ELECTRIC RESISTANCE WELDED (ERW) STEEL PIPE FOR OIL WELL USE AND PROCESS FOR PRODUCING ERW STEEL PIPE FOR OIL WELL USE

摘要

Provided are: an ERW steel pipe for oil well use which can achieve a strength corresponding to API SPEC 5CT Grade P110 without undergoing overall heat treatment and which exhibits excellent toughness; and a process for producing an ERW steel pipe for oil well use. This ERW steel pipe for oil well use has a composition which contains, in mass%, 0.05 to 0.12% of C, 0.03 to 0.5% of Si, 0.80 to 2.2% of Mn, up to 0.03% of P, up to 0.003% of S, up to 0.08% of Al, 0.01 to 0.1% of Nb, 0.005 to 0.03% of Ti, and 0.0005 to 0.003% of B, and up to 0.008% of N, and satisfies Ti3.4N, with the balance being Fe and unavoidable impurities, and which has a V_C90 of 15 to 40.