COLD ROLLED STEEL SHEET FOR ZIRCONIUM-BASED CHEMICAL CONVERSION TREATMENT, METHOD FOR PRODUCING SAME, ZIRCONIUM-BASED CHEMICAL CONVERSION-TREATED STEEL SHEET, AND METHOD FOR PRODUCING SAME

Title:

COLD ROLLED STEEL SHEET FOR ZIRCONIUM-BASED CHEMICAL CONVERSION TREATMENT, METHOD FOR PRODUCING SAME, ZIRCONIUM-BASED CHEMICAL CONVERSION-TREATED STEEL SHEET, AND METHOD FOR PRODUCING SAME

Document Type and Number:

WIPO Patent Application WO/2020/095682

Kind Code:

A1

Abstract:

Provided is a cold rolled steel sheet for zirconium-based chemical conversion treatment, which is inexpensive, which contains Si and Mn, and which exhibits excellent zirconium-based chemical conversion treatment properties even if Si-based oxides or Si-Mn-based oxides are present at relatively large quantities at the surface of the steel sheet. This cold rolled steel sheet for zirconium-based chemical conversion treatment has a constituent composition that contains, in terms of mass%, 0.05-0.30% of C, 0.01-1.4% of Si, 0.14-3.2% of Mn, 0.10% or less of P and 0.01% or less of S, with the remainder comprising Fe and unavoidable impurities. The Si/Mn mass ratio in the steel is 0.10-0.7. The surface coverage ratio of a surface layer of the steel sheet by oxides having a Si amount of 10 mass% or more is 40% or less.

Inventors:

TAKEYAMA HAYATO (JP)
MATSUDA TAKESHI (JP)

Application Number:

PCT/JP2019/041551

Publication Date:

May 14, 2020

Filing Date:

October 23, 2019

Export Citation:

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Assignee:

JFE STEEL CORP (JP)

International Classes:

C22C38/00; C21D9/46; C22C38/04; C22C38/60; C23C22/34; C23C22/78

Domestic Patent References:

WO2010004651A1	2010-01-14
WO2006109489A1	2006-10-19

Foreign References:

JP2003226920A	2003-08-15
JPH04276060A	1992-10-01
JP2015098620A	2015-05-28
JP2005290440A	2005-10-20
JP2012132092A	2012-07-12
JP6210175B2	2017-10-11
JP2003155578A	2003-05-30
JP5274560B2	2013-08-28

Other References: