[go: up one dir, main page]

US20100221138A1 - High-strength composite steel sheet having excellent moldability and delayed fracture resistance - Google Patents

High-strength composite steel sheet having excellent moldability and delayed fracture resistance Download PDF

Info

Publication number
US20100221138A1
US20100221138A1 US12/303,566 US30356607A US2010221138A1 US 20100221138 A1 US20100221138 A1 US 20100221138A1 US 30356607 A US30356607 A US 30356607A US 2010221138 A1 US2010221138 A1 US 2010221138A1
Authority
US
United States
Prior art keywords
less
ferrite
steel sheet
strength
strength composite
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/303,566
Other languages
English (en)
Inventor
Michiharu Nakaya
Yoichi Mukai
Koichi Sugimoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kobe Steel Ltd
Shinshu TLO Co Ltd
Original Assignee
Kobe Steel Ltd
Shinshu TLO Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kobe Steel Ltd, Shinshu TLO Co Ltd filed Critical Kobe Steel Ltd
Assigned to KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.) reassignment KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.) ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MUKAI, YOICHI, NAKAYA, MICHIHARU, SUGIMOTO, KOICHI
Publication of US20100221138A1 publication Critical patent/US20100221138A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • 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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • 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
    • 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
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
    • 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
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • 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
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • 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
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese

