Experimental study on the influence of slip ratio on irregular wear behaviors of wheel/rail

Abstract

This study aimed at investigating the effect of slip ratio on the wheel-rail polygonal wear using a twin-disc machine. The slip ratio used in the test included 0.91%, 3.83%, 4.55% and 9.43%. The profile of samples, vibration, wear and damages were analyzed. Through establishing the relationship between speed, frequency and slip ratio, the conditions for generating apparent polygons were analyzed. The results indicate that under the lower slip ratio, the wheel-rail system has no obvious main vibration during the wear process and is not easy to generate polygon wear. With the increase in the slip ratio, the wheel-rail system easily excites some polygonal characteristic frequency during the wear process. When the characteristic frequency is excited and the frequency amplitude increases continuously, the sample produces obvious polygon wear of corresponding order. When the characteristic frequency is excited but the amplitude of frequency is low, the sample will easily produce slight polygon wear. In addition, when obvious polygonal wear is generated, the damage form at the crest is rolling contact fatigue wear and a small amount of peeling pits, and the damage form at the trough is the severe peeling. Meanwhile, the hardness and plastic deformation layer thickness in the crest region is lower than in the trough region.