EP 2028282 B1 20120613 - Dual-phase steel, flat product made of such dual-phase steel and method for manufacturing a flat product
Title (en)
Dual-phase steel, flat product made of such dual-phase steel and method for manufacturing a flat product
Title (de)
Dualphasenstahl, Flachprodukt aus einem solchen Dualphasenstahl und Verfahren zur Herstellung eines Flachprodukts
Title (fr)
Acier en phase double, produit plat à partir d'un tel acier en phase double et son procédé de fabrication
Publication
Application
Priority
EP 07114398 A 20070815
Abstract (en)
[origin: EP2028282A1] Dual-phase steel comprises 20-70% of martensite, up to 8% of residual austenite and balance of ferrite and/or bainite and which possess a tensile strength of at least 950 MPa, and composition of carbon (0.1-0.2 wt.%), silicon (0.1-0.6 wt.%), manganese (1.5-2.5 wt.%), chromium (0.2-0.8 wt.%), titanium (0.02-0.08 wt.%), boron (less than 0.002 wt.%), molybdenum (less than 0.25 wt.%), aluminum (less than 0.1 wt.%), phosphorus (= 0.2 wt.%), sulfur (= 0.01 wt.%), nitrogen (= 0.012 wt.%) and balance of iron and unavoidable contamination. Independent claims are included for: (1) a flat product comprising the dual-phase steel; (2) production of a hot laminated strip with a tensile strength of at least 950 MPa and a dual phase structure, comprising melting the dual-phase steel, pouring the melt to a preproduct such as slab or thin slab, reheating or holding the preproduct at a hot rolling starting temperature of 1100-1300[deg] C, hot rolling the preproduct at a hot rolling temperature of 800-950[deg] C to the hot laminated strip and winding the hot laminated strip at a winder temperature of up to 570[deg] C; and (3) production of a cold strip with a tensile strength of at least 950 MPa and a dual phase structure, comprising melting the composite dual-phase steel, pouring the melt to a preproduct such as slab or thin slab, reheating or holding the preproduct at a hot rolling starting temperature of 1100-1300[deg] C, hot rolling the preproduct at a hot rolling temperature of 800-950[deg] C to the hot laminated strip, winding the hot laminated strip at a winder temperature of 500-650[deg] C, carrying out cold rolling of the hot laminated strip after the winding step, tempering the cold strip to a tempering temperature of 700-900[deg] C and controlled cooling of the tempered cold strip.
IPC 8 full level
C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/28 (2006.01); C22C 38/38 (2006.01)
CPC (source: EP US)
C21D 8/02 (2013.01 - EP US); C22C 38/02 (2013.01 - EP US); C22C 38/28 (2013.01 - EP US); C22C 38/38 (2013.01 - EP US); Y10T 428/12799 (2015.01 - EP US); Y10T 428/12972 (2015.01 - EP US)
Citation (examination)
EP 0966547 B1 20011004 - THYSSENKRUPP STAHL AG [DE]
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 MT NL PL PT RO SE SI SK TR
DOCDB simple family (publication)
EP 2028282 A1 20090225; EP 2028282 B1 20120613; CN 101802233 A 20100811; CN 101802233 B 20130814; ES 2387040 T3 20120912; JP 2010535946 A 20101125; JP 5486496 B2 20140507; PL 2028282 T3 20121130; US 2010273024 A1 20101028; WO 2009021897 A1 20090219
DOCDB simple family (application)
EP 07114398 A 20070815; CN 200880103426 A 20080807; EP 2008060381 W 20080807; ES 07114398 T 20070815; JP 2010520536 A 20080807; PL 07114398 T 20070815; US 67338808 A 20080807