Characteristics of Rb40 steel superficial layer under ball and roller burnishing

Both ball and roller burnishing processes are largely considered in industrial cases in order to ameliorate surface characteristics. Usually, roughness and hardness are sought to measure surface integrity. The aim of this study is to develop a device for mechanical plastic deformation of structural Rb40 steel using ball and roller burnishing and to investigate the evolution of associated roughness, hardness and wear resistance. It was found that roller burnishing provides optimal roughness results, particularly when initial surface quality is close to 3 μm whereas in terms of hardness, ball burnishing becomes interesting. Optimum roughness and hardness are obtained for a specific operating regime in which decisive parameters are the applied force as well as the number of passes. When considering roughness criterion, it is recommended to limit the number of passes to two while three passes are advised for a hardness basis. Rb40 steel superficial layers treated by either roller or ball burnishing behave as a grinded surface with an appreciable wear resistance.