Effect of twins on the moderate temperature tensile deformation of a γ′ strengthened Fe-based superalloy

Temperature dependence of the tensile behavior of a Fe-based γ′ strengthened austenitic alloy was investigated from 25 to 900 °C. The stress–stain curves and the microstructures after deformation were studied. The results showed an abnormal tensile behavior with increasing temperature. Serrated stress–strain curves were observed in the samples deformed at temperatures from 300 to 700 °C. Microstructure observation on the deformed samples shows that twins formed during deformation at 300 to 700 °C and became profuse at 700–800 °C. Those twins had a predominant effect on the deformation mechanisms at high temperatures.