Deformation characteristics of δ phase in the delta-processed Inconel 718 alloy

The hot working characteristics of δ phase in the delta-processed Inconel 718 alloy during isothermal compression deformation at temperature of 950 °C and strain rate of 0.005 s− 1, were studied by using optical microscope, scanning electron microscope and quantitative X-ray diffraction technique. The results showed that the dissolution of plate-like δ phase and the precipitation of spherical δ phase particles coexisted during the deformation, and the content of δ phase decreased from 7.05 wt.% to 5.14 wt.%. As a result of deformation breakage and dissolution breakage, the plate-like δ phase was spheroidized and transferred to spherical δ phase particles. In the center with largest strain, the plate-like δ phase disappeared and spherical δ phase appeared in the interior of grains and grain boundaries.