Flow Behavior and Processing Maps of a Low-Carbon Steel During Hot Deformation

The hot isothermal compression tests of a low-carbon steel containing 0.20 pct C were performed in the temperature range of 973 K to 1273 K (700 °C to 1000 °C) and at the strain rate range of 0.001 to 1 s⁻¹. The results show that the flow stress is dependent on deformation temperature and strain rate (decreasing with increasing temperature and/or increasing with increasing strain rate). The flow stress predicted by Arrhenius-type and artificial neural network models were both in a good agreement with experimental data, while the prediction accuracy of the latter is better than the former. A processing map can be obtained by superimposing an instability map on a power dissipation map. Finally, an FEM model was successfully established to simulate the compression test process of this steel. The processing map combined with the FEM model can be very beneficial to solve the problems of residual stress, distortion, and flow instability of components.