The copper content is preferably between 0.05 and 0.02 wt%. The copper system is an alloy element that generates fine precipitates under the proper conditions of the cooling rate before the winding process during the combination of sulfur and / or manganese and during the hot rolling process, thus reducing the solids in the grains The amount of solution carbon, and 20 plays an important role in strengthening the aging resistance, in-plane anisotropy, and plastic anisotropy of the steel sheet. In order to form a fine precipitate, the copper content must be 0.005 wt% or more. If the steel content is more than 0.2 wt%, coarse precipitates are caused, and thus the aging resistance of the steel sheet is deteriorated. If copper is added to the steel alone (that is, ‘without adding fifteen’), the copper content is preferably between 0 · 〇 j ~ 19 200521249 0.2vvt0 / 〇. According to the present invention, the content and combination of ferrite, copper, and sulfur are controlled to produce fine precipitates, and they vary depending on the amount of manganese and copper added. In the example of the MnS and precipitation steel, the combination of manganese and sulfur preferably satisfies the relationship: 0.58 * manganese / sulfur ^ 10 (the fibrous and sulfur systems are specified in wt%). I and M are combined to form the MnS precipitate, which can be changed in the precipitation state according to the amount of M and M added, and thus affect the aging resistance, equivalent strength and in-plane anisotropy of the steel sheet. Sex index. The value of 0.58 * manganese / sulfur is more than 10, which results in the formation of rough MnS precipitates, which increases the aging index. Therefore, it provides poor equivalent strength and in-plane anisotropy index. In the example of the CuS-precipitated steel, the combination of copper and sulfur preferably satisfies the relationship: KO · 5 * copper / sulfur do (the copper and sulfur systems are specified in wt%). Copper Spear Stone Claw ,,,. a in order to generate 5 Hai CuS sink; the object, which can be changed in the precipitation state according to the amount of added copper and sulfur, and therefore affect the anti-aging property, the 15 plasticity-anisotropy index and the in-plane anisotropy index. A value of 0.5 * steel / sparseness causes 1 or more effective sinkers to be produced, and a value of 0.5 * steel / sulfur greater than 10 results in rough CuS sinkers, causing the aging The increase of the index provides the secret rate anisotropy margin and the anisotropy index in the plane. In order to stably ensure that the MEMS sinker is (u μmΏ or less), the value of the 〇20 copper / sulfur is preferably 1 to 3. ΒΘ / 'J,, added to the dish and copper to 5 black steel sheet The total content of Meng and copper is preferably 0.3 Wt% or less. This is attributed to the fact that the content of Meng and copper more than 0% and 3% may produce silkworms. In addition, the value of aging resistance is 0.5 (mighty + copper) / sulfur (its strength, copper and sulfur are referred to as 20%, 200521249), and it is preferably between 2 and 20. Manganese, copper and sulfur are combined to generate the MnS. , CuS and (Mn, Cu) S precipitates, which can be changed in the precipitated state depending on the amount of manganese, copper and sulfur added, and thus affect the aging resistance, the plasticity-anisotropy index and the in-plane Anisotropy index. A value of 0.5 * (manganese + copper) / sulfur of 2 or more results in effective precipitation, while a value of 0.5 * (manganese + copper) / sulfur is greater than 20 Rough deposits cause the aging index to increase, so it provides poor plasticity-anisotropy index and in-plane anisotropy index. According to the present invention, it has 0 · 5 * (manganese + copper) / sulfur Value between 2 and 20 Within this range, the average size of the precipitate is reduced to 0.2 μm or less. In this 10 example, it is desirable that the precipitate is distributed in a quantity of 2 X 106 or more. When 0.5 * ( | Meng + copper) / sulfur value starts from 7, and the type and number of precipitates change significantly. In particular, when the value of 0.5 * (Mn + copper) / sulfur is 7 or less Many very fine MnS and CuS individual sinking systems are homogeneously distributed, rather than the (Mn, Cu) S composite precipitate. At the same time, when the value of 0.5 * (violent) 5 + copper V sulfur is more than At 7 o'clock, regardless of the slight differences in the size of the temples, the number of precipitates distributed on the grains and grain boundaries is reduced due to the increase in the number of (Mn5 Cu) S composite precipitates. In the present invention , Increasing the number of the sunken objects can enhance the anti-aging resistance, the in-plane anisotropy index, and the embrittlement resistance of the secondary work product. For this purpose, the sunken objects are preferably 2X 2 0 1 〇8 or more number distribution. In the present invention, even in the case where the value of 0.5 * (fierce + copper) / sulfur is the same, adding a smaller amount of fibrous and steel can reduce the distribution The number of precipitates at the grains or grain boundaries. If the content of manganese and copper is increased, the precipitates become coarse seams, resulting in a reduction in the number of precipitates distributed at the grains or grain boundaries. 0 21 200521249 According to the present invention, the MnS, CuS And (Mn, Cu) S precipitates preferably have an average size of 0.2 μm or less. If the average size of the Mns, CuS and (Mn, Cu) S sinkers is greater than 0.2 μm, specifically , The aging index increases rapidly, and the plasticity-anisotropy index and the in-plane anisotropy 5 index become 彳 · ^ poor. According to the present invention, the preferred size of MnS is 0.2 μΐΉ or less' and The preferred size of CuS is 0 ″ μΐΉ or less. In the example where MnS, CuS, and (Mn, Cu) S sinks are mixed in the crystal grains, the size of the sinks is preferably 0.2 μm or less, and more preferably 0.1. μm or smaller. When the size of the precipitate is reduced, it is superior to anti-aging properties. 10 According to the present invention, when applied to the 340 MPa-grade or higher high-strength steel sheet, the solid solution reinforcing element may be added, for example: filling the steel sheet, that is, adding at least phosphorus, One of silicon and chromium to the steel sheet. The effect obtained by adding breaks is previously described, and will be omitted here. 15 Silicon (Si): The silicon content is preferably between 0.1 and 0.8%. Shixi is an alloy element that can increase the solid solution strengthening effect, but allows a slight reduction in ductility, and therefore ensures the high strength of the steel, in which the precipitate is controlled according to the present invention. One is 0.01% or more, and the star-containing star can ensure the strength of the steel sheet, but a silicon 20 content higher than 08% can cause its ductility to decrease. Chromium (Cr): The chromium content is preferably from 0.2 to 2; [2 to 2%. Chromium is an alloying element that can increase the strengthening effect of the solid solution. However, chromium carbide reduces the brittleness temperature of the secondary work product and the aging index, thereby ensuring high strength but reducing the anisotropy index of the steel. 22 200521249 The sanctuary is controlled in the steel according to the present invention. A chromium content of 0.2% or more can ensure the strength of the steel sheet, but a f content higher than 1.2% can cause its ductility to decrease. According to the present invention, molybdenum (Mo) and / or vanadium (V) are preferably added to the cold rolled steel sheet. Molybdenum (Mo): The molybdenum content is preferably between 0.01% and 0.2%.

Molybdenum is an alloying element which can increase the plasticity-anisotropy index of the steel sheet. A molybdenum content of 0.001% or more can increase the plasticity-anisotropy index, but a molybdenum content of more than 0.2% can cause its heat shrinkage without increasing by 10 plus its plasticity-anisotropy index. . Vanadium (V): The vanadium content is preferably between 0.00% and 0.2%. Vanadium is an alloying element that ensures aging resistance by precipitating solid solution carbon. A vanadium content of 0.01% or more can increase the aging resistance, but a vanadium content of more than 0.2% can reduce the plasticity-anisotropy index. 15 The composition of vanadium and carbon (0.25 * vanadium / carbon) satisfies the relation KO · 25 *

