New Rail Steels for the 21st Century

摘要

As the axle loads have been continuously increasing with time, so has the desire for premium rail steels with better wear, rolling contact fatigue and fracture. A research program has been initiated to study the microstructural aspects of near-eutectoid steels that would improve these properties. The first phase of the work was to carefully characterize the existing rail steels in terms of interlamellar spacing, cleanliness and pro-eutectoid cementite. These parameters were then correlated with both mechanical properties and overall rail performance. The second phase of the program was to develop a better microstructure through control of composition, thermomechanical processing and cooling path. The mechanical properties of these new steels have been determined and the rail performance tests are being conducted. This paper will report on both phases of this research program. Guidelines for future rail compositions and processing to obtain improved properties and performance will be presented.