Galvanized coil, the thin steel sheet is immersed in a molten zinc tank to make a layer of zinc thin steel sheet adhered to its surface. It is mainly produced by continuous galvanizing process, that is, the rolled steel sheet is continuously immersed in a plating tank with molten zinc to make a galvanized steel sheet; Alloy galvanized steel sheet. This steel sheet is also made by hot dip method, but after leaving the tank, it is immediately heated to about 500℃ to form an alloy film of zinc and iron. This galvanized coil has good coating adhesion and weldability.