Semi-Empirical Prediction of Turned Surface Residual Stress for Inconel 718 Grounded in Experiments and Finite Element Simulations

Abstract

The surface residual stress after machining, especially for finishing, has a vital influence on the shape stability and fatigue life of components. The current study focuses on proposing an original empirical equation to predict turned surface residual stress for Inconel 718 material, taking tool parameters into consideration. The tool cutting-edge angle, rake angle, and inclination angle are introduced for the first time in the equation based on the Inconel 718 material turning experiments and finite element simulations. In this study, the reliability of simulation parameters’ setting is firstly calibrated by comparing the residual stresses and chips of the experiments and simulations. The changing trends of turned forces, temperatures of lathe tool nose, and surface residual stress with turning parameters are analyzed. Then, the predictive equation of surface residual stress is proposed considering relationships between the back-rake angle, the side-rake angle, and the tool cutting-edge angle, rake angle, and inclination angle. Moreover, the genetic algorithm optimizes the objective function to obtain the undetermined coefficients in the prediction equation. Finally, the predicted accuracy of the surface residual stress is proven by comparing the experimental, simulation, and prediction values. The results indicate that the predictive equation of surface residual stress has a good accuracy in predicting turned surface residual stress for Inconel 718 materials. The correlation coefficient, R, and absolute average error between the predicted and the simulated value are 0.9624 and 13.40%, respectively. In the range of cutting parameters studied and experimental errors, this study provides an accurate predictive equation of turned surface residual stress for Inconel 718 materials.

Sensitivity analysis of Johnson-Cook material constants and friction coefficient to the surface residual maximum principal stress in turning Inconel 718 simulations

“…The distributions of residual stress along the depth direction after turning were measured by the combination of the X-ray diffraction method and the electrolytic corrosion method to verify the effectiveness of the simulation parameters setting. The process of measurement has been detailed in our previous study [14].…”

INCONEL® Alloy Machining and Tool Wear Finite Element Analysis Assessment: An Extended Review

“…However, the authors stated that the proposed method only applies to low v c in challenging-to-machine materials. Peng et al [150] focused on proposing a novel empirical equation for predicting residual stress on the turned surface of INCONEL ® 718, considering tool parameters such as κ r , γ, and inclination angle (λ s ). Initially, the accuracy of the parameters set for the 3D FEA model through AdvantEdge ® v7.4015 was validated by comparing the residual stresses and chips with the experimental results (Figure 24).…”

Proposal for the identification of residual stresses after turning and hardening of bearing steel

“…Generally, experimental techniques have many limitations, such as laboriousness, time-consumingness, a limited range of sizes and shapes that can be measured, as well as a lack of accuracy dependent on the skill of the operators as well as the capabilities of the machine. Therefore, the development of computational means in the second half of the 20th century led to the development of computational methods aimed at algorithmizing engineering tasks through differential methods, which include finite element methods and integral methods (Maroju and Pasam, 2019;Peng et al, 2021;Ahmadpoor et al, 2022). The paper (Elsheikh et al, 2021) provides a detailed review on residual stresses induced by turning on machined components.…”