Modeling and Microstructural Analysis of Induction Hardened Parts

Abstract

In the present article, an effective procedure of response surface methodology (RSM) is utilized to find the optimal values of process parameters for induction hardening of AISI 1040 steel under three different conditions of the material to predict total case depth. The three material conditions are untreated as-received (rolled), normalized, and tempered. Various process parameters, such as feed rate, current, dwell time, and gap between the workpiece and induction coil are experimentally explored. The experimental results show that the proposed mathematical models can predict the total case depth within the limits of the factors being investigated. The optimal values of process parameters have been verified by confirmation experiments. After ascertaining the optimal sample (corresponding to the best setting of induction hardening process parameters), tensile strength tests were performed so that the comparison could be done between the optimal induction hardened material and material without subjecting to induction hardening. It was concluded that the tempered is the most favorable raw material for making shafts, axles, or other automobile components during induction hardening process as almost finely distributed martensite was observed during scanning electron microscope (SEM) analysis.