Vanadium / carbon ^ 20 (where vanadium and carbon are specified in wt%). A composition of vanadium and carbon less than 1 (0 · 25 * vanadium / carbon) can reduce the carbon precipitation effect of the solid solution, and a composition of vanadium and carbon more than 20 (0.25 * vanadium / carbon) can reduce the plasticity- Anisotropy index. 20 [Method of manufacturing cold-rolled steel sheet] The present invention is characterized in that the steel sheet that satisfies the above-mentioned composition is processed through hot rolling and cold rolling, and therefore, it is allowed to reduce the average size of a precipitate of a cold-rolled steel sheet. The average size of the precipitate is affected by the content and composition of manganese, copper, and sulfur, as well as the manufacturing process, and is specifically directly affected by the cooling rate after a hot rolling. Hot rolling conditions According to the present invention ', the steel material satisfying the above composition is reheated, and then a hot milking procedure is performed. The reheating temperature is preferably 110 (rc or higher). When the steel is reheated to a temperature lower than 1100 ° C, the rough deposits generated during continuous processing are caused by the low reheating temperature. While maintained in an incompletely melted state, the rough deposits continue to exist after hot rolling. Preferably, the hot rolling is performed in a state where the finishing roll is performed at an A 3 transformation temperature or higher. This Due to the fact that performing fine 10 rolls below the Ar3 turning temperature will cause rolling particles, the ductility and shapeability of the steel sheet are significantly reduced. After hot rolling, the cooling rate is better 200 ° C / min or more. More specifically, there are slight differences in cooling rates between (l) MnS-precipitated steel, (2) CuS-precipitated steel, and (3) MnCi ^ Shendian steel. 15 First, in the case of MnS-precipitated steel, the cooling rate is preferably 20 ° C./minute or higher. Even when the composition of manganese and sulfur satisfies the relationship according to the present invention: 0.58 * manganese / sulfur & lt 10, one lower than 200. (: / min cooling rate can cause rough MnS sinking with a size greater than 0.2 μm This is due to the fact that when the cooling rate is increased, many crystal nuclei are generated, so the 20M] lSrL chemotactic substance becomes fine. When the composition of manganese and sulfur has this relationship: 〇58 chain / Carbon> 10, which increases the number of coarse bond precipitates in the incompletely dissolved state during the reheating process. Therefore, even if the cooling rate is increased, the number of crystal nuclei will not be increased, and therefore the Mns precipitate will not be increased. It becomes finer (Figure 2b, 002% carbon; 0.03% manganese; 0.001%) phosphorus; 009% 24 200521249 sulfur; 0.035% Shao and 〇 · 〇〇43% nitrogen, expressed in plus%). Refer to Section 2aA2b® 'Thin MnS sinker caused by increased cooling rate, does not need to provide the upper limit of the cooling rate. However, even when the cooling rate It is looot / minute or higher, because the size of the Mns 5 sinker will not be reduced any more. The cooling rate is preferably between 2000 and ⑽❿ minutes.… Next, the example of C4 sinker steel After heating, the rate is preferably 300 C / min or higher. Even when the composition of copper and sulfur is based on It is clear that the relationship is satisfied: 〇5 * copper / sulfur &lt; 10, one less than 300. The / rate in the knife name can cause a thick chain with a size larger than 〇1㈣. As a matter of fact, when the cooling rate is increased, many crystal nuclei 1 are generated, so the CuS precipitate becomes fine. When the composition of copper and sulfur has the f-type 0.5 Cu /; 5; u &gt; 10, During the reheating process, the number of precipitates in the incompletely dissolved state is increased. Therefore, even if the cooling rate is increased, the number of crystal nuclei will not be increased, and therefore the CuS precipitate will not become finer. (Figure 3C, 0% 9% carbon; 0.01% dish; 0.005% stone claw, 0.03% Shao; 0.0015% nitrogen and 0.0028% copper to% 7] Τ) Cangzhi Figures 3a to 3c, due to the increase of the cooling rate, resulting in a thinner 222 S sink, and it is not necessary to provide an upper limit for the cooling rate. However, even when the cooling rate is adjusted. (: / Minute or higher, because the size of the CuS material will not be reduced, the cooling rate is preferably between 300 and 〇. Minutes. Figures 3a and 3b (0.00) 8% carbon; 0.001% phosphorous; 0.005% stone claws; 0.003% aluminum; 0.0024% nitrogen and 0.0081% copper, respectively, heart watch 25 200521249 No) respectively 0.5 * copper Examples of / sulfur and 0.5 * steel / sulfur> 3. With reference to these figures, it can be seen that when the value of 0.5 * copper / sulfur is 3 or less, it is more stable to have ΐ μ1Ί1 or smaller size 匸 deposits. Then '(2) In the example of] y [nCu-Shendian steel, after hot rolling, the cooling rate is preferably 300 ° C / min or more High. Even when the composition of manganese, copper, and sulfur satisfies the relationship according to the present invention ... 2 ^ 0 · 5 * (| Meng + steel) / sulfur ^ 20, a cooling rate below 300 ° C / min may be Causes a coarse precipitate with a size greater than 0 2 μΐΏ. This is due to the fact that when the cooling rate is increased, many crystal nuclei are generated, so the precipitate becomes fine. When the group of manganese, copper and sulfur has 10% The relationship ... 0.5 * (manganese + copper) / &gt; 20, the number of rough precipitates in an incompletely dissolved state is increased during the reheating process, so even if the cooling rate is increased, the number of crystal nuclei will not be increased, and therefore the precipitates will not become Fine (Figure 4b, 0.0025% carbon; 0.4% fibrous; 0.01% phosphorus; 0.001% sulfur; 0.05% aluminum; 0.0016 ° / 〇 nitrogen and 15 〇15 % Copper, expressed as a free%). Referring to Figures 4a and 4b, it is not necessary to provide the upper limit of the cooling rate due to the finer precipitation caused by increasing the cooling rate. However, even when the cooling rate is 1000 ° C / Min or higher, because the size of the precipitate will not be reduced any more, the cooling rate is preferably 300 ~ 1000 ° C / min or higher. 20 Winding front 1 After the above hot rolling process, The winding procedure is preferably performed at a temperature of 700 ° C or less. When the winding procedure is performed at a temperature higher than 700 ° C, the Shenyang system is generated with too thick chains, so Reduce the aging resistance of the steel. 26 200521249 Cold-rolled conditions The steel is cold-rolled to a desired thickness. A cross-section shrinkage of ~ 90%. A cross-section shrinkage of less than 50% results in a V-day nucleus at the recrystallization annealing date, and the crystal grains are excessively grown during annealing. 5 Therefore It produces coarse chain grains that recrystallize through annealing, thus reducing the strength and plasticity of the steel sheet. A cold rolling reduction of more than 90% leads to enhanced plasticity, which results in an excess of At the time of crystal nucleus, therefore, the particles recrystallized by annealing become excessively fine, thereby reducing the ductility of the steel. 10 Continuous de-gamma continuous annealing temperature plays an important role in determining the physical properties of the product. According to the present invention, it is preferably between 500 and 900. Continuous annealing is performed at a temperature of 〇. Continuous annealing at a temperature below 500t: excessive temperature

The recrystallized grains of Uw cannot obtain the desired ductility. Continuous annealing at a temperature of 10 ° C results in rough recrystallized grains, so the strength of Newton ^ steel is only strong. Continue the retention time of continuous annealing to complete the remodeling of the steel. The recrystallization of the steel can be completed in 10 seconds or more during continuous annealing. The present invention will be described in detail with the following examples. In the description of the following examples, the steel sheet is mechanically manufactured as a standard sample according to the ASTM standard &lt; ASTM standard, and its physical properties are measured by using a tensile strength tester (from INSTRON &amp; Obtained by the company, type 6025); then measure the equivalent strength, the tensile strength, the extension, the plasticity, the number of 11 cores (), the value, the anisotropy index (△) · value in the plane), and The Aging 27 200521249 Index (AI). In these examples, 'the plasticity_inwardness index is obtained by the following equation: continued (rni = (r〇, 2 145 r9G) / 4 and &amp; = (1, Q 2 k + ^ 90) / 2) (Mm the flat anisotropy remainder (domain). ”In order to obtain the average size and number of sinks distributed in the sample, the size of all the sinks present in the material is measured. [Example M] MnS-precipitated steel In order to complete the secret sinking steel according to the present invention, after the steel plate is lightened and lightened to lift and roll the steel sheet, the steel plate shown in the table is reheated to After a temperature of 1200 ° C, the hot-rolled steel sheet was cooled at a rate of 20 (rc / min) and wound at 650 C. Then, after continuous annealing, cold rolling was performed at a reduction rate of 1 to 0 / °. The hot-rolled steel sheet. A finishing roll is performed at 91.0 °, which is above the Ar3 transformation temperature, and by continuously heating the 15 steel sheet at a speed of 10.0 / sec for 40 seconds to perform continuous Annealing. The exception is that sample 8 in Table 丨 is reheated to a temperature of ι050 ^ and followed by finishing rolls, and the sample is cooled at a rate of 50 ° C / min. And then at 75. (: rolled. Table 1 20 Sample No. Carbon C 0.003 ~~ ϊΐ Μη ~ 0.05-0.2 [—phosphorus P 0.015 sulfur S 0.005-0.03 composition (wt1 aluminum A1 0.01-0.1%) nitrogen N 0.004 IVIo 0.01-0.2 Vanadium V 0.01-0.2 R ·] 10 321 1-20 A1 0.0023 0.08 0.01 0.005 0.04 0.0015--9.28 A2 0.0018 0 ·] 0 0.011 0.012 0.05 0.0026 *-4.83 A3 0.0018 0.15 0.008 0.015 0.03 0.0012 --5.8 ------- 28 200521249

A4 0.0027 0.09 0.012 0.025 0.035 0.0018--2.09 A5 0.0026 0.4 0.009 0.01 0.02 0.0039--23.2 A6 0.0038 0.10 0.011 0.008 0.05 0.0038--7.25 A7 0.0015 0.35 0.01 0.032 0.03 0.0015--6.34 A8 0.0023 0.08 0.01 0.008 0.04 0.0015--5.8 A9 0.0013 0.09 0.0] 0.008 0.033 0.025 0.03-6.53 A10 0.0022 0.15 0.012 0.011 0.025 0.0022 0.053-7.9] All 0.0015 0.10 0.008 0.015 0,043 0.0023 0.074-3.87 A] 2 0.0025 0.] 0.009 0.02] 0.034 0.0028 0.] 1-2.76 A13 0.0022 0.12 0.009 0.014 0.03 0.0021 0.15-4.97 A14 0.0022 0.4 0.009 0.009 0.032 0.0033 0.25-25.8 A] 5 0.0015 0.1 0.011 0.009 0.033 0.0025-0.023 6.44 3.83 A] 6 0.0024 0.08 0.01 0.0] 0.035 0.0012-0.05] 4.64 5.13 A17 0.0025 0.12 0.008 0.012 0.023 0.0015-0.08 5.8 8 A18 0.0015 0.11 0.01 0.02 0.032 0.002 &gt; 0.11 3.19 18.3 A19 0.0027 0.08 0.008 0.01 0.033 0.00]]-0.154 4.64 14.3 A20 0.002 0.4 0.01 0.013 0.022 0.0013-0.325 17.8 30 A21 0.0023 0.11 0.011 0.011 0.023 0.0017 0.017 0.025 5.8 2.72 A22 0.0027 0.09 0.0 1 0.009 0.037 0.0027 0.074 0.082 5.8 7.59 A23 0.0025 0.08 0.009 0.012 0.032 0.003] 0.15 0.16 3.87 16 Note: Rl = 0.58 * manganese / sulfur, R-2 = 0.25 * vanadium / carbon ) Note YP (Mpa) TS (MPa) Ε] (%) r-value (rm) Ar-value (Δγ) A] (MPa) A1 211 309 49 1.83 0.28 23 0.05】 S A2 209 311 52 1.93 0.34 22 0.12 IS A3 201 295 54 1.94 0.31 21 0.15 IS

