Requirements Of Documentation Research Articles

ВЛИЯНИЕ СТРУКТУРООБРАЗУЮЩИХ РЕЦЕПТУРНЫХ ИНГРЕДИЕНТОВ И ПОДСЛАСТИТЕЛЕЙ НА КАЧЕСТВО СУФЛЕ ИЗ ЯБЛОК

This article theoretically and experimentally proves the expediency of replacing apple puree of the trademark with mashed fresh apples in souffle technology, as well as the use of food agar as a stabilizer, and natural honey as a sweetener. According to the results of organoleptic indicators, an improvement in the consistency of the finished product is observed, the souffle structure becomes more dense and porous. The color of the product changes from gray to milky cream, that increases the consumer quality of the products. In terms of physico-chemical and microbiological parameters, the souffle meets the requirements of regulatory and technical documentation and TR CU 021/2011. Due to the natural proteins in natural honey, there is an improvement in the foaming ability of the souffle, and the foam is characterized by a denser and more stable structure. In addition, with the addition of natural honey, the viscosity of the product increases, which indicates its stabilizing properties.

ПОРІВНЯЛЬНА ОЦІНКА ЯКОСТІ СОНЯШНИКОВОЇ ОЛІЇ

Comparative assessment enables consumers to make an informed choice and use high-quality and safe sunflower oil, which has a positive effect on their health and economic well-being. Vegetable oils, especially sunflower, are a popular source of dietary fat in economically developed countries, promoting heart and brain health. They contain essential fatty acids useful for cell growth and brain development. Sunflower oil is also the most widespread type of vegetable oil in Ukraine. A healthy lifestyle requires quality food. The issue ofassessing the quality of sunflower oil is timely and relevant. The purpose of our research was to assess the quality of sunflower oil samples of leading producers in accordance with the requirements of current regulatory documentation and the declared labeling.Based on the survey, it was determined which types of sunflower oil are preferred by consumers. These samples were chosen as research objects. At the first stage of the research, the appearance of the package and the quality of the information provided on the label were evaluated. Then the quality of the samples was assessed according to organoleptic and physicochemical parameters.The assessment of the labeling and quality of sunflower oil showed that the information on the labels meets the requirements for mandatory information about the food product.The organoleptic characteristics of the oil samples meet the requirements of the State Standard of Ukraine 4492 "Sunflower oil. Specifications".Some samples have an increased moistureand volatile content, which can affect the stability and quality of the product during storage. However, the iodine value of all samples is within acceptable limits. Acid and peroxide numbers also do not exceed the established norms. The results of the research can be useful both for consumers when choosing high-quality oil, and for producers in order to improve product quality.

ВЕТЕРИНАРНО-САНИТАРНАЯ ОЦЕНКА КАЧЕСТВА СЫРОГО МОЛОКА ПО ЖИРНОКИСЛОТНОМУ СОСТАВУ И СОМО

The results of a veterinary and sanitary assessment of raw milk are presented in terms of dry skimmed milk residue (SMR) and fatty acid composition (FAC). To determine the fatty acid composition, the method of gas chromatography with flame ionization detection (GC-FID) was used; SOMO was determined by calculation, with a preliminary determination of the mass fraction of dry matter and the mass fraction of fat. A total of 30 samples of raw cow's milk from private farms in the Republic of Tatarstan were examined. It was found that in the case of 56,6% of samples, the SOMO indicator did not meet the requirements of regulatory documentation (it was lower than the standardized value by 2,4 - 45,1%). In terms of FAC deviations from the established requirements were detected in four samples. At the same time, the strongest discrepancies from the established range were noted for butyric, myristic, palmitic, stearic, oleic and linoleic acids.

