One of the important problems of practical application of high-strength plasma surfacing of high-speed steels in a nitrogen environment is the analysis of the damping properties and adhesion of the surfacing and the substrate, since these properties largely determine the premature nucleation of brittle microcracks in the contact zone. Such results can be obtained only using highly informative methods of modern materials science, such as scanning and transmission electron microscopy. In the article, surfacing of tungsten-molybdenum steel P2M9 has recently found wide application instead of well-known tungsten (type P18, P9) and tungsten-molybdenum steels with increased tungsten content (type P6M5, P6F2K8M6, etc.). This is due to the need to replace expensive and scarce tungsten with molybdenum, which, being in the same group of the Periodic Table of Elements with W, has a similar effect on the structure and properties of high-speed steels. The structural-phase states, morphology and elemental composition of the transition zone of the contact of the system "deposited high-speed steel R2M9-substrate (steel 30KhGSA)" in the initial state and after triple high-temperature tempering were studied. In the initial state, the transition zone has a martensitic structure with layers of residual austenite along the boundaries of martensite plates. Particles of the second phase of the nanosized (2 ‒ 60 nm) range were revealed – vanadium, molybdenum, tungsten and iron carbides localized at dislocations, at the boundaries and in the volume of martensite plates. Triple high-temperature tempering does not change the morphology of the carbide phase particles of the transition zone. Possible physical causes of the observed patterns are discussed.

Polymer self-adhesive materials are widely used in various industries (construction, medicine, packaging, automotive, advertising, electronics and consumer goods). Their popularity is due to their operational characteristics: resistance to external influences and ease of use. The results of studies of the surface properties of polypropylene (PP) films modified using low-temperature plasma of atmospheric pressure glow discharge are presented. The treatment time was 3, 5, 10, and 15 seconds, and the plasma was initiated in technical argon, air, and mixtures thereof in the proportions of 70:30, 50:50, and 30:70. The study shows that the plasma modification significantly improves the adhesive properties of polypropylene, doubling them compared to the original sample. The maximum adhesion performance (135.5 MJ/m²) of PP was achieved with modification in argon for 15 seconds, which doubled the adhesion properties compared to the initial sample. An increase in the processing time of more than 15 seconds does not affect the adhesive properties and the wetting edge angle. A mixture of argon and air was used to reduce argon consumption. The optimal 50:50 ratio ensured an edge wetting angle of 42 ± 1° and an adhesion of 127.9 MJ/m² (close to the values of pure argon). An increase in the surface roughness of modified PP films was noted from 52.6 to 199.4 nm in argon, to 133.1 nm in an argon‒air mixture (50:50). Increasing the roughness facilitates the application of glue and strengthens the adhesive bond. The study investigated the kinetics of changes in the electret properties of PP films and their effect on adhesive properties. The results obtained during the study are recommended for the development of basic materials for self-adhesive products with improved performance properties.

A study of the microstructure and properties of a titanium alloy formed during electron beam printing with VT6cw wire after treatment with a pulsed ion beam has been carried out. The samples were obtained at a laboratory facility for electron beam additive manufacturing developed at IFPM SB RAS. The process of forming the samples was carried out by fusing titanium welding wire of the VT6sv brand with a diameter of 1.6 mm under vacuum conditions at a pressure of 10^‒3 ‒ 10^‒2 Pa. The energy effect using pulsed ion treatment was carried out on a TEMP-4M accelerator at an accelerating voltage of 200 kV, a pulse duration at half the maximum of 100 ns and an energy density of 2 J/cm². Transmission electron microscopy, atomic force microscopy, and microhardness measurements have shown that exposure to a pulsed ion beam leads to significant changes in the microstructure of the surface: the transformation of the β-phase into the α-phase is observed, as well as the formation of nanoparticles of the Al₃v intermetallic compound. The thickness of the modified layer is about 5.5 microns. A slight increase in microhardness was revealed (from 254.39 to 261.37 HV), while a more uniform distribution of hardness values was achieved. Ion beam treatment can help improve the biocompatibility of titanium implants by eliminating sharp edges that occur during machining and reducing roughness. In comparison with traditional methods of thermal treatment, ion treatment demonstrates a high degree of controllability and adaptability, which makes it promising for use in biomedical systems. The results obtained open up new possibilities for the functionalization of the surface of titanium alloys and have high application potential.

Modification of the surface layers of products made of metallic materials is accompanied by a change in performance characteristics: hardness, wear resistance, and heat resistance increase. Currently, laser processing, electron beam and plasma alloying, including electro-explosive alloying, are used to modify the surface. The application of modern methods of surface hardening using concentrated energy flows (such as electro-explosive alloying and electron beam treatment) is especially relevant for local effects on titanium and titanium alloy products. The aim of the work was to identify the formation of structural and phase states during electro-explosive alloying and electron beam surface treatment of technically pure titanium grade VT1-0 from the point of view of increasing functional properties for practical use. The developed method for hardening the titanium surface includes electro-explosive carburization and subsequent electron beam treatment of the alloying zone. The features of each method determine the choice of processing modes. The thermal processes during these treatments have been studied, taking into account the specifics of each method, which makes it possible to reasonably choose the treatment modes. The effect of electron beam processing modes on the microhardness of the surface layers, the formation of maxima in the depth of the alloying zone, and a multiple increase in the microhardness of the surface layers has been established. The features of the structural and phase states and the mechanisms of hardening of the surface layers of technically pure titanium during electroexplosion carburization and subsequent electron beam treatment are revealed. A gradient multiphase structure is formed in the treatment area, the thickness of the layers of which correlates with the depth distribution of microhardness. Based on the experimental data obtained, it is concluded that the combined surface treatment of technically pure titanium grade VT1-0, combining electro-explosive carburization and subsequent electron beam treatment of the alloying zone, provides an increase in microhardness and depth of the hardening zone.