29 200521249 A4 223 319 48 1.88 0.23 27 0.14 1S A5 2Π 312 48 1.93 0.52 34 0.62 CS A6 254 329 45]. 57 0.41 49 0.09 CS A7 222 316 48 1.82 0.58 38 0.46 CS A8 200 291 53 1.69 0.48 37 0.34 CS A9 213 311 50 2.24 0.31 15 0.06 IS A10 209 307 53 2.15 0.25 25 〇.] 1 IS All 219 318 49 2.34 0.28 16 0.12 IS A12 220 321 49 2.25 0.24 26 0.13 IS A13 234 328 49 2.20 0.31 24 0.14 IS A14 241 333 47 2.01 0.43 42 0.54 CS A15 175 295 50 1.82 0.26 0 0.06 IS A16 163 301 53 1.86 0.21 0 0.11 IS A17 158 284 49 1.9 0.19 0 0.12 IS A18 148 278 49 1.77 0.17 0 0.13 IS A19] 75 302 49 1.74 0.18 0 0.14 IS A20 182 308 47 1.52 0.21 0 0.54 CS A21 158 290 50 2.19 0.35 0 0.07 IS A22 162 288 49 2.22 0.39 0 0.08] s A23 _] 72 292 49 2.08 0.29 0 〇]] IS Note: γρ = equivalent strength , TS = tensile strength, El = elongation, r-value: plasticity-anisotropy index, △ r-value: in-plane anisotropy index, AI = aging index, AS = average size of sediment,] S = Steel of the invention, CS = Comparative steel

As shown in Table 2, the steel of the present invention has not only high aging resistance, but also high equivalent strength and excellent moldability. At the same time, sample A5 had a coarse precipitate of 0.58 * manganese / sulfur value of 23.2, an average size of 0.62 μηΊ, and an aging index of 34 MPa, which caused 30 200521249 to have inferior aging resistance. The sample A6 has a high content of carbon, and therefore has an aging index of 48 MPa, which is excessively high and also causes poor aging resistance. The sample A7 had a manganese / sulfur value of 6.34 * 58 *, which is within the scope of the present invention. However, it has a manganese and sulfur content beyond the scope of the present invention, which causes a MnS sinker of crude sugar, thus providing an aging index of 38 MPa. Therefore, in Sample A7, the aging resistance cannot be ensured, and the plasticity of the steel sheet is poor. Exceptionally, in the example of sample A8, because the recrystallization temperature is 1050t, which is very low, the precipitates were not completely dissolved in the reheating process, resulting in an excessive amount of 10 The precipitates are not completely dissolved, and because of an extremely high winding temperature, the precipitates are thick chain sinks with an average size of 0.34 μm, so it is difficult to ensure the aging resistance. [Example 1-2] High strength Cu S-precipitated steel 15 with solid solution strengthening effect In order to achieve the high-strength CuS-precipitated steel according to the present invention, the steel plate shown in Table 3 was reheated to 120 °. After the steel sheet is hot-rolled with the steel sheet continuously heated at a temperature of ° C, the steel sheet is cooled at a rate of 200 ° C / min, and wound at 65 ° :. Next, the hot-rolled steel sheet is continuously cold-rolled at a 75% cross-sectional shrinkage ratio of 20% and continuous annealing is continued. The lamp was lightened at 91 ° C, which was above the Ar3 transformation temperature, and by 10 °. The steel sheet is heated at a rate of 0 / second for 40 seconds to 750 ° C to perform continuous annealing.

Ingredients (wt%) 3] 200521249 Numbered carbon C Manganese Mn Phosphorus P Silicon Si Chromium Ci. Sulfur A] Ν Molybdenum Mo Vanadium V R-1 R-2 0.003 0.05-0.2 0.2 0.1-0.8 0.2-1.2 0.005- 0.03 0.01-0.1 0.004 0.01-0.2 0.01-0.2 10 1-20 B1 0.0023 0.08 0.052--0.006 0.04 0.0015--7.73 B2 0.0018 0.10 0.102--0.010 0.05 0.0026--5.8 B3 0.0025 0.08 0.151--0.012 0.035 0.0018-- 3.87 B4 0.0022 0.4 0.109--0.011 0.05 0.0038--21.1 B5 0.0024 0.4 0.07--0.01 0.04 0.0016 Titanium: 0.05-B6 0.0019 0.11 0.01 0.22-0.008 0.04 0.0012 &gt;-7.78 B7 0.0018 0.1 0.011 0.62-0.009 0.035 0.0025--- 6.4 B8 0.0026 0.42 0.01 0.25-0.01 0.03 0.0028--24.4 B9 0.0024 0.09 0.01-0.32 0.007 0.05 0.0012--7.46 B10 0.0022 0.11 0.015-0.63 0.012 0.04 0.0028--5.3] ΒΠ 0.0018 0.11 0.011-0.95 0.015 0.03 0.0022--4.25 B12 0.0017 0.1 0.048--0.01 0.034 0.0025 0.025-5.8 B13 0.002 0.09 0.011 0.21-0.01 0.024 0.0018 0.02-5.22 B14 0.0014 0.1 0 · 0] 1-0.3 0.008 0.03 0.0032 0.025-7.25 B15 0.002 0.09 0 .048 0.21 0.3 0.012 0.033 0.0022 0.]-4.35 B16 0.0018 0.11 0.05 &gt;-0.011 0.03 0.002-0.02 5.8 2.7 jj B17 0.0022 0.11 0.01 0.25-0.009 0.034 0.0022-0.021 7.08 2.39. B18 0.0015 0.11 0.0]-0.33 0.01 0.023 0.0022-0.02 6.38 3.33 B19 0.0023 0.09 0.054--0.01 0.043 0.0029 0.021 0.017 5.22 1.85 B20 0.0026 0.09 0.012 0.26-0.011 0.024 0.0019 0.019 0.016 4.75 1.54 B21 0.0025 0.11 0.01-0.33 0.01 0.023 0.0022 0.017 0.021 6.38 2.1 Note: R-] = 0.58 * manganese / sulfur, R-2 = 0.25 * vanadium / carbon Table 4 Sample number Physical properties AS (μιη) W Note 32 200521249

YP (MPa) D S (MPa) El (%) r-value (i * m) △ r-value (Ar) A1 (MPa) DB D T (Cc) B1 241 356 47 1.83 0.31 28 -70 0.11 IS B2 299 402 42 1.65 0.32 23 -50 0.09 IS B3 352 456 35 1.53 0.31 27 -40 0.14 IS B4 289 394 39 1.63 0.58 45 -60 0.73 CS B5 210 353 40 1.73 0.58 0 + 0-CVS B6 241 356 50 1.75 0.28 24 -80 0.1] IS B7 352 456 38 1.47 0.31 22 -50 0.14 IS B8 23] 346 45 1.72 0.58 42 -70 0.49 CS B9 235 352 47 1.70 0.20 21 -80 0.08 IS B10 299 418 44 1.51 0.19 18 -60 0.07 IS B11 349 459 36 1.42 0.23 16 -50 0.11 IS B12 238 359 46 2.09 0.3 18 -80 0.13】 s B13 238 362 48 2.09 0.32 22 -80 0.11 IS B14 228 358 48 2.17 0.25 15 -80 0.1 IS B15 350 470 35] .61 0.15 19 -60 0.1】 s B16 203 355 44 1.76 0.23 0 -70 0.12 IS B] 7 198 360 47 1.77 0.32 0 -70 0.13 IS B18 197 352 47 1.65 0.28 0 -80 0.]] IS B19 205 356 44 2.01 0.31 0 -60 0.11 IS B20 198 360 47 \ .ΊΊ 0.27 0 -70 0.13】 s B21 201 350 48 1.98 0.28 0 -70 0.07 IS Note: ΥP = equivalent strength, TS = tensile strength, Eb extension, r-va lue: plasticity-anisotropy index, △ r-value: in-plane anisotropy index, Al = aging index, DBTT = ductility-brittleness transition temperature used to study the moon tortoiseability of secondary work products. AS = Shen Average size of exciter, S = steel of the present invention, CS = steel of comparison, cVs = conventional steel 33 200521249 5 10 15 20 Ge Er? The sample—and coffee—has an a or more strength, an equivalent strength-ductility balance / strength; the extension, and _〇 materials have excellent plasticity (field strength ductility). The number of steels of the present invention, therefore, can be ascertained that the aging and -30 coffee or less aging refers to the book C or lower elongation = property. In addition, the present Japanese steel is excellent in terms of embrittlement. &amp; The temperature is changed, and the sample B5 is produced in the second-level work (a good aging index of conventional steels. It is a cold-strength steel sheet with high strength, and has a degree. Its high degree of fragmentation can be based on a high extension. The brittleness converts the temperature to the temperature of 'b' even when impacted at room temperature. J "has A1N condition cutting enhancement rot_Shen Dian Steel as shown in Table 5. The steel is refined to provide 敎 ^ heated to 12 thieves The temperature and the degree of continuity to cool the qing, μ ::. E, followed by cold rolling at a speed of -boots / minute to continue rolling. Then, fire at 75%. Perform correction at 9 , And ^ M materials and continued continuous withdrawal by adding I at the rate of nodal seconds above the AΓ3 transformation temperature 'and continuous annealing. Performed with steel sheet 40 seconds to 750t

table 5

34 200521249 C2 0.0028 0.09 0.042 0.007 0.04 0.0068 7.73 3.06 C3 0.0023 0.11 0.04 〇.〇] 〇0.05 0.0082 5.8 3.17 C4 0.0018 0.08 0.043 0.00.05 0.005 0.0065 3.87 4.4 C5 0.0022 0.09 0.04 〇.〇]] 0.008 0.0067 6.53 0.46 C6 0.0019 0.4 0.04 0.009 0.04 0.0083 25.8 2.51 C7 0.0015 0 ·]] 0.042 〇.0] 0.055 0.012 0.028 6.38 2.25 C8 0.0012 0.1 0.04 0.008 0.033 0.011 0.018 7.25 1.56 3.75 C9 0.0023 0.11 0.043 0.008 0.053 0 · 0]] 0.022 0.017 7.98 2.51 1.85 Notes: Rl = 0.58 * violent / sulfur, R-2 = 0.25 * 鈒 / carbon, R-3 = 0.52 * aluminum / nitrogen Table 6

