Hot dip galvanized pipes are galvanized on general steel pipes to improve their corrosion resistance. Hot dip galvanized pipes are formed by reacting molten metal with an iron substrate to form an alloy layer, which combines the substrate and coating. Hot dip galvanized pipes will first be acid washed to remove the iron oxide on the surface of the steel pipe. After acid washing, ammonium chloride or zinc chloride aqueous solution or a mixture of ammonium chloride and zinc chloride aqueous solution will be used for secondary cleaning, and then sent to the hot-dip plating tank. Hot dip galvanizing has advantages such as uniform coating, strong adhesion, and long service life. The hot-dip galvanized steel pipe substrate undergoes complex physical and chemical reactions with the molten plating solution to produce a corrosion-resistant and dense zinc iron alloy layer. The alloy layer is integrated with the pure zinc layer and the steel pipe substrate, and has extremely strong corrosion resistance. Purpose: 1 Hot dip galvanized steel pipes have been widely used in the construction industry, mainly for making building frames, brackets, ceilings, etc. Hot dip galvanized steel pipes have good corrosion resistance and can maintain a long service life even in humid outdoor environments. Meanwhile, hot-dip galvanized steel pipes have high strength and can withstand significant pressure, making them widely used in construction projects. 2. Hot dip galvanized steel pipes also play an important role in the petroleum industry, mainly used for transporting various liquids and gases such as oil and natural gas. In the process of oil transportation, high requirements are placed on the corrosion resistance and sealing of pipelines, and hot-dip galvanized steel pipes can well meet these requirements. In addition, hot-dip galvanized steel pipes also have good insulation performance, which can reduce energy loss. 3. Hot dip galvanized steel pipes are widely used in the chemical industry, especially in the fields of pharmaceuticals, coatings, dyes, etc. The chemical industry has high requirements for the corrosion resistance of pipeline materials, and hot-dip galvanized steel pipes have good corrosion resistance, which can effectively protect pipelines and extend their service life. At the same time, the inner wall of hot-dip galvanized steel pipes is smooth and has less resistance to fluid transport, which is beneficial for improving production efficiency. 4. Urban railway and urban rail transit are important modes of transportation in modern cities, and hot-dip galvanized steel pipes play a connecting and supporting role in urban rail transit. The track bracket made of hot-dip galvanized steel pipe has the advantages of strong bearing capacity, good stability, and long service life, and is suitable for various urban rail transit facilities. 5. Hot dip galvanized steel pipes are widely used in agricultural fields such as irrigation and animal husbandry. Hot dip galvanized steel pipes can withstand the humid environment in farmland, are not easy to rust, and can be used for a long time. Meanwhile, hot-dip galvanized steel pipes have the characteristic of strong load-bearing capacity and are suitable for the construction of some agricultural facilities, such as breeding racks in farms and support frames in nurseries.