HOT DIP ZN-AL-MG ALLOY PLATED STEEL SHEET HAVING EXCELLENT CORROSION RESISTANCE AND METHOD FOR MANUFACTURING THE SAME

摘要

The present invention relates to a zinc-aluminum-magnesium alloy plated steel sheet with excellent corrosion resistance, and a method to manufacture the same. Provided is the method to manufacture the zinc-aluminum-magnesium alloy plated steel sheet with excellent corrosion resistance comprising: a shot blasting step of applying compressive residual stress of -100 to -400 MPa to a hot rolled steel sheet after treatment while hot rolled scale is removed by shot blasting the hot rolled steel sheet; and a plating step of zinc-aluminum-magnesium plating by submerging the hot rolled steel sheet in a zinc-aluminum-magnesium alloy plating bath. Moreover, comprised are a steel sheet and a zinc-aluminum-magnesium alloy plating layer on the steel sheet, and a corrosion product of Zn_6Al_2(CO_3)(OH)_164H_2O is generated near an interface of the plating layer under corrosive conditions. Therefore, provided is the zinc-aluminum-magnesium alloy plated steel sheet with excellent corrosion resistance.