Title:
HIGH-STRENGTH HOT-DIP GALVANIZED STEEL PLATE HAVING EXCELLENT IMPACT RESISTANCE AND METHOD FOR PRODUCING SAME, AND HIGH-STRENGTH ALLOYED HOT-DIP GALVANIZED STEEL SHEET AND METHOD FOR PRODUCING SAME
Document Type and Number:
WIPO Patent Application WO/2013/047755
Kind Code:
A1
Abstract:
This base steel sheet has a hot-dip galvanized layer formed on the surface, and the volume fraction of a retained austenite phase of the steel sheet structure in a range of 1/8 of the sheet thickness to 3/8 of the sheet thickness, centered around 1/4 of the sheet thickness, from the surface, is not more than 5%, and the total volume fraction of a bainite phase, a bainitic ferrite phase, a fresh martensite phase, and a tempered martensite phase is not less than 40%. The average effective grain size is not more than 5.0 μm, and the maximum effective grain size is not more than 20 μm. A decarburized layer with a thickness of 0.01 to 10.0 μm is formed on a surface section, the density of oxides, which are dispersed in the decarburized layer is 1.0 × 1012 to 1.0 × 1016 oxides/m2, and the average particle size of the oxides is not more than 500 nm.
Inventors:
KAWATA HIROYUKI (JP)
MARUYAMA NAOKI (JP)
MURASATO AKINOBU (JP)
MINAMI AKINOBU (JP)
YASUI TAKESHI (JP)
KUWAYAMA TAKUYA (JP)
BAN HIROYUKI (JP)
HIRAMATSU KAORU (JP)
MARUYAMA NAOKI (JP)
MURASATO AKINOBU (JP)
MINAMI AKINOBU (JP)
YASUI TAKESHI (JP)
KUWAYAMA TAKUYA (JP)
BAN HIROYUKI (JP)
HIRAMATSU KAORU (JP)
Application Number:
PCT/JP2012/075098
Publication Date:
April 04, 2013
Filing Date:
September 28, 2012
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; B21B1/26; B21B3/00; C21D9/46; C22C18/04; C22C38/06; C22C38/58; C23C2/02; C23C2/06; C23C2/28
Foreign References:
| JP2011117041A | 2011-06-16 | |||
| JP2011111675A | 2011-06-09 | |||
| JP2011153349A | 2011-08-11 | |||
| JP2007211279A | 2007-08-23 | |||
| JP2006233333A | 2006-09-07 | |||
| JP2005256020A | 2005-09-22 | |||
| JP2010156016A | 2010-07-15 | |||
| JP2008285741A | 2008-11-27 | |||
| JP2008266758A | 2008-11-06 | |||
| JP2006342387A | 2006-12-21 | |||
| JPH09143570A | 1997-06-03 | |||
| JPH07150294A | 1995-06-13 | |||
| JP2009068039A | 2009-04-02 | |||
| JP2008255441A | 2008-10-23 | |||
| JP2004300452A | 2004-10-28 | |||
| JP2004277858A | 2004-10-07 | |||
| JPH10130776A | 1998-05-19 |
Other References:
See also references of EP 2762589A4
Attorney, Agent or Firm:
KOKUBUN, Takayoshi (JP)
Takayoshi Kokubu (JP)
Takayoshi Kokubu (JP)
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Claims: