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Sample records for alloy 800

  1. Spectrochemical analysis of alloy-800

    International Nuclear Information System (INIS)

    An emission spectrographic method for the determination of seven elements in alloy-800 is described. The metal sample is converted to oxide and a 10 per cent carrier mixture (AgCl+LiF+C) is used for the determination of Al, Co, Cu, Mn, Mo and V. 45mg of this (sample + carrier) mixture is taken in a carrier distillation electrode and excited in a d.c. arc. The concentration ranges of the elements determined varies between 200ppm and 0.8 per cent and the coefficient of variation has been found to be around 15 per cent. For the determination of titanium, the sample oxide is glued to the flat tops of a pair of graphite electrodes and excited with a.c. spark. The concentration range covered is 0.35 to 2.0 per cent and the coefficient of variation is found to be ± 3 per cent. (author). 5 figs., 4 tabs

  2. Alloy 800 welding experience at UKAEA Springfields

    International Nuclear Information System (INIS)

    Investigatins into the welding of alloy 800 at the Reactor Fuel Element Laboratories, Springfields, commenced about three years ago following an extended development programme on tube to tube plate welding of low alloy and stainless steels for the Prototype Fast Reactor. The techniques and approach developed for critical fuel element welding applications had proved equally suitable for the precision welding requirements on the much heavier sections of heat exchangers. It had been demonstrated that the same control of weld quality and profile could be achieved with consistency and the permissible range of critical parameters could be readily defined. Because of this, development work was continued to include other materials, such as alloy 800, which might be of potential use. The tungsten inert gas (T.I.G.) arc welding process is used, and the equipment, including the control system, is described. Tube to tube-plate welding, and tube to tube butt welding, are discussed. (author)

  3. Influence of S, P, C on grain boundary diffusion and creep properties of Alloy 800; Einfluss von S, P, C auf die Korngrenzendiffusion und Kriecheigenschaften von Alloy 800

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, J.; Hannesen, K.; Mast, R.; Viefhaus, H. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany); Grabke, H.J.

    1998-12-31

    The paper reports examinations of Alloy 800 and specific commercially available variants known under the names of 800H, 800HT, and 800LC, differing in their concentrations of C, Al, and Ti. In addition, melts also containing phosphorus (0.09 wt-%) or sulfur (0.04 wt-%) as additional alloying materials have been prepared for the experiments. The volume diffusion and the grain boundary diffusion of {sup 59}Fe in those alloys was measured at temperatures between 800 and 1000 C by means of a radioactive tracer method combined with residual activity measurements. It was found that accompanying elements like phosphorus and sulfur increase the activation energy of the grain boundary diffusion of the iron and thus delay the grain boundary self-diffusion in Alloy 800. Creep curves were measured of the same materials after age-hardening treatment for 100 hours at 800 C, measurements performed at constant temperature but at three different, constant creep stress loads. The results showed that addition of phosphorus markedly increases the lifetime of Alloy 800, and reduces the creep rupture strain. The minimum strain rate in Alloy 800 containing 0.09 wt-% of phosphorus was found to be lower by a factor of 100, as compared to the other Alloy 800 materials used. (orig./CB) [Deutsch] Alloy 800 ist ein austenitischer Fe-Ni-Cr Stahl, der relativ geringe, aber wichtige Konzentrationen von Kohlenstoff, Aluminium und Titan enthaelt. Besondere Varianten von Alloy 800, bekannt als 800H, 800HT und 800LC, unterscheiden sich in den Konzentrationen dieser Elemente. Diese kommerziellen Legierungen wurden untersucht, und zusaetzlich wurden Schmelzen mit zulegiertem Phosphor (0,09 Gew-%) bzw. Schwefel (0,04 Gew-%) hergestellt. Mittels einer radioaktiven Tracermethode in Verbindung mit Restaktivitaetsmessungen wurde die Volumen- und Korngrenzendiffusion von {sup 59}Fe in diesen Legierungen im Temperaturbereich 800-1000 C gemessen. Es wurde gefunden, dass Begleitelemente wie Phosphor und

  4. Formation of epsilon martensite phase in cold worked alloy 800

    International Nuclear Information System (INIS)

    Fe-Ni-Cr based Alloy 00 is an austenitic, precipitation-hardenable alloy. It is widely used as a steam generator (SG) tube material in nuclear power plants (NPPs). Trouble-free operation of NPPs depends to a great extent on the uninterrupted operation of SGs those are large heat-exchangers. To reduce the number of SG tube failures, it is of importance to comprehend material, environment and their compatibility. Microstructure is decisive quite often in controlling the properties of the materials. Since SG tubes are used in hairpin shape in some cases, microstructural aspects of SG tube materials in severely deformed states are to be understood in a comprehensive manner. This paper highlights the microstructural features of Alloy 800 in severely cold worked states along with the mill-annealed one

  5. Oxidation behavior of steels and Alloy 800 in supercritical water

    International Nuclear Information System (INIS)

    The oxidation behavior of a ferritic-martensitic steel T91 and a martensitic steel AISI 403 up to 750 h, and of AISI 316L and Alloy 800 up to 336 h in deaerated supercritical water, 450ºC-25 MPa, was investigated in this paper. After exposure up to 750 h, the weight gain data, for steels T91 and AISI 403, was fitted by ∆W=k tn, were n are similar for both steels and k is a little higher for T91. The oxide films grown in the steels were characterized using gravimetry, scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and X-ray diffraction. The films were adherent and exhibited a low porosity. For this low oxygen content supercritical water exposure, the oxide scale exhibited a typical duplex structure, in which the scale is composed of an outer iron oxide layer of magnetite (Fe3O4) and an inner iron/chromium oxide layer of a non-stoichiometric iron chromite (Fe,Cr)3O4. Preliminary results, with AISI 316L and Alloy 800, for two exposure periods (168 and 336 h), are also reported. The morphology shown for the oxide films grown on both materials up to 336 h of oxidation in supercritical water, resembles that of a duplex layer film like that shown by stainless steels and Alloy 800 oxide films grown in a in a high temperature and pressure (220-350ºC) of a primary or secondary coolant of a plant. (author)

  6. The oxidation behavior of three different zones of welded Incoloy 800H alloy

    International Nuclear Information System (INIS)

    Highlights: • The oxidation kinetics of 800H followed the parabolic-rate law in dry-air. • The scales formed on the alloys were composed of Cr2O3 and MCr2O4 (M = Fe, Cr). • Internal-oxidation of Al2O3 and SiO2 dissolved Ti were observed in 800H-SUB and 800H-HAZ • The weight loss behavior of 800H-SUB and 800H-HAZ were observed in wet air. • The mass-loss behavior of 800H-HAZ is more severe than 800H-SUB in wet air. - Abstract: The oxidation behavior of three different zones of welded Incoloy 800H alloys, containing the substrate (800H-SUB), heat-affected zone (800H-HAZ) and the melt zone (800H-MZ) was studied at 950 °C in dry and wet air. The steady-state oxidation rate constants (kp values) were calculated based on the mass-gain data, and the oxidation resistant ability of the alloys followed by the rank of 800H-MZ > 800H-SUB > 800H-HAZ in dry air. The scales formed on the 800H-SUB and 800H-HAZ consisted of a heterophasic mixture of Cr2O3 and FeCr2O4, while a mixture of Cr2O3 and MnCr2O4 was observed on the 800H-MZ. On the other hand, the oxidation kinetics of the alloy, initially followed the parabolic-rate law up to 48 h, while a significant mass-lost kinetics was observed for a prolong exposure in wet air. The detail oxidation mechanisms for the alloys in both environments were investigated

  7. Analytical representation of the creep and creep-rupture behavior of Alloy 800H

    Energy Technology Data Exchange (ETDEWEB)

    Booker, M.K.

    1978-01-01

    The extensive use of Alloy 800 (including the 800H variation) in elevated-temperature applications requires that the mechanical properties of this material be well characterized and understood. In the present investigation, available creep and creep-rupture data for Alloy 800H have been collected and analyzed. Results include mathematical models describing time and strain to rupture, time and strain to tertiary creep, and creep strain-time behavior as functions of stress and temperature.

  8. Corrosion of alloy 800 in PHWR primary and secondary conditions

    International Nuclear Information System (INIS)

    A hot leg section of a steam generator tubing was removed for destructive examination from one of the steam generators (SG) of the Embalse Nuclear Power Plant. The tube material is Alloy 800 and carbon steel is the tube support plate material. Samples of the deposits were taken at the first tube support plate and at the top, mid-height and bottom of the sludge pile. Transverse sections were taken at several locations along the tube length measuring the oxide thicknesses and studying the morphology of the oxide layer by scanning electron microscopy on the primary and secondary side at each location. Deposit layers on the outer tube surface revealed iron as major component and the presence of calcium, phosphorous, zinc and manganese. The oxide scale thickness at the secondary side in the open area was around 22 to 30 μm. The oxide thickness grown under isothermal conditions on the corrosion test samples installed in the autoclaves facilities of the primary circuit of the plant was measured and compared with that found on the inner surface of the examined tube section. The oxide thickness of the test samples was around 1-2 μm showing the influence of the deposition of corrosion products from the coolant. Deposition and precipitation of oxide was also found in the actual tube, where the common feature was the irregularity of the oxide layer on the primary side and thicknesses values in the range 4 to 10 μm were measured. The autoclave tests and SG tubing examination permit to compare the influence of materials and of operating (flow rate, isothermal vs non-isothermal) conditions on corrosion and deposition. (author)

  9. Creep performance and microstructure of the iron alloy Alloy 800 HT

    International Nuclear Information System (INIS)

    The examination of the high-temperature properties of the alloy Alloy 800HT has shown that both the creep performance and the microstructure of the material can be purposefully set by the initial heat treatment. At the high temperatures applied, (700-900 C), a rapid softening process sets in induced by carbide precipitation, stabilization, and coarsening. This softening process causes creep velocities strongly accelerating as a function of duration of the heat treatment prior to the creep test. The identified cause of the softening effect is a change in particle size that could be verified by SEM and TEM. It is shown that two different carbide precipitate size classes are responsible for the softening effect. While the precipitates dectable by TEM become effective primarily via interactions with dislocations, the carbide precipitates detectable only by SEM contribute to a hardening of the grain boundaries and the matrix.(orig./CB)

  10. Comparison of mechanical and corrosion behaviour of Alloy 800 H and the new alloy AC 66

    International Nuclear Information System (INIS)

    In coal gasification plants based on nuclear process heat, materials are subjected to high temperature corrosion in process gas atmosphere at 750 to 900 deg. C. The process gas consists of steam, CO, CH4, CO2 and, depending on the gasified coal, low or high H2S-concentrations. The service problems can be divided as follows: 1. Gas-metal interaction: (a) high temperature corrosion; (b) sulphidation; (c) carburization; (d) internal oxidation or internal sulphidation. 2. Ash (slag)-metal interaction: (a) corrosion in molten salts; (b) erosion. 3. Mechanical loading: (a) embrittlement; (b) thermal fluctuations/strain fluctuations; (c) low cycle fatigue; (d) high temperature creep. Therefore materials for heat exchangers must be resistant to these types of high temperature corrosion and they should also have adequate creep rupture strength. Some commercial alloys and various model alloys were exposed to a process gas atmosphere to determine the corrosion behaviour and also stressed mechanically to investigate the interaction of high temperature creep behaviour and corrosion. The tests were carried out for a total period of 10,000 h and specimens were taken out after periods of 1000, 3000, 5000 and 10,000 h. A programme for the development of alloys was started with the aim of optimizing the chemical composition resulting in a good high temperature corrosion resistance and adequate mechanical properties, particularly high creep strength. However, the material must be such that it can be deformed to tubes. Compared with Incoloy 800, one of the new and optimized model alloys (30-32% Ni, 25-27% Cr, and Ce, Fe-balance) exhibits a very good corrosion resistance even when sulphur rich coal is gasified. The creep rupture strength at 900 deg. C is in the range of the creep strength for Incoloy 800. 29 figs

  11. Performance of aluminide coatings applied on alloy CF8C plus at 800 C

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Deepak [ORNL; Dryepondt, Sebastien N [ORNL; Shyam, Amit [ORNL; Haynes, James A [ORNL; Pint, Bruce A [ORNL; Armstrong, Beth L [ORNL; Lara-Curzio, Edgar [ORNL

    2011-01-01

    The cost effective, austenitic stainless steel CF8C plus is an attractive alloy for massive cast structures such as steam turbine casings. The microstructure stability and creep strength of this alloy are better than commercial high-performance heat-resistant steels such as NF709 and Super 304H, and are comparable to the Ni-based superalloy Inconel 617. The oxidation resistance of the alloy in atmosphere rich in water vapor is however insufficient at T>800 C, and the use of diffusion aluminide coatings is considered for potential high temperature applications. The thermal stability and protectiveness of coatings applied on the CF8C plus substrate by pack cementation and slurry process were investigated in air + 10% H2O environment at 800 C. Further, the coating effect on the fatigue life of the alloy was assessed via low-cycle-fatigue experiments.

  12. Effects of composition, heat treatment and cold work on structure and properties of alloy 800

    International Nuclear Information System (INIS)

    The creep characteristics of alloy 800 at temperatures around 6000C are greatly affected by the composition and treatments in the final stages of manufacture. Short-term and creep properties of alloy 800 at 6000C are described for six melts covering the carbon range 0.054-0.078%, the titanium range 0.23-0.57% and the aluminium range 0.17-0.52%. The properties are related to the alloy chemistry and the microstructure. It is shown that homogeneously nucleated γ'-precipitates are the main cause of low ductility in alloy 800 but there is also some influence of, for instance, grain boundary M23C6 films and discontinuous precipitation of Ni3Ti or M23C6 in grain boundaries. The extent of γ'-precipitation is controlled primarily by the (Ti+Al)-content. To avoid γ' and ensure a high creep ductility the (Ti+Al)-content should be limited to 0.70-0.75% for alloy 800 with a carbon content of 0.054-0.078% and solution annealed at 11500C. A lower solution temperature will reduce the matrix Ti-content and push the allowed total (Ti+Al)-content upwards. The effect of grain size is such that a coarse-grained material becomes more brittle than a fine-grained one. Cold work of up to 10% will enhance the creep-rupture strength but reduce the ductility

  13. Studies on the growth of oxide films on alloy 800 and alloy 600 in lithiated water at high temperature

    International Nuclear Information System (INIS)

    In this work, the oxide films grown on Alloy 800 and Alloy 600 in lithiated (pH25Cdegrees = 10.2-10.4) water at high temperature, with and without hydrogen overpressure (HO) and an initial oxygen dissolved in the water have been studied. The oxide films were grown at different temperatures (220-350 C degrees) and exposure times with HO, and at 315 C degrees without HO in static autoclaves. Some results are also reported for oxide layers grown on Alloy 800 coupons exposed in a high temperature loop during extended exposure times. The average oxide thickness was determined using descaling procedures. The morphology and composition of the oxide films were analyzed with scanning electron microscopy (SEM), EDS and X-ray diffraction (XRD). For both Alloys, at 350 C degrees with HO, the oxide layers were clearly composed of a double layer: an inner one of very small crystallites and an outer layer formed by bigger crystals scattered over the inner one. The analysis by X-ray diffraction indicated the presence of spinel structures like magnetite (Fe3O4) and ferrites and/or nickel chromites. In this case the average oxide thickness was around 0.12 to 0.15 μm for both Alloys. Similar values were found at lower temperatures. The morphology of the oxide layer was similar at lower temperatures for Alloy 800, but a different morphology consisting of platelets or needles was found for Alloy 600. The oxide morphology found at 315 C degrees, without HO and with initial dissolved oxygen in the water, was also very different between both Alloys. The oxide film grown on Alloy 600 with an initial dissolved oxygen in the water, showed clusters of platelets forming structures like flowers that were dispersed on an rather homogeneous layer consisting of smaller platelets or needles. The average oxide film grown in this case was around 0.25 μm for Alloy 600 and 0.18 μm for Alloy 800. (author)

  14. Testing of degradation of alloy 800 H in impure helium at 760 °C

    International Nuclear Information System (INIS)

    Highlights: • Exposure of base metal, weld metal and heat affected zone specimens of alloy 800 H in impure helium. • Test temperature: 760 °C. • Exposure time: up to 1500 h. • Post exposure tests: weight changes, SEM/EDX, optical microscope, ESCA, hardness, micro hardness. - Abstract: The base metal, weld metal and heat affected zone specimen of alloy 800 H were exposed to impure helium at 760 °C for up to 1500 h. Helium impurities included 100 vppm of H2, 500 vppm of CO and 100 vppm CH4. The weight gain of alloy 800 H specimens were found to be higher than those of ferritic and austenitic stainless steel tested in similar environment. On the surface, corrosion product layers contained Cr and also Ti or Mn and other oxides. In some cases spalling of these layers was observed. Under corrosive layers the C, O, Ti, Cr and Al rich formations were also found. The exposure had no significant effect to hardness and micro hardness of tested alloy

  15. Air oxidation of Cu-50Ni and Cu-70Ni alloys at 800

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The air oxidation of Cu-Ni alloys with 50% and 70% nickel (mole fraction) at 800℃ was studied. The kinetic curves for the oxidation of the two alloys are complex and deviate from the parabolic rate law. Typical double-layered scales are produced, which consist of a CuO outer layer and an inner layer containing a mixture of Cu2O and NiO with many pores. Cu-50Ni presents a small degree of internal oxidation of nickel, which is observed in many binary double-phase systems, but is quite rare in single phase systems.

  16. High strain rate behavior of alloy 800H at high temperatures

    Science.gov (United States)

    Shafiei, E.

    2016-05-01

    In this paper, a new model using linear estimation of strain hardening rate vs. stress, has been developed to predict dynamic behavior of alloy 800H at high temperatures. In order to prove the accuracy and competency of the presented model, Johnson-Cook model pertaining modeling of flow stress curves was used. Evaluation of mean error of flow stress at deformation temperatures from 850 °C to 1050 °C and at strain rates of 5 S-1 to 20 S-1 indicates that the predicted results are in a good agreement with experimentally measured ones. This analysis has been done for the stress-strain curves under hot working condition for alloy 800H. However, this model is not dependent on the type of material and can be extended for any similar conditions.

  17. Effect of thermal cycling on the alloy 800/2.25 Cr-1 Mo steel joint

    International Nuclear Information System (INIS)

    The critical part of the trimetallic transition joint (type 304 stainless steel/Alloy 800/2.25 Cr-1 Mo steel), the Alloy 800/2.25 Cr-1 Mo steel joint welded with Inconel 182, was subjected to thermal cycling between room temperature and 873 K. The thermal cycling test procedure used produces accelerated failures in transition joints similar to those observed in steam generators of operating power plants. On thermal cycling, precipitation at the weld/ferritic steel interface decreased on post-weld heat treatment. This precipitation increased with increased prior ageing and applied stress. The results of these tests indicated a considerable improvement in performance of the trimetallic transition joint compared to the direct (bimetallic) transition joint. (orig.)

  18. Time-dependent Creep Crack Growth Behavior of Alloy 617 at 800 .deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woogon; Kim, Minhwan; Kim, Yongwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Jaeyoung; Ekaputra, I. M. W. [Pukyong National Univ., Busan (Korea, Republic of)

    2014-05-15

    The VHTR components are designed to be used for a 60 year lifetime at a high temperature, the creep crack growth (CCG) behavior as well as creep behavior is very important for the design application due to creep damage during the long service life at elevated temperatures. Alloy 617 is a major candidate material for the IHX component. The design of the component, which will operate well into the creep range, will require a good understanding of creep crack growth deformation. Efforts are now being undertaken in the Generation IV program to provide data needed for the design and licensing of the nuclear plants, and with this goal in mind, to meet the needs of the conceptual designers of the VHTR system, 'Gen-IV Materials Handbook DB' is being established through an international collaboration program of several GIF (Gen-IV Forum) countries. CCG experimental data should be prepared to 'the Gen-IV Materials Handbook DB' website, because the CCG data for Alloy 617 are not available in the ASME design code. In this paper, experimental creep crack growth data were obtained through a series of CCG tests performed under different applied loads at 800 .deg. C. The CCG behavior was characterized in terms of the C{sup *} fracture mechanics parameter, and the CCGR equation for Alloy 617 was presented. Experimental CCG data of Alloy 617 were obtained from a series of creep crack growth tests under different applied loads at 800 .deg. C.

  19. Characterization of microstructure and corrosion properties of cold worked Alloy 800

    International Nuclear Information System (INIS)

    X-ray diffraction studies indicated that cold worked (∼50%) Alloy 800 was austenitic and transmission electron microscopy revealed the presence of a small volume fraction of hexagonal ε-martensite along with deformation bands, high dislocation density and primary TiN particle with a few dislocations within it. The passivity of cold worked alloy was very stable in H2SO4 solution but unstable in HCl solution at room temperature. The exposure of cold worked alloy in 673 K steam (initial pH of water was 10.1) for a period of 264 h showed almost nil corrosion rate. Scanning electron microscopy revealed a number of small oxide particles on the surface exposed in steam indicating initiation of oxide formation. Energy dispersive X-ray analyses of the surface containing small oxide particles indicated that the surface composition was similar to bulk composition of the alloy. X-ray photoelectron spectroscopy revealed that the alloy surface exposed in steam contained mixed oxides of iron and chromium as well as elemental form of iron, nickel and chromium

  20. Stress corrosion cracking of alloys 690, 800, and 600 in acid environments containing copper oxides

    International Nuclear Information System (INIS)

    Secondary side stress corrosion cracking (SCC) of steam generator (SG) tubes may be due to the formation of an acid environment in crevices, as demonstrated for several Belgian PWR plants. The susceptibility of alloys 600 and 800 in this type of environment, which had been partially evidenced by several laboratory works, has been confirmed by capsule tests performed at Laborelec, whereas the SCC resistance of alloy 690 always appeared excellent. Capsule tests have been recently conducted at 320 C with the same heats of tubings in the same acid solutions (cationic resins + magnetite + sodium silicate, with or without lead, and sodium sulfate + iron sulfate, with or without lead oxide) containing CuO and Cu2O. It appeared that the SCC resistance of the three alloys was generally reduced by the addition of copper oxides, at least when the cover gas did not contain hydrogen. The situation was particularly dramatic for the capsules made of alloy 690 tubing: most of them developed deep cracks, sometimes throughwall (the shortest time to failure being less than 50 h) whereas the same solutions without copper oxides had produced no cracking at all in alloy 690 capsules exposed during more than 2,000 h. Although the corrosion is reduced in presence of hydrazine or at lower concentration, copper oxides probably contribute significantly to the degradation of the tubes in alloy 600, at least in SG's forming acid sulfate crevice environments. This is also an issue for the new SG's, especially for those equipped with tubes in alloy 690 TT, particularly for the top of the tubesheet which is a critical deposit area since the high stresses and strains resulting from the expansion of the tube in the tubesheet lead to a risk of circumferential cracking at the transition

  1. Hydrogen Permeability of Incoloy 800H, Inconel 617, and Haynes 230 Alloys

    International Nuclear Information System (INIS)

    A potential issue in the design of the NGNP reactor and high-temperature components is the permeation of fission generated tritium and hydrogen product from downstream hydrogen generation through high-temperature components. Such permeation can result in the loss of fission-generated tritium to the environment and the potential contamination of the helium coolant by permeation of product hydrogen into the coolant system. The issue will be addressed in the engineering design phase, and requires knowledge of permeation characteristics of the candidate alloys. Of three potential candidates for high-temperature components of the NGNP reactor design, the hydrogen permeability has been documented well only for Incoloy 800H, but at relatively high partial pressures of hydrogen. Hydrogen permeability data have been published for Inconel 617, but only in two literature reports and for partial pressures of hydrogen greater than one atmosphere, far higher than anticipated in the NGNP reactor. The hydrogen permeability of Haynes 230 has not been published. To support engineering design of the NGNP reactor components, the hydrogen permeability of Inconel 617 and Haynes 230 were determined using a measurement system designed and fabricated at the Idaho National Laboratory. The performance of the system was validated using Incoloy 800H as reference material, for which the permeability has been published in several journal articles. The permeability of Incoloy 800H, Inconel 617 and Haynes 230 was measured in the temperature range 650 to 950 C and at hydrogen partial pressures of 10-3 and 10-2 atm, substantially lower pressures than used in the published reports. The measured hydrogen permeability of Incoloy 800H and Inconel 617 were in good agreement with published values obtained at higher partial pressures of hydrogen. The hydrogen permeability of Inconel 617 and Haynes 230 were similar, about 50% greater than for Incoloy 800H and with similar temperature dependence.

