Features of the fracture of the control valve rod of a thermal power plant steam turbine

Krechkovska, Halyna

doi:https://doi.org/10.35784/ visnyk_tntu2026.02.063

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Πεδίο DC	Τιμή	Γλώσσα
dc.contributor.author	Krechkovska, Halyna
dc.date.accessioned	2026-10-13T08:48:21Z	-
dc.date.available	2026-10-13T08:48:21Z	-
dc.date.created	2026-05-26
dc.date.issued	2026-05-26
dc.date.submitted	2025-12-29
dc.identifier.citation	Krechkovska H. Features of the fracture of the control valve rod of a thermal power plant steam turbine / Halyna Krechkovska // Scientific Journal of TNTU. — Tern. : TNTU, 2026. — Vol 122. — No 2. — P. 63–69.
dc.identifier.issn	2522-4433
dc.identifier.uri	http://elartu.tntu.edu.ua/handle/lib/54174	-
dc.description.abstract	The reasons for the failure of the steam turbine control valve rod after 17 years of operation were analyzed. It was found that its fracture began in several places along the perimeter of the rod, followed by coalescence and subsequent spontaneous failure. Fractographic analysis showed that the crack propagated via a high-temperature fatigue fracture mechanism. Impact toughness, strength, and ductility properties determined on axial steel specimens of the control valve rod complied with regulatory requirements. However, the parameters of transverse specimens made from the rod head were lower. A decrease in all these characteristics was also observed in the high-temperature operating zone compared to the low-temperature zone, indicating more intense metal degradation. The control valve rod had 12091 operating hours and 206 shutdowns, which significantly impacted this process. Macrofractographic analysis showed that the rod fracture occurred because of multiple microcrack initiation in the nitrided layer along the perimeter in the zone of the fillet transition (stress concentrator) between the conical part and the head. Further growth of cracks into the depth of the section and their merging led to sudden fracture. Microfractographic studies confirmed the fatigue mechanism of crack initiation under low-amplitude cyclic loading. At the initial stage, characteristic fatigue grooves were observed, corresponding to the second section of the fatigue kinetic diagram. Their results showed that at a temperature of 540°C, the crack growth rate was 5·10⁻⁸ m/cycle. The rod fracture occurred due to multi-cycle fatigue, and only at the final stage did signs of low-cycle fracture appear.
dc.format.extent	63-69
dc.language.iso	en
dc.publisher	ТНТУ
dc.publisher	TNTU
dc.relation.ispartof	Вісник Тернопільського національного технічного університету, 2 (122), 2026
dc.relation.ispartof	Scientific Journal of the Ternopil National Technical University, 2 (122), 2026
dc.relation.uri	https://doi.org/10.6919/ICJE.202411_10(11).0008
dc.relation.uri	http://nbuv.gov.ua/UJRN/Nn_2009_26_68/
dc.relation.uri	https://doi.org/10.15407/pmach2021.04.061
dc.relation.uri	https://doi.org/10.1016/S1044-5803(03)00105-0
dc.relation.uri	https://doi.org/10.1016/j.jmrt.2022.01.020
dc.relation.uri	https://doi.org/10.3389/fmats.2023.1298138
dc.relation.uri	https://doi.org/10.33108/visnyk_tntu2025.04
dc.relation.uri	https://doi.org/10.3390/pr11041106
dc.relation.uri	https://doi.org/10.33108/visnyk_tntu2023.02ISSN2522-4433
dc.relation.uri	https://doi.org/10.3390/ma17051007
dc.relation.uri	https://doi.org/10.5755/j02.mech.14797
dc.relation.uri	https://doi.org/10.1007/s11003-016-9869-5
dc.relation.uri	https://doi.org/10.15407/mfint.41.06.0825
dc.relation.uri	https://doi.org/10.3390/sym17010053
dc.relation.uri	https://doi.org/10.1016/j.compositesa.2015.10.033
dc.relation.uri	https://doi.org/10.1007/s11003-017-9991-z
dc.subject	steam turbine rod
dc.subject	steel
dc.subject	failure mechanism
dc.subject	nitrided surface layer
dc.subject	mechanical properties
dc.subject	loading
dc.title	Features of the fracture of the control valve rod of a thermal power plant steam turbine
dc.type	Article
dc.rights.holder	© Тернопільський національний технічний університет імені Івана Пулюя, 2026
dc.coverage.placename	Тернопіль
dc.coverage.placename	Ternopil
dc.format.pages	7
dc.relation.referencesen	1. Yuan Zhanhong and Zhongjin Gao (2024) Analysis and improvement practice for stream control valve rod fracture of back pressure steam turbine. International Core Journal of Engineering, 10, Is. 11, pp. 58–66. https://doi.org/10.6919/ICJE.202411_10(11).0008.