The use of a biopeptide with antiviral properties as a functional ingredient for ice cream

Biopeptides are used in food products to give them a functional orientation. The purpose of the study is to characterize and use a biopeptide with antiviral properties for the production of ice cream with functional purpose. The molecular mass distribution of the peptide was evaluated by mass spectrometry and identified by MALDI-TOF and MS mass spectrometry on the MALDI-time-of-flight Ultraflex mass spectrometer (Bruker, Germany). The mass spectra were analyzed using the Mascot program, the Peptide Fingerprint option (Matrix Science, USA) using the Protein NCBI database. The antiviral activity of the peptide was studied on lentiviral particles. The assessment of the physical-chemical parameters of ice cream enriched with a biopeptide was determined according to regulatory documents. As a result of the research, a characteristic of a peptide with antiviral properties is given. It has been established that the peptide consists of 8 amino acids and is classified as an alpha helical cationic antiviral peptide. Ice cream “Vanilla Ice cream 15%” has been developed using synthesized LREGIKNK peptide as a functional ingredient. It is shown that the ice cream meets the requirements of regulatory documentation.

Математическое моделирование упрочняющей термической обработки винтовых пружин подвижного состава

The article is devoted to the optimization of the quenching and tempering modes of 60C2 spring steel based on the application of the theory of planning an engineering experiment. The relevance of the work is confirmed by measurements of the hardness of the steel of the screw springs of railway cars, which does not meet the requirements of regulatory and technical documentation. Thus, the need to clarify the values of quenching and tempering temperatures in the manufacture of springs is justified. An experiment was conducted that allowed us to obtain a mathematical model in the form of a second-order regression equation for predicting hardness depending on the tempering and tempering temperatures of steel and to establish the optimal values of these parameters to achieve the required hardness of 40-46,5 HRС according to GOST 1452-2011.

Оценка трансмиссионных масел, применяемых при эксплуатации гидромеханических коробок передач автобусов

The article has considered the problem of the frequency of replacement for transmission oils in the hydromechanical gearboxes of buses with the terms of technological work regulated by the manufacturer. The established deadlines have a negative impact on the operational reliability, efficiency and economy of buses in urban conditions. The main indicators of the physico-chemical properties of transmission oils used in the operation of hydromechanical transmission boxes of buses have been determined. The analysis of the transmission oils used in the operation of hydromechanical transmissions of buses has been carried out. The requirements of the technical documentation for the operation of hydromechanical transmissions of buses have been considered. The list of considered technical documentation for hydromechanical transmissions of buses has been summarized. The laboratory tests results of the main indicators for the physico-chemical properties of fresh transmission oils used at the automobile transport enterprise have been used to evaluate the obtained data. The results have been confirmed by the protocols of the testing center of the branch of JSC «SZHS Vostok Limited» (St. Petersburg). The key graphs of the main indicators have been presented physico-chemical properties of the analyzed oils and a comparative graph of the infrared spectra of the oils under consideration. The scientific and technical groundwork has been outlined for further promising research in this area.

Study of safety and quality indicators of cereals and legumes in the southern part of Russia

The objects of the study were wheat, corn and soybean samples. We carried out studies to determine the quality indicators, as well as the content of grain impurities and insect infestation of the studied samples of the Krasnodar Territory and the Rostov Region. It was determined that the fiber content in the wheat is quite high. It was revealed that the content of pesticides and mycotoxins in wheat, corn and soybean crops are safe food raw materials. Harmful impurities were found in the crops, which indicates that the conditions for growing, processing, transporting and storing grain and leguminous crops are correct. Every safety index at the objects under investigation complies with the requirements of the regulatory documentation.

Анализ и обобщение действующих требований по проектированию систем газораспределения в контексте оценки возможности автоматизации составных частей процесса построения оптимальной трассы газопровода

The paper provides an analysis of the complex problems of existing gas distribution networks. The current requirements of regulatory documentation for the stage of designing gas distribution networks are summarized and investigated, and a typical scheme of gas distribution networks is presented that meets the current requirements of the law. The main ways and principles of automation of the design processes of individual parts of gas distribution networks are given. The paper touches upon the shortcomings of the existing requirements for the development of gas supply schemes, the presence of which reduces the safety of existing gas networks and the rate of gasification of consumers, and contributes to the formation of the problem of the lack of technical feasibility of connecting a part of prospective consumers. The results of the study allow us to identify the main problems of existing gas networks, the imperfections of the current legislation and ways to solve problems to improve reliability, safety and optimize the economic component of the development of gas distribution systems.

Determination of the Anti-Escherichial Activity of the Pyrimidine Derivative 3-[2-[(4,6-dimethylpyrimidin-2- yl)amino]-2-oxoethyl]quinazolin-4(3H)-one

The aim of this study was to investigate the antimicrobial activity of the pyrimidine derivative 3-[2-[(4,6-dimethylpyrimidin-2-yl)amino]-2-oxoethyl]quinazolin-4(3H)-one against Escherichia coli. The study of antimicrobial activity was carried out in vitro by serial dilutions of the pyrimidine compound, followed by determination of the minimum inhibitory concentration of 3-[2-[(4,6-dimethylpyrimidin-2-yl)amino]-2-oxoethyl]quinazolin-4(3n)-one (VMA-13-14) and in vivo on the model of generalized E.coli infection. The study of antimicrobial activity in vivo was carried out on 40 CBA mice weighing 19–20 g. All manipulations with animals were performed in accordance with the requirements of the regulatory documentation governing the maintenance of laboratory animals and work involving them. The antimicrobial activity of the pyrimidine compound 3-[2-[(4,6-dimethylpyrimidin-2-yl)amino]-2-oxoethyl]quinazolin-4(3H)-one against E.coli in vitro was evaluated in terms of mouse survival, contamination of blood and internal organs (liver, spleen, lungs, brain), as well as the total number of leukocytes and leukograms. The experiment determined that the pyrimidine compound 3-[2-[(4,6-di- methylpyrimidin-2-yl)amino]-2-oxoethyl]quinazolin-4(3n)-one demonstrates antimicrobial activity against E.coli: in vitro, it has a bactericidal effect at a concentration of 128 µg/ml; in vivo, it has an antimicrobial effect in conditions of generalized infection with the introduction of 50 mg/kg/day for 10 days. The antimicrobial effect of 3-[2-[(4,6-dimethylpyrimidin-2- yl)amino]-2-oxoethyl]quinazolin-4(3n)-one is comparable to ceftazidime, which is the drug of choice in the treatment of E.coli infection.

Improving concrete quality for transport construction

The creation of a transport network with high performance characteristics of the roadbed is an urgent task in the field of road construction. Foreign practice in the construction and operation of such facilities indicates the need for research studies aimed at obtaining an optimal concrete stone structure by optimizing the concrete composition (controlling the concrete mixture properties at the microlevel) and using state-of-the-art complex additives. The technological properties of concrete mixture and concrete were studied in accordance with the requirements of the current regulatory documentation using verified equipment. The compressive strength of concrete was determined using an MS2000 testing machine (with a measuring range of up to 2000 kN and a loading error of no more than 1%). The abrasion level was estimated by the loss of the sample mass during operation of an LKI-3 device (abrasion disc). The mass water absorption was determined by variations in the sample mass during water saturation. The article presents the physical and mechanical characteristics of heavy concrete (strength, abrasion, water absorption) obtained using TechniFlow-61, TechniFlow-178 PRO, and PowerFlow-3100 additives. The results indicate the positive effect of the above additives, which can be used to decrease the water-cement ratio for obtaining concrete mixtures of a given mobility, produce concretes of a denser structure, and reduce the number of open pores. The conclusion is made about the effectiveness of new-generation additives with plasticizing and water-reducing agents for improving the technological properties of concrete mixtures, as well as the physical and mechanical characteristics of the resultant concretes.

