Difference between galvanized steel coil and aluminized zinc steel coil
Compared with aluminum zinc alloy, zinc coating has relatively active chemical properties, so its corrosion resistance is greatly different. The test under the same outdoor conditions shows that the service life of aluminum zinc plated sheet is more than four times that of zinc plated sheet.
The aluminum zinc alloy structure of the aluminum zinc plated steel plate is composed of 55% aluminum, 43.4% zinc and 1.6% silicon solidified at 600 ℃. The whole structure is composed of aluminum iron silicon zinc, forming a dense quaternary crystal, thus forming a strong and effective barrier to prevent the penetration of corrosion factors.
Characteristics of aluminum zinc plated steel plate:
The corrosion resistance of "55% aluminum zinc plated steel coil" comes from the barrier layer protection function of aluminum and the sacrificial protection function of zinc. When zinc is sacrificed to protect the cut edges, scratches and coating scratches, aluminum will form an insoluble oxide layer to play a barrier protection role. The aluminum zinc plated alloy steel coil has been exposed to various atmospheric environments for more than 20 years. It has been proved that the cutting protection function of 55% aluminum zinc plated steel plate is better than that of galvanized steel plate and 5% aluminum zinc plated steel plate.
The heat resistance of 55% Al Zn alloy plated steel sheet is better than that of galvanized steel sheet, and is similar to that of aluminized steel sheet in high temperature oxidation resistance. Aluminum zinc alloy steel plate can be used in high temperature environment up to 315 ℃.
The 55% Al Zn alloy plated steel plate has high reflectivity, making it a heat resistant barrier; The thermal reflectivity of the aluminum zinc plated steel plate is almost twice that of the zinc plated steel plate. Therefore, it can also achieve energy-saving effect when acting as a roof and panel without painting.
Due to the excellent adhesion between the zinc layer and the paint of the aluminum zinc plated steel plate, when used as a sign board for general purposes, it can be painted without pre-treatment and weathering treatment; The galvanized steel plate needs weathering treatment and pretreatment.
Use of aluminum zinc plated steel plate:
According to different thickness specifications, the main uses of aluminum zinc plated steel plate are: power distribution cabinet (1.2-2mm thick); Solar water heater (0.32mm); Anti theft door panel; Home appliance backplane;
Hot galvanizing is generally used for steel strip or steel wire (strand). The steel surface is covered with zinc layer to prevent the corrosion of the atmosphere, so as to prevent the continuous corrosion of the substrate and ensure the service life of the substrate. Moreover, zinc is more active than iron, and can also sacrifice zinc layer to protect steel substrate in case of corrosion.
Aluminum zinc plating has stronger protective effect and better corrosion resistance than zinc plating products. The whole structure consists of aluminum iron silicon zinc, forming a dense quaternary crystal, which forms a barrier on the steel plate, thus effectively preventing the penetration of corrosion factors. Corrosion resistance comes from the barrier layer protection function of aluminum and the sacrificial protection function of zinc. When zinc is sacrificed to protect the cut edges, scratches and scratched parts of the coating, aluminum will form an insoluble oxide layer to play the role of barrier protection.