  2. Hydrogen Permeability of Incoloy 800H, Inconel 617, and Haynes 230 Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Pattrick Calderoni

    2010-07-01

    A potential issue in the design of the NGNP reactor and high-temperature components is the permeation of fission generated tritium and hydrogen product from downstream hydrogen generation through high-temperature components. Such permeation can result in the loss of fission-generated tritium to the environment and the potential contamination of the helium coolant by permeation of product hydrogen into the coolant system. The issue will be addressed in the engineering design phase, and requires knowledge of permeation characteristics of the candidate alloys. Of three potential candidates for high-temperature components of the NGNP reactor design, the hydrogen permeability has been documented well only for Incoloy 800H, but at relatively high partial pressures of hydrogen. Hydrogen permeability data have been published for Inconel 617, but only in two literature reports and for partial pressures of hydrogen greater than one atmosphere, far higher than anticipated in the NGNP reactor. The hydrogen permeability of Haynes 230 has not been published. To support engineering design of the NGNP reactor components, the hydrogen permeability of Inconel 617 and Haynes 230 were determined using a measurement system designed and fabricated at the Idaho National Laboratory. The performance of the system was validated using Incoloy 800H as reference material, for which the permeability has been published in several journal articles. The permeability of Incoloy 800H, Inconel 617 and Haynes 230 was measured in the temperature range 650 to 950 °C and at hydrogen partial pressures of 10-3 and 10-2 atm, substantially lower pressures than used in the published reports. The measured hydrogen permeability of Incoloy 800H and Inconel 617 were in good agreement with published values obtained at higher partial pressures of hydrogen. The hydrogen permeability of Inconel 617 and Haynes 230 were similar, about 50% greater than for Incoloy 800H and with similar temperature dependence.

  3. Gas accumulation at grain boundaries during 800 MeV proton irradiation of aluminium and aluminium-alloys

    International Nuclear Information System (INIS)

    Samples of pure aluminium (99.9999%) and commercial Al-2.7%Mg (AlMg3) and Al-1.1%Mg-0.5%Si (Al6061) alloys were irradiated with 800 MeV protons at the Los Alamos Meson Physics Facility (LAMPF) at a temperature between 40-1000C to a maximum dose of 0.2 dpa. Transmission electron microscopy (TEM) showed a complete absence of voids or bubbles in the grain interiors of the aluminium and the aluminium-alloys. Bubbles were clearly visible by TEM at grain boundaries in pure Al and the AlMg3 alloy; but bubbles were not visible in the Al6061 alloy. The bubble density in the AlMg3 alloy was considerably higher than in pure Al. The amount of gas accumulation at grain boundaries was found to depend on gas generation rate, alloying and cold-work microstructure. (orig.)

  4. Relationship between carburization and zero-applied-stress creep dilation in Alloy 800H and Hastelloy X

    International Nuclear Information System (INIS)

    Typical HTGR candidate alloys can carburize when exposed to simulated service environments. The carbon concentration gradients so formed give rise to internal stresses which could cause dilation. Studies performed with Hastelloy X and Alloy 800H showed that dilations of up to almost 1% can occur at 10000C when carbon pickup is high. Dilation was normally observed only when the carbon increase was >1000 μg/cm2 and ceased when diffusing carbon reached the center of the specimen. (Auth.)

  5. New creep resistant cast alloys with improved oxidation resistance in water vapor at 650-800°C

    Science.gov (United States)

    Dryepondt, Sebastien; Pint, Bruce; Maziasz, Philip

    2015-08-01

    Cast stainless steel CF8C-Plus (19wt.%Cr/12%Ni) has excellent creep properties, but limited oxidation resistance above 700ºC in environments containing H2O. One strategy to improve the alloy oxidation performance is to increase the Cr and Ni concentration. Two new alloys, with respectively 21wt%Cr-15wt%Ni and 22wt%Cr-17.5wt%Ni were therefore developed and their long-term oxidation behavior in humid air were compared with the oxidation behavior of five other cast alloys. At 650 and 700ºC, all the alloys formed internal Cr-rich nodules, and outer nodules or layers rich in Fe and Ni, but they grew a protective Cr-rich inner layer over time. At 750ºC, the lower alloyed steels such as CF8C-Plus showed large metal losses, but the two new alloys still exhibited a protective oxidation behavior. The 21Cr-15Ni alloy was severely oxidized in locations at 800ºC, but that was not the case for the 22Cr-17.5Ni alloy. Therefore, the two new modified alloys represent a potential operating temperature gain of respectively 50 and 100ºC in aggressive environments compared with the CF8C-Plus alloy.

  6. New creep resistant cast alloys with improved oxidation resistance in water vapor at 650-800ºC

    Directory of Open Access Journals (Sweden)

    Sebastien eDryepondt

    2015-08-01

    Full Text Available Cast stainless steel CF8C-Plus (19wt.%Cr/12%Ni has excellent creep properties, but limited oxidation resistance above 700ºC in environments containing H2O. One strategy to improve the alloy oxidation performance is to increase the Cr and Ni concentration. Two new alloys, with respectively 21wt%Cr-15wt%Ni and 22wt%Cr-17.5wt%Ni were therefore developed and their long-term oxidation behavior in humid air were compared with the oxidation behavior of five other cast alloys. At 650 and 700ºC, all the alloys formed internal Cr-rich nodules, and outer nodules or layers rich in Fe and Ni, but they grew a protective Cr-rich inner layer over time. At 750ºC, the lower alloyed steels such as CF8C-Plus showed large metal losses, but the two new alloys still exhibited a protective oxidation behavior. The 21Cr-15Ni alloy was severely oxidized in locations at 800ºC, but that was not the case for the 22Cr-17.5Ni alloy. Therefore, the two new modified alloys represent a potential operating temperature gain of respectively 50 and 100ºC in aggressive environments compared with the CF8C-Plus alloy.

  7. Microstructure and mechanical properties of medium energy (600-800 MeV) proton irradiated commercial aluminium alloys

    International Nuclear Information System (INIS)

    Commercial AlMg- and AlMgSi-alloys were irradiated with medium energy (600-800 MeV) protons to a nominal fluence of 3.2 x 1024 p/m2 which yields by calculation a displacement damage of 0.2 dpa and helium and hydrogen generation of 67 and 275 appm, respectively. Post-irradiation tensile testing revealed a very marked degree of irradiation-induced softening in the cold-worked AlMg-alloy as well as in the precipitation-hardened AlMgSi-alloy. The TEM examination of the irradiated specimens showed that neither the cold-work microstructure in the AlMg-alloy nor the G.P. zone type precipitates in the AlMgSi-alloy survive under the irradiation conditions used in the present experiment. Results of complimentary investigations (i.e., hardness measurements, optical microscopy and SEM-fractography) are also presented. (author)

  8. Hot Deformation Behavior of Alloy 800H at Intermediate Temperatures: Constitutive Models and Microstructure Analysis

    Science.gov (United States)

    Cao, Y.; Di, H. S.; Misra, R. D. K.; Zhang, Jiecen

    2014-12-01

    The hot deformation behavior of a Fe-Ni-Cr austenitic Alloy 800H was explored in the intermediate temperature range of 825-975 °C and strain rate range of 0.01-10 s-1. The study indicates that dynamic recrystallization (DRX) occurred at 875-975 °C for strain rates of 0.01-0.1 s-1 and adiabatic heating generated at high strain rates accelerated the DRX process. Based on the experimental data, the Johnson-Cook, modified Johnson-Cook, and Arrhenius-type constitutive models were established to predict the flow stress during hot deformation. A comparative study was made on the accuracy and effectiveness of the above three developed models. The microstructure analysis indicated that all the deformation structures exhibited elongated grains and evidence of some degree of DRX. The multiple DRX at 975 °C and 0.01 s-1 led to an increase in the intensity of {001} "cube" texture component and a significant reduction in the intensity of {011} "brass" component. Additionally, the average values of grain average misorientation and grain orientation spread for deformed microstructure were inversely proportional to the fraction of DRX.

  9. Mechanical properties testing of several 800 MeV proton irradiated BCC metals and alloys

    International Nuclear Information System (INIS)

    A spallation neutron source for the 600-MeV proton accelerator facility at the Swiss Institute for Nuclear Research (SIN) consists of a vertical cylinder filled with molten Pb-Bi. The proton beam enters the cylinder, passing upward through a window in contact with the Pb-Bi eutectic liquid. Investigations are underway at the 800-MeV proton accelerator at LAMPF to test the performance of candidate SIN window materials. Based on considerations of chemical compatibility with molten Pb-Bi, as well as radiation damage mechanisms, Fe, Ta, Fe-2.25Cr-1Mo, and Fe-12Cr-1Mo (Ht-9) were chosen as candidate materials. Sheet tensile samples were sealed inside capsules containing Pb-Bi and were proton-irradiated at LAMPF to two fluences, 4.8 and 54 x 1023 p/m2. The beam current was approximately equal to the 1 mA anticipated for the upgraded SIN accelerator. Yield and ultimate strengths increased upon irradiation in all materials, while the ductility decreased. The pure metals, Ta and Fe, exhibited the greatest radiation hardening and embrittlement. The HT-9 alloy showed the smallest changes in strength and ductility

  10. Comparative study of oxalic and malonic acid behaviour in the chemical cleaning of alloy 800 surfaces

    International Nuclear Information System (INIS)

    This work consisted, in a first stage, on a basic study of the dissolution mechanism of nickel ferrite in aqueous malonic acid. Powdered oxides (NixFe3-xO4) were synthesized by wet procedures and heated at 750 C degrees. These oxides were characterized by conventional methods and dissolved under different experimental conditions (pH, reagent concentration, temperature, etc.) in order to determine the dissolution rates. Optimal dissolution conditions were explored and compared to the corresponding oxalic acid ones. In a second stage, these conditions were applied to oxides grown on Alloy 800 coupons. Before oxidation, all coupons were ground polished and then were exposed to hydrothermal conditions (350 C degrees, pH25Cdegrees≅ 10.4 -LiOH-, 20-22 days) in static autoclaves. Finally, oxidized and unoxidized coupons were treated with chemical solutions containing oxalic or malonic acid at conditions optimized in the first stage. These results were also compared to those obtained on coupons exposed to a commercial formulation, APAC (Alkaline Permanganate Ammonium Citrate), as a reference. The results on coupon descaling using APMAL (AP + Malonic), APOX (AP + oxalic) and the comparison with APAC leads to conclude that malonic acid is a reagent whose chemical behavior is much better than oxalic acid and comparable to commercial formulations. (author)

  11. Experimental research on solidification structure of alloy 800H by linear electromagnetic stirring

    Institute of Scientific and Technical Information of China (English)

    Jiang En; Wang Engang; Deng Anyuan

    2014-01-01

    The solidification structures of al oy 800H fabricated with and without linear electromagnetic stirring (L-EMS) were investigated. The results show that the solidification structure of the alloy can be obviously affected by the forced convection in melt caused by L-EMS. The average size of equiaxed grains of the al oy with L-EMS decreases from 3.5 mm to 2.3 mm, and the ratio of equiaxed grain increases from 5% to 43%compared with that without L-EMS. The microstructure of the al oy without L-EMS is composed of fine equiaxed dendrites in the outermost layer and columnar dendrites in other areas, whereas that with L-EMS contains equiaxed dendrites, columnar dendrites and cross dendrites. In addition, the mechanism of dendrite fragment drift was proved by examining the composition change of the main al oying elements in the dendrite trunks at different solidification stage using an electron probe micro-analyzer (EPMA).

  12. The influence of Incoloy-800 alloy microstructure upon SCC behaviour in the medium of primary circuit of the steam generator

    International Nuclear Information System (INIS)

    Stress cracking corrosion (SCC) in steam generator tubing is one of the major degrading processes appearing from simultaneous mechanical stress and environmental chemical aggression. It can affect the Incoloy-800 tubing in both primary and secondary circuits. The objective of this work was the analysis of behaviour to SCC of the micro structurally modified Incoloy-800 alloy (the material of the steam generator tubing) in hydrogen environment. The microstructural modification of the alloy was achieved by heat treatment in the temperature range 400 deg.C - 800 deg.C, specific to the grain limit of carbide precipitation. Subsequently to heat treatment, occurrence of precipitated carbides is accompanied by occurrence of Cr depleted areas which results in alloy sensitizing. These areas were evidenced by means of potential-dynamical reactivation method. Heat treatment of the samples tested for corrosion is described as well as the intrinsic effect of hydrogen upon Incoloy-800 samples. Incipient intergranular and even intragranular cracks were observed in the stressed and heat treated samples. Occurrence of cracks after 72 h is explained as due to the cathodic polarisation which concentrates the reaction of hydrogen release on alloy in areas with film damages and maximal stresses. The content of absorbed H2 was calculated by means of the electric charge determined by coulometric method in which the samples electrolytically hydrogenated were anodically polarized. The degree of hydrogen embrittlement of samples was determined by comparing the content of hydrogen absorbed by hydrogenated thermo-mechanically treated samples with that of the hydrogen absorbed by heat treated unstressed hydrogenated samples and with the content of hydrogen absorbed in the samples for delivery. In conclusion, the microstructurally modified alloy by heat treatment at 700 deg.C for 1 hour (sensitized) is more susceptible to SCC in primary circuit in the presence of hydrogen while material

  13. Dynamic behavior and microstructural evolution during moderate to high strain rate hot deformation of a Fe-Ni-Cr alloy (alloy 800H)

    Science.gov (United States)

    Cao, Yu; Di, Hongshuang; Zhang, Jiecen; Yang, Yaohua

    2015-01-01

    The objective of the study is to fundamentally understand the dynamic behavior of alloy 800H at moderate to high strain rate using hot compression tests and propose nucleation mechanism associated with dynamic crystallization (DRX). We firstly investigated the dynamic behavior of alloy 800H with industrial scale strain rates using hot compression tests and adiabatic correction was performed to correct as-measured flow curves. Secondly, a Johnson-Cook model was established by using the corrected data and could give a precise prediction of elevated temperature flow stress for the studied alloy. Finally, the nucleation mechanism of DRX grains at high strain rates was studied. The results showed that the predominant nucleation mechanism for DRX is the formation of "bulge" at parent grain boundary. Additionally, the fragmentation of original grain at low deformation temperatures and the twinning near the bulged regions at high deformation temperatures also accelerate the DRX process.

  14. Dynamic behavior and microstructural evolution during moderate to high strain rate hot deformation of a Fe–Ni–Cr alloy (alloy 800H)

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Yu; Di, Hongshuang, E-mail: dhshuang@mail.neu.edu.cn; Zhang, Jiecen; Yang, Yaohua

    2015-01-15

    The objective of the study is to fundamentally understand the dynamic behavior of alloy 800H at moderate to high strain rate using hot compression tests and propose nucleation mechanism associated with dynamic crystallization (DRX). We firstly investigated the dynamic behavior of alloy 800H with industrial scale strain rates using hot compression tests and adiabatic correction was performed to correct as-measured flow curves. Secondly, a Johnson–Cook model was established by using the corrected data and could give a precise prediction of elevated temperature flow stress for the studied alloy. Finally, the nucleation mechanism of DRX grains at high strain rates was studied. The results showed that the predominant nucleation mechanism for DRX is the formation of “bulge” at parent grain boundary. Additionally, the fragmentation of original grain at low deformation temperatures and the twinning near the bulged regions at high deformation temperatures also accelerate the DRX process.

  15. Gas accumulation at grain boundaries during 800 MeV proton irradiation of aluminium and aluminium-alloys

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Horsewell, Andy; Sommer, W. F.;

    1986-01-01

    Samples of pure aluminium (99.9999%) and commercial Al-2.7%Mg(AlMg3) and Al-1.1%Mg-0.5%Si(Al6061) alloys were irradiated with 800 MeV protons at the Los Alamos Meson Physics Facility (LAMPF) at a temperature between 40-100°C to a maximum dose of 0.2 dpa. Transmission electron microscopy (TEM) sho...... higher than in the pure Al. The amount of gas accumulation at grain boundaries was found to depend on gas generation rate, alloying and cold-work microstructure...

  16. CYCLIC OXIDATION OF Ti-48%Al-2%Cr-2%Nb-(0~1%)W ALLOYS BETWEEN 800 AND 1000°C IN AIR

    OpenAIRE

    SANG-HWAN BAK; DONG YI SEO; SEON-JIN KIM; JAE CHUN LEE; DONG BOK LEE

    2010-01-01

    Ti-48%Al-2%Cr-2%Nb-(0, 0.5, 1) at.%W alloys were synthesized via the powder metallurgical route, and cyclically oxidized at 800, 900, or 1000°C in air for up to 100 h in order to find the effects of W on their oxidation characteristics. At 800°C, they oxidized relatively slowly, and the scales were thin and adherent. At 900°C, the scales began to spall locally. At 1000°C, they spalled repetitively during oxidation. Cr, Nb, and W improved the cyclic oxidation resistance of TiAl alloys. The oxi...

  17. Characterization of high temperature tensile and creep–fatigue properties of Alloy 800H for intermediate heat exchanger components of (V)HTRs

    Energy Technology Data Exchange (ETDEWEB)

    Kolluri, M., E-mail: kolluri@nrg.eu; Pierick, P. ten, E-mail: tenpierick@nrg.eu; Bakker, T., E-mail: t.bakker@nrg.eu

    2015-04-01

    Highlights: • High temperature tensile, creep–fatigue (C–F) properties of Alloy 800H are studied. • Strength and uniform elongation properties at 800 °C are much lower than RT values. • Strong influence of hold time and Δε{sub tot} on low cycle fatigue life was observed. • The total allowable C–F damage (D) at 800 °C decreases with the decreasing Δε{sub tot}. • Synergetic effect of C–F interactions showed stronger effect at lower Δε{sub tot} values. - Abstract: Alloy 800H is considered as a candidate material for intermediate heat exchanger (IHX) components of (very) high temperature reactors (V)HTRs. Qualification of the this alloy for the aforementioned nuclear applications requires understanding of its high temperature tensile, low-cycle fatigue behavior and creep–fatigue interactions because the IHX components suffer from combined creep–fatigue loadings resulting from thermally induced strain cycles associated with start-up and shutdown cycles. To this end, in this paper, the tensile properties of the Alloy 800H base and tungsten inert gas (TIG) welded materials are studied at three different temperatures, room temperature 21, 700 and 800 °C. Low cycle fatigue (LCF) behavior of the base material is investigated at 800 °C with no-hold time (no-HT) and hold time (HT) to study creep–fatigue interactions. The tensile test results showed substantial differences between the strength and ductility properties of the base and weld materials at all 3 temperatures, however, the trends in temperature dependence of tensile properties are similar for both base and weld materials. LCF studies with no-HT and HT showed a strong influence of HT on the low cycle fatigue life of this alloy illustrating the substantial influence of creep mechanisms at 800 °C. Finally, cumulative values of creep versus fatigue damage fractions are plotted in a creep–fatigue interaction diagram and these results are discussed with respect to the existing bi

  18. Characterization of high temperature tensile and creep–fatigue properties of Alloy 800H for intermediate heat exchanger components of (V)HTRs

    International Nuclear Information System (INIS)

    Highlights: • High temperature tensile, creep–fatigue (C–F) properties of Alloy 800H are studied. • Strength and uniform elongation properties at 800 °C are much lower than RT values. • Strong influence of hold time and Δεtot on low cycle fatigue life was observed. • The total allowable C–F damage (D) at 800 °C decreases with the decreasing Δεtot. • Synergetic effect of C–F interactions showed stronger effect at lower Δεtot values. - Abstract: Alloy 800H is considered as a candidate material for intermediate heat exchanger (IHX) components of (very) high temperature reactors (V)HTRs. Qualification of the this alloy for the aforementioned nuclear applications requires understanding of its high temperature tensile, low-cycle fatigue behavior and creep–fatigue interactions because the IHX components suffer from combined creep–fatigue loadings resulting from thermally induced strain cycles associated with start-up and shutdown cycles. To this end, in this paper, the tensile properties of the Alloy 800H base and tungsten inert gas (TIG) welded materials are studied at three different temperatures, room temperature 21, 700 and 800 °C. Low cycle fatigue (LCF) behavior of the base material is investigated at 800 °C with no-hold time (no-HT) and hold time (HT) to study creep–fatigue interactions. The tensile test results showed substantial differences between the strength and ductility properties of the base and weld materials at all 3 temperatures, however, the trends in temperature dependence of tensile properties are similar for both base and weld materials. LCF studies with no-HT and HT showed a strong influence of HT on the low cycle fatigue life of this alloy illustrating the substantial influence of creep mechanisms at 800 °C. Finally, cumulative values of creep versus fatigue damage fractions are plotted in a creep–fatigue interaction diagram and these results are discussed with respect to the existing bi-linear damage summation

  19. Temperature dependence of the dynamic fracture toughness of the alloy Incoloy 800 after cold work

    International Nuclear Information System (INIS)

    Instrumental impact tests were performed on prefatigued charpy-impact tests specimens of the material Incoloy 800 in the as-received state and after 5%, 10% and 25% cold work in the temperature range 293 ≤ T/K ≤ 1223. The impact energi es were determined with different methods, the agreement was excellent. The temperature dependence of the impact energies exhibit an intermediate maximum at 673 K (400deg C). This maximum is more or less suppressed with increasing cold work. The temperature dependence of the fracture toughness reveals a decrease with increasing temperature. The decrease is most pronounced in the as-received state. The isothermes of the impact energies as a function of cold work show that between the as-received state and 5% cold work a large decrease in the energy can be observed. This is very strongly pronounced at room temperature and at 673 K (400deg C). In this region the usual degree of cold work can be found manufacturing components. From this point of view of weakness of the material with respect to its mechanical properties can be expected. (orig.)