Producing plant-supplemented oat-based beverages

Oat grain is characterized by the presence of a number of biologically active substances that contribute to the normalization of the gastrointestinal tract and maintain vascular health. Oat grains are used in diet food as they do not contain gluten. The germination of oat grains contributes to increasing the content of biologically active substances in it. The proposed method for producing cereal drinks based on oats includes the stages of washing the grains, disinfecting, germinating the grains, obtaining a liquid grain base, stabilizing the structure of the grain base, sterilization, adding flavoring components. The developed technology makes it possible to produce oat-based cereal drinks with a stable structure and improved organoleptic characteristics without additives and with vegetable additives, which are dried chokeberry meal (2 %) and rosehip syrup (16 %). The organoleptic characteristics of the drinks obtained correspond to the requirements of regulatory documentation. Drinks with herbal additives are superior to drinks without additives in taste, aroma, color and texture. The storage capacity of drinks established in the course of microbiological examination and analysis of viscosity and acidity is five days.

Theoretical and methodological foundations for forensic commodity examination of garment products

The examination of garment products is a popular type of forensic commodity expertise in proceedings related to the protection of the interests of Ukrainian producers, business entities in the sale and rental of garment products, as well as the investigation of offences related to export and import operations.
 Based on the study of the legislative framework for conducting forensic commodity research of garment products, as well as regulatory documents on the methodology for assessing the quality of garments for various purposes, the author states that there is still no unified list of control objects to be studied in the course of garment examination.
 The article is devoted to the problems of methodology for forensic commodity examination of garments. It has been established that the lack of unified terminology causes differences in the interpretation of methodological guidelines for conducting examinations and differences in the interpretation of research results. The fundamental differences between the purpose, composition of materials and market conditions of a particular type of garment can significantly affect the choice of research methods. In this regard, the article considers the nomenclature of objects of forensic commodity examination of garments, which makes it possible to streamline the expert’s actions in accordance with the specifics of the object of study. The nomenclature identifies the following groups of indicators for the examination of garments: compliance of the product and control label details with the requirements of regulatory documentation, correspondence of appearance, adequacy of the type of materials used for sewing the garment, safety of materials, quality of fit of the garment, quality of manufacture of the garment, correspondence of linear measurements to nominal values, and market value of identical (similar) goods.

Инновационные технологии повышения производительности и качества механической обработки полимерных композиционных материалов

An urgent problem for improving the efficiency and machining operation quality for new polymer composite materials (PCM) based on carbon fiber in the operation of rocket and space equipment and aircraft engineering parts is solved in the article. One of the breakthroughs of the Russian domestic engineering is the introduction of wing elements of the new MS-21 civil airliner, the production of noise suppression bodies, compressor blades and other parts of gas turbine engines made of carbon fiber, requiring high-quality and productive machining. Machining operation of these products involves difficulties caused by the requirements of the design documentation to ensure the necessary degree of roughness, soundness of the machined surface and high strength of the finish-machined component. This article presents the results of a study of the application of high-performance technology of sequential blade-abrasive processing of carbon fiber-based PCM products. This article presents the results of a study of the application of high-performance technology of sequential blade-abrasive operation of carbon fiber-based PCM products. The rational geometry of the blade cutting tool for primary machining of the PCM is determined. An adequate empirical mathematical model of cutting modes influence on the surface layer roughness in the milling operation has been developed, as well as rational processing modes have been determined.
 The results of experimental studies of the abrasion of PCM with rigid grinding wheels made of white electrocorundum, green silicon carbide and elborum are presented. The dependences of the surface layer roughness on the grinding modes are given. According to the research results and the developed mathematical model, the rational characteristics of grinding wheels and processing modes are determined. For the first time, the issues of the influence of machining defects on the strength of PCM are viewed. Comparative tensile and tear strength tests of samples made by traditional edge cutting machining and sequential edge-cutting-abrasive operation are presented. The increase in tensile and tear strength of PCM parts manufactured according to the technology of sequential edge-cutting-abrasive operation by 20.30% compared to traditional edge-cutting operation has been proved.

