Study on thermal fatigue stability in microstructure and mechanical property of Fe35Ni35Cr20Mn10 high-entropy alloy wire and pearlite wire at high/medium temperature environment

Abstract

Thermal fatigue stability in microstructure and strength of Fe35Ni35Cr20Mn10 high-entropy alloy (HEA) wire and pearlite wire at 400–700 °C with low cycles was studied. The pearlite wire has a poor stability in microstructure and strength, significantly changing with the temperature. HEA wire has an excellent thermal fatigue stability. After the thermal fatigue at 400 °C and 500 °C, the microstructure and strength does not change at all. Only after the thermal fatigue at 600°C and 700 °C, the microstructure and strength change considerably. Both the values of UTS and YS of the HEA wires after the thermal fatigue at 500 °C and 600 °C are higher than that of the pearlite wires, even both the values of HEA wire in as-drawn state are much lower than that of pearlite wire. Both the thermal fatigue and isothermal annealing at 500 °C and 600 °C resulted in an obvious tempering brittleness in pearlite wire.