Modelling on flow stress of plain carbon steel at elevated temperatures

A predictable model to estimate the true stress‐true strain response of plain carbon steel has been made being divided into the two ranges of α‐ and γ‐iron respectively. Again, for the (α + γ)‐range, the mass fraction of the two phases has been taken into consideration. As a result, the peak stress as well as the stress‐strain relation calculated by the model have been found to be in fairly good agreement with those measured by a few investigators under various temperature and strain rate conditions. In particular, concerning the peak stress, it has been confirmed that the model gives a remarkable good conformability, compared with the measured values. Also, the peak stress exhibits the discontinuous change at the A3 point. However, with an increasing carbon content, the discontinuous point tends to shift toward the lower temperature side, and the changing degree becomes slighter.