Vinogradov D. Influence of the structural state on the processes of contacting the hydrogen with zirconium and its alloys

The thesis is devoted to the interaction of hydrogen with zirconium and its alloys, depending on their structural state. The interaction of hydrogen with zirconium, zirconium-nickel and Zr-V alloys in various structural states from nanocrystalline to large crystalline has been investigated. It was found that the temperature of the start of the absorption, the phase composition and the amount of absorbed hydrogen significantly depend from the structural state of zirconium and its alloys. It is shown that the best of the alloys studied is the alloy Zr0.6Ni0.4 (Zr-30 wt.% Ni), which is in the crystalline state. It reabsorbs about 1.68% by weight of hydrogen and has a low activation temperature (about 420 K). It is shown that the sorption-desorption characteristics of cast alloys Zr0.6Ni0.4 and Zr-V are better than the fast-hardened alloys, respectively. Based on the obtained data on the role of oxygen in the interaction of zirconium alloys with hydrogen, the method of protection of fuel rods from Zr alloy - 1% Nb from the formation of hydrides in them by heat treatment of tubes in oxygen-containing media is proposed and implemented. Such treatment will reduce the probability of delayed hydride destruction during the operation of the fuel rods and increase their wear resistance by significantly increasing the hardness of the surface layers of the fuel rods. Key words: zirconium, hydrogen, metal hydrides, hydrogen storage alloys, structural state, sorption-desorption.