电力金具材料表面热镀锌层的摩擦学性能研究OA

This study presents a comprehensive investigation of the tribological properties of hot-dip galvanized layers surfaces,focusing on enhancing the wear resistance of power fittings materials.Through hot-dip galvanizing,a galvanized layer with excellent metallurgical bonding is formed on the substrate surface.The research further explores the service life of the galvanized layer under different wear conditions.Q345R steel plates are selected as the substrate.Prior to the experiment,the substrates undergo alkaline cleaning for oil removal and acid washing for rust removal.Subsequently,the substrate is sequentially immersed in a flux solution(comprising 40%zinc chloride and ammonium chloride)and a molten zinc bath(with zinc purity of 99.99%).The galvanized layer is then solidified through water cooling.Friction and wear specimens are prepared using wire cutting and mounted on the worktable of an HT-1000 type ball-on-disk high-temperature wear tester.The specimens are paired with GCr15 steel balls to form the friction couple.The tribological performance of the galvanized layer is systematically investigated under varying wear time(900,1 800,2 700,2 600,and 4 500 seconds),wear loads(3,6,9,12,and 15 N),and rotational speeds(200,400,600,800,and 1 000 r/min).The wear loss before and after the friction and wear tests is measured with a precision electronic balance.The worn surfaces and grinding balls are analyzed by scanning electron microscopy(SEM)to observe their three-dimensional morphologies.Energy-dispersive spectroscopy(EDS)is employed to capture spectra at selected points,enabling elemental composition and content analysis.The results reveal that as wear time increases,the average friction coefficient exhibits a decreasing trend.The wear loss of the galvanized layer increases from 30.9 mg to 41.3 mg and stabilizes with minor fluctuations.The oxygen element content rises from 3.47%to 28.16%.The wear mechanisms evolve from abrasive and spalling fatigue wear to adhesive and oxidative wear.Under a 3 N wear load,the friction coefficient reaches as high as 0.67,while the material loss is minimal at 16.11 mg,indicating significant abrasive wear.With increasing wear load,the average friction coefficient decreases,but the wear loss increases,with adhesive wear becoming dominant.Analysis demonstrates that under lower rotational speeds,higher friction coefficients and lower wear losses are observed.Conversely,higher rotational speeds result in lower friction coefficients and higher wear losses.In both cases,severe adhesive wear occurs,and the zinc element content on the worn surfaces is relatively low.Under short-term,low-load,and medium-speed conditions,protrusions on the galvanized layer surface collide and detach first,scratching the worn surface to form micro-plowing grooves,thereby providing excellent protective effects for the power hardware.However,under long-term,high-load,and low/high-speed conditions,the contact area between the worn surface and the grinding ball increases,leading to easier lifting of the galvanized layer material,exacerbated material loss,and generation of significant heat,resulting in oxidative wear.Some material adheres to the surface,providing lubrication and protection,which reduces the average friction coefficient during the wear process.However,under low-speed conditions,severe adhesive wear still results in a relatively high average friction coefficient.