Steel Sheet And Member, And Production Methods Therefor

Abstract: The present invention provides a steel sheet which combines high strength, high YS, excellent ductility, and excellent bendability. The steel sheet has a prescribed component composition and steel structure. In particular, in the steel structure, the following are properly controlled: the retained austenite particle number density; the particle ratio of particles having as aspect ratio of 3 or less; the average C concentration of particles having an aspect ratio of 3 or less; the inter-particle distance average value of particles having an aspect ratio of 3 or less; the inter-particle distance maximum value of particles having an aspect ratio of 3 or less; and [Mn]C/[Mn].

Patent Information

Application #

Filing Date

24 June 2025

Publication Number

27/2025

Publication Type

INA

Invention Field

METALLURGY

Status

Email

Parent Application

Applicants

JFE STEEL CORPORATION

2-3, Uchisaiwai-cho 2-chome, Chiyoda-ku, Tokyo 1000011

Inventors

1. HATA Katsuya

c/o Intellectual Property Dept., JFE STEEL CORPORATION, 2-3, Uchisaiwai-cho 2-chome, Chiyoda-ku, Tokyo 1000011

2. TERASHIMA Shotaro

c/o Intellectual Property Dept., JFE STEEL CORPORATION, 2-3, Uchisaiwai-cho 2-chome, Chiyoda-ku, Tokyo 1000011

3. NAKAGAITO Tatsuya

c/o Intellectual Property Dept., JFE STEEL CORPORATION, 2-3, Uchisaiwai-cho 2-chome, Chiyoda-ku, Tokyo 1000011

4. TSUDA Seisuke

c/o Intellectual Property Dept., JFE STEEL CORPORATION, 2-3, Uchisaiwai-cho 2-chome, Chiyoda-ku, Tokyo 1000011

Specification

Documents

Application Documents

#	Name	Date
1	202517060132-TRANSLATIOIN OF PRIOIRTY DOCUMENTS ETC. [24-06-2025(online)].pdf	2025-06-24
2	202517060132-STATEMENT OF UNDERTAKING (FORM 3) [24-06-2025(online)].pdf	2025-06-24
3	202517060132-REQUEST FOR EXAMINATION (FORM-18) [24-06-2025(online)].pdf	2025-06-24
4	202517060132-PROOF OF RIGHT [24-06-2025(online)].pdf	2025-06-24
5	202517060132-PRIORITY DOCUMENTS [24-06-2025(online)].pdf	2025-06-24
6	202517060132-POWER OF AUTHORITY [24-06-2025(online)].pdf	2025-06-24
7	202517060132-FORM 18 [24-06-2025(online)].pdf	2025-06-24
8	202517060132-FORM 1 [24-06-2025(online)].pdf	2025-06-24
9	202517060132-DRAWINGS [24-06-2025(online)].pdf	2025-06-24
10	202517060132-DECLARATION OF INVENTORSHIP (FORM 5) [24-06-2025(online)].pdf	2025-06-24
11	202517060132-COMPLETE SPECIFICATION [24-06-2025(online)].pdf	2025-06-24
12	202517060132-FORM 3 [14-11-2025(online)].pdf	2025-11-14