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Nikolay Sergeevich Dunyashin, head of technological machines and equipment department, senior lecturer, candidate of engineering sciences.
Tashkent State Technical University E-mail: [email protected] Leonid Vladimirovich Galperin, SP OOO (joint venture limited liability company) "Po'lat-quvurservis", vice director E-mail: [email protected] Ziyadulla Dosmatovich Ermatov, senior lecturer of technological machines and equipment department Tashkent State Technical University E-mail: [email protected]
ON THE DEVELOPMENT OF A PHYSICAL SIMULATION OF THE CAST METAL WELD CHEMICAL COMPOSITION FORMATION DURING MANUAL ARC WELDING ON THE BASIS OF THE ELECTRODE COATING MIXTURE COMPONENTS CLASSIFICATION
Abstract. The article proposes a physical simulation of the cast metal weld chemical composition formation during manual arc welding with coated electrodes that shows the structure of this process, the interaction and transfer of the electrode coating components, as well as the formation of metal and slag baths.
Keywords: electrode, physical simulation, manual arc welding, electrode coating components classification.
Global sales of welding technologies and equipment at the beginning of 2018 are approximately 52 billion USD and welding materials are 7.2 billion USD. Official data indicates Uzbekistan demand for welding electrodes is 14.5 thousand tons. Their imports exceeded 12 million USD. The main producers of electrodes in the Republic of Uzbekistan are SP OOO (joint venture limited liability company) "Tash-kentsky Trubniy Zavod Imeni V. P. Galperina" (produces 2 thousand tons), AO (company limited) "Uzmetkombinat" (1.2 thousand tons), PO (production association) "Navoiysky Mekhanichesky Zavod" GP (State Enterprise) NGMK (0.5 thousand tons). However, the lack of scientific support in the manufacturing of electrodes and high-quality materials for coating not only reduces the quality of the products, but also leads to a decrease in its share in the domestic and foreign markets. The main reason for this is the scientifically unjustified approach to the development of a mixture for electrode wire coating, which makes purchasing of raw materials and technologies from abroad necessary.
The physical simulation of the cast metal weld chemical composition formation during manual arc welding with coated electrodes is necessary to describe all the processes occurring in the welding zone from the moment the arc starts to the moment welding is completed. To create a physical simulation of the cast metal weld chemical composition forma-
tion during manual arc welding with coated electrodes in the welding zone, the following physical and chemical processes are recognized:
- heating and melting of the base metal of the weld by the heat of the electric arc;
- heating and melting of the electrode rod by passing current and heat of an electric arc and the formation of a metal droplet;
- transfer to the weld pool of the electrode metal;
- mixing of the main and electrode metals in the weld pool;
- chemical reactions occurring as a result of the interaction of the components of the coating in the slag bath;
- crystallization as the heat source of the weld metal is removed [1; 2].
The physical simulation of the cast metal weld chemical composition formation during manual arc welding with coated electrodes is based on the electrode coating components classification [3]:
1) Pure Metals (iron powder, electrolytic copper powder, aluminum powder, molybdenum powder, nickel powder, titanium powder, metallic manganese, metallic tungsten);
2) Ferroalloys (ferroboron, ferrovanadium, ferromom-libden, ferrochrome, ferro-aluminum, ferrotitanium, ferrosili-con, ferromanganese);
ON THE DEVELOPMENT OF A PHYSICAL SIMULATION OF THE CAST METAL WELD CHEMICAL COMPOSITION FORMATION DURING MANUAL..,
3) Mineral Raw Materials (carbonates, titanium-containing materials, aluminosilicates, fluorine-containing raw materials, silicates, quartz materials, iron and manganese ores);
4) Artificially Produced Chemicals (fluorine-containing materials, chlorine-containing materials, carbonates, oxides);
5) Organic Materials (cellulose electrode, carboxymethyl cellulose, starch, dextrin, dextrinol, wood flour).
The physicochemical processes of the cast metal weld chemical composition formation during manual arc welding with coated electrodes can be represented as a diagram as shown in (Fig. 1).
The electrode is a supplier of metal droplets that form the weld metal. Droplets are formed by melting the electrode rod, the metal elements of the coating (Group No. 1. Pure Metals and No. 2 Ferroalloys of the electrode coating components classification) and the metal recovered from slag (Group No. 3. Mineral Raw Materials and No. 2 Artificially Produced Chemicals of the electrode coating components classification). All this metal goes to the weld pool, mixes with the base metal, and after solidification forms a weld.
Figure 1. Physical simulation of the process of the weld metal cast structure formation during manual arc welding
1 - melting of the electrode rod and the formation of a metal droplet; 2 - melting of the metal components of the electrode coating and the formation of a metal droplet (Group No. 1. Pure Metals and No. 2 Ferroalloys of the electrode coating components classification); 3 - melting of the non-metallic components of the electrode coating and the formation of a slag film (Group No. 3. Mineral Raw Materials and No. 2 Artificially Produced Chemicals of the electrode coating components classification); 4 - transfer of elements from the slag shell into the metal droplet and from the metal
droplet and the slag shell; 5 - transfer of droplets of the electrode metal in the weld pool; 6 - transfer of the slag shell of electrode metal droplets into the slag cover of the weld pool; 7 - melting of the base metal and the formation of the weld pool; 8 - solidification of the slag melt; 9 - crystallization of the metal melt.
A mathematical model of the cast metal weld chemical composition formation will be developed on the basis of the physical simulation of the process of the cast metal structure weld formation during manual arc welding.
References:
1. Вотинова Е. Б. Разработка методики расчета состава металла шва при сварке покрытыми электродами или порошковой проволокой / Е. Б. Вотинова, М. П. Шалимов // Сварка и диагностика. 2011.- № 5.- С. 31-35.
2. Вотинова Е. Б. Моделирование процессов взаимодействия металла и шлака при ручной дуговой сварке / Е. Б. Вотинова, М. П. Шалимов // Сварка и диагностика: сборник докладов научно-технической конференции. Екатеринбург. 2012.- С. 33-41.
3. Ermatov Z. D., Dunyashin N. S. Development of electrodes for shielded metal arc welding based on the classification of the coating charge components // European science review, 2018.- No. 11-12.- P. 40-41.
