Effects of Strain Rate on the Cutting of Duplex Stainless Steel S32760

Abstract

Background: The essence of the plastic deformation of the material to be processed during the cutting process is the movement of dislocations. By increasing the density of dislocations, the material’s flow stress inevitably increases by raising the strain rate. Objectives: The three regions are divided quantitatively as thermal activation stage (101-3×103), nonthermal stage (10-3-101), and dislocation damping stage (above 3×103). Analyzing the chip metallographic diagram of the cutting process, it is believed that the strain rate effect is caused by two reasons. Methods: The three areas are based on the speed of growth and the control mechanism, presenting a more detailed and vivid explanation of these three areas. Using Hopkinson pressure bar (SHPB), the strain rate effect of duplex stainless steel S32760 is studied. Results: The greater austenite deformation is caused by the austenite deformation in S32760 compared to the ferrite softening effect and the insufficient softening effect in the plastic deformation of the material. Conclusion: The grain refinement is caused by the adiabatic shear zone from the deformation zone to the transition zone, making it difficult for dislocations to start slipping and increasing the flow stress.