Title:
MARTENSITE-BASED STAINLESS STEEL MATERIAL
Document Type and Number:
WIPO Patent Application WO/2022/075405
Kind Code:
A1
Abstract:
Provided is a martensite-based stainless steel material which exhibits high strength and excellent SSC resistance. This martensite-based stainless steel material contains, in terms of mass%, not more than 0.030% of C, 5.05-7.50% of Ni, 10.00-14.00% of Cr and 1.50-3.50% of Mo and has a yield strength of not less than 758 MPa. On two 1000 µm lines LS extending in the wall thickness direction, which are centered at any two points at a depth of 2 mm from the inner surface, the degree of segregation ΔCr of Cr as defined by formula (1) and the degree of segregation ΔMo of Mo as defined by formula (2) satisfy formula (3). Formula (1): ΔCr=([Cr*]max-[Cr*]min)/[Cr*]ave
Formula (2): ΔMo=([Mo*]max-[Mo*]min)/[Mo*]ave
Formula (3): ΔCr+ΔMo ≤ 0.59
Inventors:
MATSUO DAISUKE (JP)
TOMIO YUSAKU (JP)
TOMIO YUSAKU (JP)
Application Number:
PCT/JP2021/037134
Publication Date:
April 14, 2022
Filing Date:
October 07, 2021
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
C21D8/06; C21D8/10; C21D9/00; C21D9/08; C22C38/00; C22C38/54
Domestic Patent References:
| WO2020095559A1 | 2020-05-14 | |||
| WO2019225281A1 | 2019-11-28 | |||
| WO2019225280A1 | 2019-11-28 | |||
| WO2019065116A1 | 2019-04-04 |
Other References:
See also references of EP 4227424A4
Attorney, Agent or Firm:
ASCEND IP LAW FIRM (JP)
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