Phased array inspection of aluminothermic rail welds The automated solution A fast convenient means of inspecting rail joints arrives

摘要

There are millions of aluminothermic welds made each year to join rail in Europe's rail network and millions are already in-service. Occasionally flaws develop during and shortly after welding that can lead to early failure and this can cause disruption to train services and costs to both the train operating companies and the maintenance operators. Although radiographic inspection is sometimes carried out, this is not very common, and the conventional ultrasonic standard requires many probes and scans because of the complex geometry. Since the welds are made by a casting process, these can be more difficult to inspect than joints made by other welding processes. Hence, the RAILECT project was conceived to provide a convenient means of inspecting the joints using a multiple phased array ultrasonic system. This article describes the type of flaws concerned, the modelling of the ultrasonics, the practical realisation of a prototype system and the development of acceptance criteria.