Title (en)

HIGH-STRENGTH COLD-ROLLED STEEL SHEET HAVING EXCELLENT WORKABILITY AND COLLISION CHARACTERISTICS AND HAVING TENSILE STRENGTH OF 980 MPa OR MORE, AND METHOD FOR PRODUCING SAME

Title (de)

HOCHFESTES KALTGEWALZTES STAHLBLECH MIT HERVORRAGENDEN BEARBEITBARKEITS- UND KOLLISIONSEIGENSCHAFTEN UND EINER ZUGFESTIGKEIT VON 980 MPA ODER MEHR SOWIE VERFAHREN ZUR HERSTELLUNG DAVON

Title (fr)

TÔLE D'ACIER LAMINÉE À FROID HAUTE RÉSISTANCE, AYANT UNE EXCELLENTE APTITUDE AU FAÇONNAGE, DE TRÈS BONNES CARACTÉRISTIQUES DE COLLISION ET UNE RÉSISTANCE À LA TRACTION DE 980 MPa OU PLUS, ET PROCÉDÉ DE PRODUCTION

Publication

EP 3279362 B1 20210421 (EN)

Application

EP 16772043 A 20160301

Priority

• JP 2015071437 A 20150331
• JP 2015225506 A 20151118
• JP 2016056168 W 20160301

Abstract (en)

[origin: EP3279362A1] Provided are: a high-strength cold-rolled steel sheet having a tensile strength of 980 MPa or more, having good formability as evaluated by ductility and stretch-flangeability, and having excellent crashworthiness; and a method for producing the steel sheet. In this high-strength cold-rolled steel sheet, the metal structure at a position of 1/4 of the sheet thickness satisfies (1) to (4) below. (1) The area ratio of ferrite is 0% or more and 10% or less, with the balance being a hard phase including quenched martensite and retained austenite and including at least one selected from the group consisting of bainitic ferrite, bainite, and tempered martensite. (2) The volume ratio V ³ of retained austenite is 5% or more to 30% or less. (3) The area ratio V MA of an MA structure in which quenched martensite and retained austenite are combined is 3% or more to 25% or less, and the average circle-equivalent diameter of the MA structure is 2.0 µm or less. (4) The ratio V MA /V ³ of the area ratio V MA of the MA structure to the volume ratio V ³ of the retained austenite is 0.50 to 1.50.

IPC 8 full level

C22C 38/60 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/08 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/20 (2006.01); C22C 38/34 (2006.01); C22C 38/38 (2006.01); C23C 2/02 (2006.01); C23C 2/06 (2006.01); C23C 2/26 (2006.01); C23C 2/28 (2006.01); C23C 2/40 (2006.01)

CPC (source: EP US)

C21D 6/005 (2013.01 - EP US); C21D 6/008 (2013.01 - EP US); C21D 8/0205 (2013.01 - EP US); C21D 8/0226 (2013.01 - EP US); C21D 8/0236 (2013.01 - EP US); C21D 8/0273 (2013.01 - EP US); C21D 9/46 (2013.01 - EP US); C22C 38/001 (2013.01 - EP US); C22C 38/002 (2013.01 - EP US); C22C 38/005 (2013.01 - EP US); C22C 38/02 (2013.01 - EP US); C22C 38/04 (2013.01 - EP US); C22C 38/06 (2013.01 - EP US); C22C 38/08 (2013.01 - EP US); C22C 38/12 (2013.01 - EP US); C22C 38/14 (2013.01 - EP US); C22C 38/20 (2013.01 - EP US); C22C 38/34 (2013.01 - EP US); C22C 38/38 (2013.01 - EP US); C23C 2/02 (2013.01 - EP US); C23C 2/0224 (2022.08 - EP US); C23C 2/024 (2022.08 - EP US); C23C 2/06 (2013.01 - EP US); C23C 2/28 (2013.01 - EP US); C23C 2/40 (2013.01 - EP US); C21D 2211/001 (2013.01 - EP US); C21D 2211/005 (2013.01 - EP US); C21D 2211/008 (2013.01 - EP US)

Citation (opposition)

Opponent : ArcelorMittal

• EP 3128023 A1 20170208 - JFE STEEL CORP [JP]
• US 2012312433 A1 20121213 - MIZUTA SAE [JP], et al

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DOCDB simple family (publication)

EP 3279362 A1 20180207; EP 3279362 A4 20180822; EP 3279362 B1 20210421; CN 107429370 A 20171201; CN 107429370 B 20200124; JP 2016194138 A 20161117; JP 6554396 B2 20190731; KR 102174558 B1 20201105; KR 20170131606 A 20171129; MX 2017012442 A 20180126; US 2018037964 A1 20180208

DOCDB simple family (application)

EP 16772043 A 20160301; CN 201680017718 A 20160301; JP 2015225506 A 20151118; KR 20177030765 A 20160301; MX 2017012442 A 20160301; US 201615554843 A 20160301