Definitions

  • the present invention relates to a high-strength composite steel sheet which has a tensile strength of 980 MPa or higher class as well as excellent formability and excellent anti-delayed fraction property, and also has excellent spot-weldability and is useful as automotive structural parts (body flame members such as pillar, member and reinforcement; bumper, door guard bar, sheet parts, suspension parts, and other reinforcing members).
  • delayed fracture is a phenomenon in which hydrogen in the corrosion environment or atmosphere is diffused and accumulated at dislocations, vacancies and grain boundaries in the structure of steel materials, especially high-strength steel sheets thereby causing embrittlement of the materials, leading to fracture when stress is applied. Therefore, delayed fracture exerts a severe influence on ductility and toughness of steel materials.
  • Non-Patent Document 1 discloses a steel sheet in which a bore expansion property (i.e. stretch flangeability) is enhanced while ensuring a high strength by constituting the metal structure with a composite structure which mainly contains bainitic ferrite and also contains lath-type residual austenite.
  • a tensile strength (TS) becomes a tensile strength of 980 MPa or higher class
  • this steel sheet shows TS ⁇ El as an indicator of the strength (TS) and ductility (El) of 9,000 to 10,300 at most and therefore it is hardly to say that the steel sheet is satisfactory.
  • a maximum heating temperature is about 900° C. and a heating time is 5 minutes or less.
  • it is required to cool to a temperature within the range from 350 to 400° C. in a salt bath after annealing at 950° C. for 1,200 seconds, and thus this method is not suited for the practical operation.
  • Patent Document 1 elongation of about 20% and stretch flangeability ( ⁇ ) of 55% are attained while ensuring a tensile strength of 980 MPa or higher by constituting a matrix phase with a structure composed mainly of bainitic ferrite and 3% or more of residual austenite.
  • ⁇ stretch flangeability
  • the addition of expensive alloy elements such as Mo, Ni and Cu is indispensable and it leaves a room for improvement in cost.
  • Patent Document 2 high-level elongation and stretch flangeability are attained by constituting a matrix structure with tempered martensite and ferrite and adjusting the occupancy ratio of residual austenite within the range from 5 to 30%.
  • a microstructure before annealing is important so as to obtain the required metal structure using this technique, it is necessary to perform continuous annealing or annealing twice or more after incorporating a proper metal structure by reeling up at low temperature during a hot rolling step.
  • severe restriction is added to the thickness and thickness tolerance.
  • continuous annealing is performed twice, although there is no restriction on the thickness, the number of steps increases when compared with the case of a conventional method and thus cost-up cannot be avoided.
  • Patent Document 3 discloses steel sheets having enhanced total elongation and stretch flangeability by mainly constituting a matrix structure with tempered bainite.
  • a study is mainly made on steels having a tensile strength of 900 MPa class in this steel type, delayed fracture, which is caused in steels having a tensile strength of 980 MPa or higher class, is not sufficiently studied.
  • Non-Patent Document 1 ISIJ International, Vol. 40 (2000), No. 9, pp. 920 to 926
  • Patent Document 1 Japanese Unexamined Patent Publication (Kokai) No. 2004-332099
  • Patent Document 2 Japanese Unexamined Patent Publication (Kokai) No. 2003-171735
  • Patent Document 3 Japanese Unexamined Patent Publication (Kokai) No. 2002-309334
  • the present invention has been made in view of the above-mentioned prior arts, and an object thereof is to provide a high-strength composite steel sheet which has a tensile strength of 980 MPa class suited for use as automotive structural parts and has excellent formability (stretch flangeability), and also has excellent spot-weldability and excellent anti-delayed fraction property, without adding expensive alloying elements such as Mo, Ni and Cu.
  • the high-strength composite steel sheet of the present invention which could achieve the above object, is a high-strength composite steel sheet having excellent formability and anti-delayed fraction property, comprising a steel satisfying C: 0.10 to 0.25%, Si: 1.0 to 3.0%, Mn: 1.5 to 3.0%, P: 0.15% or less (excluding 0%), S: 0.02% or less (excluding 0%), Al: 0.4% or less (excluding 0%), and comprising a remnant made from iron and unavoidable impurities, wherein the contents of Si, Al and Mn satisfy the relationship of the following formula (I):
  • a microstructure in a longitudinal section comprises, by an occupancy ratio based on the entire structure
  • the high-strength composite steel sheet of the present invention optionally contains, in addition to the above elements, Ti: 0.15% or less (excluding 0%) and/or Nb: 0.1% or less (excluding 0%), or optionally contains Ca: 30 ppm or less (excluding 0%) and/or REM: 30 ppm or less (excluding 0%) as other elements.
  • the high-strength composite steel sheet of the present invention has a tensile strength of 980 MPa or higher so as to more effectively make use of its high strength.
  • the present invention by specifying chemical components of the steel material as described above, particularly controlling a ratio (Si+Al)/Mn or a ratio (Si+Al)/(Mn+Cr), and constituting the metal structure with a composite structure which mainly contains bainitic ferrite (BF) and also contains polygonal ferrite (PF) and residual austenite (residual ⁇ ), it is possible to provide a composite steel sheet which has good formability (elongation-stretch flangeability) and also excellent spot-wedability and anti-delayed fraction property while ensuring a tensile strength of 980 MPa or higher class at cheap price.
