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Название Study of the hydrogenation effect on the structure and flattening of tubular samples of PT-7M titanium alloy
DOI 10.17580/tsm.2021.04.12
Автор Khlybov A. A., Ryabov D. A., Pichkov C. N., Shishulin D. N.
Информация об авторе

Nizhny Novgorod State Technical University n. a. R. E. Alekseev, Nizhny Novgorod, Russia:

A. A. Khlybov, Head of the Chair for Materials Science, Materials Technology and Heat Treatment of Metals, Doctor of Engineering Sciences, Professor, e-maill: hlybov_52@mail.ru
D. A. Ryabov, Graduate Student, Juniour Researcher of the Chair for Materials Science, Materials Technology and Heat Treatment of Metals, e-mail: ryabovdm1996@gmail.com


JSC OKBM Afrikantov, Nizhny Novgorod, Russia:
C. N. Pichkov, Head of the Department for System Development of Reliability and Safety of Nuclear Installations
D. N. Shishulin, Head of the Division No. 130, e-mail: shishulin@okbm.nnov.ru


In this work, we analyze the effect of hydrogen embrittlement on the performance of PT-7M titanium alloy products. The above examples show that PT-7M titanium alloy products with a high hydrogen content are prone to cracking, the probability of their destruction increases. In the initial state, the samples were annealed in vacuum at 680 о. Hydrogenation of the samples was carried out by the diffusion method at room temperatures to concentrations of 0.002, 0.005 and 0.01 % (by mass) in a Siverts laboratory setup. The hydrogen content in the samples was determined on a highly sensitive G8 Galileo gas analyzer. To assess the effect of hydrogen embrittlement on the plastic properties and tendency to crack formation, the samples were tested for flattening. The structural state of the alloy was analyzed, which showed that hydride phases were observed to increase with increasing hydrogen concentration. The effect of structural changes in the alloy on the microhardness was studied. The X-ray diffraction analysis also showed the presence of hydride precipitates in the PT-7M alloy. Using the CAE ANSYS engineering complex, a numerical simulation of the stress-strain state of samples was carried out during a flattening test. The simulation results showed that the maximum stresses during flattening exceed the tensile strength. One of the reasons for the hydride phase precipitation is high stresses, which is also confirmed by the results of flattening tests and metallographic analysis: in local zones with an increased level of stresses in the material structure, a higher concentration of the TiHx hydride phase. Flattening tests also showed that the cause of cracking during flattening testing is the presence of brittle hydrides in the structure of the material: cracks are formed by the destruction of hydride phases. In the initial state and with a low hydrogen content (up to 0.002 mass %) no cracks were found in the samples.
Thr research was conducted within the framework of the grant RNF No. 19-19-00332 "Development of scientifically substantiated approaches, hardware and software facilities for monitoring of damage of construction materials, based on the artificial intellect approaches to provide safe operation of technical objects in the Arctic conditions".

Ключевые слова PT-7M titanium alloy, hydrogenation, heat transfer pipes, crack, flattening test, plastic deformation, mechanical stresses
Библиографический список

1. Nochovnaya N. А. Prospects and challenges of application of titanium alloys. Aviation materials and technologies: scientific and technical collection. Issue. “Prospects for development and application of titanium alloys for aircraft, missiles, engines and ships”. Moscow : VIAM, 2007. pp. 4–8.
2. Ushkov S. S., Kozhevnikov О. А. Experience of application and significance of titanium alloys for development of nuclear energy in Russia. Voprosy materialovedeniya. 2009. Vol. 59, No. 3. pp. 172–187.
3. Khlybov А. А., Ryabov D. А., Pichkov S. N., Shishulin D. N., Zakharov D. А. Development of an acoustic method for assessing the influence of the degree of hydrogenation on damage of structures made of titanium alloys. Defektoskopiya. 2019. No. 4. pp. 8–14.
4. Darbinyan О. E., Filimoshkin S. V., Fadeev Yu. P. et. al. Extension of the service life of nuclear icebreaker reactor units. Ensuring security during the extended period. Arktika: ekologiya i ekonomika. 2014. No. 1. pp. 88–95.
5. Karzov G. P., Timofeev B. T., Chernaenko T. A. Ageing of equipment materials for nuclear power stations (NPS) during their design service life. Voprosy materialovedeniya. 2005. Vol. 42. No. 2. pp. 92–110.
6. Ilin А. А., Kolachev B. А., Polkin I. S. Titanium alloys. Composition, structure, properties: reference book. Moscow : VILS – MATI, 2009. 520 p.
7. López-Suárez A. Effect of absorption and desorption of hydrogen in Ti and Ti alloys. New Advances in Hydrogenation Processes – Fundamentals and Applications. 2017. pp. 209–225.
8. Silverstein R., Eliezer D., Tal-Gutelmacher E. Hydrogen trapping in alloys studied by thermal desorption spectrometry. Journal of Alloys and Compounds. 2018. Vol. 747. pp. 511–522. DOI: 10.1016/j.jallcom.2018.03.066.

