	US 12,134,810 B2
	Steel sheet for hot stamping and hot-stamping formed body
Daisuke Maeda, Tokyo (JP); Yuri Toda, Tokyo (JP); and Shingo Fujinaka, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 17/801,145
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed May 7, 2021, PCT No. PCT/JP2021/017509 § 371(c)(1), (2) Date Aug. 19, 2022, PCT Pub. No. WO2021/230150, PCT Pub. Date Nov. 18, 2021.
Claims priority of application No. 2020-084592 (JP), filed on May 13, 2020; and application No. 2020-084593 (JP), filed on May 13, 2020.
Prior Publication US 2023/0081832 A1, Mar. 16, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C22C 38/02 (2006.01); B21D 22/02 (2006.01); C22C 38/00 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/08 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); C22C 38/18 (2006.01)

CPC C22C 38/18 (2013.01) [B21D 22/022 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01)]

10 Claims

1. A steel sheet for hot stamping comprising, as a chemical composition, by mass %:

C: 0.15 to 0.50%;

Si: 0.0010% to 3.000%;

Mn: 0.30% to 3.00%;

Al: 0.0002% to 2.000%;

P: 0.100% or less;

S: 0.1000% or less;

N: 0.0100% or less;

Nb: 0% to 0.15%;

Ti: 0% to 0.15%;

V: 0% to 0.15%;

Mo: 0% to 1.0%;

Cr: 0% to 1.0%;

Cu: 0% to 1.0%;

Ni: 0% to 1.0%;

B: 0% to 0.0100%;

Ca: 0% to 0.010%;

REM: 0% to 0.30%; and

a remainder consisting of Fe and an impurity,

wherein the steel sheet for hot stamping has a metallographic structure consisting of, by area ratio, a total of 20% to 80% of ferrite, granular bainite, bainite, and martensite and a remainder in microstructure consisting of pearlite and a carbide,

in a texture between a surface and a sheet thickness ¼ position from the surface, a ratio between a pole density of an orientation group consisting of {001}<1-10> to {001}<−1-10> and a pole density of an orientation group consisting of {111}<1-10> to {111}<−1-12> is less than 1.5, and

in a texture between the sheet thickness ¼ position from the surface and a sheet thickness ½ position from the surface, a ratio between a pole density of an orientation group consisting of {001}<1-10> to {001}<−1-10> and a pole density of an orientation group consisting of {111}<1-10> to {111}<−1-12> is less than 2.0.