  • BF bainitic ferrite
  • PF polygonal ferrite
  • residual austenite residual austenite
  • FIG. 1 is a diagram for explaining a heat pattern of a heat treatment employed in Test Example.
  • the present inventors have focused on a TRIP steel sheet (Transformation Induced Plasticity) having a tensile strength of 980 MPa or higher class, containing bainitic ferrite as a matrix phase, and intensively studied by paying attention to the form of the second phase in the metal structure and chemical components, especially Si, Al and Mn (and/or Cr) so as further improve formability, spot-weldability and anti-delayed fraction property.
  • TRIP steel sheet Transformation Induced Plasticity
  • the present inventors have intensively studied about an influence of the contents of Si, Al, Mn and Cr in steel components and the metal structure on the strength, formability, spot-weldability and anti-delayed fracture characteristics. As a result, they have confirmed that a high-strength composite steel sheet having high performances, which achieve the above object, can be obtained by controlling the occupancy ratio of bainitic ferrite in the metal structure, controlling the occupancy ratios of polygonal ferrite and residual ⁇ and controlling an average grain size of the polygonal ferrite to a specific value or less using a steel material having specific component composition described above. Thus, the present invention has been completed.
  • C is an element which is indispensable so as to ensure a high strength and residual ⁇ , and is an important element so as to incorporate a sufficient amount of C in a ⁇ phase thereby retaining a desired amount of the ⁇ phase at room temperature.
  • the content of C In order to effectively exert such an effect, the content of C must be 0.10% or more, preferably 0.12% or more, and 0.15% or more. When the content of C is too large, a severe adverse influence is exerted on spot-weldability, and thus the upper limit was 0.25% in view of security of spot-weldability.
  • the C content is preferably 0.23% or less, and more preferably 0.20% or less.
  • Si is an essential element which effectively serves as a solution-hardening element and also suppresses formation of a carbide as a result of decomposition of residual ⁇ .
  • the content of Si must be 1.0% or more, and preferably 1.2% or more. Since the effect is saturated at 3.0% and problems such as deterioration of spot-weldability and hot shortness arise when the content is more than the above value, the content may be suppressed to 3.0% or less, and preferably 2.5% or less.
  • Mn is an element required to suppress formation of excess polygonal ferrite thereby forming a structure composed mainly of bainitic ferrite. Also it is an important element required to stabilize ⁇ thereby ensuring desired residual ⁇ .
  • the occupancy ratio of Mn is at least 1.5% or more, and preferably 2.0% or more.
  • the content is suppressed to 3.0% at most, and preferably 2.5% or less.
  • Al is a useful element so as to suppress formation of a carbide thereby ensuring residual ⁇ similar to Si.
  • the content should be suppressed to 0.4% at most, and preferably 0.2% or less.
  • Cr Since Cr has the effect of suppressing formation of polygonal ferrite thereby enhancing the strength, it can be optionally added. However, when it is excessively added, an adverse influence may be exerted on formation of the target metal structure in the present invention. Therefore, the content should be suppressed to 1.0% at most.
  • anti-delayed fraction property is improved by controlling the ratio of the elements within a proper range. Details of this reason are not sure, but are considered as follows. That is, Mn promotes delayed fracture by decreasing a grain boundary strength by grain boundary segregation and also promotes formation of voids serving as the starting point of delayed fracture upon working, whereas, Si and Al have the effect of increasing a tolerance amount of hydrogen which induces delayed fracture. Therefore, it is considered that anti-delayed fraction property varies by a ratio of both elements.
  • Nb 0.1% or less
  • Ti 0.15% or less
  • these elements have the effect of enhancing toughness by refinement of the metal structure, these elements can be optionally added in a small amount. However, further effect is not obtained to cause cost-up even if they are added in the amount of more than the upper limit, therefore it is wasteful.
  • Ca and REM have the effect of enhancing stretch flangeability by adding in a small amount and therefore they may be optionally added in a small amount. Since the effect is saturated at about 0.01%, it is wasteful even if they are added in a larger amount.
  • Bainitic ferrite has not only the effect of easily achieving a high strength because of somewhat high dislocation density, but also the effect of decreasing a difference in hardness between bainitic ferrite and the second phase thereby enhancing stretch flangeability.
  • Bainitic ferrite is a structure which is useful for enhancing anti-delayed fraction property. This reason is considered that bainitic ferrite does not contain or contains little cementite serving as the starting point of delayed structure, and has a high hydrogen absorbing effect because of a lot of dislocations. In order to effectively exert these effects, it is necessary that the content of bainitic ferrite exist at 50% or more. The content is more preferably 60% or more.
  • the bainitic ferrite is different from a bainite structure in that the structure does not include carbides, and is also different from a polygonal ferrite structure having a lower bainite structure which does not contain or contains little dislocation, or a quasi-polygonal ferrite structure having a lower bainite structure such as fine subgrain. These differences can be easily identified by TEM (Transmission Electron Microscope) observation.
