Study on Correlation Between Surface Physical Characteristics and Wear Mechanism of Carbon Strip of the Pantograph-Catenary System at a Speed of 300 km/h

Abstract As a critical component of the pantograph-catenary system, the surface physical characteristics of the carbon strip directly affect the wear mechanism of the friction pair and the current-carrying stability. In this study, a ring-on-block high-speed current-carrying tester was employed to investigate the correlation between the surface physical characteristics of the carbon strip (surface roughness) and its wear mechanisms under a sliding speed of 300 km/h, a current of 300 A, different normal loads, and varying test durations. The evolution of surface roughness was analyzed using white light interferometry (WLI). The results indicate that the surface roughness of carbon strips varies with both increasing normal load and prolonged test duration. Furthermore, the surface roughness of the carbon strips shows a negative correlation with current-carrying efficiency and a positive correlation with the wear-rate. Scanning electron microscopy (SEM) analysis reveals that the wear mechanism of the carbon strip varies under different loads. Notably, nodular protrusions appear on the surface of the carbon strip under low normal loads, which are formed by material transfer from the contact wire. Due to their high hardness, they significantly increase the friction coefficient and surface roughness of the carbon strip. The suppression of arc erosion pits and nodular protrusions can effectively improve the contact state of the friction pair, thereby enhancing the current-carrying efficiency of the pantograph-catenary system and the operational stability of the train.