Galvanising - is widely used in applications where rustresistance is needed. Hot-dip galvanizing is a form of galvanisation and is the process of coating iron, steel or aluminium with a thin zinc layer. When exposed to the atmosphere, the pure zinc (Zn) reacts with oxygen to form zinc oxide, which further reacts with carbon dioxide to form zinc carbonate , a usually dull grey, fairly strong material that stops further corrosion in many circumstances, protecting the steel below from the elements.