Patent ID: 7267890
Filing Date: 2007-09-11
Classification: C23C,Y10S,Y10T

Abstract:
1. A high-strength hot-dip galvanized steel sheet having high plating adhesion after severe deformation and ductility, the hot-dip galvanized steel sheet having a plated layer containing, in mass, Al: 0.001 to 0.5%, and Mn: 0.001 to 2%, with the balance being of Zn and unavoidable impurities, on the surface of a steel sheet consisting essentially of, in mass, C: 0.0001 to 0.3%, Si: 0.01 to 2.5%, Mn: 0.01 to 3%, Al: 0.31 to 4%, and the balance being Fe and unavoidable impurities, characterized in that: Si content: X (in mass %), Mn content: Y (in mass %) and Al content: Z (in mass %) in the steel, and Al content: A (in mass %) and Mn content: B (in mass %) in the plated layer satisfy the following equation 1; and the microstructure of the steel sheet has the main phase comprising ferrite at 70 to 97% in volume and the average grain size of the main phase being not more than 20 μm, and a second phase comprising one or more austenite and martensite at 3 to 30% in volume and the average grain size of the second phase being not more than 10 μm: