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2020 №11 (06) DOI of Article
10.37434/tpwj2020.11.07
2020 №11 (08)


The Paton Welding Journal, 2020, #11, 32-35 pages

Development of the technology of semi-automatic arc welding for the conditions of overhaul and reconstruction of the linear part of the main gas pipelines of Ukraine

S.Yu. Maksymov, A.A. Gavrilyuk and D.M. Krazhanovskyi


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
More than 37 thou km of gas pipelines were laid through the territory of Ukraine. Their safe operation is based on proper technical maintenance and timely repair or reconstruction. At present manual arc welding is the main welding method used during performance of repair. Its low productivity necessitates shortening the duration of welding operations with simultaneous improvement of their quality. The objective of the work was development of the main principles and technology of semi-automatic arc welding of position circumferential butt joints of pipes of up to 1420 mm diameter inclusive that will enable shortening the time of welding operations performance, with the corresponding acceleration of laying of the restored sections of the main gas pipelines and simultaneous improvement of welded joint quality. Welding was performed by gas-shielded flux-cored wire ОК Tubrod 15.19 of 1.2 mm diameter in Ar + СО2 atmosphere and self-shielded flux-cored wire Coreshield 8 of 1.6 mm diameter. Analysis of the obtained results shows that the site of sample destruction is located in the base metal in all the cases. Such results indicate that the welded joint strength is higher than that of the base metal for these combinations of welding consumables and shielding gas. With the proper welding practices and strict adherence to the welding mode, butt joints of pipe steels comply with the normative documents, and flux-cored wire ОК Tubrod 15.19 can be recommended for welding pipe steels of strength class K-60, while self-shielded flux-cored wire Coreshield 8 can be used for welding pipe steels of strength class К-52. 15 Ref., 6 Tables.
Keywords: main gas pipeline, semi-automatic arc welding, circumferential butt joint, flux-cored wire

Received 28.09.2020

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