Galvanizing is the process by which an adherent coating of zinc or zinc and iron is produced on the surface of iron or steel products by immersion in a bath of molten zinc. The zinc coating is anodic relative to the iron or steel and corrodes preferentially, forming a protective zinc-oxide layer. For more information try the book "Corrosion and Electrochemistry of Zinc" by Xiaoge Gregory Zhang (1996, Springer).