EP 3847284 B1 20230816 - HOT-ROLLED FLAT STEEL PRODUCT AND METHOD FOR THE PRODUCTION THEREOF
Title (en)
HOT-ROLLED FLAT STEEL PRODUCT AND METHOD FOR THE PRODUCTION THEREOF
Title (de)
WARMGEWALZTES STAHLFLACHPRODUKT UND VERFAHREN ZU SEINER HERSTELLUNG
Title (fr)
PRODUIT PLAT LAMINÉ À CHAUD EN ACIER ET PROCÉDÉ DE FABRICATION
Publication
Application
Priority
EP 2018074005 W 20180906
Abstract (en)
[origin: WO2020048599A1] The invention relates to a hot-rolled flat steel product having a tensile strength Rm of ≤ 550 MPa, a hole expansion ratio λ of ≤ 30%, and a microstructure consisting of ≤ 90 area % ferrite and, as the remainder, ≤ 10 area % perlite or cementite, with embedded carbonitride precipitates having an average diameter of ≤ 10 nm. The flat steel product consists of a steel containing (in wt%) 0.02-0.3% C, ≤ 0.7% Si, ≤ 1.0% AI, 0.2-2.5% Mn, 0.05-0.5% Cr, ≤ 0.02% P, ≤ 0.005% S, ≤ 0.01% N, ≤ 0.1% Cu and at least one element forming carbonitride precipitates from the group "Ti, Nb, V" and, as the remainder, Fe and unavoidable impurities, with the following provisos:- If V is present, the sum of the TiGEW and NbGEW contents is - 0.01 wt%; - if Ti or Nb are present, VGEW is ≤ 0.01 wt%; - for XGEW [wt%]=TiGEW+(VGEW/1.06)+(NbGEW/1.94), the following applies: 0.02% ≤ XGEW ≤ 0.5%; - for ratio = (XAT+CrAT) / (CAT+NAT), the following applies: 0.5 ≤ ratio ≤ 2.0, where XAT = TiAT+VAT+NbAT; wherein ΤiΑT, VAT, NbAT, CrAT, CAT and NAT correspond to the Ti content TiGEW, the V content VGEW, the Nb content NbGEW, the Cr content CrGEW, the C content CGEW and ΝΑT the N content NGEW respectively, each converted into atomic %, and the TiGEW, VGEW, NbGEW, CrGEW, CGEW and NGEW contents are given in wt%.The invention also relates to a method for producing such a flat steel product.
IPC 8 full level
C21D 8/02 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/24 (2006.01); C22C 38/26 (2006.01); C22C 38/28 (2006.01)
CPC (source: EP)
C21D 8/0226 (2013.01); C22C 38/001 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/24 (2013.01); C22C 38/26 (2013.01); C22C 38/28 (2013.01); C21D 2211/004 (2013.01); C21D 2211/005 (2013.01); C21D 2211/009 (2013.01)
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)
WO 2020048599 A1 20200312; EP 3847284 A1 20210714; EP 3847284 B1 20230816; EP 3847284 C0 20230816
DOCDB simple family (application)
EP 2018074005 W 20180906; EP 18773945 A 20180906