Title:
HIGH-STRENGTH MOLTEN GALVANIZED STEEL SHEET AND METHOD FOR PRODUCTION THEREOF
Document Type and Number:
WIPO Patent Application WO/2016/031166
Kind Code:
A1
Abstract:
Provided are a high-strength molten galvanized steel sheet having tensile strength (TS) of 1,300 MPa or higher, as well as exceptional ductility and in-plane homogeneity; and a method for producing said sheet. A high-strength molten galvanized steel sheet having a microstructure that has C, Si, Mn, etc., in a specific composition; the components being contained such that the Ti content [Ti] and the N content [N] satisfy the relationship [Ti]>4[N]; said sheet having a martensite content of 60 to 90% by area inclusive, a polygonal ferrite content of 5 to 40% by area inclusive, and a residual austenite content of less than 3% (including 0%) by area; the average hardness of the martensite being 450 to 600 inclusive, expressed as the Vickers hardness; the average crystal grain diameter of the martensite being 10 μm or less; and the standard deviation of the crystal grain diameter of the martensite being 4.0 μm or less.
Inventors:
HASEGAWA HIROSHI (JP)
FUJITA KOICHIRO (JP)
FUJITA KOICHIRO (JP)
Application Number:
PCT/JP2015/004050
Publication Date:
March 03, 2016
Filing Date:
August 14, 2015
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C22C38/00; C21D9/48; C22C38/14; C22C38/58; C23C2/06; C23C2/28; C23C2/40; C22C18/04
Foreign References:
| JP2010255094A | 2010-11-11 | |||
| JP2014005514A | 2014-01-16 | |||
| JP2010275628A | 2010-12-09 | |||
| JP2009179852A | 2009-08-13 |
Other References:
See also references of EP 3187608A4
Attorney, Agent or Firm:
KUMASAKA, Akira et al. (JP)
Akira Kumasaka (JP)
Akira Kumasaka (JP)
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