The Paton Welding Journal, 2021, №05



2021 №05 (05)

DOI of Article 10.37434/tpwj2021.05.06

2021 №05 (07)

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The Paton Welding Journal, 2021, #5, 35-40 pages

Effect of thermal cycles in electron beam welding of aluminium 1570 alloy on mechanical properties of welded joints

V.M. Nesterenkov, V.V. Skryabinskyi and M.O. Rusynyk

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
The effect of welding speed on strength of joints and size of the heat-affected-zone in electron beam welding of 1570 alloy was investigated. Thermal cycles in the tail part of the welding pool and spots in the metal surface in the near-weld zone were determined. According to the thermal cycles of the welding pool, the rate of hardening of the weld metal was calculated and its effect on mechanical properties of the joints before and after artificial aging was investigated. Decrease in the welding speed and, consequently, increase in the lifetime of the liquid phase leads to the growth of hardness of the weld metal after aging, which is probably associated with a more complete dissolution of primary scandium intermetallics and its transition to a supersaturated solid solution during cooling. Measuring the hardness of metal in the cross-section of the joints, according to the thermal cycles of the corresponding points, it was determined that the temperature of the beginning of the loss of strength of the metal in electron beam welding of 1570 alloy is in the range of 450‒560 °С. It was found that artificial aging provides full strength welded joints with stamped semi-finished products, and explosion treatment is ineffective. It is possible to increase the strength of joints to the level of strength of hardened plates by 20 % applying plastic deformation and a subsequent artificial aging. 7 Ref., 3 Tables, 8 Figures.
Keywords: electron beam welding, aluminium alloy, welded joints, thermal cycles, mechanical properties, artificial aging

Received 14.04.2021

References

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