Study of Processing Map of GH4079 Alloy Based on Different Instability Criteria

Using the Gleeble-3800 thermal simulation testing machine, thermal compression simulation experiments were carried out on GH4079 alloy at compression temperatures of 1025–1200°C and rates of 0.001–1 s⁻¹. Based on the experimental data, the Arrhenius ontological relationship model based on the GH4079 alloy was derived. Four kinds of instability criteria, Prasad, Murty, Gegel and Malas, were used to construct the DMM thermal processing map of the alloy under different deformation conditions, and we compared and analyzed the theoretical basis and the prediction results under the above four different instability criteria. By combining the thermal processing map theory with the EBSD microstructure of GH4079 alloy, the optimal thermal processing interval and rheological instability interval of the alloy are predicted, which provides a theoretical basis for the rational development of the thermal processing process window of GH4079 alloy.