dc.relation.referencesen	2. Tkachuk Yu. M., Student O. Z. (2009) Problems of thermal power engineering of Ukraine: analysis of the causes of damage to steam turbine components. Scientific notes, 26, pp. 329–333. http://nbuv.gov.ua/UJRN/Nn_2009_26_68/. (In Ukrainian).
dc.relation.referencesen	3. Koliadiuk A. S., Shulzhenko M. H., Hubskyi O. M. (2021) Strength and service life of a steam turbine stop and control valve body. J. of Mechanical Engineering – Problemy Mashynobuduvannia, 24, Is. 4, pp. 61–70. https://doi.org/10.15407/pmach2021.04.061.
dc.relation.referencesen	4. Ipohorski M., Luppo M. I., Castillo-Guerra R., Ovejero-Garcı́a J. (2003) Failure analysis of a steam valve rod. Materials Characterization, 50, is. 1, pp. 23–30. https://doi.org/10.1016/S1044-5803(03)00105-0.
dc.relation.referencesen	5. Weng S., Huang Y., Lin S., Xuan F.-Z. (2022)Stress-corrosion crack propagation in nuclear steam turbine rotor steels: effects of microstructure in a simulated environment. Journal of Materials Research and Technology, 17, pp. 725–742. https://doi.org/10.1016/j.jmrt.2022.01.020.
dc.relation.referencesen	6. Du C., Liu C., Li X., Lu J., Yuan J. and Liu B. (2023) Fatigue fracture failure analysis of guide valve based on welding defects. Front. Mater, 10, 1298138. https://doi.org/10.3389/fmats.2023.1298138.
dc.relation.referencesen	7. Solovey P., Krechkovska H., Student O. (2025) Structural-fractographic indicators of operational damage in steam turbine rotor disc steel. Scientific Journal of TNTU, 4 (120), pp. 90–98. https://doi.org/10.33108/visnyk_tntu2025.04. 090.
dc.relation.referencesen	8. Guo F., Lyu Y., Duan Z., Fan Z., Li W., Chen F. (2023) Analysis of regulating valve rod fracture in a petrochemical plant. Processes, 11, 1106. https://doi.org/10.3390/pr11041106.
dc.relation.referencesen	9. Solovei P., Student O., Svirska L., Kurnat I., Krechkovska S., Gural T., (2023) Establishing the causes of premature damage of steam turbine rotor blades of TPP. Scientific Journal of the Ternopil National Technical University, 2, 110. https://doi.org/10.33108/visnyk_tntu2023.02ISSN2522-4433.
dc.relation.referencesen	10. Guiyan Gao, Shusheng Guo and Derui Li. A, (2024) Review of Cavitation Erosion on Pumps and Valves in Nuclear Power Plants, Materials, 17, Is. 5, art. no. 1007. https://doi.org/10.3390/ma17051007.
