Galvanized steel pipe is the surface with hot-dip galvanized or electro-galvanized layer. Galvanized steel can increase corrosion resistance and prolong life. Galvanized steel pipe is widely used, except for water, gas, oil, generally low-pressure fluid line pipe, also used oil heater oil industry in particular, marine oil wells pipes, pipelines, chemical coking equipment, condensing coolers, washing coal distillate oil exchange used tubes, as well as the bridge piles, mine tunnel support frame with a pipe.
Galvanized steel pipe is divided into cold galvanized pipe and hot galvanized pipe, which is more extensive use of galvanized steel, hot galvanized steel is widely used in construction, machinery, mining, chemical, railway vehicles, the automotive industry, roads, bridges, container, sports facilities, agricultural machinery, petroleum machinery, prospecting machinery and other manufacturing industries. hot galvanized pipe is molten metal reacting with the iron matrix alloy layer, so that the substrate and coating combination of both. Galvanized pipe is first pickled, the steel surface in order to remove iron oxide, after pickling, cleaning tank by mixing an aqueous solution of ammonium chloride or zinc chloride and zinc chloride or ammonium chloride solution, and then into hot dip tank. Galvanized with coating uniformity, strong adhesion, long life and other advantages. Hot dip galvanized steel substrate with molten bath complicated physical, chemical reactions, the formation of corrosion-resistant zinc-iron alloy structure closely layer. Alloy layer and layer of pure zinc, steel base blend. Therefore it resistant to corrosion.
Chemical degreasing → washing → hot water hot water electrolysis degreasing → washing → washing → strong corrosive galvanized iron alloy → washing → washing → light → → washing → drying passivation
Galvanized means that the surface of the steel pipe has been galvanized, and it may be a welded pipe or a seamless pipe.
There are two types of galvanized seamless pipes (GI seamless pipe), hot-dip galvanizing (hot-dip galvanizing) and cold-dip galvanizing (electro-galvanizing). Hot-dip galvanizing has a thick galvanized layer, which has the advantages of uniform coating, strong adhesion, and long service life. However, the cost of electro-galvanizing is low, the surface is not very smooth, and its corrosion resistance is much worse than that of hot-dip galvanized pipes.