EP 2246456 B1 20150812 - HIGH-STRENGTH STEEL SHEET AND PROCESS FOR PRODUCTION THEREOF
Title (en)
HIGH-STRENGTH STEEL SHEET AND PROCESS FOR PRODUCTION THEREOF
Title (de)
HOCHFESTES STAHLBLECH UND HERSTELLUNGSVERFAHREN DAFÜR
Title (fr)
TÔLE D'ACIER HAUTE RÉSISTANCE ET SON PROCÉDÉ DE PRODUCTION
Publication
Application
Priority
- JP 2009051915 W 20090129
- JP 2008021403 A 20080131
Abstract (en)
[origin: EP2246456A1] There is provided a high strength steel sheet having a tensile strength of 900 MPa or higher that can achieve both high strength and good formability. The high strength steel sheet has a composition including, on a mass basis, C: 0.1% or more and 0.3% or less; Si: 2.0% or less; Mn: 0.5% or more and 3.0% or less; P: 0.1% or less; S: 0.07% or less; Al: 1.0% or less; and N: 0.008% or less, with the balance Fe and incidental impurities. In the high strength steel sheet, a steel microstructure includes, on an area ratio basis, 5% or more and 80% or less of ferrite, 15% or more of autotempered martensite, 10% or less of bainite, 5% or less of retained austenite, and 40% or less of as-quenched martensite; the mean hardness of the autotempered martensite is HV ‰¤ 700; and the mean number of precipitated iron-based carbide grains each having a size of 5 nm or more and 0.5 µm or less and included in the autotempered martensite is 5 × 10 4 or more per 1 mm 2 .
IPC 8 full level
C22C 38/60 (2006.01); C21D 9/46 (2006.01); C23C 2/06 (2006.01); C23C 2/28 (2006.01)
CPC (source: EP KR US)
C21D 1/25 (2013.01 - EP US); C21D 6/005 (2013.01 - EP US); C21D 8/0426 (2013.01 - EP US); C21D 8/0436 (2013.01 - EP US); C21D 8/0447 (2013.01 - EP US); C21D 9/46 (2013.01 - KR); C22C 38/001 (2013.01 - KR); C22C 38/02 (2013.01 - KR); C22C 38/04 (2013.01 - EP KR US); C22C 38/06 (2013.01 - KR); C22C 38/60 (2013.01 - KR); C23C 2/02 (2013.01 - EP US); C23C 2/0224 (2022.08 - EP KR US); C23C 2/024 (2022.08 - EP KR US); C23C 2/06 (2013.01 - EP KR US); C23C 2/28 (2013.01 - EP US); C23C 2/29 (2022.08 - KR); C21D 8/0468 (2013.01 - EP US); C21D 2211/002 (2013.01 - EP KR US); C21D 2211/004 (2013.01 - EP KR US); C21D 2211/005 (2013.01 - EP KR US); C21D 2211/008 (2013.01 - EP KR US)
Designated contracting state (EPC)
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 SE SI SK TR
DOCDB simple family (publication)
EP 2246456 A1 20101103; EP 2246456 A4 20140423; EP 2246456 B1 20150812; EP 2246456 B9 20161221; CA 2713181 A1 20090806; CA 2713181 C 20131210; CN 101932746 A 20101229; CN 101932746 B 20120509; JP 2009203550 A 20090910; JP 5365217 B2 20131211; KR 101225321 B1 20130122; KR 20100101697 A 20100917; MX 2010008227 A 20100830; US 2011030854 A1 20110210; WO 2009096596 A1 20090806
DOCDB simple family (application)
EP 09706046 A 20090129; CA 2713181 A 20090129; CN 200980103828 A 20090129; JP 2009015840 A 20090127; JP 2009051915 W 20090129; KR 20107017843 A 20090129; MX 2010008227 A 20090129; US 86552709 A 20090129