DISCUSSION ON THE APPLICATION OF THE MEDINA MODEL TO THE FLOW CURVE OF HOT DEFORMATION

摘要

The application of the Medina model to the flow curve of hot deformation has been discussed. Using the quick fit function of lstOpt software, the relationship between various model coefficients and a dimensionless parameter Z/A has been built. Using a classification method of the Medina model, the flow curves of 50A1300 silicon steel are built and R∧2 of 0.979436 and the average relative error of 7,3517% are obtained. Then using a recrystallization model of the Medina model, the flow curves of 45K-DDQ are built and R∧2 of 0,974373 and the average relative error of 6,1453% are obtained. In addition, the flow curve model is programmed in Matlab environment so that true stress could be automatically obtained. Finally, the whole fitting method and piecewise fitting method are compared when using the Medina model for solving the model parameters of the dynamic recrystallization flow curve.