Abstract
Induction hardening serves as one of the best mass production processes used recently due to its ability to quickly generating high-intensity heat in a well-defined location of the part. Numerous advantages of this method make it a reliable technique to produce a thin martensite layer on the part surface that has compressive residual stresses. In this regard, the presented study is devoted to investigating utilizing induction heating for surface hardening of AISI 4340 steel disc. The purpose is to evaluate the performance of magnetic flux concentrators and the effects of the induction process parameter on the case-depth and edge effect in the surface hardening of the disc. Once the proper range of parameters is defined, Taguchi experimentation planning is used to frame comprehensive experimentation with the minimum possible trial. Then, the case-depth of discs is evaluated on their cross-sections (edge and middle plane) through hardness profile measurement of samples using a micro-indentation hardness machine. The results are then statistically analyzed using Analysis of Variance (ANOVA) and Response Surface Methodology (RSM) to determine the best combination of parameters to achieve maximum case-depth yet minimum edge effect. The goodness-of-fit regression models are then developed to predict the case-depth profile as a function of machine parameters based on linear regression utilizing case-depth responses in the edge and middle plane of discs. Results imply that maximum case-depth with minimum edge effect can be produced by using the highest heating time along with the average amplitude of the power, axial gap, and radial gap. This study gives a good exploration of case-depths optimized by setting up process parameters when magnetic flux concentrator is utilized, thus, a guideline to reduce discs edge effect in induction surface hardening application is given.
A novel investigation into the edge effect reduction of 4340 steel disc through induction hardening process using magnetic flux concentrators
