Hot dip Galvanized technique
Hot-dip galvanization is a form of galvanization. It is the processing of coating iron and steel with a layer of zinc by immersing the metal in a bath of molten zinc at a temperature of around 840 °F. When exposed to the atmosphere, the pure zinc reacts with oxygen to form zinc oxide, protecting the steel below from the elements.
Galvanized steel is available to high-temperature applications up to 200 °C. The applying of galvanized steel at temperatures above this will result in peeling of the zinc at the inner metallic layer. Electro galvanized sheet steel is often used in automotive manufacturing to increase the corrosion performance of exterior body panels, however a totally different process that tends to achieve lower coating thicknesses of zinc.
Galvanizing protects steel through acting as a barrier between steel and the atmosphere. While zinc is a more electronegative metal compared with steel, which is a unique characteristic for galvanizing which means that when a galvanized coating is damaged and the steel is exposed to the air, zinc can still to protect steel by galvanic corrosion
Galvanized steel is widely used in where corrosion resistance is needed without the cost of stainless steel, and can be identified by the crystallization patterning on the surface.