HIGH STRENGTH STEEL SHEET EXCELLENT IN FORMABILITY AND WELDABILITY AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To provide steel components and annealing conditions as to a high strength steel sheet and a hot dip galvanized steel sheet excellent in formability and weldability and used for automotive parts or the like.;SOLUTION: This high strength steel sheet and hot dip galvanized steel sheet excellent in formability and weldability contain, by weight, 0.02 to 0.15% C, 0.01 to 0.1% Si, 1.0 to 2.8% Mn, ≤0.02% P, ≤0.02% S and 0.07 to 0.7% Al, contain, at need, 0.0005 to 0.01% Ca and 0.005 to 0.005% rare earth metals, contain, at need, one or ≥ two kinds among ≤0.5% Cr, ≤0.5% Ni, ≤0.5% Cu, ≤0.5% Mo and ≤0.1% V, and the balance Fe with inevitable impurities and have metallic structures of ferrite and martensite including retained austenite.;COPYRIGHT: (C)2000,JPO