HIGH-STRENGTH HOT-ROLLED STEEL SHEET EXCELLENT IN CORROSION RESISTANCE AND FATIGUE CHARACTERISTIC AT WELD ZONE

摘要

PURPOSE: To produce a high-strength hot-rolled steel sheet excellent in corrosion resistance and fatigue characteristic at the weld zone by applying a strain of specified elongation percentage to a steel sheet having specified contents of Cu, P, Nb and Mo. ;CONSTITUTION: A plastic strain of 1.0 to 10.0% of the elongation percentage is applied by skin-pass rolling, etc., to a hot-rolled steel sheet contg., by weight, 0.005-0.20% C, 0.005-1.0% Si, 0.1-2.5% Mn, 0.050-0.10% P, 0.001-0.010% S, 0.005-0.1% Al, 0.0005-0.0100% N, 0.10-0.50% Cu, 0.01-0.005% Nb, 0.1-0.50% Mo, 0.05-0.50% Ni and the balance Fe with inevitable impurities. The objective high-strength hot-rolled steel sheet excellent in corrosion resistance and with the softening of the weld heat-affected zone reduced is obtained in this way.;COPYRIGHT: (C)1993,JPO&Japio