Galvanized coil, a sheet steel immersed in a molten zinc bath to adhere a layer of zinc on its surface. At present, it is mainly produced by continuous galvanizing process, that is, the rolled steel plate is continuously immersed in the bath with zinc melting to make galvanized steel plate; this kind of steel plate is also manufactured by hot-dip method, but after being out of the bath, it is immediately heated to about 500 ℃, so as to generate the alloy coating of zinc and iron. This kind of galvanized coil has good adhesion and weldability of coating.