Steel Plate

Abstract: Provided is a steel plate characterized by having a predetermined chemical composition, and characterized in that: the metal structure includes, in area%, 90.0% or more martensite and 3.0% or less retained austenite; the average grain size of former austenite grains is 30.0 µm or less; and when a region surrounded by grain boundaries having an orientation difference of 15° or more in the martensite is defined as crystal grains, the proportion of the crystal grains in which the in-grain orientation difference is 4° or more is, in area%, 45.0-70.0%.

Patent Information

Application #

Filing Date

08 August 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. OSANAI, Takumi

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	202517075728-TRANSLATIOIN OF PRIOIRTY DOCUMENTS ETC. [08-08-2025(online)].pdf	2025-08-08
2	202517075728-STATEMENT OF UNDERTAKING (FORM 3) [08-08-2025(online)].pdf	2025-08-08
3	202517075728-REQUEST FOR EXAMINATION (FORM-18) [08-08-2025(online)].pdf	2025-08-08
4	202517075728-PROOF OF RIGHT [08-08-2025(online)].pdf	2025-08-08
5	202517075728-PRIORITY DOCUMENTS [08-08-2025(online)].pdf	2025-08-08
6	202517075728-POWER OF AUTHORITY [08-08-2025(online)].pdf	2025-08-08
7	202517075728-FORM 18 [08-08-2025(online)].pdf	2025-08-08
8	202517075728-FORM 1 [08-08-2025(online)].pdf	2025-08-08
9	202517075728-DECLARATION OF INVENTORSHIP (FORM 5) [08-08-2025(online)].pdf	2025-08-08
10	202517075728-COMPLETE SPECIFICATION [08-08-2025(online)].pdf	2025-08-08