Title:
STEEL MATERIAL SUITABLE FOR USE IN SOUR ENVIRONMENT
Document Type and Number:
WIPO Patent Application WO/2020/166675
Kind Code:
A1
Abstract:
Provided is a steel material having a 110 ksi-grade yield strength and excellent SSC resistance. A steel material according to the present disclosure contains, in mass percentages, 0.15-0.45% of C, 0.05-1.00% of Si, 0.01-1.00% of Mn, 0.030% or less of P, 0.0050% or less of S, 0.005-0.100% of Al, 0.55-1.10% of Cr, 0.70-1.00% of Mo, 0.002-0.020% of Ti, 0.05-0.30% of V, 0.002-0.100% of Nb, 0.0005-0.0040% of B, 0.0100% or less of N, and less than 0.0020% of O, comprises Fe and impurities as the remainder thereof, and has a chemical composition fulfilling formula (1) disclosed in the description. The crystal grain size of prior austenite grains is 15.0 μm or less, and the average area of precipitates precipitated on the prior austenite grain boundaries is 12.5 × 10-3 μm2 or less. The yield strength is 758-862 MPa.
Inventors:
OTOME YOHEI (JP)
KAMITANI HIROKI (JP)
SOMA ATSUSHI (JP)
OE TARO (JP)
KOMATSUBARA NOBUAKI (JP)
ARAI YUJI (JP)
TAKABE HIDEKI (JP)
KAMITANI HIROKI (JP)
SOMA ATSUSHI (JP)
OE TARO (JP)
KOMATSUBARA NOBUAKI (JP)
ARAI YUJI (JP)
TAKABE HIDEKI (JP)
Application Number:
PCT/JP2020/005642
Publication Date:
August 20, 2020
Filing Date:
February 13, 2020
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
C21D8/10; C22C38/00; C22C38/54
Domestic Patent References:
| WO2008123422A1 | 2008-10-16 |
Foreign References:
| JP2011246798A | 2011-12-08 | |||
| JPS62253720A | 1987-11-05 | |||
| JPS59232220A | 1984-12-27 | |||
| JPH06322478A | 1994-11-22 | |||
| JPH08311551A | 1996-11-26 | |||
| JP2000256783A | 2000-09-19 | |||
| JP2000297344A | 2000-10-24 | |||
| JP2005350754A | 2005-12-22 | |||
| JP2012519238A | 2012-08-23 | |||
| JP2012026030A | 2012-02-09 |
Other References:
See also references of EP 3926058A4
Attorney, Agent or Firm:
ASCEND IP LAW FIRM (JP)
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