Influence of the heat transfer coefficient on the level of residual stress after heat treatment of the VVER-1000 reactor baffle
DOI:
https://doi.org/10.20535/2521-1943.2021.5.2.245074Keywords:
VVER-1000 reactor, internals, baffle, welding, heat treatment, austenitization, residual stresses, mathematical modelingAbstract
Background. Improvement of the methodology for the computational analysis of residual stresses in the structural elements of the reactor is an integral part of the work when extending the service life of NPP power units.
Objective. Determine the value of residual technological stress arising in the baffle of a VVER-1000 reactor during welding and postweld heat treatment according to the austenitizing mode. To evaluate the effect of considering the dependence of the heat transfer coefficient on the temperature of the baffle surface at cooling in air during heat treatment.
Methods. Numerical modeling of the stress-strain state of the baffle during welding and postweld heat treatment was carried out using the finite element method.
Results. It was determined that in the process of heat treatment according to the austenitizing mode, the residual welding stress in the baffle are almost completely relaxed. Due to the high temperature gradient during rapid cooling in air after heating in the process of austenitization, new rather high residual stresses are formed in the zones of the baffle with the greatest metal thickness.
Conclusions. Based on the results of the investigation, a high level of residual technological stress was determined, which should be considered when calculating the justification for extending the service life of the VVER-1000 reactor baffle.
References
- A. Yu. Chirkov and V. V. Kharchenko, “Special features of computational assessment of the change in shape of WWER-1000 reactor core baffle in view of irradiation-induced swelling”, Strength of Materials, vol. 52, no. 3, pp. 339–352, 2020. DOI: https://doi.org/10.1007/s11223-020-00184-9.
- A. S. Kalchenko, V. V. Bryk, V. N. Voevodin and N. P. Lazarev, "Prediction of radiation swelling of VVER-1000 reactors baffle ring for service life up to 30-60 years", Nuclear Physics and Atomic Energy, vol. 12, no. 1, pp. 69–77, 2011.
- O. V. Makhnenko, I. V. Mirzov and V. B. Porokhonko, “Modelling of residual stresses, radiation swelling and stressed state of in-service WWER-1000 reactor baffle”, Automatic Welding, no. 4, pp. 35-41, 2016. DOI: https://doi.org/10.15407/as2016.04.03.
- SOU NAEK 159:2020. Zabezpechennya tekhnichnoyi bezpeky. Zvaryuvannya ta naplavlennya ustatkuvannya i truboprovodiv atomnykh elektrychnykh stantsiy z reaktoramy VVER. Tekhnichni vymohy.
- V. I. Makhnenko, Raschetnyye metody issledovaniya kinetiki svarochnykh napryazheniy i deformatsiy. Kyiv: Naukova dumka, 1976, 320 p.
- Yu. N. Rabotnov, Polzuchest' elementov konstruktsiy. Moscow: Nauka, 1966, 752 p.
- STP 26.260.484-2004. Termicheskaya obrabotka korrozionno-stoykikh staley i splavov na zhelezonikelevoy osnove v khimicheskom mashinostroyenii.
- B. Z. Margolin, A. G. Gulenko, I. P. Kursevich and A. A. Buchatskii, “Modeling for fracture in materials under long-term static creep loading and neutron irradiation. Part 2. Prediction of creep rupture strength for austenitic materials”, Strength of Materials, vol. 38, no. 5, pp. 449–457, 2006. DOI: https://doi.org/10.1007/s11223-006-0064-z.
- A. L. Nemchinskiy, Teplovyye raschety termicheskoy obrabotki. Leningrad: Sudpromgiz, 1953, 106 p.
- M. V. Maisuradze, M. A. Ryzhkov et al., “Metodika opredeleniya okhlazhdayushchey sposobnosti zakalochnykh sred”, in Materialy IV Mezhdunarodnoy nauchno-prakticheskoy konferentsii "Innovatsii v materialovedenii i metallurgii", Ekaterinburg, Russia, 2015, pp. 114–117.
- O. V. Makhnenko, S. M. Kandala, N. R. Basistyuk and M. V. Cherkashin, “Mathematical modeling of residual stresses in WWER-1000 elements after heat treatment”, Automatic Welding, no. 3, pp. 10-16, 2021. DOI: https://doi.org/10.37434/as2021.03.02.

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Copyright (c) 2021 Олег Махненко, Степан Кандала, Назар Басистюк

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