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2020 №12 (05) DOI of Article
10.37434/tpwj2020.12.06 		2020 №12 (07)

The Paton Welding Journal 2020 №12


The Paton Welding Journal, 2020, #12, 40-47 pages

Corrosion and mechanical resistance of welded joints of aluminium B1341T alloy, produced by argon arc welding using free and constricted arc

L.I. Nyrkova, T.M. Labur, S.O. Osadchuk and M.R. Yavorska


E.O. Paton Electric Welding Institute of the NAS of Ukraine 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua

Abstract
In the work the results of studies of corrosion and mechanical resistance of welded joints of B1341T alloy with a thickness of 1.2 mm, depending on the technology of manual argon arc welding using free and constricted arc are presented. The strength coefficient of welded joints is 0.79 and 0.8, respectively. Potentiometric measurements established an electrochemical heterogeneity between the base metal and the welded joints produced using free and constricted arc, which is equal to 100 mV and 86 mV, respectively. More positive potential is inherent to the region of a weld with a smaller area, which is safe to operation. Accelerated corrosion tests determined that the shape of the arc column during manual welding does not affect the resistance of welded joints to exfoliating corrosion and a corrosion-mechanical resistance under the conditions of a constant deformation. The level of resistance of the metal to exfoliating corrosion of the joints produced by both types of arc welding technology, was estimated by the point 2–3. The fracture time of the specimens welded by free arc welding, decreased on average to 20 days as compared to the base metal (73 days). The similar results were obtained for the joints welded by a constricted arc. At the same time, it was revealed that the use of constricted arc for welding, causes a decrease in the resistance of the joints to intercrystalline corrosion. The maximum fracture depth of the boundaries’ grains is 0.350 mm for the joints produced by a free arc and 0.460 mm for the joints made by a constricted arc. 15 Ref., 3 Tables, 11 Figures.
Keywords: aluminium alloy, free and constricted arc welding, welded joint, mechanical properties, structure, intercrystalline corrosion, exfoliating corrosion, corrosion under constant deformation, potentiometry, accelerated corrosion tests

Received 12.11.2020

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