It consists in heating the material at a temperature slightly higher than the austenitizing, then stay for about 15 minutes at this temperature, such as to reach the balance in the microstructural and cooling in still air.
This process is similar to the annealing, but in this case the cooling is more rapid.
The main objective is to refine the crystal grain size of the steel, uniform microstructure and mitigate the extent of layered bands of different phases (structure that is likely to emphasize the behavior of the weakest phase
