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Hot dip galvanizing, also known as hot dip galvanizing and hot dip galvanizing, is an effective method of metal corrosion prevention, mainly used for metal structures and facilities in various industries. It is to immerse the derusted steel parts in molten zinc at about 500 ℃ to adhere a zinc layer to the surface of the steel components, thereby achieving the purpose of corrosion prevention. Hot dip galvanizing process flow: finished product pickling – water washing – adding auxiliary plating solution – drying – hanging plating – cooling – medicating – cleaning – polishing – completion of hot dip galvanizing 1. Hot dip galvanizing is developed from the older hot dip galvanizing method, and has a history of more than 170 years since France applied hot dip galvanizing to industry in 1836. In the past thirty years, with the rapid development of cold rolled strip steel, the hot dip galvanizing industry has developed on a large scale.
Hot dip galvanizing, also known as hot dip galvanizing, is a method for obtaining a metal coating on steel components by immersing them in molten zinc. With the rapid development of high-voltage power transmission, transportation, and communications, the requirements for the protection of steel parts are increasingly high, and the demand for hot dip galvanizing is also increasing.

Protective performance
Generally, the thickness of the galvanized layer is 5~15 μ m. The hot-dip galvanized layer is generally at 35 μ Above m, even up to 200 μ m。 Hot dip galvanizing has good covering ability, dense coating, and no organic inclusions. It is well known that the mechanisms of zinc’s resistance to atmospheric corrosion include mechanical protection and electrochemical protection. Under atmospheric corrosion conditions, the surface of the zinc layer has ZnO, Zn (OH) 2, and basic zinc carbonate protective films, which to some extent slow down the corrosion of zinc. If this protective film (also known as white rust) is damaged, it will form a new film layer. When the zinc layer is severely damaged and endangers the iron substrate, zinc provides 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 micro battery, zinc is dissolved as the anode, and iron is protected as the cathode. Obviously, the atmospheric corrosion resistance of hot dip galvanizing on the base metal iron is better than that of electrogalvanizing.
Zinc coating formation process
The formation process of the hot dip galvanized layer is a process of forming an iron zinc alloy between the iron substrate and the pure zinc layer outside of Z. The iron zinc alloy layer is formed on the surface of the workpiece during hot dip plating, which allows for a good combination between the iron and the pure zinc layer. The process can be simply described as follows: When the iron workpiece is immersed in the molten zinc liquid, zinc and zinc are first formed on the interface α Iron (body core) solid melt. This is a crystal formed by dissolving zinc atoms in the solid state of the base metal iron. The two metal atoms are fused, and the attraction between the atoms is relatively small. Therefore, when zinc reaches saturation in the solid melt, the two elemental atoms of zinc and iron diffuse with each other, and the zinc atoms diffused into (or infiltrated into) the iron matrix migrate in the matrix lattice, gradually forming an alloy with iron, while the iron and zinc diffused into the molten zinc liquid by high-strength steel form an intermetallic compound FeZn13, which sinks into the bottom of the hot galvanizing pot, forming zinc slag. When the workpiece is removed from the zinc dipping solution, a pure zinc layer is formed on the surface, which is hexagonal crystal. Its iron content is not greater than 0.003%.
Technical differences
The corrosion resistance of hot galvanizing is much higher than that of cold galvanizing (also known as galvanization). Hot galvanizing will not rust in a few years, while cold galvanizing will rust in three months.
The electrogalvanizing process is used to protect metals from corrosion. “There will be a good metal protective layer on the edges and surfaces of the product, which adds a beautiful part to the practicality. Nowadays, major enterprises have increasingly high requirements for product parts and technology, so it is necessary to reform the technology at this stage.”