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Information × Registration Number 0225U004584, (0124U003037) , R & D reports Title The effect of structural and chemical heterogeneity on wear resistance and propagation of fatigue cracks at the wheel-rail contact point popup.stage_title Дослідження особливостей зміни структури в зоні контакту пари колесо-рейка в залежності від величини навантаження та ковзання при коченні. Підготовка звіту. Написання звіту, публікація результатів Head Kononenko Hanna A., Доктор технічних наук Registration Date 13-12-2025 Organization Institute of Ferrous Metallurgy. ZI Nekrasov of the National Academy of Sciences of Ukraine popup.description1 Development of recommendations on the ratio and level of hardness in the wheel-rail contact based on the results of studies of structural changes during rolling wear and rolling-sliding to prevent the development of fatigue cracks and sudden failure during operation. popup.description2 The work establishes the regularities of wear of railway wheels and rails depending on the bulk hardness, structural state and manufacturing method. It is shown that the ratio of rail and wheel hardness Hr/Hw can be used only as a preliminary criterion, since the actual surface condition is determined by the accumulated plastic deformation, hardening during operation and structural changes under thermal influence during braking. Solid-rolled wheels demonstrate stable and lower total wear, while cast wheels under conditions of decreasing Hr/Hw are characterized by an uncontrolled increase in mass loss. The dependences of the specific wear rate (μg/m) on the specific shear energy effect (N/mm2) were obtained, which made it possible to assess the behavior of steels of different grades under conditions of light wear. It was found that high-strength steels of classes C, ERS8 and T have a lower wear rate compared to steels ER7, ER8 and grade 2. Microstructural analysis showed an increase in microhardness after wear tests at the limit depth of the rim due to riveting by strain accumulation. An integral coefficient of strengthening of the structure over the section was proposed, which allows us to estimate not only the degree of strengthening, but also the depth of deformation penetration from the contact surface. It was shown that the mass loss from hardness has a parabolic character for rails and a hyperbolic character for wheels, which is due to the difference in the structural state and the influence of the counter-body. The study formed an idea of the wear mechanisms and parameters of fatigue crack development, which is important for increasing the reliability of the wheel-rail pair. Product Description popup.authors Ganna A. Kononenko Safronova Olena A. Podolskyi Rostyslav V. popup.nrat_date 2025-12-13 Close