Laboratory study of the rolling contact fatigue of high manganese steel crossings

Rolling contact fatigue (RCF) is an important mechanical parameter for railway crossings, and it is, in particular, of significance to understand the RCF characteristics of the crossings under actual service conditions. This article investigated the RCF behavior of high manganese steel crossings by in-laboratory simulating the actual service process of the crossings under a condition of pure rolling contact fatigue using a self-made RCF device. The results indicated that under the laboratory condition the depth of the hardened layer in the surface of the high manganese steel crossings was about 2 mm, and the maximum hardness value on the surface reached about 700 HV; the rolling contact fatigue cracks were formed on the surface of the sample. In comparison, in the high manganese steel crossings subjected to actual railway service, fatigue cracks were formed at a depth of about 2 similar to 3 mm below the surface, the hardened layer was measured to be about 10 mm and the maximum surface hardness value was about 530 HV. It is suggested that the failure of actual high manganese steel crossings is not caused by pure rolling contact fatigue only; but rather, the fatigue failure process might be promoted largely by the impact effect of running wheels.