Sample's physical properties AS (μηι) Note YP (MPa) TS (MPa) El (%) r-value (rm) △ r-va) ue (Ar) A] (MPa) DB Tintin (° C) C1 231 352 46 1.78 0.31 22 -70 0.07 IS C2 229 344 48 1.82 0.38 25 -70 0.09 IS C3 235 348 48 1.83 0.31 22 -70 0.09 IS C4 23] 346 48 1.82 0.32 25 -70 0.07] s C5 218 332 42 1.62 0.34 49 -70 0.12 cs C6 221 328 46 1.72 0.54 38 -70 0.38 cs C7 225 355 47 2.15 0.31 12 -80 0.08 IS C8 195 354 47 1.76 0.29 0 -70 0.09 IS C9 198 350 48 1.99 0.29 0 -70 0.1 IS △ Bu⑹ ^ In-plane anisotropy index, A1 = aging index, bribe = ductility used to study the embrittlement of secondary work products. Pu 11 transition temperature, AS = average size of sinker,] s = Cs = Comparative steel material of the present invention '10 [Example 2-] CuS-precipitated steel material 35 200521249 The steel plate shown in Table 7 was reheated to 1200. After finishing rolling the steel sheet to provide a hot-rolled steel sheet, the steel sheet was cold-rolled to 650 ° C at a speed of 4,000 c / minute. Next, the hot-rolled steel sheet was continuously cold-rolled at a 75% reduction in area and continuous annealing was continued. At 91. (: Perform 5 lines of light rolling, which are above the Ar3 transformation temperature, and perform continuous annealing by heating the steel sheet at a rate of 10 ° c / sec for 40 seconds to 7500c. The exception is' In the example of sample D8 in Table 7, after reheating to a temperature of 1050 ° C and then finishing rolls, the sample was cooled at a rate of 400 ° C / minute and then at 650. (: winding. In addition, In Example 10 of samples D14-D17, after reheating to 1250 ° C and then finishing rolls, the samples were cooled at a rate of 550 C / min and then wound at 6500c. Table 7 Samples Oral composition (wt%) Oral P Weave carbon C Phosphorus P Sulfur S Aluminum A1 Nitrogen N Copper Cu Molybdenum Mo Vanadium V R-4 R-2 0.003 0.015 0.003-0.025 0.01-0.] 0.004 0.01-0.2 0.01-0.2 0.01- 0.2 1-10 1-20 D1 0.0017 0.007 0.008 0.04 0.0028 0.035 2.19 D2 0.0018 0.010 0.008 0.05 0.0014 0.041 2.56 D3 0.0016 0.012 0.015 0.03 0.0012 0.083 2.77 D4 0.0025 0.00 0.005 0.02 0.0039 0.021 2.1 D5 0.0018 0.0] .0.005 0.03 0.0024 0.081 8.1 D6 0.0022 0 · 0]] 0.012 0.05 0.0038 0.005 0.21 D7 0.0019 0.01 0.005 0.03 0.0015 0.28 28 D8 0.0018 0.010 0.008 0.05 0.0014 0.041 2.56 D9 0.0015 0 · 0] 0.01 0.035 0.0022 0.038 0.015 1.9 D10 0.0028 0.011 0.008 0.025 0.0021 0.045 0.05 2.81 36 200521249 D11 0.0018 0.01 0.012 0.033 0.0032 0.084 0.1] 3.5 D12 0.0024 0.01 0.009 0.042 0.0029 0.031 0.] 7 1.72 D13 0.0028 0.011 0.012 0.035 0.0024 0.035 0.28 1.46 D14 0.0018 0.009 0.01] 0.025 0.0026 0.03 0.025 1.36 3.47 D15 0.002 0.012 0.009 0.022 0.0011 0.052 0.075 2.89 9.38 D16 0.0026 0.0]] 0.008 0.028 0.0038 0.084 0J7 3.82 16.3 D17 0.002 0.012 0.01 0.039 0.0044 0.065 0.28 3.25 35 D18 0.0016 0.011 0.009 0.035 0.0037 0.043 0.021 0.017 2.39 2.66 D19 0.0022 0.01 0.01 0.042 0.0024 0.058 0.075 0.082 2.9 9.32 D20 0.0027 0.01 0.0]] 0.022 0.0022 0.064 0.17 0.15 5.82 13.9 Note: R-2 = 0.25 * Vanadium / carbon, R-4 = 0.5 * copper / sulfur Table 8 Sample number Physical properties AS (μιη) Note YP (Mpa) TS (MPa) E] (%) r-value (rm) Ar-value (△) · ) A] (MPa) D1 206 298 53 2.15 0.29 21 0.08 IS D2 189 312 52 2.33 0.38 18 0.05 IS D3 223 321 50 2.29 0.29 21 0.05 IS D4 197 319 319 53 2.23 0.35 28 0.07 IS D5 218 316 52 2.18 0.25 29 0,09 IS D6 189 296 54 2.58 0.79 46-cs D7 209 309 46 1.87 0.53 51 0.34 cs D8 173 275 58 2.62 1.09 49 0.49 cs D9 193 300 53 2.58 0.32 19 0.09 IS D10 211 310 52 2.63 0.35 25 0.07 IS D11 202 301 50 2.49 0.28 20 0.07 IS D12 207 312 52 2.53 0.33 23 0.07 IS D13 215 326 48 2.28 0.51 29 0.19 cs 37 200521249

