Hot-dip galvanizing is the process of coating iron, steel, or aluminum with a thin zinc layer, by passing the metal through a molten bath of zinc at a temperature of around 460°C.  When exposed to the atmosphere, the pure zinc (Zn) reacts with oxygen (O2) to form zinc oxide (ZnO), which further reacts with carbon dioxide (CO2) to form zinc carbonate (ZnCO3) that stops further corrosion, protecting the metal below from the elements.  Galvanized steel is widely used in applications where rust resistance is needed.