Heat Treantment Of Steel

HEAT TREATMENT OF STEEL

I m currently posting various post related to material science ( sry if it bores u ). Material science is basic in the design of everything from machine to product. So, let’s do it one more time.

·         Heat treatment doesn’t mean that u just melt something and give it some shape. Heat treatment consists of heating of material at a certain temperature and then cooled it with different rates. Heat treatment process is used to make a change in mechanical properties of material.

·         Heat treatment of steel is used to make the change in its properties like strength, hardness, wear resistance, ductility, etc. there are four primary methods of heat treatment of steel which is related to each other. Now let’s get started.

A.      ANNEALING: In this method, steel is heated slightly above its critical temperature and then cooled down slowly. Because of this process hardness of steel reduces but its ductility increases.

B.      NORMALIZING: This process is similar to the annealing process but in this heated steel is slowly cooled down in air. This process is used to remove effects of previous heat treatment process.

C.      QUENCHING: In this process, steel is heated to its critical temperature and cooled down rapidly in air or water. Strength and wear resistance of steel can be increased by this process but ductility decreases ( now we need to find a solution of this ).

D.      TEMPERING: In this process, steel is heated below its transformation temperature, and then it is cooled at the desired rate. An advantage of this method is that ductility of steel increases (which decreased in quenching process).