Microstructure and tribological properties of complex nitrocarburized steel

Two kinds of tribological apparatus were employed to investigate the fricti on and wear performance of steel 1045 treated by quenching plus tempering a nd complex nitrocarburizing processes. The microstructures, phase identific ation, surface hardness and hardness profiles of the specimens were analyze d by optical metallography, microhardness tests and X-ray diffraction; at t he same time the surface roughness of specimen surfaces was tested using a profilometer. The experimental results show that: the E-phase formed on the specimen surface has a significant effect on reducing the friction coeffic ient and improving wear resistance; the oxidation after nitrocarburizing ra rely changes the friction coefficient but decreases the wear resistance. an d with oxidation plus polishing and secondary oxidation complex treatments being performed, the wear resistance of nitrocarburized specimens is improv ed even further. (C) 2000 Published by Elsevier Science S.A. All rights res erved.