The martensitic transformation is one of the phase transformations occur in solid state. It plays a significant role in quality modifying heat treatment process of steels.

Martensitic transformation occurs during quenching of carbon steel but we also can observe different type of ordered martensitic transformation so deformation induced, isothermal or thermoelastic in different type of alloys.

The most important behaviour of stainless steel is a god corrosion resistance tanks to the high Cr conposition beside the improved Ni concentration and small C. These steels have mainly austenitic structure. The metastable austenite may transforms into martensite induced by deformation, cooling, or isotherm treatment at room or below temperature.

Depends on the concentration and other circumstance a -martensite (BCC) or
e -martenzite (hexagonal) could form. The kinetics of the transformation could be: g ® e ,
g ® e ® a and g ® a .

The formed martensite transfers back to austenite during heating. This back transformation is ordered too.

The formed structure by the different treatment could change the mechanical properties of steel and has effect on the corrosion.