US 11,795,520 B2
Hot-pressed member, method for manufacturing the same, and method for manufacturing steel sheet for hot-pressed member
Shimpei Yoshioka, Tokyo (JP); Yoshihiko Ono, Tokyo (JP); Katsutoshi Takashima, Tokyo (JP); Takayuki Futatsuka, Tokyo (JP); and Kentaro Sato, Tokyo (JP)
Assigned to JFE STEEL CORPORATION, Tokyo (JP)
Appl. No. 17/432,349
Filed by JFE STEEL CORPORATION, Tokyo (JP)
PCT Filed Nov. 21, 2019, PCT No. PCT/JP2019/045678
§ 371(c)(1), (2) Date Aug. 19, 2021,
PCT Pub. No. WO2020/170530, PCT Pub. Date Aug. 27, 2020.
Claims priority of application No. 2019-030344 (JP), filed on Feb. 22, 2019.
Prior Publication US 2022/0056552 A1, Feb. 24, 2022
Int. Cl. C21D 8/02 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C23C 2/06 (2006.01); C23C 2/02 (2006.01); C21D 9/48 (2006.01); B32B 15/01 (2006.01); C21D 6/00 (2006.01); C22C 38/00 (2006.01); C22C 38/08 (2006.01); C22C 38/10 (2006.01); C22C 38/12 (2006.01); C22C 38/16 (2006.01); C22C 38/26 (2006.01); C22C 38/28 (2006.01); C22C 38/38 (2006.01); C22C 38/60 (2006.01); C23C 2/40 (2006.01); C23C 2/12 (2006.01)
CPC C21D 9/48 (2013.01) [B32B 15/012 (2013.01); B32B 15/013 (2013.01); C21D 6/002 (2013.01); C21D 6/005 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 8/0263 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/008 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/10 (2013.01); C22C 38/12 (2013.01); C22C 38/16 (2013.01); C22C 38/26 (2013.01); C22C 38/28 (2013.01); C22C 38/38 (2013.01); C22C 38/60 (2013.01); C23C 2/40 (2013.01); C21D 2211/008 (2013.01); C23C 2/06 (2013.01); C23C 2/12 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A hot-pressed member comprising a steel sheet as a base material, the steel sheet having a chemical composition comprising, by mass %:
C: 0.28% or greater and less than 0.50%;
Si: 0.01% or greater and 2.0% or less;
Mn: 0.5% or greater and 3.5% or less;
P: 0.05% or less;
S: 0.01% or less;
Al: 0.01% or greater and 1.00% or less;
N: 0.01% or less;
O: 0.0013% or less; and
a balance being Fe and incidental impurities,
wherein the hot-pressed member has a microstructure in which martensite is present in a volume fraction of 70% or greater, and a number density of inclusions having a longest diameter of 25 μm or greater is 0.02/mm2 or less, and
the hot-pressed member has a tensile strength of 1.8 GPa or greater.