NUMERICAL VALUES OF DEFECTIVE AND REFERENCE INDICATORS OF ERGONOMICS PROPERTIES OF SPACE OF AUXILIARY ROOMS FOR GENERAL USE OF AN APARTMENT BUILDING

In accordance with the general algorithm of the first theoretical stage, the basic principles of formulating reference, basic and defective values of indicators of urban planning quality of life properties and their categories were developed in accordance with the requirements of regulatory documentation in the field of construction and the results of expert assessments, which in turn provide the opportunity to determine numerical values and justify the characteristics deficient, reference and basic indicators of simple properties of a residential building, in particular properties of the ergonomics of the space of auxiliary premises for common use of an apartment building.
 Regulatory documentation provides for the following terms and definitions regarding product quality indicators in construction: 
 - basic indicator of product quality
 - the value of the indicator of product quality, which is taken as a basis for a comparative assessment of its quality;
 - the relative value of the product quality indicator
 - the ratio of the value of the evaluated product quality indicator to the corresponding base value indicator;
 - the regulated value of the product quality indicator
 – the value of the product quality indicator established by regulatory documentation;
 - the nominal value of the product quality indicator
 - the value of the product quality indicator, which corresponds to certain average or fixed conditions and is taken as the beginning of tolerance counting;
 - the limit value of product quality indicators
 - the maximum or minimum permissible value of the product quality indicator;
 - the optimal value of the product quality indicator
 - the value of the product quality indicator at which the greatest effect ratio is achieved to losses; - level of product quality
 - a relative characteristic of product quality, built on the comparison of the values of the quality indicators of the evaluated products with the basic values;
 - technical level of products - a relative characteristic of the quality of products, built on the comparison of the values of indicators that characterize the technical excellence of the evaluated products, with the basic values relevant indicators;
 - evaluation of the technical level of products
 - a set of operations, which includes the selection of the nomenclature of indicators that characterize the technical excellence of the evaluated products, the determination of the values of these indicators and their comparison with the basic ones;
 - defect - products, the transfer of which to the consumer is unacceptable due to the presence of defects.
 Categories and methods of determining defective, basic and reference indicators of a residential building according to the content of the relevant properties are divided into:
 - without physical units of measurement and regulation by regulatory documentation;
 - without physical units of measurement (or with complex units of measurement) regulated by regulatory documentation;
 - with physical units of measurement without regulation by regulatory documentation;
 - with physical units of measurement and regulation by regulatory documentation.
 On the basis of the analysis of regulatory documentation, documentary data and expert assessment, the numerical values and justification of the characteristics of defective, reference and basic indicators of simple properties of the ergonomics of the space of auxiliary premises for common use of an apartment building are determined.
 Further research will be focused on the determination of numerical values and the substantiation of the characteristics of the missing, reference and basic indicators of the properties of the residential area, in accordance with the developed range of properties of urban planning quality of life.

Determination of Corrosion Rate in Galvanized Pipes in Centralized Hot Water Supply Systems

To counteract possible corrosion, steel pipes are coated with a protective layer of zinc with a thickness of 20 to 85 microns, depending on the requirements of regulatory documentation. It is proven that hot-deposited zinc can effectively protect steel surfaces for 20 to 120 years. However, in centralized hot water supply (CHWS) systems, the period of protective action can decrease to two to three years, with further damage to the zinc layer and the appearance of fistulas. In order to counteract adverse factors, it is necessary to take into account the operating mode and design features of the system, the properties of the coating, and the environment in which the pipes operate. In this article, the main attention is paid to the study of the behavior of zinc coating. The protective properties and corrosion rate of zinc coating in tap water were evaluated. It was established that the protective effect of zinc is effectively manifested in the ratio of the protected area to the unprotected, as SZn/SFe ≥ 9:1. The influence of iron-containing sediment, when it accumulates in the pipes of a CHWS system, on the corrosion rate of the zinc coating was studied. It was also noted that the corrosion rates of the new zinc coating and uncoated steel pipe measured in short-term tests differed slightly.

