Machining induced residual stress prediction during orthogonal cutting of super duplex stainless steel using CEL approach

Super duplex stainless steel (SDSS) exhibits poor machinability due to its high mechanical strength and low thermal conductivity. The strong thermal gradient in the vicinity of the cutting zone during machining generates tensile residual stresses affecting the service life of a component. This necessitates the need for the development of predictive models to estimate the machining induced residual stress in SDSS. This work focuses on predicting residual stress in an orthogonal cutting process using the Coupled Eulerian-Lagrangian (CEL) formulation. Dry orthogonal cutting experiments were performed on SDSS, and the results were validated with the numerical model. The numerical prediction was reasonably accurate, with a force deviation as low as 6.8 %. Even a relatively coarse mesh aimed to reduce computation time did not affect the results significantly. The analysis of thermo-mechanical behaviour during cooling of the workpiece showed that the mechanical effect could highly influence the final residual stress state of the workpiece. The chip thickness analysis showed a varying morphology with an unstable region formed during the initial stage of cutting, followed by a stable region. The overall results predicted using the simulated model are well in compliance with the experimental findings. The estimated residual stress levels can facilitate to assess the SDSS component's service life under various processing conditions.