The ‌ steam turbine rotor is a very significant rotating part inside the steam turbine and it is the one that makes the transformation of thermal energy (from steam) into mechanical energy possible. It is a part under extreme working conditions such as high temperature, high pressure, as well as continuous rotational stress. Hence, the forging of the rotor and the material used for it should be of very high quality and free of any defect for the safety and efficiency of the turbine.