  • a steel sheet having a tensile strength of 980 MPa or higher class comprising bainite ferrite (BF) as a matrix phase contains a predetermined amount of polygonal ferrite having an average grain size described below, elongation is further improved.
  • the content of polygonal ferrite must be contained at 5% or more so as to exert such an effect.
  • Preferred occupancy ratio of polygonal ferrite is 10% or more and 30% or less.
  • Average Grain Size of Polygonal Ferrite 10 ⁇ m or less
  • the average grain size of polygonal ferrite must be 10 ⁇ m or less by the following reason. That is, refinement of ferrite enables uniform dispersion of the second phase, and thus both stretch flangeability and strength are enhanced and also anti-delayed fraction property is improved. This reason is considered that refinement of ferrite enables trap of hydrogen at the ferrite grain boundary and suppression of concentration of hydrogen at a dangerous site.
  • the average grain size of polygonal ferrite as used herein means an average of an equivalent circle diameter (diameter of a circle having the same area) of polygonal ferrite.
  • Residual ⁇ has the effect of promoting hardening of the deformed part by transforming into martensite when the material is deformed by application of strain, and thus preventing strain concentration (TRIP effect). It is necessary that the content of the residual ⁇ is 5% or more so as to effectively exert such the effect. There is no restriction on the upper limit of the amount of the residual ⁇ . Since a large amount of C is required so as to form excessive residual ⁇ , it becomes difficult to reconcile with spot-weldability and workability, especially stretch flangeability. Therefore, the content is preferably suppressed to about 30% or less.
  • martensite, bainite and pearite can exist as the other balance structure.
  • the contents of these other structures are preferably suppressed to 5% or less so as not to exert an adverse influence on the above operations and effects.
  • Heating Temperature upon Annealing Ac 3 +10° C. or higher
  • the heating temperature upon annealing may be adjusted to “Ac 3 +10° C. or higher” so as to suppress formation of polygonal ferrite.
  • more preferred heating temperature is “Ac 3 +30° C. or higher”.
  • the cooling rate is preferably 25° C./sec or higher, and more preferably 30° C./sec or higher, so as to suppress the amount of polygonal ferrite to a certain amount of less according to each component system.
  • the temperature at which quenching after annealing is terminated should be controlled to the temperature at which fine polygonal ferrite is formed or lower, and is preferably 650° C. or lower, and more preferably 600° C. or lower.
  • the quenching termination temperature becomes higher, coarse polygonal ferrite is formed and it becomes impossible to achieve the object of the present invention.
  • the quenching termination temperature should be about 360° C. or higher, and more preferably up to 400° C.
  • the holding temperature is preferably within the range from 360 to 440° C. so as to obtain the metal structure of the present invention.
  • the retention time is preferably one minute or more. It is necessary that the holding temperature is lower than the quenching termination temperature. After passing through the temperature range where fine ferrite is likely to be formed, the material is transferred to a bainitic ferrite transformation temperature range.
  • a composite steel sheet having a high strength of 980 MPa or higher class, good spot-weldabaility and anti-delayed fraction property can be provided at cheap price by using a steel material having specified chemical components as described above and employing proper heat treatment conditions including cooling conditions and holding conditions thereby ensuring a predetermined metal structure.
  • each cold rolled sheet was heated to a predetermined annealing temperature, held at the same temperature for 180 seconds, cooled to a predetermined cooling termination temperature at a predetermined cooling rate, held at a predetermined temperature for 6 minutes and then furnace-cooled.
  • the metal structure of the resultant cold rolled steel sheet was confirmed by the following method and each test steel sheet was subjected to a tension test, a bore expansion test, a spot-welding test and an anti-delayed fracture test. The results collectively shown in Table 3 were obtained.
  • Polygonal ferrite is identified by a micrograph taken by A described above. Since etched residual ⁇ and etched martensite show a white color, whereas, etched PF shows a gray color, PF can be identified. After tracing the periphery of polygonal ferrite in the SEM micrograph taken by B described above, an equivalent circle diameter was calculated from the resultant trace image by image analysis. An average of the resultant equivalent circle diameter was taken as an average grain size of the polygonal ferrite.
  • the occupancy ratio was calculated by subtracting an amount of polygonal ferrite, an amount of residual ⁇ , and balance of martensite (M) and bainite (B) from 100%.
  • Thickness of test material 1.2 mm
  • Electrode Dome radius type (tip diameter: 6 mm)
  • Tests Nos. 1 to 10 and 16 are Examples which satisfy all defined features of the present invention. All steel materials have a tensile strength of 980 MPa or higher class and have good formability evaluated by strength ⁇ elongation characteristics and strength ⁇ stretch flangeability characteristics, and also have good spot-weldability and anti-delayed fraction property.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
US12/303,566 2006-06-05 2007-06-04 High-strength composite steel sheet having excellent moldability and delayed fracture resistance Abandoned US20100221138A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2006-156442 2006-06-05
JP2006156442A JP4974341B2 (ja) 2006-06-05 2006-06-05 成形性、スポット溶接性、および耐遅れ破壊性に優れた高強度複合組織鋼板
PCT/JP2007/061301 WO2007142197A1 (ja) 2006-06-05 2007-06-04 成形性、耐遅れ破壊性に優れた高強度複合組織鋼板

