Technology Digests / FAST® High Strength Rail Test: Rolling Contact Fatigue and Grinding Analysis

TD22-030

November 1, 2022
Authors
  • Kenny Morrison
  • Ryan Alishio
  • Ananyo Banerjee
  • Anish Poudel
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Key Findings

  • The high rail vertical wear rate between 451 MGT (after second grind) and 555 MGT (before third grind) was faster compared to the vertical wear rate between 212 MGT and 371 MGT.
  • Crack depths measured by EMFI showed a higher overall decrease between 430 and 530 MGT compared to the decrease between 212 and 370 MGT, which can be attributed to differences in vertical wear rates leading to lower dwell time for cracks to grow.
  • Visual RCF assessment and EMFI crack depth measurements had different trends. Surface conditions looked worse for some rails after grinding even though the overall crack depths measured at the subsurface decreased.

FAST® High Strength Rail Test: Rolling Contact Fatigue and Grinding Analysis

Since 2018, MxV Rail (formerly TTCI) has been testing and evaluating the performance of eight premium rail types (also known as high strength, or HS, rail) with no direct lubrication on a 5-degree reverse curve at the Facility for Accelerated Service Testing (FAST®), Pueblo, CO. Grinding has been conducted three times with rolling contact fatigue (RCF) damage evaluated both visually and using electromagnetic field imaging (EMFI) nondestructive evaluation (NDE) techniques before and after each grinding sequence. This Technology Digest focuses on the conditions of the high rail in the test curve, and a future edition will discuss the low rail. BACKGROUND Two previously published editions of Technology Digest 1,2 summarized the wear performance results of the FAST® testing through 325 million gross tons (MGT), and the participating rail types’ initial mechanical and metallurgical test results. MxV Rail engineers estimated visually the RCF above each tie on each rail for the…