An analysis of the state of foundry production in the world is presented, as well as an analysis of the state of foundry production in the Republic of Belarus. The dynamics of changes in production capacities, the degree of loading and the volume of production of castings for various types of alloys is shown. It is established that the structure of cast products produced both in the world and in the Republic of Belarus is in constant dynamics and there is a constant change in the ratio of production volumes from various alloys. The development of the foundry production of the Republic of Belarus as a whole is similar to the world foundry production, however, there is a certain time lag and certain differences in the ratio for different types of casting.

It has been shown that hydrogen and oxygen atoms cannot be present in the open pores of crystal lattices of base metals of casting alloys. The solubility of gases in liquid casting alloys is a nanostructured process. Hydrogen and oxygen atoms in melts are adsorbed by basic metal elemental nanocrystals. Nitrogen dissolves in liquid iron, nickel and chromium not in atomic form, but in the composition of elementary nanocrystals and nitride molecules. After deoxidation of molten casting alloys, the main gas dissolved in them is hydrogen.

The article is devoted to the selection of optimal parameters of a chemically hardening mixture based on quartz sand with a liquid‑glass binder cured with liquid esters for the production of castings of heavy machinery, machine tools and shut‑off valves. The analysis of the quality of molding sands of three brands, of different origin, was carried out. The strength characteristics of mixtures of various compositions are studied. Based on the data obtained, conclusions are drawn about the optimal characteristics of sand and the amount of binder additive. The compositions of easily knocked‑out environmentally friendly liquid‑glass mixtures cured with esters for the manufacture of molds and rods in machine‑tool armature construction are recommended.

Variants of preparation of production of castings from aluminum alloys in conditions of single and small‑scale production are considered. It is established that in order to reduce the time and cost of obtaining castings, it is most expedient to carry out end‑to‑end design and manufacture of technological equipment using additive technologies and casting in sand‑resin molds obtained using the “no‑bake” technology.

It has been experimentally shown that directional solidification of water and bismuth in glass and quartz cylindrical forms does not result in expansion of the castings perpendicular to the solidification direction. Therefore, such forms are not destroyed. This is due to the unobstructed release of gases during directional solidification of water and bismuth. Gases have a great influence on the expansion processes of castings when they solidify.

The study investigated the major Causes of inconsistency in the cast results of the aluminium cast products from the metal moulds supplied by the then Hungarian Technical Partners to Scientific Equipment Development Institute, Minna. The metal moulds for different scientific products for Schools Scientific Laboratories were to achieve mass production of these products. The aluminium alloy A6063 ingot used were likewise imported. However, another consignment of the ingot used is produced in Nigeria by Nigerian Aluminium Extrusion Company, Lagos. Result of the products defects including shrinkage, blow holes, etc. remained the same, hence the need for this investigation work to ascertain the causes traceable to either moulds or the class or group of alloys.
The outcome as shown could be that pouring speed or melting temperature etcetera are responsible for the inconsistency in obtaining acceptable cast products at different operations and with these moulds. A particular product mould gives inconsistent cast products and varying defects. This is applicable to all the available moulds supplied to the Institute at the same time.

It is shown that hydrogen is a demodifying element of the structure of cast magnesium alloys during their crystallization. Hydrogen atoms, adsorbing on elementary nanocrystals in melts, prevent the combination of nanocrystals into the nucleus of crystallization of α‑phase microcrystals. As a result, molds with an unmodified structure are formed. Modifiers reduce the concentration of adsorbed hydrogen in the melts of magnesium alloys. This results in the milling of α‑phase microcrystals in castings as they solidify.

The main goal of any modern production of long products is to ensure the required quality of finished products. One of the important quality indicators, along with mechanical and technological properties, is the quality of the rolled metal surface. The article presents the results of experimental studies of the composition of high‑temperature diffusion oxides formed on the surface of artificially deposited defects under various conditions of temperature exposure using the microrentgenospectral method on a scanning electron microscope with an energy dispersive microanalyzer. The characteristic features in terms of the percentage and presence of certain chemical elements in the scale of various steel grades have been established.

Defects on the outer surface of seamless hot‑rolled steel pipes are formed both as a result of the defects’ transformation in the surface and macrostructure of the initial workpiece, and due to non‑compliance with the rolling technology. Timely detection of defects and elimination of the causes of their formation, allows you to get high‑quality products with high operational reliability. Detection of violations of technology, control of the technological process, carrying out metallographic studies allow classifying defects and establishing the nature and causes of their formation.

