Effect of thermal cycle shocking on microstructure and mechanical properties of Stellite 12 (Co-29Cr-2.3C-3W) cobalt based alloy

In order to investigate the effects of thermal cycle shocking on microstructures and mechanical properties of Stellite 12 Cobalt based alloy, the thermal shocking with various cycles of 1, 15, 30, 45…150 cycles at the peak temperatures of 650 °C, 700 °C and 800 °C were performed, and the corresponded microstructure characterization, tensile, bending and hardness experiments after the thermal shocking with various cycles at various temperatures were systematically investigated. Results indicated that the microstructure and hardness have not changed after the thermal cycle shocking processes, the tensile strength and flexure strength decrease with the increase of thermal shocking cycles, when thermal shocking cycles reaches 105 cycles, the flexural strength decreases to 30% of original flexure strength, which is attributed to the 23~30% cracking areas produced during thermal cycle shocking processes.