National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, Russia:

Aung Kyaw Zaw, Post-Graduate Student
I. I. Chernov, Professor, e-mail: i_chernov@mail.ru
M. S. Staltsov, Assistant Professor
B. A. Kalin, Professor, Head of a Chair of Physical Problems of Material Science
O. N. Korchagin, Post-Graduate Student

Using a transmission electron microscope and gas analyzer RHEN-602, microstructure development peculiarities and hydrogen retention were investigated in vanadium-based alloys, depending on chemical composition and concentration of alloying elements in vanadium (V – Ti, V – Ta and V – W alloys). Samples were sequentially implanted by helium and hydrogen ions, and were saturated by hydrogen in autoclave without introduction of radiation defects. There was established the minimum amount of hydrogen at concentrations of few tenths of titanium weight percent for both methods of hydrogen introduction into V – Ti alloys. Amount of retained hydrogen is increased substantially with increasing of titanium concentration above 1% (wt.). Vanadium alloying by tantalum and tungsten decreases the amount of retained hydrogen in alloys by almost two times, in comparison with its capture by vanadium. High density of fine bubbles is formed from helium-vacancy complexes under irradiation with H⁺ ions of samples, implanted by He⁺ ions at 290 K. Irradiation by H⁺ ions of samples, implanted by He⁺ ions at 920 K, accompanied by helium porosity formation, leads to radiation-induced dissolution of some bubbles and growth of others in local volumes of samples. Thus, sequential introduction of helium and hydrogen, accompanied by helium bubbles formation, leads to increase of hydrogen retained amount. Obtained results may be useful in development of reactor structural vanadium alloys, as well as in evaluation of possibility of hydrogen embrittlement of vanadium alloys during operation in reactor conditions.

