Reliability of railway wheels manufactured by various manufacturing methods (original) (raw)
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Metallurgicheskaya i gornorudnaya promyshlennost, 2019
Methodology. To identify the macrostructure of the metal of the wheels, deep hot etching was performed with a 50% aqueous hydrochloric acid solution according to GOST 10243. An assessment of the contamination of the metal of the wheels under study was performed in accordance with GOST 1778. The microstructure was detected by etching in 4% alcoholic nitric acid solution. Tensile tests of steel rims and wheel disks were carried out in accordance with GOST 1497, hardness according to GOST 9012, impact strength was determined according to GOST 9454. The results of mechanical tests were checked for compliance with the requirements of DSTU GOST 10791: 2016 Findings. The macro and microstructures of cast and solid-rolled railway wheels were studied. It was established that due to the characteristics of the production of cast railway wheels (the wheel rim crystallizes, feeding on liquid metal through a disk, then the disk and hub crystallize), all three zones that are observed in a steel in...
Scientific Approach to the Methods of Increasing the Life Cycle of Wheels of Railway Vehicles
Collection of scientific works of the State University of Infrastructure and Technologies series "Transport Systems and Technologies", 2021
The value of the life cycle of rolling stock wheels is determined by the frequency of maintenance, in the process of which the turning is carried out to restore the profiles of the rolling surfaces, or the replacement of completely worn wheels. Traffic safety depends on the technical condition of the wheels of locomotives and wagons. Maintenance and repair of wheelsets accounts for about 30% of all costs of Ukrzaliznytsia's rolling stock repair units. Wheel repair technologies are based on the complete restoration of wheel profiles by turning, using which, their life cycle is reduced, and costs increase by 20% or more. The railways of Ukraine use an outdated, unreasonable, inefficient system of control over the formation of rolling surfaces in operation. Therefore, there is a need to create a scientifically sound approach to methods of extending the life cycle of the wheels of locomotives and wagons while ensuring the safety of railway rolling stock. According to the proposed sc...
Innovation technologies in mechanical engineering ensuring life increase of railway wheels and rails
Science intensive technologies in mechanical engineering, 2019
In the paper it is shown that railway wheels and rails life depends considerably upon wear-resistance of their tread working surfaces. There is presented an innovation technology of a railway wheel tread electromechanical processing allowing the increase of its life. The innovation technology of railway wheel working tread electromechanical processing allowing its life increase is shown. The innovation technology for rail working tread allowing its life increase is given.
Condition of production and operation of railway sleepers from various materials
Forestry Engineering Journal
Sleepers are elements of the upper structure of the railway track. When choosing a material for the manufacture of sleepers, we are based on such basic factors as cost for the whole life cycle and performance characteristics. In connection with the depletion of wood stocks in the world and the short life of wooden sleepers, the process of using sleepers made of reinforced concrete, metal and plastic goes intensively. The service life of pine sleepers is no more than 12-15 years, reinforced concrete sleepers are about 30-50 years old, plastic ones are up to 40 years old, and metal ones are 50-60 years old. However, wooden sleepers differ in the least cost, they practically do not have restrictions on the laying areas, and in some cases have a clear advantage over other materials. Reinforced concrete, metal and plastic sleepers are more expensive than wooden ones, have a longer payback period and are recommended to be laid on roads with high freight intensity, where they can pay off a...
