Steel Sheet And Method For Producing Same

Abstract: Provided is a steel sheet that characteristically has: a prescribed chemical composition; a metal structure containing, on an area% basis, at least 90.0% martensite and not more than 3.0% retained austenite; an average grain size for prior austenite grains of not more than 30.0 µm; and a standard deviation on the grain size of the prior austenite grains of at least 4.0 µm. Also provided is a method for producing this steel sheet.

Patent Information

Application #

Filing Date

02 September 2025

Publication Number

38/2025

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. KOBAYASHI, Shunsuke

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

2. MURATA, Shinichi

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

3. SAKURADA, Eisaku

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

Specification

Documents

Application Documents

#	Name	Date
1	202517083241-TRANSLATIOIN OF PRIOIRTY DOCUMENTS ETC. [02-09-2025(online)].pdf	2025-09-02
2	202517083241-STATEMENT OF UNDERTAKING (FORM 3) [02-09-2025(online)].pdf	2025-09-02
3	202517083241-REQUEST FOR EXAMINATION (FORM-18) [02-09-2025(online)].pdf	2025-09-02
4	202517083241-PROOF OF RIGHT [02-09-2025(online)].pdf	2025-09-02
5	202517083241-PRIORITY DOCUMENTS [02-09-2025(online)].pdf	2025-09-02
6	202517083241-POWER OF AUTHORITY [02-09-2025(online)].pdf	2025-09-02
7	202517083241-FORM 18 [02-09-2025(online)].pdf	2025-09-02
8	202517083241-FORM 1 [02-09-2025(online)].pdf	2025-09-02
9	202517083241-DECLARATION OF INVENTORSHIP (FORM 5) [02-09-2025(online)].pdf	2025-09-02
10	202517083241-COMPLETE SPECIFICATION [02-09-2025(online)].pdf	2025-09-02