Steel and iron articles are corroded easily due to atmospheric reaction. To prevent corrosion few methods are adapted. Galvanisation is one among them.
Galvanization is the process of applying a protective layer of zinc on a metal. It is a very common method of preventing the rusting of iron. This can be done by dipping the metal to be protected in hot, molten zinc or by the process of electroplating.
- The protection of iron and steel from corrosion by coating with molten zinc. has been proved for a hundred and fifty years.
- The zinc coating protects from the atmosphere the part’s surface, avoiding corrosion and weathering.
How does it help?
Galvanization helps extend the life of steel parts by forming a membrane between the metal and the air, preventing the accumulation of iron oxide on the steel layer. Galvanization also offers superior corrosion resistance to environmentally exposed parts.
Steps involved in the process
The galvanizing process consists of three basic steps, namely
- Surface preparation
Material is loaded onto jigs before being immersed in molten zinc at about 450 degrees until the working temperature is the same as zinc. During this process, the molten zinc reacts to a series of zinc/iron alloys with the steel surface.
The disadvantages of galvanization are listed below
- It only provides protection from corrosion for a limited amount of time since the zinc layer is eaten up in the process.
- It is not very effective in highly corrosive areas (where cadmium coating can be used instead).