Investigating the tribological behavior of 18CrNiMo7-6 gear material in mining reducers under dust-contaminated lubrication

ZHAO Jiapeng; PANG Xinyu; MA Fuwen; HE Yixiang; LÜ Kaibo; ZHANG Zhandong

doi:10.16579/j.issn.1001.9669.2026.07.006

Abstract：[Objective]The lubrication environment of mining reducer gears is often contaminated by coal mine dust.The paper took the gear material 18CrNiMo7-6 as the research object and conducted friction tests.The tribological behavior of the gear material 18CrNiMo7-6 was investigated under dust-contaminated lubrication.[Methods]80 mesh pulverised coal particles,200 mesh pulverised coal particles,200 mesh silicon dioxide particles,and 200 mesh mixed particles of silicon dioxide with pulverised coal were selected as pollutants.The mass fractions were set at 0.5％,1.0％,and 3.0％.Friction and wear tests were conducted using the material surface property comprehensive tester.Friction coefficients and oil temperature changes under different lubrication environments were obtained.The wear mechanisms of the gear material were analyzed using the scanning electron microscope(SEM),confocal three-dimensional profilometer,and energy dispersive spectrometer(EDS).[Results]The results indicate that the pulverised coal particles in most pulverised coal test groups play a certain role in reducing friction,leading to a smooth wear surface.However,an exception is the test group featuring 80 mesh pulverised coal with a mass fraction of 3.0％.the pulverised coal particles in this test group trigger the adhesion effect on the contact surface,resulting in intensified adhesive wear.Silicon dioxide particles severely damage the oil film on the contact surface,thereby diminishing the anti-wear performance of lubricating oil.As the mass fraction of silicon dioxide particles in lubricating oil increases,abrasive wear intensifies.The pulverised coal particles in the 200 mesh mixed particle test group do not exhibit a friction-reducing effect,but instead exacerbate the lubrication environment.As the mass fraction of contaminants increases,the wear mechanism transitions from abrasive wear and fatigue wear to severe abrasive wear and severe adhesive wear.