Abstract
This paper presents a study on temperature and stress during the induction hardening process of gears by the dual frequency method. An electromagnetic field analysis, a heat conduction analysis and an elastic-plastic stress analysis during the single and dual frequency induction heating and water cooling processes of gears were carried out by the two-dimensional finite-element method (FEM), considering changes of the magnetic permeability, the resistivity, the thermal expansion coefficient and the yield stress with the temperature. The temperature and stress changes during the induction hardening process by the dual frequency method and the residual stress due to the induction hardening were examined, and compared with those by the single frequency method. The validity of the dual frequency method for the residual stress due to the induction hardening of gears was confirmed.
