This paper presents the results of a study and analysis of the effect of modifying low-chromium hypoeutectic cast iron with a new boron–barium ferroalloy on its properties—wear resistance and impact resistance—in comparison with traditional boron- and barium-containing additives. The uniqueness and novelty of the work lies in the study of the nature of changes in the structure and wear-resistant properties of low-chromium cast iron as a result of its modifying treatment with a new boron–barium ferroalloy. In a laboratory electric resistance furnace, low-chromium cast iron was melted, and four batches of prototypes were cast. Samples of the first batch, for subsequent comparison, were made without modification. When casting the remaining three batches of samples, the cast iron was modified with three different additives: ferroboron FeB12, ferrosilicobarium FeSi60Ba20, and a new complex boron–barium modifier. In order to compare the degree of effectiveness of the applied modifiers, a metallographic analysis of the structure was performed, hardness measurements were performed on the surface of the samples, and they were subjected to abrasion and cyclic shock-dynamic impact tests. In all cases, when modifying cast iron, there was an increase in hardness, a noticeable grinding of the microstructure, and a redistribution of structural components towards an increase in the proportion of perlite and finely dispersed ledeburite. A comparative analysis of the results of testing samples for dry friction and shock showed a higher surface resistance of cast samples made of modified cast iron compared to unmodified low-chromium cast iron of the same composition. A comparative study of the parameters of wear tracks and craters on damaged surfaces established that the most optimal combination of wear-resistant qualities of low-chromium cast iron occurs when it is treated with a complex boron–barium modifier, which is also evidenced by obtaining a more favorable microstructure.

This paper deals with the possibility of smelting quasi-high-entropy alloys (QHEAs) with the partial use of ferroalloys in the charge instead of pure metals. The Cantor alloy (CoCrFeMnNi) was used as the base alloy and the comparison sample, into which niobium was introduced in the amount of 14 to 18% by weight. The structure, hardness, strength, and tribological properties of prototypes were studied. The results obtained showed, on the one hand, the possibility of using ferroalloys as charge components in the smelting of QHEAs and, on the other hand, the positive effect of niobium in the amount of 14–17% on the strength and wear resistance of the alloy. Increasing the niobium content above 18% leads to its uneven distribution in the structure, consequently decreasing the strength and wear resistance of the alloy. The structure of the studied alloys is represented by a solid solution of FCC, which includes all metals, and the niobium content varies widely. In addition, the structure is represented by the phases of implementation: niobium carbide NbC 0.76–1.0, manganese carbide Mn₇C₃, and a CrNi intermetallic compound with a cubic lattice.

This work studied the effect of the amount of additives and the composition of refining slags on the metallurgical of steel grades of the S355G10, S420G2, and S460G2 types. The objects of study were samples of industrial melts after out-of furnace refining of steel with different amounts and nature of additives. Based on the results obtained, the recommended amounts of additives and the composition of the refining slag have been developed, which makes it possible to reduce the metal contamination with non-metallic inclusions.

The present work is devoted to the study of the influence of the parameters of the structural anisotropy of rolled products on the low-temperature impact strength of alloyed steels. A quantitative metallographic analysis of the microstructure of rolled steel samples obtained after testing for low-temperature toughness was carried out. It was established that the main reason for the decrease in the low-temperature impact strength of rolled steel samples is a highly developed segregation band enriched with carbon films formed at the stage of steelmaking conversion in violation of the technology of continuous casting of steel. The microstructural analysis of rolled stock samples was used in the work, and studies of the fracture surface of rolled stock samples were carried out with a scanning electron microscope using X-ray microanalysis methods. The studies carried out showed that the metallurgical quality of sheets of one heat, as well as individual samples within one sheet, varied over a wide range, from satisfactory to unacceptably low. It was established that the main reason for the decreasing low-temperature impact strength of rolled products was a highly developed segregation band enriched with carbon films, formed at the stage of steelmaking in case of violation of the continuous casting of steel technology. The multivariate statistical analysis carried out showed that only the size of the segregation band has an effect on the low-temperature impact strength of 10 mm thick rolled coil samples.

Coal combustion generates significant volumes of ash, a technogenic by-product that poses a serious threat to regional environmental sustainability (environmental chemical contamination and air pollution). This study aims to assess the feasibility of utilizing this type of ash as a raw material component in the fabrication of refractory bricks and to investigate the fundamental properties of the resulting experimental products. Ash was incorporated into the batch composition at concentrations ranging from 10% to 40% by weight, blended with clay and water, then shaped through pressing and subjected to firing at 1000 °C and 1100 °C in an air atmosphere for 2 h. After complete cooling, the samples were subjected to compressive strength testing. Samples containing 40 wt% coal ash exhibited insufficient compressive strength and were therefore excluded from subsequent investigations. For the remaining samples, apparent density, open porosity and slag resistance were determined. The microstructural characterization was performed, and the phase composition of the samples was analyzed. The results revealed that the phase composition of the experimental samples differs significantly from that of the reference sample (ShA-grade chamotte brick in accordance with GOST 390-96, currently used as lining in metallurgical furnaces across the country), exhibiting a higher mullite content and the absence of muscovite. A small amount of kaolinite was detected in the experimental samples even after a 2-h firing process. This observation may be attributed to the effect of kaolinite crystallinity on the transformation process from kaolinite to metakaolinite. The mechanical strength of the experimental samples meets the relevant standards, while slag resistance demonstrated an improvement of approximately 15%. Open porosity was found to decrease in the experimental samples. In addition, a change in the pore size distribution was observed. Notably, the proportion of pores larger than 10,000 nm was significantly reduced. These findings confirm the feasibility of incorporating coal ash as a viable raw material component in the formulation of refractory materials.

Improving wear resistance of elements of mining and processing equipment, subjected to abrasion and shock loads, is an actual task, since it determines effectiveness of mining operations to a great extent. Results of industrial tests of two kinds of mining and processing equipment details, manufactured of pilot wear-resistant alloys, presented. Two sidepieces plates for jaw crushers were manufactured of steel based on 30Х3МФ grade and additionally alloyed by niobium (up to 0.15%) as a strong carbide-forming element. As a comparing sample, steel 30Х3МФ without additional alloying was used. The second kind of details to test – sprockets, used as grinding bodies in the crushers for medium ore crushing. The sprockets were casted of chromic iron with increased nickel content (up to 3.5%) to increase the shock ductility, vanadium and titanium content (together up to 1.5%) – to form carbides of MeC type at decreased chrome content (down to 16%). As the comparing sample sprockets ware used, casted of ИХЧ28 grade iron, which is used for these purposes at present. The tests were accomplished at the operating equipment during medium crushing and grinding of “Bogach” deposit ore. The test cycles corresponded to the accepted at the plants crushing cycles – 18 h. The tests were duplicated 2 times. After tests completion the percent of wear of pilot samples was evaluated. The wear was evaluated by relative mass change. The results obtained showed, that the pilot samples have higher wear resistance approximately by 30%.