[Example 2 2] High strength CuS-precipitated steel with solid solution strengthening effect. The steel plate not shown in Table 9 was reheated to a temperature of 1200 ° C to continue finishing the roll to provide the hot rolled steel sheet. The hot-rolled steel sheet was cooled at a speed of 400 (t / min, and was rolled at 65. (: winding. Then, the rolled steel sheet was continuously cold-rolled at a reduction of 10 to 75%). The material is continuously annealed. A finishing roll is performed at 91 ° C, which is above the Ar3 transformation temperature, and by heating the steel sheet at a rate of 10 ° C / sec. For 40 seconds to 7 ° C. Continuous annealing is performed. 15 Table 9 Sample σ] Composition (wt%) ΌΟ Number carbon C phosphorus P silicon Si road Cr sulfur S aluminum A1 nitrogen N copper Cu molybdenum Mo vanadium V R-4 R-2 0.003 0.2 0.1-0.8 0.2- 1.2 0.003-0.025 〇.〇] &gt; 0.] 0.004 0.01-0.2 0.01-0.2 0.01-0.2 1-10 1-20 Ε] 0.0021 0.045 j 0.015 0.04 0.0018 0.045 1.5 Ε2 0.0015 0.048 0.013 0.03 0.0023 0.06 2.25 Ε3 0.0021 0.1 1 0.011 0.04 ---__ 0.0015 0.056 2.55 _1_ 38 200521249 E4 0.0025 0.11 0.011 0.04 0.0038 0.106 4.82 E5 0.0018 0.16 0 .008 0.05 0.0012 0.141 8.81 E6 0.0018 0.05 0.01 0.02 0.0039 0.005 0.25 E7 0.0022 0.109 0.011 0.05 0.0038 0.32 14.5 E8 0.0022 0.01 0.23 0.015 0.04 0.0014 0.045 1.5 • E9 0.0024 0.009 0.21 0.012 0.05 0.0024 0.052 2.15 • E10 0.0025 0.01 0.4 0.008 0.04 0.0018 0.045 2.81 Ell 0.0015 0.012 0.43 0.01 0.04 0.0032 0.087 4.34 E12 0.0021 0.010 0.63 0.008 0.035 0.0012 0.14] 8.81 钃 E13 0.0026 0.01 0.25 0.0] 0.03 0.0028 0.004 0.2 E14 0.0017 0.012 0.41 0.005 0.04 0.0032 0.221 22.1 E15 0.0024 0.01 0.30 0.012 0.04 0.0022 0.043 1.8 E16 0.0021 0.012 0.33 0.01 0.04 0.0018 0.05 2.5 E17 0.0024 0.009 0.60 0.009 0.05 0.0032 0.05 2.78 E18 0.0024 0.013 0.63 0.009 0.04 0.0028 0.078 4.33 E19 0.0016 0.009 0.95 0.005 0.04 0.0032 0.083 8.3 E20 0.0026 0.011 0.35 0.012 0.04 0.0028 0.008 0.33 E21 0.0025 0.009 0.61 0.011 0.05 0.0023 0.252 14 i E22 0.0025 0.052 0.012 0.023 0.0033 0.054 0.035 2.25 E23 0.0014 0.0] 0.23 0.009 0.035 0 .0034 0.05 0.022 2.78 E24 0.0014 o.on 0.33 0.0] 0.034 0.0024 0.04 0.018 2 E25 0.0015 0.055 0 · 0] 0.043 0.0023 0.052 0.023 2.6 3.83 E26 0.0012 0.009 0.25 0.011 0.023 0.0014 0.055 0.024 2.5 5 E27 0.0012 0.01 0.35 0.009 0.034 0.0025 0.042 o.on 2.33 3.54 E28 0.0024 0.054 0.012 0.034 0.0023 0.05 0.018 0.02 2.08 2.08 E29 0.0017 0.01 0.26 0.01 0.032 0.0024 0.05 0.022 0.018 2.5 2.65 E30 1 0.0023 0.011 0.34 0.01 0.024 0.0024 0.046 0.021 0.01S 2.3 1.96 39 200521249 Note: R-2 = 0.25 * vanadium / carbon, R-4 = 0.5 * copper / sulfur Table 10 Sample number Physical properties AS (μηι) Note YP (MPa) TS (MPa) El (%) r-value (rm) Ar-value (△ 0 AI (MPa) DB Tintin (° C) E1 265 360 49 1.85 0.24 25 -70 0.05 IS E2 27] 365 49 1.83 0.25 22 -70 0.05 IS E3 301 410 41 1.73 0.24 21 -50 0.06 IS E4 299 402 42 1.69 0.22 27 -50 0.06 IS E5 352 456 35 1.53 0.18 21 -40 0.09 IS E6 208 326 50 1.85 0.61 35 -60 0.38 cs E7 278 382 39 1.59 0.58 45 ^ 50 0.55 cs E8 270 355 52 1.85 0.28 21 -80 0.06 IS E9 27] 359 48 1. 75 0.28 28 -80 0.06 IS E10 300 406 45 1.68 0.26 25 -60 0.07 IS E11 306 409 43 1.63 0.25 22 -60 0.07 IS E12 363 459 35 1.45 0.21 26 -50 0.05】 s E13 231 346 45 1.79 0.61 49 -70 0.49 cs E14 279 392 38 1.66 0.47 37 -60 0.51 cs E15 262 356 48 1.75 0.25 19 -80 0.07 IS E16 265 350 48 1.75 0.23 17 -80 0.07 IS E] 7 310 405 42] .63 0.22 18 -60 0.05 IS E18 302 408 40 1.58 0.22 20 -60 0.05 IS E19 354 451 35 1.51 0.22 16 -50 0.06 IS E20 212 339 47 1.74 0.49 37 -70 0.38 cs 40 200521249 E21 279 393 43 1.64 0.42 39 -60 0.35 CS E22 265 355 48 2.18 0.27 25 -80 0.06 1S E23 262 355 49 2.03 0.26 18 -80 0.06 IS E24 252 356 47 2.03 0.31 15 -80 0.06 IS E25 224 357 47 1.82 0.32 0 -70 0.07 IS E26 216 357 48 1.77 0.27 0 -80 0.07 IS E27 222 350 47 1.72 0.25 0 -80 0.08 IS E28 210 361 48 2.12 0.38 0 -70 0.06 IS E29 210 355 50 2.11 0.34 0 -70 0.08 IS E30 213 355 48 2.14 0.35 0 -70 0.08] s Note: ΥΡ = Equivalent strength, TS = tensile strength, Eb extension, r-va] ue: plasticity-anisotropy index, △ r-value : In-plane anisotropy index, A] = aging index, DBTT = ductility-brittleness transition temperature used to study the brittleness of secondary work products, AS = average size of precipitates,] S = steel of the present invention, CS = Comparative steel [Example 2-3] High-strength CuS-precipitated steel with A1N precipitation enhancement. The steel plate shown in Table 11 was reheated to a temperature of 1200 ° C to continue the finishing roll to provide the hot-rolled steel. After the sheet, the hot-rolled steel sheet was cooled at a rate of 40 ° C./minute, and wound at 650 ° C. Next, the rolled steel sheet is continuously cold-rolled at a reduction of 10 to 75%, and continuous annealing is continued. A finishing roll is performed at 910 ° C, which is above the Ar3 transformation temperature, and continuous annealing is performed by heating the steel sheet at a rate of 10 ° C / second for 40 seconds to 750 ° C. Exceptionally, in the examples of samples F8-F10, after reheating to a temperature of 1250 ° C and then finishing rolls, the samples were cooled at a rate of 15 550 ° C / minute and then rolled at 650 ° C Around. Table]] 41 200521249 Sample No. Composition (vt%) Carbon C Phosphorus P Sulfur Aluminum Al Nitrogen N Copper Cu Molybdenum Mo Vanadium V R-4 R &gt; 3 R-2 Ratio 0.003 0.03-0.06 0.003-0.025 0.01-0.1 0.005 -0.02 0.01-0.2 0.01-0.2 0.01-0.2 1-10 1-5 1-20 F1 0.0018 0.042 0.015 0.032 0.013 0.051 1.7 1.72 F2 0.0023 0.04 0.012 0.032 0.0097 0.05 2.08 1.72 F3 0.0018 0.042 0.009 0.042 0.0072 0.086 4.78 3.03 F4 0.0015 0.05 0.007 0.057 0.0080 0.123 8.79 3.71 F5 0.0025 0.043 0.01 0.042 0.0072 0.007 0.35 3.03 F6 0.0022 0.042 0.009 0.038 0.0014 0.075 4.17 14.1 F7 0.0016 0.04 0.011 0.008 0.0028 0.0】 0.45 1.49 F8 0.0015 0.044 0.011 0.065 0.0077 0.037 0.022 1.68 4.39 F9 0.0022 0.044 0.011 0.043 0.011 0.043 0.011 0.056 0.019 2.55 2.03 2.16 F10 0.0017 0.042 0.01 0.033 0.0092 0.035 0.022 0.017 1.75 1.87 2.5 Note: R-2 = 0.25 * vanadium / carbon, R-3 = 0.52 * aluminum / nitrogen, R-4 = 0.5 * copper / sulfur Table 12

Sample number Physical properties AS (μηι) Note YP (MPa) D S (MPa) E] (%) r-value (l'm) △ r-value (Δ〇A) (MPa) DBTT (° C) F1 250 355 48 1.86 0.34 22 • 70 0.04 IS F2 259 362 48 1.82 0.34 25 -70 0.04 IS F3 262 352 46 1.85 0.38 23 -70 0.06 IS F4 255 348 48 1.88 0.35 22 -70 0.07 IS F5 233 331 50] .88 0.39 25 -70 0.21 cs F6 22] 320 48 1.83 0.42 26 -70 0.18 cs F7 218 322 49 1.82 0.34 49 -70 0.12 cs F8 202 357 48 2.03 0.33 18 -70 0.08 IS 42 200521249

[Example 3-1] The steel plate shown in Table 13 of MnCu-Shendian Steel was reheated to a temperature of 12,000 t: to finish rolling the steel plate to provide a hot-rolled steel sheet. The hot-rolled steel sheet is cooled at a rate of 1 / min, and is rolled at 65 °. (: The coil is rolled. Then, the rolled steel sheet is cold-rolled at a reduction of 10 to 75% and continued to be annealed with iridium A finishing roll is performed at 910c, which is above the Ar3 transformation temperature, and continuous annealing is performed by heating the steel sheet at a rate of 10 ° C / sec for 40 seconds to 75 ° C. Exceptionally, at In the example of sample G10 in Table 13, after reheating to a temperature of 1050 ° C and then finishing rolls, the sample was cooled at a rate of 5015 C / min and then wound at 750 ° C. 13 Sample No. Composition (wt0 / 〇) Carbon C Mg Phosphorus P Sulfur Aluminum A] Nitrogen N Copper Cu Molybdenum] VIo Vanadium V R-5 R-6 R-2 0.003 0.03-0.2 0.015 0.003-0.025 0.01-0.1 0,004 0.01- 0.2 0.0! &Gt; 0.2 0.01-0.2 0.3 2-20 1-20 G] 0.002] 0.08 0.012 0.005 0.04 0.0023 0.082 0.16 16.2 G2 0.0018 0.11 0.009 0.009 0.04 0.0019 0.04 0. 15 8.33 G3 0.0022 0.09 0.012 0.011 0.05 0.0024 0.05 0.14 6.36 G4 0.0024 0.15 0.008 0.02] 0.05 0.0018 0.04 0.19 4.52 G5 0.0022 0.05 0.008 0.018 0.04 0.0024 0.035 0.09 2.36 43 200521249

G6 0.0024 0.4 0.011 0.012 0.05 0.0038 0.023 0.4 17.6 G7 0.0028 0.05 0.012 0.018 0.04 0.0023 0.012 0.06 1.72 G8 0.0025 0.25 0.01 0.008 0.03 0.0015 0.18 0.4 26.9 G9 0.0022 0.15 0.013 0.005 0.03 0.0026 0.12 0.27 27 G10 0.0025 0.] 0.010 0.010 0.03 0.0014 0.042 0.14 7.1 G11 0.0023 0.11 0.01 0.011 0.024 0.0033 0.08 0.018 0.19 8.64 G12 0.0023 0.12 0.011 0.009 0.033 0.0023 0.082 0.021 0.20 11.2 2.28 G13 0.0017 0.1 0.01 0.009 0.036 0.0032 0.042 0.019 0.023 0.14 7.89 3.38 Note: R-2 = 0.25 * vanadium / carbon, R-5 = manganese + copper, R-6 = 0.5 * (manganese + copper) / sulfur Table 14

