Phase-modulated currents in induction heating

Purpose - The purpose of this paper is to determine technological potential of using multi-frequency electromagnetic fields for the optimization of induction heating process. Design/methodology/approach - The aim of the research is achieved by using phase-modulated current feeding the solenoid that excites the magnetic field. In this case, the magnetic field, side by side with the carrier frequency, contains frequency spectrum arising due to modulation. At that, spectral components possess different penetration depths, which ensures a more uniform current density distribution over the cross-section of the heated object. The results are obtained using theoretical analysis of electrodynamic and thermal processes in the heated body. Findings - In the course of the work, a basic possibility of the objective realization is established, and its high enough efficiency is achieved using a sufficiently large range of modulation parameters. Practical implications - The described method can significantly improve the technology of thermal treatment of metals and alloys liable to the formation of surface defects due to extreme temperature stresses. Originality/value - The novelty of the paper consists in the use of phase-modulated currents in induction heating.