Dip the sheet into the molten zinc bath to make a layer of zinc sheet stick to the surface. The main use of continuous galvanized process production, that is, into a roll of steel continuous immersion in the melting of zinc plating tank to make galvanized steel; Alloyed galvanized steel sheet. This kind of steel plate is also made by hot dip method, but after the groove, it is heated to about 500℃ immediately, so that it produces an alloy coating of zinc and iron. This galvanized coil has good coating tightness and weldability.