Publications (1)

Publication Number Publication Date
US20100221138A1 true US20100221138A1 (en) 2010-09-02

Family

ID=38801448

Family Applications (1)

Application Number Title Priority Date Filing Date
US12/303,566 Abandoned US20100221138A1 (en) 2006-06-05 2007-06-04 High-strength composite steel sheet having excellent moldability and delayed fracture resistance

Country Status (6)

Country Link
US (1) US20100221138A1 (ko)
JP (1) JP4974341B2 (ko)
KR (1) KR20090016500A (ko)
CN (1) CN101460646B (ko)
GB (1) GB2452230B (ko)
WO (1) WO2007142197A1 (ko)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2491958A (en) * 2011-06-13 2012-12-19 Kobe Steel Ltd Steel sheet with a tensile strength of at least 1180 MPa
US8480819B2 (en) 2010-01-29 2013-07-09 Kobe Steel, Ltd. High-strength cold-rolled steel sheet excellent in workability and method for manufacturing the same
US8932414B2 (en) 2010-03-24 2015-01-13 Kobe Steel, Ltd. High-strength steel sheet with excellent warm workability
US20150184274A1 (en) * 2012-07-12 2015-07-02 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High-strength hot-dip galvanized steel sheet having excellent yield strength and formability, and manufacturing method therefor
US9194032B2 (en) 2011-03-02 2015-11-24 Kobe Steel, Ltd. High-strength steel sheet with excellent deep drawability at room temperature and warm temperature, and method for warm working same
WO2016001702A1 (en) * 2014-07-03 2016-01-07 Arcelormittal Method for producing a high strength coated steel sheet having improved strength, ductility and formability
WO2016001700A1 (en) * 2014-07-03 2016-01-07 Arcelormittal Method for producing a high strength steel sheet having improved strength, ductility and formability
US9322088B2 (en) 2012-12-12 2016-04-26 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High-strength steel sheet and method for producing the same
EP3009527A4 (en) * 2013-08-09 2016-07-06 Jfe Steel Corp HIGHLESS COLD-ROLLED STEEL PLATE AND METHOD FOR THE PRODUCTION THEREOF
US20160355920A1 (en) * 2011-03-31 2016-12-08 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High-strength steel sheet excellent in workability and manufacturing method thereof
US9631266B2 (en) 2012-03-29 2017-04-25 Kobe Steel, Ltd. Method for manufacturing high-strength cold-rolled steel sheet with outstanding workability
US9657381B2 (en) 2011-08-17 2017-05-23 Kobe Steel, Ltd. High-strength steel sheet having excellent room-temperature formability and warm formability, and warm forming method thereof
US9890437B2 (en) 2012-02-29 2018-02-13 Kobe Steel, Ltd. High-strength steel sheet with excellent warm formability and process for manufacturing same
US10066274B2 (en) 2013-09-27 2018-09-04 Kobe Steel, Ltd. High-strength steel sheet having excellent ductility and low-temperature toughness, and method for producing same
US10544489B2 (en) 2010-11-18 2020-01-28 Kobe Steel, Ltd. Highly formable high-strength steel sheet, warm working method, and warm-worked automobile part
US10995383B2 (en) 2014-07-03 2021-05-04 Arcelormittal Method for producing a high strength coated steel sheet having improved strength and ductility and obtained sheet
US11555226B2 (en) 2014-07-03 2023-01-17 Arcelormittal Method for producing a high strength steel sheet having improved strength and formability and obtained sheet
US12054799B2 (en) 2015-12-21 2024-08-06 Arcelormittal Method for producing a high strength steel sheet having improved ductility and formability, and obtained steel sheet
US12084738B2 (en) 2015-12-21 2024-09-10 Arcelormittal Method for producing a steel sheet having improved strength, ductility and formability

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4998756B2 (ja) * 2009-02-25 2012-08-15 Ｊｆｅスチール株式会社 加工性に優れた高強度溶融亜鉛めっき鋼板およびその製造方法
EP2831299B2 (en) 2012-03-30 2020-04-29 Voestalpine Stahl GmbH High strength cold rolled steel sheet and method of producing such steel sheet
US10106874B2 (en) 2012-03-30 2018-10-23 Voestalpine Stahl Gmbh High strength cold rolled steel sheet
ES2614465T3 (es) * 2012-07-10 2017-05-31 Thyssenkrupp Steel Europe Ag Producto plano de acero laminado en frío y procedimiento para su fabricación
JP5860373B2 (ja) * 2012-09-20 2016-02-16 株式会社神戸製鋼所 降伏強度と温間成形性に優れた高強度溶融亜鉛めっき鋼板およびその製造方法
CN104513927B (zh) * 2014-12-19 2017-04-05 宝山钢铁股份有限公司 一种抗拉强度800MPa级高强度高韧性钢板及其制造方法
JP6601253B2 (ja) * 2016-02-18 2019-11-06 日本製鉄株式会社 高強度鋼板
MX2020008637A (es) * 2018-03-30 2020-09-21 Nippon Steel Corp Lamina de acero.
CN110777297B (zh) * 2019-10-12 2022-07-05 河钢股份有限公司 一种高扩孔性高拉延性高强度钢板及其制造方法

