Characterization of One-and-a-Half Side Galvanized Steels for Automotive Applications

The extensive use of hot dip galvanized steels as a corrosion resistant replacement for cold rolled sheet steel has necessitated much research and development as to their character, composition and their behavior under stamping conditions. This paper presents parts of a study of one such material; hot dip differentially coated galvanized steel for exposed automotive applications. Included is the characterization of the coatings; a free zinc side for perforation corrosion resistance and a thin zinc-iron alloy side for exposed cosmetic corrosion resistance. The behavior of the coatings under some fabrication conditions is described, as well as its painted appearance. The properties and choice of the base metal are discussed as well as the resulting forming performance.