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The Investigation of Zirconium Alloys Characteristics during the Oxidation in the Gaseous Medium
| Content Provider | Semantic Scholar |
|---|---|
| Author | Azarenkov, Nikolai A. Vasilenko, Ruslan L. Kirichenko, V. G. Potina, T. S. |
| Copyright Year | 2014 |
| Abstract | Nuclear and technological properties of zirconium and alloys based on its resulted widespread and almost choiceless use of them as one of the best materials fuel claddings, chilled by water, steam and steam-water mixture up to 300 350 °C. Still widely used alloys Zr 1%Nb and Zircaloy-2, which successfully work in pressurized water reactors at a temperature of about 300 °C. Requirements to capacity for work of zirconium alloys in water with high parameters are constantly increasing. The creation of new zirconium alloys is impossible without investigating of mechanism and kinetics of processes occurring in corrosive medium under irradiation and voltage, and without investigating various factors that are determine behavior of alloys in water and steam. In the experiments of initial stage of corrosion of zirconium alloys analysis found that on the inner side of the oxide film formed ZrO2 in the monoclinic modification. It was also found that even in the binary alloy of Zr-1,07% Sn under the influence of corrosion formed fine-dyspersated oxides SnO2 in a matrix of ZrO2. The previous obtained data are mainly explained in the temperature range in the beta area of zirconium alloys. It is caused by the fact that the selfdiffusion rate in the α-phase is less than the selfdiffusion rate in the β-phase in about 100 times. Diffusion of impurities in α-Zr for tin, iron and nickel gives low values of the activation energy Q and the diffusion coefficient D0, moreover, that the temperature dependence of the diffusion coefficient in zirconium does not obey the Arrhenius equation. This is related to the α-, β-transformations. Impurity diffusion investigation of α-Zr showed the existence of both vacancy (for Sb and Sn) and interstitial (for Cr, Mn, Fe, Co, Ni, Cu) mechanism. This difference is caused by the low solubility of alloying elements of the second group in α-Zr and the allocation of intermetallic inclusions, migration of which in deformed alloys during thermal annealing in the range 300-800 °C occurs with a sufficiently high speed. The relationship between diffusion and corrosion characteristics of metals and alloys is obvious. The more important experimental parameters and evaluations obtained as a result of corrosion testing of zirconium and its alloys in different active media. Such active media are include water with high parameters, high-temperature steam, oxygen, air. At the same time it is important to consider the diffusion activity of the matrix atoms of zirconium alloys and dopants. Investigation and analysis of the relationship diffusion characteristics of zirconium and its alloys with corrosion processes occurring on the surface alloys with their oxidation in gas air atmosphere at a temperature of about 1000 °C represent the scientific and practical interest. In the analysis of these processes it is advisable to use the method of differential thermal analysis in conjunction with the methods of analysis the structure and phase composition of alloys. The aim of this work was to investigate and analyze the relationship of diffusion characteristics of zirconium and its alloys with corrosion processes, occurring on the surface of alloys at their oxidation in air gas atmosphere at а temperature of about 1000 °С. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://vant.kipt.kharkov.ua/ARTICLE/VANT_2014_2/article_2014_2_97.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
