Influence of Rail Surface Roughness Formed by Rail Grinding on Rolling Contact Fatigue

Abstract

In this article, authors analyze the effects of initial rail surface roughness on the speed of onset for rail rolling contact fatigue (RCF) due to friction. A twin-disk rolling contact machine was used to analyze a number of perspectives such as surface roughness, plastic flow, hardness, and axis density of crystals. Rail roughness often occurs as a side-effect of preventative rail grinding implemented to reduce preexistent rail RCF or to correct longitudinal rail surface irregularities like corrugations and welds. Crystal axis density was determined by using x-ray diffraction of inverse pole figure measurement in order to examine the level of RCF that rails were experiencing. Researchers found that initial rail roughness was quickly mitigated by repetitive loading cycle. Using the three analytic methods previously mentioned, researchers determined that initial rail roughness did not further contribute to rail RCF.