Using the direct laser cultivation method at the ILIST-L installation, samples of stainless steel grade 12X18H10T were obtained at a laser radiation power of 1100 ‒ 1500 W with a wall thickness of 10 mm for the case of horizontal and vertical directions of growing samples relative to the larger side. The hardness and microhardness of the samples were studied, and their dependences on the growing regime were revealed. It has been established that the most rational mode, in which uniformity and a high level of properties are achieved, is the mode with a power of 1400 watts. The vertical growing direction, which causes more intense cooling of the samples, allows for an average of 5 to 15 % higher microhardness than the horizontal growing direction. An increase in power from 1100 to 1400 W reduces this difference to zero, but a further increase in power to 1500 W increases the differences by up to 15 % due to a decrease in the microhardness of horizontally grown samples. Regardless of the direction of cultivation, in the entire range of power values (from 1100 to 1500 W), the hardness of 12X18H10T grade steel in the near‒surface areas has values reduced by 15 ‒ 17 % compared to the central region of the samples. The study of the effect of the parameters of the layer deposition mode on the hardness and microhardness of manufactured products made of 12X18H10T grade steel by direct laser cultivation provides the basis for choosing the laser power and understanding its effect on the mechanical properties of stainless steel in different growing directions.

One of the ways to increase the efficiency of steelmaking is to increase the service life of refractory lining. The durability of the lining is determined by the composition and properties of the refractories, the conditions of its execution and subsequent operation. The influence of steel smelting parameters on the resistance of the refractory lining of flexible modular furnaces (GMP) operated in the conditions of the Ural Steel electric steelmaking plant (ESPC) since 2019 has been studied. A special feature of the GMP is the ability to operate both in the mode of an arc steelmaking furnace (chipboard) and in a mode without the use of electric energy, that is, using converter melting technology with an increased proportion of cast iron. The durability of the GMP lining during the studied campaigns varied widely from 270 to 450 heats, with an average of 328 heats. The results of a study of the influence of the main technological parameters of steel smelting in a flexible modular furnace on the stability of the lining of walls and hearths are presented. It is shown that the main technological factors determining the durability of the lining and the duration of the GMP campaign are the duration of downtime (inter-melting periods), the oxidation of slag and the content of MgO oxide in it. Quantitative dependences of the influence of the studied technological parameters of melting on the resistance of the refractory lining are obtained. Technological recommendations have been developed to extend the service life of the refractory lining: reducing the duration of inter-melting periods, reducing overoxidation of metal and slag as a result of stopping purging at a given carbon content (in accordance with the grade of steel being smelted), increasing the content of MgO oxide in the slag to 8 ‒ 10 %. The implementation of technological recommendations will increase the resistance of refractory lining by at least 25 % with a corresponding reduction in costs for refractories and repairs.

The structural and phase state, durometry, and metallography of samples cut from flat rolled steel of grade 20 subjected to plastic tensile deformation are considered. Some of the samples were subjected to surface hardening by chemical heat treatment (CTO) before stretching, the second part was subjected to heat treatment (TO). Both treatment methods were carried out at the same temperature regime (850 C with 180 min exposure). At the same time, the task of changing the mechanical properties during heat treatment was not set for the material in question. The microstructure was studied in the directions along and along the rivers of the rolling direction. The effect of thermal and chemical-thermal treatments on the static strength and impact strength of the samples after the corresponding processes was investigated. During plastic stretching deformation, the thickness of the diffusion layer does not change, except for the area located in the fracture zone: the thickness of the diffusion layer increases slightly, but the layer itself is already a conglomerate of fragmented fragments of boride needles, nevertheless, quite firmly connected to the matrix material. It is shown that plastic deformation leads to an increase in the anisotropy of the grain in the direction of the forces, and during plastic deformation, it is crushed by crushing excessively elongated inclusions into smaller fragments in the direction perpendicular to the action of the deforming force. The measurements of grain anisotropy show that in both cases it is close to unity (0.99 for CTO and 1.02 for TO), which suggests that in both cases equi-axial grains are observed, which are close to globular in shape. A comparison of the microstructure of the core of both samples (borated and non-borated), which underwent identical thermal treatment, showed that the microstructure of the core of the samples under consideration is absolutely identical: both the phase composition and the structural state coincide.

The working space of the converter is considered as a set of separate reaction zones, which contributes to the study of the mechanism of physico-chemical phenomena in each zone and in the oxygen jets – metal – slag – exhaust gas system as a whole. The fulfillment of similarity conditions allows high-temperature modeling to be qualitatively implemented in a certain range, and a partial violation of one or another of the considered similarity conditions will lead to the implementation of only approximate modeling. The analysis and substantiation of the main provisions of the methodology of high-temperature modeling of the converter process with combined purging of the converter bath has been performed. The basic conditions of aerohydrodynamic and dynamic similarity are formed when using multi-pulse gas flows for purging a melt, which, together with the conditions of geometric and physical similarity, make it possible to transfer the results obtained from the model to the sample with greater reliability. A technological map is developed preliminarily for each experiment, providing the specified parameters of blast and slag melting modes using fractional lime and fluorspar additives. The considered conditions and the basic dimensionless similarity criteria make it possible to transfer the results obtained to industrial designs. A set of laboratory facilities and techniques has been developed and improved that make it possible to visualize the interaction of gas jets with a slag-metal emulsion in a converter using photo and video recordings, to obtain information about the parameters of the reaction zones formed and the gases escaping to the surface of a metal bath.