Enhancing tribological properties of 18CrNiMo7-6 through grain refinement incorporating Al2O3 particles

Abstract

Wind turbine gears are critical components within the internal gearbox of the wind turbines. However, the vulnerability of gears to wear adversely affects their operational lifespan. Here, we propose a novel approach utilizing ultrasonic shot peening to incorporate Al2O3 particles onto the surface of the 18CrNiMo7–6, termed the USG treatment. The tribological test shows that the coefficient of friction and wear rate of the USG-treated sample decreased by 14.4% and 58.3% respectively, as compared to the untreated sample. Experiments and detailed analysis reveal that 18CrNiMo7–6 not only undergoes grain refinement on its surface but also forms a wear-resistant layer enriched with Al2O3. The findings here provide a new insight into the design of wear-resistant layers on gear steel surfaces.