Thermo-Mechanical Fatigue of a CrMo Steel Applicable to Steam Turbine Shafts

Abstract The paper is an overview of the work conducted in order to investigate thermo-mechanical fatigue (TMF) performance of a CrMo steel applicable to steam turbine shaft design. Uniaxial TMF tests of tubular specimens under various temperature ranges and phase shifts were carried out. Damage Operator Approach (DOA) proposed by Nagode et al. (2009) was calibrated by low-cycle fatigue experiments and its quality of prediction was verified by the TMF tests. The obtained results show that the DOA predicts the tests with higher range of temperatures (100-600 °C) much better than those subjected to 450-600 °C. The method can distinguish well the effect of different mechanical-to-temperature phase shift.