  20. 含锆Ti2AlNb基合金在800°C的高温氧化行为%Oxidation behavior of Zr-containing Ti2AlNb-based alloy at 800 °C

    Institute of Scientific and Technical Information of China (English)

    党薇; 李金山; 张铁邦; 寇宏超

    2015-01-01

    The oxidation behavior of Ti−22Al−(27−x)Nb−xZr (x=0, 1, 6) alloys at 800 °C for exposure time up to 100 h was examined. It is shown that oxidation rate of experimental alloys obeys the parabolic kinetics. Ti−22Al−26Nb−1Zr alloy demonstrates more excellent oxidation resistance than the other two alloys. The main oxidation products are TiO2, Al2O3 and AlNbO4 phases for all these alloys. For the Ti−22Al−26Nb−1Zr alloy, Zr addition can modify the growth mechanism of oxide scale, which can effectively hinder the diffusion of oxygen. Whereas, reaction of Zr with oxygen leads to the formation of ZrO2 precipitates for the Ti−22Al−21Nb−6Zr alloy, which promotes the oxygen ingress into the substrate. Meanwhile, oxidation affected zones, including internal-oxidation layer and oxygen-enriched zone, are present beneath the outmost oxide scale. The difference in these zones is derived from the phase constitution in the starting Ti−22Al−(27−x)Nb−xZr (x=0, 1, 6) alloys.%研究Ti−22Al−(27−x)Nb−xZr (x=0,1,6)合金在800°C暴露时间长达100 h条件下的氧化行为。结果表明,合金氧化速率符合抛物线规律。Ti−22Al−26Nb−1Zr 合金的氧化性能优于其他两种合金。这些合金的氧化产物主要有TiO2、Al2O3和AlNbO4。对于Ti−22Al−26Nb−1Zr合金,Zr的添加可以改善氧化层的生长过程,从而有效阻止氧的扩散。然而,对于Ti−22Al−21Nb−6Zr合金,Zr与氧发生反应,形成ZrO2,ZrO2促使氧向合金基体内部扩散。同时,在氧化层下,存在包括内氧化层和富氧层的氧影响区域。不同合金氧影响区的差异主要归因于合金的初始相结构。

  1. A pulsed eddy current probe for inspection of support plates from within Alloy-800 steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Krause, T. W.; Babbar, V. K.; Underhill, P. R. [Department of Physics, Royal Military College of Canada, Kingston, ON (Canada)

    2014-02-18

    Support plate degradation and fouling in nuclear steam generators (SGs) can lead to SG tube corrosion and loss of efficiency. Inspection and monitoring of these conditions can be integrated with preventive maintenance programs, thereby advancing station-life management processes. A prototype pulsed eddy current (PEC) probe, targeting inspection issues associated with SG tubes in SS410 tube support plate structures, has been developed using commercial finite element (FE) software. FE modeling was used to identify appropriate driver and pickup coil configurations for optimum sensitivity to changes in gap and offset for Alloy-800 SG tubes passing through 25 mm thick SS410 support plates. Experimental measurements using a probe that was manufactured based on the modeled configuration, were used to confirm the sensitivity of differential PEC signals to changes in relative position of the tube within the tube support plate holes. Models investigated the effect of shift and tilt of tube with respect to hole centers. Near hole centers and for small shifts, modeled signal amplitudes from the differentially connected coil pairs were observed to change linearly with tube shift. This was in agreement with experimentally measured TEC coil response. The work paves the way for development of a system targeting the inspection and evaluation of support plate structures in steam generators.

  2. A pulsed eddy current probe for inspection of support plates from within Alloy-800 steam generator tubes

    Science.gov (United States)

    Krause, T. W.; Babbar, V. K.; Underhill, P. R.

    2014-02-01

    Support plate degradation and fouling in nuclear steam generators (SGs) can lead to SG tube corrosion and loss of efficiency. Inspection and monitoring of these conditions can be integrated with preventive maintenance programs, thereby advancing station-life management processes. A prototype pulsed eddy current (PEC) probe, targeting inspection issues associated with SG tubes in SS410 tube support plate structures, has been developed using commercial finite element (FE) software. FE modeling was used to identify appropriate driver and pickup coil configurations for optimum sensitivity to changes in gap and offset for Alloy-800 SG tubes passing through 25 mm thick SS410 support plates. Experimental measurements using a probe that was manufactured based on the modeled configuration, were used to confirm the sensitivity of differential PEC signals to changes in relative position of the tube within the tube support plate holes. Models investigated the effect of shift and tilt of tube with respect to hole centers. Near hole centers and for small shifts, modeled signal amplitudes from the differentially connected coil pairs were observed to change linearly with tube shift. This was in agreement with experimentally measured TEC coil response. The work paves the way for development of a system targeting the inspection and evaluation of support plate structures in steam generators.

  3. The Deposition and removal of sub-micron particles of magnetite at the surface of alloy 800

    International Nuclear Information System (INIS)

    The rate of isothermal deposition of sub-micron particles of magnetite onto the surface of alloy 800 has been measured at pH between 4.2 and 9.3 at Re=10 000 and a fluid temperature of 25 degrees C. Deposition is modelled as a two-step process: transport of particles to the surface region followed by attachment to the surface. The deposition is limited by particle transport between pH 6.5 and 8.3, and by the rate of attachment for pH outside of that range. The rate of attachment has an Arrhenius dependence on surface temperature with an activation energy of 42 kJ/mole at pH 9.3. The rate of particle removal was negligible compared to the deposition rate, probably because the thickness of the viscous sub-layer was very much greater than the particle size. (author). 19 refs., 1 tab., 6 figs

  4. Effect of strain rate on the hydrogen plastification effect in VT20 titanium alloy in the temperature range of 500-800 C

    Energy Technology Data Exchange (ETDEWEB)

    Bashkin, I.O.; Poniatovskii, E.G.; Sen' kov, O.N.; Malyshev, V.IU. (Institut Fiziki Tverdogo Tela, Moscow (USSR))

    1990-02-01

    The plasticity characteristics of TB20-hydrogen alloys with 0, 0.40 and 0.58 percent (in volume) hydrogen content in the temperature range of 500-800 C and at the shear rate of 0.0001-1/s, are examined. The hydrogen addition to the TB20 alloy leads to a plasticity increase, especially appreciable at epsilon greater than or equal to 0.01/s in the temperature range of 600-720 C (20-45 times). With an increase in temperature and/or a decrease in the strain rate, the TB20 limit deformation increases monotonically, and the limit deformations of the TB20-hydrogen alloys pass through maxima. The alloy plasticity increase correlates with the appearance of softening and steady flow phases at the low stress level, with grain size reduction, and with an increase in deformation homogeneity. 18 refs.

  5. The effect of σ-phase precipitation at 800°C on the corrosion resistance in sea-water of a high alloyed duplex stainless steel

    OpenAIRE

    Wilms, M.E.; Gadgil, V.J.; Krougman, J.M.; IJsseling, F.P.

    1994-01-01

    Super-duplex stainless steels are recently developed high alloyed stainless steels that combine good mechanical properties with excellent corrosion resistance. Because of a high content of chromium and molybdenum, these alloys are susceptible to σ-phase precipitation during short exposure to temperatures between 650 and 950°C. The effect of 800°C aging on σ-phase formation and on the mechanical properties of a super-duplex stainless steel have been reported previously by the authors.1 This in...

  6. The impact of aging pre-treatment on the hot deformation behavior of alloy 800H at 750 °C

    International Nuclear Information System (INIS)

    The influence of aging pre-treatment on the hot deformation of a commercial alloy 800H was investigated through uniaxial compression tests. Aging pre-treatments were performed at 750 °C for 0 h, 5 h, 10 h, 20 h and 50 h, followed by compression tests at 750 °C with strain rates of 0.01 s−1, 0.1 s-1 and 1 s−1. The flow curves signified that the peak stress decreased evidently with increasing aging time. The microstructural analysis of alloy 800H after aging at 750 °C for 50 h indicated that the predominant precipitates are block-shaped Cr23C6 and cube-shaped Ti(C,N). The formation of grain-boundary Cr23C6 results in the segregation of Cr and C with the depletion of Ni at the grain boundaries. The kernel average misorientation maps after hot deformation demonstrates that the grain-boundary precipitates induce the pinning force to change the distribution of local misorientation and two different deformation patterns were defined to characterize the substructure developed near the grain boundaries

  7. Research on the hot deformation behavior of a Fe-Ni-Cr alloy (800H) at temperatures above 1000 °C

    Science.gov (United States)

    Cao, Yu; Di, Hongshuang

    2015-10-01

    Considering the pinning effect of fine carbides on grain boundaries, hot compression tests were performed above the dissolution temperature of Cr23C6 to investigate the hot deformation behavior of a Fe-Ni-Cr alloy (800H). The results show that the single peak stress associated with dynamic recrystalization (DRX) became more distinct at higher temperature and lower strain rate. The process of DRX was thoroughly stimulated when deformed above 1000 °C. Constitutive equations for hot deformation were established by regression analysis of conventional hyperbolic sine equation. The relationships between Zener-Hollomon parameter (Z) and the characteristic points of flow curves were established using the power law relation. Furthermore, kernel average misorientation (KAM) and grain orientation spread (GOS) were used to map the distribution of local misorientation and estimate the fraction of DRX, respectively. The critical strain and peak strain were used to predict the kinetics of DRX with the Avrami-type equation.

  8. The Dislocation Sub-structure Evolution during Hot Compressive Deformation of Ti-6Al-2Zr-1Mo-1V Alloy at 800

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; ZHU Jingchuan; WANG Yang; ZhAN Jiajun

    2009-01-01

    Hot compressive behaviors of Ti-6Al-2Zr-1Mo-1V alloy at 800 ℃, as well as the evolution of microstructure during deformation process, were investigated. The experimental results show that flow stress increases to a peak stress followed by a decease with increasing strain, and finally forms a stable stage. Dislocations are generated at the interface of α/β phase, and the phase interface and dislocation loops play an important role in impeding the movement of dislocation. As strain in-creasing, micro-deformation bands with high-density dislocation are formed, and dynamic recrystal-lizaton occurs finally. XRD Fourier analysis reveals that dislocation density increases followed by a decrease during compressive deformation, and falls into the range from 10~(10) to 10~(11)cm~(-2).

  9. Influence of high-temperature exposure on the microstructure and mechanical properties of dissimilar metal welds between modified 9Cr-1Mo steel and alloy 800

    Science.gov (United States)

    Sireesha, M.; Albert, Shaju K.; Sundaresan, S.

    2005-06-01

    Transition joints between ferritic steel and austenitic stainless steel are commonly encountered in high-temperature components of power plants. Service failures in these are known to occur as a result, mainly, of thermal stresses due to expansion coefficient differentials. In order to mitigate the problem, a trimetallic configuration involving an intermediate piece of a material such as Alloy 800 between the ferritic and austenitic steels has been suggested. In our work, modified 9Cr-1Mo steel and 316LN stainless steel are used as the ferritic and austenitic components and the thermal behavior of the joints between modified 9Cr-1Mo steel and Alloy 800 is described in this article. The joints, made using the nickel-base filler material INCONEL 82/182 (INCONEL 82 for the root pass by gas-tungsten arc welding and INCONEL 182 for the filler passes by shielded-metal arc welding), were aged at 625 °C for periods up to 5000 hours. The microstructural changes occurring in the weld metal as well as at the interfaces with the two parent materials are characterized in detail. Results of across-the-weld hardness surveys and cross-weld tension tests and weld metal Charpy impact tests are correlated with the structural changes observed. Principally, the results show that (1) the tendency for carbon to diffuse from the ferritic steel into the weld metal is much less pronounced than when 2.25Cr-1Mo steel is used as the ferritic part; and (2) intermetallic precipitation occurs in the weld metal for aging durations longer than 2000 hours, but the weld metal toughness still remains adequate in terms of the relevant specification.

  10. Oxidation of Slurry Aluminide Coatings on Cast Stainless Steel Alloy CF8C-Plus at 800oC in Water Vapor

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, James A [ORNL; Armstrong, Beth L [ORNL; Dryepondt, Sebastien N [ORNL; Kumar, Deepak [ORNL; Zhang, Ying [Tennessee Technological University

    2013-01-01

    A new, cast austenitic stainless steel, CF8C-Plus, has been developed for a wide range of high temperature applications, including diesel exhaust components, turbine casings and turbocharger housings. CF8C-Plus offers significant improvements in creep rupture life and creep rupture strength over standard CF8C steel. However, at higher temperatures and in more aggressive environments, such as those containing significant water vapor, an oxidation-resistant protective coating will be necessary. The oxidation behavior of alloys CF8C and CF8C-Plus with various aluminide coatings were compared at 800oC in air plus 10 vol% water vapor. Due to their affordability, slurry aluminides were the primary coating system of interest, although chemical vapor deposition (CVD) and pack cementation coatings were also compared. Additionally, a preliminary study of the low cycle fatigue behavior of aluminized CF8C-Plus was conducted at 800oC. Each type of coating provided substantial improvements in oxidation behavior, with simple slurry aluminides showing very good oxidation resistance after 4,000 h testing in water vapor. Preliminary low cycle fatigue results indicated that thicker aluminide coatings degraded high temperature fatigue properties of CF8C-Plus, whereas thinner coatings did not. Results suggest that appropriately designed slurry aluminide coatings are a viable option for economical, long-term oxidation protection of austenitic stainless steels in water vapor.

  11. Microstructural Evolution during Creep of Alloy 800HT in the Temperature Range 600 °C to 1000 °C

    Science.gov (United States)

    Erneman, J.; Nilsson, J.-O.; Andrén, H.-O.; Tobjörk, D.

    2009-03-01

    The microstructure of SANICRO 31HT (alloy 800HT) creep tested to a maximum of 85,388 hours in the temperature range of 600 °C to 1000 °C was investigated. Coarse Ti(C, N) precipitates were found to form in the melt and remained stable after solution annealing and aging at all temperatures investigated. M23C6 precipitating in the range of 600 °C to 700 °C was found in two different distributions: as intergranular precipitates and as small intragranular particles. The γ' precipitation sequence was followed at 600 °C, 650 °C, and 700 °C, and the volume fraction and precipitate diameter was assessed using energy-filtered transmission electron microscopy (EFTEM). The γ' precipitates grew and coarsened slowly at 600 °C (10 to 30 nm) but somewhat faster at 650 °C (25 to 50 nm). The volume fraction was largest at 600 °C. The γ' precipitates formed at 700 °C were not homogeneously distributed in the matrix. Instead, γ' was observed in the immediate vicinity of M23C6 and Ti(C, N) precipitates. Atom probe field ion microscope analysis of γ'-precipitate showed that it contained slightly more Ti than Al and that its Fe content was a few atomic percent. Nitrogen uptake was very pronounced in creep-deformed material aged at 1000 °C, and AlN formed as grain boundary needles and in the interior of grains.

  12. Effect of the surface oxidization and nitridation on the normal spectral emissivity of titanium alloys Ti-6Al-4V at 800-1100 K at a wavelength of 1.5 μm

    Science.gov (United States)

    Zhu, Wenjie; Shi, Deheng; Zhu, Zunlue; Sun, Jinfeng

    2016-05-01

    This work strived to model the effect of surface oxidization and nitridation on the normal spectral emissivity of Ti-6Al-4V alloys at a temperature range of 800-1100 K and a wavelength of 1.5 μm. In experiments, the detector was as close to perpendicular to the surface of the specimens as possible so that only the normal spectral emissivity was measured. Two thermocouples were symmetrically welded near the measuring area for accurate measuring and monitoring of the temperature at the surface of the specimen. The specimens were heated for 6 h at a certain temperature. During this period, the normal spectral emissivity values were measured once every 1 min during the initial 180 min, and once every 2 min thereafter. The measurements were made at certain temperatures from 800 to 1100 K in intervals of 20 K. One strong oscillation in the normal spectral emissivity was observed at each temperature. The oscillations were formed by the interference between the radiation stemming from the oxidization and nitridation layer on the specimen surface and radiation from the substrate. The uncertainty in the normal spectral emissivity caused only by the surface oxidization and nitridation was found to be approximately 9.5-22.8%, and the corresponding uncertainty in the temperature generated only by the surface oxidization and nitridation was approximately 6.9-15.5 K. The model can reproduce well the normal spectral emissivity, including the strong oscillation that occurred during the initial heating period.

  13. Influence of niobium additions on mechanical properties and corrosion of INCOLOY 800 H

    International Nuclear Information System (INIS)

    The studies were carried out with six model alloys of the type INCOLOY alloy 800 H (32 Ni/20 Cr), obtained by variation of the niobium additions with up to 1.55 wt. p.c. of Nb. The mechanical properties and structural characteristics of these samples are listed after treatments as follows: - Aging at 650, 800, and 9000C (Notch bending tests and tensile tests at room temperature). - Carbonisation at 800 and 9000C in PNP standard helium (C-analysis, long-term creep tests at 9000C). Alloys with Nb additions showed constant good strength and ductility after aging, values being better than those for material without Nb additions. The creep tests showed that tensile strengths is improved with increasing niobium content; carbonisation is less than in alloys without Nb. (orig./IHOE)

  14. 7 CFR 800.2 - Administrator.

    Science.gov (United States)

    2010-01-01

    ... appear at part 68 of this title (7 CFR part 68). The Administrator is authorized by the Secretary to take... 7 Agriculture 7 2010-01-01 2010-01-01 false Administrator. 800.2 Section 800.2 Agriculture... § 800.2 Administrator. The Administrator is delegated, from the Secretary, responsibility...

  15. 7 CFR 800.198 - Contracts.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Contracts. 800.198 Section 800.198 Agriculture..., Designations, Approvals, Contracts, and Conflicts of Interest § 800.198 Contracts. (a) Services contracted and who may apply. The Service may enter into a contract with any person, State, or governmental agency...

  16. 31 CFR 800.509 - Materiality.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Materiality. 800.509 Section 800.509 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF INVESTMENT... FOREIGN PERSONS Committee Procedures: Review and Investigation § 800.509 Materiality. The...

  17. 20 CFR 638.800 - Program management.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Program management. 638.800 Section 638.800... TITLE IV-B OF THE JOB TRAINING PARTNERSHIP ACT Administrative Provisions § 638.800 Program management. (a) The Job Corps Director shall establish and use internal program management procedures...

  18. 10 CFR 800.002 - Program management.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Program management. 800.002 Section 800.002 Energy DEPARTMENT OF ENERGY LOANS FOR BID OR PROPOSAL PREPARATION BY MINORITY BUSINESS ENTERPRISES SEEKING DOE CONTRACTS AND ASSISTANCE General § 800.002 Program management. Program management responsibility...

  19. 31 CFR 800.225 - United States.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 800.225 Section 800... TAKEOVERS BY FOREIGN PERSONS Definitions § 800.225 United States. The term United States or U.S. means the United States of America, the States of the United States, the District of Columbia, and any...

  20. 46 CFR 177.800 - General requirements.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false General requirements. 177.800 Section 177.800 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) CONSTRUCTION AND ARRANGEMENT Passenger Accommodations § 177.800 General requirements. (a) All...

  1. 31 CFR 800.228 - Voting interest.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Voting interest. 800.228 Section 800... TAKEOVERS BY FOREIGN PERSONS Definitions § 800.228 Voting interest. The term voting interest means any interest in an entity that entitles the owner or holder of that interest to vote for the election...

  2. 31 CFR 800.101 - Scope.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Scope. 800.101 Section 800.101 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF INVESTMENT... FOREIGN PERSONS General § 800.101 Scope. The regulations in this part implement section 721 of title...

  3. 31 CFR 800.221 - Person.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Person. 800.221 Section 800.221 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF INVESTMENT... FOREIGN PERSONS Definitions § 800.221 Person. The term person means any individual or entity....

  4. 7 CFR 800.15 - Services.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Services. 800.15 Section 800.15 Agriculture... ADMINISTRATION (FEDERAL GRAIN INSPECTION SERVICE), DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS Official Inspection and Class X Or Class Y Weighing Requirements § 800.15 Services. (a) General. These...

  5. 31 CFR 800.215 - Foreign national.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Foreign national. 800.215 Section 800.215 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... TAKEOVERS BY FOREIGN PERSONS Definitions § 800.215 Foreign national. The term foreign national means...

  6. 31 CFR 800.216 - Foreign person.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Foreign person. 800.216 Section 800... TAKEOVERS BY FOREIGN PERSONS Definitions § 800.216 Foreign person. The term foreign person means: (a) Any foreign national, foreign government, or foreign entity; or (b) Any entity over which control is...

  7. 31 CFR 800.201 - Business day.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Business day. 800.201 Section 800.201 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF INVESTMENT... FOREIGN PERSONS Definitions § 800.201 Business day. The term business day means Monday through...

  8. 14 CFR 1212.800 - Civil remedies.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Civil remedies. 1212.800 Section 1212.800... Comply With Requirements of This Part § 1212.800 Civil remedies. Failure to comply with the requirements of the Privacy Act and this part could subject NASA to civil suit under the provisions of 5...

  9. Investigation of joining techniques for advanced austenitic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Lundin, C.D.; Qiao, C.Y.P.; Kikuchi, Y.; Shi, C.; Gill, T.P.S.

    1991-05-01

    Modified Alloys 316 and 800H, designed for high temperature service, have been developed at Oak Ridge National Laboratory. Assessment of the weldability of the advanced austenitic alloys has been conducted at the University of Tennessee. Four aspects of weldability of the advanced austenitic alloys were included in the investigation.

  10. Tritium Permeability of Incoloy 800H and Inconel 617

    Energy Technology Data Exchange (ETDEWEB)

    Philip Winston; Pattrick Calderoni; Paul Humrickhouse

    2012-07-01

    Design of the Next Generation Nuclear Plant (NGNP) reactor and its high-temperature components requires information regarding the permeation of fission generated tritium and hydrogen product through candidate heat exchanger alloys. Release of fission-generated tritium to the environment and the potential contamination of the helium coolant by permeation of product hydrogen into the coolant system represent safety basis and product contamination issues. Of the three potential candidates for high-temperature components of the NGNP reactor design, only permeability for Incoloy 800H has been well documented. Hydrogen permeability data have been published for Inconel 617, but only in two literature reports and for partial pressures of hydrogen greater than one atmosphere, far higher than anticipated in the NGNP reactor. To support engineering design of the NGNP reactor components, the tritium permeability of Inconel 617 and Incoloy 800H was determined using a measurement system designed and fabricated at Idaho National Laboratory. The tritium permeability of Incoloy 800H and Inconel 617, was measured in the temperature range 650 to 950°C and at primary concentrations of 1.5 to 6 parts per million volume tritium in helium. (partial pressures of 10-6 atm)—three orders of magnitude lower partial pressures than used in the hydrogen permeation testing. The measured tritium permeability of Incoloy 800H and Inconel 617 deviated substantially from the values measured for hydrogen. This may be due to instrument offset, system absorption, presence of competing quantities of hydrogen, surface oxides, or other phenomena. Due to the challenge of determining the chemical composition of a mixture with such a low hydrogen isotope concentration, no categorical explanation of this offset has been developed.

