Experimental investigation and optimization of process parameters for through induction hardening using factorial design of experiments

Induction hardening is a heat treating process that is used to selectively case hardens the surface of material providing improved material properties. In this paper, a novel methodology is introduced to optimize hardness in longitudinal & cross sectional directions over the entire part, instead of selective region, without deforming the surface. The experimental trials are conducted on portable induction hardening machine using completely randomized factorial design model to analyze significant factors. Analysis of variance (ANOVA) technique has been used to study the effect of factors (i.e., Power & Heating Time) & their interaction on Hardness. Optical microscopy has also been performed to find out the change in phases by varying the factors. A mathematical model relating hardness with power and heating time has been developed which can be used for response prediction.