Hot Rolled Steel Sheet

Abstract: This hot-rolled steel sheet has a specific chemical composition; and the metal structure of the inner region of this hot-rolled steel sheet contains, in area ratios, a total of 40% to 80% of martensite and/or bainite, and 20% to 60% of ferrite, with the remainder structure being less than 5% by area. The ratio as/ac of the ferrite area ratio as in the surface region to the ferrite area ratio ac in the inner region is from 1.15 to 2.50; the hardness difference ratio (1 - Hvs/Hvc) of the Vickers hardness Hvs in the surface region to the Vickers hardness Hvc in the inner region is 0.20 or less; and the tensile strength is 980 MPa or more.

Patent Information

Application #

Filing Date

29 January 2024

Publication Number

41/2024

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. TOYODA Takeshi

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

2. SHUTO Hiroshi

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

3. NIKKUNI Daisuke

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

Specification

Documents

Application Documents

#	Name	Date
1	202417005710-TRANSLATIOIN OF PRIOIRTY DOCUMENTS ETC. [29-01-2024(online)].pdf	2024-01-29
2	202417005710-STATEMENT OF UNDERTAKING (FORM 3) [29-01-2024(online)].pdf	2024-01-29
3	202417005710-PROOF OF RIGHT [29-01-2024(online)].pdf	2024-01-29
4	202417005710-POWER OF AUTHORITY [29-01-2024(online)].pdf	2024-01-29
5	202417005710-FORM 1 [29-01-2024(online)].pdf	2024-01-29
6	202417005710-DECLARATION OF INVENTORSHIP (FORM 5) [29-01-2024(online)].pdf	2024-01-29
7	202417005710-COMPLETE SPECIFICATION [29-01-2024(online)].pdf	2024-01-29
8	202417005710-FORM 3 [01-07-2024(online)].pdf	2024-07-01
9	202417005710-FORM 18 [06-08-2025(online)].pdf	2025-08-06