HIGH-STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING SAME

Title:

HIGH-STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING SAME

Document Type and Number:

WIPO Patent Application WO/2020/158065

Kind Code:

A1

Abstract:

The purpose of the present invention is to provide: a high-strength steel sheet having excellent shearing burr suppression and workability; and a method for manufacturing the same.　Provided is a high-strength steel sheet having a prescribed component composition and a steel structure in which, in a sheet thickness cross section in the rolling direction: the area percentage of ferrite is 5-30%; the combined area percentage of tempered martensite and bainite is 40-90%; pearlite is 0-5%; the combined area percentage of fresh martensite and a residue γ is 5-30%; the ratio of the combined area percentage of the fresh martensite and the residue γ to the combined area percentage of the tempered martensite, bainite and pearlite is 0.5 or lower; and the proportion of the fresh martensite and the residue γ adjacent to ferrite from among the fresh martensite and the residue γ is 30% or higher in terms of the combined area percentage. The yield strength of said high-strength steel sheet is 550 MPa or higher.

Inventors:

YANG LINGLING (JP)
NAKAGAITO TATSUYA (JP)

Application Number:

PCT/JP2019/041131

Publication Date:

August 06, 2020

Filing Date:

October 18, 2019

Export Citation:

Click for automatic bibliography generation Help

Assignee:

JFE STEEL CORP (JP)

International Classes:

C21D9/46; C22C38/00; C22C38/14; C22C38/60; C23C2/06; C23C2/28; C23C2/40

Domestic Patent References:

WO2013018726A1	2013-02-07
WO2013018739A1	2013-02-07
WO2017108959A1	2017-06-29

Foreign References:

JP2016141858A	2016-08-08
JPH04120242A	1992-04-21
JP2011111673A	2011-06-09
JP5354135B2	2013-11-27
JP2011168880A	2011-09-01

Other References: