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Information × Registration Number 0221U100981, 0119U101748 , R & D reports Title "Extension of the service life of the metal for pipe lines of second circuit for power units of WWER-1000 for near 20 and more years" popup.stage_title Head Mitrofanov Anatoliy S., Кандидат технічних наук Registration Date 11-01-2021 Organization National Science Center "Kharkiv Institute of Physics and Technology" popup.description2 The causes of metal damage of steel 20 pipelines used in the NPP contour system are determined - defects in the form of ulcerative corrosion on non-metallic inclusions. The mechanism of formation and development of defects is established. It is shown that damage in the parking conditions of the СТВВС pipeline can develop much faster than operational corrosion. It is dangerous to use pipelines, the metal of which has the maximum allowable contamination of non-metallic inclusions - 4 points levels. For the structure of steel 20 after long-term operation, there is aging, which consists in changing the pearlitic component, i.e. there are processes of redistribution of carbon in phases, which is also confirmed by the method of internal friction. Using the data of long-term eddy current testing of heat exchange pipes of PGV-1000 steam generators at the power units of the South-Ukraine NPP, defect formation in the heat exchanger is considered taking into account the results of new metallographic researches. Features of distribution of defects on ECT (eddy current testing) characteristics (signal amplitude, "metal loss") are found. It is shown that the nuclei of damage in the metal can be non-metallic inclusions, which initiate the processes of local corrosion and corrosion fatigue. The conducted analysis can be used to improve the regulations and plans of regular inspections at NPPs. Product Description popup.authors Vasylenko Ruslan L Voievodin Viktor M Hozhenko Serhii V Krainіuk Yevhen O Lisna Valentyna H Mishchenko Pavlo O Mitrofanov Anatoliy S Savchenko Volodymyr I Shapoval Ivan M popup.nrat_date 2021-01-11 Close