| 摘要 |
PROBLEM TO BE SOLVED: To produce steel for a Cr-contg. oil well pipe excellent in hydrogen sulfide corrosion resistance and carbon dioxide gas corrosion resistance, and suitable for use in oil wells contg. hydrogen sulfide or carbon dioxide gas and severe in corrosive environments. SOLUTION: Steel contg. 0.08 to 0.30% C, 0.1 to 1.0% Si, 0.1 to 3.0% Mn, 1.0 to 9.0% Cr, 0.01 to 0.10% Al, 0.01 to 0.50% Ni and 0.0001 to 0.0020% B is subjected to hot forming, is thereafter rapidly cooled or slowly cooled to control the martensitic ratio to >=95% and is moreover tempered in the temp. range of <=Ac1 point, by which the steel for a Cr-contg. oil well pipe having >=552 MPa proof stress and excellent in hydrogen sulfide corrosion resistance and carbon dioxide gas corrosion resistance can be obtd.
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