Effect of dose and temperature parameters of neutron irradiation to maximum damaging dose of 77 dpa on characteristics of porosity formed in steel 0.07C-16Cr-19Ni-2Mo-2Mn-Ti-Si-V-P-B

The microstructure of samples of cladding tubes made of steel 0.07C-16Cr-19Ni-2Mo-2Mn-Ti-Si-V-P-B (EK164) irradiated to different damaging doses (up to 77 dpa) in the BN-600 reactor at temperatures from 440 to 600°C has been investigated. Characteristics of radiation porosity formed during irradiation in different temperature intervals have been determined. The dependences of the porosity characteristics on the rate of generation of atomic displacements and temperature of neutron irradiation have been established.     

Dependence of the rate of steady-state swelling of fuel-element claddings made of ChS68 steel on the characteristics of neutron irradiation

Rate of steady-state swelling of fuel-element sheaths made of the 06Kh16N15M2G2TFR steel in the course of their operation in a BN-600 reactor has been calculated. In the calculations, the diffusion characteristics of point defects and the results of the determination of the characteristics of the irradiation-induced porosity have been used. The dependence of the dose rate of steady-state swelling on neutron-irradiation characteristics has been analyzed. It has been established that the dose rate of swelling at the steady-state stage is independent of the energy of migration of vacancies and the rate of generation of atomic displacements.     

Characteristics of radiation porosity and structural phase state of reactor austenitic 07C–16Cr–19Ni–2Mo–2Mn–Ti–Si–V–P–B Steel after neutron irradiation at a temperature of 440–600°C to damaging doses of 36–94 dpa

The phase composition and the characteristics of vacancy voids in cold-worked steel 07C–16Cr–19Ni–2Mo–2Mn–Ti–Si–V–P–B (CW EK164-ID) after neutron irradiation at damaging doses of 36–94 dpa and temperatures of 440–600°C are investigated. In the entire range of damaging doses and temperatures, voids with different sizes are observed in the material. The maximum void size increases with irradiation temperature up to ~550°C, whereas their concentration decreases. At higher irradiation temperatures, almost no coarse voids are observed. The concentration of fine voids (to 10 nm in size) sharply increases with temperature from 440 to 480°C. Further increases in the temperature do not result in the noticeable concentration growth. In the irradiation temperature range of 440–515°C, second phases precipitate (G phase, γ’ phase, and complex fcc carbides). At higher irradiation temperatures, there are Laves-phase particles, fine second carbides of the MC type, and needle shape precipitates identified as phosphides in the material.     

Relation between the physicomechanical properties of an austenitic ChS-68 steel and its swelling during high-dose irradiation

The elasticity properties, electrical resistance, swelling, and mechanical properties of the Kh16N15M2GTFR steel irradiated in the BN-600 reactor to a maximum damage dose of 72 dpa are determined. The swelling and the changes in the physicomechanical properties are found to be correlated. The swelling contribution to the changes in the elasticity properties and electrical resistance is calculated and compared to their experimental values. The conditions of the predominant effect of swelling on the physicomechanical properties are revealed. The accuracy of estimating the swelling from the experimental values of electrical resistance and elasticity properties is determined.     

Precipitation-Hardening Austenitic Steel for Fast Neutron Reactors

The properties of conventional stainless reactor steels of the Kh16N15M3 type transformed into precipitation-hardening steels with the help of optimum alloying are studied after irradiation by a flux of fast neutrons. The pore characteristics and the total irradiation-induced swelling are determined. The aging steel Kh16N15MT1 is suggested as a radiation-resistant material for fast neutron reactors.     

Effect of tensile and compressive stresses on the radiation swelling and creep strain in austenitic steel Kh18N10T

Effect of tensile and compressive stresses on the radiation swelling, microstructure, and creep strain in austenitic steel Kh18N10T is considered. The gas-filled samples of a complex shape prepared from steel Kh18N10T were irradiated in a BOR-60 reactor for 2 years to a damaging dose of 15 dpa at a temperature of 420–450°C. In the shells of the irradiated samples, compressive and tensile stresses were created. Samples were also irradiated, in which these stresses practically were absent.     

