Hello, friends in this article I am going to tell you about ” The different techniques of heat treatment of steel” This principle based on the fact that change takes place in the internal structure of steel at a specific temperature.
Hard and brittle iron carbide doesn’t become fully combined with iron, however, a temperature until reached about 800°c.
If the steel is heated further, there will be no change in temperature this is due to the fact heat applied is consumed to bring the structure and chemical change in the steel.
The carbon and iron form solid solution all the steel is well below the melting point and is known as decalescene point.
After this point, the temperature further rises again. If the steel is removed from heat and allowed to pull a point appears to be arrested and temperature even may rise slightly and such point is called coalescence point.
The different techniques of heat treatment of steel are given below:-
1) Annealing- To make steel soft annealing is done. It is the process of heating steel to the temperature generally above the critical temperature.
2) Normalizing- It is the process of heating or heat treatment in which steel is heated up to 5°c above the critical temperature and allowed to pull in air. It improves the strength of medium carbon steel and reduces internal stress.
3) Quenching/hardening- The process of heating the steel above the critical temperature and along with cool rapidly and plunging it into the liquid path. In this process roughness or ductility decreases but hardness increases.
4) Tempering- The process of heating the steel to some predetermined temperature between room temperature and critical temperature. During this process toughness and ductility increase but hardness decreases.
5) Surface hardening- In this process outer surface of steel is harden and the poor of steel is only refined.
So, friends, I hope this article on “Different techniques of heat treatment of steel” Remains helpful for you.