Hold Time-Low Cycle Fatigue Behavior of Nickel Based Hastelloy X at Elevated Temperatures

Hastelloy X, a material used in gas turbines, is subject to complex damage because of creep and fatigue in a high temperature environment during the operation of gas turbines. Although the low cycle behavior of Hastelloy X has been widely investigated, the number of studies focusing on the actual operating conditions of the gas turbine is limited. In this study, the total strain range of the gas turbine at 760 °C and 870 °C was considered as a parameter of the actual gas turbine operation. In addition, tests were performed with a trapezoidal waveform of the total strain to reflect the operation—stop status of the gas turbine with frequent shutdown times. The results of the fatigue test were studied with the Coffin-Manson method and the lifetime prediction equation was derived based on the data. Fractography was performed using scanning electron microscopy (SEM) observation.