STEEL SHEET, PLATED STEEL SHEET, METHOD FOR PRODUCING STEEL SHEET, AND METHOD FOR PRODUCING PLATED STEEL SHEET

Title:

STEEL SHEET, PLATED STEEL SHEET, METHOD FOR PRODUCING STEEL SHEET, AND METHOD FOR PRODUCING PLATED STEEL SHEET

Document Type and Number:

WIPO Patent Application WO/2013/121963

Kind Code:

A1

Abstract:

This steel sheet contains, in mass%, from 0.020% to 0.080% (inclusive) of C, from 0.01% to 0.10% (inclusive) of Si, from 0.80% to 1.80% (inclusive) of Mn and more than 0.10% but less than 0.40% of Al, and additionally contains from 0.005% to 0.095% (inclusive) of Nb and from 0.005% to 0.095% (inclusive) of Ti so that the total of Nb and Ti is from 0.030% to 0.100% (inclusive). The metal structure of this steel sheet is composed of ferrite, bainite and other phases; the area ratio of the ferrite is from 80% to 95%; and the area ratio of the bainite is from 5% to 20%. The total of the fractions of the other phases is less than 3%. This steel sheet has a tensile strength of 590 MPa or more and a fatigue strength ratio of 0.45 or more, said fatigue strength ratio being the fatigue strength relative to the tensile strength.

Inventors:

TANAKA HIROYUKI (JP)
HAYASHI KUNIO (JP)
OGAWA TOSHIO (JP)
GOTO KOICHI (JP)
NAKANO KAZUAKI (JP)

Application Number:

PCT/JP2013/052836

Publication Date:

August 22, 2013

Filing Date:

February 07, 2013

Export Citation:

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Assignee:

NIPPON STEEL & SUMITOMO METAL CORP (JP)

International Classes:

C22C38/00; C21D9/46; C22C38/14; C22C38/58; C23C2/02; C23C2/06; C23C2/28

Domestic Patent References:

WO2011025042A1

2011-03-03

Foreign References:

JP2010159466A	2010-07-22
JP2004204326A	2004-07-22
JP2004225109A	2004-08-12
JP2006152341A	2006-06-15
JPH0790483A	1995-04-04
JP2009299136A	2009-12-24
JP2006161111A	2006-06-22

Other References: