US20040238083A1 - High strength cold rolled steel sheet with superior formability and weldability, and manufacturing method therefor - Google Patents

High strength cold rolled steel sheet with superior formability and weldability, and manufacturing method therefor Download PDF

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US20040238083A1
US20040238083A1 US10/481,354 US48135403A US2004238083A1 US 20040238083 A1 US20040238083 A1 US 20040238083A1 US 48135403 A US48135403 A US 48135403A US 2004238083 A1 US2004238083 A1 US 2004238083A1
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steel sheet
rolled steel
cold
steel
high strength
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Seung-Chul Baek
Sung-Ho Park
Choon-Sun Bea
Seong-Ju Kim
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Posco Holdings Inc
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C21D1/19—Hardening; Quenching with or without subsequent tempering by interrupted quenching
    • C21D1/20—Isothermal quenching, e.g. bainitic hardening
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0273—Final recrystallisation annealing
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/001—Austenite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/002—Bainite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0236—Cold rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0278—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving a particular surface treatment

Definitions

  • the present invention relates to a high strength cold-rolled steel sheet suitable for use in numerous structural parts of automobiles. More particularly, the present invention relates to a high strength cold-rolled steel sheet, which simultaneously provides a tensile strength of 70 to 90 kgf/mm 2 grade and is easily formed, thereby having increased impact energy absorption in case of collision and thus enhancing the safety of automobiles. The present invention also relates to a method for manufacturing the high strength cold-rolled steel sheet.
  • the steel utilizes work hardening based on a cold rolling process.
  • a steel is generally cold rolled and then recovery annealed. Therefore, the strength of the steel is increased due to its non-recrystallized structure.
  • the steel has a reduced added amount of alloy and is excellent in weldability, elongation is lowered and thus formability is deteriorated.
  • Composite structure steel with high strength in the form of sheets, is manufactured by cold rolling a steel, heating the cold-rolled steel sheet at a temperature above the austenitic phase transformation temperature (also called A 1 ) to form austenite and quenching, so that the austenite may be transformed to martensite or bainite.
  • a 1 austenitic phase transformation temperature
  • such a steel sheet must be rapidly cooled in a heat treatment process, there are disadvantages in that its manufacture is difficult and elongation is lowered.
  • Japanese Patent Laid-Open Publication No. Hei. 6-271942 and Hei. 7-090488 refer to Japanese Patent Laid-Open Publication No. Hei. 6-271942 and Hei. 7-090488.
  • Strain induced transformed steel has an increased elongation due to retained austenite present in the steel.
  • the reason why elongation is increased is that the retained austenite is transformed to high strength martensite upon deformation, thereby increasing the work hardening rate.
  • the steel contains retained austenite and its essential elements are known to be C, Si and Mn.
  • C serves to lower the transformation temperature of martensite and thus stabilize austenite
  • Si contributes to increasing the content of dissolved C in the retained austenite by suppressing formation of carbides.
  • Mn, along with C lowers the transformation temperature of martensite and increases the strength of the steel.
  • a conventional strain induced transformed steel has contained 1.5% or more Si to suppress formation of carbides, increase the volume fraction of retained austenite, and thus improve formability.
  • Si is high, weldability is deteriorated. Therefore, there are problems in that a defective proportion is increased in the course of welding steel sheets, as well as welding defects occur when such steel sheets are used in manufacturing structural parts of automobiles by spot welding.