The article presents the results of a metallographic study of a defect on the outer surface of a hot‑rolled seamless pipe. The genetic and morphological signs of the defect were determined. Descriptions of the appearance of the defect, the microstructure in the defect zone are given. A comparative analysis of the defect detected during magnetic powder control with defects on experimental pipe blanks with artificial defects was carried out. Based on the data obtained, the causes of the defect formation are determined, its classification is given.

Dispersed iron‑containing waste makes up the majority of solid technological waste of machine‑building and metallurgical enterprises. The problem of their disposal remains open, which leads to significant economic losses and creates a serious environmental threat. About 15–20 % of these wastes are assirative dusts of melting units. The content of compounds of various metals, and primarily iron, in some of them (for example, in the aspiration dust of arc steelmaking furnaces) reaches 60–70 % or more. However, today, despite all efforts, no more than 5–7 % of the captured aspiration dust of melting furnaces is used. One of the most significant problems of its disposal is the high dispersion (the size of the dust particles of arc furnaces, as a rule, does not exceed 50 microns) and the extreme heterogeneity and instability of the granulometric and chemical composition of the dust. Therefore, in most cases, attempts to use these dusts as a technological product: additives in molding and exothermic mixtures or non‑stick paints, coloring pigment in the production of building materials, modifying additives in the melting of foundry alloys, additives in the production of cement clinker, etc., ended at the level of experimental or pilot batches and were not essential for solving problems in general. The most promising direction of utilization of aspiration dusts is the recycling of metals contained in them. This article presents the results of studies of the composition and characteristics of aspiration dust of arc steelmaking furnaces of foundries of machine‑building plants, as well as the conditions of solid‑phase reduction and extraction of iron contained in it.

JSC “Uzmetkombinat” is one of the largest metallurgical enterprises of the Republic of Uzbekistan. Along with the main products – long products from ferrous and non‑ferrous metals of various assortments, steel grinding balls, ferroalloys, the plant also produces heat‑insulating materials, consumer goods and other products. JSC “Uzmetkombinat” is a developing enterprise – year after year it increases its production capacity, opens new production facilities and increases the range of products. This article provides information about the plant, the range of products, production indicators for previous years and targets until 2026, as well as ways to achieve them.

The relationship between the localization of plastic deformation in the initial stage of deformation and in the final stage during the development of the neck is established. The role of the intensity of deformation hardening in the area of local deformation on the formation of the magnitude of relative constriction is determined.

The article presents the research’s results in the field of multifunctional ceramic materials synthesis for metallurgical, machine‑tool and other branches related to the metal treatment, their alloys and products from them; current trends and tendencies associated with the production of goods from such materials. The information on expanding the local raw material sources for the production of ceramics with the involvement of local enterprises is provided. In addition, the prospects for the industrial potential development to produce such goods are observed.

The paper presents the results of a study of the regularities of the formation of granulometric composition, structure and properties of modifying ligatures with a high content of alloying component for the production of chrome bronzes. The kinetics of changes in the physico‑mechanical properties of granular compositions depending on the temperature in the grinding chamber and the ratio of the volume of working bodies to the volume of the charge has been studied. The results of the topography of granules and their structure are presented, showing that the granules obtained according to the optimal mode of mechanical fusion are dense bodies with microinclusions of chromium, the maximum size of which does not exceed 15–20 microns.

Based on the results of thermodynamic modeling, thermodynamically justified refractory compounds synthesized in the process of obtaining a ligature have been established, which should effectively perform the role of modifiers of the first kind, ensuring the production of bronzes with a sub‑/microcrystalline type of base structure.

The processes of compacting mechanically fused compositions were optimized and the influence of the main technological factors – the heating temperature of cold‑pressed briquettes and the extraction coefficient during hot pressing on the physical and mechanical properties of compact materials was investigated. The results of studying the structure and properties of the most promising Cu – 20 %Cr composition are presented, which make it possible to identify its microcrystalline type, which persists after prolonged high‑temperature exposure during the processing of the granular composition into a semi‑finished product, and to conclude about the dispersed nature of its hardening, which additionally confi ms the data of thermodynamic modeling on the possibility of mechanical synthesis of nanocrystals of refractory compounds to perform the role of modifiers.