1. Vatulin A. V. Maloaktiviruemye konstruktsionnye materialy dlya yadernoy tekhniki (teplovydelyayushchaya sborka yadernoy energeticheskoy ustanovki) (Low-activated structural materials for nuclear plant (fuel assembly of nuclear power facility)). Voprosy atomnoy nauki i tekhniki. Seriya: Materialovedenie i novye materialy = Problems of atomic science and technology. Series: Material Science and new materials. 2004. Iss. 1(62). pp. 26–41.
2. Lyublinskiy I. E., Vertkov A. V., Evtikhin V. A., Votinov S. N., Gubkin I. N., Karasev Yu. V., Dedyurin A. I., Borovitskaya I. V., Kalashnikov A. N. Optimizatsiya legirovaniya splavov sistemy V – Ti – Cr (Optimization of alloying of V – Ti – Cr system alloys). Voprosy atomnoy nauki i tekhniki. Seriya: Termoyadernyy sintez = Problems of atomic science and technology. Series: Thermonuclear fusion. 2005. Iss. 3. pp. 70–78.
3. Ivanov L. I., Platov Yu. M. Radiatsionnaya fizika metallov i ee prilozheniya (Radiation physics of metals and its applications). Moscow : Nauka, 2002. 300 p.
4. Blokhin D. A., Chernov V. M. Yadernoe obrazovanie vodoroda i geliya v konstruktsionnykh materialakh energeticheskikh reaktorov deleniya i termoyadernogo sinteza (Nuclear formation of hydrogen and helium in structural materials of energetic fission and fusion reactors). Voprosy atomnoy nauki i tekhniki. Seriya: Materialovedenie i novye materialy = Problems of atomic science and technology. Series: Material Science and new materials. 2008. Iss. 2 (71). pp. 112–122.
5. Aoyagi K., Torres E. P., Suda T., Ohnuki S. Effect of hydrogen accumulation on mechanical property and microstructure of V – Cr – Ti alloys. Journal of Nuclear Materials. 2000. Vol. 283–287. pp. 876–879.
6. Torres P., Aoyagi K., Suda T. Watanabe S., Ohnuki S. Hydride formation and fracture of vanadium alloys. Journal of Nuclear Materials. 2002. Vol. 307–311. pp. 625–629.
7. Kalin B. A., Staltsov M. S., Chernov I. I. Maloaktiviruemye vanadievye splavy dlya yadernoy i termoyadernoy energetiki: printsipy legirovaniya, radiatsionnaya stoykost, problema geliya i vodoroda (Low-activated vanadium alloys for nuclear and thermonuclear energy: principles of alloying, radiation resistance, problem of helium and hydrogen). Yadernaya fizika i inzhiniring = Nuclear physics and engineering. 2011. Vol. 2, No. 4. pp. 320–344.
8. Chernov I. I., Staltsov M. S., Kalin B. A., Mezina O. S., Kyi Zin Oo, Chernov V. M. Mechanisms of helium porosity formation in vanadium alloys as a function of the chemical composition. Atomic Energy. 2011. Vol. 109, No. 3. pp. 176–183.
9. Reed D. A review of recent theoretical developments in the understanding of migration of helium in metals and its interaction with lattice defects. Radiation Effects. 1977. Vol. 31, No. 3. pp. 129–147.
10. Donnelly S. The density and pressure of helium in bubbles in implanted metals: a critical review. Radiation Effects. 1985. Vol. 90, No. 1/2. pp. 1–47.
11. Chernov I. I., Kalin B. A., Kalashnikov A. N., Anan'in V. M. Behavior of ion implanted helium and structural changes in nickel-base alloys under longtime exposure at elevated temperatures. Journal of Nuclear Materials. 1999. Vol. 271/272. pp. 333–339.
12. Myers S. М., Besenbacher F., Bettiger J. Deuterium He-implanted Fe: trapping and the surface permeation barrier. Applied Physics Letters. 1981. Vol. 39. pp. 450–452.
13. Anan'in V. M., Kalin B. A., Korchagin O. N., Staltsov M. S., Cernov I. I. Investigation of oxygen–titanium interaction in vanadium by internal friction method. Inorganic Materials: Applied Research 2012. Vol. 3, Nо. 3. pp. 243–247.
14. Ruzinov L. P., Gulyanitskiy B. S. Ravnovesnye prevrashcheniya metallurgicheskikh reaktsiy : spravochnik (Equilibrium transformations of metallurgical reactions : reference book). Moscow : Metallurgiya, 1975. 416 p.
15. Kalin B. A., Platonov P. A., Tuzov Yu. V., Chernov I. I., Shtrombakh Ya. I. Fizicheskoe materialovedenie. Tom 6. Konstruktsionnye materialy yadernoy tekhniki : uchebnik dlya vuzov (Material Science. Volume 6. Structural materials by nuclear technics : tutorial for universities). Under the editorship by B. A. Kalin. Moscow : Publishing House of National Research Nuclear University MEPhI, 2012. 736 p.
16. Kim K.-B., Pyum S.-L. The effect of vacancies on hydrogen diffusivity and solubility in iron. Archiv für das Eisenhüttenwesen. 1982. Vol. 53, No. 10. pp. 397–401.
17. Myers S. M., Follstatdt D. M., Besenbucher E. Trapping and surface permeation of deuterium in H⁺-implanted Fe. Journal of Applied Physics. 1982. Vol. 53, No. 12. pp. 8734–8744.
18. Gorodetskiy A. E., Zakharov A. P., Sharapov V. M. Vzaimodeystvie vodoroda s vakansionnymi defektami v metallakh (Interaction of hydrogen with vacancy defects in metals). Zhurnal fizicheskoy khimii = Russian Journal of Physical Chemistry A. 1980. Vol. 54, No. 11. pp. 2874–2881.
19. Myers S. М., Picraux S. Т., Stoltz R. E. Hydrogen effects in metals. N. Y.: Metallurgical Society of AIME. 1981. Nо. 4. pp. 87–95.