In this work, copolymers were obtained and a method for their synthesis was developed. Various fillers were selected to produce a polymer coating – microsilica and titanium dioxide. A new formulation of a protective polymer coating based on copolymers with corrosive properties has been developed. The possibility of using these polymer coatings in order to protect non-metallic surfaces of various products from the effects of aggressive media is given. The physicochemical properties of non-metallic samples (concretes) with a protective polymer coating, freshly prepared and aged for three months, namely water absorption and compressive strength, were determined. So, for samples with a polymer coating, after three months of exposure above the compressive strength is 93.3 kgf /cm2, for freshly prepared samples – 53.0 kgf /cm2. The same pattern is observed in aged and freshly prepared samples after water absorption (75.2 kgf/cm2 versus 24.0 kgf/cm2, respectively). The percentage of water absorption in aged samples is 0.0-11.63, except for the sample with a combined polymer coating of series 1 (water absorption is 23.28%). The percentage of water absorption of freshly prepared samples is 4.8-15.1, which is within good limits. At the same time, samples with a polymer coating and a microsilicon filler (series 3) and a combined polymer coating of series 3 have a minimum water absorption (4.8%).

https://doi.org/10.48081/POZA4679

2024

Issue 4

The article analyzes the effective input and output parameters of surface plasma hardening of railway wheels. Surface plasma quenching is considered as a complex technological process in which all internal and external parameters are interconnected and the choice of values of controlled parameters must be made taking into account these interrelated and interdependent relationships. The structural scheme of the surface plasma hardening technology for the production of solid-rolled railway wheels is considered, which is the basis for creating an integrated technological site in the current production process. Important parameters of the surface plasma hardening process are the maximum heating temperature of the surface layer and the cooling rate of the surface layer. The railway wheel includes the current and voltage, grade and consumption of plasma-forming gas, the angle of sharpening of the electrode, the diameter of the ceramic nozzle, the distance between the nozzle section and the surface of the processed material, the rotation speed of the wheelset, the grade of steel and its physic-mechanical properties. These parameters are variable, so they can be varied when developing plasma hardening technology. As output parameters of the surface plasma hardening process, in relation to railway wheels), the following are used: hardness of the hardened layer; crack resistance; depth of the hardened zone; width of the hardened zone; residual stresses in the hardened layer, the quality of the hardened surface and its roughness.

https://doi.org/10.48081/EBIP6992

2024

Issue 4

This article presents the research results of the changes dependence in the magnetic properties of 25CrMoV steel on the degree of products stress-strain state. This phenomenon of influence allows non-destructive detection of the steel products loading degree by determining magnetic characteristics such as coercive force and residual magnetic induction. These parameters are the main indicators of intensity and magnetization for the hysteresis loop of steels. Changes in magnetic characteristics during plastic deformation are due to the formation of the martensite phase. The effect of deformation causes the formation of the martensite phase due to the decomposition of austenite, which leads to significant changes in the physical properties of the material. Control of the stress-strain state of steel based on measuring the coercive force and residual magnetic induction in the controlled steel has a high potential for development and application. The data obtained prove that the coercive force and residual magnetic induction are a reliable informative parameter for magnetic non-destructive testing.

https://doi.org/10.48081/DLRF5238

2024

Issue 4

The study aimed to elucidate the mechanisms of micro- and macrostructural inhomogeneities in ingot cortical zones and their transformation into surface defects during heating, plastic deformation, and rolling. We developed and applied methods for analyzing macro- and microstructural as well as chemical inhomogeneities in ingots and finished rolled products. A comparative method for structural and concentration analysis of metal at all stages of metallurgical processing, from ingot to sheet metal, was proposed. This method utilizes metallographic techniques to study structure and qualitatively analyze nonmetallic inclusions. The results revealed that surface quality of sheet metal is significantly influenced by physical heterogeneity in the ingot crust zone, while internal defects in thin-sheet metal are largely determined by metal contamination with nonmetallic inclusions. A novel mechanism for defect transformation in the casting crust zone into surface and internal defects in sheet metal was proposed. This research deepens our understanding of defect formation and transformation processes in metal processing and contributes to the development of strategies to improve rolled product quality. Particular attention is paid to controlling ingot crust zone physical inhomogeneity and minimizing nonmetallic inclusion contamination to achieve highquality rolled steel.

https://doi.org/10.48081/WUSE7267

2024

Issue 4

This paper presents the results of casting process modeling with the assessment of the obtained macrostructure and geometry of the hollow and solid billets. The objective of the work is to develop recommendations for improving the existing technology of continuous casting of tubular billets and the design for its implementation, used at the pipe rolling plant of KSP Steel LLC. The main solution is to implement double-sided cooling of the hollow billet in the secondary cooling zone on the continuous casting machine. The optimal ratio of coolant consumption on the inner and outer surfaces of the billet is substantiated. The result of the proposed solutions is an improvement in the quality of the macrostructure and geometry of the billet. When analyzing the macrostructure of the billet, a decrease in defects by more than two times was revealed. The study of the cross section of the billet showed a decrease in the deviation of the minimum wall thickness from the maximum from 6.1 to 1.8 mm. The uniformity of mechanical properties according to hardness readings was increased from ±10.5 to ±3 HB.

