Steel pipe knowledge: The difference between cold galvanized pipe and hot galvanized pipe

51 steel pipe network () to provide, steel knowledge: the difference between cold galvanized pipe and hot-dip galvanized pipe Hot galvanized pipe is to make molten metal and iron matrix reaction to produce alloy layer, so that the substrate and the coating are combined. 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.
Cold galvanizing is electro-galvanizing, galvanizing is rare, only galvanized in the outer tube wall (hot-plated --- both inside and outside plating), only 10-50g/m2, its own corrosion resistance is much worse than hot galvanized tube . Regular galvanized pipe manufacturers, in order to ensure quality, mostly do not use electroplating zinc (cold plating). Only those small businesses with small scale and outdated equipment use electro-galvanizing, and of course their prices are relatively cheap. The Ministry of Construction has formally announced that cold galvanized pipes that are outdated in technology are not allowed to use cold galvanized pipes as water and gas pipes.
The galvanized steel pipes that are generally used today are hot-dip galvanized, and the electrical lines used are cold galvanized, and the colors are somewhat different.