The difference between galvanized sheet and galvalume sheet is that the coating is different. The surface of the galvanized sheet is evenly distributed with a layer of zinc material, which acts as an anode protection for the base material.
The surface coating of aluminized zinc sheet is composed of 55% aluminum, 43.5% zinc and a small amount of other elements. At the microscopic level, the aluminized zinc coating appears as a honeycomb structure, and the "honeycomb" made of aluminum contains zinc. In this case, although the aluminum-zinc coating also plays the role of anode protection, on the one hand, due to the reduction of zinc content, on the other hand, because the zinc material is wrapped in aluminum and is not easy to electrolyze, the effect of anode protection is greatly reduced.