HOT DIP ALLOY COATED STEEL SHEET HAVING EXCELLENT CORROSION RESISTANCE, HIGH FORMABILITY AND GOOD APPEARANCE AND METHOD FOR PRODUCTION THEREOF

摘要

The present invention relates to a Zn-Mg-Al-based alloy plating steel sheet with improved surface quality, corrosion resistance, and excellent workability; and a method for manufacturing the same. According to an embodiment of the present invention, provided are the alloy plating steel sheet having a plating layer in the surface of the steel sheet, and the method for manufacturing the same. In the plating layer, a primary crystal MgZn_2 phase in the form of an isometric polygon or a rod of 10-30 vol% in terms of phase fraction exists inside a ternary eutectic structure (Zn/Al/MgZn_2) by cooling molten plating bath comprising more than 10 wt% and 15 wt% or less of Al, 2 wt% or more and less than 5 wt% of Mg, and residues including Zn and unavoidable impurities.