  • the present invention has been made in view of the above problems of conventional strain induced transformed steel sheets, and it is an object of the present invention to provide a cold-rolled steel sheet with tensile strength of 70 to 90 kgf/mm 2 grade, in which formability and weldability are excellent and strength is increased, resulting from optimizing the composition of steel components such as C, Si, P and N, thereby reducing the thickness of structural parts of automobiles and thus making automobiles light in weight, and enhancing the safety of automobiles due to excellent impact energy absorption ability, when being applied as structural parts of automobiles.
  • FIGS. 1 a and 1 b are graphs showing phase diagrams of C-1.5Mn-1.5Si steel and C-1.5Mn-1.0Si-0.08P steel, respectively;
  • FIG. 2 is a graph showing the variations in mechanical properties depending on the content of P, and with or without N addition in 0.2C-1.0Si-1.5Mn steel;
  • FIG. 3 is a microstructure photograph showing suppression of growth of austenite using AlN precipitates.
  • FIG. 4 is a graph showing the variation in the volume fraction of austenite depending on an annealing temperature in steels, the steels differing only in the contents of C, Si and Mn.
  • C, Si and Mn are added as essential elements, so that retained austenite may be present in the steel, thereby increasing the elongation of the steel.
  • Si is generally added to 1.5% or more to suppress formation of carbides and thus increase the volume fraction of retained austenite.
  • the content of Si increases, the weldability of the steel sheet is lowered.
  • the present invention provides a cold-rolled steel sheet with excellent formability and weldability, comprising, in terms of percent by weight, 0.15 to 0.25% C, 0.5 to 1.5% Si, 1.0 to 2.0% Mn, 0.25% or less P, 0.020% or less S, 0.015 to 0.050% Al, 0.008 to 0.026% N, balance Fe and incidental impurities while satisfying a condition of 1.2 ⁇ Si[%]+50/8P[%] ⁇ 2.0.
  • the present invention provides a method for manufacturing a cold-rolled steel sheet with excellent formability and weldability, comprising the steps of:
  • C is an element required for reducing the transformation temperature of martensite, thereby to stabilize austenite. Therefore, retained austenite is formed at room temperature and thus elongation is increased.
  • C must be added in an amount of at least 0.15 weight % (hereinafter, simply referred to as %). However, if the C content exceeds 0.25%, weldability is deteriorated. As a result, such C content is unfavorable for welding of steel sheets and welding of structural parts of automobiles.
  • Si is an element which serves to suppress formation of carbides in an austempering process. If formation of carbides is suppressed by Si, the amount of dissolved C is increased and the dissolved C diffuses in retained austenite, so that the retained austenite is stabilized. On the other hand, because Si considerably reduces weldability, it is preferable to lower the content of Si so as to secure excellent welding of cold-rolled steel sheets for use as structural parts of automobiles.
  • the content of Si it is preferable to limit the content of Si to a range of 0.5 to 1.5%, so that formation of carbides may not only be effectively suppressed, but weldability may also be improved and surface defects of hot-rolled steel sheets caused by internal oxidation may also be reduced. More preferably, the Si content ranges from 0.5 to 1.2%.
  • Mn Manganese
  • 1.0 to 2.0% Mn is an element which increases the strength of steels and lowers the transformation temperature of martensite such as C, thereby stabilizing austenite.
  • the added amount of Mn is less than 1.0%, it is impossible to secure the above effects. If it exceeds 2.0%, there is a problem in that the transformation rate of ferrite is too slow and thus the amount of ferrite formed in a cooling process is reduced.
  • austenite which does not transform to ferrite in a cooling process is transformed to a high volume fraction of bainite at an austempering temperature. As a result, the strength of steel sheets is increased but elongation is reduced. Therefore, it is preferable to limit the content of Mn to a range of 1.0 to 2.0%.
  • P is an element required for strengthening ferrite such as Si and effectively suppresses formation of carbides.
  • P content exceeds 0.25%
  • P is excessively segregated in the center portion of grains in a slab manufacturing process, thereby fractures readily occurring in a continuous casting process.
  • P is excessively segregated at grain boundaries of steel products. As a result, grain boundaries are broken and thus ductility is reduced.
  • FIG. 1 shows a phase diagram of each of 1.5Mn-1.5Si steel and 1.5-1.0Si-0.08P steel. It can be seen from FIG. 1 that the appearances of the phase diagrams of the 1.5Mn-1.5Si steel and 1.5Mn-1.0Si-0.08P steel are the same.
