Flow Behavior for FGH96 Superalloy during Two-Pass Hot Deformation and Constitutive Relationship

The hot deformation behavior and microstructure evolution of FGH96 superalloy has been investigated during two-pass hot deformation in the temperature range of 1050 similar to 1125 degrees C and the strain rate range of 0.001 similar to 0.1 s(-1)with the strain of 45%+25% by an isothermal interrupted hot compression test via Gleeble-1500. A constitutive relationship including strain, strain rate and temperature was established. The results show that the first and the second pass hot deformations have the same change rules. The solution of gamma' and the growth of grain have an effect on both of the two pass hot deformations. The curves of true stress-true strain between mathematical model and measured values are preferably fitting. The mathematical model can reflect the flow stress precisely under different conditions. A better deformed microstructure can be achieved when the temperature is between 1075 and 1100 degrees C, and the strain rate between 0.01 and 0.1 s(-1).