  11. Tritium Permeability of Incoloy 800H and Inconel 617

    Energy Technology Data Exchange (ETDEWEB)

    Philip Winston; Pattrick Calderoni; Paul Humrickhouse

    2011-09-01

    Design of the Next Generation Nuclear Plant (NGNP) reactor and its high-temperature components requires information regarding the permeation of fission generated tritium and hydrogen product through candidate heat exchanger alloys. Release of fission-generated tritium to the environment and the potential contamination of the helium coolant by permeation of product hydrogen into the coolant system represent safety basis and product contamination issues. Of the three potential candidates for high-temperature components of the NGNP reactor design, only permeability for Incoloy 800H has been well documented. Hydrogen permeability data have been published for Inconel 617, but only in two literature reports and for partial pressures of hydrogen greater than one atmosphere, far higher than anticipated in the NGNP reactor. To support engineering design of the NGNP reactor components, the tritium permeability of Inconel 617 and Incoloy 800H was determined using a measurement system designed and fabricated at Idaho National Laboratory. The tritium permeability of Incoloy 800H and Inconel 617, was measured in the temperature range 650 to 950 C and at primary concentrations of 1.5 to 6 parts per million volume tritium in helium. (partial pressures of 10-6 atm) - three orders of magnitude lower partial pressures than used in the hydrogen permeation testing. The measured tritium permeability of Incoloy 800H and Inconel 617 deviated substantially from the values measured for hydrogen. This may be due to instrument offset, system absorption, presence of competing quantities of hydrogen, surface oxides, or other phenomena. Due to the challenge of determining the chemical composition of a mixture with such a low hydrogen isotope concentration, no categorical explanation of this offset has been developed.

  12. Tantalum modified ferritic iron base alloys

    Science.gov (United States)

    Oldrieve, R. E.; Blankenship, C. P. (Inventor)

    1977-01-01

    Strong ferritic alloys of the Fe-CR-Al type containing 0.4% to 2% tantalum were developed. These alloys have improved fabricability without sacrificing high temperature strength and oxidation resistance in the 800 C (1475 F) to 1040 C (1900 F) range.

  13. 34 CFR 300.800 - In general.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false In general. 300.800 Section 300.800 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN...

  14. 31 CFR 800.303 - Lending transactions.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Lending transactions. 800.303 Section... TAKEOVERS BY FOREIGN PERSONS Coverage § 800.303 Lending transactions. (a) The extension of a loan or a... whether the foreign person has made any arrangements to transfer management decisions and...

  15. 31 CFR 800.211 - Entity.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Entity. 800.211 Section 800.211 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF INVESTMENT... separate legal entity) operated by any one of the foregoing as a business undertaking in a...

  16. 31 CFR 800.207 - Covered transaction.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Covered transaction. 800.207 Section 800.207 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF..., which could result in control of a U.S. business by a foreign person....

  17. 31 CFR 800.212 - Foreign entity.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Foreign entity. 800.212 Section 800.212 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... business is outside the United States or its equity securities are primarily traded on one or more...

  18. 31 CFR 800.209 - Critical technologies.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Critical technologies. 800.209..., AND TAKEOVERS BY FOREIGN PERSONS Definitions § 800.209 Critical technologies. The term critical technologies means: (a) Defense articles or defense services covered by the United States Munitions List...

  19. A Special TMCP Used to Develop a 800MPa Grade HSLA Steel

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effect of relaxation after finished rolling on structure s and properties of four microalloyed steel with different content of Nb and Ti was investigated. By alloy designing and control rolling+rel axation-precipitation-control phase transformation (RPC) process, a ne w 800MPa grade HSLA plate steel could be obtained, the microstructure is composite ultra-fine lath bainite/martensite. The tempering process and mechanical properties of this kind of HSLA steel were investigate d. The yield strength can achieve 800MPa, and the ductility and impact toughness is satisfied.

  20. Oxidation characteristics of Beta-21S in air in the temperature range 600 to 800 C

    Science.gov (United States)

    Wallace, Terryl A.; Clark, Ronald K.; Wiedemann, Karl E.

    1992-01-01

    The metastable beta-Ti alloy Beta-21S, Ti-15Mo-2.7Nb-3Al-0.2Si (weight percent), has been proposed as a candidate for use in metal matrix composites in future hypersonic vehicles. The present study investigated the oxidation behavior of Beta-21S over the temperature range 600 C to 800 C. Oxidation weight gain was evaluated using thermogravimetric analysis. Oxidized specimens were evaluated using x ray diffraction techniques, scanning electron microscopy, energy dispersive x ray analysis, and electron microprobe analysis to identify oxidation products and evaluate oxidation damage to the alloy.

  1. Cascaded quadratic soliton compression at 800 nm

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Moses, Jeffrey;

    2007-01-01

    We study soliton compression in quadratic nonlinear materials at 800 nm, where group-velocity mismatch dominates. We develop a nonlocal theory showing that efficient compression depends strongly on characteristic nonlocal time scales related to pulse dispersion.......We study soliton compression in quadratic nonlinear materials at 800 nm, where group-velocity mismatch dominates. We develop a nonlocal theory showing that efficient compression depends strongly on characteristic nonlocal time scales related to pulse dispersion....

  2. Status of Testing and Characterization of CMS Alloy 617 and Alloy 230

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Weiju [ORNL; Santella, Michael L [ORNL; Battiste, Rick [ORNL; Terry, Totemeier [Idaho National Laboratory (INL); Denis, Clark [Idaho National Laboratory (INL)

    2006-08-01

    Status and progress in testing and characterizing CMS Alloy 617 and Alloy 230 tasks in FY06 at ORNL and INL are described. ORNL research has focused on CMS Alloy 617 development and creep and tensile properties of both alloys. In addition to refurbishing facilities to conduct tests, a significant amount of creep and tensile data on Alloy 230, worth several years of research funds and time, has been located and collected from private enterprise. INL research has focused on the creep-fatigue behavior of standard chemistry Alloy 617 base metal and fusion weldments. Creep-fatigue tests have been performed in air, vacuum, and purified Ar environments at 800 and 1000 C. Initial characterization and high-temperature joining work has also been performed on Alloy 230 and CCA Alloy 617 in preparation for creep-fatigue testing.

  3. 48 CFR 19.800 - General.

    Science.gov (United States)

    2010-10-01

    ... Business Administration (SBA) to enter into all types of contracts with other agencies and let subcontracts... BUSINESS PROGRAMS Contracting With the Small Business Administration (the 8(a) Program) 19.800 General. (a... program as the 8(a) Business Development (BD) Program. (e) Before deciding to set aside an acquisition...

  4. 14 CFR 1214.800 - Scope.

    Science.gov (United States)

    2010-01-01

    ... Services § 1214.800 Scope. This subpart 1214.8 establishes the special reimbursement policy for Spacelab services provided to Space Transportation System (STS) customers governed by the provisions of subpart 1214... . (d) Complete-pallet flight . (e) Shared-element flight ....

  5. 28 CFR 800.5 - Agency components.

    Science.gov (United States)

    2010-07-01

    ... Services. (11) Office of Management and Administration. (12) Office of Human Resources. (b) PSA. (1) Office... Drug Testing Laboratory). (5) Human Resources Management. (6) Finance and Administration. ... ORGANIZATION AND FUNCTIONS § 800.5 Agency components. (a) CSOSA. (1) Office of the Director (including...

  6. 48 CFR 1319.800 - General.

    Science.gov (United States)

    2010-10-01

    ... BUSINESS PROGRAMS Contracting With the Small Business Administration (the 8(a) Program) 1319.800 General. (a) By Partnership Agreement between the Small Business Administration (SBA) and the Department of... a class FAR deviation to applicable portions of FAR Subpart 19.8 and FAR Part 52. Under the...

  7. 7 CFR 800.87 - New inspections.

    Science.gov (United States)

    2010-01-01

    ... Methods and Procedures § 800.87 New inspections. (a) Identity lost. An applicant may request official... carrier or container, if the identity of the lot or the carrier or container has been lost. (b) Identity not lost. If the identity of the grain or the carrier or container is not lost, a new...

  8. Physiological correlates to 800 meter running performance.

    Science.gov (United States)

    Deason, J; Powers, S K; Lawler, J; Ayers, D; Stuart, M K

    1991-12-01

    Much of the previous research efforts aimed at determining those physiological characteristics that contribute to distance running success have centered around distances greater than 1500 meters with little attention to events such as the 800 meter run. Therefore, this investigation examined the relationship between selected physiological and body composition, characteristics and performance in an 800 meter run. Measurements of body composition, VO2max, running economy, and performance times for 100 and 300 meter dashes were obtained on 11 male track athletes. Stepwise multiple regression analysis was performed using 800 meter race time as the dependent variable. Although the combination of 300 and 100 meter run times, percent body fat, running economy and VO2 max as independent variables accounted for the greatest amount of total variance (r2 = .89), the additional variance explained by the model did not increase significantly (p greater than 0.05), when VO2max, percent body fat, and running economy were added to a model which contained 300 and 100 meter run time (r2 = .85) as the explanatory variables. These data offer additional support for the notion that much of the intramuscular ATP produce and utilized during an 800 meter run comes from anaerobic metabolic pathway. PMID:1806725

  9. MODELLING AND CHARACTERIZATION OF LASER WELDED INCOLOY 800 HT JOINTS

    Directory of Open Access Journals (Sweden)

    Sathiya Paulraj

    2016-06-01

    Full Text Available This study aims at finding the effect of laser welding speed on incoloy 800 HT. This alloy is one of the potential materials for Generation IV nuclear plants. Laser welding has several advantages over arc welding such as low fusion zone, low heat input and concentrated heat intensity. Three different welding speeds were chosen and CO2 laser welding was performed. 2D modeling and simulation were done using ANSYS 15 to find out the temperature distribution at different welding speeds and it was found that an increase in the welding speed decreased the temperature. Mechanical properties such as tensile strength, toughness and hardness were evaluated. The effect of welding speed on metallurgical characteristics was studied using optical microscopy (OM, Scanning Electron Microscopy (SEM with EDS, X-Ray Diffraction (XRD technique and fractographic analysis. From the results it was found that high welding speed (1400 mm/min decreased the joint strength. The M23C6 and Ni3Ti carbides were formed in a discrete chain and in a globular form along the grain boundaries of the weld region which increased the strength of the grain boundaries. Fractographic evaluations of the tested specimens for welding speed (1000 and 1200 mm/min showed deep and wide dimples indicating ductile failures.

  10. Perfect 800 Advanced Strategies for Top Students

    CERN Document Server

    Celenti, Dan

    2010-01-01

    Getting into the nation's most competitive universities requires more than a good SAT score, it requires a perfect score. Perfect 800: SAT Math gives advanced students the tools needed to master the SAT math test. Covering areas including arithmetic concepts; algebra; geometry; and additional topics such as probability and weighted average, the book offers exposure to a wide range of degrees of difficulty in a holistic approach that allows students to experience the "real thing," including the impact of time constraints on their performance. By emphasizing critical thinking and analytic skills

  11. Columbia Glacier in 1986; 800 meters retreat

    Science.gov (United States)

    Krimmel, R.M.

    1987-01-01

    Columbia Glacier, in Prince William Sound, Alaska, continued its rapid retreat in 1986, with a retreat of 800 m. Average velocity of the lower portion of the glacier, 10 September 1986 to 26 January 1987, was three km/yr, or about one-half of the velocity during similar periods for the previous three years. This reduced velocity is a new development in the progression of the retreat, and if the calving rate follows the pattern of previous years, will result in continued retreat. (Author 's abstract)

  12. 7 CFR 800.138 - Conflict of interest.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Conflict of interest. 800.138 Section 800.138 Agriculture Regulations of the Department of Agriculture (Continued) GRAIN INSPECTION, PACKERS AND STOCKYARD... Inspection Services § 800.138 Conflict of interest. Official personnel cannot perform or participate...

  13. 7 CFR 800.199 - Conflict-of-interest provisions.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Conflict-of-interest provisions. 800.199 Section 800... Delegations, Designations, Approvals, Contracts, and Conflicts of Interest § 800.199 Conflict-of-interest...) Prohibited conflicts of interest. Unless waived on a case-by-case basis by the Administrator under section...

  14. 7 CFR 800.217 - Equipment that shall be tested.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Equipment that shall be tested. 800.217 Section 800... Supervision, Monitoring, and Equipment Testing § 800.217 Equipment that shall be tested. (a) General. Testing... for which official performance requirements have been established shall be tested for accuracy....

  15. 25 CFR 170.800 - Who owns IRR transportation facilities?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Who owns IRR transportation facilities? 170.800 Section 170.800 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM BIA Road Maintenance § 170.800 Who owns IRR transportation facilities? Public...

  16. 25 CFR 11.800 - Jurisdiction of appellate division.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Jurisdiction of appellate division. 11.800 Section 11.800... LAW AND ORDER CODE Appellate Proceedings § 11.800 Jurisdiction of appellate division. The jurisdiction of the appellate division shall extend to all appeals from final orders and judgments of the...

  17. 48 CFR 2904.800-70 - Contents of contract files.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Contents of contract files. 2904.800-70 Section 2904.800-70 Federal Acquisition Regulations System DEPARTMENT OF LABOR GENERAL ADMINISTRATIVE MATTERS Government Contract Files 2904.800-70 Contents of contract files. (a) The reports...

  18. 48 CFR 4.800 - Scope of subpart.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Scope of subpart. 4.800 Section 4.800 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL ADMINISTRATIVE MATTERS Government Contract Files 4.800 Scope of subpart. This subpart prescribes requirements...

  19. 31 CFR 800.104 - Transactions or devices for avoidance.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Transactions or devices for avoidance. 800.104 Section 800.104 Money and Finance: Treasury Regulations Relating to Money and Finance..., ACQUISITIONS, AND TAKEOVERS BY FOREIGN PERSONS General § 800.104 Transactions or devices for avoidance....

  20. 7 CFR 800.88 - Loss of identity.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Loss of identity. 800.88 Section 800.88 Agriculture... Methods and Procedures § 800.88 Loss of identity. (a) Lots. Except as noted in paragraph (d) of this... personnel performing a reinspection, appeal inspection, or Board appeal inspection service, the identity...

  1. 7 CFR 800.98 - Weighing grain in combined lots.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Weighing grain in combined lots. 800.98 Section 800.98... Provisions and Procedures § 800.98 Weighing grain in combined lots. (a) General. The weighing of bulk or sacked grain loaded aboard, or being loaded aboard, or unloaded from two or more carriers as a...

  2. 30 CFR 75.800-2 - Approved circuit schemes.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved circuit schemes. 75.800-2 Section 75... § 75.800-2 Approved circuit schemes. The following circuit schemes will be regarded as providing the necessary protection to the circuits required by § 75.800: (a) Ground check relays may be used...

  3. 8 CFR 204.308 - Where to file Form I-800A or Form I-800.

    Science.gov (United States)

    2010-01-01

    ... provisionally approved under 8 CFR 204.313(g) and the petitioner has either adopted or obtained custody of the child for purposes of emigration and adoption, the Department of State officer with jurisdiction to... eligible both under 8 CFR 204.309(b)(4) for approval of a Form I-800 and under 8 CFR part 245...

  4. The new 800mm reflecting telescope

    Science.gov (United States)

    Teske, Hans-Joachim

    The design and capabilities of the 800-mm Ritchey-Chretien system are described. The optical system of the telescope has an aperture ratio of 1:8; is suitable for photography in a 1.5 deg field with photoplates of 16 x 16 cm; and consists of primary and secondary hyperbolically deformed mirrors. The attachment of the mirrors, position rotator, and offset guider to the tube, which is a truss structure, is examined. The mount for the telescope is an equatorial fork type. The electronic control system is a 16-bit microcomputer system; the functions of the control system are discussed. The 8-m polyester dome of the telescope consists of a supporting steel structure carrying shell elements of glass fiber-reinforced polyester resins. Consideration is given to the auxiliary devices of the telescope.

  5. Phase Equilibria in System Pd-Au-Sn and Pd-Cu-Sn at 800℃ and 500℃

    Institute of Scientific and Technical Information of China (English)

    KABANOVA E. G.; KAREVA M. A.; KUZNETSOV V. N.; VASEKIN V. V.

    2012-01-01

    Alloys of Pd-Au-Sn and Pd-Cu-Sn systems were investigated using metallography,electron microprobe,X-ray diff action and DTA.Partial isothermal sections were plots at 800℃ and 500℃.Ternary τ-phase having tetragonal structure has been established in each systems.The region of existence of phases in equilibrium with the solid solution based on palladium.

  6. The influence of surface condition on the metal dusting behavior of cast and wrought chromia forming alloys

    NARCIS (Netherlands)

    Hermse, C.G.M.; Asteman, H.; Ijzerman, R.M.; Jakobi, D.

    2013-01-01

    The current work investigated the impact of surface condition on the metal dusting behavior of chromia forming alloys. Five commercial alloys were included in the study, wrought 800H, 353MA, and cast G4859, G4852 Micro, and ET45 Micro, these alloys have a chromium and nickel content in the range of

  7. Pitting of steam-generator tubing alloys in solutions containing thiosulfate and sulfate or chloride.

    Science.gov (United States)

    Zhang, William; Carcea, Anatolie G; Newman, Roger C

    2015-01-01

    The pitting of nuclear steam generator tubing alloys 600, 690 and 800 was studied at 60 °C using dilute thiosulfate solutions containing excess sulfate or (for Alloy 600) chloride. A potentiostatic scratch method was used. In sulfate solutions, all alloys pitted at low potentials, reflecting their lack of protective Mo. The alloys demonstrated the most severe pitting at a sulfate : thiosulfate concentration ratio of ∼40. Alloy 600 pitted worst at a chloride : thiosulfate ratio of ∼2000. The results are interpreted through the mutual electromigration of differently charged anions into a pit nucleus, and differences in the major alloy component. PMID:25898311

  8. Texas Instruments /TI/ 800 x 800 charge-coupled device /CCD/ image sensor

    Science.gov (United States)

    Blouke, M. M.; Hall, J. E.; Cowens, M. W.; Janesick, J. R.

    1981-01-01

    Very-large area high-performance CCD image sensors with 800 x 800 pixel format have been successfully fabricated and operated on the basis of a three-level polysilicon gate technology. They are thinned to 8 microns over the entire 12.2 x 12.2 mm active area, and are used in the rear illumination mode. The light transfer characteristic has a gamma value of 1.000 + or - 0.002 over most of the dynamic range. Analysis of the noise behavior shows that the device SNR is shot-noise-limited over most of the dynamic range. Simple on-chip signal processing can be performed using an integration well to noiselessly collect signal charge from multiple pixels prior to reading out the charge. A UV-sensitive phosphor has been applied to the chip, yielding a device capable of imaging at wavelengths from the vacuum UV to the near IR.

  9. The Effect of Post-Bond Heat Treatment on Tensile Property of Diffusion Bonded Austenitic Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sunghoon; Kim, Sung Kwan; Jang, Changheui [KAIST, Daejeon (Korea, Republic of); Sah, Injin [KAERI, Daejeon (Korea, Republic of)

    2015-12-15

    Diffusion bonding is the key manufacturing process for the micro-channel type heat exchangers. In this study, austenitic alloys such as Alloy 800HT, Alloy 690, and Alloy 600, were diffusion bonded at various temperatures and the tensile properties were measured up to 650 ℃. Tensile ductility of diffusion bonded Alloy 800HT was significantly lower than that of base metal at all test temperatures. While, for Alloy 690 and Alloy 600, tensile ductility of diffusion bonded specimens was comparable to that of base metals up to 500 ℃, above which the ductility became lower. The poor ductility of diffusion bonded specimen could have caused by the incomplete grain boundary migration and precipitates along the bond-line. Application of post-bond heat treatment (PBHT) improved the ductility close to that of base metals up to 550 ℃. Changes in tensile properties were discussed in view of the microstructure in the diffusionbonded area.

  10. NSC 800, 8-bit CMOS microprocessor

    Science.gov (United States)

    Suszko, S. F.

    1984-01-01

    The NSC 800 is an 8-bit CMOS microprocessor manufactured by National Semiconductor Corp., Santa Clara, California. The 8-bit microprocessor chip with 40-pad pin-terminals has eight address buffers (A8-A15), eight data address -- I/O buffers (AD(sub 0)-AD(sub 7)), six interrupt controls and sixteen timing controls with a chip clock generator and an 8-bit dynamic RAM refresh circuit. The 22 internal registers have the capability of addressing 64K bytes of memory and 256 I/O devices. The chip is fabricated on N-type (100) silicon using self-aligned polysilicon gates and local oxidation process technology. The chip interconnect consists of four levels: Aluminum, Polysi 2, Polysi 1, and P(+) and N(+) diffusions. The four levels, except for contact interface, are isolated by interlevel oxide. The chip is packaged in a 40-pin dual-in-line (DIP), side brazed, hermetically sealed, ceramic package with a metal lid. The operating voltage for the device is 5 V. It is available in three operating temperature ranges: 0 to +70 C, -40 to +85 C, and -55 to +125 C. Two devices were submitted for product evaluation by F. Stott, MTS, JPL Microprocessor Specialist. The devices were pencil-marked and photographed for identification.

  11. Grain refinement of an AZ63B magnesium alloy by an Al-1C master alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yichuan Pan; Xiangfa Liu; Hua Yang [The Key Lab. of Liquid Structure and Heredity of Materials, Shandong Univ., Jinan (China)

    2005-12-01

    In order to develop a refiner of Mg-Al alloys, an Al-1C (in wt.%) master alloy was synthesized using a casting method. The microstructure and grain-refining performance of the Al-1C master alloy were investigated using X-ray diffraction (XRD), electron probe microanalysis (EPMA) and a grain-refining test. The microstructure of the Al-1C master alloy is composed of {alpha}-Al solid solution, Al{sub 4}C{sub 3} particles, and graphite phases. After grain refinement of AZ63B alloy by the Al-1C master alloy, the mean grain size reached a limit when 2 wt.% Al-C master alloy was added at 800 C and held for 20 min in the melt before casting. The minimum mean grain size is approximately 48 {mu}m at the one-half radius of the ingot and is about 17% of that of the unrefined alloy. The Al-1C master alloy results in better grain refinement than C{sub 2}Cl{sub 6} and MgCO{sub 3} carbon-containing refiners. (orig.)

  12. 49 CFR 800.22 - Delegation to the Managing Director.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Delegation to the Managing Director. 800.22... Authority to Staff Members § 800.22 Delegation to the Managing Director. (a) The Board delegates to the Managing Director the authority to: (1) Make the final determination, on appeal, as to whether to...

  13. 31 CFR 800.102 - Effect on other law.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Effect on other law. 800.102 Section... TAKEOVERS BY FOREIGN PERSONS General § 800.102 Effect on other law. Nothing in this part shall be construed..., or review provided by or established under any other provision of federal law, including...

