The Paton Welding Journal, 2019, №06



2019 №06 (12)

DOI of Article 10.15407/tpwj2019.06.13

2019 №06 (01)

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The Paton Welding Journal, 2019, #6, 65-70 pages

Journal The Paton Welding Journal
Publisher International Association «Welding»
ISSN 0957-798X (print)
Issue #6, 2019 (June)
Pages 65-70

Scandium effect on the properties and structure of alloys of Al–Zn–Mg–Cu system and their welded joints

V.E. Fedorchuk¹, A.G. Poklyatsky², Yu.V. Falchenko¹ and G.P. Kislaya²

¹E.O. Paton Electric Welding Institute of the NAS of Ukraine 11 Kazimir Malevich Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua
²NTUU «Igor Sikorsky KPI» 37 Pobedy Ave., 03056, Kyiv, Ukraine

The effect of scandium additives on structure and mechanical properties of cast metal, sheet semi-finished products and butt joints made by nonconsumable electrode argon-arc welding of aluminum alloys of Al–Zn–Mg–Cu alloying system was studied. It is shown that scandium-containing alloys, both in the cast metal, and in their sheet semi-finished products, all the structural components have smaller dimensions, than in the alloys without scandium, that ensures the ultimate strength of the sheets on the level of 640–700 MPa, depending on content of main alloying elements in them. It is established that in nonconsumable argon-arc welding of 3 mm sheets from scandium-containing alloys the total length of the softening zone is reduced by 20 % at simultaneous increase of weld metal hardness that provides higher mechanical properties of such joints. Complex addition of scandium to base material and filler wire simultaneously that ensures its content in the weld metal on the level of 0.30–0.35 % allows significantly increasing the resistance of welded joints of Al–Zn–Mg–Cu system to hot solidification cracking. 16 Ref., 3 Tables, 4 Figures.
Keywords: aluminum alloys, Al–Zn–Mg–Cu alloying system, scandium, microstructure, mechanical properties, hot cracks


Received: 17.01.19
Published: 20.06.19

References

1. Bondarev, B.I., Elagin, V.I. (1992) New aluminium alloys, doped with scandium. Tekhnologiya Lyogkikh Splavov, 5, 22-28 [in Russian].
2. Davydov, V.G., Elagin, V.I., Zakharov, V.V., Rostova, T.D. (1996) On alloying of aluminium alloys with scandium and zirconium additives. Metallovedenie i Termich. Obrab. Metallov, 8, 25-30 [in Russian]. https://doi.org/10.1007/BF01395323
3. Ishchenko, A.Ya. (2003) Aluminium high-strength alloys for welded structures. Progresyvni Materialy i Tekhnologii. Kiev, Akademperiodika, Vol. 1, 50-82 [in Russian].
4. Milman, Yu.V. (2003) Effect of scandium on structure, mechanical properties and corrosion resistance of aluminium alloys. Progresyvni Materialy i Tekhnologii. Kiev, Akademperiodika, Vol. 1, 335-360 [in Russian].
5. Elagin, V.I., Shvechkov, E.I., Filatov, Yu.L., Zakharov, V.V. (2005) Corrosion resistance of sheets of Al-Mg-Sc alloys. Tekhnologiya Lyogkikh Splavov, 1-4, 40-44 [in Russian].
6. Ishchenko, A.Ya., Lozovskaya, A.V., Poklyatsky, A.G. et al. (1999) Structure and properties of joints produced in welding of AMg6 alloy using the filler wires with scandium. Avtomatich. Svarka, 4, 19-25 [in Russian].
7. Ryazantsev, V.I., Filatov, Yu.A. (2003) Technological aspects of arc welding of aluminium alloys with scandium. Aviats. Promyshlennost, 1, 13-17 [in Russian]. https://doi.org/10.1533/wint.2003.3212
8. Turkina, N.I., Semenova, B.V. (1992) Structure and properties of Al-Mg--Li system alloys doped with scandium. Tekhnologiya Lyogkikh Splavov, 1, 57-59 [in Russian].
9. Ishchenko, A.Ya., Lozovskaya, A.V., Poklyatsky, A.G. et al. (2002) Increase in strength of welds in arc welding of alloy 1420 using the Sc-containing fillers. The Paton Welding J., 1, 10-14.
10. Bratukhin, A.G., Tretyak, N.G., Sklabinskaya, I.E. (1993) Structure and mechanical properties of welded joints of aluminium-lithium alloys in welding by experimental additives with scandium. Avtomatich. Svarka, 12, 11-15 [in Russian].
11. Poklyatsky, A.G., Lozovskaya, A.V., Grinyuk, A.A. et al. (2006) Improvement of weld strength in arc welding of Al-Cu alloys with application of Sc-containing fillers. The Paton Welding J., 2, 26-29.
12. Zakharov, V.V., Rostova, T.D. (1995) Alloying with scandium of Cu-containing alloys. Metallovedenie i Termich. Obrab. Metallov, 2, 23-27 [in Russian].
13. Elagin, V.I., Zakharov, V.V., Rostova, T.D., Filatov, Yu.A. (1989) Some materials science principles of alloying, technology of manufacturing and heat treatment of Sc-containing aluminium alloys. Tekhnologiya Lyogkikh Splavov, 9, 27-34 [in Russian].
14. Fedorchuk, V.E. (2015) Special features of the formation of the microstructure and chemical heterogeneity in welded joints in alloys of the Al-Zn-Mg-Cu system alloyed with scandium. Welding International, 29(8), 619-623. doi:10.1080/09507116.2014.960695. https://doi.org/10.1080/09507116.2014.960695
15. Fridlyander, I.N., Senatorova, O.G., Novikov, I.N. et al. (1993) Superplasticity of high-strength Sc-doped alloys of Al-Zn-Mg-Cu system. Tekhnologiya Lyogkikh Splavov, 7-8, 43-47 [in Russian].
16. (1967) GOST 6996-66: Welded joints. Methods of mechanical tests. Moscow, Standarty [in Russian].

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