Hot dip galvanized steel sheet having high strength and high ductility and excellent in adhesive strength of plating

PURPOSE: To improve the adhesive strength of plating without deteriorating the superior balance between strength and ductility, which is the feature of a complex structure steel sheet containing residual austenite, by specifying respective contents of C, Mn, Si, Al, etc., in the composition of a steel sheet. CONSTITUTION: The steel sheet for hot dipping has a composition consisting of, by weight, 0.05-0.30% C, ≤0.5% Si, 0.8-3.0% Mn, ≤0.02% P, ≤0.01% S, 0.5-1.5% Al, ≤0.008% N, and the balance Fe with inevitable impurities and further containing, as necessary, one or ≥2 kinds selected from 0.005-0.05% Ti, 0.005-0.05% Nb, 0.0005-0.003% B, 0.2-1.0% Cu, 0.2-1.0% Ni, 0.2-1.0% Cr, and 0.2-1.0% Mo. A cold rolled steel sheet of this composition, passes through a continuous hot dip galvanizing line and subjected to annealing and to the formation of a galvanized layer. COPYRIGHT: (C)1993,JPO&Japio