Acoustic detection of stress-corrosion cracking of nitrogen austenitic steels

Structural changes and resistance to the stress-corrosion cracking of the nitrogen-bearing austenitic steels 04Kh20N6G11M2AFB and 09Kh20N6G11M2AFB (with 0.04 and 0.09 wt % C, respectively) after different treatments, including thermomechanical action, quenching from 1200°C, and aging at 700°C for 2 and 10 h, have been studied. It has been shown that aging at 700°C of the air-melted austenitic steel 09Kh20N6G11M2AFB leads to a decrease in the strength of samples with an induced crack upon the cantilever bending in air and in a 3.5% aqueous solution of NaCl as compared to the strength of the steel 04Kh20N6G11M2AFB-EShP with a smaller carbon content after high-temperature mechanical treatment or quenching from 1200°C. The smallest resistance to stress-corrosion cracking is observed in the samples of 09Kh20N6G11M2AFB steel after 10 h of aging, which is accompanied by the most intense acoustic emission and by brittle intergranular fracture. This is explained by the high rate of the anodic dissolution of the metal near chromium-depleted grain boundaries due to the formation of continuous chains of grain-boundary chromium-containing precipitates of carbides and nitrides.     

Investigation of the structure and properties of the material of various zones of the welded joint of the austenitic nitrogen-containing steel upon elastoplastic deformation

The structural, mechanical, and magnetic properties of metal cut out from the welded joint and from the near-weld zone of the welded joint of high-strength nitrogen-containing 04Kh20N6G11M2AFB austenitic steel have been investigated. The behavior of the magnetic parameters of materials under study subjected to various schemes of loading, such as tension, torsion, internal pressure, and combination of tension and torsion have been investigated. It has been established that the metal of the welded joint and near-weld zone of the welded joint, just as the base metal, has a stable phase composition and magnetic properties under various loading conditions. It has been concluded that 04Kh20N6G11M2AFB steel can be used in the fabrication of welded parts and elements of welded constructions that require low magnetization and high stability of magnetic characteristics under the force action.     

Corrosion-resistant austenitic-ferritic steel 0Kh20N6MD2T

Conclusion The commercially used corrosion-resistant steel 0Kh20N6MD2T can be hardened by aging, without distortion, to a yield point of at least 60kg/mm² and ultimate strength of at least 80 kg/mm² with reduction in section of at least 50%, specific elongation no less than 20%, and impact strength at least 6 kgm/cm² in bar material. In cast material the elongation is at least 15% with the same strength characteristics.The steel has good welding and forming characteristics; it is used for manufacturing welded apparatus of complex shape made by deep drawing.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 71–74, June, 1967.     

Structural state of the claddings of fuel elements of the BN-600 reactor prepared from cold-deformed 16Cr–15Ni–2Mo–2Mn–Ti–V–B steel: Study using the method of high-resolution neutron diffraction

The applicability of the method of high-resolution neutron diffraction for determining defects (dislocations) in the bulk of a material is shown based on the example of a standard sample of deformed copper. The structural state of several samples of fuel-element claddings made of cold-worked steel 16Cr–15Ni–2Mo–2Mn–Ti–V–B (grade ChS68-ID) used in the BN-600 reactor, which were prepared by two producers, i.e., at the PJSC Mashinostroitel’nyi Zavod (MSZ) and at the PJSC Pervoural’sk Novotrubnyi Zavod (PNTZ), have been investigated. The conclusion has been drawn that the claddings have a texture in which the crystallographic planes of grains are oriented along the axis of the shells. It has been shown that the main defects in these claddings are edge dislocations; their density has been determined.     

Low-temperature nitriding of austenitic steel in a vibrofluidized bed

The prospects for use of a vibrofluidized bed (VFB) for low-temperature nitrogen saturation of high-strength austenitic steel based on Cr−Ni−Mn (12Kh17N8G2S2MF) are considered. The positive effect of preliminary plastic deformation on the intensity of nitriding is described. The temperature and time parameters of nitriding in a VFB for strain-aging austenitic steel 12Kh17N8G2S2MF are shown to be adequate for the regimes of the final heat-treatment operation of aging. This creates the possibility of combining the operations of surface alloying and strain aging into a single cycle. This combined treatment increases substantially the resistance of the steel to cyclic loads while preserving the strength parameters. It is shown that the presented method of low-temperature nitriding in a VFB is expedient for improving the service characteristics of austenitic steel 12Kh17N8G2S2MF used for production of force springs of automobile brake systems. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 11, pp. 6–10, November, 1999.     