  14. 7 CFR 800.25 - Required elevator and merchandising records.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Required elevator and merchandising records. 800.25... REGULATIONS Recordkeeping and Access to Facilities § 800.25 Required elevator and merchandising records. (a... inspection or official weighing services other than (1) submitted sample inspection service, or (2)...

  15. 13 CFR 130.800 - Oversight of the SBDC program.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Oversight of the SBDC program. 130.800 Section 130.800 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS... funds for the benefit of the small business community....

  16. 31 CFR 800.401 - Procedures for notice.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Procedures for notice. 800.401 Section 800.401 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... certification required under paragraph (l) of that section; and (2) One electronic copy of the same...

  17. 31 CFR 800.206 - Convertible voting instrument.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Convertible voting instrument. 800..., AND TAKEOVERS BY FOREIGN PERSONS Definitions § 800.206 Convertible voting instrument. The term convertible voting instrument means a financial instrument that currently does not entitle its owner or...

  18. 21 CFR 522.800 - Droperidol and fentanyl citrate injection.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Droperidol and fentanyl citrate injection. 522.800... § 522.800 Droperidol and fentanyl citrate injection. (a) Specifications. Droperidol and fentanyl citrate injection is a sterile solution containing 20 milligrams of droperidol and 0.4 milligram of fentanyl...

  19. 7 CFR 800.76 - Prohibited services; restricted services.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Prohibited services; restricted services. 800.76..., PACKERS AND STOCKYARD ADMINISTRATION (FEDERAL GRAIN INSPECTION SERVICE), DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS Kinds of Official Services § 800.76 Prohibited services; restricted services. (a)...

  20. 31 CFR 800.214 - Foreign government-controlled transaction.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Foreign government-controlled transaction. 800.214 Section 800.214 Money and Finance: Treasury Regulations Relating to Money and Finance... control of a U.S. business by a foreign government or a person controlled by or acting on behalf of...

  1. Influence of helium and other impurities on mechanical properties of irradiated vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Manichev, V.M. [Rossijskij Nauchnyj Tsentr, Moscow (Russian Federation). Kurchatovskij Inst.; Ryazonov, A.I. [Rossijskij Nauchnyj Tsentr, Moscow (Russian Federation). Kurchatovskij Inst.; Witzenburg, W. van [Netherlands Energy Research Foundation (ECN), Petten (Netherlands)

    1994-09-01

    Helium preimplantation and neutron irradiation influence on the tensile properties of the vanadium alloys in the irradiation/test temperature range of 500-800 C was investigated and principal physical mechanisms of mechanical behaviour of irradiated alloys were considered. (orig.).

  2. Characterization of thermally stable Ir-Ta alloy thin films deposited by sputtering

    OpenAIRE

    Watanabe, E; Abe, Y.; Sasaki, K; Iura, S.; 阿部, 良夫; 佐々木, 克孝

    2004-01-01

    Ir-Ta alloy thin films were deposited on Si0_2/Si substrates by a magnetron sputtering system using pure Ar as sputtering gas. The lr/Ta composition ratio of the alloy films was varied by changing the number of Ta chips on an lr target. The crystal structure of the alloy films changed from fcc-Ir to lr_3Ta, α-(Ir,Ta), Ta_3Ir, and bcc-Ta with increasing Ta content. Post-deposition annealing of the alloy films was carried out in oxygen at temperatures from 300℃ to 800℃ for 1 hour. The alloy fil...

  3. Fused metallic slurry coatings for improving the oxidation resistance of wrought alloys

    OpenAIRE

    Segura-Cedillo, Ismael

    2011-01-01

    The aim of this project was to investigate the potential of fused-slurry coatings for improving the oxidation resistance of wrought alloys. Slurry-aluminised coatings were deposited on Alloy 800H (Fe-33Ni-20Cr), Alloy HCM12A (Fe-12Cr-2W), Alloy 214 (Ni-16Cr-4Al-3Fe), Fe-27Cr-4Al and Fe-14Cr-4Al alloys. The slurry contained a cellulose-based binder in an aqueous carrier and spherical aluminium powder, with a particle size below 20 microns. The slurries were applied with a paint-brush, dried in...

  4. Ordered iron aluminide alloys having an improved room-temperature ductility and method thereof

    Science.gov (United States)

    Sikka, Vinod K.

    1992-01-01

    A process is disclosed for improving the room temperature ductility and strength of iron aluminide intermetallic alloys. The process involves thermomechanically working an iron aluminide alloy by means which produce an elongated grain structure. The worked alloy is then heated at a temperature in the range of about 650.degree. C. to about 800.degree. C. to produce a B2-type crystal structure. The alloy is rapidly cooled in a moisture free atmosphere to retain the B2-type crystal structure at room temperature, thus providing an alloy having improved room temperature ductility and strength.

  5. Electrical Resistance Alloys and Low-Expansion Alloys

    DEFF Research Database (Denmark)

    Kjer, Torben

    1996-01-01

    The article gives an overview of electrical resistance alloys and alloys with low thermal expansion. The electrical resistance alloys comprise resistance alloys, heating alloys and thermostat alloys. The low expansion alloys comprise alloys with very low expansion coefficients, alloys with very low...

  6. Manufacturing of self-passivating W-Cr-Si alloys by mechanical alloying and HIP

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Ruiz, P. [CEIT and Tecnun (University of Navarra), E-20018 San Sebastian (Spain); Koch, F. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Ordas, N. [CEIT and Tecnun (University of Navarra), E-20018 San Sebastian (Spain); Lindig, S. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Garcia-Rosales, C., E-mail: cgrosales@ceit.es [CEIT and Tecnun (University of Navarra), E-20018 San Sebastian (Spain)

    2011-10-15

    Self-passivating tungsten-based alloys may provide a major safety advantage in comparison with pure tungsten, which is presently the main candidate material for the plasma-facing protection of future fusion power reactors. WCrSi alloys were manufactured by mechanical alloying (MA) and HIP at 1300 deg. C and 200 MPa for 1 h. Different MA conditions were investigated to obtain powders with lowest possible amount of contaminants and small and homogeneous particle and crystallite size. Milling in WC vials under Ar without process control agent provided best results. After HIP densities close to 100% were obtained. First oxidation tests on preliminary alloys showed self-passivating behavior with rates comparable to WCrSi thin films at 800 deg. C but worse performance at 1000 deg. C. In all cases a Cr{sub 2}WO{sub 6} protective layer is formed at the surface.

  7. Friction and wear behavior of electrodeposited amorphous Fe-Co-W alloy deposits

    Institute of Scientific and Technical Information of China (English)

    何凤姣; 雷惊天; 陆欣; 黄宇宁

    2004-01-01

    The microstructures, friction and wear behavior under dry sliding condition of electrodeposited amorphous Fe-Co-W alloy deposits heat treated at different temperatures were studied. A comparative study of hard chrome deposit under the same testing condition was also made. The experimental results show that the hardness and wear resistance of amorphous Fe-Co-W alloy deposits are improved with the increasing of heat treatment temperature, and reach the maximum value at 800 ℃, then decrease above 800 ℃. Under 40 N load, the wear resistance properties of the alloy deposits heat treated at 800 ℃ are superior to those of hard chrome deposit. The main wear mechanisms of amorphous Fe-Co-W alloy deposits heat treated below 600 ℃ are peeling, plastic and flowing deformation; when the deposits are heat treated above 700 ℃, they are plastic and flowing deformation. While the main wear mechanisms of hard chrome are abrasive wear, fatigue and peeling.

  8. 三星Samsung MST 800耳机

    Institute of Scientific and Technical Information of China (English)

    alfa

    2006-01-01

    三星MST 800是三星最新推出面向大众消费者的头戴式耳机.这个系列的耳机包括MST850和MST800两个型号。MST-800采用了40MM的振膜.在播放中音方面会有不俗的表现。这款产品的抗阻仅有32Ω.这样保证了耳机的适用性比较广.即使使用MP3或CD随身听也可以推动MST800

  9. 7 CFR 97.800 - Publication of public variety descriptions.

    Science.gov (United States)

    2010-01-01

    ... Section 97.800 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) COMMODITY... Office will be accepted for publication in the Official Journal. Such publication shall not...

  10. Microstructure and intergranular corrosion of Inconel-600 and Incoloy-800 tubes

    Energy Technology Data Exchange (ETDEWEB)

    Stickler, R.; Weidlich, G.

    1983-04-01

    The precipitation behavior and the resistance against intergranular corrosion was determined for specimens of tubes produced of alloys IN-600 and Incoloy 800. Specimens were sensitized by heat treatments in the time-temperature range between 0.1-100 h and 400-800 C. Light microscopic, scanning electron and transmission microscope methods in addition to X-ray diffraction analyses of bulk residues were applied to characterize microstructure and precipitates. A modified standard procedure was used to determine the susceptibility to intergranular corrosion. The occurrance of grain-boundary attack was evaluated by scanning electron microscope observations. The results indicate that in the time-temperature diagram the susceptibility to intergranular corrosion falls within a typical C-curve, the lower branch of which coincides with the formation of a thin M/sub 23/C/sub 6/ grain boundary film. It is interesting to note that occasionally grain boundary separation could be found after the bend test of tube specimen in the as-received and as-aged condition without any corrosion exposure. These observations may indicate difficulties in the evaluation of the intergranular corrosion attack.

  11. Crystallization temperatures of 5d--5d alloys

    Energy Technology Data Exchange (ETDEWEB)

    van der Kolk, G.J.

    1988-03-01

    Binary alloys of Re--Ta, Os--Ta, Ir--Ta, Os--W, and Ir--W were vapor deposited. A wide amorphous formation range was found for all systems, except Ir--W. The crystallization temperatures were generally very high: between 800 and 1000 K.

  12. Initial cytotoxicity of novel titanium alloys.

    Science.gov (United States)

    Koike, M; Lockwood, P E; Wataha, J C; Okabe, T

    2007-11-01

    We assessed the biological response to several novel titanium alloys that have promising physical properties for biomedical applications. Four commercial titanium alloys [Super-TIX(R) 800, Super-TIX(R) 51AF, TIMETAL(R) 21SRx, and Ti-6Al-4V (ASTM grade 5)] and three experimental titanium alloys [Ti-13Cr-3Cu, Ti-1.5Si and Ti-1.5Si-5Cu] were tested. Specimens (n = 6; 5.0 x 5.0 x 3.0 mm(3)) were cast in a centrifugal casting machine using a MgO-based investment and polished to 600 grit, removing 250 mum from each surface. Commercially pure titanium (CP Ti: ASTM grade 2) and Teflon (polytetrafluoroethylene) were used as positive controls. The specimens were cleaned and disinfected, and then each cleaned specimen was placed in direct contact with Balb/c 3T3 fibroblasts for 72 h. The cytotoxicity [succinic dehydrogenase (SDH) activity] of the extracts was assessed using the MTT method. Cytotoxicity of the metals tested was not statistically different compared to the CP Ti and Teflon controls (p > 0.05). These novel titanium alloys pose cytotoxic risks no greater than many other commonly used alloys, including commercially pure titanium. The promising short-term biocompatibility of these Ti alloys is probably due to their excellent corrosion resistance under static conditions, even in biological environments. PMID:17385227

  13. Biocorrosion study of titanium-cobalt alloys.

    Science.gov (United States)

    Chern Lin, J H; Lo, S J; Ju, C P

    1995-05-01

    The present work provides experimental results of corrosion behaviour in Hank's physiological solution and some other properties of in-house fabricated titanium-cobalt alloys with cobalt ranging from 25-30% in weight. X-ray diffraction (XRD) shows that, in water-quenched (WQ) alloys, beta-titanium is largely retained, whereas in furnace-cooled (FC) alloys, little beta-titanium is found. Hardness of the alloys increases with increasing cobalt content, ranging from 455 VHN for WQ Ti-25 wt% Co to 525 VHN for WQ Ti-30 wt% Co. Differential thermal analysis (DTA) indicates that melting temperatures of the alloys are lower than that of pure titanium by about 600 degrees C. Potentiodynamic polarization results show that all measured break-down potentials in Hank's solution at 37 degrees C are higher than 800 mV. The breakdown potential for the FC Ti-25 Wt% Co alloy is even as high as nearly 1200 mV.

  14. Initial cytotoxicity of novel titanium alloys.

    Science.gov (United States)

    Koike, M; Lockwood, P E; Wataha, J C; Okabe, T

    2007-11-01

    We assessed the biological response to several novel titanium alloys that have promising physical properties for biomedical applications. Four commercial titanium alloys [Super-TIX(R) 800, Super-TIX(R) 51AF, TIMETAL(R) 21SRx, and Ti-6Al-4V (ASTM grade 5)] and three experimental titanium alloys [Ti-13Cr-3Cu, Ti-1.5Si and Ti-1.5Si-5Cu] were tested. Specimens (n = 6; 5.0 x 5.0 x 3.0 mm(3)) were cast in a centrifugal casting machine using a MgO-based investment and polished to 600 grit, removing 250 mum from each surface. Commercially pure titanium (CP Ti: ASTM grade 2) and Teflon (polytetrafluoroethylene) were used as positive controls. The specimens were cleaned and disinfected, and then each cleaned specimen was placed in direct contact with Balb/c 3T3 fibroblasts for 72 h. The cytotoxicity [succinic dehydrogenase (SDH) activity] of the extracts was assessed using the MTT method. Cytotoxicity of the metals tested was not statistically different compared to the CP Ti and Teflon controls (p > 0.05). These novel titanium alloys pose cytotoxic risks no greater than many other commonly used alloys, including commercially pure titanium. The promising short-term biocompatibility of these Ti alloys is probably due to their excellent corrosion resistance under static conditions, even in biological environments.

  15. Electron beam welding and laser welding of steam generator tubes made of alloy 800

    International Nuclear Information System (INIS)

    The electron beam welding conditions are optimized for different thermal cycles and chemical compositions of the fusion zone. The metallurgical and mechanical properties of the joints are described and compared with the properties of laser and TIG welds

  16. Fatigue Properties of TRIP800 Steel Plate%TRIP800钢板疲劳性能研究

    Institute of Scientific and Technical Information of China (English)

    于燕; 杨海峰

    2012-01-01

    对厚度为1.8mm的国产TRIP800 MPa钢板进行疲劳试验,并运用最小二乘法对试验数据进行拟合,获得了在对称循环应力下的疲劳经验公式.结果表明:TRIP800 MPa钢板在加载频率为8Hz、R=0的条件下疲劳极限是560MPa;TRIP800钢板的疲劳裂纹源位于表面下的夹杂物处,裂纹扩展区为韧性断裂,瞬断区为脆性断裂.%A fatigue life test was carried out on 1.8 mm domestic TRIP800 MPa steel plate. The least square method was used to fit, and then the symmetrical cyclic stress of fatigue experience formula was obtained. The results show that TRIP800 MPa steel plate loading for 8 Hz in frequency, R=0 condition: fatigue limit is 560 MPa. TRIP800 steel plate fatigue crack source is located under the surface of the inclusion place, crack growth area for the ductile fracture, transient breaking area for the brittle fiacture.

  17. Wenshan’s 800,000-ton Alumina Project Completed

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>On September 26,2012,the completion ceremony of the 800,000-ton alumina project was held at the alumina factory in Matang Industrial Park, Wenshan city,Yunnan.Wenshan’s 800,000-ton alumina project and its supporting mining construction projects have been listed as one of 20 major industrial construction projects of Yunnan. The project covers an area of approximately 5,500 mu,with an estimated total investment of RMB 4,987 million. It is invested and built

  18. Hot deformation behavior of a near alpha titanium alloy with/without thermal hydrogen processing

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The true stress-true strain curves of Ti-6Al-2Zr-1Mo-1V alloy with hydrogen were obtained by hot compression test.The microstructures of the alloy before and after thermo-compression were observed.The apparent activation energies of deformation were calculated for the alloy with and without hydrogen.The behavior and mechanism of deformation for hydrogenated Ti-6Al-2Zr-1Mo-1V alloy at high temperature were analyzed.The relationship between hydrogenation time and hydrogen content at 800 ℃ can be expressed as ...

  19. Study of Titanizing the Surface of Copper Substrates by the Double Glow Discharge Plasma Surface Alloying Technique

    Institute of Scientific and Technical Information of China (English)

    Zhang Yuefei; Chen Fei; Lü Junxia; Su Yongan; Xu Zhong

    2005-01-01

    This paper discusses a study in which Ti surface alloying has been performed on copper substrates by means of a double glow discharge plasma surface alloying technique. The micro-structure, the phase structure, the micro-hardness and the distribution of Ti concentration of alloying layer were investigated in detail by XRD, SEM and so on. The effect of process parameters on the alloying layer was studied. The experimental results show that a Ti solid solution with the precipitation Cu4Ti alloying layer has been formed on the copper surface. The thickness of the alloying layer is about 120μm and the surface titanium concentration gradually decreases from w (Ti) = 87% to w (Ti) = 4%. The micro-hardness of the alloying layer is between 300 HV ~ 800 HV. Source sputtering, surface absorption, ion bombarding and high temperature diffusion are the major factors that affect the alloying layer.

  20. Magna Carta at 800: Ten Key Questions Answered

    Science.gov (United States)

    Kaplan, Howard

    2014-01-01

    2015 marks the 800th anniversary of Magna Carta. For Americans, this iconic document is a formative element of our own legal and political heritage. This "Lessons on the Law" column offers an overview of the "Great Charter," why it is significant, and what students and teachers should know about it. The article also highlights…

  1. 30 CFR 800.23 - Self-bonding.

    Science.gov (United States)

    2010-07-01

    ...-parent corporate guarantee.” The terms of this guarantee shall provide for compliance with the conditions... FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS UNDER REGULATORY PROGRAMS § 800.23 Self-bonding. (a... section as if it were the applicant. Such a written guarantee shall be referred to as a...

  2. Note on the development of a 800 kv acceleration tube

    NARCIS (Netherlands)

    Veenstra, P.C.; Jongerius, H.M.; Paris, C.H.; Valckx, F.P.G.

    1952-01-01

    A description is given of the present acceleration tube and ion-source in use with the 800 kV cascade-generator. The ion-source is of the magnetic type operating with cold emission ensuring reliability and low power consumption. The importance is stressed of good focussing and experiments are descri

  3. Low-aluminum content iron-aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J. [and others

    1995-06-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10 and iron = 83.71. The ignots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot-worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  4. Wear and isothermal oxidation kinetics of nitrided TiAl based alloys

    Institute of Scientific and Technical Information of China (English)

    赵斌; 吴建生; 孙坚

    2002-01-01

    Gas nitridation of TiAl based alloys in an ammonia atmosphere was c arried out. The evaluation of the surface wear resistance was performed to compare with those of the non-nitrided alloys. It is concluded that high temperature nitridation raised wear resistance of TiAl based alloys markedly. The tribol ogical behaviors of the nitrided alloys were also discussed. The oxidation kinetics of the nitrided TiAl based alloys were investigated at 800~1000 ℃ in hot air. It is concluded that nitridation is detrimental to the oxidation resistance of TiAl based alloys under the present conditions. The nitrided alloys exhibit increased oxidizing rate with the prolongation of nitridation time at 800 ℃. However, alloys nitrided at 940 ℃ for 50 hdisplay a sign of better oxidat ion resistance than the other nitrided alloys at more severe oxidizing conditions. The parabolic rate law is considered as the basis of the data processing and interpretation of the mass gainvs time data. As a comparison with it, attempts were made to fit the data with the power law. The oxidation kinetic parameter kn, kp and n were measured and the trends were discussed.

  5. 75 FR 35315 - Improving Public Safety Communications in the 800 MHz Band; New 800 MHz Band Plan for Puerto Rico...

    Science.gov (United States)

    2010-06-22

    ... public safety and other land mobile communication systems operating in the band, 69 FR 67823, November 22... Puerto Rico market compared to other markets, 72 FR 39756, July 20, 2007. Rather than specify a band plan... 800 MHz band reconfiguration in Puerto Rico as well as alternative band plans, 73 FR 40274, July...

  6. Metal alloy identifier

    Science.gov (United States)

    Riley, William D.; Brown, Jr., Robert D.

    1987-01-01

    To identify the composition of a metal alloy, sparks generated from the alloy are optically observed and spectrographically analyzed. The spectrographic data, in the form of a full-spectrum plot of intensity versus wavelength, provide the "signature" of the metal alloy. This signature can be compared with similar plots for alloys of known composition to establish the unknown composition by a positive match with a known alloy. An alternative method is to form intensity ratios for pairs of predetermined wavelengths within the observed spectrum and to then compare the values of such ratios with similar values for known alloy compositions, thereby to positively identify the unknown alloy composition.

  7. POWDER METALLURGY TiAl ALLOYS: MICROSTRUCTURES AND PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, L

    2006-12-11

    The microstructures and properties of powder metallurgy TiAl alloys fabricated by hot extrusion of gas-atomized powder at different elevated temperatures were investigated. Microstructure of the alloy fabricated at 1150 C consisted of a mixture of fine ({gamma} + {alpha}{sub 2}) equiaxed grains and coarse ordered B2 grains. Particles of ordered hexagonal {omega} phase were also observed in some B2 grains. The alloy containing B2 grains displayed a low-temperature superplastic behavior: a tensile elongation of 310% was measured when the alloy was tested at 800 C under a strain rate of 2 x 10{sup -5} s{sup -1}. Microstructure of the alloy fabricated at 1250 C consisted of a mixture of fine ({gamma} + {alpha}{sub 2}) equiaxed grains, coarse {alpha}{sub 2} grains, and lamellar ({gamma} + {alpha}{sub 2}) colonies. An observation of stacking faults associated with fine {gamma} lamellae in {alpha}{sub 2} grains reveals that the stacking fault of {alpha}{sub 2} phase plays an important role in the formation of lamellar ({gamma} + {alpha}{sub 2}) colonies. Unlike the alloy fabricated at 1150{sup o}, the alloy fabricated at 1250{sup o} displayed no low-temperature superplasticity, but a tensile elongation of 260% at 1000 C was measured. Microstructure of the alloy fabricated at 1400 C consisted of fully lamellar ({gamma} + {alpha}{sub 2}) colonies with the colony size ranging between 50 {micro}m and 100 {micro}m, in which the width of {gamma} lamella is in a range between 100 nm and 350 nm, and the width of {alpha}{sub 2} lamella is in a range between 10 nm and 50 nm. Creep behavior of the ultrafine lamellar alloy and the effects of alloying addition on the creep resistance of the fully lamellar alloy are also investigated.

