Question

The process of coating Zinc over Iron is known as ________.

A. Calcination

B. Metallurgy

C. Tinning

D. Galvanization

Answer 1

Hint: Iron surfaces start to corrode after sometime when in the presence of moisture and oxygen. To prevent this from happening, we coat the iron with Zinc layers.

Complete step by step answer:

The process of coating Zinc over Iron is known as Galvanization. It is the process in which a protective layer of Zinc is applied to Iron or Steel. This is done to prevent the iron and steel from rusting.

- When iron is left in a place where the water content in air is high, it leads to the formation of rust.

- The iron atoms on the surface bond with the atoms of oxygen, in the presence of moisture, which results in the formation of iron oxides as products.

- The mixture of iron oxides formed on the surfaces of iron objects is known as rust. It is a red flaky substance that can crumble easily into powder when touched.

- It degrades the strength, appearance and permeability of the material. And since many of the materials around us are made up of iron, it's very important to preserve them. Due to this reason, galvanization is carried out.

- One of the methods of protecting iron made materials from corrosion is through hot-dip galvanization. In hot-dip galvanization, all the surfaces of the material are dipped into, and completely coated with, molten zinc.

- Zinc metal is used for the process of galvanization because the corrosion of zinc is very slow, which gives it an extended life while it protects the base metal.

- Due to the alloying of the Zinc to the iron, cathodic protection occurs. This ensures that small areas of iron which may be exposed to damage are not compromised by rust.

- The cathodic protection will last as long as the zinc layer is present.

Hence, option (D) is the correct answer.

Note: There are various other methods through which the rusting of iron can be prevented. Coat paints can be applied to the iron surface which will prevent the iron from rusting. But there are advantages to using galvanization. It requires less maintenance and lowest long term cost. It has a longer life expectancy.