Wheel-rail system life cycle optimization
Objective: To discuss the issue of ensuring the reliability of rolling stock elements by analyzing the wheel-rail ratio. To show the influence of the wheel and rail metal hardness on their wear. To offer a wheelset of increased hardness. Methods: The system, structural and functional, and comparative analysis approaches have been used. Results: The possibility to increase the wheelset hardness by using grade 4 steel has been indicated. At the same time, a 150% increase in the life of the proposed wheelset has been noted. The service life of rails of increased hardness has been compared with the standard. The annual costs for wheelset repair and for rail replacement have been calculated, and the cash savings determined. It has been noted that, in addition to the use of grade 4 steel, according to GOST 398-2010, it is possible to increase the hardness of a wheelset by using hypereutectoid steels with fine cementite particles (which have greater plasticity and hardenability due to the high content of austenite in the structure and have a more uniform distribution of hardness over the section) or by creating an intense-hardness surfacing of the above mentioned steels on the rolling surface of the wheelset. Practical importance: Using wheelsets of increased hardness, namely, made of grade 4 steel according to GOST 398-2010, it is possible to extend the wheelset life cycle to 15,25 years and achieve annual cash savings of 6,11 billion rubles. The disadvantages of this solution are a decrease in the service life of the rails and an increased track time for their replacement, which will negatively affect the service speed. However, a decrease in the wheelset flange wear will lead to a decrease in the number of train delays due to uncoupling of technically faulty cars from the train, which will increase the service speed that determines the quality of operation.