Tribological Behavior of Wheel–Rail Contact Under Different Contaminants Using Pin-On-Disk Methodology

The objective of this study was to investigate the influence of contaminants on the tribological behavior of wheel–rail contact. Sand, phosphate, sulfur, and cement were the studied contaminants identified after a Tunisian railway expertise. All friction tests under different contaminants were conducted using pin-on-disk machine, maintaining the same sliding velocity and Hertzian pressure, respectively, at 0.1 m/s and 1000 MPa. All results were compared with reference of two configuration contacts: wheel tread-rail head (clean dry condition) and wheel flange-rail gauge (clean lubricated condition). The main findings of this study could be listed as follows. First, with reference to clean and dry condition tests, sand and cement showed a higher adhesion than phosphate and sulfur. Second, all contaminants increased the adhesion coefficient with reference to clean and lubricated conditions. Third, sulfur generated the lowest energy-wear coefficient yielding a mild wear. Fourth, sand, cement, and phosphate generated a higher energy-wear coefficient yielding an abrasive wear. Finally, the highest energy-wear coefficient was obtained with sand.