Experience with the use of pharmacopoeial reference material for the activity of measles vaccine

Due to the increased incidence of measles in Russia and in many other regions of the world, vaccines for the measles prevention are especially in demand. Ensuring the quality of the measles vaccine for effective disease prevention is within the scope of the tasks of the state policy of our country. Evaluation of the experience of using a pharmacopoeial standard material of measles vaccine activity for measurement of the specific activity of the measles virus in vaccines with a measles component that are used in the Russian Federation for measles prevention. The object of the study was the Pharmacopoeia reference material (PRM) of the activity of the live measles vaccine of series 10. The activity of PRM was analyzed when determining the specific activity of the measles, mumps-measles and combined vaccines for the prevention of measles, rubella and mumps, as well as based on the materials of the summary protocols for the production of these vaccines. The titer of the measles virus in the PRM for each determination of the specific activity of the measles virus in vaccines in the Scientific Centre for Expert Evaluation of Medicinal Products in 2021-2022, as well as according to the summary production protocols, was within the boundaries of the certified value (4.63 ± 0.5) lgTCD50/0.5 ml, and the test results met the acceptance criteria in accordance with the requirements of regulatory documentation. During the observation period, the average value of the PRM titer (4.61 lgTCD50/0.5 ml) practically did not differ compared to the average value of the certified characteristics of the PRM, the standard deviation of the mean value of the measles virus titer in the PRM did not exceed 0.15 lgTCD50, which indicated the stability of the analytical work at the enterprise and in IC. The data obtained indicate the stable activity of PRM, the correctness of the determination of the measles virus titer in the vaccination dose of the vaccine, and the validity of the method for monitoring the specific activity of the measles virus in vaccines.

Digital transformation of standardization and quality control in construction production based on the implementation of the registry principle of managing the requirements of regulatory and technical documentation

Обеспечение качества выполнения строительно-монтажных работ традиционно является приоритетной задачей строительной отрасли, а сегодня в условиях становления цифровой экономики выступает основой формирования критериев эффективности трансформационных процессов. Статья посвящена поиску путей развития методического инструментария цифровой трансформации стандартизации и контроля выполнения строительно-монтажных работ для широкого круга участников строительства. Масштабное применение технологий информационного моделирования и цифровых моделей на всех этапах жизненного цикла объектов капитального строительства, требует радикальных изменений в организации и развитии отраслевой нормативно-технической базы обеспечения качества. Во многом повышение качества строительно-монтажных работ зависит от лояльности проектировщиков и строителей к реестровому принципу технического регулирования. Автор ориентировался на критерии повышения качества проработки технологических процессов в строительстве. Для достижения цели автор предлагает в статье к рассмотрению концепцию формирования и применения реестров нормативных требований (РНТ), призванных изменить подход к работе с нормативным документом, в том числе при оценке качества предъявляемых строительно-монтажных работ (СМР), проводимых в соответствии с данным нормативом. Применяемые РНТ предполагают иную структуру информации, где ключевым элементом является именно требование. Структура требования содержит в себе числовые параметры, формируемые для конкретных процессов.
 Концепция предполагает интеграцию реестров требований с информационной моделью здания, формирование запроса и применение выгружаемых из модели данных по перечню работ, их объемам, организационно-технологическим связям между работами и др. Реестр, с привязанными к нему формулами для оценки соответствия, рассматривается как инструмент автоматизации операционного контроля. При удовлетворении требований приемки работ формируются данные для создания цифровой исполнительной документации и наполнения цифровой исполнительной модели. Концепция развивается как одно из направлений научно-образовательной программы деятельности, реализуемой в Научно-образовательном центре «Цифровое строительство и эксплуатация» (НОЦ ЦСЭ) НИУ МГСУ в сотрудничестве с партнером АО «Кодекс».

