Print

2021 №04 (02) DOI of Article
10.37434/as2021.04.03
2021 №04 (04)


Avtomaticheskaya Svarka (Automatic Welding), #4, 2021, pp.

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

A.E. Marchenko1, I.O. Glot2, М.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

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 masses. Using the obtained results, by mathematical methods the functioning of the model of the joint effect of overpressure and dissipative heating on viscosity, velocity profile and stability of pressure flow of electrode coatings 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 mass flow, and therefore electrode coatings with a thickness variation. At least, they were revealed in the studied range of capillary L/Rk <10 sizes and pressures, at which the electrodes are actually pressed. 10 Ref., 1 Tabl. , 8 Fig. Keywords: arc welding, coated electrodes, production technology, coating thickness variation, rheology, viscoelasticity of coating masses


Received: 22.03.2021

References

1. Cogswell, F.N. (1972) Converging flow of polymer melts in extrusion dies. Polym. Eng. and Sci., 12(2), 64-73. https://doi.org/10.1002/pen.760120111
2. Kamal, M.R., Nuyn, H. (1980) Capillary viscometry a complete analysis including pressure and viscous heating effect. Ibid., 20(2), 109-119. https://doi.org/10.1002/pen.760200202
3. Marchenko, A.E., Skorina, N.V., Sidlin, Z.A., Kostyuchenko, V.P. (1992) Examination of viscosity of liquid glasses under pressure of electrode crimping. In: Proc. of Sci.-Tech. Seminar dedicated to the 100th Anniversary of the Birth of K.V. Petran on New Welding and Surfacing Materials and their Application in Industry (St.-Petersburg, 19-20 May, 1992). St.-Petersburg, 43-49 [in Russian].
4. Khodakov, G.S. (2003) Rheology of suspensions. Theory of phase flow and its experimental substantiation. Ros. Khim. Zhurnal, XLVII, 2, 33-44 [in Russian].
5. Vinogradov, G.V., Malkin, A.Ya. (1977) Rheology of polymers. Moscow, Khimiya [in Russian].
6. Ayler R.K. (1982) Chemistry of silica. In: 2 Pts, Pt.1. Ed. by V.P. Pryanishnikov. Moscow, Mir [in Russian].
7. Korneev, V.I., Danilov, V.V. (1996) Liquid and soluble glass. St.-Petersburg, Strojizdat [in Russian].
8. Marchenko, A.E., Skorina, N.V., Kiselev, M.O., Trachevsky, V.V. (2017) Nuclear magnetic spectroscopy study of the structure of liquid glasses for welding electrodes. The Paton Welding J., 1, 41-45. https://doi.org/10.15407/tpwj2017.01.07
9. Yankov, V.I., Glot, I.O., Trufanova, N.M., Shakirov, N.V. (2010) Flow of polymers in die holes. Theory, calculation, practice. Moscow, Izhevsk, ICI [in Russian].
10. Marchenko, A.E. (2015) On thermal environment created by viscous heating of electrode paste in the zone of formation of pressure flow. Welding materials - 2015 (Petran lectures). In: Proc. of Int. Sci.-Tech. Conf. (St.-Petersburg, 15-17 October, 2015). St.-Petersburg, 65-68.

Advertising in this issue: