Dynamic Constitutive Relation of GH4169 Superalloy Based on Z-A Model

The flow stress-strain curves of GH4169 superalloy at the temperatures of 20-400℃ and strain rates of 1 000-3 000 s^-1 were studied by split Hopkinson bar test. The relationship between stress and strain was described by Zerilli-Armstrong (Z-A) constitutive model, the parameters of constitutive model were determined, and the model was verified by experiments. The results show that GH4169 superalloy had obvious strain rate strengthening effect and temperature softening effect. The relationship between flow stress and strain was nearly linear. The established Z-A constitutive model accurately described the rheological behavior of GH4169 superalloy at different temperatures and different strain rates, and the average value of average relative errors of the model was 2.65%.