Hot-dip galvanizing is the reaction of the molten metal with the iron matrix to produce an alloy layer, so that both the substrate and the coating are combined. The hot-dip galvanizing pipe is made by pickling the steel pipe to remove the iron oxide on the surface of the steel pipe. After pickling, it is washed by ammonium chloride or zinc chloride aqueous solution or ammonium chloride and zinc chloride mixed aqueous solution tank, And then into the hot dip bath.

Hot-dip galvanized steel pipe is a steel pipe matrix and molten bath complex physical and chemical reactions, the formation of corrosion-resistant structure of the zinc-iron alloy layer. Alloy layer and pure zinc layer, steel pipe body integration, so hot-dip galvanized steel pipe with uniform coating, strong adhesion, long life and other advantages.