Центральноукраїнський науковий вісник. Технічні науки.
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Ідентифікатор медіа: R30-03350 (рішення Національної ради України від 25.04.2024 р. № 1418).
ISSN 2664-262X (p)
DOI: 10.32515/2664-262X
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Item Дослідження та порівняльний аналіз зносостійкості литих мелючих тіл з хромистих чавунів(ЦНТУ, 2022) Ломакін, В. М.; Кропівний, В. М.; Пукалов, В. В.; Кропівна, А. В.; Молокост, Л. А.; Lomakin, V.; Kropivnyi, V.; Pukalov, V.; Kropivna, O.; Molokost, L.Випробувано мелючі тіла, відлиті з хромистого чавуну в багатомісному кокілі, на ударно- абразивну зносостійкість і ударостійкість. Для дослідження прийнято три типи хромистих чавунів: низькохромистий (~1% Cr), середньохромистий (до 5% Cr) і високохромистий (ВХБЧ, до 20% Cr). Досліджено макро- і мікроструктуру зазначених сплавів, як матеріалу литих мелючих куль. Встановлено підвищення ударно-абразивної зносостійкості і ударостійкості таких виробів при збільшенні масової частки хрому в чавуні за рахунок утворення в металевій основі карбідів типу (Fe, Cr)3C і особливо (Fe, Cr)7C3. Економічно обґрунтовано в якості матеріалу мелючих куль низькохромистий білий чавун. A study was made of the impact-abrasive wear resistance and impact resistance of grinding bodies cast in a multi-place mold. Three types of chromium cast irons were adopted for the study: low chromium (~1% Cr), medium chromium (up to 5% Cr) and high chromium (up to 20% Cr). The macro- and microstructure of these alloys as a material for cast grinding balls has been studied. Installed an increase in the impact-abrasive wear resistance and impact resistance of such products with an increase in the mass fraction of chromium in cast iron due to the formation of carbides of the (Fe, Cr)3C and especially (Fe, Cr)7C3. Balls were cast in multi-seat chill molds. Cast iron was smelted in a medium-frequency induction furnace, such as IChT, with the main lining on a charge of pure pig iron and steel low-carbon scrap. The temperature of cast iron production was 1500 °C. Liquid cast iron was subjected to alloying with medium carbon ferrochrome. The wear resistance of cast irons was determined on samples cut from balls in the radial direction. The tests were performed in a laboratory mill When tested for impact resistance, the grinding ball received a striking blow of mass 50 kg, falling from a height of 0,5 m. The frequency of application of dynamic loads was 10 beats per minute. Impact resistance was determined by the average number of impacts sustained by the grinding body prior to destruction. Nevertheless, significant excess of the cost high-chromium over low-chromium cast iron forces us to agree with the opinion of the majority of researchers and the practice of production of such metal products. In today's conditions, low-chromium white cast iron is an economically viable material for grinding media.Item Пропускна спроможність і вантажопідйомність кузовних машин для внесення твердих органічних добрив(ЦНТУ, 2021) Лімонт, А. С.; Ломакін, В. О.; Лімонт, З. А.; Limont, A.; Lomakin, V.; Limont, Z.Мета дослідження полягала у визначенні і дослідженні пропускної спроможності кузовних машин для внесення твердих органічних добрив залежно від вантажопідйомності цих машин. Методика дослідження базувалася на використанні основних засад кореляційно-регресійного аналізу. Залежно від вантажопідйомності машин зміна їх пропускної спроможності описується рівнянням сповільнено зростаючої степеневої функції з визначеними коефіцієнтом кореляції і кореляційним відношенням пропускної спроможності машин на їх вантажопідйомність. Solid organic fertilization of soil proves one of the most important factors which contributes to increasing the yielding capacity of farm crops and improving their production qualities. Along with other means of mechanization body machines are used for the mechanized fertilization of soil through distributing fertilizers along the field surface. The paper is aimed at determining and investigating the carrying capacity of body machines used for applying solid organic fertilizers depending on their load-carrying capacity. The research technique lies in the comparative analysis of the determined resultative and factorial characters on the basis of the information obtained from the enterprises wlurh produce body machines. The information