Hot dipped galvanized steel pipe is the molten matrix metal and iron alloy layer generated reaction, so that the substrate and coating combination of both. Hot dippped galvanized steel pipe is first pickled, the steel surface in order to remove iron oxide, after pickling, cleaning by a mixed aqueous solution of ammonium chloride bath or an aqueous solution of zinc chloride or ammonium chloride and zinc chloride, and then into hot dip tank. 

Hot dipped galvanized steel pipe has galvanized coating uniformity, strong adhesion, long life and other advantages. Hot dip galvanized steel pipe substrate with the molten bath complicated physical, chemical reaction, the formation of corrosion- resistant compact structure of zinc-iron alloy layers. Alloy layer and the pure zinc layer, integrated steel substrate. So its resistant to corrosion.