Optimization of the edge effect of 4340 steel specimen heated by induction process with flux concentrators using finite element axis-symmetric simulation and experimental validation

This research is performed by 2D axis-symmetric finite element simulation based on the coupling of electromagnetic fields and heat transfer applied on 4340 steel specimen with flux concentrators heated by induction process. The model is built using COMSOL software based on an adequate formulation taking into account the material properties and process parameters. The obtained induced currents and temperature distributions are analyzed versus the geometrical dimensions of the model. The originality of this paper lies in the exploitation of simulation data using classical modeling and the optimization techniques to optimize the hardness profile according to geometrical factors. The proposed method is based on finite element simulations and adequate objective function able to converge to the optimal linear hardness profile. The results demonstrate that the final hardness profile can be quasi-uniform with a narrow flux concentrator gap when the gap between the master part and the inductor is larger. This overall study allows a good exploration of hardness profile linearity under various geometrical dimensions and permits a good comprehension of induction heating with flux concentrator behavior.