Highly corrosion resistant Zn-Al-Mg-Si alloy-plated steel material and process for its production

摘要

The present invention provides a Zn-Al-Mg-Si alloy-plated steel material with excellent corrosion resistance, characterized by comprising, in terms of wt%, Al: at least 45% and no greater than 70%, Mg: at least 1% and less than 5%, Si: at least 0.5% and less than 3%, with the remainder Zn and unavoidable impurities, wherein the Al/Zn ratio is 0.89-2.75 and the plating layer contains a scaly Mg 2 Si phase.