Investigations into series resonant inverter power control parameters for an effective metal induction surface hardening

Abstract

Metal hardening depends on the material properties and the way the heat is being applied; therefore, a careful induction heating system parameter should be carefully selected, and in particular to meet the hardening requirements. In this study, a focus on a cost-effective design of the induction coil and the converter is presented. For that, a sample bar metal made of XC48 is considered. The methodology exploits an indirect procedure. It starts from the coil design according to the metal sample size, followed by a 2D finite element method for parameters and losses determination for the specified hardening depth. The power supply using resonant series converters is evaluated through electrical modelling simulation and which integrates a phase-locked loop scheme to account for load parameter variation. A comparison between the electrical and heat power is conducted to highlight the importance of the inverter control parameters leading to high efficiency and an appropriate and satisfactory hardening profile. A prototype system is built to demonstrate the effectiveness of the approach described.