Principle of Hot-Dip Galvanizing

When steel parts are immersed in molten zinc, a solid solution of zinc and iron initially forms at the interface, which is the process of zinc dissolving and diffusing into the iron substrate. As zinc continues to penetrate, iron and zinc further react to form the intermetallic compound FeZn13, which settles to the bottom of the pot to form zinc slag. Meanwhile, a layer of pure zinc forms on the surface of the steel parts, which crystallizes and solidifies upon cooling to form a complete galvanized coating.