Персона:
Крымская, Ольга Александровна

Научные группы

Научная группа

Лаборатория рентгеновского текстурного анализа (Кафедра №9)

Организационные подразделения

Организационная единица

Цель ИЯФиТ и стратегия развития - создание и развитие научно-образовательного центра мирового уровня в области ядерной физики и технологий, радиационного материаловедения, физики элементарных частиц, астрофизики и космофизики.

Фамилия

Крымская

Имя

Ольга Александровна

Полная страница элемента

Результаты поиска

Теперь показываю 1 - 10 из 28

Открытый доступ
Thermal resistance of steels with increased strength properties for pressure vessels of advanced VVER reactors of various designs
(2023) Maltsev, D. A.; Исаенкова, Маргарита Геннадьевна; Крымская, Ольга Александровна; Федотов, Иван Владимирович; Кулешова, Евгения Анатольевна; Минушкин, Роман Александрович; Kuleshova, E. A.; Fedotov, I. V.; Isaenkova, M. G.; Krymskaya, O. A.; Minushkin, R. A.
The paper considers the results of structural studies and mechanical tests after a long-term thermal exposure of laboratory heats of the metallurgically improved 15Kh2NMFA steel and steel with an increased content of nickel considered as materials for the pressure vessels of advanced VVER-type reactors of various designs. It has been shown that, both for the improved 15Kh2NMFA steel and the high-nickel steel, there are no signs of grain boundary embrittlement after an segregation provoking embrittlement heat treatment. This is explained by the extremely low grain boundary segregation of phosphorus in the initial state caused by a high degree of the structure dispersity as well as by rather a low content of impurities. Besides, no changes have been found in the yield strength value for the improved 15Kh2NMFA steel, which agrees with the structure investigation results. For the high-nickel steel, a tendency towards a minor yield strength decrease by 5 to 10% and a regular reduction of the critical brittleness temperature has been revealed. A decrease in the mechanical properties has been caused by a relatively low temperature of tempering for the high-nickel steel and, accordingly, by the potential occurrence of the structure recovery during long-term thermal exposure, as evidenced by the results of an X-ray diffraction analysis. Despite the structure recovery in the high-nickel steel under the long-term thermal exposure, the main strengthening carbide phases remain stable. Due to this, the yield strength value remains at a relatively high level that exceeds the values for the modern VVER-type vessel steels, even in the case of a thermal exposure much in excess of the expected operating conditions for advanced VVER reactors. The observed decrease of critical brittleness temperature during the long-term thermal exposure contributes to an increase in the steel resistance to brittle fracture.
Только метаданные
Simulation of the Stamping of Spacing Grid Cells Made of Thin-Walled Zirconium Tubes
(2019) Ivanov, A. V.; Isaenkova, M. G.; Perlovich, Y. A.; Krymskaya, O. A.; Zhuk, D. I.; Stolbov, S. D.; Klyukova, K. E.; Исаенкова, Маргарита Геннадьевна; Крымская, Ольга Александровна
Finite element simulation is used to study the influence of the anisotropy of the properties of thin-walled tubes made of a Zr-1 wt % Nb alloy on the geometric sizes, the residual stresses, and other parameters of spacing grid cells. The anisotropy of the mechanical properties and the initial structural state are shown to substantially affect the cell sizes. The distributions of the axial and tangential residual stresses in a stamped cell are calculated and measured, and their maximum values agree well with each other.
Только метаданные
Conditions for development of regular structure by deformation of metal materials
(2019) Perlovich, Y. A.; Isaenkova, M. G.; Krymskaya, O. A.; Dobrokhotov, P. L.; Исаенкова, Маргарита Геннадьевна; Крымская, Ольга Александровна
© 2019 Author(s).Possibilities of the new X-ray method of Generalized Pole Figures (GPF) are considered. Its applications to different textured metal materials resulted in discovery of unknown important regularities, controlling structure and texture development under their deformation treatment. Diagrams of correlation (CD) between texture pole figures and distributions of strain hardening have the specific structure, typical for most deformed metal materials. Deviations from this structure due to some features of grain deformation behavior are analyzed.
Только метаданные
Effect of Synthesis Conditions on the Structure and Phase Composition of Magnesium Diboride
(2019) Abdyukhanov, I. M.; Tsapleva, A. S.; Borisov, A. V.; Figurovskii, D. K.; Krymskaya, O. A.; Isaenkova, M. G.; Крымская, Ольга Александровна; Исаенкова, Маргарита Геннадьевна
© 2019, Pleiades Publishing, Ltd. Abstract—The effect of synthesis conditions exerted on the phase composition of MgB 2 samples synthesized in a temperature range from 650 to 900°C and the features of the microstructure thereof are studied. It is shown that the maximum processing level of the initial boron and magnesium mixture into magnesium boride MgB 2 with a minimum content of impurity phases of magnesium oxide and higher magnesium borides can be achieved in the samples after annealing in a temperature range from 650 to 750°C for 1 h upon a preliminary compaction pressure amounting to 630–640 MPa.
