Hot Dipped Cold Rolled Aluminium Zinc Coated Steel / Alu-Zinc Galvalume / Galvanized Steel Sheet

Plating aluminum plate

Aluminized steel plate is a steel plate with a layer of pure aluminum or aluminum-silicon alloy containing 5%-10% silicon on the surface of the plate. Compared with galvanized sheet, aluminum plate has the biggest advantage of thermal radiation reflection and high temperature oxidation resistance, and has good corrosion resistance in the environment of thermal radiation, acid, condensate and atmospheric corrosion. From the observation of past performance, the outdoor service life of aluminum plate is 2-5 times longer than galvanized steel plate, and it is particularly suitable for the corrosion of SO2 and H2S, so it is widely used in the manufacture of automobile mufflers, exhaust pipes, fuel tanks; Furnace, heat exchanger, dryer, water heater, cooker and other steel products under high temperature operating environment.

Compared with aluminized plate, zinc-coated plate has the advantage of thin coating and simple process, so its cost is lower. In addition, the solderability, notch protection and cathodic protection of aluminum plate are poor, so in the case of high temperature and acid corrosion resistance requirements are low, businesses are still willing to choose galvanized plate (or zinc aluminum alloy plate).
Pure zinc plated plate

Ordinary galvanized sheet (pure zinc coating board) is divided into electroplating (cold plating) and hot dip galvanizing (hot plating) according to the coating method. Electrogalvanizing is a processing method that uses electrolysis equipment to put the plate into the solution of zinc salt, and uses the current to move from the positive pole to the negative pole, so that zinc forms a sedimentary layer on the plate. This method uses a chemical method to attach zinc ions to the surface of the steel. The zinc layer is usually thin, and the oxidation resistance is relatively poor. Cold galvanized surface is smooth, bright, uniform, relatively beautiful. Cold plating method is flexible to use, can only be in the specified part of the formation of coating.

Hot-dip galvanizing involves dipping the sheet into molten zinc solution and removing the sheet after forming an iron-zinc alloy layer. Hot dip galvanizing has good covering ability, fine coating, no inclusion of organic matter, tight combination between iron and pure zinc layer, strong adhesion is not easy to fall off, and better oxidation prevention effect. Due to the good ductility of metal zinc, its alloy layer is firmly attached to the steel matrix, so hot dip galvanized can be cold punching, rolling, bending and other forming processes, without damage to the coating. However, compared with cold galvanizing, the appearance of hot dip galvanizing is darker, the thickness is even and slightly rough, and it is easy to produce process water lines and droplet nodules in the processing process. Hot plating method is immersion processing, only on the plate plating.

Generally speaking, hot dip galvanizing is charged according to the thickness of the coating, and cold plating is mostly charged according to the surface area of the substrate. Hot dip galvanized due to the use of more metal zinc (more than 10 times more than cold galvanized), the cost is higher than electroplating; However, the pollutant emission of electroplating is far more than that of hot plating.