Coating iron with zinc is a process known as galvanisation. This protective coating helps prevent rust and corrosion.
What is Galvanisation?
Galvanisation is the process specifically used for coating iron or steel with a protective layer of zinc. This technique significantly extends the lifespan of iron objects by shielding them from environmental elements that cause rust.
How is Iron Coated with Zinc?
According to the reference provided, there are primary methods to apply the zinc coating during the galvanisation process:
- Spraying: A layer of zinc can be coated onto the iron object with the help of spraying. This method is often used for larger structures or for touch-ups.
- Dipping in Molten Zinc: A layer of zinc can be coated by dipping the iron object in molten zinc. This is a very common method, known as hot-dip galvanising, where the iron reacts with the molten zinc to form a series of zinc-iron alloy layers, followed by a layer of pure zinc on the surface.
Both methods create a barrier that protects the underlying iron.
Why Coat Iron with Zinc?
The primary reason for coating iron with zinc is corrosion protection. Zinc serves as a sacrificial anode, meaning that if the coating is scratched and the base metal (iron) is exposed, the zinc will corrode preferentially, protecting the iron until the zinc layer is consumed. This makes galvanized iron highly durable, especially in outdoor or humid environments.
This process is widely used for manufacturing items like:
- Corrugated roofing sheets
- Fencing
- Pipes
- Automotive parts
- Nuts, bolts, and fasteners
By applying a zinc coating, iron objects gain enhanced resistance to rust, ensuring longevity and reducing maintenance needs.
