Automatic Welding, 2025, №01

2025 №01 (04)

DOI of Article 10.37434/as2025.01.05

2025 №01 (06)

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"Avtomatychne Zvaryuvannya" (Automatic Welding), #1, 2024, pp. 30-39

Electron beam welding of gas valve elements from Mo-Ti-Zr alloy

V.I. Zagornikov, V.M. Nesterenkov, K.S. Khripko, O.N. Ignatusha

E.O. Paton Electric Welding Institute of the NAS of Ukraine 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: zagornikov@technobeam.com.ua

The technological techniques of electron beam welding (EBW) are considered, the application of which would allow obtaining the required quality of joints of gas valve parts made of Mo-Ti-Zr (TZM) alloy, which is used in difficult conditions of the nuclear industry. It is known that in order to produce a welded joint with relatively high ductility indices, the oxygen content should not exceed thousandths of a percent. Alloys produced by vacuum-arc and electron beam melting are used for welded structures. They have a much lower tendency to form porosity in welded joints than similar alloys made by powder metallurgy methods. Such alloys can be welded, but these joints cannot always be used under dynamic loads. When choosing the optimal welding technique for gas valve parts, technical requirements for edge preparation, quality of welded joints, availability of appropriate equipment and technological equipment were taken into account. The problems of assembly and subsequent welding of gas valve parts made of Mo-Ti-Zr (TZM) alloy revealed during the investigations caused the need in changing the design of the joints. As a result, a scheme for welding gas valve parts was proposed, which uses flanging of weld butt edges. This led to optimizing the penetration shape. The proposed welding parameters and the geometry of the flange made it possible to reduce the degree of saturation of the weld metal with gases due to the reduction in the penetration depth under the conditions of rapid heat removal and, as a result, to produce sufficiently high-quality welded joints. In addition, with all the variety of technological techniques used during the investigations, the priority of the correctly selected design of the circumferential joint and the accuracy of the welding assembly was proven. 16 Ref., 3 Tabl., 10 Fig.
Keywords: Mo-Ti-Zr (TZM) alloy, electron beam welding (EBW), microstructure, porosity, gas valve, flanging of welded edges


Received: 20.06.2024
Received in revised form: 25.10.2024
Accepted: 10.12.2024

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