Title:
HIGH-TENSILE STEEL SHEET HAVING EXCELLENT LOW-TEMPERATURE TOUGHNESS IN WELD HEAT-AFFECTED ZONE, AND METHOD FOR MANUFACTURING SAME
Document Type and Number:
WIPO Patent Application WO/2016/068094
Kind Code:
A1
Abstract:
After a steel material that contains, in terms of mass%, 0.010-0.050% of C, 0.01-0.50% of Si, 1.80-3.50% of Mn, 0.012% or less of P, 0.0035% or less of S, 0.010-0.060% of sol. Al, 0.1-2.0% of Ni, 1.0-3.0% of Cr, 0.005-0.040% of Nb, 0.005-0.025% of Ti, and 0.0020-0.0050% of N and satisfies 35Cr+8Mn≥63 and 7Cr+18Mn≤63 is reheated to 1030-1200°C, hot rolling is performed with a cumulative draft of 30% or more at 950°C or higher and a cumulative draft of 30-70% at less than 950°C, and accelerated cooling to 600°C or lower is performed at 1.0°C/s or higher, thereby obtaining a high-tensile steel sheet that has a thickness of 35-100 mm and a yield stress of 460 MPa or more, and has excellent CTOD characteristics in a heat-affected zone that has been multi-pass welded.
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Inventors:
ICHIMIYA KATSUYUKI (JP)
HASE KAZUKUNI (JP)
HASE KAZUKUNI (JP)
Application Number:
PCT/JP2015/080154
Publication Date:
May 06, 2016
Filing Date:
October 27, 2015
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C22C38/00; C21D8/02; C22C38/58
Domestic Patent References:
| WO2010082361A1 | 2010-07-22 |
Foreign References:
| JP2011246768A | 2011-12-08 | |||
| JP2013019015A | 2013-01-31 | |||
| JP2010229453A | 2010-10-14 | |||
| JP2013095926A | 2013-05-20 | |||
| JP2000256777A | 2000-09-19 | |||
| JP2004323917A | 2004-11-18 | |||
| JP2009024228A | 2009-02-05 |
Attorney, Agent or Firm:
GINZA MARONIE P. C. (JP)
Patent business corporation Ginza horse chestnut patent firm (JP)
Patent business corporation Ginza horse chestnut patent firm (JP)
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