| 摘要 |
PROBLEM TO BE SOLVED: To produce steel for an oil well having excellent SSC resistance and >=110 ksi YS and to provide a method for inexpensively producing it. SOLUTION: This steel for an oil well is composed of low alloy steel contg., by weight, 0.2 to 0.35% C, 0.2 to 0.7% Cr, 0.1 to 0.5% Mo and 0.1 to 0.3% V, in which the total of precipitated carbides is 2 to 5 wt.%, and, among which, the ratio of MC type carbides is 8 to 40 wt.%, and, this steel for an oil yell is producible by subjecting the steel having the above chemical compsn. only to quenching from the temp. equal to or above the A3 transformation point and tempering at >=650 deg.C to the temp. equal to or below the Ac1 transformation point.
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