Abstract:This paper compares the tribological behaviour of microalloyed rail steel with conventional C-Mn rail steel under different test conditions (load, temperature and humidity). Pin-on-disc tribological tests were performed inside a climate chamber under different loads (20, 30 and 40 N), relative humidity (15, 55 and 70% RH) and temperatures (20 ºC and 40 ºC). After friction and wear tests, worn surfaces were analysed using both confocal and scanning electron microscopy. The results obtained show that the use of microalloyed steel in railway applications under severe conditions (high loads and humidity) could lead to an increased service life for the rail and extend the time between maintenance operations.http://mc.manuscriptcentral.com/JRRT Journal of Rail and Rapid Transit