INVESTIGATION OF THE APPLICATION OF AUSTENITIC FILLER METALS IN PAVED TRACKS FOR THE REPAIR OF THE RUNNING SURFACE DEFECTS OF RAILS CONSIDERING FIELD TESTS

Abstract

The current study aims to define a welding technology that allows for the repair of normal and heat-treated rails in paved tracks with partial dismantling and partial preheating in such a way that the resulting layer is not susceptible to cracking and can be done with minimal dismantling, even during night shifts or while traffic is present. High-elongation austenitic consumables (capable of approximately 2-3 times greater elongation than rails; rails have approximately 8-14% elongation) were used and tested for this purpose. Welds and rail tread defects were repaired on Hungary's busiest tram line (12-14 million gross tons per year), which also has a high axle load compared to other European tram lines. The repairs were performed on various rail grades using different layer numbers, and the experimental consumables were compared to conventional hardfacing welding methods. Welds were continuously monitored after welding, and surface hardness measurements were taken. A hardening function and an applicable technology were defined based on the results. The function compares the through-rolled axle tons to the expected hardness values over the first 6 million tons. Partial preheating and partial track disassembly can be used to weld a layer of hardness equal to the hardness of the rails and wheels.