Aluminized steel plate is coated with a layer of pure aluminum or aluminum-silicon alloy steel plate containing 5%-10% silicon on the surface of carbon steel. The methods of aluminum plating include hot plating, electrophoresis, and vacuum evaporation. Among them, the hot plating is the most widely used. Aluminized steel sheet has good high temperature oxidation resistance, does not change color for a long time at 450℃, and the maximum use temperature can reach 750℃. It also has good atmospheric corrosion resistance, especially against SO2, H2S, CO2 and other gases. The corrosion resistance is 3 to 6 times that of galvanized steel, which is mainly used in automobile exhaust systems, heat-resistant appliances, beverage cans, etc. Aluminum plate has the following 5 characteristics:
1. High temperature resistance: due to the specific combination of steel plate base material and coating structure, a kind of iron-aluminum alloy is formed, so that the aluminum plate has excellent high temperature resistance. At 450°C, extremely high reflectivity can be guaranteed. Above 480°C, the appearance of the coating becomes gray. When the temperature is as high as 650°C, the protective layer to prevent oxidation of the steel plate is still well preserved, and no peeling is seen.
2. Heat reflectivity: at a high temperature of 480 degrees Celsius, the aluminum plate can reflect 80% of the incoming heat. Therefore, the aluminized plate can be made into an efficient heat insulation barrier or a heat reflector in high temperature applications, and the temperature in the furnace can be rapidly increased through effective heat reflection.
3. Mechanical strength: At room temperature, the mechanical strength of the aluminized plate is consistent with that of its base material. At the same high temperature of 480℃, the strength of aluminized steel plate is 10 times that of aluminum plate, so the thickness of steel plate can be reduced by at least 30%.
4. Corrosion resistance: During the hot-dip coating process, the molten aluminum immediately reacts with oxygen in the air to form a protective layer of Al2O3, which immediately passivates the surface of the steel plate. This protective layer is very stable and insoluble in water. Even if the surface of the steel plate is scratched later, this protective layer has a self-healing function. Therefore, the aluminized plate has strong corrosion resistance to chemical corrosion.
5. Ecological characteristics: The non-chemically passivated aluminum plate has no effect on health, so it can be used for food processing. The test reports of many professional organizations confirm that it is an environmentally friendly product that is harmless to the human body. The aluminum plate can be fully recycled. Aluminum plate can be comparable to stainless steel but the price is only about one-third of stainless steel.