  • FIG. 2 is a graph showing the variations in the mechanical properties depending on the content of P, and with or without the addition of N in 0.2C-1.0Si-1.5Mn steel. As shown in FIG. 2, where the added amount of Si is reduced to 1.0% and the content of P is increased, elongation is increased. In particular, it can be seen that elongation is greatly increased at a P content of 0.08%.
  • S is coupled with Mn to form MnS precipitates. Because inclusions such as MnS act as start points of cracks, it is advantage to reduce the amount of the precipitates. Therefore, it is preferable to limit the content of S to 0.020% or less.
  • Al is an element that is used as a deoxidizer. Al generally reacts with O in steels to form slag in a steel manufacturing process. Upon removal of the slag formed on molten steels, O is removed along with the slag. According to the present invention, Al is not only used for removing O in steels, but also for forming AlN precipitates and thus reducing the grain size of retained austenite, thereby to enhance elongation.
  • the grain size of retained austenite must be reduced in an annealing process. The growth of the grains is suppressed through formation of precipitates.
  • AlN precipitates are suitable. It is generally known that AlN cannot dissolve C and its size is much smaller than precipitates such as TiC, NbC and VC. If the amount of Al is less than 0.015%, the amount of the AlN precipitates is reduced, thereby not efficiently reducing the grain size of retained austenite. On the other hand, if the amount of Al exceeds 0.050%, coarse precipitates of AlN are formed thereby adversely affecting elongation. Therefore, it is preferable to limit the content of Al to a range of 0.015 to 0.050%.
  • N is an element required to form AlN.
  • N is generally added to less than 0.004% as the impurity element.
  • N should be added in an amount of at least 0.008%.
  • N is precipitated in the form of AlN, it is suitable for N to be added while taking into consideration the fact that atomic weight ratio of N to Al is 14 to 27. That is, where Al is added in an amount of 0.015 to 0.050%, it is preferable to limit N to a range of 0.008 to 0.026%. Under the above N range, an appropriate amount of AlN is formed, thereby reducing the grain size of retained austenite and thus increasing elongation, as shown in FIG. 2.
  • FIG. 3 shows that AlN precipitates suppress the diffusion of austenite grains. From FIG. 3, it can be seen that the AlN precipitates suppress the growth of austenite in an annealing process.
  • the high strength cold-rolled steel sheet with excellent formability and weldability of the present invention can be manufactured by hot rolling a steel with the composition mentioned previously, cold rolling the hot-rolled steel sheet, continuously annealing, quenching and cooling.
  • the manufacturing method of the cold-rolled steel sheet according to the present invention is characterized by controlling a continuous annealing process and austempering condition. Now, such features of the present invention will be described in detail.
  • a steel with the composition mentioned previously is hot rolled and cold rolled according to conventional methods to form a cold-rolled steel sheet.
  • the hot rolling and cold rolling conditions are given only for illustrative purposes and are not intended to be construed as a limitation thereof.
  • a steel with the composition mentioned previously is reheated at a high temperature in a hot rolling process.
  • the reheating temperature it is preferable to limit the reheating temperature to a range of 1,050 to 1,300° C.
  • a finishing hot rolling temperature it is preferable to limit a hot-rolled steel sheet formed in the hot rolling process to a range of 890 to 940° C.
  • a hot-rolled steel sheet formed in the hot rolling process is coiled. It is preferable to limit the coiling temperature to a range of 600 to 700° C.
  • the final hot-rolled steel sheet is pickled and then cold rolled.
  • a rolling reduction rate is preferably 40 to 70%.
  • the cold-rolled steel sheet is subjected to continuous annealing in a temperature range satisfying a condition of 563+651C[%]+42Si[%]+18Mn[%] ⁇ annealing temperature [° C.] ⁇ 850.
  • Austenite is formed by annealing at a continuous annealing furnace.
  • the austenite is cooled to an austempering temperature and then austempered to form bainite.
  • dissolved C diffuses in retained austenite, thereby to stabilize the retained austenite.
