Resonant inverter power and coil parameters determination for metal surface hardening

In this paper, a design of a resonant inverter is conducted with the induction coil system for induction surface metal hardening. Considering a sample metal rod made out of AISI 1038 material, we propose to determine the required power size of the inverter and the induction coil specifications, which would enable to deliver the necessary heat to achieve the appropriate hardening profile. In this approach, the system operates in the medium resonant frequency range of 1-30 kHz, and with a penetration depth spanning from 0.5-1. The approach combines a 2D numerical analysis for eddy currents losses determination in the first stage, followed by an electrical circuit analysis to account for the magnetic and electrical aspects of the system. To demonstrate the effectiveness of the approach, a comparison is performed between the predicted and the experimental performances using a low power prototype for induction hardening applications.