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.