EP 2636762 B1 20190227 - HIGH-STRENGTH COLD-ROLLED STEEL SHEET HAVING EXCELLENT DEEP-DRAWABILITY AND BAKE HARDENABILITY, AND METHOD FOR MANUFACTURING SAME
Title (en)
HIGH-STRENGTH COLD-ROLLED STEEL SHEET HAVING EXCELLENT DEEP-DRAWABILITY AND BAKE HARDENABILITY, AND METHOD FOR MANUFACTURING SAME
Title (de)
HOCHFESTES KALTGEWALZTES STAHLBLECH MIT HERVORRAGENDER TIEFZIEHBARKEIT UND BRENNHÄRTBARKEIT SOWIE HERSTELLUNGSVERFAHREN DAFÜR
Title (fr)
TÔLE D'ACIER FORTE RÉSISTANCE LAMINÉE À FROID PRÉSENTANT UNE EXCELLENTE APTITUDE À L'EMBOUTISSAGE PROFOND ET AU DURCISSEMENT APRÈS CUISSON, ET SON PROCÉDÉ DE FABRICATION
Publication
Application
Priority
- JP 2011227817 A 20111017
- JP 2010248119 A 20101105
- JP 2011074939 W 20111028
Abstract (en)
[origin: EP2636762A1] A high-strength cold rolled steel sheet having excellent deep drawability and bake hardenability, which has a tensile strength of not less than 440 MPa, an average r-value of not less than 1.20 and a bake hardening value of not less than 40 MPa, is obtained by subjecting a steel raw material having a chemical composition comprising C: 0.010-0.06 mass%, Si: more than 0.5 mass% but not more than 1.5 mass%, Mn: 1.0-3.0 mass%, Nb: 0.010-0.090 mass%, Ti: 0.015-0.15 mass% and satisfying (Nb/93)/(C/12) < 0.20 to hot rolling, cold rolling and then to annealing comprising steps of heating to a temperature of 800-900°C while a temperature region of 700-800°C is an average heating rate of less than 3°C/s, and soaking and thereafter cooling at a rate of not less than 5°C/s from the soaking temperature to a cooling stop temperature of not higher than 500°C to thereby form a microstructure comprising ferrite phase with an area ratio of not less than 70% and martensite phase with an area ratio of not less than 3%.
IPC 8 full level
C22C 38/14 (2006.01); C21D 9/48 (2006.01); C22C 38/58 (2006.01)
CPC (source: EP US)
C21D 8/005 (2013.01 - US); C21D 8/0226 (2013.01 - EP US); C21D 8/0236 (2013.01 - EP US); C21D 8/0273 (2013.01 - EP US); C22C 38/001 (2013.01 - EP US); C22C 38/008 (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 - US); C22C 38/12 (2013.01 - EP US); C22C 38/14 (2013.01 - EP US); C22C 38/18 (2013.01 - US); C22C 38/20 (2013.01 - US); C22C 38/24 (2013.01 - US); C22C 38/26 (2013.01 - US); C22C 38/28 (2013.01 - US); C22C 38/40 (2013.01 - US); C22C 38/42 (2013.01 - US); C22C 38/46 (2013.01 - US); C22C 38/48 (2013.01 - US); C22C 38/50 (2013.01 - US); C22C 38/60 (2013.01 - EP US); C21D 2211/005 (2013.01 - EP 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
DOCDB simple family (publication)
EP 2636762 A1 20130911; EP 2636762 A4 20161026; EP 2636762 B1 20190227; BR 112013011013 A2 20160823; CA 2814193 A1 20120510; CA 2814193 C 20160705; CN 103201403 A 20130710; CN 103201403 B 20160817; JP 2012112039 A 20120614; JP 5825481 B2 20151202; KR 101561358 B1 20151016; KR 20130055021 A 20130527; MX 2013005011 A 20130801; MX 350226 B 20170830; TW 201239105 A 20121001; TW I473887 B 20150221; US 2013213529 A1 20130822; WO 2012060294 A1 20120510
DOCDB simple family (application)
EP 11837944 A 20111028; BR 112013011013 A 20111028; CA 2814193 A 20111028; CN 201180053425 A 20111028; JP 2011074939 W 20111028; JP 2011227817 A 20111017; KR 20137009954 A 20111028; MX 2013005011 A 20111028; TW 100140129 A 20111103; US 201113882300 A 20111028