The difference between normalizing and annealing

Normalizing:

Normalizing is a heat treatment process which is used to make metal more ductile and tough and helps to remove impurities. Thermal and mechanical hardening processes decrease ductility and increase hardness of steel parts. Therefore, normalizing can reform the MICROSTRUCTURE into more ductile structures. This reduces the RESIDUAL STRESS of the workpiece. Further, normalizing makes the steel more formable and machinable.

Normalizing heat treatment helps to remove impurities and improve ductility and toughness.

Annealing:

Annealing, treatment of a metal or alloy by heating to a predetermined temperature, holding for a certain time, and then cooling to room temperature to improve ductility and reduce brittleness. Process annealing is carried out intermittently during the working of a piece of metal to restore ductility lost through repeated hammering or other working. Full annealing is done to give workability to such parts as forged blanks destined for use in the machine-tool industry. Annealing is also done for relief of internal stresses. Annealing temperatures vary with metals and alloys and with properties desired but must be within a range that prevents the growth of crystals.

What Is The Difference Between Annealing and Normalizing?

Normalizing is very similar to annealing as both involve heating a metal to or above its recrystallization temperature and allowing it to cool slowly in order to create a microstructure that is relatively ductile. The main difference between annealing and normalizing is that annealing allows the material to cool at a controlled rate in a furnace. Normalizing allows the material to cool by placing it in a room temperature environment and exposing it to the air in that environment.

This difference means normalizing has a faster cooler rate than annealing. The faster cooler rate can cause a material to have slightly less ductility and slightly higher hardness value than if the material had been annealed. Normalizing is also generally less expensive than annealing because it does not require additional furnace time during the cool down process.