It is superior in fatigue property of the basic material and compactibility after the welding and the high intensity cold rolling steel sheet and the high intensity finishing steel sheet null where the welding thermal effect section is difficult

摘要

PROBLEM TO BE SOLVED: To provide a high strength steel sheet in which the fatigue characteristics of a base material and press formability after welding are made better, and the reduction of strength in the welding heat affected zone can be suppressed. ;SOLUTION: This steel sheet is the one contg., by weight, 0.01 to 0.15% C, 0.005 to 1.0% Si, 0.1 to 2.2% Mn, 0.001 to 0.05% P, 0.001 to 0.01% S, 0.0005 to 0.01% N, 0.001 to 0.10% Al, 0.001 to 0.02% Ti, 0.005 to 0.05% Nb, 0.05 to 0.5% Mo, 0.2 to 2.0% Cu, 0.05 to 2.0% Ni and Fe as the main component and also satisfying the inequality of 0.22≥C(%)+(Si/30)(%)+(Mn/20)(%)+(Mo/15)(%).;COPYRIGHT: (C)2000,JPO