  8. JAZZ-800信号处理器

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Miranda推出的JAZZ-800是一个仅1RU的单/双通道通用信号处理器,它结合高性能的信号处理功能和便捷的操作控制,提供了上/下/交叉/ARC和高/标清变换功能,以及数/模之间的转换功能,适合多信号的工作环境。JAZZ-800配备带功能菜单和视频监视的本地控制面板,具备噪音屏蔽的高/标清画面显示,

  9. 800MHz Crab Cavity Conceptual Design For the LHC Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Liling; Li, Zenghai; Ng, Cho-Kuen; Seryi, Andrei; /SLAC

    2009-05-26

    In this paper, we present an 800 MHz crab cavity conceptual design for the LHC upgrade. The cell shape is optimized for lower maximum peak surface fields as well as higher transverse R/Q. A compact coax-to-coax coupler scheme is proposed to damp the LOM/SOM modes. A two-stub antenna with a notch filter is used as the HOM coupler to damp the HOM modes in the horizontal plane and rejects the operating mode at 800MHz. Multipacting (MP) simulations show that there are strong MP particles at the disks. Adding grooves along the short axis without changing the operating mode's RF characteristics can suppress the MP activities. Possible input coupler configurations are discussed.

  10. Densities of Some Low Melting Plutonium Alloys

    International Nuclear Information System (INIS)

    The change in fuel density with temperature is an important parameter in nuclear reactor design. For molten fuels, such as are used in LAMPRE-type reactor it is also necessary to know the volume change on melting. A volumeter employing NaK as a working fluid was used to obtain'these data for various plutonium and cerium base alloys over the range 25-800°C. Cerium and several low-melting binary cerium alloys were studied with this equipment. Cerium, Ce-Co, Ce-Ni, and Ce-Cu alloys all exhibit an increase in density on melting, while a Ce-Mn alloy expands on melting. The melting temperatures of several of these alloys differ from those reported in the literature, and the compositions of several eutectics in these systems are also reported incorrectly. The densities of unstabilized and gallium- stabilized plutonium and Pu-10 at.% Fe were measured and compared over this temperature range. All these materials expand on freezing. At 675°C, molten unstabilized plutonium is approximately 2% more dense than Pu-l wt.% Ga alloy. Molten Pu-Fe alloy containing 0.2 wt.% Ga at 435°C is 0.8% less dense than unstabilized alloy. This indicates that there is short-range ordering of plutonium atoms by gallium in the liquid state. The materials containing gallium melted over a 20°C temperature range, while the unstabilized materials melted sharply. Pu-Co-Ce alloys containing 3, 5, 6.2 and 8 g Pu/cm3 were investigated. They all melt in the range 425-442°C and expand on freezing. This expansion increases with increasing plutonium content from 1.3% for the 3 g Pu/cm3 alloy to 3% for the 8 g Pu/cm3 material. Manganese additions to this fuel system are being studied in an attempt to reduce this expansion on freezing. (author)

  11. Characterization of an 800 nm SASE FEL at saturation

    CERN Document Server

    Tremaine, Aaron M; Ben-Zvi, I; Bertolini, L R; Carr, R; Cornacchia, M; Frigola, P; Hill, J M; Johnson, E; Klaisner, L; Le Sage, G P; Libkind, M; Malone, R; Murokh, A; Nuhn, H D; Pellegrini, C; Rakowsky, G; Reiche, S; Rosenzweig, J; Ruland, R; Skaritka, J; Toor, A; Van Bibber, K A; Wang, X J

    2002-01-01

    Visible to Infrared SASE Amplifier is a free electron laser (FEL) designed to saturate at a radiation wavelength of 800 nm within a 4 m long, strong focusing undulator. Large gain is achieved by driving the FEL with 72 MeV, high brightness beam of BNL's accelerator test facility. We present measurements that demonstrate saturation in addition to the frequency spectrum of the FEL radiation. Energy, gain length and spectral characteristics are compared and shown to agree with simulation and theoretical predictions.

  12. Characterization of the SPS 800MHz travelling wave cavities.

    CERN Document Server

    Bazyl, Dmitry

    2015-01-01

    It is well known that HOMs in RF cavities are a potentially dangerous source of beam impedance. Therefore, HOMs (both longitudinal and transverse) can drive the beam unstable . The 800MHz cavities of the SPS were studied in the past. However, very little documentation was left behind. Currently, the performance of the SPS is limited by a longitudinal beam instability. In order to study this instability, an accurate impedance model of the whole SPS is needed.

  13. Alloyed steel

    International Nuclear Information System (INIS)

    The composition and properties are listed of alloyed steel for use in the manufacture of steam generators, collectors, spacers, emergency tanks, and other components of nuclear power plants. The steel consists of 0.08 to 0.11% w.w. C, 0.6 to 1.4% w.w. Mn, 0.35 to 0.6% w.w. Mo, 0.02 to 0.07% w.w. Al, 0.17 to 0.37% w.w. Si, 1.7 to 2.7% w.w. Ni, 0.03 to 0.07% w.w. V, 0.005 to 0.012% w.w. N, and the rest is Fe. The said steel showed a sufficiently low transition temperature between brittle and tough structures, a greater depth of hardenability, and better weldability than similar steels. (B.S.)

  14. Femtosecond Dynamics of Energy Transfer in Native B800-B850 and B800-Released LH2 Complexes of Rhodobacter Sphaeroides

    Institute of Scientific and Technical Information of China (English)

    刘伟民; 朱荣毅; 夏辰安; 刘源; 徐春和; 钱士雄

    2003-01-01

    Two kinds of antenna complexes LH2 of Rhodobacter sphaeroides, wild type RS601 and the removal of B800 pigments (B800-released), were used in our experiment. These two LH2 complexes show quite different behaviour in absorption and femtosecond dynamics. By using the femtosecond pump-probe technique, the energy transfer processes occurring in two complexes were studied. Because of removing the B800 pigment from the LH2 in B800-released LH2 complex, the energy transfer between the B800 to B850 pigment was completely eliminated,while the pure internal energy transfer within the exciton states of B850 pigment could be carefully investigated.The results show that, at B800 absorption band, B800-released LH2 obviously shows a dominated transient absorption different from the photobleaching observed in RS601; while at the B850 band, these two complexes show similar photobleaching behaviour.

  15. INFLUENCE OF AGEING ON THE INTERNAL FRICTION OF Nb-Ti-N ALLOYS

    OpenAIRE

    Heulin, B.; Clauss, A.

    1981-01-01

    We have studied the influence of ageing on the internal friction of various Nb-4.6Ti-N alloys at 1Hz, annealed for 24 hours at 400, 600, and 800°C. This study shows the influence of temperature, beginning at 400°C, on the measurements of internal friction and allows a more complete description of the structure and behaviour of Nb-Ti-N alloys.

  16. Mechanical Properties of Fuel Cladding Candidate Alloys for Canadian SCWR Concept

    Science.gov (United States)

    Xu, Su; Amirkhiz, Babak Shalchi

    2016-02-01

    An assessment of tensile and creep of five representative candidate fuel cladding alloys for a Canadian Gen IV super-critical water reactor concept was performed based on database development work and complementary experiments including a transmission electron microscopy study of creep in stainless steels. The limiting property would be creep strength of candidate alloys for the "free-standing" fuel cladding design with a hot-spot peak temperature range of 1073-1123 K (800-850°C).

  17. Sports Biomechanical Analysis on 800 Meters Running%800 m跑运动生物力学分析

    Institute of Scientific and Technical Information of China (English)

    纪仲秋; 姜桂萍; 汤海鹏; 周之华

    1999-01-01

    对运动员在800 m跑比赛中的技术动作进行生物力学分析,分析了身体重心、下肢动作、机械能量和能量有效性,其结果有利于改进技术,并为指导训练提供参考依据.

  18. Residual stresses determination in an 8 mm Incoloy 800H weld via neutron diffraction

    International Nuclear Information System (INIS)

    Highlights: • Stress through thickness at 5 mm from weld centerline indicates a “U” distribution. • Declining of tensile stress through thickness occurred at weld centerline. • Residual stress between layers is the lowest. - Abstract: To investigate the distribution of residual stresses, the 8 mm 800H alloy was joined by multi-layer butt TIG process. Residual stresses in the longitudinal, transverse and normal directions were measured via neutron diffraction. These residual stress measurements were taken at a series of points 2 mm below the top surface, covering the fusion zone, heat affected zone (HAZ) and base metal. In addition, two lines of longitudinal residual stress values at the weld centerline and 5 mm from weld centerline through thickness were measured. Results show that both the longitudinal and transverse stresses from the weld centerline to base metal are mainly tensile stresses. The longitudinal residual stress is the largest, with a maximum value of 330 MPa. As for the normal residual stress, the weld zone shows tensile stress, while the HAZ shows compressive stress. The middle of the thickness shows compressive residual stress along the thickness direction. The longitudinal stress at weld centerline through thickness reveals the interlayer heat treat effects leads to a declining of tensile stress. While the stress at 5 mm from weld centerline indicates a “U” distribution due to the mixed microstructure close to fusion line. With the increasing distance from weld seam, the residual stress decreases gradually

  19. Mechanical alloying in immiscible alloy systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In recent years, mechanical alloying (MA) of immiscible alloy systems characterized by positive heat of mixing has been extensively investigated. The present article reviews the latest progress in MA of immiscible alloy systems including the mechanisms of non-equilibrium phase transformation and metastable phase formation of the MA-driven supersaturated solid solutions, amorphous phases and nanophase composites as well as their mechanical and physical properties related to those metastable phases.

  20. Cryogenic design of a 800 kJ HTS SMES

    Energy Technology Data Exchange (ETDEWEB)

    Bellin, B [CNRS-CRTBT/LEG, B.P. 166, 38 042 Grenoble Cedex 09 (France); Tixador, P [CNRS-CRTBT/LEG, B.P. 166, 38 042 Grenoble Cedex 09 (France); Deleglise, M [SERAS, B.P. 166, 38 042 Grenoble Cedex 09 (France); Vallier, J C [CNRS-CRTBT, B.P. 166, 38 042 Grenoble Cedex 09 (France); Pavard, S [NEXANS, 31 rue Industrie 59460 Jeumont (France); Bruzek, C E [NEXANS, 31 rue Industrie 59460 Jeumont (France)

    2006-06-01

    In the context of a DGA (Delegation Generale pour l'Armement) project, we have designed a 800 kJ SMES. The conductor is made with 3 or 4 Bi-2212 PIT tapes insulated and assembled by Nexans France. The operating temperature is 20 K. The cryogenic design of the SMES is presented. The thermal operation model was calculated using FLUX[reg], a F.E.M. (Finite Element Model) software. We present the results of the measurements of thermal and electrical resistances and the results of the tests on a small-scale double pancake coil.

  1. Alloy Fabrication Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL’s Alloy Fabrication Facility in Albany, OR, researchers conduct DOE research projects to produce new alloys suited to a variety of applications, from gas...

  2. The replicon of pSW800 from Pantoea stewartii.

    Science.gov (United States)

    Wu, C Y; Fu, J F; Liu, S T

    2001-10-01

    A 2019 bp DNA fragment containing the replicon of pSW800 from Pantoea stewartii SW2 was cloned and characterized. This replicon contains two genes--repA and repB, which encode a 36.5 kDa replication initiation protein (RepA) and a peptide of 18 aa, respectively. These two genes overlap by 8 bases with repB situated upstream. The replicon also transcribes an antisense RNA (RNAI) that inhibits the expression of repA and repB. The ribosome-binding sequence (RBS) of repA is likely to be hidden in a stem-loop structure, inhibiting the translation of repA. Furthermore, translation of repB is likely to disrupt the stem-loop structure, which is one of the criteria allowing the translation of repA to begin. A mutagenesis study revealed that a sequence (5'-GCACGGG-3') located 111 nt upstream from repA is crucial; mutation of this sequence prevented the translation of repA. Additionally, this region and the stem-loop structure containing the RBS of repA may form an RNA pseudoknot. Results in this study demonstrate that a mechanism similar to that regulating plasmid replication in the IncB, IncIalpha and IncL/M groups also regulates pSW800 replication. PMID:11577155

  3. PLUTONIUM-THORIUM ALLOYS

    Science.gov (United States)

    Schonfeld, F.W.

    1959-09-15

    New plutonium-base binary alloys useful as liquid reactor fuel are described. The alloys consist of 50 to 98 at.% thorium with the remainder plutonium. The stated advantages of these alloys over unalloyed plutonium for reactor fuel use are easy fabrication, phase stability, and the accompanying advantuge of providing a means for converting Th/sup 232/ into U/sup 233/.

  4. Thermal stability of the cellular structure of an austenitic alloy after selective laser melting

    Science.gov (United States)

    Bazaleeva, K. O.; Tsvetkova, E. V.; Balakirev, E. V.; Yadroitsev, I. A.; Smurov, I. Yu.

    2016-05-01

    The thermal stability of the cellular structure of an austenitic Fe-17% Cr-12% Ni-2% Mo-1% Mn-0.7% Si-0.02% C alloy produced by selective laser melting in the temperature range 20-1200°C is investigated. Metallographic analysis, transmission electron microscopy, and scanning electron microscopy show that structural changes in the alloy begin at 600-700°C and are fully completed at ~1150°C. Differential scanning calorimetry of the alloy with a cellular structure reveals three exothermic processes occurring upon annealing within the temperature ranges 450-650, 800-1000, and 1050-1200°C.

  5. Strength and fracture of uranium, plutonium and several their alloys under shock wave loading

    OpenAIRE

    Golubev V.K.

    2012-01-01

    Results on studying the spall fracture of uranium, plutonium and several their alloys under shock wave loading are presented in the paper. The problems of influence of initial temperature in a range of − 196 – 800∘C and loading time on the spall strength and failure character of uranium and two its alloys with molybdenum and both molybdenum and zirconium were studied. The results for plutonium and its alloy with gallium were obtained at a normal temperature and in a temperature range of 40–31...

  6. Mechanisms Governing the Creep Behavior of High Temperature Alloys for Generation IV Nuclear Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Vijay [Univ. of Cincinnati, OH (United States); Carroll, Laura [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sham, Sam [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-04-06

    This research project, which includes collaborators from INL and ORNL, focuses on the study of alloy 617 and alloy 800H that are candidates for applications as intermediate heat exchangers in GEN IV nuclear reactors, with an emphasis on the effects of grain size, grain boundaries and second phases on the creep properties; the mechanisms of dislocation creep, diffusional creep and cavitation; the onset of tertiary creep; and theoretical modeling for long-term predictions of materials behavior and for high temperature alloy design.

  7. Investigations on crack growth in heat exchanging components with working temperatures above 800degC - a contribution to a HTR safety concept (SR 343)

    International Nuclear Information System (INIS)

    Experiments on the transferability of fracture mechanics data to thick walled tubes have been performed with the materials X10NiCrAlTi 32 20 (Alloy 800 H) and NiCr 22 Co 12 Mo (Inconel 617). The fatigue crack growth is well described by the linear elastic concept up to the highest testing temperatures (900degC). For the description of the creep crack propagation in tubes the parameter 'energy rate integral' seems to be suitable. (orig./HP)

  8. Comprehensive Assessment of SPJ-800 Belt Conveyor%SPJ-800型带式输送机的综合评定

    Institute of Scientific and Technical Information of China (English)

    杜志远

    2011-01-01

    经对SPJ-800型带式输送机的综合评定,得出结论:SPJ-800型带式输送机B=800 nun,V=1.6 m/s,N=2×37 kW,L=370 β尹=2.50,Q=26°,Q-=260/h,满足生产要求;输送带选用PVG800S阻燃抗静电带,额定拉断力Sn=0.8×10(6)N,满足强度要求.

  9. Response of metallic glasses Fe40Ni40P14B6 and Fe80B20 to irradiation with 800-MeV protons

    International Nuclear Information System (INIS)

    Metallic glasses with compositions of Fe40Ni40P14B6 and Fe80B20 were irradiated in the 800 MeV proton beam at the Los Alamos Meson Physics Facility while the electrical resistance and length changes were monitored. The resistance and the length of the first alloy were both found to increase and saturate with dose to ΔR/R approx. = 5 x 10-3 and ΔL/L approx. = 2 x 10-3. For the second alloy the total dose of 1.1 x 1019 p/cm2, which was calculated to give roughly 0.12 dpa, was slightly less than that required for saturation. No annealing of these increases was observed for anneals from room temperature to 2500C. These results are interpreted in terms of a model in which collision cascades create small regions of increased atomic disorder which fully overlap each other at saturation

  10. 7 CFR 800.177 - Automatic suspension of license by change in employment.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Automatic suspension of license by change in employment. 800.177 Section 800.177 Agriculture Regulations of the Department of Agriculture (Continued... AGRICULTURE GENERAL REGULATIONS Licenses and Authorizations (for Individuals Only) § 800.177...

  11. 7 CFR 800.73 - Computation and payment of service fees; general fee information.

    Science.gov (United States)

    2010-01-01

    ... AGRICULTURE GENERAL REGULATIONS Fees § 800.73 Computation and payment of service fees; general fee information... 7 Agriculture 7 2010-01-01 2010-01-01 false Computation and payment of service fees; general fee information. 800.73 Section 800.73 Agriculture Regulations of the Department of Agriculture (Continued)...

  12. High strength alloys

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, Phillip James; Shingledecker, John Paul; Santella, Michael Leonard; Schneibel, Joachim Hugo; Sikka, Vinod Kumar; Vinegar, Harold J.; John, Randy Carl; Kim, Dong Sub

    2012-06-05

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tublar that is at least partially made from a material containing at least one of the metal alloys.

  13. High strength alloys

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX

    2010-08-31

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.

  14. Viscosity of In and In-Sb alloys

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The dynamic viscosity of pure In, In-1%Sb (mass fraction, so as the follows) alloy, In-55%Sb hypoeutectic alloyand In-69.5%Sb eutectic alloy was measured by using a torsional oscillation viscometer at different temperatures above liq-uidus. The experimental results show that the viscosity of these melts decreases with increasing temperature. The anomalouschange of viscosity occurs at about 430 and 470℃ in pure In melt. The variation of viscosity with temperature well meetsexponential correlation and no anomalous change occurs in measured temperature range in the In-1%Sb alloy melt. A tran-sition occurs at about 800℃ in both of In-55%Sb and In-69.5%Sb alloy melts. The sudden change of viscosity suggests thestructure change of melts. DSC (differential scanning calorimetry) curves of In-1%Sb alloy during heating and cooling weremeasured, and the results show that no structural variation in In-1%Sb alloy melt was testified further. In addition, the vis-cosity of In melt decreases with the addition of 1%Sb.

  15. Liquid structure and viscosity of In80Cu20 alloy

    Institute of Scientific and Technical Information of China (English)

    程素娟; 王忠华; 边秀房; 秦绪波; 司鹏超

    2004-01-01

    The structure and dynamic viscosity of In80Cu20 alloy melt in the temperature range from 600 ℃ to 1 000℃ were investigated by using a high-temperature X-ray diffractometer and a torsional oscillation viscometer. The experiments show that there exist medium range order (MRO) structures in In80Cu20 alloy melt in a low temperature range above liquidus. The MRO structures are weakened with increasing temperature and disappear when the temperature surpasses 800 ℃. The nearest interatomic distance r1 and the coordination number Ns of In80Cu20 alloy melt decrease as temperature increases from 650 ℃ to 1 000 ℃. Thermal contraction of atom clusters can be found in the heating process. The viscosity of In80Cu20 alloy melt drops as temperature increases and meets with the exponential relation. No sudden change in structure occurs in the measured temperature range. DSC curve of In80Cu20 alloy during cooling process was measured. It is found that there is no noticeable variation of heat during cooling from 1000 ℃ to 600 ℃ , which testifies further that there is no sudden change in structure of In80Cu20 alloy melt.

  16. Multipole Stack for the 800 MeV PS Booster

    CERN Multimedia

    1975-01-01

    The 800 MeV PS Booster had seen first beam in its 4 superposed rings in 1972, routine operation began in 1973. In the strive for ever higher beam intensities, the need for additional multipole lenses became evident. After detailed studies, the manufacture of 8 stacks of multipoles was launched in 1974. Each stack consists of 4 superposed multipoles and each multipole has 4 concentric shells. From the innermost to the outermost shell, Type A contains octupole, skew-octupole, sextupole, skew-sextupole. Type B contains skew-octupole, skew-sextupole, vertical dipole, horizontal dipole. Completion of installation in 1976 opened the way to higher beam intensities. M. Battiaz is seen here with a multipole stack and its many electrical connections.

  17. Creep Resistant Zinc Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Frank E. Goodwin

    2002-12-31

    This report covers the development of Hot Chamber Die Castable Zinc Alloys with High Creep Strengths. This project commenced in 2000, with the primary objective of developing a hot chamber zinc die-casting alloy, capable of satisfactory service at 140 C. The core objectives of the development program were to: (1) fill in missing alloy data areas and develop a more complete empirical model of the influence of alloy composition on creep strength and other selected properties, and (2) based on the results from this model, examine promising alloy composition areas, for further development and for meeting the property combination targets, with the view to designing an optimized alloy composition. The target properties identified by ILZRO for an improved creep resistant zinc die-casting alloy were identified as follows: (1) temperature capability of 1470 C; (2) creep stress of 31 MPa (4500 psi); (3) exposure time of 1000 hours; and (4) maximum creep elongation under these conditions of 1%. The project was broadly divided into three tasks: (1) Task 1--General and Modeling, covering Experimental design of a first batch of alloys, alloy preparation and characterization. (2) Task 2--Refinement and Optimization, covering Experimental design of a second batch of alloys. (3) Task 3--Creep Testing and Technology transfer, covering the finalization of testing and the transfer of technology to the Zinc industry should have at least one improved alloy result from this work.

  18. Biocompatibility of dental alloys

    Energy Technology Data Exchange (ETDEWEB)

    Braemer, W. [Heraeus Kulzer GmbH and Co. KG, Hanau (Germany)

    2001-10-01

    Modern dental alloys have been used for 50 years to produce prosthetic dental restorations. Generally, the crowns and frames of a prosthesis are prepared in dental alloys, and then veneered by feldspar ceramics or composites. In use, the alloys are exposed to the corrosive influence of saliva and bacteria. Metallic dental materials can be classified as precious and non-precious alloys. Precious alloys consist of gold, platinum, and small amounts of non-precious components such as copper, tin, or zinc. The non-precious alloys are based on either nickel or cobalt, alloyed with chrome, molybdenum, manganese, etc. Titanium is used as Grade 2 quality for dental purposes. As well as the dental casting alloys, high purity electroplated gold (99.8 wt.-%) is used in dental technology. This review discusses the corrosion behavior of metallic dental materials with saliva in ''in vitro'' tests and the influence of alloy components on bacteria (Lactobacillus casei and Streptococcus mutans). The test results show that alloys with high gold content, cobalt-based alloys, titanium, and electroplated gold are suitable for use as dental materials. (orig.)

  19. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W.; Ren, W. [Oak Ridge National Lab., TN (United States)

    1996-08-01

    Materials properties were collected for the design and construction of structural components for use in advanced heat recovery and hot gas cleanup systems. Alloys systems included 9Cr-1Mo-V steel, modified 316 stainless steel, modified type 310 stainless steel, modified 20Cr-25Ni-Nb stainless steel, modified alloy 800, and two sulfidation resistant alloys: HR160 and HR120. Experimental work was undertaken to expand the databases for potentially useful alloys. Types of testing included creep, stress-rupture, creep-crack growth, fatigue, and post-exposure short-time tensile tests. Because of the interest in relatively inexpensive alloys for service at 700{degrees}C and higher, research emphasis was placed on a modified type 310 stainless steel and a modified 20Cr-25Ni-Nb stainless steel. Both steels were found to have useful strength to 925{degrees}C with good weldability and ductility.

