Flow Behavior and Constitutive Modeling of Delta-processed Inconel 718 alloy

The flow behavior of delta-processed Inconel 718 was studied in temperature range of 900–1060 °C and strain rate range of 0. 0.01–0.5 s−1. The effects of friction and temperature on the compressive deformation behavior were investigated, and the flow stress-strain error caused by friction was revised. The results showed that the effect of the friction was obvious with increasing strain rate and decreasing deformation temperature. The revised flow stress is decreased by increasing temperature and decreasing strain rate and exhibits a typical dynamic recrystallization behavior. The constitutive model has been developed through a hyperbolic-sine Arrhenius type equation to relate the flow stress, strain rate and temperature. The influence of strain has also been incorporated by considering the variation of material constants as a function of strain. The prediction accuracy of developed constitutive model has been assessed using standard statistical formulae. According to the analysis results, the proposed deformation constitutive equation gives an accurate and precise estimate of flow stress of delta-processed Inconel 718 alloy.