Только метаданные
Effect of the Crystallographic Texture in the α Phase on the Anisotropy of the Properties of Pseudo-α and (α + β) Titanium Alloy Sheets
(2021) Medvedev, P. N.; Isaenkova, M. G.; Krymskaya, O. A.; Babich, Y. A.; Исаенкова, Маргарита Геннадьевна; Крымская, Ольга Александровна
© 2021, Pleiades Publishing, Ltd.Abstract: The range in which the α-phase texture in hot-rolled sheets made of VT18U, VT41, and VT25U titanium alloys changes is found. Yield strength contours are calculated using the integral α-phase texture parameters. The yield strength anisotropy is shown to decrease with increasing β-phase content to 25 vol %, but it continues to depend on the texture of the α phase.
Только метаданные
The Chemical and Mineral Composition of Particles Precipitated from a Plasma–Dust Layer on the Porthole of the Descend Space Vehicles during The Passage of the Earth’s Atmosphere
(2021) Tugaenko, V. Y.; Ovchinnikov, D. S.; Isaenkova, M. G.; Kargin, N. I.; Krymskaya, O. A.; Timofeev, A. A.; Babich, Y. A.; Исаенкова, Маргарита Геннадьевна; Каргин, Николай Иванович; Крымская, Ольга Александровна; Тимофеев, Алексей Афанасьевич
© 2021, Pleiades Publishing, Ltd.Electron microscopic studies of the surface of the spacecraft descent vehicle (DV) have revealed faceted particles of various shape and size, which are formed when the DV travels through the Earth’s atmosphere at an ultrasonic velocity. The particles are no more than 5 µm in size. An X-ray diffraction analysis of the phase composition of the precipitate on the DVs porthole after their landing showed that the test samples contain the following minerals: сryptohalite—(NH4)2[SiF6]), sal ammoniac—NH4Cl, mullite—Al2SiO5, and other minerals that rarely occur in nature. The paper presents results of electron microscopic and X-ray studies of samples taken from 4 descent vehicles.
Только метаданные
Structural features ensuring the increase of service characteristics of high-nickel steels for pressure vessels of prospective energy-generation reactors
(2022) Kuleshova, E. A.; Isaenkova, M. G.; Krymskaya, O. A.; Minushkin, R. A.; Кулешова, Евгения Анатольевна; Исаенкова, Маргарита Геннадьевна; Крымская, Ольга Александровна; Минушкин, Роман Александрович
Complex structure studies and mechanical tests of low carbon Ni–Cr–Mo–V steels with low and high nickel content (low-Ni and high-Ni steels) were performed. Mechanical tests showed that high-Ni steels in initial state are characterized by higher strength properties and lower values of critical temperature of brittleness in comparison with low-Ni steels. Estimation of input of various structural elements in ensuring yield strength and brittle fracture stress (which is connected with critical temperature of brittleness) was performed. It was shown that increased strength characteristics of high-Ni steels are determined mostly by higher density of nanoscale carbide precipitations and dislocations. It was also shown that lower critical temperature of brittleness of high-Ni steels is associated with lower width of substructural blocks and, consequently, with higher number of barriers to brittle transcrystalline crack propagation. © 2022
Только метаданные
EFFECT OF SUBSTRUCTURAL INHOMOGENEITY ON THE ANISOTROPY OF PHYSICAL AND MECHANICAL PROPERTIES OF TEXTURED MATERIALS
(2022) Isaenkova, M. G.; Krymskaya, O. A.; Исаенкова, Маргарита Геннадьевна; Крымская, Ольга Александровна
Today, anisotropy of the physical and mechanical properties of textured materials is mainly calculated based on average properties of a single crystal and information about the volume percent of grains that have different orientations, which can be determined with the help of distribution function. It is a fact that, in addition to the crystallographic texture, substructural inhomogeneity develops in rolled materials, which manifests itself as a difference in the distortion of the crystalline lattice (hardening) and elastic microstrains in grains belonging to different texture components. Substructural characterization is based on the X-ray method of Generalized Direct Pole Figures, which implies that a full profile of X-ray reflections is registered for different positions of the specimen, i.e. as a direct pole figure is being built. As a result, one can obtain the FWHMs of X-ray lines and elastic microstrains distributed on the stereographic projection. It means that a textured polycrystalline material that has undergone thermo-mechanical treatment is characterized with a certain spectrum of structural states and the presence of residual elastic microstrains. Therefore, the degree of macroscopic anisotropy of the product properties is defined both by the predominant grain orientation in the polycrystal and by the parameters of substructural