STEEL FOR CRUDE OIL TANK HAVING EXCELLENT CORROSION RESISTANCE, WELDED JOINT, AND CRUDE OIL TANK

摘要

PROBLEM TO BE SOLVED: To provide a steel for a crude oil tank capable of reducing greatly overall corrosion or local corrosion generated in the crude oil tank, and to provide a welded joint and the crude oil tank.;SOLUTION: When manufacturing a crude oil tank by welding a steel containing in mass%, 0.03-0.16% C, 0.05-1.50% Si, 0.1-2.0% Mn, ≤0.025% P, ≤0.010% S, 0.005-0.10% Al, ≤0.008% N, 0.0001-0.01% Sc and 0.03-0.4% Cu, and also containing one or two or more kinds selected from 0.01-1.0% W, 0.01-0.5% Mo, 0.005-0.2% Sn and 0.005-0.4% Sb, a welded joint is formed, in which a welded metal part satisfies following relations: 1(Cu content in a welded metal/Cu content in a base metal)≤50, and 0.25≤(Cu content in the welded metal/total content of Mo and W in the welded metal)≤3.;COPYRIGHT: (C)2012,JPO&INPIT