Hot-dip galvanizing, also known as hot-dip galvanizing, is a method in which steel components are immersed in molten zinc to obtain a metal coating. In recent years, with the rapid development of high-voltage power transmission, transportation, and communication, the protection requirements for steel parts have become higher and higher, and the demand for Hexagon Socket Head Bolt has also been increasing.

　　Hot-dip galvanized layer protection performance

　　The thickness of the electro-galvanized layer is usually 5-15μm, and the hot-dip galvanized layer is generally above 35μm, even as high as 200μm. Hot-dip galvanizing has good coverage, dense coating and no organic inclusions. As we all know, the anti-atmospheric corrosion mechanism of zinc includes mechanical protection and electrochemical protection. Under atmospheric corrosion conditions, there are protective films of ZnO, Zn(OH)2 and basic zinc carbonate on the surface of the zinc layer, which can slow down the corrosion of zinc to a certain extent. The layer protective film (also called white rust) is damaged and a new layer is formed. When the zinc layer is seriously damaged and the iron substrate is endangered, zinc will produce electrochemical protection to the substrate. The standard potential of zinc is -0.76V, and the standard potential of iron is -0.44V. When zinc and iron form a microbattery, zinc is dissolved as an anode. It is protected as a cathode. Obviously, the atmospheric corrosion resistance of hot-dip galvanizing to the base metal iron is better than that of electro-galvanizing.

　　 Hot-dip galvanizing process

The hot-dip galvanizing process of China Stud Supplier is a process of forming an iron-zinc alloy between the iron matrix and the outer pure zinc layer. The iron-zinc alloy layer is formed on the surface of the workpiece during hot-dip coating, which makes the iron and pure zinc layer There is a good combination between them, and the process can be simply described as: when the iron workpiece is immersed in the molten zinc, a solid solution of zinc and α iron (body core) is first formed on the interface. This is a crystal formed by dissolving zinc atoms in the base metal iron in a solid state. The two metal atoms are fused, and the attraction force between the atoms is relatively small. Therefore, when zinc reaches saturation in the solid solution, the two element atoms of zinc and iron diffuse each other, and the zinc atoms that have diffused (or infiltrated) into the iron matrix migrate in the matrix lattice, and gradually form alloys with iron, and diffuse The iron and zinc in the molten zinc form an intermetallic compound FeZn13, which sinks into the bottom of the hot-dip galvanizing pot, which is called zinc dross. When the workpiece is removed from the zinc immersion solution, a pure zinc layer is formed on the surface, which is a hexagonal crystal. Its iron content is not more than 0.003%.