The aim of the present paper is to investigate the residual stress distribution generated in surface layers by machining. Experiments revealed that an increase of residual stress value in tensile zone (546 MPa) is connected with a high value of carbon percentage for up to 0.9 % from surface layer, while the decrease of residual stress value from approximately 550 to 300 MPa corresponded to a level 0.6 % of carbon. A theoretical investigation based on a finite element model (FEM) was carried out in order to check the influence of the carbon content on the residual stress distribution. Six types of materials containing various amounts of carbon (from 0.4 % C up to 0.96 % C) but with constant content for the other alloying elements were used in the simulations. The cutting parameters were kept constant in order to assess the influence of carbon presence over residual stress. From the FEM simulation a correlation between the carbon percentage and the distribution of the residual stresses in the surface layer was observed.
