TiN Particles Transfer onto Surface of Carburized Steels and Improvement in Seizure Resistance by Fine Particle Peening

Carburized steels were subjected to peening with fine titanium-nitride (TiN) particles under ambient conditions to transfer TiN particles onto the surface and improve their seizure resistance. The surface microstructures of carburized steels treated with fine particle peening using TiN particles (TiN-FPP) were characterized using electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Fine TiN particles were successfully transferred onto the carburized surface, but the thickness of TiN particles transferred layer depended on the nozzle distance and substrate hardness. Seizure resistance of the TiN-FPP treated steels was evaluated through SRV tests conducted under lubricant oil environment. TiN-FPP at shorter nozzle distance increased the mean time to failure (MTTF) of carburized steels due to the formation of a thick TiN particles transferred layer. In addition, the worn surfaces of both the substrate and counter materials were examined by EPMA to elucidate the mechanism of improving the seizure resistance by TiN-FPP.