Effect of deformation on grain size distribution in process of rolling circle for heavy forgings

The hot compression experiments of roller steel Cr5 were carried out on Gleeble-3500 thermo-simulation machine to research on the effect of deformation on grain size distribution. And finite element models of compression processes were built to acquire the strain distributions in the deformed samples. The microstructures observed by metalloscope show that fine grain sizes were obtained in central regions of the samples due to recrystallization. But coarse grain occurred in the critical strain zones determined by FE simulation. The results prove that FE method can be used to predict the location of coarse grain due to critical deformation of steel Cr5. So, the procedures of rolling circle for large shaft-parts with flat anvil were made and the corresponding FE models of rolling circle processes were established. The FE simulation results indicate that the technology of rolling circle with flat anvil can avoid generating coarse grain caused by critical deformation.