Automatic Welding, 2023, №04



2023 №04 (04)

DOI of Article 10.37434/as2023.04.05

2023 №04 (06)

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Avtomaticheskaya Svarka (Automatic Welding), #4, 2023, pp. 28-34

Technology of MIG welding of chromium steel of martensitic grade СА-6NM

A.R. Gavryk¹, A.K. Tsaryuk¹, I.G. Osypenko¹, O.V. Lynnyk², O.V. Vavilov², O.G. Kantor²

¹E.O. Paton Electric Welding Institute of the NAS of Ukraine. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua
²JSC “Ukrainian Energy Machines”. 199 Moskovsky Ave., 61037, Kharkiv, Ukraine. E-mail: office@ukrenergymashines.com

The weldability of the martensitic steel CA-6NM was investigated and the fundamental technology of its mechanized welding in a mixture of shielding gases was developed according to the requirements for the manufacture of critical parts and assemblies of the hydro-turbine equipment, as well as rewelding of casting defects. According to the strength level of the steel, the welding wire Thermanit 13/04 Si of a solid cross-section with a diameter of 1.2 mm and one of the variants of the protective mixture Mix 1 (82 % Ar + 18 % CO2) were selected and comprehensively investigated according to EN 12072/G 134 (Germany). It was established that in order to prevent the formation of cold cracks in welded joints, it is necessary to perform welding of this steel with a preliminary and accompanying heating up to 150…200 °C and a mandatory postweld tempering at a temperature of 600 °C. The developed technology provides a significant improvement in mechanical properties of welded joints of weld metal (by 30…35 % higher than specified by the requirements to the level of the base metal of chromium steel CA-6NM). Certification of the technology was carried out and recommendations for its production use at the JSC “Ukrainian Energy Machines” were worked out. 17 Ref., 5 Tabl., 8 Fig.
Keywords: mechanized welding, martensitic steel, mixture of shielding gases, diffusion hydrogen, cold cracks, mechanical properties, structure


Received: 11.04.2023

References

1. Instruction GTI-407-2018 (2018) Hydraulic turbines. Technical requirements on quality of producing the cast welded wheels of radial-flow turbines. Kharkov, Turboatom [in Russian].
2. Volichenko, N.P., Tsebrenko, E.K. (2009) Welding in turbine construction of Ukraine. Svarshchik, 2, 66 [in Russian].
3. Paton, B.E. (2013) Research and developments of the E.O.Paton Electric Welding Institute for nowadays power engineering. The Paton Welding J., 10-11, 14-22. https://doi.org/10.15407/tpwj2014.06.03
4. Tsaryuk, A.K., Levchenko, E.V., Grishin, MM. et al. (2020) Welding in power engineering industry of Ukraine. The Paton Welding J., 3, 19-24. https://doi.org/10.37434/tpwj2020.03.03
5. Rimsky, S.T. (2006) Guide on mechanized shielded-gas welding. Kyiv, Ekotekhnologiya [in Russian].
6. Kononenko, V.Ya. (2007) Shielded-gas consumable and nonconsumable electrode welding. Kyiv, Niko-Print [in Russian].
7. Kozlov, R.A. (1986) Welding of heat-resistant steels. Leningrad, Mashinostroenie [in Russian].
8. Potapov, N.M. (1976) Principles of flux selection in welding of steels. Moscow, Mashinostroenie [in Russian].
9. Sawhill, J.M., Dix, A.W., Savage, W.F. (1974) Modified implant test for studying delayed cracking. Welding J., 12, 554- 560.
10. Kasatkin,B.S., Musiyachenko, V.F. (1970) High-strength low-alloyed steels for welded structures. Kyiv, Tekhnika [in Russian].
11. Anokhov, A.E., Zemskova, M.S. et al. (1974) Verification of serviceability of butt joints of pipelines made by semiautomatic CO2-welding. The Paton Welding J., 8, 43-46.
12. Tsaryuk, A.K., Ivanenko, V.D., Kozlovets, O.N. (1995) Influence of welding material purity on properties of weld metal of heat-resistant steel 15Kh1M1F joints. Ibid., 5, 45-46 [in Russian].
13. Bilmes, P.D., Llorente, C., Perez. Ipina J. (2000) Toughness and microstructure of 13Cr4NiMo high-strength steel welds. J. Mater. Eng. and Performance, 9(6), 609-615. https://doi.org/10.1361/105994900770345458
14. Casas, W.J.P., Henke, S.L., Novicki, N. (2009) Fracture toughness of CA6NM alloy, quenched and tempered, and of its welded joint without PWHT. Welding International, 23(3), 166-172. https://doi.org/10.1080/09507110802543344
15. Rymkevich, A.I. (1980) Welding of low-alloyed 13% chromium steel for producing of uniform and dissimilar joints. Svarochn. Proizvodstvo, 9, 1-12 [in Russian].
16. Rymkevich, A.I. (1986) Selection of electrodes for welding of high-strength corrosion-resistant steels. Avtomatich. Svarka, 6, 57-60 [in Russian].
17. Bilmes, P.D. et al. (2009) Microstructure, heat treatment and pitting corrosion of 13CrNiMo plate and weld metals. Corrosion Sci., 51(4), 876-81. https://doi.org/10.1016/j.corsci.2009.01.018

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