Friction and wear behaviors of surface nanocrystalline layer prepared on medium manganese surfacing layer under oil lubrication

• A nanostructured layer is formed on the surfacing layer by means of PFRT.
• The ability of bearing oil-lubricated film and contact-fatigue resistance are improved.
• The wear mechanics of PFRTed sample is abrasive wear instead of abrasive wear and fatigue wear.
• Grain refinement results in high surface hardness and surface activity.
• The compressive stress and nanocrystalline layer have beneficial effect on fatigue resistance.

A nanocrystalline surface layer was fabricated on a medium manganese surfacing layer by rolling technology. The tribological behavior of the nanocrystalline layer was investigated under oil lubrication. The thickness of the nanocrystalline layer is 10 μm. Experimental results show that the friction coefficient and wear volume are reduced by 10% and 80%, respectively. After surface nanocrystallization, there occurs a transition from the combined action of abrasive wear and fatigue wear to the abrasive wear. The advantages realized in the tribology properties of the treated sample may be attributed to the enhancement of the hardness and the surface residual compressive stress and homogeneous oil-lubricated film.