As an integral part the railway network infrastructure, insulated rail joints (IRJs) electrically isolate
track segments providing critical feedback to both track signaling and train position detection
systems. Because of the discontinuous nature of IRJs, accumulated damage at the railhead is high.
Failure modes include plastic flow of metal across joints, bolt and fishplate failures, delamination of
insulated material and, as a result of rolling contact fatigue, end post and endpost surface damage.
In the current investigation, microstructural changes in the vicinity of endposts of IRJs made from
both surface coated and uncoated rail are investigated using techniques of optical and scanning
electron microscopy. Damaged IRJs made from pearlitic head hardened rail steel are compared with
head hardened rail steel laser coated with martensitic stainless steel, the latter having an increased
service life. Problems associated with the surface coating are identified and approaches to further
improving IRJ resistance to rolling contact fatigue suggested.