1. Anodic coating type of coating protect base metal “sacrificially”. Corrosion of iron does not enhance even on breaking “anodic coating” as it heals its film.
2. The iron, coating metal is at lower electrode potential than zinc base metal.
3. Galvanizing is a process of coating iron with thin coat of zinc to protect them from rusting.
4. The iron sheets are cleaned with dilute H2SO4 i.e. pickling to remove impurities. In this process, NH4Cl flux is used.
5. Molten zinc is maintained at 425-430C and it becomes the reason of iron and rusting even of zinc coating is broken in a galvanized iron pipe.