Tribological behaviour of Pearlitic and Bainitic steel grades under various sliding conditions

Railway systems have to cope with increasing and heavier traffic conditions. New rail steel grades are designed to extend rail life and to prevent rail defects. The tribological response of such steel grades under wheel–rail contact conditions needs to be studied before its use on real track. Tests on reduced-scale simulator, i.e. roller-on-plate tribometer with wheel–rail contact like conditions, have been performed on three rail steel grades: the Pearlitic, the heat-treated Pearlitic and the Bainitic. Results show a difference in both sensitivity and mechanism of particle detachment with the steel grade microstructure, but no difference in friction coefficient evolution.

► Particle detachment is maximum for coupled longitudinal and lateral sliding.
► Pearlitic steel grade is more sensitive to particle detachment than Bainitic.
► Steel grade microstructure strongly influence both particle size and birth mechanism.
► Friction coefficient evolution does not depend on rail steel grade.