https://doi.org/10.48081/ULEX7789

2024

Issue 4

This article presents an analysis of existing methods of image binarization. It systematizes data on the definition and description of various methods of image binarization developed by modern scientists. The aim of the research was to test modern binarization methods and determine optimal methods for binarization of images of microstructures of metals and alloys using samples of structural steel grades as an example. The following binarization methods are considered: binarization by the mean method, binarization using the C-shaped curve, Otsu's method (Ots or Otsu), multi-Otsu method, adaptive binarization, local binarization method, median method, Niblack algorithm, Sauvola method and Bernsen method. The advantages and disadvantages of these binarization methods are described. A test was carried out to apply a number of existing binarization methods for processing images of microstructures of steels and alloys using samples of structural steels for the purpose of their further application in information-digital metallographic analysis. The results of studies on the quality of the obtained images using various binarization methods are presented. The most suitable optimal methods of binarization of images of steel microstructures are determined for their further use in information and digital analysis of steels and alloys. The research is promising for further digitalization of metallographic analysis methods for metals and alloys.

https://doi.org/10.48081/QCEZ3788

2024

Issue 4

A section of the support is a program-controlled robot. Its load is an identification criterion for maneuvering the machine and ensuring the sta-bility of the face. The load as a distribution of pressures on the surface of its supports and arm joints determines the stress-strain state of the system. Its parameters are also determined by the type of roof shear. The peculiarities of the calculation of pressures on the robot's supports depending on the location of roughnesses from the processing of the face by a combine harvester and distributed according to the normal law have been studied. The values of pressures depend on the parameters of the supports and the distance to the bottom-hole. Increased interaction of their end parts with roof roughnesses causing their wear and blunting is taken into account. New elements to the system of load calculation with the use of dynamic programming technology of MS Adams package are proposed. It is shown: a three-zone scheme of support elements for volume interaction can degenerate into a two-zone scheme. Modeling of connections of supports and with rocks by Translational joint, Culindrical joint, Parallel joint allowed to take into account real interaction with rough roof in contrast to schemes with continuous contact. The developed method allows to take into account the moment when the robot support enters the zone of fresh outcrop, and the slab is loaded by the already separated and shifting roof block.

https://doi.org/10.48081/VFEY9313

2024

Issue 4

In the production activities of transport enterprises, an important place is occupied by issues of optimizing their economic and labor costs, which depend on the socio–economic situation, a set of objective reasons of a production nature, the availability of appropriate material and technical bases, their effective use and high–quality management of enterprises. This paper presents the features of the formation of the work program (order portfolios) of car service stations (СSS) in modern conditions and focuses on ensuring their stability. The main method in writing the work is the methods of mathematical modeling, mathematical and statistical analysis, and others. In the work, the production program of the СSS is presented as the sum of failures and malfunctions that arrive at the enterprise in a random order. The results of experimental studies are processed on the basis of the provisions of probability theory and mathematical statistics, mathematical models of the annual program and the probability of its distribution over a given time interval are obtained. Measures are recommended to optimize the production program by ensuring uniform loading of service station structures. There are also theoretical techniques based on certain results. This study provides experimental and theoretical research in the field of designing motor transport institutions and substantiates the method of calculating the annual program based on grouping the number of vehicles entering the enterprise.

https://doi.org/10.48081/VBOL2491

2024

Issue 4

In recent years, unmanned aerial vehicles (UAV) have gained widespread popularity due to their unique capabilities and diverse applications in various fields, including the economy, defense, and scientific research. However, their functionality is limited by a number of factors, such as flight autonomy and communication with the ground station. One of the key solutions for improving these aspects is the use of radiotransparent materials in UAV designs. Polymer composites with low dielectric characteristics and high radio transparency play a key role in modern telecommunications technologies, providing high signal transmission rates and a high degree of device integration. However, the creation of such dielectric polymer composites with the necessary characteristics is a difficult task that requires in-depth analysis and experiments. This paper presents comparative results of a study of dielectric losses and radio transparency of various composite materials, such as aramid-epoxy composite, fiberglass, carbon fiber and ultrahigh molecular weight high-density polyethylene. In this work, experiments have shown that the percentage of transmission for these materials varies: carbon fiber (CF) has only 2.45%, whereas aramid-epoxy composite (AEC) shows 79.43%, ultrahigh molecular weight polyethylene (UHMWPE) shows 80.16%, and fiberglass (FG) — 78.88%. The dielectric loss tangent angle of the UP is significantly higher than that of other composites, which indicates its low efficiency. At the same time, UHMWPE exhibits the lowest values of the tangent angle, and AEC and fiberglass have stable and low dielectric loss, which makes them promising for use in high-frequency devices and communication systems.

https://doi.org/10.48081/YAMS7377

2024

Issue 4

This article discusses a method for calculating the maximum allowable time of absence of radio communication in interval train control systems based on radio communication. A system of interval regulation of train traffic, operating on the basis of a radio communication channel of the latter type, is being intensively implemented on the railway network of the Republic of Kazakhstan. Mobile block sections are used in the system of interval control of train traffic based on the radio channel. Currently, this system operates on sections of the railway stationed on the basis of the Joint–Stock Company "National Company"Kazakhstan Temir Zholy" Uzen – Bolashak (143 km), Zhetygen - Altynkol (280 km), Arkalyk-Shubarkol (214 km), Shalkar –Beineu (471 km) and Zhezkazgan-Saksaulskaya (517 km). However, at present, on railway sections where a radio-based interval train control system has been put into operation, there is a large loss of radio communication between the radio communication center and the on-board train system. The longer the loss of radio communication persists, the greater the negative impact trains have on the schedule. In this regard, one of the urgent issues is to establish the maximum time limit for restoring radio communications by calculating the maximum allowable time of absence of a radio communication channel in such systems. Applying in practice the calculation methods described in the article, taking into account the time spent on restoring radio communications, it is possible to consider the possibility of using a backup communication channel for this time interval for the smooth operation of the system in question.

https://doi.org/10.48081/XMCL2311

2024

Issue 4