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2021 №04 (02) DOI of Article
10.37434/tpwj2021.04.03
2021 №04 (04)


The Paton Welding Journal, 2021, #4, 14-19 pages

Influence of liquid glass characteristics on quality of coating formation of welding electrodes

A.E. Marchenko1, I.O. Glot2, M.V. Skoryna1


1E.O. Paton Electric Welding Institute of the NAS of Ukraine. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua
2Institute of Continuous Media Mechanics of the Ural Branch of the RAS, 1, Academician Korolyov Str., 614018, Perm, Russia

Abstract
The viscosity of 6 % dispersions of Na-CMC in liquid Na- and K-glasses depending on temperature, as well as viscosity of pure liquid Na, K- and NaK-glasses depending on excess pressure and temperature was studied. Each of them represents a consistent medium of real electrode coating mixtures. With the use of the obtained results by mathematical methods, the functioning of the model of a joint effect of excess pressure and dissipative heating on viscosity, velocity profile and stability of pressure flow of electrode coating mixtures in the step channel under the conditions of coating formation by extrusion deposition on steel bars was verified. Although two competing sources of change in shear viscosity of the coating mass (temperature and pressure) are available, the calculations did not reveal situations with unstable (pulsating) flow modes through a suddenly narrowing channel, which could cause instability of the coating mixture flow and, therefore, electrode coatings with a thickness variation. At least, they were not revealed in the studied range of capillary sizes L/Rk < 10 and pressures, at which the electrodes are actually pressed. 10 Ref., 1 Table, 8 Figures.
Keywords: arc welding, coated electrodes, production technology, coating thickness variation, rheology, viscoelasticity of coatings

Received 22.03.2021

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