A nanostructural mechanism for recrystallization of carbon steels has been developed. First, structure‑forming nanocrystals of austenite, ferrite and cementite are formed from elementary nanocrystals of iron and graphite, free iron and carbon atoms. The crystallization centers of microcrystals of phases are formed from them. From these centers, structure‑forming nanocrystals of phases, free iron and carbon atoms, microcrystals of austenite, ferrite and cementite of carbon steels are formed.

It is shown that devices in the form of a water‑cooled metal mold with a graphite lining, which is located on the upper surface of the casting close to the end of the crystallizer, can serve as an alternative to secondary water‑air cooling systems in horizontal continuous casting. The effectiveness of the cooling capacity of the molds was evaluated during industrial tests of the devices in the process of casting iron. It has been established that the use of water‑cooled molds allows reducing the surface temperature at vulnerable points of the casting by 20–70 °C, increasing the average casting speed for individual billet sizes within 5–8 % almost eliminating shell breakout and eliminating the need for traditional secondary cooling systems.

The results of the experimental impact study for the mass fractions of ultra‑fine metal powders added into compositions of core mixtures on technical characteristics and physical properties of the foundry sodium silicate sand cores under influence of high temperatures during production of metal castings are presented and discussed. The dependences for technical characteristics and physical properties of the cores on the mass fractions of ultra‑fine powders based on aluminum, steel, and bronze are established. The significant reserves for improving a knocking‑out ability of the cores based on promising compositions for cast iron by adding ultra‑fine powders of aluminum or bronze into core mixtures are revealed. It is established that the best knockingout ability of the cores in combination with a low outgassing rate and a high gas permeability can be achieved by combining 15.0 wt. % crushed seashell and 0.5–1.0 wt. % aluminum powder. The boundaries for reasonable use of a recycled mixture in preparation of a core mixture are determined.

The article presents a list of defects in castings formed during high‑pressure casting. It has been established that each cause that creates conditions for the formation of specific defects in castings is interconnected with the incorrect setting of specific casting technological parameters. Measures to prevent the formation of defects have been determined depending on the casting technological parameters, operating modes of the mold, application of release lubricant, and alloy preparation. To ensure high quality of produced castings, it is necessary to minimize the influence of the human factor during the casting process. This can be achieved by using modern foundry equipment, high‑quality charge and auxiliary materials, and by applying automated high‑pressure casting complexes in serial and mass production.

It is shown that the main modifying intermetallides of primary microcrystals of aluminum alloys do not satisfy the principle of structural and dimensional correspondence. Nonmetallic inclusions and intermetallides cannot be centers of crystallization of metallic melts. These centers are nanostructured formations formed from structure‑forming nanocrystals of crystallizing microcrystals of phases and free atoms of alloy components. Such crystallization centers of metal melts satisfy the principle of structural and dimensional correspondence. The main mechanism of action of casting alloy modifiers is a significant decrease in the concentration of surfactants, which reduce the concentration of crystallization centers of metal melts.

The analysis of the application of various cooling mixtures in metallurgy is given. The dangerous and harmful production factors when using cooling mixtures are outlined. Characteristic and recommendations for the use of the most well‑known cooling mixtures ALTIBIO are provided.

The article presents the results of research on the development and mastery of the technological process of rolling reinforcement in coils with a nominal diameter of 6 mm of strength class A500C of a double‑sided periodic profile of the 2f form, ensuring the required mechanical properties, improving complex quality indicators based on improving the chemical composition and technological modes of two‑stage cooling on the Stelmor line taking into account its cooling and transporting abilities. A method of hot rolling of reinforcement with a double‑sided crescent (2f) profile is proposed; technological factors influencing the strength, plastic and operational properties of reinforcing bars through the formation of its effective microstructure are considered. The chemical composition of steel was proposed and modes of thermomechanical hardening of reinforcement with rolling heating were developed, providing high consumer properties. The results of mechanical tests of rolled reinforcing bars in coils and comparative data on the mechanical properties and geometric parameters of the reinforcement are also presented.

The task of modern science and technology is to develop new and improve the characteristics of already used materials for the production of competitive products. Due to the reorientation of sales markets and the search for alternative suppliers of carbide tools, OJSC “BSW – Management Company of “BMK” Holding” began cooperation with Chinese firms‑manufacturers/ suppliers of carbide blanks. The article examines the features of the microstructure of carbide blanks. The blanks differ from the serially used blanks in microstructure, in particular, in the class of tungsten carbide grain. This is explained by the fact that grades of alloy with nanoscale tungsten carbide grain are used for the production of blanks to achieve the necessary durability during operation. The features in the microstructure of the hard alloy also led to changes in the “density” parameter towards reduction, which is also inherent in all Chinese blanks and does not affect their operational properties. Inhibitors of grain growth – transition metal carbides, for example, VC, Cr₂C₃, NbC, TaC are added to hard alloy mixtures to prevent grain growth during sintering. Recently, there has been a trend towards introducing TaC + TiC additives into WC–Co alloys, which prevent grain growth and have a negligible effect on all other properties of hard alloys.

