With the continuous development at the national level, the improvement of people's living standards, and the acceleration of industrialization. Galvanized sheet has been applied in many fields. The advantage of galvanizing is that it has a long corrosion life. Galvanized sheet prevent corrosion on the surface of the steel sheet and prolong their service life. The surface of the steel plate is coated with a layer of metallic zinc, which is called galvanized sheet. Galvanized sheet products are generally widely used in construction, electronics, agriculture, animal husbandry and fishery, light industry, automobile, home appliances, commodity packaging and other industries.

In the surface treatment process of galvanized sheet, due to the different treatment methods in the coating process, the surface state will be different, such as flat spangle, ordinary spangle, non-spangle, fine spangle and phosphating surface. The galvanized sheet should have a good appearance in use, and there should be no defects harmful to the use of the product, such as holes, scum, chemical plating, cracks, wear, white rust, chromate scale, excessive thickness of the coating, etc. Foreign standards are not very clear about specific appearance defects.

Due to the strong activity of aluminum, the diffusion bonding between liquid aluminum and solid iron is very strong, so the composite layer is thick and difficult to control. This will affect its processing performance, and it will easily cause the coating to crack or even fall off during the deep drawing process. The corrosion resistance of the aluminum coating is fully reflected without scratches. On the one hand, because a dense protective film can be formed on the surface of aluminum, it will not be further corroded under very harsh conditions, so its anti-corrosion effect is very strong.

Galvanized sheet has strong corrosion resistance. The reason why we have to do a good job of surface treatment is to prevent the surface of the steel plate from being corroded. Due to its strong corrosiveness, it will have a great impact on the service life of the product. Therefore, after the surface is coated with a layer of metallic zinc, the service life of the product can be longer. It can play a very good role in safety protection. After the galvanized sheet is treated, it can indeed play a very good role in safety protection. We know that the surface is coated with a layer of metal zinc. It does have many characteristics in the actual use process, which can avoid surface damage and play a better role in safety. 

However, during the production process of galvanized sheets, surface quality defects such as discoloration, black lines, black spots, and scratches often appear on the surface, which not only reduces the quality of galvanized sheet products, but also restricts market promotion. Therefore, controlling and improving the surface quality of galvanized sheets is a comprehensive project. The quality control of galvanized sheet involves many aspects such as production process, equipment level, production environment and personnel quality. Only by closely cooperating with all aspects and links and eliminating various unfavorable factors can better product surface quality be obtained.