was chosen from the catologues of farm machinery and folders of the corresponding enterprises that produce tluse machines. The carrying capacity of machines was determined as the second-by-second advance of fertilizers in mass units (kilograms) to working parts of spreaders through the corresponding calculations; and the processing of harvesting and calculated data was carried out on the principles of the correlation and regression analysis, as wele as with the use of standard computer programs. The volume of statistical sampling amounted to 43 pairs of the investigated characters. The above has made it possible to estaflish. The positive correlation link between the carrying capacity of machines and their load-carrying capacity with the correlation coefficient amounting to 0.647 according to the correlation link of the resultative character on the factorial one, which equals 0.671. To ultimately determine the character of the relation between the investigated characters the authors accomplished the beveling of statistical data related to the carrying capacity of machines depending on their load-carrying capacity in the form of equations with straight line with positive angular coefficient and a number of curved lincar dependences. With iespeet to R2-coefficient the best correlation with experimental data was achieved through their approximation by means of equations of slow increasing step function. Of the investigated change is presented by the equation of the increasing hyperbola (R2=0.820), then according to the hyperbola asymptote with the load-carrying capacity increase of more than 20 tons their carrying capacity can amount to the marginal value of 25 kg/ses. The investigated dependences have to be taken into account when designing body machines used for applying solid organic fertilizers, as well as when using them for soil fertilization under the technological processes of mechanized growing of farm crops.Item Автоматизація порційної розливки розплаву чавуну в кокіль при виробництві виливків деталей машин гірничорудної промисловості(ЦНТУ, 2020) Ломакін, В. М.; Пукалов, В. В.; Дубодєлов, В. І.; Горюк, М. С.; Lomakin, V.; Pukalov, V.; Dubodelov, V.; Goryuk, M.; Ломакин, В. Н.; Дубоделов, В. И.Виконано аналіз основних параметрів дозування розплаву чавуну в металеві форми за допомогою магнітодинамічної установки МДН-6Ч. Розроблено принципову схему управління електромагнітними системами агрегату. Відпрацьовано технологію дозування і заливки металу в кокіль при виготовленні чавунних куль діаметром 40 і 120 мм. The analysis of the basic parameters of the dosage of molten iron in metal forms using the magnetodynamic installation MDN-6CH. A schematic diagram has been developed for controlling the electromagnetic systems of the unit. The technology of dosing and pouring metal into the chill mold has been developed in the manufacture of cast iron balls with a diameter of 40 and 120 mm. At the optimal casting temperature, the electrical parameters of the inductor (voltage Ui, current Ii, power Ri) were in the range Ui = 250-300 V, Ii = 480-520 A, Ri = 140-160 kW. When reducing the mass of metal in the crucible MDN-6CH using a control scheme made switching inductor from a voltage of 300 V to 250 V. The power was reduced by 15-20 kW, and the temperature of the metal remained within the tolerance of the technology of metal casting. Using the adopted dosing scheme, it became possible to cast metal at constant parameters of the electromagnetic system and the time of pouring. The technology of dispensing and pouring metal into the mold for the production of cast iron balls with a diameter of 40 and 120 mm was carried out at an inductor voltage of 300 V, and the electromagnet - 220 V. The initial level of metal on the drain socket was equal to 20 mm. The molding time of molds in the manufacture of balls with a diameter of 40 mm was 7.3 s, and balls with a diameter of 120 mm - 16.2 s. The operating time of the electromechanical actuator was set in the manufacture of balls with a diameter of 40 mm - 0.35 s, and balls with a diameter of 120 mm - 0.75s. The consumption of metal in the manufacture of balls with a diameter of 40 and 120 mm was in the range of 0.7-0.75 kg / s and 1.65-1.70 kg / s, respectively. The metal casting was carried out at temperatures of 1320-1340 ° C and 1360-1380 ° C. The dosage accuracy was determined by weighing