Study on formation mechanism and regularity of residual stress in ultrasonic vibration grinding of high strength alloy steel

Abstract

The surface residual stress of the part has a crucial influence on its service performance. This paper studies the formation mechanism of residual stress in Ultrasonic Vibration Grinding (UVG) of high strength alloy steel, and obtains the correlation law between processing parameters and residual stress. First, based on the kinematics analysis of UVG, the formulas of ultrasonic grinding force and ultrasonic grinding transient moving heat source temperature field are analyzed. A thermal-mechanical coupled ultrasonic vibration grinding residual stress prediction model was established by FEM and verified by experiments. Second, the thermal behavior of the workpiece surface during UVG is analyzed, and the formation mechanism of the residual stress on the workpiece surface is explained. Finally, combining simulation and experimental results, a comprehensive correlation law between multiple grinding process parameters and residual stress is obtained. The research results show that compared with common grinding (CG), UVG can reduce the grinding temperature by about 8%. Both UVG and CG will reduce the original compressive stress on the surface, but UVG can make the surface of the workpiece retain greater compressive residual stress and prevent the emergence of tensile residual stress. This work of the thesis provides a basis for the research of residual stress in UVG.