On the results of tribological studies of railway rails

Metal resistance to the formation of contact fatigue defects and wear development has a great influence on the consumer properties of rails. The most significant factors limiting the service life of rails in curved sections of the railway track are wear of rails of the outer threads and development of contact fatigue defects in the inner threads of the track. In this regard, methods of reliable laboratory assessment of the rail metal resistance become important in the development of new products. The paper describes the change in the nature of damage to rails of various hardness categories by contact fatigue defects, and evaluates their wear resistance. The study of defects and forecasting of the rail resource require an integrated approach. The paper provides a brief description of modeling the conditions of formation and accumulation of contact fatigue defects. The parameters under consideration have an effect on the wear resistance of rail metal of various chemical compositions. During the testing, the rails microstructure and the nature of crack growth change. The authors made a comparative analysis of the data obtained characterizing the wear resistance of rail steels of various hardness categories. The basis of the methodology for assessing the wear resistance of railway rails is the physical modeling of adhesion-deformation mechanism of friction of the samples on a roller friction machine (tribometer). During laboratory tests of the studied categories of rails, the friction machine automatically outputs and records a number of computational parameters shown in the work. The conducted research is promising from a practical point of view. The results obtained can be used to develop a theory to increase the service life of differentially hardened rails produced by JSC EVRAZ United West Siberian Metallurgical Plant.