The main differences between galvanized and zinc-plated are their composition, corrosion resistance, heat resistance, weight, and application scenarios.
Composition and structure Galvanized sheet: The surface is coated with a layer of zinc, and the zinc content is usually between 1.5% and 3.5%, which mainly plays an electrochemical protection role.
Galvanized sheet: The surface coating is composed of 55% aluminum, 43.5% zinc, and a small amount of other elements to form a honeycomb structure. The combination of aluminum and zinc provides a dual protective effect.
Corrosion resistance Galvanized sheet: It mainly protects the substrate from corrosion through the sacrificial anode effect of zinc. In a humid environment, the zinc layer may be accelerated by electrolysis. If exposed to harsh environments for a long time, the anti-corrosion effect will gradually weaken.
Galvanized sheet: The combination of aluminum and zinc provides better corrosion resistance, especially in high temperature and high humidity environments. Aluminum has strong antioxidant properties, and zinc provides electrochemical protection. The dual role makes the corrosion resistance of galvanized sheet better than that of galvanized sheet.
Heat resistance
Galvanized sheet: The heat resistance is relatively poor, and the coating is easy to deteriorate and fall off in high temperature environment.
Alu-zinc sheet: Due to the aluminum component, it has better heat resistance and can remain stable in high temperature environment above 300°C.
Weight
Galvanized sheet: The density of zinc is relatively high (7.14 g/cm3), so the weight of galvanized sheet is relatively heavy.
Alu-zinc sheet: The coating density is between aluminum and zinc (about 5.3 g/cm3), so the weight of galvanized sheet is relatively light.
Application scenario
Galvanized sheet: It is widely used in construction, automobile, home appliances and other industries, especially in occasions with low anti-corrosion requirements.