2022 №04 (05) DOI of Article
2022 №04 (01)

Technical Diagnostics and Non-Destructive Testing 2022 #04
Technical Diagnostics and Non-Destructive Testing #4, 2022, pp. 41-46

Mechanical properties of metal of critically thinned sections of heat pipelines and features of their destruction

P.S. Yukhymets1, R.I. Dmytrienko1, O.L. Palienko1, V.M. Yehorenko2

1E.O. Paton Electric Welding Institute of NASU. 11 Kazymyr Malevych str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua
2JV «Kyivteploenergo». 5, Ivan Franko sq., 01001, Kyiv, Ukraine. E-mail: yehorenko.vm@kte.kmda.gov.ua

A comparison of mechanical test results of a pipe metal was conduced depending on the type of sample, the accumulated residual strain and the method of its determination. A comparative assessment of heat pipe strength in the presence of a critically thinned area was performed based on the criteria of static and low-cycle strength. The obtained results proved that changes in the properties of strength and plasticity characteristics of critically thinned areas revealed during mechanical testing contribute to an increase in the probability of low-cycle destruction of the heat pipeline with larger residual thickness. Satisfactory result of periodic hydraulic tests does not exclude the possibility of heat pipeline destruction during the next heating season due to the increase in metal damage of critically thinned areas caused by significant fluctuations of operating pressure. Proposals are provided for determination of hydraulic test pressure of heat pipelines. 17 Ref., 2 Tabl., 8 Fig.
Keywords: heat pipeline, metal mechanical properties, low-cycle strength, hydraulic test

Received: 26.08.2022


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