Title:
LOW YIELD RATIO MARTENSITIC STAINLESS STEEL EXCELLENT IN CORROSION RESISTANCE AND PRODUCING METHOD THEREFOR
Document Type and Number:
Japanese Patent JP3503560
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide low yield ratio martensitic stainless steel excellent in corrosion resistance and suitable for an oil well pipe and a line pipe.
SOLUTION: (1) This low yield ratio martensitic stainless steel excellent in corrosion resistance has a composition containing ≤0.1% C, ≤1.0% Si, 0.2 to 1.5% Mn, 10.0 to 14.0% Cr, 1.5 to 7.0% Ni, 0.2 to 3.0% Mo, 0.001 to 0.1% Al and 0.001 to 0.1% N, simultaneously satisfying the following inequality (a), in which the volume fractional ratio of retained austenite in the structure is 4% or more, and has a yield ratio of 90% or less: Cr-16.6C≥9.6... (a). (2) In this producing method for low yield ratio martensitic stainless steel excellent in corrosion resistance, the martensitic stainless steel in the above (1) is subjected to heat treatment in the temperature range of >Ac1 point to <Ac3 as final heat treatment and is thereafter cooled to control its yield ratio to 90% or less.
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Inventors:
Keiichi Nakamura
Hideki Takabe
Kiyonobu Yoshimura
Hideki Takabe
Kiyonobu Yoshimura
Application Number:
JP2000035526A
Publication Date:
March 08, 2004
Filing Date:
February 14, 2000
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
C21D6/00; C22C38/00; C22C38/44; C22C38/50; (IPC1-7): C22C38/00; C21D6/00; C22C38/44; C22C38/50
Domestic Patent References:
| JP741909A | ||||
| JP101755A | ||||
| JP741857A | ||||
| JP2104639A |
Attorney, Agent or Firm:
Mikiji Sugioka (2 outside)