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6280538B1 (en) * 1998-03-12 2001-08-28 Kabushiki Kaisha Kobe Seiko Sho Hot rolled high strength steel sheet with excellent formability
US20050150580A1 (en) * 2004-01-09 2005-07-14 Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) Ultra-high strength steel sheet having excellent hydrogen embrittlement resistance, and method for manufacturing the same
US20050161134A1 (en) * 2004-01-28 2005-07-28 Shinshu Tlo Co., Ltd. High strength and low yield ratio cold rolled steel sheet and method of manufacturing the same
US20050247378A1 (en) * 2004-04-22 2005-11-10 Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) High-strength cold rolled steel sheet having excellent formability, and plated steel sheet
US20060137769A1 (en) * 2004-12-28 2006-06-29 Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) High strength thin steel sheet having high hydrogen embrittlement resisting property and high workability
US20060137768A1 (en) * 2004-12-28 2006-06-29 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High strength thin steel sheet having high hydrogen embrittlement resisting property
US7090731B2 (en) * 2001-01-31 2006-08-15 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High strength steel sheet having excellent formability and method for production thereof
US7371294B2 (en) * 2004-02-02 2008-05-13 Kobe Steel, Ltd. High-strength cold-rolled steel sheet having outstanding elongation and superior stretch flange formability and method for production therof
US7413617B2 (en) * 2004-12-21 2008-08-19 Kabushiki Kaisha Kobe Seiko Sho Composite structure sheet steel with excellent elongation and stretch flange formability
US20080251160A1 (en) * 2005-03-30 2008-10-16 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd) High-Strength Cold-Rolled Steel Sheet Excellent in Uniform Elongation and Method for Manufacturing Same
US20080251161A1 (en) * 2005-03-30 2008-10-16 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High Strength Cold Rolled Steel Sheet and Plated Steel Sheet Excellent in the Balance of Strength and Workability
US20090014095A1 (en) * 2006-03-31 2009-01-15 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High-strength cold rolled steel sheet excelling in chemical treatability

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4266343B2 (ja) * 2003-11-11 2009-05-20 株式会社神戸製鋼所 成形性に優れた高強度熱延鋼板
JP4412727B2 (ja) * 2004-01-09 2010-02-10 株式会社神戸製鋼所 耐水素脆化特性に優れた超高強度鋼板及びその製造方法
JP4411221B2 (ja) * 2004-01-28 2010-02-10 株式会社神戸製鋼所 伸び及び伸びフランジ性に優れた低降伏比高強度冷延鋼板およびめっき鋼板並びにその製造方法
JP4506971B2 (ja) * 2004-04-22 2010-07-21 株式会社神戸製鋼所 成形性に優れた高強度冷延鋼板およびめっき鋼板

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6280538B1 (en) * 1998-03-12 2001-08-28 Kabushiki Kaisha Kobe Seiko Sho Hot rolled high strength steel sheet with excellent formability
US7090731B2 (en) * 2001-01-31 2006-08-15 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High strength steel sheet having excellent formability and method for production thereof
US20050150580A1 (en) * 2004-01-09 2005-07-14 Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) Ultra-high strength steel sheet having excellent hydrogen embrittlement resistance, and method for manufacturing the same
US20050161134A1 (en) * 2004-01-28 2005-07-28 Shinshu Tlo Co., Ltd. High strength and low yield ratio cold rolled steel sheet and method of manufacturing the same
US7591977B2 (en) * 2004-01-28 2009-09-22 Kabuhsiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High strength and low yield ratio cold rolled steel sheet and method of manufacturing the same
US7371294B2 (en) * 2004-02-02 2008-05-13 Kobe Steel, Ltd. High-strength cold-rolled steel sheet having outstanding elongation and superior stretch flange formability and method for production therof
US20050247378A1 (en) * 2004-04-22 2005-11-10 Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) High-strength cold rolled steel sheet having excellent formability, and plated steel sheet
US7413617B2 (en) * 2004-12-21 2008-08-19 Kabushiki Kaisha Kobe Seiko Sho Composite structure sheet steel with excellent elongation and stretch flange formability
US20060137768A1 (en) * 2004-12-28 2006-06-29 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High strength thin steel sheet having high hydrogen embrittlement resisting property
US20060137769A1 (en) * 2004-12-28 2006-06-29 Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) High strength thin steel sheet having high hydrogen embrittlement resisting property and high workability
US20080251160A1 (en) * 2005-03-30 2008-10-16 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd) High-Strength Cold-Rolled Steel Sheet Excellent in Uniform Elongation and Method for Manufacturing Same
US20080251161A1 (en) * 2005-03-30 2008-10-16 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High Strength Cold Rolled Steel Sheet and Plated Steel Sheet Excellent in the Balance of Strength and Workability
US20090014095A1 (en) * 2006-03-31 2009-01-15 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High-strength cold rolled steel sheet excelling in chemical treatability

