	US 12,134,808 B2
	Hot-stamping formed body
Daisuke Maeda, Tokyo (JP); Yuri Toda, Tokyo (JP); and Kazuo Hikida, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 17/603,270
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed May 13, 2020, PCT No. PCT/JP2020/019111 § 371(c)(1), (2) Date Oct. 12, 2021, PCT Pub. No. WO2020/241258, PCT Pub. Date Dec. 3, 2020.
Claims priority of application No. 2019-101984 (JP), filed on May 31, 2019.
Prior Publication US 2022/0195567 A1, Jun. 23, 2022
Int. Cl. C22C 38/00 (2006.01); B21D 22/02 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/12 (2006.01); C22C 38/28 (2006.01)

CPC C22C 38/001 (2013.01) [B21D 22/022 (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 38/12 (2013.01); C22C 38/28 (2013.01)]

3 Claims

1. A hot-stamping formed body comprising:

a steel sheet containing, as a chemical composition, by mass %,

C: 0.15% or more and less than 0.70%,

Si: 0.005% to 0.250%,

Mn: 0.30% to 3.00%,

sol. Al: 0.0002% to 0.500%,

P: 0.100% or less,

S: 0.1000% or less,

N: 0.0100% or less,

Nb: 0% to 0.150%,

Ti: 0% to 0.150%,

Mo: 0% to 1.000%,

Cr: 0% to 1.000%,

B: 0% to 0.0100%,

Ca: 0% to 0.010%,

REM: 0% to 0.30%, and

a remainder consisting of Fe and impurities; and

a plating layer provided on a surface of the steel sheet, the plating layer having an adhesion amount of 10 g/m²to 90 g/m²and a Ni content of 10 mass % to 25 mass %, and containing a remainder consisting of Zn and impurities,

wherein, in a surface layer region, which is a region from the surface of the steel sheet to a position at a depth of 50 μm from the surface, a metallographic structure has one or more of martensite, tempered martensite, and lower bainite as a primary phase, and with respect to the sum of the lengths of grain boundaries having a rotation angle of 57° to 63°, the lengths of grain boundaries having a rotation angle of 49° to 56°, the lengths of grain boundaries having a rotation angle of 4° to 12°, and the lengths of grain boundaries having a rotation angle of 64° to 72° with a <011> direction as a rotation axis among the grain boundaries of grains having a phase of a body-centered structure, the ratio of the lengths of the grain boundaries having a rotation angle of 64° to 72° is 35% or more.