Microstructure and properties of the new bainitic rail steels

The demand on the performance of rail on the railway track is much more for the speed and the load of the passing trains is much higher. Head hardening treatment on rail is an economical and effective way of prolonging the service life of rail by improving the rail's mechanical properties. The microstructure and properties of the bainitic cast steel for scissors crossovers. Here is to use rail materials of greater strength that accordingly have a higher resistance to rolling contact fatigue (RCF). It has been investigating the suitability of bainitic rail steels for use on lines with rolling contact fatigue problems with the aim of cutting track maintenance input without increasing the level of vehicle maintenance due to increased wheel wear. The present findings indicate that, as well as reducing wear, higher-strength bainitic grades also result in shallower head checks, enabling them to at least delay the attendant damage done to the rail. Furthermore, non heat-treated, naturally hard steels could well be developed as an alternative to the head-hardened rail, especially since the wear at weld joints to which head-hardened rails are subject would cease to exist. Bainitic rail steels may produce a balance between the processes of wear and rolling contact fatigue at a low level. However, minimum strength needs to be observed when using them, though, due to the altered wear mechanisms of bainitic steels. Advanced rail steels with both pearlitic and bainitic microstructure and hardness up to 56 HRC with the aim to meet nowadays demands of railroads for components with longer service life time and reduced needs for maintenance at the same time.