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8480819B2 (en) 2010-01-29 2013-07-09 Kobe Steel, Ltd. High-strength cold-rolled steel sheet excellent in workability and method for manufacturing the same
US8932414B2 (en) 2010-03-24 2015-01-13 Kobe Steel, Ltd. High-strength steel sheet with excellent warm workability
US10544489B2 (en) 2010-11-18 2020-01-28 Kobe Steel, Ltd. Highly formable high-strength steel sheet, warm working method, and warm-worked automobile part
US9194032B2 (en) 2011-03-02 2015-11-24 Kobe Steel, Ltd. High-strength steel sheet with excellent deep drawability at room temperature and warm temperature, and method for warm working same
US20160355920A1 (en) * 2011-03-31 2016-12-08 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High-strength steel sheet excellent in workability and manufacturing method thereof
US9745639B2 (en) 2011-06-13 2017-08-29 Kobe Steel, Ltd. High-strength steel sheet excellent in workability and cold brittleness resistance, and manufacturing method thereof
GB2491958A (en) * 2011-06-13 2012-12-19 Kobe Steel Ltd Steel sheet with a tensile strength of at least 1180 MPa
US9657381B2 (en) 2011-08-17 2017-05-23 Kobe Steel, Ltd. High-strength steel sheet having excellent room-temperature formability and warm formability, and warm forming method thereof
US9890437B2 (en) 2012-02-29 2018-02-13 Kobe Steel, Ltd. High-strength steel sheet with excellent warm formability and process for manufacturing same
US9631266B2 (en) 2012-03-29 2017-04-25 Kobe Steel, Ltd. Method for manufacturing high-strength cold-rolled steel sheet with outstanding workability
US20150184274A1 (en) * 2012-07-12 2015-07-02 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High-strength hot-dip galvanized steel sheet having excellent yield strength and formability, and manufacturing method therefor
US9863028B2 (en) * 2012-07-12 2018-01-09 Kobe Steel, Ltd. High-strength hot-dip galvanized steel sheet having excellent yield strength and formability
US9322088B2 (en) 2012-12-12 2016-04-26 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High-strength steel sheet and method for producing the same
EP3009527A4 (en) * 2013-08-09 2016-07-06 Jfe Steel Corp HIGHLESS COLD-ROLLED STEEL PLATE AND METHOD FOR THE PRODUCTION THEREOF
US10077486B2 (en) 2013-08-09 2018-09-18 Jfe Steel Corporation High-strength cold-rolled steel sheet and method of manufacturing the same
US10066274B2 (en) 2013-09-27 2018-09-04 Kobe Steel, Ltd. High-strength steel sheet having excellent ductility and low-temperature toughness, and method for producing same
WO2016001895A3 (en) * 2014-07-03 2016-03-17 Arcelormittal Method for producing a high strength coated steel sheet having improved strength, ductility and formability
WO2016001898A3 (en) * 2014-07-03 2016-03-17 Arcelormittal Method for producing a high strength steel sheet having improved strength, ductility and formability
WO2016001700A1 (en) * 2014-07-03 2016-01-07 Arcelormittal Method for producing a high strength steel sheet having improved strength, ductility and formability
WO2016001702A1 (en) * 2014-07-03 2016-01-07 Arcelormittal Method for producing a high strength coated steel sheet having improved strength, ductility and formability
EP3663415A1 (en) * 2014-07-03 2020-06-10 ArcelorMittal Method for producing a high strength steel sheet having improved strength, ductility and formability
US10995383B2 (en) 2014-07-03 2021-05-04 Arcelormittal Method for producing a high strength coated steel sheet having improved strength and ductility and obtained sheet
EP3831965A1 (en) 2014-07-03 2021-06-09 ArcelorMittal Method for producing a high strength coated steel sheet having improved strength, ductility and formability
US11492676B2 (en) 2014-07-03 2022-11-08 Arcelormittal Method for producing a high strength coated steel sheet having improved strength, ductility and formability
US11555226B2 (en) 2014-07-03 2023-01-17 Arcelormittal Method for producing a high strength steel sheet having improved strength and formability and obtained sheet
US11618931B2 (en) 2014-07-03 2023-04-04 Arcelormittal Method for producing a high strength steel sheet having improved strength, ductility and formability
US12054799B2 (en) 2015-12-21 2024-08-06 Arcelormittal Method for producing a high strength steel sheet having improved ductility and formability, and obtained steel sheet
US12084738B2 (en) 2015-12-21 2024-09-10 Arcelormittal Method for producing a steel sheet having improved strength, ductility and formability

