Hot deformation and processing maps of X-750 nickel-based superalloy

The deformation behavior of X-750 superalloy was investigated using the hot compression test in the temperature range of 850–1050 °C, and strain rate of 0.1–50 s−1. The experimental results show that the flow stress of superalloy is significantly sensitive to the strain, the strain rate and the deformation temperature. Using dynamic materials model the processing maps of X-750 superalloy at strain of 0.1, 0.3 and 0.5 were established respectively. Microstructure observations reveal that the grain size as well as the volume fraction of the recrystallized grains increased at higher deformation temperature or lower strain rate. At strain of 0.5, the flow instability domain mainly located at lower temperature which is associated with shear band formation and flow localization. The optimum parameters for hot working of the alloy are deformation temperature of 1000–1050 °C and strain rate of 0.1–1 s−1 according to the processing map and microstructure at true strain of 0.5.