A Perspectival Review of Rail Behavior at the Facility for Accelerated Service Testing

摘要

The rail metallurgy tests which have been undertaken at the Facility for Accelerated Service Testing (FAST) are described. The best of the premium metallurgies has been found to wear approximately three to four times better than standard rail in the unlubricated regime. In the lubricated regime, however, the maximum improvement in wear rate achievable by the use of a premium rail has been found to be only 50%. A strong effect of equivalent carbon has been observed for standard (Std) and high silicon (HiSi) rail in the unlubricated regime. Reduced wear and metal flow have allowed increased rail fatigue failure. When allowances are made for difference in wheel load, failure rate of Std rail at FAST is consistent with failure behavior of Std rail in U.S. railroad service. Growth of a transverse crack in the head of a rail is shown to be consistent with predictions made from simple linear elastic fracture mechanics considerations where the flexural stresses are augmented by the curving action of the train and substantial axial residual tensile stresses are assumed to exist under the work hardened running surface region of the rail head.