Galvanized steel pipe cold galvanized pipe, hot-dip tube, the former has been disabled, the latter has also been the country to promote the temporary use. Hot-dip galvanized pipe Hot-dip galvanized pipe is the molten metal and the reaction of the iron matrix alloy layer, which So that both the substrate and the coating combination. Hot-dip galvanizing is the first pickling of the steel pipe, in order to remove iron oxide on the surface of the steel pipe, pickling, washing with ammonium chloride or zinc chloride aqueous solution or ammonium chloride and zinc chloride mixed aqueous solution tank, and then feeding Hot dipping tank. Hot dip galvanized coating with uniform, strong adhesion, long life and other advantages.
Hot-dip galvanized steel pipe: The steel pipe matrix and the molten bath complex physical and chemical reactions, the formation of corrosion-resistant zinc-iron alloy layer closely. Alloy layer and pure zinc layer, steel substrate integration. Therefore, its strong corrosion resistance.
Cold galvanized steel cold galvanized steel is galvanized, zinc content is very small, only 10-50g / m2, its own corrosion resistance is much different from the hot-dip galvanized pipe. Formal galvanized pipe manufacturer, in order to ensure the quality, most do not use electro-galvanized (cold plating). Only small-scale, outdated small businesses use electro-galvanized, and of course their prices are relatively cheaper. Currently the Ministry of Construction has officially below, out of cold-galvanized pipe technology behind, not allowed to use cold galvanized pipe for water, gas pipe.
Cold galvanized steel pipe: zinc layer is electroplating layer, zinc layer and steel substrate independent stratification. Thin zinc layer, zinc layer simply attached to the steel substrate, easy to fall off. Therefore, its corrosion resistance is poor. In new residential construction, the use of cold galvanized steel pipe as a water supply pipe is forbidden.