The relative narrowing of the heat‑treated pearlite steel billet characterizes the overall level of plastic and technological properties of the cold‑formed wire with large total compressions. The reduction of the interplate distance during heat treatment and during plastic deformation is increased, and the loss during repeated drawing of the plate structure with an increase in the density of dislocations inside the cells in ferrite and an additional decrease in the mobility of dislocations when they are blocked by carbon atoms during the decay of cementite reduce the plasticity of cold‑formed pearlite steel.

The paper presents an analysis of the methodology for calculating the parameters of hot‑rolled low‑carbon steel strip on a 1600 wide strip mill. Based on the analysis, a computer program for quick calculation of rolling parameters has been developed. A solid‑state model was constructed and the rolling process was simulated in the QForm environment. A comparative analysis was carried out with the passport data of the “Danieli” unit based on the modeling results. The obtained modeling results do not exceed the maximum allowable deviations for rolling force and geometric parameters of the hot‑rolled strip.

An increase in the relative elongation with an increase in the ferrite grain size is due to an increase in the intensity of deformation hardening in the area of uniform deformation. An increase in the relative narrowing with a decrease in the size of the ferrite grain is associated with the predominant direction of expansion of the central crack along the axis of tension and with a decrease in the intensity of deformation hardening in the area of local deformation.

The article discusses stains from water and reagents, as well as false structures that occur on the surface of metal and alloy samples during metallographic sample preparation and etching. The appearance of such artifacts under bright‑field illumination and when using optical contrasting techniques such as dark‑field and polarized light is demonstrated.

The influence of increasing the cementation duration from 8 to 12 hours with subsequent quenching and low‑temperature tempering on the structure formation and contact fatigue of structural medium‑carbon low‑alloy steels 35CrMnSi4, 40Cr4, and 42CrMoS4, which are not traditionally cemented, was investigated. It has been confirmed that in steel 35CrMnSi4, the increased silicon content enhances the microhardness of the surface of thermally diffused‑hardened layers, reduces the amount of carbon and the thickness of the proeutectoid zone, decreases the volumetric fraction of carbide phase and inclusion sizes compared to similar layers formed on steels 40Cr4 and 42CrMoS4. It was found that the thermally hardened layers of steel 35CrMnSi4 after 12‑hour carburizing and steel 40Cr4 after 8‑hour carburizing exhibit maximum wear resistance. Their microstructure consists of tempered martensite, 10–15 vol. % of carbides with a size of less than 10 μm, and retained austenite – 10 vol. % in steel 35CrMnSi4 and 17 vol. % in steel 40Cr4. It was found that a carbon content of more than 1.8 wt. % on the surface of cemented layers leads to a decrease in wear resistance due to the high content (more than 30 vol. %) of large (more than 10 μm) carbides.

This article presents the findings of research on the impact of thermal diffusion galvanizing duration and the particle size of zinc dust waste in the galvanizing mixture on the properties and structure of the zinc coating. The study focuses on coating characteristics, such as microstructure and particle distribution.

The article presents calculations and analysis of phase equilibria in magnesium alloys of the Mg–Al–Mn–Ca system with additional alloying of Zr and La. An assessment of the influence of the degree, deformation rate, and extrusion temperature on the composition, structure, and mechanical properties of the material has been evaluated. The impact of heat treatment of deformed samples on the complex of strength and plastic properties has been investigated.

Показано, что элементарными строительными частицами фотонной материи являются отрицательный, положительный и нейтральный фотоны. Из них образуются фотонные электроны и позитроны, из которых формируются фотонные протоны и нейтроны. Последние образуют фотонные ядра. Они захватывают фотонные электроны и формируют атомы фотонной материи, из которых образуется вещественная материя, изучаемая и используемая людьми. Из фотонной материи состоит тело человека и весь вещественный мир. Элементарными строительными частицами нейтринной материи являются отрицательный, положительный и нейтральный нейтрино. Образуемые из них нейтринные электроны и позитроны формируют нейтринные протоны и нейтроны – основу нейтринного ядра. Они захватывают нейтринные электроны и формируют атомы нейтринной материи, из которых образуется духовная материя, не изучаемая людьми. Из нейтринной материи состоит душа человека и весь духовный мир. Показано, что душа человека в 10000 раз легче его тела. Нейтринная материя значительно меньше подвержена воздействию гравитации, чем фотонная материя.