inhomogeneity of grains belonging to different texture components. In spite of the fact that the elastic properties of an individual crystallite do not change and the tensile and compressive elastic microdeformations are balanced in the studied volume of the material, the elasticity of the whole system, i.e. of a polycrystal, changes due to interacting grains and the elastic energy stored in them. The authors propose a method for calculating elastic moduli and thermal expansion coefficients while accounting for the substructural inhomogeneity of the material by minimizing the elastic energy of the textured material. The efficiency of this method is demonstrated on specimens of a semi-finished channel pipe made of Zr – 2.5% Nb alloy. This research was funded by the Ministry of Science and Higher Education of the Russian Federation; Agreement No. 075-15-2021-1352. © 2022, Ore and Metals Publishing house. All rights reserved.
Только метаданные
STRUCTURE, CRYSTALLOGRAPHIC TEXTURE AND ANISOTROPY OF PROPERTIES OF VZh159 ALLOY AND HOW THEY ARE INFLUENCED BY REGIMES OF SELECTIVE LASER MELTING AND FINAL HEAT TREATMENT
(2022) Rubanov, A. E.; Isaenkova, M. G.; Krymskaya, O. A.; Yudin, A. V.; Исаенкова, Маргарита Геннадьевна; Крымская, Ольга Александровна
This paper examines the effect of scanning strategy (unidirectional scan, island scan and a scan with a 60° turn of the laser beam between layers) during selective laser melting and heat treatment on the crystallographic texture and mechanical properties of VZh159 alloy specimens. Application of different scanning strategies leads to two types of crystallographic texture formed in specimens: the axial component <100> gets reinforced in the unidirectional strategy, while it is the texture component {100}<001> in the other cases. After printing, the specimens were subjected to different regimes of heat treat-ment. They included quenching from 1,100° C; quenching from 1,100° C and ageing at 800 and 700° C; quenching from 1,100° C and ageing at 900, 800, 700 and 650° C. When heat treatment (ageing) tests are conducted at room temperature, it leads to increased yield point and strength as a result of se-condary phase precipitation at grain boundary and in grain core, while pla-sticity drops. During high temperature tests, no strength gain was found after heat treatment. In all heat treatment regimes, the authors observed anisotropy of mechanical properties in the specimens caused by the crystallographic texture that remains after heat treatment. The maximum strength and yield point were detected at 45° load application to growth direction during printing. At the same time, the anisotropy of yield point does not change during high temperature mechanical testing (at 850° C) and has no dependence on the amount of additional precipitates. It suggests that crystallographic texture plays a defi-ning role for anisotropy of properties. The research was conducted under financial support of Russian Federation presented by the RF Ministry of Science and Higher Education (Agreement No. 075-15-2021-1352). © 2022, Ore and Metals Publishing house. All rights reserved.
Только метаданные
CRYSTALLOGRAPHIC TEXTURE AND STRUCTURE FORMED IN ROLLED SHEETS OF ZIRCONIUM ALLOYS DURING ANNEALING
(2022) Klyukova, K. E.; Isaenkova, M. G.; Krymskaya, O. A.; Fesenko, V. A.; Исаенкова, Маргарита Геннадьевна; Крымская, Ольга Александровна; Фесенко, Владимир Александрович
This paper examines the processes of recrystallization in sheets of Zr – 2.5% Nb alloy rolled down to a 50–90% deformation and annealed at 610oC for 1, 3 and 5 hours. The heating rate varied from 10 to 100oC/min. With the help of X-ray structure and texture analysis, the authors looked at optimizing the crystal structure of the deformed alloy while examining changes in the crystallographic texture. It was established that annealing of Zr – 2.5% Nb alloy sheets performed at the temperature that corresponds to the dual phase region α + β of an equilibrium phase diagram also leads to recrystallization, as it happens when applying the annealing temperature of 580oC. However, an 11% increase in the concentration of the additional phase suppresses changes in the crystallographic texture, which may be due to the predominant precipitation of β-zirconium at grain boundaries. At the same time, the growth of recrystallized grains still follows the main regularities of orientation: the orientation of growing grains corresponds to the texture maximum slopes of the direct pole figure (0001); an increased pole density was observed on the difference charts of the direct pole figure (10.0), which is indicative of the presence of grains that are disoriented to the deformed matrix at 30o around the base normals. It is shown that the contribution of the above mentioned processes is determined by the type of initial texture, the annealing temperature, the heating rate and the amount of β-phase. An extended annealing time (from 1 to 5 hours) at the temperature of the dual phase region does not cause any significant change in the crystallographic texture.