Hot-dip galvanizing tubes react molten metal with an iron matrix to produce an alloy layer, thereby combining the matrix and the plating. Hot-dip galvanizing is performed by first pickling the steel pipe. In order to remove the iron oxide on the surface of the steel pipe, after pickling, cleaning is performed by an aqueous solution of ammonium chloride or zinc chloride or an aqueous solution of ammonium chloride and zinc chloride, and then fed. Hot dip plating tank. Hot-dip galvanizing has the advantages of uniform coating, strong adhesion and long service life. The galvanized steel pipe substrate and the molten plating solution undergo complex physical and chemical reactions to form a corrosion-resistant and compact zinc-iron alloy layer. The alloy layer is integrated with the pure zinc layer and the steel pipe base body. Therefore, its corrosion resistance is strong. Source of information: http://