Dynamic behavior and a modified Johnson-Cook constitutive model of Inconel 718 at high strain rate and elevated temperature

摘要

Constitutive model is very important in finite element simulation of Inconel 718 cutting process. However, there are few constitutive models for Inconel 718 which are suitable for the cutting process. In this research, firstly, dynamic behavior of Inconel 718 at high strain rate and elevated temperature of the same order as the practical cutting process was obtained using SHPB(Split Hopkinson Pressure Bar) test. In the tests, the strain rate was 5000-11000 s~(-1) and the temperature was 500-800 ℃. Secondly, thermal and strain rate effect were discussed. Strain rate softening effect was found at high strain rate and discussed, and it was temperature dependent. Finally, a modified Johnson-Cook model was established.