Designing steel composition and microstructure to better resist degradation during wheel-rail contact

To reduce whole-life costs of the railway system (through increased asset life, reduced maintenance) and generate performance improvements (such as increased service availability and reliability), it is important to select the optimum material composition for railway components. Selecting the optimum materials for wheels and rails is a complex task with many conflicting requirements, including: a range of failures mechanisms, variety of operating and loading conditions and the associated financial implications. This research will establish a comprehensive scientific understanding of the metallurgical characteristics of rail and wheel steels to enable scientifically-informed choices. It will take account of both the specific requirements arising from the peculiarities of railway wheel-rail contact and the economic trade-offs at a system-wide level.
Recent development of 'High Performance' (HPRail) rail steel by Tata Steel has shown that improvements in the resistance to both wear and rolling contact fatigue (RCF) can be achieved through judicious choice of alloying elements to alter the microstructural characteristic of the steel. However, the understanding of reasons for the success of such steels requires further fundamental research to establish how the different constituents of steel microstructures react to the forces imposed at the wheel-rail interface. The results of such research will help establish the design rules to engineer steel microstructures that provide a step change in the resistance to key degradation mechanisms with greater predictability of the deterioration rates.
The project combines the skills of an interdisciplinary team from four Universities (based at the Universities of Huddersfield, Cambridge, Leeds and Cranfield), necessary to deal with the complexity of the phenomena,