The wear behaviour of duplex treated AISI 5140 steel

Purpose - This work aims to investigate the wear behavior of manganese phosphate coating on plasma nitrided AISI 5140 steel. Design/methodology/approach - Prior to manganese phosphate coating, plasma nitriding of substrates was performed at gas mixture of 50 percent H-2 and 50 percent N-2, for the different treatment parameters. The structural, mechanical and tribological properties of the substrates were determined using hardness test, optical microscope, scanning electron microscopy, X-ray diffraction and pin-on-disk tribotester. The wear behavior of untreated, nitrided and duplex treated substrates was evaluated under dry sliding conditions. Findings - The results indicated that the duplex treatment improved the wear behavior. It was also observed that manganese phosphating of the nitrided substrates at low temperature (450 degrees C-2h-N) resulted in a decrease of the wear rate and yielded a reduction in the friction coefficient by forming a transfer film at the counter face. Originality/value - This study can be a practical reference and offers insight into the effects of duplex treating on the increase of wear resistance.