Siberian State Industrial University

The high growth rates of metallurgical production lead to an increase in the use of mineral raw materials necessary for conducting metallurgical processes. In almost all metallurgical processing, crushed brittle material is required as a feedstock, obtained using crushing machines, which are also used to process the resulting products of metallurgical processing: slags, ferroalloys and others. The design of an energy-efficient single-roll crusher with a roll stop is considered, in which the destruction of the initial piece occurs due to the creation of a complex stress state in the mate-rial. The creation of such a stressed state in the material being destroyed helps to reduce the energy consumption for crushing compared to crushers working on compression by 60‒70 %. A distinctive feature of such a crusher is the forced supply of the destroyed material to the crushing zone. In case of forced feeding of the loaded material, the per-formance evaluation is determined by the volume of the loaded material per unit of time. This is due to the fact that the loading of the initial pieces is carried out discretely. The developed methodology for calculating productivity is based on the condition that a loaded volume of material consisting of pieces of a given initial fraction is processed in one revolution of the roll. The size of the initial piece fed into the crushing zone is determined from the considerations that the size of the initial piece should be larger than the gap that sets the size of the finished fraction, while the working surface of the stop contacts the crushed piece at a point located on a tangent drawn from the center of the roll through the extreme point of the piece. In the limiting state, the upper edge of the working surface of the stop contacts this point, in this case, the size of the initial piece reaches its maximum value

The article is devoted to studying the influence of industry specialisation of the Kemerovo region – Kuzbass on the economic growth of the entity. The purpose of the study is to identify the most significant trends and problems of the industry specialisation that affect the development of the region. Using methods of scientific knowledge – description, synthesis and generalisation of the data obtained; literature review, graphical method – the following has been conducted: analysis of the dynamics of structural changes in the gross regional product (hereinafter referred to as GRP) of the Kemerovo region – Kuzbass; assessment of trends in the movement of main industry indicators and indicators of regional industry. The information base of the study consists of foreign and domestic publications devoted to the analysis of the GRP sectoral structure; statistical data from the Federal State Statistics Service and its territorial authority for the Kemerovo Region – Kuzbass. Based on the analysis of the structural changes dynamics, an increase in the contribution of the raw materials sector to the country’s gross domestic product and an increase in the share of mineral extraction in the industry structure of the GRP of the Kemerovo region – Kuzbass have been revealed. The trend of decrease in the industrial production index is analysed, it is shown that it has a trend similar to the dynamics of the decline in mining production, and the reasons for the decline are described. The strengthening trend of economic growth in the Kemerovo region – Kuzbass based on the raw model has been determined. East Asian models of economic growth are considered. The expediency of using international experience in the design of high-tech industries on the basis of private investment in the research and development sector, and its adaptation to the realities of the development of Russian regions is indicated. A conclusion is drawn about the need to support the technological sovereignty of the country and the transition of the development of the Kemerovo region – Kuzbass to a non-primary model.

A coating of the TiB 2 -Ag system was formed through the use of sequential operations of electroexplosive spraying and electron beam processing. The values of electrical conductivity (62.0 MS/m), Vickers microhardness (0.251-0.265 GPa at the point of measurement on a silver matrix and 25-32 GPa at the point of measurement at inclusions of boride phases), nanohardness (4.48 ± 0.76 GPa) were determined), Young’s modulus (116±29 GPa), wear parameter under dry friction-sliding conditions (1.2 mm ³ /N • m) and friction coefficient (0.5). Switching wear resistance during accelerated tests was 7000 on and off cycles with an electrical resistance of 10.01 - 11.76 LiOhm. The thickness of the coatings is 100 microns. The coatings are formed by a silver matrix with inclusions of titanium borides located in it with three types of sizes: nanocrystalline, submicrocrystalline and microcrystalline. Quantitatively, in the structural composition among titanium borides, titanium diboride and silver (56 wt. %) are formed predominantly (41 wt. %), while other titanium borides account for 3 wt. %. Structural transformations are described using complementary methods of X-ray phase analysis, scanning and transmission electron microscopy.

In the metallurgical industry, approximately 40 % of the energy spent on raw material preparation for further processing accounts for the processes of brittle materials destruction in crushing machines. From the analysis of operation of crushing machines, differing in the method of creating stresses in a destructible piece of brittle material, it follows that the best, from the point of view of energy efficiency, is the one in which tangential stresses (shear deformation) are generated in the processed material. The authors describe the design of a crushing machine which ensures that during the crushing process only tangential stresses arise in the piece, causing shear deformations.

