What is Galvanised Steel?
Galvanised Steel is the process where a zinc coating is added throughout the body of a steel product. This process is called Galvanisation and protects the steel from corrosion and rusting. Galvanised Steel has a longer life durability compared tonon-galvanised steel due to the zinc components.
When zinc and steel make contact a chemical reaction occurs, the zinc bonds onto the surface of the steel producing a protective layer to the steel.
The process was first developed in England in 1837 where a sheet of steel was dipped in a molten zinc bath. This process is now called hot dip galvanisation.
Hot dip galvanisation is where a steel sheet is dipped into a bath of hot molten. The molten zinc must be maintained at around 450 Degrees Celsius for the chemical reaction to take place. The sheet is then taken out of the molten into the natural atmosphere where zinc oxide is formed.
Other processes are also used to produced Galvanised Steel, but these are not so popular.
- Zinc metal spray – a plasma flame gun is used to spray zinc powder onto a steel sheet.
- Zinc electroplating – a steel sheet is dipped into zinc ion and an electric current is passed through.
- Sherardizing – in this method the steel sheet itself is heated. Rather than dipping into hot molten the steel sheet is then placed into cool zinc powder.
- Mechanical plating – zinc powder, glass beads and a special reducing agent are coated onto the steel sheet, this process bonds zinc onto the steels surface
Galvanised Steel is mainly used to construct or repair large steel structures. This is due to low maintenance, repair costs and durability.