Study on Forging Permeability of 06Cr19Ni9NbN Steel during Hot Deformation

Abstract

The hot compression tests of 06Cr19Ni9NbN steel were conducted at strains rate of 0.005-5s-1 and temperature of 900-1200 °C on Gleeble1500 thermal mechanical simulation tester. Based on stress-strain data, processing maps of the steel were established. According to the results of processing maps, the optimal process parameters of hot compression were obtained, which lies in the temperature range of 1000-1200°C and strain rate of 0.005-0.1s-1. And then, the process of plane strain compression of 06Cr19Ni9NbN steel was investigated and carried out at the temperature of 1000-1200 °C and reduction ratio of 10%-50%. After the hot compression tests, the room temperature tensile tests were carried out. The results indicated that the grain size and the mechanical properties gradually become stable when the reduction ratio increases to 30%, 34% and 40% at 1200 °C, 1100 °C and 1000 °C, respectively. Finally, a new model was presented to describe critical forging penetration efficiency, which is significant to optimize the steel forging process. Furthermore, the calculated results based on this new model were consistent with experimental results, indicating that the model is suitable to predict the critical FPE for the steel.