Study on the Self-Organization of an Fe-Mn-C-B Coating during Friction with Surface-Active Lubricant

This paper investigates the friction process between an Fe-based coating and C45 steel with surface-active lubrication, as well as examines the coating surface before and after tribological testing. As a result, it is possible to determine whether the surface undergoes self-organization during friction. Coatings were produced by hardfacing a subeutectic alloy Fe-Mn-C-B modified by silicon, nickel, chromium and copper. Tribological tests were performed using a pin-on-disc tribometer. The pin (coating) and the disc made of steel C45 were subjected to heat treatment (hardening and tempering). The tests were carried out under loads of 3 MPa, 7 MPa and 10 MPa at a constant sliding velocity of 0.4 m/s and a sliding distance of 5700 m using a surface-active lubricant (glycerine oil). Obtained results were compared with the published results of previous tests carried out under the same conditions but under a load of 20 MPa. Obtained microscopic and spectroscopic results demonstrate that that the friction pair materials (the coating made of subeutectic alloy Fe-Mn-C-B modified by Si, Ni, Cr, Cu and C45 steel) and the surface-active lubricant cause self-organization during friction. The friction surface of the coatings has a flay-laminar structure and is covered with triboreaction products. The surface shows the presence of wear-resistant compounds such as oxides, carbides, borides and nitrides.