Induction hardening process is widely used to improve fatigue strength of mechanical components that are subjected to cyclic loads in service. The depth of the hardened layer is directed linked with the fatigue and impact strength. So, to improve the mechanical properties in order to preventing fatigue failure in service, it is very important to understand the process and the influence of its parameters.
In this paper, a sensitivity study of the influence of some process parameters on the hardness profile of a crankshaft’s crankpin after induction hardening using will be presented. The proposed simulation method include two stages: heating and cooling. In the first stage, the mechanical component, initially at ambient temperature, is heated by electromagnetic induction to a temperature above the steel austenitization. In the second one, the component is cooled by liquid immersion. The resulting microstructure is calculated using the Johnson-Mehl-Avrami-Kolmogorov model and Sheil’s additive rule for diffusional transformation, while austenite-martensite transformation is calculated by Koistinen-Marburguer equation.
The simulation takes into account thermal properties as a function of temperature and microstructure and electromagnetic properties as a function of temperature and strength of the electromagnetic field (magnetic permeability). The results of the sensitivity study can help in the process setup, decreasing the number of experimental tests.