Relation Between Parameters of Cavitation Resistance and Structure of Steels

The cavitation resistance of steels with different initial structure and hardness (05Kh13, Kh18N10T, St 3, VNS17, 07Kh14AG12M, 12Kh13N3G5, 30Kh13, 03N18K8M5T, 30Kh10G10, 95Kh18, 150Kh12M) is studied. Laws of variation of parameters of cavitation resistance are determined as a function of the level of ultimate hardening of the cavitation-affected surface in the final stage of the incubation period under microimpact loading of the studied steels.__________Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 1, pp. 15 – 19, January, 2005.     

Design and choice of materials for fast reactors with sodium heat-transfer agent

Conclusions We have studied and created structural materials for shell structures (10Kh18N9, 08Kh16N11M3), steam generators (10Kh2M), and HEU jackets (08Kh16N11M3T in a cold-hardened state and 05Kh12N2M) as applied to the working conditions of the equipment of fast reactors. The achievements of the institute have promoted the creation of first-class nuclear power plants on fast neutrons with sodium heat-transfer medium, i.e., Bor-60, BN-350, BN-600, and are being used in erecting a new fast reactor, BN-800. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 9, pp. 24–31, September, 1999.     

Features of Melt Gas Atomization and Selective Laser Melting of High-Strength Austenitic Nitrogen-Containing Steel Powders

Metal Science and Heat Treatment - Preparation of nitrogen-containing steel 04Kh20N6G11M2AFB powder and subsequent selective laser melting (SLM) are studied. The effect of oxygen in the atomizing...     

Technological aspects of assembling‐welding fuel tanks of 1460 and 1570 aluminium alloys

Results are presented on the investigation of the optimization of the temperature–time conditions of high-temperature brazing of structural steels of the austenitic (12Cr18Ni10Ti) and martensitic [06Kh15N6MVFB-Sh (VNS16) and 03Kh12NYuMTR-VD (VNS25)] grades used widely in the manufacture of heat exchangers.     

Analysis of alloying systems of clad stamping tools for cold deformation of metal (review)

Two alloying systems of stamping tools (with intermetallic and carbide hardening) are analysed. Analysis shows the high characteristics of the metal with different alloying systems. The heat resistance of the 100Kh4M5F2(Zr) alloy is not inferior to the R18 high-speed tool steel, and the hardness equals 58–62 HRC as a result of carbide hardening. The relative wear resistance of the 8Kh4GSV2M5F2T alloy was (ε = 2.65), impact toughness (0.28 MJ/m²) and hardness (55 HRC). The highest wear resistance was recorded for the K15M15N5Kh3B2 alloy with the following properties after heat treatment: impact toughness (0.1 MJ/m²) and hardness (39 HRC). The wear resistance is 2–2.5 times higher than that of the R18 high-speed tool steel and 6–6.5 times higher than that of Cr12 and Cr12Mo steels.     

Using friction welding for producing heat exchanger equipment from martensitic 15Kh5M steel

The results of mechanical and other types of tests of metal of welded joints in pipe blanks of 15Kh5M martensitic steel, produced by friction welding with rotation, are presented. On the basis of the analysis of the test results it is concluded that 15Kh5M can be efficiently welded by friction welding and that the method can also be used for producing the tube–tube plate sections of heat exchangers made of 15Kh5M steel with appropriate modernization of welding equipment.     

Special features of welding equipment and pipelines in nuclear power stations made of pearlitic and austenitic steels

In long-term service of dissimilar welded joints (DWJ) in sections connecting equipment and pipelines made of pearlitic and austenitic steels, corrosion damage was observed in the material associated with the intercrystalline corrosion of the metal of the type 10Kh16N24AM6, deposited with UA 395/9 electrodes. The deposited metal of the type 02Kh23N15 is characterized by high corrosion resistance, is not susceptible to hot cracking and can be recommended for the first layer of the load-carrying edges of DWJ.