According to the results of the research, a comparative analysis of the properties of the developed ligature and beryllium bronze was performed, establishing the possibility of its use as an independent material for electrical purposes.

The analysis of the ring rolling machine capabilities in providing increased accuracy of ring blanks is performed. The necessity of operator’s participation in controlling the ring rolling machine to achieve the required accuracy even with full automation of the ring blanks manufacturing process is noted. The necessity of controlling the process of cooling of circular blanks after the circular rolling machine to ensure increased accuracy of the circular blanks has been noted. To eliminate the ovality of low rigidity ring blanks after the circular rolling mill it is proposed to use the technology of their controlled cooling and stabilization. The sequence of thermal strain control of the ring blanks during cooling to preserve the achieved accuracy of the “hot” ring after the ring rolling on the “cold” ring after cooling has been developed. The proposed recommendations are intended for the development of technological support for automated ring rolling complex at OJSC “BELAZ”.

The article considers etch pits that appear in metals and alloys during metallographic etching as an artifact. The optical contrasting tools capabilities, such as dark field, polarized light, and differential interference contrast in detecting etch pits, are demonstrated.

The study is dedicated to the electric pulse pressing use for the composite materials production from diffusion‑alloyed iron powders. It is shown that the addition of a low–melting metal component, tin, has a positive effect on the compaction of the composite iron powder during electric pulse pressing. The density of samples from Dystaloy AB iron powder with the addition of 10 % tin reaches 7.3–7.5 g/cm3. It is impossible to obtain such a density in the conventional cold pressing process at a pressure of 100– 120 MPa. It is established that due to the short duration of thermal exposure during electric pulse pressing, diffusion processes do not have time to pass and the distribution of alloying elements in the iron base is uneven. A short thermal exposure causes oxidation of the surface of the powder particles, which also negatively affects the diffusion processes. Therefore, when obtaining alloyed powder materials by electric pulse pressing, the process must be carried out in a protective atmosphere. The revealed presence of a nanoscale substructure formed due to the effects of intense plastic deformation and temperature indicates the hardening of the powder composite material during electric pulse pressing. These features can be useful in the development of technologies alternative to the warm pressing of plasticized powders.

The paper considers the technological features of thermodiffusion galvanizing of fasteners in a powder mixture containing the main waste of hot galvanizing it is gartzink. The advantages of preliminary fluxing over thermal diffusion zinc plating are noted. The microstructure of the obtained diffusion layers on steel 40Х was studied, the features of the saturation kinetics and the quality of the resulting layers were noted.

In this work, the task was to investigate the processes of microstructure change occurring in relatively large bulk bars under the action of large plastic deformations. Such large levels of deformation are usually achievable in high pressure twisting of small flat disks, but are difficult to achieve in large bulk bars. The method of radial shear rolling makes it possible to achieve comparable ultrahigh degrees of deformation (~45 mm/mm) in combination with the vortex flow of the metal. Sequential rolling of the E110 zirconium alloy was carried out under extreme conditions on 2 radial shear rolling mills with a total diameter reduction ε = 185 % and a maximum accumulated strain = 46 mm/mm. To assess the level of deformation and its distribution over the section, FEM modeling was carried out in Deform‑3D. The resulting structure was studied by electron microscopy (TEM/SEM). A detailed cross‑sectional study of the EBSD structure was performed with a resolution of 1 mm. A gradient structure with a predominance of an equiaxed ultrafine‑grained structure was found, which was not very pronounced compared to the use of smaller deformations.

The results of the dust content study at workplaces of foundry parts with different production patterns are considered. It is noted that the dust content in the foundry sections working area air exceeds the maximum permissible concentrations at all workplaces, while the greatest exceedances are noted in mass production workshops. The greatest impact of dust is exposed to the cutters, cleaners and casting technicians.

The working conditions at the workplaces of foundry workers when performing finishing operations, production factors determining them are considered. The results of studies of the parameters of the working conditions of the considered professions of foundry workers in comparison with the standard values are presented. It has been established that in a comprehensive assessment of the working conditions of foundries working in the department of financial operations, it is necessary to take into account the duration of stay at the working equipment, the equipment and hand tools used, the type of alloy being smelted (steel, cast iron, non‑ferrous metals) and the nature of production.