Hot Deformation Behaviour and Recrystallization Model of GH4169 Nickel Base Superalloy

GH4169 superalloy was subjected to thermal compression test at deformation temperature of 900-1 100 ℃ and strain rate of 0.01-5 s^-1, and the microstructure and hot deformation behaviour were studied. A hyperbolic sinusoidal Arrhenius constitutive equation was constructed on the basis of flow curves and a Avrami critical dynamic recrystallization model was constructed. The results show that GH4169 superalloy underwent dynamic recrystallization during hot compression process, and the recrystallization behaviour was more significant at relatively high temperatures and low strain rates. The constitutive equation of GH4169 superalloy was ε=1.37×10¹⁸[sinh(0.003 1σ)]^6.13exp(-4.63×10⁵/RT) when the thermal compression strain reached 0.2. There was a linear relationship between the dynamic recrystallization critical values and the peak values. The Avrami recrystallization model was X_DRX=1-exp{-0.049[(ε-0.035 5)/0.089 9]^2.132} at deformation temperature of 1 100 ℃ and strain rate of 0.01 s^-1.