  20. Fabrication and Spark Plasma Sintering of Magnetic alpha-Fe/MgO Nanocomposite by Mechanical Alloying.

    Science.gov (United States)

    Lee, Chung-Hyo

    2016-02-01

    Solid-state reduction has occurred during mechanical alloying of a mixture of Fe2O3 and Mg powders at room temperature. It is found that magnetic nanocomposite in which MgO is dispersed in alpha-Fe matrix with nano-sized grains is obtained by mechanical alloying of Fe2O3 with Mg for 30 min. Consolidation of the ball-milled powders was performed in a spark plasma sintering (SPS) machine up to 800-1000 degrees C. X-ray diffraction result shows that the average grain size of alpha-Fe in a-Fe/MgO nanocomposite sintered at 800 degrees C is in the range of 110 nm. It can be also seen that the coercivity of SPS sample sintered at 800 degrees C is still high value of 88 Oe, suggesting that the grain growth of magnetic alpha-Fe phase during SPS process tends to be suppressed. PMID:27433621

  1. Performance Evaluation of Sysmex XS-800i Automated Hematology Analyzer%Sysmex XS-800i全自动血细胞分析仪性能评价

    Institute of Scientific and Technical Information of China (English)

    张燕; 夏永泉; 黄爱军

    2008-01-01

    目的:评价Sysmex XS-800i全自动血细胞分析仪的性能.方法:对Sysmex XS-800i的准确性、批内、批间精密度、携带污染率、线性、总重复性进行测定,并取60例健康体检标本同时用Sysmex XS-800i和Sysmex 2100测定WBC、RBC、Hb、PLT4项指标并进行比对.并将这60例标本的Sysmex XS-800i分类结果与手工分类结果进行比较.结果:Sysmex XS-800i的准确性、批内、批间精密度、携带污染率、线性、总重复性均在允许范围内(仪器厂家提供),Sysmex XS-800i和Sysmex 2100对WBC、RBC、Hb、PLT的测定结果据统计学分析无显著性差异(P>0.05),Sysmex XS-800i分类结果与手工分类结果进行比较,相关性较好.结论:Sysmex XS-800i是一种较理想的全自动血细胞分析仪.

  2. Kystmodellen NorKyst-800 – en strømmodell for hele norskekysten

    OpenAIRE

    Asplin, Lars; Sandvik, Anne D.; Albretsen, Jon

    2011-01-01

    Kystmodellen NorKyst-800 er en beregningsmodell som simulerer bl.a. strøm, saltholdighet og temperatur med 800 meters romlig oppløsning og med høy oppløsning i tid for hele norskekysten. NorKyst-800 er utviklet på Havforskningsinstituttet i samarbeid med Meteorologisk institutt og Niva. :: The coastal model NorKyst-800 is a computer model that simulates variables such as currents, salinity and temperature along the whole Norwegian coast, at an 800 metre spatia...

  3. Calibration of UP2 800 accountancy tank; Etalonnage de la cuve de comptabilite de UP2 800 (La Hague)

    Energy Technology Data Exchange (ETDEWEB)

    Cauchetier, Ph.; Roche, C. [CEA Centre d`Etudes de la Vallee du Rhone, 30 - Marcoule (France). Dept. des Procedes de Retraitement; Dufour, J.L. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire; Neuilly, M.; Fournier, P.; Evain, D. [Compagnie Generale des Matieres Nucleaires (COGEMA), 78 - Velizy-Villacoublay (France); Blandeau, L.; Janin, V. [Societe Generale pour les Techniques Nouvelles (SGN), 78 - Saint-Quentin-en-Yvelines (France)

    1993-12-31

    UP2 800 plant, now on building at ``La Hague``, is equipped with an accountability tank of 20 m{sup 3} volume. That tank is used to feed the facility with solution transfers; these transfers are triggered by siphons. This paper describes calibration measures realized with that tank for setting up the curve of volume V versus the level H and for finding the volumes left after clipping of siphons. It presents also the results for the level differences between the end points of bubbling tubes. Results are given, with the corresponding accuracy, in the case of measures with water as solution. Further tests will be made with uranyl nitrate. (authors). 3 refs.

  4. My Opinion on 800- meter Running Teaching%试论800m耐力跑教学方法

    Institute of Scientific and Technical Information of China (English)

    肖建章

    2004-01-01

    针对大学女生800m耐力跑教学中存在的各种问题,进行了教法研究.即注意培养学生正确的学习动机;对耐力跑具有畏惧心理的学生,进行疏通和调节;增加教师对学生的情感投入;采用灵活多样的教学方法,以及跑后的自我测评与放松整理活动.实践证明,该方法取得了较好的教学效果.

  5. Phase stability, deformation mechanisms, and mechanical properties of Nb-Al-Ti alloys

    International Nuclear Information System (INIS)

    The phase stability, deformation mechanisms and mechanical properties of two alloys based on Nb3Al containing additions of Ti have been studied. These two alloys, with nominal compositions (in at.%) of Nb-15Al-10Ti (alloy 1) and Nb-15Al-40Ti (alloy 2), have the B2 crystal structure in as cast form. The ALCHEMI technique has been employed to assess qualitatively the distribution of atom types over the two sublattices of the B2 compounds. It is found that Ti and Al occupy different sublattices in alloy 2. Heat-treatment of alloy 1 at 1,100 C results in the precipitation of an A15 phase in the B2 matrix. Annealing at 900 C for short time introduces an w-phase. Prolonged annealing of alloy 1 at 700 C reveals the presence of an orthorhombic phase. The same orthorhombic phase is also found to exist between 800 and 1,000 C in alloy 2. Specific orientation relationships exist between the matrix phase and precipitates. The yield strength in compression of Alloy 1 and 2 were determined at various temperatures. Alloy 1 is strong compared to superalloy IN 718 over a range of temperatures up to 950 C. Both alloys with the B2 crystal structure are deformed by one or more of the following slip systems, namely (110), (112) and (123). Dislocations with Burgers vector, b, given by b= are present in the form of dissociated superpartial pairs, each with b=1/2. The inherent ductility of both alloys is indicated by the active slip systems and illustrated by 20% elongation to failure obtained in alloy 2 under room temperature tensile test. A trend of increasing tensile yield stress with increasing antiphase domain size was found. No evidence of interaction between dislocations and antiphase boundaries has been found to account for this increase of strength

  6. Effect of pre-oxidation on high temperature sulfidation behavior of FeCr and FeCrAl alloys

    Directory of Open Access Journals (Sweden)

    Pillis Marina Fuser

    2004-01-01

    Full Text Available High temperature corrosion of structural alloys in sulfur bearing environments is many orders of magnitude higher than in oxidizing environments. Efforts to increase sulfidation resistance of these alloys include addition of alloying elements. Aluminum additions to iron-chromium alloys bring about increase in sulfidation resistance. This paper reports the effect of pre-oxidation on the sulfidation behavior of Fe-20Cr and Fe-20Cr-5Al alloys in H2-2% H2S environment at 800 °C. The surfaces of sulfidized specimens were also examined. Pre-oxidation of the two alloys results in an incubation period during subsequent sulfidation. After this incubation period, the Fe-20Cr alloy showed sulfidation behavior similar to that when the alloy was not pre-oxidized. The incubation period during sulfidation of the Fe-20Cr-5Al alloy was significantly longer, over 45 h, compared to 2 h for the Al free alloy. Based on the microscopic and gravimetric data a mechanism for sulfidation of these alloys with pre-oxidation has been proposed.

  7. Effect of thermomechanical processing on evolution of various phases in Ti–Nb alloys

    Indian Academy of Sciences (India)

    S Banumathy; K S Prasad; R K Mandal; A K Singh

    2011-12-01

    This paper deals with the effect of thermomechanical processing on microstructural evolution of three alloys, viz. Ti–8Nb, Ti–12Nb and Ti–16Nb. The alloys were hot rolled at 800°C and then subjected to various heat treatments. Samples from hot-rolled alloys were given solution-treatment in and + phase fields, respectively followed by water quenching and furnace cooling. The solution-treated alloys were subsequently aged at different temperatures for 24 h. Phases evolved after various heat treatments were studied using X-ray diffractometer, optical, scanning and transmission electron microscopes. The alloy Ti–8Nb exhibits and phases while the alloys Ti–12Nb and Ti–16Nb show the presence of '', and phases in the as-cast and hot-rolled conditions. The solution treated and water quenched specimen of the alloy Ti–8Nb displays '' phase while the alloys Ti–12Nb and Ti–16Nb exhibit '', and phases. The alloy Ti–8Nb shows the presence of , and phases while those of Ti–12Nb and Ti–16Nb display the presence of , '', and in + solution treated and water quenched condition. The observation of phase in solution treated condition depends on the cooling rate and the Nb content while in the aged specimens, it is governed by aging temperature as well as the Nb content.

  8. Effect of oxide films on hydrogen permeability of candidate Stirling heater head tube alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schuon, S R; Misencik, J A

    1981-01-01

    High pressure hydrogen has been selected as the working fluid for the developmental automotive Stirling engine. Containment of the working fluid during operation of the engine at high temperatures and at high hydrogen gas pressures is essential for the acceptance of the Stirling engine as an alternative to the internal combustion engine. Most commercial alloys are extremely permeable to pure hydrogen at high temperatures. A program was undertaken at NASA Lewis Research Center (LeRC) to reduce hydrogen permeability in the Stirling engine heater head tubes by doping the hydrogen working fluid with CO or CO/sub 2/. Small additions of these gases were shown to form an oxide on the inside tube wall and thus reduce hydrogen permeability. A study of the effects of dopant concentration, alloy composition, and effects of surface oxides on hydrogen permeability in candidate heater head tube alloys is summarized. Results showed that hydrogen permeability was similar for iron-base alloys (N-155, A286, IN800, 19-9DL, and Nitronic 40), cobalt-base alloys (HS-188) and nickel-base alloys (IN718). In general, the permeability of the alloys decreased with increasing concentration of CO or CO/sub 2/ dopant, with increasing oxide thickness, and decreasing oxide porosity. At high levels of dopants, highly permeable liquid oxides formed on those alloys with greater than 50% Fe content. Furthermore, highly reactive minor alloying elements (Ti, Al, Nb, and La) had a strong influence on reducing hydrogen permeability.

  9. Techniques for Primary Acoustic Thermometry to 800 K

    Science.gov (United States)

    Ripple, D. C.; Defibaugh, D. R.; Moldover, M. R.; Strouse, G. F.

    2003-09-01

    The NIST Primary Acoustic Thermometer will measure the difference between the International Temperature Scale of 1990 and the Kelvin Thermodynamic Scale throughout the range 273 K to 800 K with uncertainties of only a few millikelvins. The acoustic thermometer determines the frequencies of the acoustic resonances of pure argon gas contained within a spherical cavity with uncertainties approaching one part in 106. To achieve this small uncertainty at these elevated temperatures we developed new acoustic transducers and new techniques for the maintenance of gas purity and for temperature control. The new electro-acoustic transducers are based on the capacitance between a flexible silicon wafer and a rigid backing plate. Without the damping usually provided by polymers, mechanical vibrations caused unstable, spurious acoustic signals. We describe our techniques for suppression of these vibrations. Our acoustic thermometer allows the argon to be continuously flushed through the resonator, thereby preventing the build up of hydrogen that evolves from the stainless-steel resonator. We describe how the argon pressure is stabilized while flushing. The argon exiting from the resonator is analyzed with a customized gas chromatograph. Because the acoustic resonator was so large—it has an outer diameter of 20 cm—a sophisticated furnace, based on surrounding the resonator with three concentric aluminum shells, was designed to maintain thermal uniformity and stability of the resonator at a level of 1 mK. We describe the design, modeling, and operational characteristics of the furnace.

  10. First tests of a 800 kJ HTS SMES

    CERN Document Server

    Tixador, Pascal; Badel, Arnaud; Berger, Kévin; Bellin, Boris; Vallier, Jean-Claude; Allais, Arnaud; Bruzek, Christian-Eric; 10.1109/TASC.2008.921319

    2008-01-01

    SMES using high critical temperature superconductors are interesting for high power pulsed sources. Operation at temperatures above 20 K makes cryogenics easier, enhances stability and improves operation as pulsed power source. In the context of a DGA (Delegation Generate pour l'Armement) project, we have designed and constructed a 800 kJ SMES. The coil is wound with Nexans conductors made of Bi-2212 PIT tapes soldered in parallel. The coil consists in 26 superposed simple pancakes wound and bonded on sliced copper plates coated with epoxy. The rated current is 315 A for an energy of 814 kJ. The external diameter of the coil is 814 mm and its height 222 mm. The cooling at 20 K is only performed by conduction from cryocoolers to make cryogenics very friendly and invisible for the SMES users. The cooling down has been successfully carried out and the thermal system works as designed. After a brief description of the SMES design and construction, some tests will be presented. From a current of 244 A, the SMES de...

  11. Corrosion aspects of compatible alloys in molten salt (FLiNaK) medium for Indian MSR program in the temperature range of 550-750 °C using electrochemical techniques

    International Nuclear Information System (INIS)

    Corrosion behaviours of different alloys were evaluated in fluoride eutectic FLiNaK in the temperature range of 550-750 °C under static and dynamic conditions. Electrochemical polarization and impedance techniques were used to estimate corrosion rate. The results showed that the corrosion process was controlled by activation and in some cases by formation of passive layer. In static mode, the corrosion rates followed the order : Inconel 625 > Inconel 617 > Inconel 600 > Incoloy 800 > Ni 220 > Hastelloy N > Incoloy 800HT. In dynamic mode, Hastelloy N and Incoloy 800HT showed better corrosion resistance in comparison to other alloys. (author)

  12. Superplasticity in titanium alloys

    OpenAIRE

    J. Sieniawski; Motyka, M.

    2007-01-01

    Purpose: The paper reports characteristic of superplasticity phenomenon in titanium alloys and possibility of its applications.Design/methodology/approach: The main objective of the paper is to show features of superplastic forming of titanium alloys and current research trends aiming at widespread application of this technology.Findings: In the paper characteristic of selected superplastic titanium alloys was presented. The effect of microstructural parameters on superplasticity was consider...

  13. PLUTONIUM-ZIRCONIUM ALLOYS

    Science.gov (United States)

    Schonfeld, F.W.; Waber, J.T.

    1960-08-30

    A series of nuclear reactor fuel alloys consisting of from about 5 to about 50 at.% zirconium (or higher zirconium alloys such as Zircaloy), balance plutonium, and having the structural composition of a plutonium are described. Zirconium is a satisfactory diluent because it alloys readily with plutonium and has desirable nuclear properties. Additional advantages are corrosion resistance, excellent fabrication propenties, an isotropie structure, and initial softness.

  14. Corrosion resistant amorphous alloys

    International Nuclear Information System (INIS)

    A review of publication data on corrosion resistance of amorphous alloys and the methods of amorphization of surface layers of massive materials (laser treatment, iron implantation, detonation-gas spraying, cathode and ion sputtering, electrodeposition) was made. A study was made on corrosion properties of Fe66Cr11B10Si4 alloy in cast state and after laser irradiation, rendering the surface amorphous as well as the samples of Arenco iron and steel 20 with ion-plasma coatings of Fe-Cr-Ni-Ti alloy. It was established that amorphous coatings posses much higher corrosion resistance as compared to crystalline alloys on the same base

  15. Oxidation behaviour of bulk W-Cr-Ti alloys prepared by mechanical alloying and HIPing

    Energy Technology Data Exchange (ETDEWEB)

    García-Rosales, C., E-mail: cgrosales@ceit.es [CEIT and Tecnun (University of Navarra), E-20018 San Sebastian (Spain); López-Ruiz, P.; Alvarez-Martín, S.; Calvo, A.; Ordás, N. [CEIT and Tecnun (University of Navarra), E-20018 San Sebastian (Spain); Koch, F.; Brinkmann, J. [Max-Planck-Institut für Plasmaphysik (IPP), EURATOM Association, D-85748 Garching (Germany)

    2014-10-15

    Self-passivating tungsten based alloys are expected to provide a major safety advantage compared to pure tungsten when used as first wall armour of future fusion reactors, due to the formation of a protective oxide scale, preventing the formation of volatile and radioactive WO{sub 3} in case of a loss of coolant accident with simultaneous air ingress. In this work results of isothermal oxidations tests at 800 and 1000 °C on bulk alloy WCr12Ti2.5 performed by thermogravimetric analysis (TGA) and by exposure to flowing air in a furnace are presented. In both cases a thin, dense Cr{sub 2}O{sub 3} layer is found at the outer surface, below which a Cr{sub 2}WO{sub 6} scale and Ti{sub 2}CrO{sub 5} layers alternating with WO{sub 3} are formed. The Cr{sub 2}O{sub 3}, Cr{sub 2}WO{sub 6} and Ti{sub 2}CrO{sub 5} scales act as protective barriers against fast inward O{sup 2−} diffusion. The oxidation kinetics seems to be linear for the furnace exposure tests while for the TGA tests at 800 °C the kinetics is first parabolic, transforming into linear after an initial phase. The linear oxidation rates are 2–3 orders of magnitude lower than for pure W.

  16. Advanced ODS FeCrAl alloys for accident-tolerant fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Dryepondt, Sebastien N [ORNL; Unocic, Kinga A [ORNL; Hoelzer, David T [ORNL; Pint, Bruce A [ORNL

    2014-09-01

    ODS FeCrAl alloys are being developed with optimum composition and properties for accident tolerant fuel cladding. Two oxide dispersion strengthened (ODS) Fe-15Cr-5Al+Y2O3 alloys were fabricated by ball milling and extrusion of gas atomized metallic powder mixed with Y2O3 powder. To assess the impact of Mo on the alloy mechanical properties, one alloy contained 1%Mo. The hardness and tensile properties of the two alloys were close and higher than the values reported for fine grain PM2000 alloy. This is likely due to the combination of a very fine grain structure and the presence of nano oxide precipitates. The nano oxide dispersion was however not sufficient to prevent grain boundary sliding at 800 C and the creep properties of the alloys were similar or only slightly superior to fine grain PM2000 alloy. Both alloys formed a protective alumina scale at 1200 C in air and steam and the mass gain curves were similar to curves generated with 12Cr-5Al+Y2O3 (+Hf or Zr) ODS alloys fabricated for a different project. To estimate the maximum temperature limit of use for the two alloys in steam, ramp tests at a rate of 5 C/min were carried out in steam. Like other ODS alloys, the two alloys showed a significant increase of the mas gains at T~ 1380 C compared with ~1480 C for wrought alloys of similar composition. The beneficial effect of Yttrium for wrought FeCrAl does not seem effective for most ODS FeCrAl alloys. Characterization of the hardness of annealed specimens revealed that the microstructure of the two alloys was not stable above 1000 C. Concurrent radiation results suggested that Cr levels <15wt% are desirable and the creep and oxidation results from the 12Cr ODS alloys indicate that a lower Cr, high strength ODS alloy with a higher maximum use temperature could be achieved.

  17. Effect of thermomechanical treatment on the superelasticity of Ti-7.5Nb-4Mo-2Sn biomedical alloy.

    Science.gov (United States)

    Zhang, D C; Tan, C G; Tang, D M; Zhang, Y; Lin, J G; Wen, C E

    2014-11-01

    Effects of thermomechanical treatment on the microstructure and superelasticity of Ti-7.5Nb-4Mo-2Sn biomedical alloy were investigated by using XRD measurement, optical microscope (OM), transmission electron microscope (TEM) and tensile tests. The titanium alloy samples were prepared by annealing at a temperature in the range of 600 to 1000°C after severe cold rolling; and the samples that were annealed at 800°C were further aged at 600 and 700°C. The volume fraction of α phases decreased while that of ω phases increase with increasing annealing temperature. The α→β transformation temperature of the alloy was determined to be between 700 and 800°C. The alloy that was annealed at 700°C exhibited a high level of superelasticity with relatively high first yield stress (σSIM) at room temperature because it contained a fine α phase. A certain amount of ω phases also resulted in an increase in σSIM, leading to an improvement in the superelasticity of the alloys that were annealed at 900 and 1000°C. Aging treatment led to the precipitations of α and ω phases in the alloy after annealing at 800°C; and the volume fraction of α phases decreased while that of ω phases increased with increasing aging temperature. Excellent superelasticity with high recovered strain (εrecoverable) and strain recovery rate (η) were obtained in the aged alloy due to the reinforcement of α and ω phases induced by aging treatment. The alloy annealed at 700°C for 0.5h exhibited the best superelasticity in all the thermomechanically treated alloys due to the strengthening from the subgrain refining and the precipitating of fine α phases.

  18. Interglacials of the last 800,000 years

    Science.gov (United States)

    Past Interglacials Working Group Of Pages

    2016-03-01

    Interglacials, including the present (Holocene) period, are warm, low land ice extent (high sea level), end-members of glacial cycles. Based on a sea level definition, we identify eleven interglacials in the last 800,000 years, a result that is robust to alternative definitions. Data compilations suggest that despite spatial heterogeneity, Marine Isotope Stages (MIS) 5e (last interglacial) and 11c (~400 ka ago) were globally strong (warm), while MIS 13a (~500 ka ago) was cool at many locations. A step change in strength of interglacials at 450 ka is apparent only in atmospheric CO2 and in Antarctic and deep ocean temperature. The onset of an interglacial (glacial termination) seems to require a reducing precession parameter (increasing Northern Hemisphere summer insolation), but this condition alone is insufficient. Terminations involve rapid, nonlinear, reactions of ice volume, CO2, and temperature to external astronomical forcing. The precise timing of events may be modulated by millennial-scale climate change that can lead to a contrasting timing of maximum interglacial intensity in each hemisphere. A variety of temporal trends is observed, such that maxima in the main records are observed either early or late in different interglacials. The end of an interglacial (glacial inception) is a slower process involving a global sequence of changes. Interglacials have been typically 10-30 ka long. The combination of minimal reduction in northern summer insolation over the next few orbital cycles, owing to low eccentricity, and high atmospheric greenhouse gas concentrations implies that the next glacial inception is many tens of millennia in the future.

  19. Les Vikings . . . . Les Scandinaves et l'Europe 800-1200

    DEFF Research Database (Denmark)

    Dansk 1. udgave: Viking og Hvidekrist. Norden og Europa 800-1200, 1992; sm. anden udgave 1993. Svensk udgave: Från Vikingar till Korsfarare, 1992. Tysk udgave: Wikinger Waräger Normannen. Die Skandinavier und Europa 800-1200, 1992. Engelske og amerikanske udgaver i samarbejde med D.M. Wilson: From...... Viking to Crusader. Scandinavia and Europe 800-1200, 1992...

