HIGH-TENSION/HOT-ROLLED STEEL SHEET HAVING EXCELLENT WORKABILITY, AND METHOD FOR PRODUCING SAME

Title:

HIGH-TENSION/HOT-ROLLED STEEL SHEET HAVING EXCELLENT WORKABILITY, AND METHOD FOR PRODUCING SAME

Document Type and Number:

WIPO Patent Application WO/2011/162418

Kind Code:

A1

Abstract:

Provided is a high-tension/hot-rolled steel sheet which has both strength and workability (stretch flangeability). The high-tension/hot-rolled steel sheet has: a composition comprising, by mass%, 0.005% to 0.050% of C, 0.2% or less of Si, 0.8% or less of Mn, 0.025% or less of P, 0.01% or less of S, 0.01% or less of N, 0.06% or less of Al, and 0.05% to 0.10% of Ti such that S, N, and Ti satisfy Ti≥0.04+(N/14×48+S/32×48), and with Fe and inevitable impurities as the balance; a matrix in which the ferrite phase is 95% or more by surface area percentage with respect to the overall structure; a structure in which carbide microparticles comprising Ti and having an average grain size of less than 10 nm are dispersed and precipitated, and the volume ratio of the carbide microparticles with respect to the overall structure is 0.0007 or greater; a tensile strength of 590 MPa or greater; and excellent workability.

Inventors:

ARIGA TAMAKO (JP)
NAKAJIMA KATSUMI (JP)
FUNAKAWA YOSHIMASA (JP)
MORIYASU NORIAKI (JP)
MURATA TAKAYUKI (JP)

Application Number:

PCT/JP2011/065134

Publication Date:

December 29, 2011

Filing Date:

June 24, 2011

Export Citation:

Click for automatic bibliography generation Help

Assignee:

JFE STEEL CORP (JP)
ARIGA TAMAKO (JP)
NAKAJIMA KATSUMI (JP)
FUNAKAWA YOSHIMASA (JP)
MORIYASU NORIAKI (JP)
MURATA TAKAYUKI (JP)

International Classes:

C22C38/14; C21D8/02; C21D9/46; C22C38/54

Foreign References:

JP2005154809A	2005-06-16
JP2002322539A	2002-11-08
JP2009052139A	2009-03-12
JPH04329848A	1992-11-18
JP2000328186A	2000-11-28
JP2002161340A	2002-06-04

Other References: