Steel Sheet And Plated Steel Sheet

Abstract: The present invention relates to a steel sheet and a plated steel sheet, each of which has high LME resistance. The steel sheet according to the present invention is characterized in that: the steel sheet has a tensile strength of 780 MPa or more; the steel sheet has a specific chemical component; the depth, at which the C concentration as measured by GDS is 0.05% or less, from the surface of the steel sheet in the thickness direction of the steel sheet is 8 µm or more; the thickness of a layer, in which the area ratio of the ferrite phase is 90% or more, in the thickness direction of the steel sheet from the surface of the steel sheet is 8 µm or more; and the solid solution amount of Si metal and Al metal in the ferrite phase is 0.3% or more in total at the position of 4 µm from the surface of the steel sheet in the thickness direction of the steel sheet.

Patent Information

Application #

Filing Date

27 October 2025

Publication Number

48/2025

Publication Type

INA

Invention Field

METALLURGY

Status

Email

Parent Application

Applicants

NIPPON STEEL CORPORATION

6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

Inventors

1. KIREKAWA, Naoto

c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

2. MITSUNOBU, Takuya

c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

3. URANAKA, Masaaki

c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

4. TAKEBAYASHI, Hiroshi

c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

Specification

Documents

Application Documents

#	Name	Date
1	202517103253-TRANSLATIOIN OF PRIOIRTY DOCUMENTS ETC. [27-10-2025(online)].pdf	2025-10-27
2	202517103253-STATEMENT OF UNDERTAKING (FORM 3) [27-10-2025(online)].pdf	2025-10-27
3	202517103253-REQUEST FOR EXAMINATION (FORM-18) [27-10-2025(online)].pdf	2025-10-27
4	202517103253-PROOF OF RIGHT [27-10-2025(online)].pdf	2025-10-27
5	202517103253-PRIORITY DOCUMENTS [27-10-2025(online)].pdf	2025-10-27
6	202517103253-POWER OF AUTHORITY [27-10-2025(online)].pdf	2025-10-27
7	202517103253-FORM 18 [27-10-2025(online)].pdf	2025-10-27
8	202517103253-FORM 1 [27-10-2025(online)].pdf	2025-10-27
9	202517103253-DRAWINGS [27-10-2025(online)].pdf	2025-10-27
10	202517103253-DECLARATION OF INVENTORSHIP (FORM 5) [27-10-2025(online)].pdf	2025-10-27
11	202517103253-COMPLETE SPECIFICATION [27-10-2025(online)].pdf	2025-10-27