Hot Rolled Steel Sheet

Abstract: With respect to a hot-rolled steel sheet according to the present invention, the metal structure at 1/4 the sheet thickness from the surface comprises, in area%, 2.0% to 30.0% of ferrite, 60.0% to 93.0% of bainite and 5.0% to 20.0% of martensite, while being in contact with a 30° grain boundary; if Ia is the maximum value of the GAIQ of the ferrite, the relative GAIQ is Ia/3 or less; the area ratio of the martensite having a crystal grain size of 2.0 µm or more is 5.0% or more; and the tensile strength is 980 MPa or more.

Patent Information

Application #

Filing Date

21 May 2024

Publication Number

50/2024

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. YABU Shohei

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

2. KUWAYAMA Takuya

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

Specification

Documents

Application Documents

#	Name	Date
1	202417039650-TRANSLATIOIN OF PRIOIRTY DOCUMENTS ETC. [21-05-2024(online)].pdf	2024-05-21
2	202417039650-STATEMENT OF UNDERTAKING (FORM 3) [21-05-2024(online)].pdf	2024-05-21
3	202417039650-REQUEST FOR EXAMINATION (FORM-18) [21-05-2024(online)].pdf	2024-05-21
4	202417039650-PROOF OF RIGHT [21-05-2024(online)].pdf	2024-05-21
5	202417039650-PRIORITY DOCUMENTS [21-05-2024(online)].pdf	2024-05-21
6	202417039650-POWER OF AUTHORITY [21-05-2024(online)].pdf	2024-05-21
7	202417039650-NOTIFICATION OF INT. APPLN. NO. & FILING DATE (PCT-RO-105-PCT Pamphlet) [21-05-2024(online)].pdf	2024-05-21
8	202417039650-FORM 18 [21-05-2024(online)].pdf	2024-05-21
9	202417039650-FORM 1 [21-05-2024(online)].pdf	2024-05-21
10	202417039650-DECLARATION OF INVENTORSHIP (FORM 5) [21-05-2024(online)].pdf	2024-05-21
11	202417039650-COMPLETE SPECIFICATION [21-05-2024(online)].pdf	2024-05-21
12	202417039650-FORM 3 [07-10-2024(online)].pdf	2024-10-07