  • FIG. 4 is a graph showing the variation in the volume fraction of austenite depending on an annealing temperature while varying the contents of C, Si and Mn. From FIG. 4, it can be seen that where steel components are constant, the higher the annealing temperature is, the higher the volume fraction of retained austenite. Accordingly, where the annealing temperature is increased, maximum volume fraction of ferrite is formed, thereby the maximum amount of C being dissolved in austenite. While increasing the volume fraction of ferrite to the maximum level, pearlite must be completely dissolved. This is because a large amount of carbides in pearlite reduce the amount of C dissolved in austenite.
  • the volume fraction of austenite must be 19, 28 and 38% in steels having C contents of 0.1, 0.15 and 0.20%. Where austenite is formed exceeding the above values, the volume fraction of ferrite is reduced, thereby not forming a large amount of retained austenite.
  • an annealing temperature required for completely dissolving pearlite must satisfy a condition of the annealing temperature ⁇ 563+651C[%]+42Si[%]+18Mn[%].
  • the upper limit of the annealing temperature is set to 850° C. This is because if the annealing temperature exceeds 850° C., austenite is excessively formed.
  • the optimal annealing temperature range in the present invention is defined as the condition of 563+651C[%]+42Si[%]+18Mn[%] ⁇ annealing temperature [° C.] 850.
  • an annealing time it is preferable to set an annealing time to 50 seconds or more, thereby to form an appropriate amount of austenite at the annealing temperature.
  • the continuous annealed steel sheet is quenched to an austempering initiating temperature ranging from 400 to 450% and then cooled to a temperature ranging from 350 to 450° C. (austempering process). As a result, the transformation of austenite to pearlite is suppressed.
  • Quenching is carried out in a zone between the continuous annealing zone and the austempering initiating temperature.
  • a cooling rate is preferably about 20 to 100° C./sec.
  • some austenite formed in the annealing zone transforms to bainite and dissolved C diffuses in retained austenite, thereby the retained austenite being stabilized.
  • Total cooling times required for the quenching process (cooling to a temperature ranging from 400 to 450° C.) and then austempering process (cooling to a temperature ranging from 350 to 450° C.) are preferably 200 to 500 seconds.
  • An annealing time was 51 to 102 seconds and an austempering time was 300 seconds.
  • Table 2 describes the variations in the mechanical properties of cold-rolled steel sheets depending on the heat treatment condition.
  • TABLE 1 Lower limit of annealing Steel C Mn Si P S S—Al N Si + 50/8P temperature Remarks A1 0.20 1.51 1.05 0.072 0.010 0.035 0.0100 1.5 784 Invention A2 0.19 1.58 1.20 0.100 0.005 0.049 0.0140 1.8 766 Invention A3 0.20 1.48 0.90 0.080 0.003 0.034 0.0120 1.4 758 Invention A4 0.20 1.46 0.70 0.100 0.003 0.034 0.0110 1.3 749 Invention B1 0.10 2.35 1.44 0.011 0.009 0.035 0.0020 1.5 — Comparison B2 0.14 1.79 1.43 0.013 0.011 0.039 0.0036 1.5 — Comparison B3 0.20 1.33 1.70 0.011 0.009 0.037 0.0020 1.76 — Comparison B4 0.20 1.60 1.60 0.012 0.0050 0.040 0.01 1.67 — Comparison
  • the comparative examples 3-13 in which the composition of each steel is outside the range of the present invention, were poor in elongation and weldability.
  • the comparative examples 11-14 which were manufactured using B3 steel material with a Si content of more than 1.5%, all had poor weldability.
  • the comparative examples 1 and 2 have composition ranges within the present invention, but their annealing temperatures are outside the range of the present invention.
  • an annealing temperature was too low, thereby insufficient recrystallization of steel sheet being caused or carbides being incompletely dissolved. As a result, uniform retained austenite cannot be obtained, thereby elongation being reduced.
  • an annealing temperature was too high, thereby forming an acicular structure of retained austenite adversely affecting workability. As a result, elongation of final steel sheets was sharply reduced.
  • the present invention provides a high strength cold-rolled steel sheet with excellent formability due to high elongation.
  • a high strength steel sheet is suitable for use in structural parts of automobiles, thereby to enhance the safety of automobiles.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
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US10/481,354 2001-12-27 2002-06-20 High strength cold rolled steel sheet with superior formability and weldability, and manufacturing method therefor Abandoned US20040238083A1 (en)