Method devised to improve technological reliability of machine parts
Eastern-European Journal of Enterprise Technologies, 2015
Проаналізовано причини відмов циліндрових втулок бурових помп. Розроблено метод вібраційно-відцентрового зміцнення для забезпечення надійності деталей типу «втулка». Адаптовано вібромашину об'ємного оброблення для поверхневого вібраційно-відцентрового зміцнення, приведено принципову схему установки та технологічне оснащення для його реалізації. Опрацьовано та проаналізовано профілограми віброзміцнених поверхонь. Намічено шляхи подальших досліджень Ключові слова: технологія, надійність, безвідмовність, циліндрова втулка, поверхневий шар, вібраційно-відцентрове зміцнення Проанализированы причины отказов цилиндровых втулок буровых насосов. Разработан метод вибрационно-центробежного упрочнения для обеспечения надежности деталей типа "втулка". Адаптирована вибромашина объемной обработки для поверхностного вибрационно-центробежного упрочнения, приведена принципиальная схема установки и технологическая оснастка для его реализации. Обработаны и проанализированы профилограммы виброупрочненных поверхностей. Намечены пути дальнейших исследований Ключевые слова: технология, надежность, безотказность, цилиндровая втулка, поверхностный слой, вибрационно-центробежное упрочнение
Fundamental and applied problems of ferrous metallurgy, 2020
Compliance with the new more stringent requirements for railway wheels is possible only with an integrated approach to improving their production technology with a reasonable choice of heat treatment modes, taking into account the chemical composition of steel. The purpose of the study is the experimental and analytical determination of the maximum permissible cooling rate of the rolling surface and the minimum required cooling rate of the central sections of the rim of a railway wheel to achieve a high level of hardness of the ferrite-pearlite structure. The studies were carried out on steels of grades ER8 and ER7 according to EN 13262, grade 2 according to GOST 10791: 2016, steel of class C according to AAR M-107 / M-208. Based on the hardenability test (GOST 5657) by the end hardening method (according to the Jomeni method), the distance from the surface from which one-sided cooling was performed, where the hardness met the requirements of the normative documentation for wheels m...
Determination and Analysis of Technical Parameters of the Bench for Railway Wheels Complex Tests
Science and Transport Progress. Bulletin of Dnipropetrovsk National University of Railway Transport, 2020
Purpose. The purpose of the work is to determine and analyze the technical parameters of the bench for railway wheels complex tests, providing for the combination of fatigue and contact strength tests, their simultaneous performing on same test-bench. Methodology. Determination of the technical parameters of the test-bench was carried out based on comparing the characteristics of fatigue and contact strength tests of railway wheels. Requirements for fatigue tests and related equipment are determined based on an analysis of the current regulations and patent review. A model of the contact strength test-bench with the introduction of necessary changes in terms of ensuring the cyclicity of the working effort application was adopted as the basic model for the development of a complex testbench. The criterion for the possibility of complex tests, involving the simultaneous testing of railway wheels for fatigue and contact strength, was the dependence of the test-bench roller diameter on the parameters of the tested wheel, the wheelset axle load, which includes the tested wheel and the wheel material endurance limit. Findings. The analysis of the obtained dependence showed that the roller diameter as a function of the load in the contact zone of the "wheelroller" pair has second order discontinuity in the section where this load changes from the minimum to the maximum value. Analytical dependence is also presented and analyzed in graphical form. The generalization of the results obtained made it possible to conclude that it is impossible to carry out complex tests of railway wheels, which provide for the combination of fatigue strength tests with contact strength tests, subject to their simultaneous holding at the same test-bench. Originality. For the proposed scheme of the bench for complex tests of railway wheels, for the first time, we obtained the dependence linking the parameters of the test wheel, the parameters of the bench, the wheel pair axle load and the wheel material endurance limit. Practical value. The results obtained can be used as a basis for the development of new test-benches for railway wheels.
Fundamental and applied problems of ferrous metallurgy, 2019
The analysis of normative and technical documentation is carried out, the characteristics influencing on wear resistance of railway rails are established, various modes of thermal treatment are considered. The results of measuring the hardness of the hot-rolled full-profile rail, made of steel, which is classified as steel of the K76F brand in accordance with the regulatory and technical documentation are given. The hardness of this rail corresponds to the strength class R260 or NT260 according to EN 13674: 1-2011 and GOST R 51685-2013 respectively, that is, from unalloyed steel without thermal hardening, intended for the production of turnouts and underground. On the basis of comparative analysis of various ways and modes of railway rail handling, further directions of increasing operational reliability are established by means of working out methods of heating, cooling. The microstructure of the experimental steel of the PCT after the furnace heating with cooling in various coolin...