Results of investigations on development of high-efficient electrode and filler materials for welding and surfacing of copper and alloys on its base are considered. It is shown that increased requirements to quality of welded joints and deposited metal can be satisfied, primarily due to development of reliable welding consumables: electrode and filler wires, fluxes (fused and activating flux-pastes), as well as special coated electrodes. Arc welding and surfacing processes improved on their base provide the required level of thermophysical properties of welded joints, high strength and tightness of welds, reliable service durability in friction assemblies and corrosion media, etc. Effectiveness of new welding consumables is confirmed by their practical application in manufacture of welded crucible moulds of electrometallurgical furnaces, welding busbars, electrode holders, enlargement of hot-rolled coils for their further rolling, making various bimetal items by surfacing, etc. 10 Ref., 5 Tables. K e y w o r d s : arc welding and surfacing, copper and its alloys, electrode and filler wires, fluxes, coated electrodes, welded joints, thermophysical properties, quality

PJSC «Svet Shakhtyora» is a structural unit of CORUM GROUP Company, producing equipment for mining industry: scraper conveyors and reloaders, cleaning and tunneling combines, mine substations, mine crushers, safety hydraulic clutches, head explosion proof battery lights, and methane analyzers.Products are operated at different mining and climatic conditions in coal, shale and potassium mines. Products are certified in keeping with the requirements of DSTU ISO 90010-2001.Mr. Kovalchuk, your company has been successfully developing during the last three years. It increases the output of mining equipment, where welded structures make up a considerable proportion. Under the conditions, when the market of independent Ukraine has declined, how can you explain intensive development of your company?Yes, indeed, internal market of mining equipment in Ukraine is limited, and the share of sales in the internal market has decreased. The issue of entering foreign markets became more acute, so that individual approach to each order, promptness of its fulfillment and constant communication with users are becoming ever more important. Despite all the difficulties, we increased the range of products manufactured by our company; mastered production of cleaning and tunneling combines, and stable-hole complexes. We also started manufacturing products, earlier untypical for us, namely explosion-proof transformer substations. We are working in the field of high-potential developing plow dredging that will allow us even more expanding the niche occupied by us in mining equipment manufacturing.During 2017, our plant manufactured 17 conveyors of different type, 15 cleaning and tunneling combines, 50 transformer substations, a large volume of spare parts for mining equipment; export accounted for 18 % of product output.Quality, reliability and safety of our products are confirmed by the respective certificates that make them competitive in supplying both the domestic and foreign markets. Reconstruction of production facilities has been performed under your leadership. What has been done to ensure manufacturing competitive products?One of major investments into the equipment of «Svet Shakhtyora» plant in 2014-2017 was purchase of wire EDM machine tool Mitsubishi MV2400S+ and processing center DOOSAN DBC160 (South Korea) with Fanuk 31i-B control system (Japan). The cost of introduction of

No abstract

In the last decade, an urgent and practically significant problem has been producing of high-quality joints of highstrength steels and alloys. For its solution the technologies are required which are distinguished by a high-concentration heating at a minimum energy input, including in continuous flash-butt welding of railway rails. To solve this problem, a mathematical model of the process of metal heating in continuous flash-butt welding was developed. The model allows avoiding labor-consuming and expensive experiments and significantly expanding the range of searching the ways of optimizing at a multifactor control of welding parameters, affecting, in particular, the formation of the temperature field in continuous flash-butt welding of rails. 8. Ref., 12 Figures.

на основании анализа физико-химических свойств вредных примесей обобщены представления о механизме их влияния на образование кристаллизационных трещин в различных металлах, заключающимся, во-первых, в обогащении ими границ кристаллитов (остаточной жидкости) на последних стадиях затвердевания, во-вторых, в проявлении эффекта адсорбционного понижения прочности и пластичности. Установлено различие характера кристаллизации однофазных и двухфазных (с эвтектикой) сплавов в обогащении границ кристаллитов вредными примесями. показано, что наибольшее влияние на образование трещин оказывают удельная поверхностная энергия на границе твердый металл-расплав и границ зерен. Установлено, что на повышенную склонность к образованию кристаллизационных трещин могут влиять и поверхностно-активные легирующие элементы, характеризующиеся теми же физико-химическими свойствами, что и вредные примеси. Формула докритического роста трещины, предложенная е. Э. гликманом и др. может служить критерием оценки влияния поверхностно-активных элементов на образование кристаллизационных трещин. Библиогр. 36, табл. 2, рис. 9.