Title:
HIGH-STRENGTH STAINLESS STEEL SEAMLESS PIPE FOR OIL WELLS AND METHOD FOR MANUFACTURING SAME
Document Type and Number:
WIPO Patent Application WO/2023/053743
Kind Code:
A1
Abstract:
Provided are a high-strength stainless steel seamless pipe for oil wells, and a method for manufacturing same. This high-strength stainless steel seamless pipe for oil wells has a composition containing, in mass%, 0.002-0.05% of C, 0.05-0.50% of Si, 0.04-1.80% of Mn, 0.030% or less of P, 0.0020% or less of S, more than 14.0% and less than or equal to 17.0% of Cr, 4.0-8.0% of Ni, 1.5-3.0% of Mo, 0.005-0.10% of Al, 0.005-0.20% of V, 0.002-0.15% of N, 0.002-0.020% of Ti, and 0.006% or less of O, with the remainder comprising Fe and inevitable impurities, wherein Cr, Ni, Mo, Cu, C, Si, Mn and N satisfy a predetermined relational expression. The steel pipe has a microstructure in which the area percentage of a martensite phase is at least 70% and the average Ti concentration in inclusions having a major axis of at least 2 μm is at least 10 mass%, and has a yield strength of at least 758 MPa.
Inventors:
EGUCHI KENICHIRO (JP)
IDE SHINSUKE (JP)
IDE SHINSUKE (JP)
Application Number:
PCT/JP2022/030641
Publication Date:
April 06, 2023
Filing Date:
August 10, 2022
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C22C38/00; C21D8/10; C21D9/08; C22C38/58; C22C38/60
Domestic Patent References:
| WO2017168874A1 | 2017-10-05 | |||
| WO2021131445A1 | 2021-07-01 | |||
| WO2019225281A1 | 2019-11-28 | |||
| WO2020067247A1 | 2020-04-02 | |||
| WO2021200571A1 | 2021-10-07 |
Foreign References:
| JP2016145372A | 2016-08-12 |
Attorney, Agent or Firm:
KUMASAKA Akira et al. (JP)
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