EP 3263728 A1 20180103 - HIGH-STRENGTH COLD-ROLLED STEEL PLATE AND METHOD FOR PRODUCING SAME
Title (en)
HIGH-STRENGTH COLD-ROLLED STEEL PLATE AND METHOD FOR PRODUCING SAME
Title (de)
HOCHFESTE KALTGEWALZTE STAHLPLATTE UND VERFAHREN ZU DEREN HERSTELLUNG
Title (fr)
TÔLE EN ACIER LAMINÉE À FROID HAUTEMENT RÉSISTANTE, ET PROCÉDÉ DE FABRICATION DE CELLE-CI
Publication
Application
Priority
- JP 2015038506 A 20150227
- JP 2015006347 W 20151221
Abstract (en)
Provided are a high-strength cold-rolled steel sheet excellent in terms of elongation (EL) and hole expansion ratio (») having a low yield ratio (YR) and a method for manufacturing the steel sheet. The steel sheet has a chemical composition containing, by mass%, C: 0.15% to 0.25%, Si: 1.0% to 2.0%, Mn: 1.8% to 2.5%, P: 0.10% or less, S: 0.010% or less, Al: 0.10% or less, N: 0.010% or less, and the balance being Fe and inevitable impurities, and a multi-phase microstructure including ferrite having an average crystal grain diameter of 5 µm or less in an amount of 30% to 55% in terms of volume fraction, retained austenite having an average crystal grain diameter of 2 µm or less in an amount of 5% to 15% in terms of volume fraction, and tempered martensite having an average crystal grain diameter of 2 µm or less in an amount of 30% to 60% in terms of volume fraction, in which the number of grains of the retained austenite existing in an area of 1000 µm 2 is 10 or more.
IPC 8 full level
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 38/18 (2006.01)
CPC (source: EP KR US)
C21D 6/005 (2013.01 - EP US); C21D 6/008 (2013.01 - EP US); C21D 8/0236 (2013.01 - EP US); C21D 8/0247 (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 - EP US); C22C 38/002 (2013.01 - EP US); C22C 38/005 (2013.01 - EP US); C22C 38/02 (2013.01 - EP KR US); C22C 38/04 (2013.01 - EP KR 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 38/18 (2013.01 - EP US); C21D 2211/001 (2013.01 - EP KR US); C21D 2211/004 (2013.01 - KR); C21D 2211/005 (2013.01 - EP KR US); C21D 2211/008 (2013.01 - EP 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
Designated extension state (EPC)
BA ME
DOCDB simple family (publication)
EP 3263728 A1 20180103; EP 3263728 A4 20180103; EP 3263728 B1 20190911; CN 107406930 A 20171128; CN 107406930 B 20190723; JP 6048620 B1 20161221; JP WO2016135794 A1 20170427; KR 102016432 B1 20190830; KR 20170107057 A 20170922; MX 2017010910 A 20171124; US 2018127856 A1 20180510; WO 2016135794 A1 20160901
DOCDB simple family (application)
EP 15883094 A 20151221; CN 201580076970 A 20151221; JP 2015006347 W 20151221; JP 2016522827 A 20151221; KR 20177023461 A 20151221; MX 2017010910 A 20151221; US 201515553408 A 20151221