EP 2907887 B1 20181205 - COLD-ROLLED STEEL SHEET WITH SUPERIOR SHAPE FIXABILITY AND MANUFACTURING METHOD THEREFOR
Title (en)
COLD-ROLLED STEEL SHEET WITH SUPERIOR SHAPE FIXABILITY AND MANUFACTURING METHOD THEREFOR
Title (de)
KALTGEWALZTES STAHLBLECH MIT ÜBERLEGENER FORMFESTIGKEIT UND HERSTELLUNGSVERFAHREN DAFÜR
Title (fr)
TÔLE D'ACIER LAMINÉE À FROID À CAPACITÉ DE FIXATION DE FORME SUPÉRIEURE ET SON PROCÉDÉ DE FABRICATION
Publication
Application
Priority
JP 2012006532 W 20121011
Abstract (en)
[origin: EP2907887A1] Provided is a cold-rolled steel sheet with excellent shape fixability and a method for manufacturing the same. A steel material having a chemical composition containing 0.0010% to 0.0030% C, 0.05% or less Si, 0.1% to 0.5% Mn, 0.021% to 0.060% Ti, and 0.0005% to 0.0050% B on a mass basis such that B/C satisfies 0.5 or more is subjected to a hot rolling step in which the steel material is finish-rolled at a finishing delivery temperature of 870°C to 950°C and is coiled at a coiling temperature of 450°C to 630°C; a cold-rolling step in which cold rolling is performed at a rolling reduction of 90% or less; and an annealing step in which heating is performed up to a holding temperature in the range of 700°C to 850°C at an average heating rate of 1 °C/s to 30 °C/s in a temperature region not lower than 600°C after the cold rolling step, retention is performed for 30 s to 200 s, and cooling is then performed at a cooling rate of 3 °C/s or more in a temperature region down to 600°C, whereby a cold-rolled steel sheet having a microstructure dominated by ferrite with an average grain size of 10 µm to 30 µm, a proportional limit of 100 MPa or less, and excellent shape fixability is obtained.
IPC 8 full level
C21D 1/26 (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 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/18 (2006.01); C22C 38/26 (2006.01); C22C 38/28 (2006.01); C22C 38/32 (2006.01)
CPC (source: EP US)
C21D 1/26 (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 8/0226 (2013.01 - EP US); C21D 8/0236 (2013.01 - EP US); C21D 8/0263 (2013.01 - EP US); C21D 8/0273 (2013.01 - EP US); C21D 9/46 (2013.01 - US); C22C 38/001 (2013.01 - EP US); C22C 38/002 (2013.01 - EP US); C22C 38/004 (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 38/12 (2013.01 - EP US); C22C 38/14 (2013.01 - EP US); C22C 38/18 (2013.01 - EP US); C22C 38/26 (2013.01 - US); C22C 38/28 (2013.01 - US); C22C 38/32 (2013.01 - EP US); C21D 2211/005 (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 2907887 A1 20150819; EP 2907887 A4 20151202; EP 2907887 B1 20181205; CN 104870678 A 20150826; IN 599KON2015 A 20150717; JP WO2014057519 A1 20160825; KR 20150060957 A 20150603; US 2015252456 A1 20150910; WO 2014057519 A1 20140417
DOCDB simple family (application)
EP 12886281 A 20121011; CN 201280076329 A 20121011; IN 599KON2015 A 20150309; JP 2012006532 W 20121011; JP 2014540643 A 20121011; KR 20157011022 A 20121011; US 201214433869 A 20121011