Cold Rolled Steel Sheet And Method For Manufacturing Same

Abstract: The present invention is a cold-rolled steel sheet characterized by having a prescribed chemical composition and being such that: a steel structure is, in terms of areal percentage, 90.0-99.5% martensite, 0-5% ferrite, and 0.5-7.0% residual austenite, the remainder being bainite; the percentage of tempered martensite in the total martensite is 80-100%; the maximum value of a curvature 1/R represented by formula (1) below and obtained by measuring the shape of a region equal to the full width by a length of 300 mm is 0.010 or less; and the tensile strength is 1470 MPa or more.

Patent Information

Application #

Filing Date

04 December 2023

Publication Number

10/2024

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. YOKOYAMA, Takafumi

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

2. HIROSE, Satoshi

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

3. TSURUOKA, Hiroyuki

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

Specification

Documents

Application Documents

#	Name	Date
1	202317082383-TRANSLATIOIN OF PRIOIRTY DOCUMENTS ETC. [04-12-2023(online)].pdf	2023-12-04
2	202317082383-STATEMENT OF UNDERTAKING (FORM 3) [04-12-2023(online)].pdf	2023-12-04
3	202317082383-REQUEST FOR EXAMINATION (FORM-18) [04-12-2023(online)].pdf	2023-12-04
4	202317082383-PROOF OF RIGHT [04-12-2023(online)].pdf	2023-12-04
5	202317082383-PRIORITY DOCUMENTS [04-12-2023(online)].pdf	2023-12-04
6	202317082383-POWER OF AUTHORITY [04-12-2023(online)].pdf	2023-12-04
7	202317082383-FORM 18 [04-12-2023(online)].pdf	2023-12-04
8	202317082383-FORM 1 [04-12-2023(online)].pdf	2023-12-04
9	202317082383-DRAWINGS [04-12-2023(online)].pdf	2023-12-04
10	202317082383-DECLARATION OF INVENTORSHIP (FORM 5) [04-12-2023(online)].pdf	2023-12-04
11	202317082383-COMPLETE SPECIFICATION [04-12-2023(online)].pdf	2023-12-04
12	202317082383-FORM 3 [04-04-2024(online)].pdf	2024-04-04