Effect of Temperature and Strain Rate on Tensile Behavior of Superalloy Inconel 625

Inconel 625 is identified as one of the most efficient superalloys for various high-temperature applications with operational conditions ranging from cryogenic temperatures to 980 degrees C. The in-depth evaluation of mechanical properties especially tensile and work hardening behavior at various high temperatures and analysis of deformation behavior is essential to utilize the superalloy in various critical applications which form the basis for the present study. Tensile tests were conducted at different temperatures, namely room temperature, 700 degrees C, and 850 degrees C at two different strain rates of 5 x 10-4 and 5 x 10-3 s-1. Serrations were observed at high temperatures, primarily at 700 degrees C. Transmission electron microscopy and x-ray diffraction analysis revealed that the dislocation density as well as slip band distance decreased with increase in temperature. Fractography indicated the presence of dimples at RT which became elongated at high temperature. Fracture mode was essentially mixed fracture at 700 degrees C depicting dimples due to microvoid coalescence and faceted features.