dc.relation.referencesen	11. Terent V. F., Kolmakov A. G., Kvedaras V., Čiuplys V., Antanas Čiuplys, Vilys J., Baikov A. A. (2007) The effect of nitriding on fatigue strength of structural alloys. Mechanika, 64, is. 2, pp. 12–22. https://doi.org/10.5755/j02.mech.14797.
dc.relation.referencesen	12. Krechkovs’ka H. V. (2016) Fractographic signs of the mechanisms of transportation of hydrogen in structural steels. Materials Science, 51, is.4, pp. 509–513. https://doi.org/10.1007/s11003-016-9869-5.
dc.relation.referencesen	13. Nemchuk O. O., Krechkovska H. V. (2019) Fractographic substantiation of the loss of resistance to brittle fracture of steel after operation in the marine gantry crane elements. Metallofizika I Noveishie Tekhnologii, 41, 6, pp. 825–836. https://doi.org/10.15407/mfint.41.06.0825.
dc.relation.referencesen	14. ISO 148-1:2016, Metallic Materials–Charpy Pendulum Impact Test–Part 1: Test Method. ISO: Geneva, Switzerland, 2016, 29 p.
dc.relation.referencesen	15. ISO 6892-1:2019, Metallic Materials Tensile Testing. Part 1. Method of Test at Room Temperature. ISO: Geneva, Switzerland, 2020, 70 p.
dc.relation.referencesen	16. ISO 7500-1:2018-02, Metallic Materials–Calibration and Verification of Static Uniaxial Testing Machines-Part 1: Tension/Compression Testing Machines–Calibration and Verification of the Force-Measuring Syrod. ISO: Geneva, Switzerland, 2018, 18 p.
dc.relation.referencesen	17. ISO 9513, Metallic Materials–Calibration of Extensometer Syrods Used in Uniaxial Testing. ISO: Geneva, Switzerland, 2012, 45 p.
dc.relation.referencesen	18. Kori T. H., Kassaye F. T., Kozłowska A., Grajcar A. (2025) Numerical Modeling of Charpy Impact Toughness Behavior and Stress Distribution of Quenching and Partitioning Steel, Symmetry 17, 53. https://doi.org/10.3390/sym17010053.
dc.relation.referencesen	19. Michael May (2016) Measuring the rate-dependent mode I fracture toughness of composites – A review, Composites Part A: Applied Science and Manufacturing, 81, pp. 1–12. https://doi.org/10.1016/j.compositesa.2015.10.033.
dc.relation.referencesen	20. Krechkovs’ka H. V., Student O. Z., (2017) Determination of the Degree of Degradation of Steels of Steam Pipelines According to Their Impact Toughness on Specimens with Different Geometries of Notches. Materials Science, 52, is. 4, pp. 566–571. https://doi.org/10.1007/s11003-017-9991-z.
dc.identifier.doi	https://doi.org/10.35784/ visnyk_tntu2026.02.063
dc.contributor.affiliation	Karpenko Physico-Mechanical Institute of the NAS of Ukraine
dc.citation.journalTitle	Вісник Тернопільського національного технічного університету
dc.citation.volume	122
dc.citation.issue	2
dc.citation.spage	63
dc.citation.epage	69
dc.identifier.citation2015	Krechkovska H. Features of the fracture of the control valve rod of a thermal power plant steam turbine // Scientific Journal of TNTU, Ternopil. 2026. Vol 122. No 2. P. 63–69.
dc.identifier.citationenAPA	Krechkovska, H. (2026). Features of the fracture of the control valve rod of a thermal power plant steam turbine. Scientific Journal of the Ternopil National Technical University, 122(2), 63-69. TNTU..
dc.identifier.citationenCHICAGO	Krechkovska H. (2026) Features of the fracture of the control valve rod of a thermal power plant steam turbine. Scientific Journal of the Ternopil National Technical University (Tern.), vol. 122, no 2, pp. 63-69.
Εμφανίζεται στις συλλογές:	Вісник ТНТУ, 2026, № 2 (122)

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