OBRABOTKAMETALLOV Vol. 28 No. 2 2026 68 TECHNOLOGY Evaluation of the penetrating ability of oxide fl uxes in welding carbon and low-alloy steels using novel A-TIG methods Antonina Karlina 1, 2, a, *, Vitaliy Gladkikh 1, b, Georgiy Kurdyumov 2, c, Roman Kononenko 3, d, Viktor Kondratiev 2, 4, e 1 National Research Moscow State University of Civil Engineering, 26 Yaroslavskoe Shosse, Moscow, 129337, Russian Federation 2 Cherepovets State University, 5 Lunacharsky pr., Cherepovets, 162600, Russian Federation 3 Irkutsk National Research Technical University, 83 Lermontova str., Irkutsk, 664074, Russian Federation 4 A.P. Vinogradov Institute of Geochemistry SB RAS, 1A Favorskiy St., Irkutsk, 664033, Russian Federation a https://orcid.org/0000-0003-3287-3298, karlinat@mail.com; b https://orcid.org/0000-0003-1953-1584, gladkich_87@mail.ru; c https://orcid.org/0009-0000-8373-1412, gekurdiumov@chsu.ru; d https://orcid.org/0009-0001-5900-065X, istu_politeh@mail.ru; e https://orcid.org/0000-0002-7437-2291, imz@mail.ru Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2026 vol. 28 no. 2 pp. 49–71 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2026-28.2-49-71 ART I CLE I NFO Article history: Received: 18 January 2026 Revised: 14 March 2026 Accepted: 21 March 2026 Available online: 15 June 2026 Keywords: Welding Activating fl uxes Penetration depth Coating thickness ABSTRACT Introduction. The purpose of this study is to evaluate the technological potential of using oxide activating fl uxes in the novel FB-TIG and FZ-TIG methods to improve penetration effi ciency and weld quality in carbon and low-alloy steels. This paper attempts to analyze and review the published literature concerning various hypotheses that explain the high penetration achieved using activating fl uxes. Materials and Methods. Low-alloy steel samples with thicknesses ranging from 3 to 10 mm were used in this study. Fine fl ux powders were pre-dispersed in acetone. The fl ux was carefully applied with a brush to the upper surface of the plate over half of its length. The other half of the plate was left without fl ux to perform conventional TIG welding for comparison. Bead-on-plate welds were made without the addition of any fi ller material. Several parallel weld passes were deposited with suffi cient spacing to avoid thermal interference. The arc current was varied in the range of 80–250 A, while the welding speed was kept constant at 100 mm/min. The welding voltage was set to 15–16 V. Heat input was calculated using the standard expression, assuming a heat transfer effi ciency of 0.8. High-purity, industrial-grade argon was used as the shielding gas at a fl ow rate of 20 L/min. A standard optical microscope was used for metallographic examination, and a camera was used to record the welding process. Results and Discussion. The studies have shown that penetration depth primarily depends on such welding parameters as arc length (mm), welding current (A), and travel speed (mm/s). The depth-to-width (D/W) ratio is high for the FB-TIG method; moreover, surface appearance and slag detachability are improved. The infl uence of the acidic or alkaline nature of the fl ux on weld geometry and surface appearance is analyzed. Acid fl uxes provide a smoother weld surface than alkaline oxide fl uxes. Welding with activated FB-TIG and FZ-TIG using SiO₂ fl ux increases the penetration depth and the depth-to-width ratio by factors of 1.5–1.7, respectively, compared to conventional A-TIG welding. For citation: Karlina A.I., Gladkikh V., Kurdyumov G., Kononenko R.V., Kondratiev V.V. Evaluation of the penetrating ability of oxide fl uxes in welding carbon and low-alloy steels using novel A-TIG methods. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2026, vol. 28, no. 2, pp. 49–71. DOI: 10.17212/1994-6309-2026-28.2-49-71. (In Russian). ______ * Corresponding author Karlina Antonina I., Ph.D. (Engineering), Research Associate National Research Moscow State Construction University, 26 Yaroslavskoe shosse, 129337, Moscow, Russian Federation Tel: +7 950 120-19-50, e-mail: karlinat@mail.ru References 1. Zhang Y.M., Jiang M., Lu W. Double electrodes improve GMAW heat input control. Welding Journal, 2004, vol. 83 (11), pp. 39–41. 2. Xiang R., Huang J., Yu X., Zhao H., Fan D. A review of double-electrode GMAW: Approaches, developments and variants. Journal of Manufacturing Processes, 2025, vol. 133, pp. 1160–1182. DOI: 10.1016/j.jmapro. 2024.12.017.
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