Volume 32, Issue 4 (July 2004)
The Response of 1CrMoV Rotor Steel to Service-Cycle Thermomechanical Fatigue Testing
The testing details and results of a series of service-cycle thermomechanical fatigue (TMF) tests on two heats of a 1CrMoV steam turbine rotor steel are described. Two unexpected features of the tests were the development of testpiece necking and, in one heat of the steel, noninteracting creep and fatigue damage. The paper provides a detailed consideration of these aspects.
Both features are attributed to the magnitude of the temperature gradient along the testpiece gage length at peak temperature during TMF cycling. The temperature gradient was acceptable according to the current draft ISO Standard for TMF testing. In the light of the experience described, it is recommended that this existing guidance be reviewed.