A simulation study on deformation behavior of IN690 super alloy tube during hot extrusion process

Based on the results of isothermal compression test of IN690 super alloy for constitutive relationship and ring compression test for interface friction factor, a finite element model for Ni-based super alloy IN690 tube during hot extrusion process is established by using DEFORM-2D. High temperature, high speed and high load are considered in the model. Extrusion load in steady process for the typical size is in good agreement with the measured result. The extrusion load, billet temperature field, stress field, strain field and the strain rate field during deformation process are obtained. Simulation results show that extrusion process can be divided by upsetting, filling, steady-state extrusion and end-stage extrusion. Little change of temperature occurs in upsetting and filling stages extrusion. The maximum temperature increase of billet appears at peak load and stable value 50°C is obtained in steady-state extrusion. Temperature decrease of billet rises up as extrusion process goes on. The maximum of equivalent strain appears at peak load. The maximum equivalent stress increases rapidly to a peak value in initial stage, and rises up slowly in steady-state extrusion process. Equivalent strain and equivalent strain rate keep unchanged in steady-state extrusion.