Title:
COLD-ROLLED STEEL SHEET, METHOD FOR PRODUCING SAME, AND HOT-STAMP-MOLDED ARTICLE
Document Type and Number:
WIPO Patent Application WO/2014/024831
Kind Code:
A1
Abstract:
A cold-rolled steel sheet according to the present invention contains specific chemical components, wherein the metallic structure of the steel sheet comprises ferrite at an area ratio ranging from 30 to 90%, martensite at an area ratio of 0% or more and less than 20%, perlite at an area ratio ranging from 0 to 10%, retained austenite at a volume ratio ranging from 5 to 20% and a remainder structure made up by bainite both before and after hot stamping, and wherein the hardness of the retained austenite as measured on a nanoindenter fulfills the relationship represented by the formulae H2/H1 < 1.1 and σHM < 20 and the relationship represented by the formula TS × El ≥ 20000 MPa·% is fulfilled both before and after hot stamping.
Inventors:
NONAKA TOSHIKI (JP)
KATO SATOSHI (JP)
KAWASAKI KAORU (JP)
TOMOKIYO TOSHIMASA (JP)
KATO SATOSHI (JP)
KAWASAKI KAORU (JP)
TOMOKIYO TOSHIMASA (JP)
Application Number:
PCT/JP2013/071126
Publication Date:
February 13, 2014
Filing Date:
August 05, 2013
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; C21D9/46; C22C38/06; C22C38/58; C21D1/18; C21D9/00
Foreign References:
| JP2001152287A | 2001-06-05 | |||
| JP2011157583A | 2011-08-18 | |||
| JP2011102437A | 2011-05-26 | |||
| JPH07286213A | 1995-10-31 | |||
| JPS63166934A | 1988-07-11 | |||
| JPH06128688A | 1994-05-10 | |||
| JP2000319756A | 2000-11-21 | |||
| JP2005012043A | 2005-01-13 |
Other References:
See also references of EP 2881484A4
Attorney, Agent or Firm:
SHIGA Masatake et al. (JP)
Masatake Shiga (JP)
Masatake Shiga (JP)
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