Using transmission electron microscopy methods, the structural-phase states and defective substructure were studied at distances of 0; 2 and 10 mm from the surface along the central axis and rounding radius of rails head fillet. Differentially hardened long rails of the DT400IK category made of hypereutectoid steel have been studied after operation on the Trans-Baikal Railway (passed tonnage equal to 234.7 million tons gross). It has been established that steel strength characteristics are determined by certain physical mechanisms. A qualitative assessment of the contributions from crystal lattice friction, solidsolution strengthening, strengthening of the pearlite component, incoherent cementite particles, grain boundaries and subboundaries, dislocation substructure and internal stress fields was carried out, and their hierarchy was established. A quantitative assessment of the additive yield strength of steel in different directions was carried out depending on the distance from the rolling surface. It is shown that the main mechanisms of strengthening are strengthening by incoherent particles, long-range stress fields and substructural strengthening. The additive yield strength on the fillet surface is significantly greater than on the rolling surface of the head along the central axis.

Today, researchers and industry are faced with the task of improving the physical and mechanical properties of various metal products. To strengthen the structures, there are various technologies for processing the material surface by high-temperature exposure. At the same time, the use of laser technologies is of great interest. High-speed local laser heating of the material surface followed by rapid cooling with heat removal into the volume depth, as well as the absence of mechanical action, allows us to obtain unique nonequilibrium structures with a wide range of properties. Obviously, the development of these technologies requires deep fundamental research. In this work, the molecular dynamics method revealed the features of structural changes in the surface layers of an iron crystal under high-temperature exposure. The choice of such a method is due to the fact that the phenomena under consideration are difficult to study through real experiments and direct observations. Conditions of the computer experiment were set in such a way that after the melting point is reached, a phase transition occurs in the simulated system, during which particles are separated from the surface of the liquid phase. As a result of the study, the threshold temperature of particle ejection was estimated and the mechanisms of particle cluster formation were investigated. When heated, the number of clusters increases, and when cooled, it decreases, but at the same time their sizes increase, which indicates the implementation of the condensation mechanism of ablation products. Additionally, the influence of external pressure on the simulated particle system was studied. It is shown that as the pressure increases, the number of clusters decreases.

Hydraulic dumps for storing waste from primary and secondary iron ore processing (tailings dumps) were selected as objects for research. In the course of the study, data on the mineralogical composition of soil-forming rock samples of technogenic landscapes were obtained. This indicator is one of the main factors of soil formation when considering lithology at a lower hierarchical level. The mineralogical composition influences the content and ratio of nutrients and toxicants in soils, ion exchange processes, soil resistance to degradation and overall soil fertility. The mineralo­gical composition is the matrix of soil formation and regulates the transformation, migration and accumulation of matter, energy and information of the external environment and anthropogenic impact in the soil. The hydraulic filling method of waste storage has an impact on the spatial distribution of material in tailings dumps. First of all, a contrasting addition in terms of granulometric composition is distinguished due to the deposition of particles in aqueous conditions under the influence of a gravitational field. The deposition rate depends on the mass, size, shape and density of the particle substance, viscosity and density of the medium, as well as on acceleration, gravity and centrifugal forces acting on the particles. Despite a significant amount of research on the effect of mineralogical composition on soil development, this problem was not sufficiently studied. This determines the absence of generally accepted indicators of the development rate of soils formed on a man-made mineral substrate and the accumulation degree of biophilic elements in such soils.

In this work, the authors used the methods of modern physical materials science to investigate the structure, defective substructure, phase composition, tribological and mechanical properties of the surfacing subjected to high-temperature tempering at 580 °C and subsequent electron beam processing. The deposited layers up to 10 mm thick are formed by plasma surfacing with PP-18YU powder wire in a nitrogen medium. According to the phase composition, the deposited layers consist of α-Fe and carbides of Me 6 C composition. After tempering, the polycrystalline structure of the deposited layer contains grains of 7.0 – 22.5 μm in size with layers of the second phase along the boundaries and at the joints of grains with composition V 4 C 3 , Cr 7 C 3 , Fe 3 C, Cr 23 C 6 , WC 1 – x . Electron beam processing forms a thin surface layer (30 – 50 μm) with grains of cellular (columnar) structure of high-speed crystallization of submicron (100 – 250 nm) size. Particles of the second phase of the nanoscale range of globular and faceted shapes were detected in the volume of grains and along the boundaries.

