PSI - Issue 20

Sleptsov O.I. et al. / Procedia Structural Integrity 20 (2019) 143–147 Sleptsov O.I. et al. / Structural Integrity Procedia 00 (2019) 000–000

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Fig.1. Grain boundary microcrack, originated from the inclusion of carbide in the structure of the heat-affected zone of the field joint of steel 12X18H12T after deformation of 15%. x3000 4. Conclusions It was found in the course of the research, that the most susceptible to corrosion destruction are the heat-affected zones of field joints of austenitic steels, which are made with partial or complete non-compliance with the requirements for heat treatment of the heat-affected zone of the field weld, which restores its structure. It is demonstrated that the rejection of such heat treatment leads to the appearance and growth of carbide particles in the structure of the heat-affected zone, which reduces almost two times, from 270 to 150 MPa, the level of stresses that lead to the occurrence of corrosion cracking in the heat-affected zones of the welded joints. Acknowledgements This research has been supported by Ministry of Science and Education of Russian Federation (Project III.28.1). References Ermakov, B.S., Malikov, S.O., Povarov, D.V. and Solntsev, Yu. P., 2006. The role of residual deformations in reducing the performance of pipelines operating at low temperatures. 1. Analysis of the performance of the pipeline metal under the conditions of occurrence of local plastic deformation zones. Izvestia SPbGUNiPT 1, 44-47. Ermakov, B.S. and Solntsev, Yu.P., 2000. Intergranular corrosion - the main factor of accelerated destruction of equipment from austenitic steels. Baltic Metals 2, 18-21. Ermakov, B.S., Vologzhanina, S.A. and Yarygin, G.E., 2004. Corrosion resistance of space industry equipment. Non-destructive testing of ground-based space infrastructure facilities. Conf. Proceedings of SPb Mozhaisky Military Space Academy, 180-184. Evans, Yu. R., 1962. Corrosion and Oxidation of Metals. Mashgiz, Moscow, pp. 855. Kuzyumov, A.N., Krikun, V.P. and Nihaenko, Yu.Ya., 1999. Some features of the corrosion cracking of equipment in sulfate media. Protection of Metals 35(3), 21-23. Ermakov, B.S., Kozachenko, A.V., 2001. The method of non-destructive testing of cryogenic vessels and pipelines. Materials science, plastic and heat treatment of metals, Saint Petersburg: Politechnika, 31-32.