What two treatments determine the internal structure of ferrous metals?

The two treatments to determine the internal structure of ferrous metals are:

• Heat treatment (by heating)
• Cold treatment (by cooling)

Heat treatment: It is used to know the chemical composition of the steel. When a steel is heated above its critical point of temperature there will be some changes occur in its internal structure. When the temperature gets increased the carbon particles present in the iron matrix will form solid solution known as austenite.

Cold treatment: After heating the steel above its critical temperature point then the steel is allowed to cool in atmospheric air.  If the cooling process of the iron gets slow then the presence of carbide particles will become lesser, due to this the steel will become soft.