Study of Melting Methods by Electric Resistance Welding of Rails

An analysis of the results of rail operation shows that up to a third of all rail breaks in the railway line and up to 12.9% of all withdrawn acute defective rails are associated with welded joints. This is largely explained by the formation of structures with martensite sections in the welded joints of rails and the formation of burns. This work presents the results of studying welded joints, obtained under three welding modes (continuous flash welding, pulsating flash welding and combined flash welding). The conducted studies have shown that the flash welding mode significantly influences both the cooling rate value and the very nature of the thermal cycle of the welded joint as a whole. Changes in the cooling rate under different modes exert a significant influence on the structure and properties of the weld. Resistance welding of rails from the steel grade E76HGF by pulsating flash welding can result in the appearance of needle martensite areas, which is the reason for increased embrittlement of the weld and a decrease in its properties. The conducted field experiments have reliably shown that in the conditions of the combined welding mode it becomes possible to avoid these problems. Moreover, a slight increase in the mechanical properties of the weld in the range of 2–4% has been experimentally recorded, and the destructive load of the welded joint of the rail increases by 2–3% at high values of the bending deflection. In turn, these factors allow a significant reduction in the number of cases of rail welded-joint failures in real conditions of their operation

The Parallel Genetic Algorithm for Construction of Technological Objects Neural Network Models

The parallel genetic algorithms implementation for neural networks models construction is discussed. The modification of this global optimization algorithm is proposed. The artificial neural networks are effective instrument to solve most problems of technological objectives and processes modelling. The article describes the aspects of genetic algorithms implementation for neural networks structure-parametric synthesis. It is offered to use different parallelization technique of genetic algorithm to increase computing performance. It is proposed to modify the standard multipopular parallel genetic algorithm adding its base topology dynamic adaptation. This approach allows to make effective algorithm with minimal computational difficulty. The algorithm modification shows best results, when implemented in computer network

The Parallel Genetic Algorithm for Construction of Technological Objects Neural Network Models

The parallel genetic algorithms implementation for neural networks models construction is discussed. The modification of this global optimization algorithm is proposed. The artificial neural networks are effective instrument to solve most problems of technological objectives and processes modelling. The article describes the aspects of genetic algorithms implementation for neural networks structure-parametric synthesis. It is offered to use different parallelization technique of genetic algorithm to increase computing performance. It is proposed to modify the standard multipopular parallel genetic algorithm adding its base topology dynamic adaptation. This approach allows to make effective algorithm with minimal computational difficulty. The algorithm modification shows best results, when implemented in computer network

Review of Methods for Improving the Energy Efficiency of Electrified Ground Transport by Optimizing Battery Consumption

The article reviews the existing methods of increasing the energy efficiency of electric transport by analyzing and studying the methods of increasing the energy storage resource. It is grouped according to methods, approaches, and solutions. The most effective methods and ways of their implementation are identified. General methods of increasing energy efficiency, methods of increasing recuperation during braking, methods of energy-efficient energy consumption, the use of energy-saving technologies, and improving the energy efficiency of the traction drive are considered. The purpose of this work is to identify the main operating factors on the basis of a critical review of existing methods for assessing the technical condition of batteries and experimental results on the degradation of lithium-ion batteries. Using the great experience of the research group in the field of modeling, diagnostics, and forecasting of life of electric cars, as well as their intellectual management, the new theoretical and practical methods of integrated assessment of the parameters of the traction battery and state of charge, which are operated in the heavy forced regenerative regimes of electric traction, are created and proposed. A great role is played by the construction of the transport model. The development is based on physical laws that passengers and vehicle owners are unaware of. For each model there is a different area of application, and what is suitable for one object may not be suitable for another. The overview shows that there is no one-size-fits-all way to improve energy efficiency. It is necessary to make a choice among several proposed models after a thorough feasibility study

Algorithm for managing investment resources for enterprises' fixed assets reproduction

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X-ray Diffraction Phase Analysis of Changes in the Lattice of Pervouralsk Quartzite upon Heating

At present, quartzite is widely used across many industries. The properties of quartzite significantly affect the technology used during the preparation of the raw materials as well as the technology used for manufacturing the final product, which may be intended for further operation at different temperatures. The purpose of the study was to create a scheme for the transformation of quartzite that would describe the changes in the parameters of its lattice parameter upon heating and would offer guidance regarding the drying technology and technology required to obtain tridymite. A Bruker D8 Advance diffractometer was used to study changes in the phase composition of quartzite at the temperatures of 200, 400, 600, 879, 1000, 1200, 1470, and 1550 °C. A detailed scheme of transformations of PKMVI-1 quartzite with a SiO2 content of at least 97.5% at normal pressure was proposed for crystalline modifications formed during its heating. As a result of this research, the changes in the parameters of the lattice parameter—such as the average interplanar distance davg, the volume of the unit cell Vavg, the density of the unit cell Davg, and the molecular weight Mavg—were established