In this study, we aim to identify shortcomings in the operation of multisatellite planetary gearboxes and to justify improved designs of planetary self-aligning mechanisms, which allow torque to be transmitted through all installed satellites. To that end, we studied a domestic planetary three-satellite MPZ gearbox installed on a magnetic separator, designed for wet separation of strongly magnetic ores and materials into magnetic and non-magnetic products, and a planetary gearbox of a special structure. 3D models of the classical three-satellite and single-sliding self-aligning gearboxes were constructed in the 3D module of the T-Flex CAD software. The performance of the mechanisms was evaluated by structural analysis and Chebyshev’s mobility formula. The constructed 3D models were used to study the engagement process of the classical three-satellite and single-sliding self-aligning gearbox. The latter is distinguished by the presence of two levers, which are introduced additionally to three satellites. During the research, the lateral clearance between the pairs of satellite teeth and center wheels was accepted according to GOST 1643–81. The conducted analysis of contacts at rotation of the central driving wheel by 30°, 110°, 200°, and 310° established further designing of the applied planetary gears to be inexpedient due to impossibility of realization of power transfer simultaneously through all satellites. The main disadvantage of the operation of multisatellite gearboxes was found to be the requirement for the side clearance selection, which should ensure the operability of the transmission at the moment of motion transfer. When designing multi-satellite single-slide selfaligning planetary mechanisms, additional levers should be introduced into the structure, the number of which should be equal to the number of satellites. Hence, the use of self-aligning planetary gears makes it possible to reduce the dimensions due to the uniform distribution of the transmitted torque, since the calculated value of the torque can be reduced by the number of satellites. This allows the gears to be adapted to the working loading conditions, which significantly improves the performance of the entire machine or unit.

Glaciers and glacierets of the Kuznetsky Alatau mountains are distributed at altitudes of 1200–1500 m above sea level, which is not typical for continental areas. The main factor contributing to the persistence of glaciation here is abundant winter precipitation. According to ground surface temperature measurements, the negative annual values are typical for upper glacier’s boundaries only. Since intensive study during the compilation of the USSR Glacier Inventory (1965–1980), the glaciation of the region has undergone notable changes. To assess the current state of glaciation, Sentinel-2 satellite images were used; contours of the glaciers were traced on the basis of images from 2021–2023. In total, 78 glaciers and 57 glacierets were identified. UAV imagery and field inspection were used for validation. The total glaciated area has been reduced from 8.5 to 3.1 km ² , which is 50–75% for selected river basins, with slope morphological types decreasing the most. However, the elevation changes are negligible.

The molecular dynamics method was used to study the structure formation during austenite nanoparticles crystallization in the presence of carbon impurities. The paper describes the dependence of the melt cooling rate, particle size, concentration of carbon atoms in the particle on the resulting structure features during crystallization and temperature of the crystallization onset. Formation of the nanocrystalline structure of nanoparticles can be controlled by varying the cooling rate and introducing a carbon impurity: at a cooling rate above 1013 K/s in the model used, crystallization did not have time to occur; at a rate below 5·1012 K/s, the austenite particle crystallized to form a nanocrystalline structure. At the same time, with a decrease in the cooling rate, a decrease in the density of defects in the final structure was observed. At a rate of 5·1011 K/s or less, crystallization of carbon-free particles took place with the formation of low-energy grain boundaries (with a high density of conjugate nodes: special boundaries, twins). The crystallization temperature during cooling at a rate below 1012 K/s is inversely proportional to the particle diameter: as the particle size decreases, the proportion of free surface increases, which leads to a decrease in the probability of crystalline nuclei formation. In addition, the crystallization temperature increases with a decrease in the cooling rate. The introduction of a carbon impurity led to a decrease in the crystallization temperature of nanoparticles: in the presence of 10 at. %. As a percentage of carbon, it decreased by about 200 K for particles of different sizes. Carbon atoms often formed clusters consisting of several carbon atoms. Such clusters distorted the resulting crystal lattice of metal around them, preventing crystallization. In the presence of a carbon impurity, the final structure of the crystallized particles contained a higher density of grain boundaries and other defects. Carbon atoms, especially clusters of them, were fixed mainly at grain boundaries and triple joints.