9. Qi-gang Weng, Rui-di Li, Tie-chui Yuan, Yu-sheng Shi, Zi-li Qiu. et al. Hydrogenation reaction of metallic titanium prepared by molten salt electrolysis. Transaction of nonferrous metals society of China. 2016. Vol. 26. pp. 1425–1432.
10. Kolachev B. А. Hydrogen brittleness of metals. Moscow: Metallurgiya, 1985. 216 p.
11. Livanov V. А., Bukhanova А. А., Kolachev B. А. Hydrogen in titanium. Moscow : Metallurgiya, 1962. 246 p.
12. Myuller V. Metal hydrides. Moscow: Atomizdat, 1973. 281 p.
13. Trunov N. B., Denisov V. V., Bergunker V. D. Et. al. Ensuring the safety, reliability and service life of the NPP VVER tube bundle. 3d International conference on security of the NPP with VVER. Podolsk, 2003. Vol. 2. pp. 195–222.
14. Deriy V. P., Semenov V. К., Shchebnev V. S. On the issue of forecasting the reliability and resource of NPP tubes with VVER. Izvestiya vuzov. Yadernaya energetika. 2007. No. 2. pp. 58–63.
15. Bakhmetyev А. М., Sandler N. G., Bylov I. А., Baklanov А. V. еt. al. Ana lysis of possible causes and mechanisms of failures of pipe systems of steam generators of nuclear vessels. Arktika: ekologiya i ekonomika. 2013. Vol. 11, No. 3. pp. 97–101.
16. Kozhevnikov О. А., Mikhaylov V. I., Mezhonov V. А., Ushkov S. S. Prospects for the use of low-activation titanium alloys in welded structures of nuclear power plants. Voprosy materialovedeniya. 2007. Vol. 51, No. 3. pp. 50–60.
17. GOST 22897–86. Seamless cold-deformed pipes from alloys based on titanium. Specifications. Introduced: 1988-01-01. Moscow : IPK Izdatelstvo standartov, 1997.
18. Stepanova, E. N., Kudiyarov V. N., Sypchenko V. S., Lider A. M., et al. Research of hydrogenation and dehydrogenation effect on the structural and phase state of the titanium alloy. Key Engineering Materials. 2016. Vol. 683. pp. 187–192. DOI: 10.4028/www.scientific.net/KEM.683.187.
19. Kaplun A. B., Morozov Е. М, Shamraeva М. А. ANSYS in the hands of an engineer. A practical guide. Moscow : Librokom, 2015. 270 p.
20. Chernov I. P., Lider А. М., Cherdantsev Yu. P. et. al. Hydrogen-induced defects in titanium. Fizicheskaya mezomekhanika. 2000. Vol. 6, No. 3. pp. 97–103.
21. Moroz L. S., Chechulin B. B. Hydrogen brittleness of metals. Moscow: Metallurgiya, 1967. 255 p.
22. Eremenko V. N. Titanium and its alloys. Kiev : Izdatelstvo AN Ukrainskoy SSR, 1960. 499 p.
23. Kornilov I. I. Titanium. Sources, compositions, properties, metal chemistry and application. Moscow : Nauka, 1975. 310 p.

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