Title:
STAINLESS STEEL AND OIL WELL STAINLESS STEEL MATERIAL
Document Type and Number:
WIPO Patent Application WO/2017/022374
Kind Code:
A1
Abstract:
Provided is a stainless steel that is superior in corrosion resistance and low temperature toughness. The stainless steel contains, in mass%, Cr by 15.5-18.0%, and one or two selected from the group consisting of Mo and W within a range satisfying formula (1). A matrix structure includes, in volume fraction, a tempered martensite phase by 40-80%, a ferrite phase by 10-50%, and an austenite phase by 1-15%. When a microscopic structural image of the matrix structure captured at a magnification of 100-times is arranged on an x-y coordinate system, and when each pixel in 1024×1024 is represented in gray scale, β defined in formula (2) is not smaller than 1.55. 1.0 ≤ Mo+0.5W ≤ 3.5 (1), wherein Mo and W are the contained amounts of Mo and W represented in mass%.
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Inventors:
TOMIO YUSAKU (JP)
KAIDO HIROSHI (JP)
KAIDO HIROSHI (JP)
Application Number:
PCT/JP2016/069241
Publication Date:
February 09, 2017
Filing Date:
June 29, 2016
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; C22C38/58; C21D1/18; C21D8/00
Domestic Patent References:
| WO2010134498A1 | 2010-11-25 |
Foreign References:
| JP2013249516A | 2013-12-12 | |||
| JP2005336595A | 2005-12-08 | |||
| JP2001279392A | 2001-10-10 | |||
| JP2012149317A | 2012-08-09 | |||
| JP2015081352A | 2015-04-27 |
Other References:
See also references of EP 3333276A4
Attorney, Agent or Firm:
UEBA, Hidetoshi et al. (JP)
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