Розвиток виробництва лиття з синтетичного чавуну

• Дата: 2023
• Автор: Сіренко, К. А.
• Формат: Стаття
• Мова: Українська
• Опубліковано: Physico-technological Institute of Metals and Alloys 2023
• Теми: ливарне виробництво; синтетичний чавун; стандартизація; технологія; удосконалення; промислова політика
• Онлайн доступ: https://www.metalsandcasting.com/index.php/mcu/article/view/77
• Назва журналу: Metal and Casting of Ukraine

Trends and prospects of equipment development, production technology, assortment of products made of synthetic cast iron are analyzed. In the structure of foundry production in Ukraine, synthetic cast iron occupies a significant segment in terms of volume and range of high-quality castings, including brake pads of railway rolling stock and pipeline fittings. The advantages and disadvantages of the process of manufacturing cast iron from synthetic cast iron are considered. An indicator of the quality of synthetic cast iron is the low level of its contamination by non-metallic inclusions in compliance with strict requirements for the structure and mechanical properties of the finished foundry. The regularities of the influence of smelting temperature regimes on non-metallic inclusions in synthetic cast iron are established. The technology of manufacturing high-strength synthetic cast iron, as well as cast iron with spherical graphite in its microstructure allows to optimize the modes of foundry production. It is shown that in synthetic cast iron, intended for the manufacture of thin-walled bodies of rotation, the size and shape of spherical graphite in its microstructure are of particular importance, that are reflected in the mechanical properties of the material. The level of mechanical properties of synthetic cast iron is close to similar indicators of alloy steel. Innovative technologies of electric melting of synthetic cast iron for special purposes allow to obtain regulated types of graphite inclusions, which affect both the ductility and strength of the metal. Problems have been identified that hinder the expansion of production of synthetic cast iron. Despite the difficulty of manufacturing thin-walled body castings from high-strength synthetic cast iron, this segment of foundry production has prospects for expansion. The directions of development of theoretical bases of technology of production of high-quality foundry production from synthetic cast iron are offered. Analysis of the quality of synthetic cast iron products smelted at Ukrainian foundries shows that the traditional technology of manufacturing complex products needs to be improved by strengthening the requirements for incoming control of the chemical composition of charge materials, especially scrap metal. Meticulous sorting of scrap metal and stabilization of its chemical composition is a problematic, difficult to implement, but relevant technological task for current production. Diversification of ferroalloys used in the smelting of synthetic cast iron in electric induction furnaces creates the preconditions for reducing its contamination by harmful non-metallic inclusions and increasing the yield. As a result, it provides opportunities to reduce metal costs and save electricity. In order to increase the technical and economic indicators of production and stabilize the quality of synthetic cast iron products, special research is needed in the probabilistic aspect regarding the influence of the parameters of the multicomponent through smelting technology of cast iron of different assortment. It is necessary to use methods of mathematical analysis and statistics to analyze arrays of hundreds of melts in order to establish the influence of the ratios of chemical elements in synthetic cast iron on its structure and mechanical properties, which are guaranteed to meet regulatory requirements for finished products. One of the most important ways to reduce the cost of smelting of synthetic cast iron is to reduce the specific consumption of cost ferroalloys and alloying elements by working on the lower allowable values of the chemical composition of cast iron. Despite the fact that the main parameters of the technology of manufacturing castings from synthetic cast iron are substantiated in general by the results of theoretical and experimental studies, an urgent task for manufacturers is the implementation of scientific developments in industrial practice to optimize foundry processes. In the manufacture of mass products of foundry production, such as pipeline fittings and brake pads for railway rolling stock, it is necessary to optimize and master in the industry materialenergy modes of smelting of synthetic cast iron in modern electric induction furnaces. The results of research performed at the Physico-technological Institute of Metals and Alloys of the National Academy of Sciences of Ukraine show the effectiveness of using partially graphitized synthetic cast iron for the manufacture of brake pads for railway rolling stock. Large-scale implementation of developed technological solutions in industrial practice is delayed. The generally recognized and scientifically substantiated technology of synthetic cast iron smelting for the production of, in particular, brake pads, must be adapted to the production conditions of specific foundries, as the casting technology at each plant has its nuances and specifics. Recommendations for improving the standards for brake pads made of synthetic cast iron for rolling stock are provided. A promising area of expanding the scope of use of synthetic cast iron in foundry production is the manufacture of products from high-strength and partially graphitized cast iron. To ensure increased performance of brake pads made of synthetic cast iron, it is advisable to increase the requirements of standards and specifications for these products, which in general is to optimize the content of carbon, manganese, silicon and reduce the allowable ranges of sulfur and phosphorus. The need to implement measures at the state level to protect domestic producers of relevant foundries was emphasized. Manufacturers of synthetic cast iron need to expand the range of products and exports. Foundries need to not only declare this thesis, but also put it into practice. For its part, the state is obliged to create appropriate conditions and incentives for producers. At the state level, insufficient attention is paid to strengthening the competitive position of Ukrainian foundries in domestic and foreign markets. State regulation of market relations between producers and consumers of synthetic cast iron products is a necessary and mandatory measure to create conditions capable of ensuring the stability of the foundry subsector of the industrial complex of Ukraine regardless of price fluctuations and demand for its products and possible destabilization of the global financial and economic system.