公开(公告)号：US20160312326A1

公开(公告)日：2016-10-27

申请号：US15102386

申请日：2014-12-05

Applicant: ARCELORMITTAL

Inventor： Josée DRILLET ,  Véronique HEBERT

IPC: C21D9/46 ,  C22C38/28 ,  C22C38/26 ,  C22C38/22 ,  C22C38/32 ,  C23C2/36 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C23C2/02 ,  C23C2/06 ,  C22C38/38 ,  C22C38/06

Abstract: A cold-rolled and annealed steel sheet is provided, the chemical composition of which comprises, the contents being expressed by weight percent: 0.10≦C≦0.13% 2.4≦Mn≦2.8% 0.30≦Si≦0.55% 0.30≦Cr≦0.56% 0.020≦Ti≦0.050% 0.0020≦B≦0.0040% 0.005≦Al≦0.050% Mo≦0.010% Nb≦0.040% 0.002≦N≦0.008% S≦0.005% P≦0.020%, the remainder consisting of iron and unavoidable impurities resulting from the smelting, the steel sheet having a microstructure consisting of, in surface proportion, martensite and/or lower bainite, said martensite comprising fresh martensite and/or self-tempered martensite, the sum of the surface proportions of martensite and lower bainite being comprised between 60 to 95%, 4 to 35% of low carbide containing bainite, 0 to 5% of ferrite, and less than 5% of retained austenite in island form.

公开(公告)号：US20230141248A1

公开(公告)日：2023-05-11

申请号：US17907836

申请日：2021-02-08

Applicant: ArcelorMittal

Inventor： Gregory INACIO DA ROSA ,  Lijia ZHAO ,  Dongwei FAN ,  Josée DRILLET

IPC: C21D9/46 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/22 ,  C22C38/06 ,  C22C38/02 ,  C21D8/02

CPC classification number: C21D9/46 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/22 ,  C22C38/06 ,  C22C38/02 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0205 ,  C21D8/0273 ,  C21D8/0278 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008

Abstract: A cold rolled and galvannealed steel sheet having a composition including, by weight percent: C 0.15-0.25%, Mn 2.4-3.5%, Si 0.30-0.90%, Cr 0.30-0.70%, Mo 0.05-0.35%, Al 0.001-0.09%, Ti 0.01-0.06, B 0.0010-0.0040%, Nb 0.01-0.05%, P≤0.020%, S≤0.010% and N≤0.008%, the remainder of the composition being iron and unavoidable impurities resulting from the smelting, and having a microstructure consisting of, in surface fraction, between 80% and 90% of martensite, the balance being ferrite and bainite.

公开(公告)号：US20230038535A1

公开(公告)日：2023-02-09

申请号：US17786625

申请日：2019-12-18

Applicant: ArcelorMittal

Inventor： Josée DRILLET

IPC: C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C23C2/06 ,  C23C2/40

Abstract: A steel sheet has a composition comprising 0.060%≤C≤0.085%, 1.8%≤Mn≤2.0%, 0.4%≤Cr≤0.6%, 0.1%≤Si≤0.5%, 0.010%≤Nb≤0.025%, 3.42N≤Ti≤0.035%, 0≤Mo≤0.030%, 0.020%≤Al≤0.060%, 0.0012%≤B≤0.0030%, S≤0.005%, P≤0.050%, 0.002%≤N≤0.007% and optionally 0.0005%≤Ca≤0.005%, the remainder of the composition being iron and unavoidable impurities. The microstructure consists of 34% to 80% bainite, 10% to 16% martensite, and 10% to 50% of ferrite. The surface fraction of unrecrystallized ferrite, with respect to the whole structure, is of less than 30%. The martensite consists of self-tempered martensite and fresh martensite, the surface fraction of self-tempered martensite being comprised between 4% and 10%.