EP 1954842 A1 20080813 - METHOD FOR PRODUCING HOT STRIP WITH A MULTIPHASE STRUCTURE
Title (en)
METHOD FOR PRODUCING HOT STRIP WITH A MULTIPHASE STRUCTURE
Title (de)
VERFAHREN ZUR HERSTELLUNG VON WARMBAND MIT MEHRPHASENGEFÜGE
Title (fr)
PROCEDE DE FABRICATION D'UNE TOLE CHAUDE PRESENTANT UNE STRUCTURE MULTIPHASE
Publication
Application
Priority
- EP 2006009755 W 20061010
- DE 102005051052 A 20051025
Abstract (en)
[origin: WO2007048497A1] For the production of hot strip referred to as TRIP steel (transformation induced plasticity), with a multiphase structure and with outstandingly good deformation properties along with high strengths, from the hot-rolled state, the invention proposes a method which is carried out with a predetermined chemical composition of the steel grade used within the limits 0.12 - 0.25% C; 0.05 - 1.8% Si; 1.0 -2.0% Mn; the remainder Fe and customary accompanying elements and with a combined rolling and cooling strategy in such a way that a structure comprising 40 - 70% ferrite, 15 - 45% bainite and 5 - 20% residual austenite is obtained, wherein the finish rolling of the hot strip (7) is performed to set a very fine austenite grain (d < 8 µm) in the final forming operation (6') at temperatures between 770 and 830°C just above Ar3 in the region of the metastable austenite, and a controlled two-stage cooling (10, 11, 12) is carried out after the last rolling stand (6') of the hot strip (7) to a strip temperature in the range of bainite formation of 320 - 480°C, with a holding time of about 650 - 730°C, the beginning of which is determined by the entry of the cooling curve into the ferrite region and the duration of which is determined by the transformation of the austenite into at least 40% ferrite.
IPC 8 full level
C21D 8/04 (2006.01); C21D 1/20 (2006.01); C21D 8/02 (2006.01)
CPC (source: EP KR US)
C21D 1/20 (2013.01 - EP KR US); C21D 8/02 (2013.01 - KR); C21D 8/0215 (2013.01 - EP US); C21D 8/0226 (2013.01 - EP US); C21D 8/0263 (2013.01 - EP US); C21D 8/04 (2013.01 - KR); C21D 8/0415 (2013.01 - EP US); C21D 8/0426 (2013.01 - EP US); C21D 8/0463 (2013.01 - EP US); C21D 2211/001 (2013.01 - EP US); C21D 2211/002 (2013.01 - EP US); C21D 2211/005 (2013.01 - EP US)
Citation (search report)
See references of WO 2007048497A1
Designated contracting state (EPC)
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR
DOCDB simple family (publication)
DE 102005051052 A1 20070426; AU 2006308245 A1 20070503; AU 2006308245 A2 20080619; AU 2006308245 B2 20100930; BR PI0617753 A2 20110802; CA 2625564 A1 20070503; CN 101297049 A 20081029; CN 101297049 B 20120111; EP 1954842 A1 20080813; JP 2009512783 A 20090326; JP 5130221 B2 20130130; KR 20080063307 A 20080703; RU 2008120667 A 20091210; RU 2398028 C2 20100827; TW 200724690 A 20070701; UA 90436 C2 20100426; US 2009214377 A1 20090827; WO 2007048497 A1 20070503; ZA 200802524 B 20090624
DOCDB simple family (application)
DE 102005051052 A 20051025; AU 2006308245 A 20061010; BR PI0617753 A 20061010; CA 2625564 A 20061010; CN 200680039706 A 20061010; EP 06806132 A 20061010; EP 2006009755 W 20061010; JP 2008536963 A 20061010; KR 20087008724 A 20080411; RU 2008120667 A 20061010; TW 95137306 A 20061011; UA A200807183 A 20061010; US 8382206 A 20061010; ZA 200802524 A 20080318