TPWJ, 2014, #6-7, 163-171 pages
EFFECT OF CHARGE GRAIN COMPOSITION ON RHEOLOGICAL CHARACTERISTICS AND STRUCTURE OF PRESSURE FLOW OF COMPOUNDS FOR LOW-HYDROGEN ELECTRODES
Journal The Paton Welding Journal
Publisher International Association «Welding»
ISSN 0957-798X (print)
Issue № 6-7, 2014 (June-July)
E.O. Paton Electric Welding Institute, NASU. 11 Bozhenko Str., 03680, Kiev, Ukraine. E-mail: email@example.com
It is determined in course of investigation of compound of low-hydrogen electrodes UONI-13/55, carried out with the help of capillary viscosimeter, that their rheological indices and structure under flow pressure condition significantly depend on grain composition of coating materials. Charge should contain 50% of fine fraction from point of view of minimizing of energy consumption, necessary for extrusion application of compounds on rods. Deviation of its portion in one or another side from indicated optimum significantly rises energy consumption on electrode extrusion. The compounds with fine- or coarse-grain filler are not similar to each other on structure. It confirms nature of change of level of compound dissipative heating, value of natural convergence angle in entrance zone (to capillary) as well as shape of deformation (extrusion) curves at increase of flow velocity. Profile of flow of compounds with coarse-grain filler expands at rise of pressure jet rate. It remains virtually of the same narrow shape as at creep flow velocities for flow of compounds with fine-grain filler. The results of analysis of form of extrusion curves P = f(t) indicate that pressure flow of compound with coarse-grain filler is realized on viscosity mechanism. The compounds with excessive content of fine-grain filler are more structured, since liquid glass binder in these cases in addition to filling of intergrain voids should cover significantly more developed grain surface. Rise is observed in their molecular interaction and strength of structure formed by them, which is fractured in deformation and accompanied by specific phenomena of unsteady flow. 8 Ref., 2 Tables, 8 Figures.
low-hydrogen welding electrodes, coating thickness difference, rheology of compounds, viscosity and elasticity indices of compounds
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