Predicting the strain hardening behavior and constructing processing maps of a lightweight Fe–Mn–Al–C steel through phenomenological modelling

This research deals with predicting the strain hardening behavior and constructing the processing maps of a lightweight steel over a wide range of temperature. To achieve this, the tensile tests were conducted at temperatures of 100 °C–1100 °C under strain rates of 0.001, 0.01, and 0.1s−1 up to fracture. In order to predict the deformation behavior of the lightweight steel, strain compensated Arrhenius-type models were employed. Considering the wide temperature range under investigation, the activation energies and strain rate sensitivity coefficients substantially varied, therefore, three different temperature ranges of 25–200 °C, 300–600 °C, and 700–1000 °C were considered for the prediction of the flow stress level. To evaluate the accuracy of the applied models, the (i) root mean square error (RMSE), (ii) average absolute relative error (AARE), and (iii) correlation coefficient (R), were calculated as well-known statistical parameters. A good agreement was observed between the predicted and actual flow stress. Employing the predicted data, the strain hardening curves were plotted and power dissipation/instability maps were constructed at various strain levels and temperature ranges. The rapid hardening regions, the regions with high efficiency and instability regions were identified which would be valuable for industrialization of the experimented material.