[en] The work is devoted to analysis of the experimental results of study creep velocity behavior on the steady-state stage in a wide temperature and stress range. As objects for examination there are aluminium (Al 99.99%), pure copper (Cu 99.99%) and technical copper (Cu 99.95%), copper alloy with 4 at.% of titanium, aluminium alloy D16 and high-nickel alloy 03Kh20N45MBRTs. For an analysis the theoretical model taking into account combined dislocation movement (slip and over-creep) under an interior exert load is applied. It is shown, that the theoretical model and given approach to experimental results processing lead to an unified equation describing reactor and thermal creep velocity

[en] Flat samples of semicrystal copper and aluminium were subjected to creep tests in the WWR-K reactor experimental channel with 1.4x10¹⁶ s^-1xm^-2 neutron flux density. Copper samples were tested at temperatures of 423-773 K and 20-69 MPa stresses (aluminium at 333-473 K, 9.8-24.5 MPa). Reactor and temperature creep rate dependence for copper and aluminium at a steady stage under different test conditions were determined. Three areas with different inclination and energy activation were observed on this dependence curve. Energy activation of copper reactor and thermal creep is constant in one area and changes by transition into another one. Reactor creep energy activation at a temperature of T≤0.4T_melt is significantly less as compared to thermal one

[en] The work presents the results of experimental study of influence of previous reactor irradiation on characteristics of creep and yield stress of 12Cr18Ni10Ti stainless steel. The investigations have shown that conditions of irradiation (in stressed state or limp state) significantly influence on value of yield point and creep rate at temperature 2,800...4,200 deg. with voltage 1.9...2.2 σ02. (σ02 -yield stress). Experimental study of the temperature dependence of creep rate on the fixed stage has allowed to determine the peculiarities of its behavior and the role of previous study conditions. It was shown that irradiation in stressed state (when voltage is lower than yield point) leads to the material weakening. In the case of irradiation in the limp state the situation is vice versa, i.e. irradiation leads to the material strengthening. As a result of the carried out processing of experimental data there was obtained an equilibration describing the connection between creep rate, yield point, active voltage, testing and melting temperature. (author)

[en] The work is devoted to search for a connection between parameters characterizing short-time and long-duration mechanical properties of a crystalline solid. In this case its are: fluidity limit σ₀₂, stress σ, melting temperature T_melt and testing temperature T and creep velocity ε. In the work the one component metals: aluminium (Al 99.99 %), pure copper (Cu 99.99 %) and technical copper (Cu 99.95 %), copper alloy with 4 at.% of titanium, aluminium alloy D16 and high-nickel alloy 03Kh20N45MBRTs were examined. Testing on creep is carried out at one-axis expansion, constant and variable load, stress and temperature at the WWR-K reactor core and at a laboratory conditions (thermal creep). During experimental study the dependences of creep velocity on the steady-state from stress and temperature within the 0.3-0.6T_melt range were determined. There is examined creep velocities domain from 8·10^-10 to 5·10^-7 s^-1

[en] We attempted to find the coupling between parameters which characterized the short lived and prolonged mechanical properties of crystal solid. It is yield strength, σ₀₂, tension σ, temperature T_melt, and testing, T, and steady creep rate, ε. We researched polycrystal aluminum (Al 99.99%), pure (Cu 99.99 %) and technical copper, alloys: copper with 4% titanium, D16 and 03X20H45M4BRTs. The creep testings were conducted during uniaxial tension in reactor core WWER-K in laboratory scale (thermal creep). Yield strength was determined for every sample according to stress stain graph which dumped during sample loading

[en] The material of the fuel assembly shroud which lengthy has been irradiated in BN-350 reactor core was examined. The samples were cutting from a different levels of shroud and representing the plates with sizes of 50x10x2 mm². The examinations show that the irradiation dose and temperature-force conditions in considerable rate influence on specific density change. These differences under irradiation lead to change of material density by all three coordinates. It is established that maximal material density change does not coincide with the reactor core center and it is placed somewhat below of it

[en] The deformation behaviors of some pure metals and alloys during the in-reactor and thermal tests are studied has brought to light the keen necessity for the research of the shortening of creep test duration. The scientific and practical interest require that. The research of relationship in between short and long-time mechanical behavior of solid state crystals had been performed

[en] The experimental results of study of creep for aging 03Kh20N45M4BRTs and D16 alloys were presented. The samples were generated under condition of one-axis expansion and stress. Reactor experiments were conducted at the WWR-K vertical channels in the specially designed remote devices

[en] Full text: A number of phenomena occur in constructional reactor materials during operation under the influence of neutron radiation, temperature and load. One of such phenomena, which result in modification of physical-chemical and mechanical properties, is the redistribution of the mixed and alloying elements. Now the segregative processes in steel and alloys arisen from interaction of load, temperature and corrosive medium have been enough studied. Using the raster electron microscope and the energy dispersion microanalyser we have investigated the samples from the high-nickel alloy Cr20Ni45Mo4 by Zr subjected to intra-reactor creep test and load durability test at higher temperatures. There were studied the distribution of alloying elements in near-surface layer and in grain boundaries depending on deformation degree. In contrast to other investigations, where the element composition is determined from the sample surface the element composition investigation was carried out on depth of near-surface layer about some 50 μm with interval 1-2 μm in this work. It was set that the change of element composition varies on the length of the sample and depends on the deformation degree. The neutron irradiation leads to increasing of silicon, iron and chrome concentration in near-surface layer and in grain boundary

[en] In the work the experimental results on 03Cr20Ni45Mo4BRTs and 03Cr20Ni32Mo5BRTs chemical content change after outside and inside reactor tests on creep at 600 Deg. C. are presented. Analysis of chemical content of examined alloys was carried out with the help of power-dispersion microanalyzer allowing to conduct the analysis of local sections with sizes up 100 Angstrom. The results of examination of irradiated and non-irradiated materials show, that the molybdenum and chromium migration to sample surface is occurring. Conditionally it is possible to allocate three areas: the enriched by chromium area - surface layer; the depleted by chromium area and the unchanged chemical content area. It is noted, that in the irradiated samples the doping elements redistribution effect in a several times higher than in the non-irradiated ones