Short Essay on the growth of Iron and Steel Industry

Iron and Steel is the key industry of the modern world. It is the foundation of machines, machine tools, tele-communication equipment, building of different modes of transport, agricultural machines, military hardware etc.

It is used in the construction of bridges, tunnels, dams and buildings. In fact the industry influences every walk of human life. It would be very much correct to say that Iron and Steel industry is the backbone of economic, industrial and political development of the world.

Requirement of the Industry

For the development of Iron and Steel industry, the basic requirements are:

(i) Availability of raw material like iron ore, limestone, dolomite and manganese.

(ii) Availability of source of power.

(iii) A large supply of water for tempering steel.

(iv) Availability of cheap land, labour, capital and technical know-how.

(v) A market for sale of steel.

Properties of Iron and Steel

(1) Strength :

It is used for structural steel, griders, rail trackers, engines, boilers, pipes etc. Sydney bridge is made of 50,000 tons steel.

(2) Elasticity :

It is used in all durable goods like machines, automobiles, locomotives, tankers, ships etc.

(3) Ductility :

It can be drawn into iron bars, wires or rolled into plates.

(4) Low cost of production :

Ore is enormous in the world. Iron is cheaper than tin.

(5) Easy to produce :

Mining is easy.

(6) Alloyability :

It can be alloyed with many other metals.

Type of Iron and Steel

1. Pig Iron.

Moulds, pigs and rough iron bars are called pig iron. It has 4% carbon and small quantities of sulphur, manganese, phosphorous and silicon.

2. Cast Iron is simply pig iron which has been retreated and poured into moulds. It is brittle because of impurities.

3. Wrought Iron.

It is made by reheating pig iron and removing impurities like carbon. It is pure iron. It is very tough.

5. Steel.

It is made by reheating pig iron and then adding controlled amounts of carbon between 0-3%-2-2% and ferro alloys like nickle, chromium, vanadium etc.

6. Cast Iron.

Once the carbon content exceeds 2%, steel becomes cast iron.

7. Scrap.

Worn out, rotten machine parts, bars, tins, cans, condemned automobiles etc.

The equipment which is used to transform iron into steel by removing the impurities is called convertor.

An Englishman, Bessemer, developed the first convertor. Now there are many other convertors in operation.

Steel is made by:

(i) Bessemer process

(ii) Open hearth process

(iii) Electric furnaces

(iv) Oxygen process.

Integrated steel mills are those which combine on one place, the smelting of iron in blast furnaces, making of steel and production of some finished products like sheets, pipes, girders etc.