HOT-ROLLED STEEL SHEET, HIGH-STRENGTH COLD-ROLLED STEEL SHEET, AND MANUFACTURING METHODS THEREFOR

Title:

HOT-ROLLED STEEL SHEET, HIGH-STRENGTH COLD-ROLLED STEEL SHEET, AND MANUFACTURING METHODS THEREFOR

Document Type and Number:

WIPO Patent Application WO/2020/004561

Kind Code:

A1

Abstract:

Provided are: a high-strength cold-rolled steel sheet for which little load is required during cold working and which has superior formability and ductility such that certain conditions are satisfied with regard to the evaluation of formability and retained austenite; a hot-rolled steel sheet which serves as the material of the high-strength cold-rolled steel sheet; and manufacturing methods for the high-strength cold-rolled steel sheet and the hot-rolled steel sheet, each of the manufacturing methods including a first step for subjecting a rolling material to rough rolling with a total rolling reduction of 30% or greater, a second step for subjecting the rolling material to finish rolling with a total rolling reduction of 40% or greater using a plurality of different diameter rolls having diameters that differ from one another in a temperature environment of 800ºC or greater, and a third step for winding the rolled product in a temperature environment of 700ºC or greater.

Inventors:

KATSURA KEISHI (JP)
IWAMOTO NOBUHIRO (JP)
TAKEMATSU SHINICHI (JP)
YOSHIDA FUYUKI (JP)
YAMASHITA TAKASHI (JP)
ANRAKU KAZUHIKO (JP)

Application Number:

PCT/JP2019/025644

Publication Date:

January 02, 2020

Filing Date:

June 27, 2019

Export Citation:

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Assignee:

TOYO KOHAN CO LTD (JP)
NAKAYAMA STEEL WORKS LTD (JP)

International Classes:

C21D9/46; B21B1/22; B21B1/26; B21B3/00; C22C38/00; C22C38/58; C21D9/48

Domestic Patent References:

WO2013047819A1	2013-04-04
WO2011111333A1	2011-09-15

Foreign References:

JP2004183057A	2004-07-02
JP2011168861A	2011-09-01
JP2015151576A	2015-08-24
JP2006207018A	2006-08-10
JP2017128750A	2017-07-27
JP2005262255A	2005-09-29
JP2005230896A	2005-09-02