Technology Digests / Investigation of Wheel-Rail Rolling Contact Fatigue Using Lubricating Media

TD22-001

March 1, 2022
Authors
  • Ananyo Banerjee
  • Yuqing Zeng
  • Daniel Thielemier
  • Ulrich Spangenberg
  • Xinggao Shu
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Key Findings

  • Compared to dry contact conditions, use of a third body layer of water and solid lubricants decreased wheel/rail wear by 50 to 70 percent.
  • Under metallurgical examination, RCF cracks were significantly longer and deeper in the rail due to application of water compared to the dry rail despite a lower traction ratio. The difference in RCF crack characteristics is thought to be the result of a combination of a much slower wear rate and hydraulic action of water at the crack tips.
  • Compared to the dry condition, lubrication slowed the wear rate, which led to longer dwelling time for the surface cracks to experience more wheel loads before wearing away. However, the solid lubricant seemed to slow down the crack growth in the used rail but had no significant effect on the new rail. The influence of lubricants on crack growth needs to be further investigated.

Investigation of Wheel-Rail Rolling Contact Fatigue Using Lubricating Media

MxV Rail (formerly TTCI) has conducted a series of full-scale wheel-rail (W/R) rolling contact tests by using the Rolling Contact Fatigue Simulator (RCFS)1 to investigate the effects of lubricating media (water and solid lubricant) on rolling contact fatigue (RCF) and wear with controlled traction ratios. The study showed that measured rail wear depths were substantial compared to RCF crack depths. Lubrication slowed the wear rate, which led to longer dwelling time for the surface cracks to experience more wheel loads before wearing away. Wheel-rail wear decreased by 50-70 percent compared to dry contact conditions due to the effect of water and solid lubricants. This research was jointly funded by the Federal Railroad Administration (FRA) and the Association of American Railroads’ (AAR) Strategic Research Initiatives (SRI) program. Effects of lubrication (lubricating greases, top-of-rail friction modifiers and water on rail wear) and surface damage of rails and wheels have been studied extensively…