The Paton Welding Journal, 2023, #8, 17-28 pages
Influence of the speed of plasma-arc welding at a variable polarity asymmetrical current on the formation of joints of high-strength aluminium alloys
V.M. Korzhyk1, A.A. Grynyuk1, V.Yu. Khaskin1, E.V. Illyashenko1, S.I. Peleshenko2, A.O. Aloshyn2, I.O. Skachkov3, O.V. Dolyanivska3
1E.O. Paton Electric Welding Institute of the NASU..
11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: vnkorzhyk@gmail.com
2LLC “Foreign Economic Representation of the E.O. Paton Chinese-Ukrainian Institute of Welding, 11 Kazymyr Malevych Str.,
03150, Kyiv, Ukraine
3National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 37 Peremohy Prosp., 03056, Kyiv, Ukraine
Abstract
The effect of change in the speed of movement of the heating source in plasma-arc welding of aluminium alloys of 2.0 mm
thick of three Al–Mg–Mn (AMg5M, AMg6), Al–Cu–Mn (1201) and Al–Cu–Li (1460) alloying systems on the microstructure
and hardness of the weld metal and near-weld zone, on the formation of inner pores and mechanical properties of welded joints
was considered. Changes in the distribution of temperature fields and indices of the stress-strain state of welded specimens were
analyzed. It was found that for each type of alloys there is a certain “peak” welding speed, with exceeding of which there is no
significant reduction in residual deformations and stresses, as well as a decrease in the width of the base metal heating zone.
Instead, mechanical properties of welded joints are deteriorated because of an increase in the number of pores in the weld metal
and the formation of inadmissible undercuts in the upper part of the weld in the area of transition from the weld to the base metal.
On the example of Al–Mg–Mn alloy it is shown that such regularities are also typical not only for the thickness of 2.0 mm, but
also observed during welding of specimens with the range of thicknesses of 4–8 mm. This allows using these results to predict
indices of strength of the welded joint and weld metal for these thicknesses when the speed of plasma-arc welding at a variable
polarity asymmetrical current is increased higher than the “peak” value. 15 Ref., 2 Tabl., 23 Fig.
Keywords: plasma-arc welding, variable polarity pulses, aluminium alloys, weld structure, pores, joint formation, strength,
temperature distribution, stress-strain state
Received: 19.06.2023
Accepted: 07.08.2023
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Suggested Citation
V.M. Korzhyk, A.A. Grynyuk, V.Yu. Khaskin, E.V. Illyashenko, S.I. Peleshenko, A.O. Aloshyn, I.O. Skachkov, O.V. Dolyanivska (2023) Influence of the speed of plasma-arc welding at a variable polarity asymmetrical current on the formation of joints of high-strength aluminium alloys.
The Paton Welding J., 08, 17-28.