EP 3807429 A1 20210421 - FLAT STEEL PRODUCT AND METHOD FOR THE PRODUCTION THEREOF
Title (en)
FLAT STEEL PRODUCT AND METHOD FOR THE PRODUCTION THEREOF
Title (de)
STAHLFLACHPRODUKT UND VERFAHREN ZU SEINER HERSTELLUNG
Title (fr)
PRODUIT PLAT EN ACIER ET PROCÉDÉ DE FABRICATION
Publication
Application
Priority
- EP 2018065512 W 20180612
- EP 2019065323 W 20190612
Abstract (en)
[origin: WO2019238741A1] The present invention relates to a flat steel product which has good deep-drawing ability, low edge-crack sensitivity and good bending behaviour. To this end, the flat steel product contains a steel which consists of (in wt%) 0.1-0.5% C, 1.0-3.0% Mn, 0.9-1.5% Si, up to 1.5% AI, up to 0.008% N, up to 0.020% P, up to 0.005% S, 0.01-1% Cr and optionally one or more of the following elements: up to 0.2% Mo, up to 0.01% B, up to 0.5% Cu, up to 0.5% Ni and optionally a total of 0.005-0.2% microalloying elements, the remainder being iron and unavoidable impurities, wherein 75 < (Mn2 + 55*Cr)/Cr < 3000 where Mn is the Mn content of the steel in wt% and Cr is the Cr content of the steel in wt%. The steel has a structure which consists of at least 80 area % martensite, of which at least 75 area % is tempered martensite and at most 25 area % is non-tempered martensite, at least 5 volume % residual austenite, 0.5 to 10 area % ferrite and at most 5 area % bainite, wherein in the region of the phase boundary between tempered martensite and residual austenite there is a low-Mn ferrite seam which has a width of at least 4 nm and at most 12 nm and the Mn content of which is at most 50% of the average Mn content of the flat steel product. The flat steel product contains carbides with a length of less than or equal to 250 nm.The invention also relates to a method for producing a flat steel product according to the invention, in which method the structural characteristics of the flat steel product according to the invention are set by suitable heat treatment.
IPC 8 full level
C21D 8/04 (2006.01); C21D 9/48 (2006.01); C22C 38/24 (2006.01); C22C 38/26 (2006.01); C22C 38/28 (2006.01); C22C 38/38 (2006.01)
CPC (source: EP KR US)
C21D 8/0405 (2013.01 - US); C21D 8/0426 (2013.01 - US); C21D 8/0436 (2013.01 - EP US); C21D 8/0447 (2013.01 - EP KR); C21D 9/48 (2013.01 - EP KR); C22C 38/001 (2013.01 - US); C22C 38/002 (2013.01 - US); C22C 38/02 (2013.01 - US); C22C 38/04 (2013.01 - US); C22C 38/06 (2013.01 - US); C22C 38/20 (2013.01 - KR US); C22C 38/22 (2013.01 - KR US); C22C 38/24 (2013.01 - EP KR); C22C 38/26 (2013.01 - EP); C22C 38/28 (2013.01 - EP); C22C 38/32 (2013.01 - KR US); C22C 38/38 (2013.01 - EP KR); C22C 38/40 (2013.01 - US); C23G 1/00 (2013.01 - US); C21D 2211/001 (2013.01 - EP KR US); C21D 2211/002 (2013.01 - US); C21D 2211/004 (2013.01 - EP KR); C21D 2211/005 (2013.01 - EP KR US); C21D 2211/008 (2013.01 - EP KR US); C23C 2/06 (2013.01 - US)
Citation (search report)
See references of WO 2019238741A1
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)
WO 2019238741 A1 20191219; CN 112313349 A 20210202; CN 112313349 B 20230414; EP 3807429 A1 20210421; JP 2021527167 A 20211011; JP 7492460 B2 20240529; KR 20210019440 A 20210222; MX 2020012411 A 20210209; US 11597986 B2 20230307; US 2021262069 A1 20210826
DOCDB simple family (application)
EP 2019065323 W 20190612; CN 201980040022 A 20190612; EP 19731909 A 20190612; JP 2020568682 A 20190612; KR 20207035542 A 20190612; MX 2020012411 A 20190612; US 201917251302 A 20190612