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.