Features of the Metal Structure Formation in Cryogenic Equipment during Long-Term Operation at 4.2 K

Abstract:

This study discusses the role of thermal processes, including repair welding, and maintenance heat-up of cryogenic equipment, in the alteration of the properties of base metal and formation of thermal impact zones during repair and installation of joints from chromium-nickel steels with different nickel content. The tests have confirmed the primary role of nickel in the change of the properties of base metal and welded joints of low-temperature structures during operation and maintenance heat-up. It was shown that maintenance, repair and welding heat-up can lead to structure alteration and material embrittlement, which occurs in all steels, regardless of nickel content. The research has identified the areas that are potentially dangerous from the perspective of the brittle defect evolution in cryogenic equipment operating under complex thermal cycles during operation or maintenance heat-ups.

• Periodical: Key Engineering Materials (Volume 743)
• Pages: 273-278
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.743.273
• Online since: July 2017
• Authors: Boris S. Ermakov, Sergey Ermakov, Alyona Salokeeva*
• Keywords: Austenitic Steel, Complex Thermal Cycle, Cryogenic Equipment, Low-Temperature Structure Alteration, Maintenance Heat-Up, Thermal Impact Zone, Welding

References

[1] Solntsev Yu.P., Ermakov B.S. Endurance of materials of low-temperature structures (in Russian). Saint Petersburg, KHIMIZDAT, 2006. - 512 p.

[2] Solnstev Yu.P., Ermakov B.S., Sleptsov O. I. Materials for low and cryogenic temperatures (in Russian). Reference guide. – Saint Petersburg, KHIMIZDAT, 2008, 768 p.

[3] Startsev V. I., Ilyichev V. Ya., Pustovalov V. V. Plasticity and strength of metals and alloys at low temperatures (in Russian). – Moscow, Metallurgiya, 1975. – 328 p.

[4] Vigli D. A. Mechanical properties of materials under low temperatures (in Russian). – Moscow: Mir, 1974. – 373 p.

[5] Korolev N.V., Kolchin G.G., Ermakov B.S. Application of emission spectral microanalysis to increase reliability of structural materials (in Russian). Leningrad.: LDNTP, 1987. – 29 p.

[6] Khoroshailov V.G., Ermakov B.S. Non-magnetic cryogenic steels (in Russian). – Leningrad.: LDNTP, 1985. – 19 p.

[7] Petrov G.L., Tumarev A.S. Theory of welding processes (in Russian). - Moscow, Higher school, 1967, 508 p.

[8] Shorshorov M. Kh., Chernyshova T.A., Krasovskiy A.I. Testing metals for weldability (in Russian). Moscow, Metallurgiya, 1972, 240 p.

[9] Ermakov B.S., Malikov S.O., Vasilyev A.V. The role of residual deformations in reduction of operability of pipelines operating under low temperatures Part 7. Effect of intercrystallite corrosion on operability of welding joints under long-term exploitation (in Russian). Bulletin of St. Petersburg State University of Refrigeration and Food Processing Technologies, No. 4, 2007, pp.16-20.