A new multi-scratching approach to identify the interaction between grit size and surface roughness on the residual stresses during belt-finishing

Abstract

The present work investigates the effect of the abrasive grain size and its correlation with the surface roughness during belt-finishing processes of AISI 52100 steel alloy. The belt-finishing operation can be described by the movement of many abrasive grains rubbing the workpiece's surface at the same time. To investigate qualitatively the influence of the grit size and the repetitive passage of abrasive grains on the distribution of the residual stresses, a new multi-abrasive grains approach, based on two-dimensional finite element modeling of progressive scratchings on rough hard-turned profile, is carried out. A theoretical approach is developed to quantify the penetration depth's evolution for every scratching due to the AISI 52100 steel's elastoplastic behavior. The numerical results reveal that, during repeated scratchings on smooth or rough hard-turned surface, increasing the size of the abrasive grains tends to stabilize, quickly, the residual stresses in the interface and to improve the distribution of the compressive residual stresses along the depth. While the smoother is the initial surface, the better is the residual stress field. Moreover, it appears that the residual stresses in the skin and the sub-layer become more compressive, mostly during the additional repeated scratchings on a stabilized scratched surface, which is due to the strain-hardening phenomenon related to the progressive passage of the abrasive grains. These findings are then used to extract simple empirical laws and suggest an efficient way to improve the residual stress field that occurs during abrasive superfinishing processes.