Optimization of process parameters for induction heat treating by means of numerical simulation

Experimental investigations indicate that the process parameters for the induction heat treatment have an enormous influence on the resulting component properties like hardness distribution, residual stress distribution and fatigue strength. The selection of optimum hardening parameters via experiments is time-consuming and costly. Powerful hardware and software perform simulation runs for the induction heat treating process to help chose optimal parameters for a particular component. These tools can shorten development cycles and reduce time-consuming and expensive experimental parameter studies. Their potential may also be used to increase production rates, improve the fatigue properties and define appropriate quantities for quality control. A method to simulate the induction hardening process based on the finite element method is explained and the necessary input quantities are introduced. Various examples illustrate the application of the method. Numerical simulation results are co mpared to experimental data from residual stress measurements (X-ray) and extensive fatigue testing. Appropriate parameters to introduce favorable residual stress distributions depend on component geometry (notches) and type of loading (bending, torsion) among other factors. The numerical simulation of heat treatment processes is an important step towards a meaningful prediction of component behavior and will gain importance for future design processes.