公开(公告)号：US20250011892A1

公开(公告)日：2025-01-09

申请号：US18706476

申请日：2022-11-02

Applicant: ArcelorMittal

Inventor： Deborah HERRY ,  Fabrice GERMAIN ,  Clément PHILIPPOT ,  Sandra LE GUILLARD

IPC: C21D9/46 ,  B21D22/02 ,  C21D1/18 ,  C21D6/00 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C22C38/44 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58

Abstract: Steel sheet suitable for a multistep hot stamping process and associated manufacturing process, the steel sheet having a composition including, by weight percent: C: 0.13-0.4%, Mn: 0.4-4.2%, Si: 0.1-2.5%, Cr≤2%, Mo≤0.65%, Nb≤0.1%, Al≤3.0%, Ti≤0.1%, B≤0.005%, P≤0.025%, S≤0.01%, N≤0.01%, Ni≤2.0%, Ca≤0.1%, W≤0.30%, V≤0.1%, Cu≤0.2%, wherein Q is less than 20, the factor Q being defined as (the elements are expressed in weight percent): Q=114−68*C−18*Mn+20*Si−56*Cr−61*Ni−37*Al+39*Mo+79*Nb−17691*B, the steel sheet having a microstructure including, in surface fraction, from 60% to 100% of recrystallized ferrite, less than 40% of the sum of martensite, bainite and carbides and less than 5% of non-recrystallized ferrite.

公开(公告)号：US20240002993A1

公开(公告)日：2024-01-04

申请号：US18038104

申请日：2021-12-03

Applicant: ArcelorMittal

Inventor： Clément PHILIPPOT ,  Alice DUMONT ,  Deborah HERRY ,  Martin BEAUVAIS

IPC: C23C2/12 ,  C22C38/38 ,  C22C38/28 ,  C22C38/00 ,  C22C38/32 ,  C22C38/02 ,  C22C38/06 ,  C21D8/02 ,  C21D1/02 ,  C23C2/40 ,  B21C47/02 ,  C21D1/673 ,  C23C2/02 ,  C23G1/08

CPC classification number: C23C2/12 ,  C22C38/38 ,  C22C38/28 ,  C22C38/001 ,  C22C38/002 ,  C22C38/32 ,  C22C38/02 ,  C22C38/06 ,  C21D8/0257 ,  C21D8/0226 ,  C21D8/0263 ,  C21D8/0273 ,  C21D1/02 ,  C23C2/40 ,  B21C47/02 ,  C21D1/673 ,  C21D8/0278 ,  C23C2/024 ,  C23G1/08 ,  C21D2211/008 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/001

Abstract: A coated steel sheet and press hardened steel part having a composition including, by weight percent: C 0.15-0.25%, Mn 0.5-1.8%, Si 0.1-1.25%, Al 0.01-0.1%, Cr 0.1-1.0%, Ti 0.01-0.1%, B 0.001-0.004%, P≤0.020%, S≤0.010%, N≤0.010% the remainder of the composition being iron and unavoidable impurities resulting from the smelting. The press hardened steel part includes a bulk having a microstructure including, in surface fraction, more than 95% of martensite and less than 5% of bainite, a coating layer at the surface of the steel part, a ferritic interdiffusion layer between the coating layer and the bulk, and a ratio between the ferritic grain width in the interdiffusion layer GWint over prior austenite grain size in the bulk PAGSbulk, satisfying following equation (GWint/PAGSbulk)−1≥30%.