A Finite Difference-Based Modeling Approach for Prediction of Steel Hardenability

In this research work an independent finite difference-based modeling approach was adopted for determination of the hardenability of steels. In this model, at first, cooling curves were generated by solving transient heat transfer equation through discretization with pure explicit finite difference scheme coupled with MATLAB-based programing in view of variable thermo-physical properties of 1080 steel. The cooling curves were solved against 50% transformation nose of TTT diagram in order to predict hardening behavior of 1080 steel in terms of hardenability parameters (Grossmann critical diameter, D (C); and ideal critical diameter, D (I)) and the variation of the unhardened core diameter (D (u)) to diameter of steel bar (D) ratio with diameter of steel bar (D). The experiments were also performed to determine actual D (C) value of 1080 steel for still water quenching. The D (C) value obtained by the developed model was found to match the experimental D (C) value with only 6% deviation. Therefore, the model developed in the present work can be used for direct determination of D (I), D (C), and D (u) without resorting to any rigorous experimentation.