Designing onboard cable networks components considering the manufacturability requirements

The design of the onboard cable network components of an aircraft that meet the requirements of regulatory and technical documentation is considered. The stages of the life cycle of the aircraft are noted, at which the analysis and evaluation of the technical solutions adopted at the design stage of the aircraft, aimed at adaptability to the installation and dismantling of products and components of the aircraft, take place. The scope of the design documentation required for the manufacture of onboard cable network components is determined. The peculiarity of the design stages and the inconsistency of the requirements of the regulatory and technical documentation used in designing onboard cable network components of the aircraft are indicated. A set of requirements for manufacturability, efficiency, reliability and electromagnetic compatibility of onboard cable network components is formalized. The criteria for the harness manufacturability are determined. A method is proposed for synthesizing the image of the onboard cable network components using a graph which vertices are supplemented with attributes that characterize the features of a wired connection to the elements of onboard systems. An algorithm of the designer's actions is developed when determining the need to introduce a connector into an electrical circuit, taking into account the requirements of the electromagnetic compatibility of wires. Recommendations for designers of aircraft onboard cable network components are formulated.

Analysis of the influence of the chemical composition and metallurgical quality of grinding balls on their operational properties

On the basis of a complex of researches carried out in laboratory and industrial conditions using standard methods of metallographic analysis and impact testing of balls, the regularities of the formation of the quality of the macro- and microstructure of grinding balls in relation to their operational resistance in the production of rail steels and specialized ball steels of various chemical compositions are determined. When studying samples of five different compositions, it was determined that grinding balls made of 76XF steel have an optimal homogeneous microstructure that provides high impact resistance in combination with increased hardness after heat treatment. Additional alloying of the specified rail steel with chromium and nickel in excess of the requirements of regulatory documentation leads to the formation of dendritic liquation in the cast structure, which decreases, but is not completely eliminated after heat treatment of the produced balls. This microstructure is defective and causes a reduced impact resistance of grinding balls. In the production of balls made of 90HAF grade hypereutectoid rail steel, cementite is present in the microstructure, which reduces the balls' resistance to shock loads; at the same time, there is no noticeable increase in the hardness of heat-treated balls compared to balls made of 76XF steel. With regard to balls made of specialized steels of grades Sh2.1 and Sh2.3, the determining effect on their impact resistance of macrostructure defects passing from the initial cast blanks has been established. The features of the quenching microstruc-ture of grinding balls made of specialized steels of the specified grades, formed by varying the modes of their heat treatment, does not significantly affect the impact resistance of the balls

Analysis of the influence of the chemical composition and metallurgical quality of grinding balls on their operational properties

On the basis of a complex of researches carried out in laboratory and industrial conditions using standard methods of metallographic analysis and impact testing of balls, the regularities of the formation of the quality of the macro- and microstructure of grinding balls in relation to their operational resistance in the production of rail steels and specialized ball steels of various chemical compositions are determined. When studying samples of five different compositions, it was
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 determined that grinding balls made of 76XF steel have an optimal homogeneous microstructure that provides high impact resistance in combination with increased hardness after heat treatment. Additional alloying of the specified rail steel with chromium and nickel in excess of the requirements of regulatory documentation leads to the formation of dendritic liquation in the cast structure, which decreases, but is not completely eliminated after heat treatment of the produced balls. This mi-crostructure is defective and causes a reduced impact resistance of grinding balls. In the production of balls made of 90HAF grade hypereutectoid rail steel, cementite is present in the microstructure, which reduces the balls' resistance to shock loads; at the same time, there is no noticeable increase in the hardness of heat-treated balls compared to balls made of 76XF steel. With regard to balls made of specialized steels of grades Sh2.1 and Sh2.3, the determining effect on their impact resistance of macrostructure defects passing from the initial cast blanks has been established. The features of the quenching microstruc-ture of grinding balls made of specialized steels of the specified grades, formed by varying the modes of their heat treatment, does not significantly affect the impact resistance of the balls