Investigation of relative magnetic permeability as input data for numerical simulation of induction surface hardening

This paper is devoted to the investigation of relative magnetic permeability as input data for numerical simulation of induction heating for surface hardening. The relative magnetic permeability of ferromagnetic steel heavily depends not only on such parameters as magnetic field intensity and the process temperature, but also on the actual chemical composition of steel. Information contained within present reference books is restricted to data about plain carbon steel e.g. C45. These properties can significantly differ from the properties of steel actually being used and therefore cannot always be recommended for implementing to a numerical model. A method of relative magnetic permeability determination has been developed and applied in order to increase accuracy and reliability of material data. At the same time, because of some special features of induction heating for surface hardening, the sensitivity analysis has been carried out to estimate the accuracy required in determining the properties in order to implement them to numerical models.