Low-Cycle Fatigue Behavior Of Alloy 800h At A High Temperature Of 850 Degrees C

As part of a series of studies on the high temperature low cycle fatigue properties of Alloy 800H, the objective of the present study is to investigate the low cycle fatigue behavior of Alloy 800H at high temperature of 850 degrees C and evaluate the fatigue life. Systematic experiments were conducted to understand the low-cycle fatigue behavior of this alloy at high temperature of 850 degrees C. Low-cycle fatigue tests were conducted under fully reversed axial total strain range control mode employing a triangular waveform, under constant strain rate of 10(-3)/s with four different total strain ranges of 0.6 %, 0.9 %, 1.2 % and 1.5 % at 850 degrees C. The low-cycle fatigue life decreased with increasing total strain range. Strong influence of total strain range on low-cycle fatigue life and cyclic stress-strain behavior was observed. And also, the fatigue life was evaluated by the Coffin-Manson method. Finally, the fracture surface was analyzed using scanning electron microscope (SEM) and optical microscope (OM).