Electromagnetic‐Thermal Modeling of Induction Heating of Moving Wire

The strength in a high carbon wire is attributed to the pearlitic microstructure, which is required for ease of wire drawing. During cold drawing of high carbon steel wires, residual stress develops which has to be relieved in order to obtain the desired mechanical properties. To achieve this, the wire is passed through a closed loop online an induction furnace at a particular speed in order to heat it to a uniform temperature range. This research work presents the electromagnetic‐thermal modeling of the induction heating of a moving wire based on the finite element method using the software package, COMSOL MultiphysicsTM. The furnace had a complicated geometry for the coils and this is, perhaps, for the first time an exhaustive study which is being reported. A unique grid generation technique was developed considering the skin effect. This work is aimed at enabling modeling of the process and will in turn be useful when defining individual parameters affecting the temperature distribution in a component, subjected to induction heating. The temperature distribution in the work piece depends primarily on parameters like coil position, line speed, frequency of the current, thermal and magnetic properties of the work piece, and so on. The impact of power supply frequency and line speed were studied during the heating of the moving wire (workpiece). An in‐situ customized furnace of lower capacity was developed to carry out the validation experiments. The present modeling results are validated with online plant trial data and found to be in good agreement. Finally, the desired mechanical property achieved during trials was confirmed through tensile testing.