The Technology of Using Liquid Glass Mixture Waste for Reducing the Harmful Environmental Impact

The spent liquid glass mixture, which is widely used in foundries as a binder after knocking out of moldings, contains pieces of different sizes and strengths, and there is a strong silicate film on the sand grains themselves. The proposed regeneration plants, which provide for the removal of the silicate film by scrubbing, have low productivity and lead to abrasion of the grains themselves. For this reason, the knocked-out mixture is taken to the dump. As a result of the study of the state of the spent liquid glass mixture in the dump, it was found that, in the spent mixture that had lain for 8–10 years, under prolonged exposure to atmospheric precipitation at plus and minus temperatures, part of the silicate film dissolves and almost all monolithic pieces are destroyed. Further use of hydraulic regeneration allows us to reduce the film thickness and thereby reduce the percentage of liquid glass from 5–5.5% to 0.8–1.2%. This made it possible to select the composition of the molding sand for an automatic line, using the AlpHaset-process, which consists of 22–29% of liquid glass mixture from a dump, 65–72% of liquid glass, 5.5% of liquid glass, and a hardener in the amount of 0.55%

Increasing the Efficiency of Foundry Production by Changing the Technology of Pretreatment with Quartzite

The efficiency of the production of foundry products depends on the reliable operation of the melting furnace including, therefore, the durability of its lining. The most common material adopted for the production of an acid furnace crucible lining is quartzite, in which during the pretreatment (heating to 800 °C followed by holding), a tridymite phase appears that maintains a constant volume at 840–1470 °C for a long time and provides high lining durability of 300–350 melts, but only when using melting temperature regimes not exceeding 1500 °C. However, the absence of iron scrap leads to the smelting of synthetic iron from only one steel scrap using higher melting temperatures (1550–1570 °C), which sharply reduces the lifetime of the lining to 220 melts. This work is devoted to research aimed at establishing technology for the pretreatment with the original quartzite, which ensures the formation of a phase state that successfully withstands elevated temperatures for a long time. The studies were carried out using a Bruker D8 ADVANCE diffractometer and a Shimadzu XRF-1800 X-ray wave-dispersive spectrometer. The work consisted of drying samples of the original quartzite at temperatures of 200 and 800 °C with subsequent exposure to temperatures of 200, 400, 600, 870, 1000, 1200, 1470 and 1550 °C. As a result, the conditions for pretreatment of quartzite were established, during which during its further use, a cristobalite phase can be obtained, which makes it possible manufacture a high-temperature lining that ensures its high durability. The introduction of this technology will ensure the efficiency of the production of foundry products for enterprises operating induction crucible furnaces at industrial frequency

X-ray Diffraction Phase Analysis of Changes in the Lattice of Pervouralsk Quartzite upon Heating

At present, quartzite is widely used across many industries. The properties of quartzite significantly affect the technology used during the preparation of the raw materials as well as the technology used for manufacturing the final product, which may be intended for further operation at different temperatures. The purpose of the study was to create a scheme for the transformation of quartzite that would describe the changes in the parameters of its lattice parameter upon heating and would offer guidance regarding the drying technology and technology required to obtain tridymite. A Bruker D8 Advance diffractometer was used to study changes in the phase composition of quartzite at the temperatures of 200, 400, 600, 879, 1000, 1200, 1470, and 1550 °C. A detailed scheme of transformations of PKMVI-1 quartzite with a SiO2 content of at least 97.5% at normal pressure was proposed for crystalline modifications formed during its heating. As a result of this research, the changes in the parameters of the lattice parameter—such as the average interplanar distance davg, the volume of the unit cell Vavg, the density of the unit cell Davg, and the molecular weight Mavg—were established

Investigation of the Solid-Phase Joint of VT-14 Titanium Alloy with 12KH18N10T Stainless Steel Obtained by Diffusion Welding through Intermediate Layers

This paper describes the technological process of manufacturing bimetallic billets, which are capable of operating at high pressures, high temperatures, and in corrosive environments, from VT-14 titanium alloy and 12KH18N10T stainless steel. To obtain a joint with a strength of at least 350 MPa, the diffusion welding method was used, which makes it possible to obtain equal-strength joints using dissimilar materials. The connection of VT-14 titanium alloy with 12KH18N10T stainless steel after obtaining bimetallic billets with the desired properties was investigated. We studied the welded VT-14 and 12KH18N10T joint obtained by diffusion welding through intermediate spacers of niobium Nb (NbStrip-1) and copper Cu (M1). On the basis of our investigations, the optimum welding modes are as follows: welding temperature: 1137 K; welding pressure: 18 MPa; welding time: 1200 s. Mechanical tests, tightness tests, and metallographic, factographic, and micro-X-ray structural studies were carried out, the results of which indicate the effectiveness of the proposed approach