Viscoplastic deformation behavior of S32760 duplex stainless steel during the cutting process

Duplex stainless steel (DSS) is composed of the ferrite phase and austenite phase. The mechanical properties of these two-phases differ, and the mechanical behavior during cutting process is complex. Based on Oxley cutting theory, dislocation theory, and nonlinear dynamics theory, combined with experimental and simulation analysis, the manuscript studies the viscoplastic deformation behavior of S32760 DSS during the cutting process. Considering the two-phase viscous characteristics under high strain rate conditions, a viscoplastic constitutive model of S32760 DSS was established. The influence of strain rate change in the shear zone on the chip morphology and the effects of strain, strain rate, and temperature on the microhardness of the two-phases were analyzed. The strain rate strengthening effect of viscoplastic deformation of cutting S32760 DSS was elucidated. The impact of strain, strain rate, and temperature on the dynamic recrystallization of the surface layer material was analyzed, and the microstructure change rule of the machined surface was obtained. The viscoplastic deformation behavior of S32760 DSS was elucidated, taking into account the morphology of the chips, the microhardness, and the microstructural changes.