Galvanized coil, the thin steel plate is immersed in the melting zinc tank, so that the surface of the thin steel plate with a layer of zinc. At present, continuous galvanizing process is mainly used in the production, that is, the rolling steel plate is continuously immersed in the melting zinc plating tank made of galvanized steel plate; Alloyed galvanized steel sheet. This steel plate is also made by hot dipping, but immediately after being taken out of the tank, it is heated to about 500 ° C to form an alloy film of zinc and iron. This galvanized coil has good coating tightness and weldability.