EP 3447159 B1 20201111 - STEEL PLATE, PLATED STEEL PLATE, AND PRODUCTION METHOD THEREFOR
Title (en)
STEEL PLATE, PLATED STEEL PLATE, AND PRODUCTION METHOD THEREFOR
Title (de)
STAHLPLATTE, PLATTIERTE STAHLPLATTE SOWIE HERSTELLUNGSVERFAHREN DAFÜR
Title (fr)
PLAQUE D'ACIER, PLAQUE D'ACIER PLAQUÉE ET PROCÉDÉ POUR LES PRODUIRE
Publication
Application
Priority
- JP 2016084049 A 20160419
- JP 2017009300 W 20170308
Abstract (en)
[origin: EP3447159A1] A high-strength steel sheet with excellent formability and high yield ratio and hole expansion formability that has TS of 590 MPa or more and YR of 68 % or more is obtained by providing a predetermined chemical composition and a steel microstructure that contains, in area ratio, 20 % or more and 65 % or less of polygonal ferrite, 8 % or more of non-recrystallized ferrite, and 5 % or more and 25 % or less of martensite, and that contains, in volume fraction, 8 % or more of retained austenite, where an average aspect ratio of crystal grains of each phase (polygonal ferrite, martensite, and retained austenite) is 2.0 or more and 15.0 or less, wherein the polygonal ferrite has an average grain size of 6 µm or less, the martensite has an average grain size of 3 µm or less, the retained austenite has an average grain size of 3 µm or less, and a value obtained by dividing a Mn content in the retained austenite in mass% by a Mn content in the polygonal ferrite in mass% equals 2.0 or more.
IPC 8 full level
C22C 38/00 (2006.01); C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/14 (2006.01); C22C 38/60 (2006.01); C23C 2/02 (2006.01); C23C 2/06 (2006.01); C23C 2/12 (2006.01); C23C 2/28 (2006.01); C23C 2/40 (2006.01)
CPC (source: EP KR US)
C21D 8/0205 (2013.01 - US); C21D 8/0226 (2013.01 - EP KR US); C21D 8/0236 (2013.01 - EP KR US); C21D 8/0263 (2013.01 - EP US); C21D 9/46 (2013.01 - EP KR US); C22C 38/001 (2013.01 - KR US); C22C 38/002 (2013.01 - US); C22C 38/005 (2013.01 - US); C22C 38/008 (2013.01 - US); C22C 38/02 (2013.01 - EP KR US); C22C 38/04 (2013.01 - EP KR US); C22C 38/06 (2013.01 - US); C22C 38/08 (2013.01 - US); C22C 38/12 (2013.01 - US); C22C 38/14 (2013.01 - EP KR US); C22C 38/16 (2013.01 - US); C22C 38/28 (2013.01 - US); C22C 38/38 (2013.01 - US); C22C 38/60 (2013.01 - 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 2/12 (2013.01 - EP US); C23C 2/28 (2013.01 - EP KR US); C23C 2/40 (2013.01 - EP KR US); C21D 2211/001 (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)
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 3447159 A1 20190227; EP 3447159 A4 20190313; EP 3447159 B1 20201111; CN 108779536 A 20181109; CN 108779536 B 20200630; KR 102128838 B1 20200702; KR 20180132889 A 20181212; MX 2018012659 A 20190228; US 2019276907 A1 20190912; WO 2017183348 A1 20171026
DOCDB simple family (application)
EP 17785691 A 20170308; CN 201780018499 A 20170308; JP 2017009300 W 20170308; KR 20187033203 A 20170308; MX 2018012659 A 20170308; US 201716090883 A 20170308