Galvanized coil: a thin steel sheet that immerses the steel sheet into the molten zinc bath to make its surface adhere with a layer of zinc. It is mainly produced by continuous galvanizing process, that is, the rolled steel plate is continuously immersed in the zinc melting bath to make galvanized steel plate; Alloyed galvanized steel sheet. This kind of steel plate is also made by hot dip method, but it is heated to about 500 ℃ immediately after coming out of the groove to form an alloy coating of zinc and iron. The galvanized coil has good coating adhesion and weldability.