Optimization of an induction quenching process using Response Surface approach

The quenching processes are usually, by their nature, very unstable processes, due to the great sensitivity to the product material composition, heating procedure, quenching fluid composition and flow. The paper describes the process set up in order to improve the robustness of an induction quenching process for mass production of an automotive transmission joint. The preliminary step of the study has been the evaluation of the best metric for the process robustness. The experimental part of the study has been carried out in order to investigate which parameters influence the process and which is their relative importance. The factors that could influence the product characteristic has been chosen, among the all, by the application of a process monitoring approach, where historical data were available. The effects and interactions of the remaining factors has been quantified using a Response Surface approach in order to develop a precise process characterization and to allow the definition of optimal process factors tolerances. The process optimization has led to a considerable increase in process robustness and scrap reduction.