Physical properties AS (μιη) PN (number / mm2) Note YP (Mpa) TS (MPa) E) (%) r-value (rm) Ar-value (Δγ) Αϊ (MPa) G1 198 292 51 2.32 0.38 17 0.09 4.5X106 IS G2 208 309 52 2.35 0.35 16 0.08 9.4X106 IS G3 221 314 55 2.51 0.26 21 0.06 2.2X108 IS G4 218 3] 0 56 2.55 0.28 18 0.05 3.5X108 IS G5 205 300 58 2.68 0.31 23 0.05 4.1X108】 s G6 175 282 58 2.83 0.93 35 0.38 8.5X104 cs G7 163 270 60 2.78 1.12 36 0.48 4.3X104 cs G8 169 278 52 2.23 0.93 44 0.53 4.5X104 cs G9 189 286 51] .93 0.79 42 0.33 6.3X104 cs G10 181 291 55 2.45 0.88 35 0.38 7.] X] 04 cs G]] 209 302 50 2.83 0.45 25 0.09 3.5 X106 IS G12 162 291 51 2.21 0.29 0 0.08 4.2X106 IS G13 159 298 53 2.52 0.39 0 0.09 3.2X106 JS 44 200521249 Notes: γρ = equivalent strength, TS = tensile strength, E1 = extended, bu vaiue: anisotropy index in the plane of flexibility, A1 = aging index, two; the number of secondaries, the number of objects ,: rs = steel material of the present invention, comparative steel material and average size, 5 [Example 3-2] The material has solid solution reinforcement High strength M n c H temple steel

The steel plates shown in Table 15 were reheated to 1200. After the continuous rolling of the steel sheet to provide a hot-rolled steel sheet, the hot-rolled steel sheet is cooled at a rate of 600 ct / 2 minutes and wound at 65 ° rc. A reduction of 10% is followed by cold rolling of the rolled steel sheet and continuous annealing. The finishing roll is performed at 9HTC, which is above the Ar3 transformation temperature, and by 10 ° c The steel sheet is heated at a rate of 40 seconds to 0 ° C and continuous annealing is performed. 15 Table 15 Sample number composition (wt%) Carbon C 0.003 Manganese Mn 0.03- 0.2 Phosphorus P 0.2 Silicon Si 0.8 Cr Cr 0.2- 1.2 Sulfur 0.003-0.025 Aluminum A1 0.1 Nitrogen N 0.004 Copper Cu 0.01- 0.2 Molybdenum Mo 0.01- 0.2 Rail V 〇.〇] &gt; 0.2 R-5 R-6 R-2 0.3 2-20 1-20 H1 0.0022 0.05 0.05 0.015 0.04 0.0018 0.03 0.08 2.67 H2 0.00] 5 0.08 0.048 0.015 0.03 0.0023 0.04 0.12 4 H3 0.0027 0.07 0.105 0.02 0.05 0.0019 0.05 0.12 3 H4 0.0025 0.] 2 〇]] 0.0Π 0.04 0.0038 0.08 0.2 9.09 H5 0.0018 0.1 0.16 0.008 0.05 0.0012 0.14 0.24 15 H6 0.0018 0.05 0.05 0.015 0.02 0.0039 0.005 0.055 1 .83 H7 0.0022 0.1 0.109 0.011 0.05 0.0038 0.25 0.35 15.9 Η 8 0.0025 0.2 0.155 0.006 0.05 0.0038 0.08 0.28 23.3 Η 9 0.0017 0.0S 0.052 0.01 0.034 0.0018 0.043 0.022 0.12 6.15 45 200521249 H10 0.0027 0.1 0.05 0.014 0.034 0.0018 0.043 0.018 0.14 5. Π 1.67 H11 0.0017 0.11 0.052 0.012 0.024 0.0021 0.05 0.019 0.028 0.163 6.8 4.1 H12 0.002] 0.05 0.009 0.23 0.018 0.05 0.0023 0.03 0.08 2.22 H13 0.0026 0.12 0.01 0.22 0.013 0.05 0.0026 0.03 0.15 5.77 H14 0.0016 0.1 0.012 0.40 0.018 0.04 0.0032 0.05 0.15 4.17 H15 0.0021 0.12 0.012 0.40 0.015 0.04 0.0032 0.08 0.2 6.67 H16 0.0021 0.15 0.010 0.63 0.008 0.035 0.0012 0.141 0.291 18.2 H17 0.0016 0.05 0.009 0.25 0.02 0.04 0.0028 0.005 0.055 1.38 H18 0.0021 0.18 0.011 0.43 0.006 0.04 0.0032 0.] 0.28 23.3 H19 0.0022 0.3 0.009 0.60 0.015 0.05 0.0039 0.23 0.53 17.7 H20 0.0025 0.09 0.011 0.25 0.012 0.035 0.0013 0.032 0.02 0.122 5.08 H21 0.002 0.1 0.01 0.23 0.009 0.03 0.0026 0.043 0.017 0.1 4 7.94 2.13 H22 0.0017 0.11 0.012 0.25 0.01 0.033 0.0036 0.045 0.018 0.019 0.16 7.75 2.79 H23 0.0024 0.05 0.01 0.30 0.016 0.04 0.0022 0.04 0.09 2.81 H24 0.0018 0.12 0.009 0.32 0.012 0.05 0.0019 0.03 0.15 6.25 H25 0.0024 0.12 0.01 0.6 0.015 0.04 0.0025 0.05 0.17 5.67 H26 0.0027 0.1 0.01 0.63 0.018 0.04 0.0025 0.04 0.14 3.89 H27 0.0026 0.18 0.009 0.95 0.008 0.05 0.0022 0.08 0.26 16.3 H28 0.0017 0.05 0.0] 0.32 0.02 0.04 0.0022 0.01 0.06 1.5 H29 0.0023 0.15 0.01 0.62 0.005 0.05 0.0023 0.12 0.27 27 H30 0.0025 0.25 0.012 0.93 0.93 0.015 0.04 0.0024 0.29 0.54 18 H31 0.0017 0.]] 0 · 0]] 0.34 0.013 0.034 0.0029 0.043 0.018 0.15 5.88 H32 0.0016 0.09 0.01 0.32 0.036 0.0022 0.038 0.016 0.13 5.33 2.5 H33 0.0018 0.] 0.012 0.34 0.01 0.026 0.0025 0.043 0.022 0.016 0.14 7.15 2.22 Note: R-2 = 0.25 * vanadium / carbon, R-5 = manganese + copper, R-6 = 0.5 * (manganese + copper) / sulfur Table 16 46 200521249

Physical properties of sample number AS PN (number / mm2) Note YP (Mpa) TS (MPa) El (%) r-value (Im) △ r-va) ue (△ 0 AI (MPa) DBTT (° C) (μηι ) 265) 265 360 52 1.93 0.28 19 -70 0.05 4.5X108 IS Η2 255 358 53 2.09 0.28 14 -70 0.07 2.0X108 IS Η3 302 405 45 1.79 0.22 17 -60 0.06 4.2X108 IS Η4 289 392 46 1.70 0.29 19 -50 0.06 7.5X106 IS Η 5 350 452 37 1.63 0.21 13 -40 0.09 2.3X106 IS Η6 228 327 47 1.75 0.65 38 -50 0.38 8.3X103 cs Η7 282 385 39 1.59 0.55 45 -50 0.55 3.5X104 cs Η8 341 444 33 1.41 0.43 35 -40 0.61 2.3X104 cs Η9 256 358 51 2.32 0.29 19 -70 0.06 6.5X108 IS Η10 204 362 50 1.89 0.21 0 -60 0.06 5.5X108 IS HI 1 213 366 49 2.31 2.8 0 -60 0.07 5.〇ΧΙΟ8 IS H12 251 355 54 1.95 0.28 13 -80 0.07 4.9X108 IS H13 245 350 54] .97 0.28 20 -80 0.] 4 8.5X106 IS H14 296 405 45 1.73 0.25 13 -60 0.09 3.2X108 IS H15 305 405 44 1.79 0.22 18- 60 0.07 4.1X108 IS H16 365 465 37 1.55 0.2] 18 -50 0.] 7 2.2X106 IS H17 231 336 45 1.79 0.6] 42 -70 0.49 3.2X104 cs H18 279 382 40 1.63 0.5 7 40 -60 0.51 9.3X104 cs HI 9 331 445 32 1.37 0.22 42 -40 0.43 6.7X104 cs H20 260 362 52 2.35 0.28 26 -80 0.07 3.8X108 IS H21 208 360 50 1.89 0.23 0 -70 0.08 3.5X108 IS H22 203 352 51 2.21 0.27 0 -70 0.07 2.5X10x IS 47 200521249