Also Published As

Publication number Publication date
CN101460646B (zh) 2012-10-10
GB2452230A (en) 2009-03-04
WO2007142197A1 (ja) 2007-12-13
JP4974341B2 (ja) 2012-07-11
GB0900057D0 (en) 2009-02-11
JP2007321237A (ja) 2007-12-13
CN101460646A (zh) 2009-06-17
GB2452230B (en) 2012-02-22
KR20090016500A (ko) 2009-02-13

Similar Documents

Publication Publication Date Title
US20100221138A1 (en) High-strength composite steel sheet having excellent moldability and delayed fracture resistance
US8197617B2 (en) High-strength steel sheet having excellent elongation, stretch flangeability and weldability
KR102400445B1 (ko) 고강도 아연 도금 강판, 고강도 부재 및 그들의 제조 방법
KR102402864B1 (ko) 고강도 아연 도금 강판 및 그의 제조 방법
US11136644B2 (en) High-strength cold rolled steel sheet and method for producing the same
US10745775B2 (en) Galvannealed steel sheet and method for producing the same
US11111553B2 (en) High-strength steel sheet and method for producing the same
US9057123B2 (en) Hot-rolled steel sheet and method for producing same
KR102635009B1 (ko) 고강도 열연 강판 및 그 제조 방법
JP5397437B2 (ja) 加工性と材質安定性に優れた冷延鋼板用熱延鋼板、溶融亜鉛めっき鋼板用熱延鋼板およびその製造方法
KR101410435B1 (ko) 성형성이 우수한 고강도 용융 아연 도금 강판 및 그 제조 방법
US12215405B2 (en) Hot-pressed member, cold-rolled steel sheet for hot pressing, and manufacturing methods therefor
WO2012067159A1 (ja) 成形性に優れた高強度鋼板、温間加工方法、および温間加工された自動車部品
US20140299238A1 (en) Hot-rolled steel sheet and method for producing same
KR100697905B1 (ko) 스폿 용접성 및 재질안정성이 우수한 고강도 용융아연도금강판 및 그 제조방법
KR102698066B1 (ko) 고강도 강판, 고강도 부재 및 그것들의 제조 방법
KR102855712B1 (ko) 강판, 부재 및 그들의 제조 방법
KR20120099517A (ko) 가공성과 스폿 용접성이 우수한 고강도 용융 아연 도금 강판 및 그 제조 방법
JP5256689B2 (ja) 加工性に優れた高強度溶融亜鉛めっき鋼板およびその製造方法
US11365459B2 (en) High strength cold rolled steel sheet and method of producing same
KR102398709B1 (ko) 고강도 강판 및 그 제조 방법
US12168810B2 (en) High-strength cold-rolled steel sheet having excellent bending workability and manufacturing method therefor
KR20120121810A (ko) 고강도 강판 및 그 제조 방법
JP4867177B2 (ja) 焼付硬化性及び成形性に優れた高張力熱延鋼板およびその製造方法
JP4848722B2 (ja) 加工性に優れた超高強度冷延鋼板の製造方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NAKAYA, MICHIHARU;MUKAI, YOICHI;SUGIMOTO, KOICHI;SIGNING DATES FROM 20090709 TO 20090724;REEL/FRAME:023053/0077

STCB Information on status: application discontinuation

Free format text: ABANDONED -- AFTER EXAMINER'S ANSWER OR BOARD OF APPEALS DECISION