PREDICTION AND RESEARCH OF DYNAMIC RECRYSTALLIZATION EVOLUTION IN HADFIELD STEEL TURNOUT CORES

The microstructure uniformity of the Hadfield steel turnout core during forging is the key factor affecting the quality of the formed parts. The peak strain model, critical strain model and dynamic recrystallization model of the material were established using the stress-strain curve obtained with a hot compression experiment. The dynamic recrystallization model was used to predict the evolution of the grain size and dynamic recrystallization volume fraction during the forging process. The influence of process parameters on the microstructure uniformity of turnout core forgings was studied and optimized using the orthogonal test. The accuracy of the dynamic recrystallization model and numerical simulation was verified with the measurement of the grain size and comprehensive mechanical properties of the forging parts.