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

Abstract

The residual maximum principal stress on the surface of components affects the service life and corrosion resistance of parts. The current study focuses on the sensitivities of the Johnson-Cook (JC) constitutive constants and the friction coefficient to the surface residual maximum principal stress during turning Inconel 718 with low-level and high-level cutting parameters. Two sets of three-dimensional (3D) turning simulations and experiments are carried out under low-level and high-level cutting parameters to verify the credibility of the simulation parameter settings. Then, the above sensitivities are analyzed based on eighteen sets of 3D turning simulations designed by the Taguchi approach. When the cutting parameters are low-level, the strain hardening coefficient B is highly sensitive to the residual maximum principal stress. Besides, under high-level cutting parameters, the strain hardening coefficient B, the strain hardening index n and the thermal softening coefficient m have high sensitivities, in which the thermal softening coefficient m is the most sensitive, followed by the strain hardening coefficient B. The present work provides a direction for studying the influence of surface residual maximum principal stress on the service life of components by adjusting the JC constitutive constants and the friction coefficient.