---- H23 265 356 52 1.93 0.22 23 -80 0.06 5.9X108] S H24 258 352 54 1.95 0.29 27 -70 0.07 4.4X108 IS H25 298 395 45 1.62 0.22 22 -60 0.05 6.2X108 IS H26 302 405 46 1.58 0.20 23- 60 0.05 6.1X108] S H27 348 455 38 1.55 0.22 21 -50 0.06 2.2X106 IS H28 237 342 45 1.65 0.52 43 -70 0.35 4.2X104 cs H29 275 390 41 1.54 0.42 42 -60 0.55 7.3X104 cs H30 335 440 32 1.38 0.25 38 -40 0.42 5.7X104 cs | H31 258 359 5] 2.38 0.37] 9 -80 0.07 6.9X108 IS H32 210 352 52 — 1.9 0.22 0 -70 0.07 5.6X108 IS H33 204 349 52 2.21 0.36 0 -70 0.08 4.2X108 IS A., Chou intensity, extension, value: plasticity-anisotropy index, in-plane anisotropy index, AI = aging index, DBTT = used to study the brittleness of secondary work products, f sex conversion Temperature, AS = the average size of the Shen Dian objects, the number of chest redundant objects, the steel materials expected to be invented, cs = the comparative steel ^ [I 巳 例 3-3] A1N high strength shirt with the strengthening effect of Shen Dian ~ Shen; Dian Steel 10 The steel sheet shown in Table 17 was reheated to a temperature of 120 ° C and the condensed milk roll was continued. After the hot-rolled steel sheet is provided, the hot-milk steel sheet is cooled at a j-degree of -4 thief / minute, and is wound at 65 ° t. Then, it is cooled at a cross-section rate of 75%, and the rolled The base material is continuously annealed. After finishing rolling is performed, it is above the An transformation temperature and is continuously annealed by heating the steel sheet ° C at a rate of 1 second. Table] 7 48 15 200521249 sample 〇Carbon C Manganese Mη Phosphorus P Sulfur A] Nitrogen N Copper Cu Molybdenum Mo R V R-5 R-6 R-3 R-2 Number 0.003 0.03- 0.2 0.03- 0.06 0.003- 0.025 0.01- 0.1 0.005- 0.02 0.01- 0.2 0.01- 0.2 0.01- 0.2 0.3 2-20 ------- 1-5 1-20 1] 0.0023 0.05 0.04 0.015 0.032 0.0097 0.03--0.08 2.67 1.72-12 0.0018 0.1 0.042 0.012 0.042 0.0072 0.03- -0.13 5.42 3.03-13 0.0021 0.1 0.05 0.01 0.057 0.0080 0.08--0.18 9 ----- 3.71-14 0.0025 0.15 0.05 0.008 0.065 0.0075 0.1--0.25 15.63 4.51-15 0.0025 0.05 0.045 0.0Π 0.042 0.0072 0.01--0.06 1.76 3.03-16 0.0022 0.15 0.04 0.009 0.038 0.0014 0.05--0.2 11.1 14.1-17 0.0016 0.15 0.05 0.005 0.05 0.0070 0.2-- 0.35 35 —— · --- 3.71-] 8 0.0015 0.12 0.044 0.012 0.051 0.011 0.038 0.019-0.16 6.58 2.41-19 0.0018 0.1 0.04] 0.009 0.045 0.0095 0.039-0.02 0.14 7.72 2.46 2.78 110 0.0016 0.]] 0.042 0.01 0.042 0.01 0.049 0.018 0.016 0.16 7.95 2.18 2.5 Note: R-2 = 0.25 * vanadium / carbon, R-3 = 0.52 * aluminum / nitrogen, R-5 = manganese + copper, R-6 = 0.5 * (manganese + copper ) / Sulfur 5 Table 18 Sample number Physical properties AS (μπΊ) PN (number / mm2) Note YP (Mpa) TS (MPa) E] (%) r-value (l * m) △ r-value (△). ) A] (MPa) DBTT (° C) 11 246 352 54 1.96 0.29 22 -70 0.04 4.9X108 IS 12 252 356 53 1.94 0.28 25 -70 0.05 3.5X108 IS 13 250 348 50 1.89 0.32 27 &gt; 60 0.07 3.2X106 IS 14 255 350 48 1.86 0.35 22 -60 0.09 4.1X106 IS 15 243 340 43 1.68 0.39 36 -70 0.21 9.2X104 cs 16 223 328 48 1.89 0.32 27 -70 0.09 9.3X106 cs 17 238 342 43 1.72 0.34 38 -70 0.32 9.3X104 cs 49 200521249

5 Although the preferred embodiments of the present invention have been disclosed for the purpose of illustration, those skilled in the art will appreciate that the present invention is different without departing from the scope and concept of the present invention as disclosed in the scope of the appended patent application. Modifications, additions and substitutions are possible. [The diagram is simple and clear] Figures 1a to 1c are graphical representations, which illustrate the change of the carbon content relative to the size of a sink in a solid solution state in / grain; Figures 2a and 2b are illustrations of MnS Graphical representation of the size of the precipitate relative to the cooling rate 15; Figures 3a to 3c are graphical representations of the size of the CuS precipitate relative to the cooling rate; and Figures 4a and 4b are illustrations of MnS, CuS, and (Mn, Cu) Graphical representation of the size of the S deposits relative to the cooling rate. [Description of main component symbols] 50 20

Claims (1)

