US 12,404,561 B2
Steel sheet and high strength press hardened steel part and method of manufacturing the same
Sebastian Cobo, Montigny-lès-Metz (FR); François Stouvenot, Maizieres les Metz (FR); and Emmanuel Lucas, Maizieres les Metz (FR)
Assigned to ArcelorMittal, Luxembourg (LU)
Appl. No. 18/557,348
Filed by ArcelorMittal, Luxembourg (LU)
PCT Filed Apr. 29, 2022, PCT No. PCT/IB2022/053986
§ 371(c)(1), (2) Date Oct. 26, 2023,
PCT Pub. No. WO2022/234413, PCT Pub. Date Nov. 10, 2022.
Claims priority of application No. PCT/IB2021/053731 (WO), filed on May 4, 2021.
Prior Publication US 2024/0218476 A1, Jul. 4, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. C21D 8/00 (2006.01); B32B 15/01 (2006.01); C21D 1/18 (2006.01); C21D 6/00 (2006.01); C21D 9/00 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/44 (2006.01); C22C 38/48 (2006.01); C22C 38/50 (2006.01); C22C 38/54 (2006.01)
CPC C21D 8/005 (2013.01) [B32B 15/01 (2013.01); C21D 1/18 (2013.01); C21D 6/004 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 9/0068 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/44 (2013.01); C22C 38/48 (2013.01); C22C 38/50 (2013.01); C22C 38/54 (2013.01); C21D 2211/008 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A steel sheet made of a steel having a composition comprising, by weight percent:

OG Complex Work Unit Math
and comprising optionally:

OG Complex Work Unit Math
a remainder of the composition being iron and unavoidable impurities resulting from processing;
the steel sheet having a microstructure comprising, in surface fraction, from 60% to 95% of ferrite, a rest being martensite-austenite islands, pearlite or bainite,
the steel sheet comprising from a bulk to the surface of the coated steel sheet:
the bulk, the bulk being topped by a skin layer occupying an outermost 10% of the thickness on either side of the bulk, the skin layer having a skin layer inclusion population wherein a surface fraction of oxides is equal to or less than 60*10−6.