the metal of the poured balls and the molding system of the mold. Mathematical processing of the results of the dosing showed that in the manufacture of balls with a diameter of 40 mm at a temperature of 1320 °C the error of dosing is 10-11%. With increasing iron temperature, the dosage error decreases and at a metal temperature of 1370 °C is 5-6%. In the manufacture of balls with a diameter of 120 mm at a temperature of iron 1330, the dosage error is 7-8%, and at a temperature of 1360 ° C - 3-4%. The study of the characteristics of the casting and dosing process of cast iron in the chill mold allowed us to develop the technology of casting cast iron melts, which provided the required metering accuracy and high productivity of the conveyor production of grinding bodies. Проведен анализ основных параметров дозирования расплава чугуна в металлические формы с помощью магнитодинамической установки МДН-6Ч. Разработана принципиальная схема управлення электромагнитными системами агрегата. Отработана технология дозирования и заливки металла в кокиль при изготовлении чугунных шаров диаметром 40 и 120 мм.Item Ударостійкий чавун для молольних тіл(ЦНТУ, 2020) Ломакін, В. М.; Молокост, Л. А.; Lomakin, V.; Molokost, L.; Ломакин, В. Н.Проведено дослідження динамічної міцності (ударостійкості) молольних тіл, відлитих з низькохромистого чавуну в багатомісному кокілі, в залежності від вмісту хрому в сплаві. Встановлено підвищення ударостійкості виливків куль при збільшенні масової частки хрому в чавуні в межах до 1%. При цьому найбільше зростання динамічної міцності спостерігається при збільшенні масової частки хрому від 0,3% до 0,5%. При подальшому зростанні вмісту хрому ударостійкість білого низьколегованого чавуну підвищується менш помітно і при вмісту хрому 0,7-0,8% досягає максимуму. A study of the dynamic strength (impact resistance) of grinding bodies cast from low-chromium cast iron in a multi-seat chill mold depending on the chromium content in the alloy is carried out. As a starting point, cast iron of the following composition was used: carbon – 3,0%, silicon – 1,6%, manganese – 0,4%, sulfur – 0,05%, phosphorus – 0,06%. For the study, several batches of balls with a diameter of 60 mm were cast with different chromium content in cast iron, from 0 to 1%. Cast iron was smelted in a mediumfrequency induction furnace, such as IChT, with the main lining on a charge of pure pig iron and steel low-carbon scrap. The temperature of cast iron production was 1500 °C. Liquid cast iron was subjected to alloying with medium carbon ferrochrome. Balls were cast in multi-seat chill molds. When tested for impact resistance, the grinding ball received a striking blow of mass 50 kg, falling from a height of 0,5 m. The frequency of application of dynamic loads was 10 beats per minute. Impact resistance was determined by the average number of impacts sustained by the grinding body prior to destruction. An increase in the impact resistance of ball castings has been established with an increase in the mass fraction of chromium in cast iron up to 1%. Moreover, the greatest increase in dynamic strength is observed with an increase in the mass fraction of chromium from 0,3% to 0,5%. With a further increase in the chromium content, the impact resistance of white low-alloy cast iron increases less noticeably, and in the presence of chromium 0,7-0,8% reaches a maximum. The difference in hardness from the surface (~ 52 HRC) to the center of the ball (~ 42 HRC) is a value of about 10 units. The established impact resistance of grinding bodies made it possible to conclude: when grinding solid rocks with high content of solid quartz, the use of low chromium cast iron as a material for grinding media is the most effective, as in terms of achieve high impact resistance, and to ensure cost-effective performance. Проведено исследование динамической прочности (ударостойкости) мелющих тел, отлитых из низкохромистого чугуна в многоместном кокиле, в зависимости от содержания хрома в сплаве. Установлено повышение ударостойкости отливок шаров при увеличении массовой доли хрома в чугуне в пределах до 1%. При этом наибольший рост динамической прочности наблюдается при увеличении массовой доли хрома от 0,3% до 0,5%. При дальнейшем росте содержания хрома ударостойкость белого низколегированного чугуна повышается менее заметно, и при наличии хрома 0,7-0,8% достигает максимума.