ALUMINIUMALLOY COATED STEEL MATERIAL AND METHOD FOR MANUFACTURING THE SAME

摘要

An object of the present invention is to provide an aluminum or aluminum alloy-coated steel material having better corrosion resistance than the conventional aluminum or aluminum alloy-coated steel material, together with a manufacturing method thereof. Specifically, the present invention provides an aluminum or aluminum alloy-coated steel material, comprising: base steel; and a coating layer formed on a surface of the base steel and containing by mass % Mg: 6% to 10%, Si: 3% to 7%, Fe: 0.2% to 2%, Mn: 0.02% to 2%, and the balance as Al and incidental impurities, wherein the coating layer has ±Al-Mg 2 Si-(Al-Fe-Si-Mn) pseudoternary eutectic microstructure and area ratio of the microstructure in the coating layer is at least 30%.