Residual stresses induced by machining of a plain carbon steel using coated and uncoated commercial tungsten carbide tools

It is well known that machining results in residual stresses in the workpiece. These stresses correlate very closely with the cutting parameters (cutting tool geometry and material, work material, and machining regime). This paper concentrates on the residual stress induced by turning of AISI 1045 steel. Particular attention is paid to the influence of the cutting speed and tool material. In experiments, the residual stresses have been measured using the X-ray diffraction technique (at the surface of the workpiece and in depth). Special attention was paid to the influence of the coating applied to the carbide inserts on the residual stresses due to machining. These residual stresses were analyzed accounting for the thermal and mechanical phenomena during machining. The temperature distribution on the tool and chip has been determined experimentally using specially designed infrared equipment installed on the lathe. Three orthogonal components (F_c, F_f and F_p) of the cutting force were measured using a piezoelectric dynamometer. For the range of cutting parameters used in the machining tests, the results show that the coated tool produce the tensile residual stresses, which are critical in the performance of the machined components.