Hot-Dipped One-Side Galvanized Steel Sheet Produced by a New Stop-Off Coating Process

A new hot-dipped one-side galvanized steel suitable for automotive body material has been developed. This steel is produced in a continuous galvanizing line of the inline anneal type by using a special stop-off coating material comprised of water glass, H₃Bo₃, MgO and NaOH. The galvanized side of the product exhibits the same properties as regular two-side galvanized steel. The bars side of the product has good appearance and better corrosion resistance than conventional cold rolled steel. This is due to the cleaning action of the stop-off coating during annealing of the steel.