Title:
HIGH-STRENGTH GALVANNEALED STEEL SHEET OF HIGH BAKE HARDENABILITY, HIGH-STRENGTH ALLOYED GALVANNEALED STEEL SHEET, AND METHOD FOR MANUFACTURING SAME
Document Type and Number:
WIPO Patent Application WO/2013/047821
Kind Code:
A1
Abstract:
The present invention relates to a steel which contains C, Si, Mn, P, S, Al, N, and O each, a remainder of which is formed of Fe and inevitable impurities. In a range between a 1/8 thickness around a 1/4 plate thickness from a surface of a base material steel sheet to a 3/8 thickness around the 1/4 plate thickness from the surface, a formation of the base material contains a residual austenite aspect with a volume fraction of 3% or higher, a ferrite phase of 50% or lower, and a hard aspect of 40% or higher. An average dislocation density is 5×1013/m2 or higher, and the solution C amount contained in the residual austenite aspect is from 0.70 wt% to 1.00 wt%. A random strength ratio of an X ray of an FCC iron of an aggregate structure of the residual austenite aspect is 3.0 or below. A ratio of a particle diameter with respect to a rolling direction of the residual austenite aspect to a particle diameter with respect to a plate width direction is from 0.75 to 1.33. A galvannealed layer is formed at a surface of the base material. The plate thickness is from 0.6 mm to 5.0 mm.
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/JP2012/075218
Publication Date:
April 04, 2013
Filing Date:
September 28, 2012
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; B21B3/00; C21D9/46; C22C18/04; C22C38/06; C22C38/58; C23C2/02; C23C2/06; C23C2/28
Foreign References:
| JP2010209433A | 2010-09-24 | |||
| JP2010202949A | 2010-09-16 | |||
| JP2002533567A | 2002-10-08 | |||
| JP2008144233A | 2008-06-26 | |||
| JP2004263270A | 2004-09-24 | |||
| JP2003277884A | 2003-10-02 | |||
| JP2005023348A | 2005-01-27 | |||
| JP2003049242A | 2003-02-21 | |||
| JP2001247946A | 2001-09-14 |
Other References:
SCRIPTA METALLURGICA ET MATERIALIA, vol. 24, 1990, pages 509 - 51,4
Attorney, Agent or Firm:
KOKUBUN, Takayoshi (JP)
Takayoshi Kokubu (JP)
Takayoshi Kokubu (JP)
Download PDF:
Claims:
Previous Patent: HOT-DIP GALVANIZED STEEL SHEET AND PROCESS FOR PRODUCING SAME
Next Patent: COMMUNICATION SYSTEM, METHOD AND APPARATUS
Next Patent: COMMUNICATION SYSTEM, METHOD AND APPARATUS