Guidelines for Welding Galvanized Steel

Hot dip galvanizing of steel components after fabrication is well known as an inexpensive method of corrosion protection. The coating is metallurgically formed in a bath of molten zinc. The structure of the coating, formed by the interdiffusion of zinc and iron, provides good adhesion to the steel and, because the intermetallic layers are very hard, it also provides good abrasion resistance. Many structures are galvanized after they have been welded in order to achieve optimum corrosion protection from the galvanized coating. However, most products in the precast/prestressed industry can easily and satisfactorily be welded after fabrication by practicing the techniques outlined in this article. The following guidelines and information are intended to assist in employing the correct techniques to ensure a high quality product or job.