Galvanization, or galvanisation, is the process of applying a protective zinc coating to steel or iron, to prevent rusting.The most common method is hot-dip galvanization, in which parts are submerged in a bath of molten zinc.alvanizing protects in two ways: 1  It forms a coating of corrosion-resistant zinc which prevents corrosive substances from reaching the more delicate part of the metal. 2  The zinc serves as a sacrificial anode so that even if the coating is scratched, the exposed steel will still be protected by the remaining zinc.