Correlation between laboratory ball-on-disk and full-scale rail performance tests

Railroads in the United States spend approximately $2.5 billion a year on rail replacement and repairs, making rail the most valuable asset for the railroad industry in North America. The Transportation Technology Centre, Inc. (TTCI) continuously conducts full-scale rail performance tests using the newest generations of premium rails. This in turn allows better understanding of the rail characteristics that require improvements and is used to extend railʹs life. Recent research has focused on methods to streamline the developments of prototype rail steels using laboratory tribotests. The results of the tribotests indicate that sliding ball-on-disk experiments can be used to qualitatively approximate rail wear and using scanning electron microscopy (SEM) it is possible to observe different tribological behaviour between rails (mild to severe wear). For instance, SEM micrograph analysis can lead to the determination of the propensity of rail crack formation under pure sliding and the detrimental effects of pro-eutectoid cementite and hard inclusions (e.g., Al2O3) on crack formation and delamination.