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KR2001/85539 2001-12-27
KR1020010085539A KR100554753B1 (ko) 2001-12-27 2001-12-27 성형성 및 용접성이 우수한 고강도 냉연강판과 그 제조방법
PCT/KR2002/001167 WO2003056041A1 (fr) 2001-12-27 2002-06-20 Feuille d'acier de haute resistance laminee a froid dotee de caracteristiques superieures de formabilite et de soudabilite, et procede de fabrication

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TWI494447B (zh) * 2011-07-29 2015-08-01 Nippon Steel & Sumitomo Metal Corp High-strength steel sheet excellent in formability, high-strength zinc plated steel sheet and the like (2)
CN105154763A (zh) * 2015-09-24 2015-12-16 华北理工大学 低碳硅锰系贝氏体高强钢及其生产方法
CN108441604A (zh) * 2018-01-24 2018-08-24 易觉汽车科技（上海）有限公司 一种汽车零部件局部变强度设计方法
CN117127099A (zh) * 2023-04-28 2023-11-28 鞍钢股份有限公司 1300MPa超高强塑冷轧Mn-TRIP钢及其制备方法

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* Cited by examiner, † Cited by third party
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JP5165236B2 (ja) * 2006-12-27 2013-03-21 新日鐵住金ステンレス株式会社 衝撃吸収特性に優れた構造部材用ステンレス鋼板
KR101129757B1 (ko) * 2009-03-26 2012-03-23 현대제철 주식회사 박슬라브 에지부 톱날형 결함 저감방법
BR112015002312A2 (pt) 2012-08-06 2017-07-04 Nippon Steel & Sumitomo Metal Corp chapa de aço laminada a frio e método para produção da mesma, e elememento conformado por estampagem a quente
CN103276303A (zh) * 2013-06-07 2013-09-04 南京钢铁股份有限公司 一种高强度矿用链条钢及其制备方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5919415A (en) * 1996-12-31 1999-07-06 Ascometal Steel and process for the manufacture of a steel component formed by cold plastic deformation
US6692584B2 (en) * 2000-04-27 2004-02-17 Jfe Steel Corporation High tensile cold-rolled steel sheet excellent in ductility and in strain aging hardening properties, and method for producing the same

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0238532A (ja) * 1988-07-29 1990-02-07 Kobe Steel Ltd 冷延高張力薄鋼板の製造方法
JPH09194935A (ja) * 1996-01-10 1997-07-29 Toyo Kohan Co Ltd ばね性に優れたガスケット材用冷延鋼板の製造法およびガスケット材
JPH10259448A (ja) * 1997-03-21 1998-09-29 Kobe Steel Ltd 静的吸収エネルギー及び耐衝撃性に優れた高強度鋼板並びにその製造方法
JP3448454B2 (ja) * 1997-04-10 2003-09-22 新日本製鐵株式会社 表面性状と成形性にすぐれた高強度冷延鋼板とその製造方法
JP3727151B2 (ja) * 1997-09-04 2005-12-14 Ｊｆｅスチール株式会社 ドラム缶用冷延鋼板およびその製造方法ならびに鋼製高強度ドラム缶
KR100328044B1 (ko) * 1997-11-04 2002-05-10 이구택 3상복합조직고강도냉연강판의제조방법
JP3401427B2 (ja) * 1998-03-12 2003-04-28 株式会社神戸製鋼所 耐衝撃性に優れた高強度鋼板
JPH11343538A (ja) * 1998-05-29 1999-12-14 Kawasaki Steel Corp 高密度エネルギービーム溶接に適した冷延鋼板およびその製造方法
JP3424619B2 (ja) * 1999-09-16 2003-07-07 住友金属工業株式会社 高張力冷延鋼板及びその製造方法
KR100415667B1 (ko) * 1999-12-20 2004-01-31 주식회사 포스코 충격흡수성 및 성형성이 우수한 고강도 냉연강판 및 그제조방법
JP4839527B2 (ja) * 2000-05-31 2011-12-21 Ｊｆｅスチール株式会社 歪時効硬化特性に優れた冷延鋼板およびその製造方法
KR100470652B1 (ko) * 2000-12-20 2005-03-07 주식회사 포스코 성형성이 우수한 고강도 냉연강판의 제조방법

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5919415A (en) * 1996-12-31 1999-07-06 Ascometal Steel and process for the manufacture of a steel component formed by cold plastic deformation
US6692584B2 (en) * 2000-04-27 2004-02-17 Jfe Steel Corporation High tensile cold-rolled steel sheet excellent in ductility and in strain aging hardening properties, and method for producing the same

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100227192A1 (en) * 2009-03-09 2010-09-09 The Hong Kong Polytechnic University Composite steel plate and method of making a composite steel plate
US8752752B2 (en) * 2009-03-09 2014-06-17 Hong Kong Polytechnic University Method of making a composite steel plate
TWI494447B (zh) * 2011-07-29 2015-08-01 Nippon Steel & Sumitomo Metal Corp High-strength steel sheet excellent in formability, high-strength zinc plated steel sheet and the like (2)
US9896751B2 (en) 2011-07-29 2018-02-20 Nippon Steel & Sumitomo Metal Corporation High strength steel sheet and high strength galvanized steel sheet excellent in shapeability and methods of production of same
CN104630641A (zh) * 2014-12-11 2015-05-20 武汉钢铁(集团)公司 800MPa级高强度高塑性低碳中锰钢及其制造方法
CN105154763A (zh) * 2015-09-24 2015-12-16 华北理工大学 低碳硅锰系贝氏体高强钢及其生产方法
CN108441604A (zh) * 2018-01-24 2018-08-24 易觉汽车科技（上海）有限公司 一种汽车零部件局部变强度设计方法
CN117127099A (zh) * 2023-04-28 2023-11-28 鞍钢股份有限公司 1300MPa超高强塑冷轧Mn-TRIP钢及其制备方法

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