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The hot deformation behavior of GH690 alloy is investigated in the temperature range of 950–1200 °C and a strain rate of 10 −3 s −1 to 2 s −1 . It is found that the flow stress increases with strain, and then decreases as it reaches a peak flow stress. On the basis of the experiment data, processing maps are developed using the dynamic materials model (DMM). The processing maps exhibit two domains. One is the stable region occurring in the temperature range of 1120–1180 °C and the strain rate of 0.0325–0.447 s −1 , the other is the instability zone occurring in the temperature range of 950–1180 °C and the strain rate of 0.18–2 s −1 . Under the guidance of the processing maps, a rolling experiment is carried out, and it is found that the yield strength, ultimate tensile strength and elongation of the plate are 565 MPa, 685 MPa and 51.13% respectively.

The hot deformation behavior of GH625 is investigated by a compression test in the temperature range of 950-1150 °C and the strain rate of 10−3-5 s−1. It is found that the flow stress behavior is described by the hyperbolic sine constitutive equation with average activation energy of 421 kJ/mol. Through the flow stresses’ curves, the processing maps are constructed and analyzed according to the dynamic materials model. In the processing map, the variation of the efficiency of the power dissipation is plotted as a function of temperature and strain rate, and the maps exhibit a significant feature with a domain of dynamic recrystallization occurring at the temperature range of 950-1150 °C and in the strain rate range of 0.005-0.13 s−1, which are the optimum parameters for hot working of the alloy. Meanwhile, the instability zones of flow behavior can also be recognized by the maps.