摘要 |
PROBLEM TO BE SOLVED: To provide a high strength galvanized steel sheet and a high strength galvannealed steel sheet having excellent bulging formability and plating adhesion, and a production method therefor. SOLUTION: In the plated steel sheet, the surface of a steel sheet having a composition containing, by mass, 0.05 to 0.2% C, 0.2 to 2.0% Si, 0.2 to 2.5% Mn, 0.01 to l.5% Al and 0.003 to 1.0% Sn, and in which the relation between Si and Al satisfies 0.4(%)<=Si(%)+0.8Al(%)<=2.0(%), and, if required, containing at least one or more kinds selected from Ni, Cu, Co, Mo, Cr, V, Ti, Nb, B, rare earth metals, Ca, Zr and Mg in prescribed ranges, and the balance Fe with accompanying components and/or inevitable impurities, and in which the volume ratio of retained austenite is 2 to 20% is provided with a galvanized layer containing <=1% Al or a galvannealed layer containing 8 to 15% Fe and <=1% Al.
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