Microstructural evolution and dynamic recrystallization of a nickel-based superalloy PM EP962NP during hot deformation at 1150 °C

Microstructural evolution and dynamic recrystallization mechanism of a nickel-based superalloy PM EP962NP during isothermal compression at 1150 degrees C under different strain rates and strains have been investigated. Results show that continuous dynamic recrystallization can be induced to occur when the strain exceeds 0.36. A processing window with high microstructure stability including the evolution of DRX, y grains and y' precipitates is determined to be hot compression at 1150 degrees C with the strain rate of 0.001 s-1and strains ranging from 0.69 to 1.20. In addition, due to the interaction between dissolution and precipitation, the y' precipitates exhibit inhomogeneous sizes with micron-scale blocky primary y' and nano-scale spherical secondary y'. Moreover, the abundant microstructural information related to the strain rates and strains can provide a reference for obtaining the gradient microstructures by thermo-mechanical processes. (c) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

This study investigates the microstructural evolution and dynamic recrystallization mechanism of a nickel-based superalloy PM EP962NP during isothermal compression at 1150 degrees C under different strain rates and strains. The results show that continuous dynamic recrystallization occurs when the strain exceeds 0.36. A processing window with high microstructure stability, including the evolution of DRX, y grains, and y' precipitates, is determined to be hot compression at 1150 degrees C with a strain rate of 0.001 s-1 and strains ranging from 0.69 to 1.20. In addition, the y' precipitates exhibit inhomogeneous sizes due to the interaction between dissolution and precipitation, with micron-scale blocky primary y' and nano-scale spherical secondary y'. Moreover, the abundant microstructural information related to the strain rates and strains can provide a reference for obtaining gradient microstructures through thermo-mechanical processes.