Study On The Arc Erosion Characteristics Of Pantograph Strip Materials

With the rapid development of heavy-load railway and high-speed railway in China,the load current of traction power supply system doubles and the train speed increases gradually,leading to the frequent occurrence of pantograph arc.The intense erosion effect caused by arc discharge induces the serious loss of strip materials and shortens their lifespan severely,which has become a critical threat to their service life and working reliability.Nowadays,the influence of arc on strip materials is studied mostly based on the sliding test,and the most attention was paid to the effect of arc energy or contact loss rate on the wear and friction properties of strip materials.However,the arc characteristic itself and the arc erosion characteristic of strip materials are still in absence.Therefore,it is necessary to carry out the systematic research on the arc erosion characteristics of strip materials,which will be meaningful to understand the degradation effect of arc on strip materials and find effective measures to decrease the erosion degree from the perspective of material improvement.In this paper,the interaction process between arc and strip materials is divided into two stages.The first is the generation of arc discharge on the strip surface,and the second is the arc erosion of the strip materials.Aiming at the first stage,the arcing mechanisms of three strip materials were studied respectively,and the main particle compositions participating in the arcing process were diagnosed.The mechanism of the ingredient and microstructure of different strip materials on the arcing process was clarified.Meanwhile,the temperatures of arc with different pantograph materials were calculated,and the positive correlation between arc temperature and the content of metal composition in strip materials was found.For the arc erosion stage of the strip materials,the relation between the mass loss of strip after arc erosion and the quantity of electric charge was studied,and the erosion rate was defined as well.The erosion rates of pure carbon materials,copper-base powder metallurgy materials,and copper-impregnated carbon materials were 0.00814 mg·C^-1,0.0112 mg·C^-1,and0.04395 mg·C^-1,and the pure carbon materials has the best arc resistance property.Meanwhile,after arc erosion,the macroscopic morphology characteristics and phase composition of strip materials were analyzed.The physicochemical reactions and temperature evolution of strip materials during the arc erosion process were discussed.Based on this,the arc erosion mechanisms of three strip materials were clarified,and finally,the measures that may improve the arc erosion resistance of different strip materials were put forward too.