200521249 X. Scope of patent application: 1 · A cold-rolled steel sheet with anti-aging property and excellent plasticity, comprising: based on weight percentage, 0.03% or less carbon, 0.003 ~ 0 Sulfur at 03 ° / 〇, 〇ιι ～ 〇 ″% aluminum, 0.02% or less nitrogen, 502% or less phosphorus, 〇03 ~ 0 · 2 0 / At least one of manganese and 0.005 to 0.2% of copper ', and iron and other unavoidable impurities, where the steel sheet contains one of manganese, copper and sulfur, The composition satisfies at least one relationship: 0.58 * manganese / sulfur 21〇 and 1S0.5 * copper / sulfur ^ 10, and when the steel sheet includes both manganese and copper, the composition of 10 manganese, copper, and sulfur satisfies These relations: · Manganese + copper cut. 3 and 220.5 * (manganese + copper) / sulfur $ 2 0, and the precipitates MnS, CuS * (Mn, Cu) S have an average size of 0.2 μm or less . 2 * A cold-rolled steel sheet with aging resistance and excellent plasticity, which includes S. Based on weight 2: percentage '0 · 003 〇 / 〇 or less carbon, 〇0055 15 ~ 0. 03% Sulfur '0.01 ~ 0.1% aluminum, 0.02% or less nitrogen, 0.2% or less phosphorus, 0.05 ~ 0.2% manganese, and iron and other non-balancing Avoided impurities, in which the composition of manganese and sulfur satisfies the following relationship: 0.58 * manganese / sulfur do, and in which the% of precipitate "has an average size of 0.2 μm or less. 20 3 * As in the scope of patent application No. 2 The steel sheet according to item 2, wherein the steel sheet contains 0.015% or less of phosphorus. 4 · The steel sheet according to item 2 of the patent application scope, wherein the steel sheet contains 0.004% or less of nitrogen. 5 如The steel sheet applied for the item 2 of the patent scope in May, wherein the steel sheet contains 51 200521249 0.03 ~ 0.2% of stone gangue. 6 · If the steel sheet of the item 2 of the patent application scope, it further contains at least 0. ^ One of 0.8 ° / 〇 silicon and 0.2 to 2% chromium. 7. The steel sheet according to item 2 of the patent application scope, wherein the steel sheet contains 50 · 005 ~ 0 · 02% And 0.03 ~ 0.06% of phosphorus. 8. If the steel sheet of the scope of patent application No. 7, the composition of this Shao and nitrogen meet the relationship: κ 0.52 * aluminum / nitrogen S5. 9. The steel sheet according to any one of items 2 to 8, which further contains 0.001 to 0.2% of platinum. 10 1 10. As the steel sheet according to any one of claims 2 to 8, which further includes 〇 〇1 ～ 0. 2% 鈒. 11. For example, the steel sheet of the scope of application for patent No. 10, wherein the composition of vanadium and carbon satisfies the relationship: K0.25 * vanadium / carbon € 2. 12 · If the steel sheet in the scope of patent application No. 9 includes 15% of hunger. 13 · In the steel sheet in the scope of patent application No. 12, wherein the composition of vanadium and carbon satisfies the relationship : K0.25 * vanadium / carbon 20. 14 · A cold-rolled steel sheet with aging resistance and excellent plasticity, comprising: 0.0005 to 0.003% or less of carbon, based on weight percentage,- 0.003 ~ 〇025% of sulfur '〇〇〇〇〜〇〇〇〇〇 。。。, Lu, 002% or more, nitrogen, 0.2% or less of the dish, 〇001 ~ 〇 2% copper to And balance of iron and other unavoidable impurities, in which the composition of copper and sulfur satisfies the relationship: 150.5 * copper / sulfur, and where the precipitate cus has an average size of [] μη] or less. 52 200521249 For example, Shenqiao's patent covers 14 steel sheets, wherein the steel sheet contains 0. 015% or less scale. μ. The steel sheet according to item 14 of the patent application scope, wherein the steel sheet contains 0.004% or less of nitrogen. 5 10 15 20 如 If the steel sheet of the scope of application for item 14 is applied, the composition of copper and sulfur satisfies the relationship: KO · 5 * copper / sulfur magic. 8 The steel sheet of item 14 in the scope of the patent application, wherein the steel sheet contains 0.03 to 0.2% or less of a disk. 19. The steel sheet according to item 14 of the patent application scope, further comprising one of silicon of at least ~ 0.8 ° / 〇 and 0.2 to 12% of chromium. 〇 For example, the steel sheet of item No. 14 of Shen Weiyue's patent, wherein the steel sheet contains 0.005 ~ 2. 0% of nitrogen and 3 ~ 3% of stone dance. 21 · If the steel sheet of scope 20 of the patent application, the composition of aluminum and nitrogen satisfies the relationship: 1S0.52 * aluminum / nitrogen € 5. 22. The steel sheet according to any one of the claims 14 to 21, which further contains molybdenum of 0.001 to 0.2%. 23. The steel sheet according to any one of claims 14 to 21, which further contains 0.001 to 0.2% of vanadium. 24. If the steel sheet of scope 23 of the patent application, the composition of vanadium and carbon satisfies the relationship: ISO.25 * vanadium / carbon € 20. 25. The steel sheet according to item 22 of the patent application scope, which further comprises 0.001 to 0.2% of hunger. 26. If the steel sheet of item 25 of the patent application scope, wherein the composition of vanadium and carbon satisfies the relationship: 150.25 * 鈒 / carbon S20. 53 200521249 27 ·-A kind of cold-dried steel sheet with anti-aging property and excellent shapeability, which contains: ·· ~ 〜〇〇〇03% or less carbon, 0.003 ~ 0.025% sulfur '〇.01 ~ 〇8% Shao, 002% or less nitrogen, 0.2 〇 /. Or less dishes, 0.003 ~ 02% in Bangladesh, 0.05 ~ 0.2% copper, and iron and other unavoidable impurities of balance 'Among them, the composition of copper, copper and sulfur meets these relationships Formula: pot + copper cut. 3 and 2 cuts. 5 * (fierce + copper) / sulfur ', and where Shen Dian Wu ta, CuS and (Mn, Cu) S have an average size of 0.2 μΐΏ or less . 10 28. The steel sheet of claim 27, wherein the steel sheet contains 0.015 ° / 0 or less. 29. The steel sheet of claim 27, wherein the steel sheet contains 0.004% or less of nitrogen. 30. For the steel sheet material in the scope of patent application No. 27, the sinking object is 2 × 106 or more. 15 31 32 If the steel sheet of the 27th in the scope of the patent application, the composition of the ship and steel satisfies the relationship: 2 ^) · 5 * (manganese + steel ^ sulfur port. The claw is as the steel sheet in the 31st patent application. Material, wherein the mesh is 2 × 10 8 or more. 1 wherein the steel sheet contains at least 0.1 to 20 33. For the steel sheet of item 27 of the patent application scope, 0.03 to 0.2% or less of phosphorus. 34. For example, the steel sheet of item 27 of the scope of patent application, 0.8% of silicon and 0.2% to 1.2% of chromium, wherein the steel sheet contains 0.06% of a dish. 35 · For example, the steel in the 27th item of the patent application ranges from 0.005 to 0.02 ° / 〇 nitrogen and 〇03 ~ 54 200521249 36. The steel sheet in the 35th item of the patent application, wherein the composition of the name and atmosphere meets the relationship: K0.52 * Aluminum / Nitrogen 0. 37 · If the steel sheet of any one of the scope of patent application 27 to 36, it contains 0.01 ~ 0.2% molybdenum. 38 · If the scope of patent application is 27 to 36 The steel sheet of any one, further comprising 0.01 to 0.2% of vanadium. 39. The steel sheet of the 38th scope of the patent application, wherein the composition of the starvation and carbon satisfies the relationship : D25 · 25 * Vanadium / Carbon € 20. 40. For the steel sheet of item 39 in the scope of patent application, it also contains 0.001 to 0.2% of the hunger. 41. As in the scope of patent application The steel sheet of item 37, wherein the composition of the starvation and carbon satisfies the relationship ... 1S0.25 * 鈒 / carbon <20. 2 A cold-rolled steel sheet having anti-aging properties and excellent plasticity A method comprising the following steps: hot rolling a steel sheet with an Ar3 turning temperature or higher finishing roll to provide a hot rolled steel sheet, and after reheating the steel sheet to a temperature of 110 ° C or higher, The steel sheet contains, by weight percentage, 0.003% or less carbon, 0.005 to 0.03% sulfur, 0.001 to 01% aluminum, 0.02% or less nitrogen, 0.2 % Or less of phosphorus' 〇 · 〇5 ～ 〇 · 2 ° /. Clock, and the balance of iron and other unavoidable impurities, where the composition of manganese and sulfur meet the relationship: 0.58 * manganese / sulfur ^ 10; cooling the steel sheet at a speed of 200 ° C / minute or higher; winding the cooled steel sheet at a temperature of 700 ° C or lower; cold rolling the steel sheet and continuously annealing The cold-rolled steel sheet. 43. The method according to item 42 of the patent application, wherein the steel plate contains 0.05 55200521249% or less of a dish. 44. The method according to item 42 of the patent application, wherein the The steel sheet contains 0,004% or less of nitrogen. 45. The method according to item 42 of the scope of patent application, wherein the steel sheet contains 0.005 to 0.2% of phosphorus. 46. The method according to item 42 of the patent application scope, wherein the steel sheet further comprises at least one of 0.1 to 0.8% of silicon and 0.2 to 1.2% of chromium. 47. The method according to item 42 of the scope of patent application, wherein the steel plate contains 0.005 to 0.02% of nitrogen and 0.03 to 0.06% of stone dance. 10 It seems that the method according to the patent scope is requested, and the composition of the towel and nitrogen satisfies the relationship ... K0.52 * aluminum / nitrogen u. 49. The method according to any one of claims 42 to 48, wherein the steel sheet further contains 0.01 to 0.2% of molybdenum. 150. The method according to any one of claims 42 to 48 in the scope of Shen Qing's patent, wherein the steel sheet further contains 0.01 to 0.2% vanadium. 5: 1 • If the method is patent 5g, the method of item 5G, in which the composition of bribe and carbon satisfies the relationship: K0.25 * vanadium / carbon00. 52. The method of item 49 in the patent scope, such as the towel, wherein the steel plate further contains 0.01 to 0.2% vanadium. 0 53. The method of claim 52 in the scope of patent application, wherein the composition of the starvation and carbon satisfies the relationship ... K0.25 * vanadium / carbon 520. …-A method for manufacturing cold milk steel sheet with anti-aging properties and #heterosexual properties, which includes the following steps: ... Hot dry steel sheet, after adding 56 200521249 to heat the steel sheet to a temperature of 1100 ° C or higher, the steel sheet contains: 0.0005 to 0.003% carbon, 0.003 to 0.025% by weight Sulfur, 0.01 to 0.08% aluminum, 0.002% or less nitrogen, 0.2% or less dishes, 0.0% to 0% copper, and iron 5 for balance And other unavoidable impurities, in which the composition of copper and sulfur satisfies the relationship: H5 * copper / sulfur 〇; the cold section of the steel sheet at a speed of 300 it / min, at a temperature of 700 ° C Winding the cooled steel sheet at a lower temperature or lower; cold rolling the rolled steel sheet and continuously annealing the cold rolled steel sheet. 10 55. The method of claim 54 in which the steel sheet contains 0.015% or less of scale. 56 The method as claimed in claim 54 of the patent scope, wherein the steel sheet contains 0.004% or less nitrogen. 57 · 15 58 · The method of claim 54 in the scope of patent application, wherein the composition of copper and sulfur satisfies the relationship: 1S0.5 * copper / sulfur. For example, the method of claim M, wherein the steel sheet contains 0.003 to 0.2% or less of phosphorus. 59. For example, please refer to the 54th slave method in the patent scope, which includes at least 0.1 to 0.8% of Shi Xi and 02 to 12% of chromium. The method according to item 54 of the patent, wherein the steel sheet contains 0.05 to 0.002% of nitrogen and 0.03 to 0.006% of phosphorus. 61 · The method in Patent Application No. 6), where the composition of nitrogen depends on the relationship: 1 ^ 0.52 * aluminum / nitrogen y. 62. The method according to any one of claims 54 to 6], wherein the steel 57 200521249 plate further contains 0.01 to 0.2% molybdenum. 63. The method according to any one of claims 54 to 61, wherein the steel sheet further contains 0.01 to 0.2% of vanadium. 64 · The method according to item 63 of the scope of patent application, wherein the composition of rhenium and carbon 5 satisfies the relationship: 1S0.25 * vanadium / carbon € 20. 65 · If the method according to item 62 of the patent application scope, it further includes 0.01% to 0.2%. 66. The method according to item 65 of the scope of patent application, wherein the composition of vanadium and carbon satisfies the relationship: 1S0.25 * vanadium / carbon &lt; 20. 10 67 · —A method for manufacturing a cold-rolled steel sheet having aging resistance and excellent shapeability, comprising the steps of: hot-rolling a steel plate at an Ar3 transformation temperature or higher, to provide a hot-rolled steel Sheet, after reheating the steel plate to a temperature of 1100 ° C or higher, the steel plate contains 0.0005 ~ 0.003 ° / 〇 carbon in weight percentage, 0.003 15 ~ 0.025% white stone, 0.01 ~ 0.08%, 0 · 02% Nitrogen, 0.2% or less of phosphorus, 0.03 ~ 0.2% of manganese, 0.005 ~ 0.2% of copper, and iron and other unavoidable impurities of balance, among which the composition of manganese, copper and sulfur satisfies the following relationship: Copper ^ 0.3 and 2 &lt; 0.5 * (manganese + copper) / sulfur S20; cooling the steel sheet at a rate of 300 ° C / min; winding the cooled steel sheet at a temperature of 700 ° C or lower Cold rolling the coiled steel sheet and continuously annealing the cold rolled steel sheet. 68. The method of claim 67, wherein the steel sheet contains 0.015% or less of phosphorus. 58 200521249 69. For example, Taito ##, Wanfa ’of the patent application No. 67, wherein the steel plate contains 0.004% or less of nitrogen. 70. For example, the scope of the patent application (67), &lt; Wanfa ', wherein the number of the precipitates is 2x106 or more. 5 71 · 72 · If you apply for the item 67 in the scope of patent application, this &lt; Wanfa, in which the composition of manganese, copper and sulfur is full of ㈣ copper) _7. For example, if you apply for the method of item 71 of the special rhyme, the number of reductions is 2x108 or more. 10 15 20 73 · The 67th negative method according to the scope of patent application ', wherein the steel sheet contains 0.003 to 0.2% or less of phosphorus. I The method according to item 67 of the patent application scope, wherein the steel sheet further includes at least one of 0.1 to 0.8% of Shi Xi and 0.2 to 12%. The method according to item 67 of the patent application scope, wherein the steel sheet contains 0 005 to 0.02% nitrogen and 0.03 to 6% phosphorus. 76. The method of claim 75, wherein the nitrogen reduction composition satisfies the relationship: 式 α · 52 * aluminum / nitrogen. 77. The method according to any one of claims 67 to 76, wherein the steel sheet further contains 0.01 to 0.2% molybdenum. 78. The method according to any one of claims 67 to 76, wherein the steel sheet further contains 0.01 to 0.2% vanadium. 79. The method according to item 78 of the scope of patent application, wherein the composition of the starvation and carbon satisfies the relationship: 1S0.25 * vanadium / carbon &lt; 20. 80. The method according to item 77 of the patent application range, wherein the steel sheet further contains 0 to 0.2% vanadium. 59 200521249 81 · If the method in the scope of patent application is No. 80, the composition of vanadium and carbon satisfies the relationship: ISO.25 * vanadium / carbon 20. 60