Patent ID: 8389128

Claim:
A high tensile-strength galvanized steel sheet, comprising: as a percentage of mass, C: at least 0.05% but less than 0.12%, Si: at least 0.01% but less than 0.35%, Mn: 2.0% to 3.5%, P: 0.001% to 0.020%, S: 0.0001% to 0.0030%, Al: 0.005% to 0.1%, N: 0.0001% to 0.0060%, Cr: more than 0.5% but not more than 2.0%, Mo: 0.01% to 0.50%, Ti: 0.010% to 0.080%, Nb: 0.010% to 0.080%, and B: 0.0001% to 0.0030%, the remainder being Fe and unavoidable impurities, having a microstructure that contains 20% to 70% by volume ferrite having an average grain size of 3.5 μm or less, a tensile strength of at least 980 MPa, tensile strength (TS) x elongation (El) of at least 15000 MPa·%, tensile strength (TS)×hole expansion ratio (λ) of at least 43000 MPa·% and a critical bending radius of not more than 1.5×sheet thickness (t) of the steel sheet, and a galvanized zinc layer at a coating weight in a range of 20 to 150 g/m 2 per side on a surface thereof.