EP 3279363 B1 20200513 - 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 (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 À HAUTE RÉSISTANCE PRÉSENTANT D'EXCELLENTES CARACTÉRISTIQUES D'APTITUDE AU FAÇONNAGE ET DE COLLISION ET PRÉSENTANT UNE RÉSISTANCE À LA TRACTION SUPÉRIEURE OU ÉGALE À 980 MPa, ET SON PROCÉDÉ DE PRODUCTION
Publication
Application
Priority
- JP 2015071438 A 20150331
- JP 2015225507 A 20151118
- JP 2016056169 W 20160301
Abstract (en)
[origin: EP3279363A1] 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 more than 10% to 65% 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 38/16 (2006.01); C22C 38/38 (2006.01); C23C 2/28 (2006.01); C23C 2/40 (2006.01); C25D 3/22 (2006.01)
CPC (source: EP US)
C21D 6/001 (2013.01 - EP US); C21D 6/002 (2013.01 - EP US); C21D 6/005 (2013.01 - EP US); C21D 6/008 (2013.01 - EP US); C21D 8/02 (2013.01 - EP US); C21D 8/0205 (2013.01 - EP US); C21D 8/0226 (2013.01 - EP US); C21D 8/0247 (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 38/06 (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 38/16 (2013.01 - EP US); C22C 38/38 (2013.01 - EP US); C22C 38/60 (2013.01 - US); C23C 2/28 (2013.01 - EP US); C23C 2/29 (2022.08 - EP US); C23C 2/40 (2013.01 - US); C25D 3/22 (2013.01 - US); C21D 2211/001 (2013.01 - EP US); C21D 2211/005 (2013.01 - EP US); C21D 2211/008 (2013.01 - EP US); C22C 38/60 (2013.01 - EP)
Citation (opposition)
Opponent : ARCELORMITTAL
- EP 3128023 A1 20170208 - JFE STEEL CORP [JP]
- US 2012312433 A1 20121213 - MIZUTA SAE [JP], et al
- W.C.LESLIE, THE PHYSICAL METALLURGY OF STEELS, pages 231
Opponent : Kabushiki Kaisha Kobe Seiko Sho
- EP 3128023 A1 20170208 - JFE STEEL CORP [JP]
- US 20120312433 A
- W.C.LESLIE, THE PHYSICAL METALLURGY OF STEELS, pages 231
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 3279363 A1 20180207; EP 3279363 A4 20180815; EP 3279363 B1 20200513; CN 107429371 A 20171201; CN 107429371 B 20200421; JP 2016194139 A 20161117; JP 6554397 B2 20190731; KR 101970095 B1 20190417; KR 20170130578 A 20171128; MX 2017012438 A 20180126; US 2018044752 A1 20180215
DOCDB simple family (application)
EP 16772044 A 20160301; CN 201680017729 A 20160301; JP 2015225507 A 20151118; KR 20177030773 A 20160301; MX 2017012438 A 20160301; US 201615554875 A 20160301