Estimation of Residual Stresses and Corrosion Behavior in Machining of Nickel-Base Superalloy

Abstract

ABSTRACT

Inconel 718, a representative nickel base superalloy, is widely used plants, petrochemical industries and Chemical due to its high temperature endurance properties and excellent corrosion resistance. However, the turning of Inconel 718 produces more generations heat in the cutting zone than that of greatest other materials and alloys which makes this material pruned to surface defects. The aim of this study is to evaluate the effect of different turning parameters i.e. cutting speed (v),feed rate (f) and depth of cut(d) on the responses i.e. surface integrity including surface roughness(Ra), microhardness(HV) ,residual stresses and corrosion behavior for nickel base superalloy (Inconel 718) during dry turning using coated carbide tools. Experiments was designed using design of experiment (DOE) Taguchi method and experimental runs are conducted for various combinations of turning parameters to find the optimum machining parameters that achieves better surface quality with minimum corrosion rate. Analysis of variance (ANOVA), correlation and regression techniques are employed to determine the significance turning parameters. In addition, a numerical model using 3D finite element method (FEM) is performed by ABAQUS software to examine the machined surface temperature II distribution and residual stresses induced by turning and the results of the models are validated by comparison them with experimental results. The comparison showed a good agreement more than (90%) between the 3D FEM modeling of the oblique machining and experimental results. Moreover, the results showed that the feed rate has the most significant(66%) effect on the surface roughness and the best surface quality is achieved using the highest cutting speed and lowest feed rate and depth of cut. The cutting speed has the most significant(56%),(63%)and (50%) respectively effect on the residual stresses(Rs), microhardness(Hv) and machined surface temperature . Also, it was found that the temperature generation during high-speed turning of is found to play a major role in residual stress magnitude. The surface roughness and compressive residual stresses are very important factors which play major effect on the corrosion behavior of Inconel 718. In this way, the feed rate is showed the most significant(72%) factors for minimizing the corrosion rate in Inconel 718 alloy .The results obtained by this research will be fruitful for various industries and researchers who are working in this field.