  20. Reiearch and Framethe Characteriscics of 800-meter-race Training%对800米跑训练特点的研究与构思

    Institute of Scientific and Technical Information of China (English)

    李颖

    2004-01-01

    过去只一味强调800米跑训练的运动量,对速度这个关键因素重视不够,致使许多运动员在比赛中屡屡受挫.文章试图通过对800米跑训练进行重新分析和认识,以纠正传统认识的误区.

  1. 体育专业学生800m跑的训练方法探讨%Methods of 800 meters training of sports majors

    Institute of Scientific and Technical Information of China (English)

    周新华; 李勤

    2001-01-01

    通过分析800m跑的生理机制,在教学与训练中改变了以往陈旧的练习方法,采用了重复训练法,使学生800m跑成绩大幅度提高,从而促进了整个田径教学训练水平的提高.

  2. Copper-tantalum alloy

    Science.gov (United States)

    Schmidt, Frederick A.; Verhoeven, John D.; Gibson, Edwin D.

    1986-07-15

    A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

  3. High temperature niobium alloys

    International Nuclear Information System (INIS)

    Niobium alloys are currently being used in various high temperature applications such as rocket propulsion, turbine engines and lighting systems. This paper presents an overview of the various commercial niobium alloys, including basic manufacturing processes, properties and applications. Current activities for new applications include powder metallurgy, coating development and fabrication of advanced porous structures for lithium cooled heat pipes

  4. Thermofluency in zirconium alloys

    International Nuclear Information System (INIS)

    A summary is presented about the theoretical and experimental results obtained at present in thermofluency under radiation in zirconium alloys. The phenomenon of thermofluency is presented in a general form, underlining the thermofluency at high temperature because this phenomenon is similar to the thermofluency under radiation, which ocurrs in zirconium alloys into the operating reactor. (author)

  5. Welding and mechanical properties of cast FAPY (Fe-16 at. % Al-based) alloy slabs

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J.; Howell, C.R.

    1995-08-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10, and iron = 83.71. The cast ingots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot- worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  6. Ultrahigh temperature intermetallic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Brady, M.P.; Zhu, J.H.; Liu, C.T.; Tortorelli, P.F.; Wright, J.L.; Carmichael, C.A.; Walker, L.R. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1997-12-01

    A new family of Cr-Cr{sub 2}X based alloys with fabricability, mechanical properties, and oxidation resistance superior to previously developed Cr-Cr{sub 2}Nb and Cr-Cr{sub 2}Zr based alloys has been identified. The new alloys can be arc-melted/cast without cracking, and exhibit excellent room temperature and high-temperature tensile strengths. Preliminary evaluation of oxidation behavior at 1100 C in air indicates that the new Cr-Cr{sub 2}X based alloys form an adherent chromia-based scale. Under similar conditions, Cr-Cr{sub 2}Nb and Cr-Cr{sub 2}Zr based alloys suffer from extensive scale spallation.

  7. Alloys in energy development

    International Nuclear Information System (INIS)

    The development of new and advanced energy systems often requires the tailoring of new alloys or alloy combinations to meet the novel and often stringent requirements of those systems. Longer life at higher temperatures and stresses in aggressive environments is the most common goal. Alloy theory helps in achieving this goal by suggesting uses of multiphase systems and intermediate phases, where solid solutions were traditionally used. However, the use of materials under non-equilibrium conditions is now quite common - as with rapidly solidified metals - and the application of alloy theory must be modified accordingly. Under certain conditions, as in a reactor core, the rate of approach to equilibrium will be modified; sometimes a quasi-equilibrium is established. Thus an alloy may exhibit enhanced general diffusion at the same time as precipitate particles are being dispersed and solute atoms are being carried to vacancy sinks. We are approaching an understanding of these processes and can begin to model these complex systems

  8. Characterization of oxide films on Incoloy-800, AISI-304 and Monel-400 in ethanolamine by impedance and ESCA techniques

    International Nuclear Information System (INIS)

    The All Volatile Treatment (AVT), using amines, is practiced in the Steam Generator (SG) circuits of Indian Pressurized Heavy Water Reactors (PHWRs) to maintain the pH in the alkaline condition and provide corrosion protection to the structural materials. The extent of corrosion protection is known to depend on the nature of the material, the chemical composition and stability of the surface oxide films formed in the high temperature alkaline conditions. In this context, it is also important to know the type and defect density (n or p type) of the semi-conducting oxide films which will throw light not only on the film's protective nature but also on the composition of the chemical cleaning formulation required for dissolving the steam generator deposits. Since, ethanolamine (ETA) is being used currently as a pH additive in place of morpholine/ammonia due to the beneficial effects of the former, in most of the reactors, a study was undertaken to characterise the films formed on Incoloy-800, Monel-400 and AISI-304 materials with ETA under secondary water chemistry conditions. The coupons of these materials were exposed to 6 ppm of ethanolamine (pH: ∼9.5) in high temperature autoclave at a temperature of 240 deg C for 10 days and the films were characterized by Electrochemical Impedance Spectroscopy, Mott-Schottky and electron spectroscopy for chemical analysis (ESCA) techniques. The impedance analysis showed that the corrosion resistance followed the order: AISI-304 > Incoloy-800 > Monel-400 and the data mostly fitted well to a porous model equivalent circuit. Defect density calculations, made using the capacitance data, showed that Incoloy and Stainless steel had minimum n-type defect densities whereas Monel, a maximum number. The chemical analyses of the surface films on the alloys by ESCA showed that the films were composed of Ni as the dominating element along with Cr, Fe and O. Ni was seen to be around 22-25 at% in the oxides on the alloys. The chemical

  9. The Effect of Cold Work on Properties of Alloy 617

    Energy Technology Data Exchange (ETDEWEB)

    Richard Wright

    2014-08-01

    Alloy 617 is approved for non-nuclear construction in the ASME Boiler and Pressure Vessel Code Section I and Section VIII, but is not currently qualified for nuclear use in ASME Code Section III. A draft Code Case was submitted in 1992 to qualify the alloy for nuclear service but efforts were stopped before the approval process was completed.1 Renewed interest in high temperature nuclear reactors has resulted in a new effort to qualify Alloy 617 for use in nuclear pressure vessels. The mechanical and physical properties of Alloy 617 were extensively characterized for the VHTR programs in the 1980’s and incorporated into the 1992 draft Code Case. Recently, the properties of modern heats of the alloy that incorporate an additional processing step, electro-slag re-melting, have been characterized both to confirm that the properties of contemporary material are consistent with those in the historical record and to increase the available database. A number of potential issues that were identified as requiring further consideration prior to the withdrawal of the 1992 Code Case are also being re-examined in the current R&D program. Code Cases are again being developed to allow use of Alloy 617 for nuclear design within the rules of the ASME Boiler and Pressure Vessel Code. In general the Code defines two temperature ranges for nuclear design with austenitic and nickel based alloys. Below 427°C (800°F) time dependent behavior is not considered, while above this temperature creep and creep-fatigue are considered to be the dominant life-limiting deformation modes. There is a corresponding differentiation in the treatment of the potential for effects associated with cold work. Below 427°C the principal issue is the relationship between the level of cold work and the propensity for stress corrosion cracking and above that temperature the primary concern is the impact of cold work on creep-rupture behavior.

  10. Verification of Allowable Stresses In ASME Section III Subsection NH For Grade 91 Steel & Alloy 800H

    Energy Technology Data Exchange (ETDEWEB)

    R. W. Swindeman; M. J. Swindeman; B. W. Roberts; B. E. Thurgood; D. L. Marriott

    2007-11-30

    The database for the creep-rupture of 9Cr-1Mo-V (Grade 91) steel was collected and reviewed to determine if it met the needs for recommending time-dependent strength values, S{sub t}, for coverage in ASME Section III Subsection NH (ASME III-NH) to 650 C (1200 F) and 600,000 hours. The accumulated database included over 300 tests for 1% total strain, nearly 400 tests for tertiary creep, and nearly 1700 tests to rupture. Procedures for analyzing creep and rupture data for ASME III-NH were reviewed and compared to the procedures used to develop the current allowable stress values for Gr 91 for ASME II-D. The criteria in ASME III-NH for estimating S{sub t} included the average strength for 1% total strain for times to 600,000 hours, 80% of the minimum strength for tertiary creep for times to 600,000 hours, and 67% of the minimum rupture strength values for times to 600,000 hours. Time-temperature-stress parametric formulations were selected to correlate the data and make predictions of the long-time strength. It was found that the stress corresponding to 1% total strain and the initiation of tertiary creep were not the controlling criteria over the temperature-time range of concern. It was found that small adjustments to the current values in III-NH could be introduced but that the existing values were conservative and could be retained. The existing database was found to be adequate to extend the coverage to 600,000 hours for temperatures below 650 C (1200 F).

  11. Microstructural Changes on Tensile Property of Austenitic Alloys Exposed to High Temperature Supercritical-CO{sub 2} Environment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunmyung; Lee, Ho Jung; Jang, Changheui [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-10-15

    Several studies have been conducted on corrosion and mechanical properties of ferritic martensitic steels (FMSs) in liquid sodium coolant environments. As candidate materials for S-CO{sub 2} intermediate heat exchanger (IHX), corrosion study on tensile property for long-term integrity of austenitic alloys is in great demand. Therefore, in this study, corrosion behavior on tensile property of austenitic alloys after exposure to high temperature S-CO{sub 2} is presented. Microstructural changes are related to the changes in tensile property. The following conclusions can be drawn from this study of corrosion behavior on tensile property of austenitic alloys after exposure to high temperature S-CO{sub 2}: 1. Both Fe-base and Ni-base austenitic alloys showed a good corrosion resistance at 550 .deg. C, whereas at higher temperatures (over 600.deg.C) the corrosion characteristics of the Fe-base alloys were severely worsened compared to the Ni-base. 2. Changes in tensile property seemed to have no effects of base elements. Rather, SS 316H, Alloy 625 and 800HT - showed a reduced ductility at over 600 .deg.C regardless of their base elements. 3. SS 316H showed grain boundary precipitates while a large quantity of precipitates were found within/along the grain boundary for Alloy 625 and 800HT after ageing at higher temperatures.

  12. Microstructure Refinement of Sn-Sb Peritectic Alloy under High-Intensity Ultrasound Treatment

    Institute of Scientific and Technical Information of China (English)

    戚飞鹏; 张海波; 高守雷; 翟启杰

    2005-01-01

    In this paper the solidification behavior of Sn-Sb peritectic alloy and the mechanism of grain refinement in solidification process under high-intensity ultrasonic field are investigated. Three different powers of high-intensity ultrasound are introduced into molten Sn-Sb peritectic alloy to study the refining effectiveness. The results show that the application of high-intensity ultrasound during solidification process of Sn-Sb peritectic alloy can refine a phase and β phase and eliminate gravity segregation of the alloy. As acoustic intensity is increased from 400 W to 800 W, not only the homogenous fine structure can be obtained, but also the cubic β phase crystals tend to be spherical. Microstructure of the sample treated by 600 W high-intensity ultrasound demonstrates the best refining effect.

  13. Investigation of austenitic alloys for advanced heat recovery and hot-gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    Materials properties were collected for the design and construction of structural components for use in advanced heat recovery and hot gas cleanup systems. Alloys systems included 9Cr-1Mo-V steel, modified 316 stainless steel, modified type 310 stainless steel, modified 20Cr-25Ni-Nb stainless steel, and modified alloy 800. Experimental work was undertaken to expand the databases for potentially useful alloys. Types of testing included creep, stress-rupture, creep-crack growth, fatigue, and post-exposure short-time tensile tests. Because of the interest in relatively inexpensive alloys for service at 700 C and higher, research emphasis was placed on a modified type 310 stainless steel and a modified 20Cr-25Ni-Nb stainless steel. Both steels were found to have useful strength to 925 C with good weldability and ductility.

  14. 34 CFR 85.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false What are the causes for debarment? 85.800 Section 85... (NONPROCUREMENT) Debarment § 85.800 What are the causes for debarment? We may debar a person for— (a) Conviction... causes: (1) A nonprocurement debarment by any Federal agency taken before October 1, 1988, or...

  15. 29 CFR 1471.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false What are the causes for debarment? 1471.800 Section 1471... GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 1471.800 What are the causes for debarment... agreement or transaction; (c) Any of the following causes: (1) A nonprocurement debarment by any...

  16. 2 CFR 180.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false What are the causes for debarment? 180.800... (NONPROCUREMENT) Debarment § 180.800 What are the causes for debarment? A Federal agency may debar a person for... or transaction; (c) Any of the following causes: (1) A nonprocurement debarment by any Federal...

  17. International standard on auditing 800 the auditor`s report on special purpose audit engagements

    OpenAIRE

    JOVANOVA, Blagica

    2011-01-01

    The purpose of this report is to show the main characteristics of the international standard on auditing 800. ISA 800 explains requirements by making a report on financial statements prepared in accordance with another comprehensive basis of accounting, on a component of financial statements, on compliance with contractual agreements or reports on summarized financial statements.

  18. 75 FR 45130 - Draft Compliance Policy Guide Sec. 690.800 Salmonella

    Science.gov (United States)

    2010-08-02

    ... HUMAN SERVICES Food and Drug Administration Draft Compliance Policy Guide Sec. 690.800 Salmonella in... entitled ``Compliance Policy Guide Sec. 690.800 Salmonella in Animal Feed'' (the draft CPG). The draft CPG..., contaminated with Salmonella and also on regulatory policy relating to animal feed or feed...

  19. 13 CFR 120.800 - The purpose of the 504 program.

    Science.gov (United States)

    2010-01-01

    ..., and stimulate growth, expansion, and modernization of small businesses. ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false The purpose of the 504 program. 120.800 Section 120.800 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS...

  20. 34 CFR 682.800 - Prohibition against discrimination as a condition for receiving special allowance payments.

    Science.gov (United States)

    2010-07-01

    ... receiving special allowance payments. 682.800 Section 682.800 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM Special Allowance Payments on Loans Made or Purchased With Proceeds of...

  1. 13 CFR 126.800 - Who may protest the status of a qualified HUBZone SBC?

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Who may protest the status of a qualified HUBZone SBC? 126.800 Section 126.800 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION... apparent successful offeror's qualified HUBZone SBC status....

  2. 7 CFR 800.152 - Maintenance and retention of file samples.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Maintenance and retention of file samples. 800.152... REGULATIONS Official Records and Forms (general) § 800.152 Maintenance and retention of file samples. (a... retention period. (1) Trucks In 3 Out 5 (2) Railcars In 5 Out 10 (3) Barges (river) In 5 Out 25 (4)...

  3. The phase system Fe-Ir-S at 1100, 1000 and 800 degree C

    DEFF Research Database (Denmark)

    Makovicky, Emil; Karup-Møller, Sven

    1999-01-01

    Phase relations in the dry condensed Fe-Ir-S system were determined at 1100, 1000 and 800 degrees C. Orientational runs were performed at 500 degrees C. Between 1100 and 800 degrees C, the system comprises five sulphides and an uninterrupted field of gamma(Fe, Ir). Fe1-xS dissolves 5.8 at.% Ir...

  4. On the oxide formation on stainless steels AISI 304 and incoloy 800H investigated with XPS

    NARCIS (Netherlands)

    Langevoort, J.C.; Sutherland, I.; Hanekamp, L.J.; Gellings, P.J.

    1987-01-01

    The influence of cold work on the initially formed oxide layer on the stainless steels AISI 304 and Incology 800H has been studied by XPS. Oxidations were performed at pressures of 10-6-10-4 Pa and temperatures of 300–800 K. All samples showed a similar oxidation behaviour. The oxidation rates of ir

  5. 30 CFR 75.800 - High-voltage circuits; circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 75.800... § 75.800 High-voltage circuits; circuit breakers. High-voltage circuits entering the underground area of any coal mine shall be protected by suitable circuit breakers of adequate interrupting...

  6. 30 CFR 77.800 - High-voltage circuits; circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 77.800... COAL MINES Surface High-Voltage Distribution § 77.800 High-voltage circuits; circuit breakers. High-voltage circuits supplying power to portable or mobile equipment shall be protected by suitable...

  7. Nanostructures obtained from a mechanically alloyed and heat treated molybdenum carbide

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Barriga Arceo, L. [Programa de Ingenieria Molecular, I.M.P. Lazaro Cardenas 152, C.P. 07730 D.F. Mexico (Mexico) and ESIQIE-UPALM, IPN Apdo Postal 118-395, C.P. 07051 D.F. Mexico (Mexico)]. E-mail: luchell@yahoo.com; Orozco, E. [Instituto de Fisica UNAM, Apdo Postal 20-364, C.P. 01000 D.F. Mexico (Mexico)]. E-mail: eorozco@fisica.unam.mx; Mendoza-Leon, H. [ESIQIE-UPALM, IPN Apdo Postal 118-395, C.P. 07051 D.F. Mexico (Mexico)]. E-mail: luchell@yahoo.com; Palacios Gonzalez, E. [Programa de Ingenieria Molecular, I.M.P. Lazaro Cardenas 152, C.P. 07730 D.F. Mexico (Mexico)]. E-mail: epalacio@imp.mx; Leyte Guerrero, F. [Programa de Ingenieria Molecular, I.M.P. Lazaro Cardenas 152, C.P. 07730 D.F. Mexico (Mexico)]. E-mail: fleyte@imp.mx; Garibay Febles, V. [Programa de Ingenieria Molecular, I.M.P. Lazaro Cardenas 152, C.P. 07730 D.F. Mexico (Mexico)]. E-mail: vgaribay@imp.mx

    2007-05-31

    Mechanical alloying was used to prepare molybdenum carbide. Microstructural characterization of samples was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. Molybdenum carbide was heated at 800 {sup o}C for 15 min in order to produce carbon nanotubes. Nanoparticles of about 50-140 nm in diameter and nanotubes with diameters of about 70-260 nm and 0.18-0.3 {mu}m in length were obtained after heating at 800 {sup o}C, by means of this process.

  8. Basic principles of creating a new generation of high- temperature brazing filler alloys

    Science.gov (United States)

    Kalin, B. A.; Suchkov, A. N.

    2016-04-01

    The development of new materials is based on the formation of a structural-phase state providing the desired properties by selecting the base and the complex of alloying elements. The development of amorphous filler alloys for a high-temperature brazing has its own features that are due to the limited life cycle and the production method of brazing filler alloys. The work presents a cycle of analytical and experimental materials science investigations including justification of the composition of a new amorphous filler alloy for brazing the products from zirconium alloys at the temperature of no more than 800 °C and at the unbrazing temperature of permanent joints of more than 1200 °C. The experimental alloys have been used for manufacture of amorphous ribbons by rapid quenching, of which the certification has been made by X-ray investigations and a differential-thermal analysis. These ribbons were used to obtain permanent joints from the spacer grid cells (made from the alloy Zr-1% Nb) of fuel assemblies of the thermal nuclear reactor VVER-440. The brazed samples in the form of a pair of cells have been exposed to corrosion tests in autoclaves in superheated water at a temperature of 350 °C, a pressure of 160 MPa and duration of up to 6,000 h. They have been also exposed to destructive tests using a tensile machine. The experimental results obtained have made it possible to propose and patent a brazing filler alloy of the following composition: Zr-5.5Fe-(2.5-3.5)Be-1Nb-(5-8)Cu-2Sn-0.4Cr-(0.5-1.0)Ge. Its melting point is 780 °C and the recommended brazing temperature is 800°C.

  9. Bone bonding strength of diamond-structured porous titanium-alloy implants manufactured using the electron beam-melting technique.

    Science.gov (United States)

    Hara, Daisuke; Nakashima, Yasuharu; Sato, Taishi; Hirata, Masanobu; Kanazawa, Masayuki; Kohno, Yusuke; Yoshimoto, Kensei; Yoshihara, Yusuke; Nakamura, Akihiro; Nakao, Yumiko; Iwamoto, Yukihide

    2016-02-01

    The present study examined the bone bonding strength of diamond-structured porous titanium-alloy (Porous-Ti-alloy) manufactured using the electron beam-melting technique in comparison with fiber mesh-coated or rough-surfaced implants. Cylindrical implants with four different pore sizes (500, 640, 800, and 1000μm) of Porous-Ti-alloy, titanium fiber mesh (FM), and surfaces roughened by titanium arc spray (Ti-spray) were implanted into the distal femur of rabbits. Bone bonding strength and histological bone ingrowth were evaluated at 4 and 12weeks after implantation. The bone bonding strength of Porous-Ti-alloy implants (640μm pore size) increased over time from 541.4N at 4weeks to 704.6N at 12weeks and was comparable to that of FM and Ti-spray implants at both weeks. No breakage of the porous structure after mechanical testing was found with Porous-Ti-alloy implants. Histological bone ingrowth that increased with implantation time occurred along the inner structure of Porous-Ti-alloy implants. There was no difference in bone ingrowth in Porous-Ti-alloy implants with pore sizes among 500, 640, and 800μm; however, less bone ingrowth was observed with the 1000μm pore size. These results indicated Porous-Ti-alloy implants with pore size under 800μm provided biologically active and mechanically stable surface for implant fixation to bone, and had potential advantages for weight bearing orthopedic implants such as acetabular cups.

  10. Effect of thermomechanical treatment on the superelasticity of Ti–7.5Nb–4Mo–2Sn biomedical alloy

    International Nuclear Information System (INIS)

    Effects of thermomechanical treatment on the microstructure and superelasticity of Ti–7.5Nb–4Mo–2Sn biomedical alloy were investigated by using XRD measurement, optical microscope (OM), transmission electron microscope (TEM) and tensile tests. The titanium alloy samples were prepared by annealing at a temperature in the range of 600 to 1000 °C after severe cold rolling; and the samples that were annealed at 800 °C were further aged at 600 and 700 °C. The volume fraction of α phases decreased while that of ω phases increase with increasing annealing temperature. The α → β transformation temperature of the alloy was determined to be between 700 and 800 °C. The alloy that was annealed at 700 °C exhibited a high level of superelasticity with relatively high first yield stress (σSIM) at room temperature because it contained a fine α phase. A certain amount of ω phases also resulted in an increase in σSIM, leading to an improvement in the superelasticity of the alloys that were annealed at 900 and 1000 °C. Aging treatment led to the precipitations of α and ω phases in the alloy after annealing at 800 °C; and the volume fraction of α phases decreased while that of ω phases increased with increasing aging temperature. Excellent superelasticity with high recovered strain (εrecoverable) and strain recovery rate (η) were obtained in the aged alloy due to the reinforcement of α and ω phases induced by aging treatment. The alloy annealed at 700 °C for 0.5 h exhibited the best superelasticity in all the thermomechanically treated alloys due to the strengthening from the subgrain refining and the precipitating of fine α phases. - Highlights: • α → β transformation temperature of Ti–7.5Nb–4Mo–2Sn alloy is between 700 and 800 °C. • A certain amount of ω phases leads to the improvement in the superelasticity (SE). • The alloy annealed at 700 °C shows excellent SE due to fine α phases contained. • The precipitation of α and

  11. Effect of thermomechanical treatment on the superelasticity of Ti–7.5Nb–4Mo–2Sn biomedical alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, D.C.; Tan, C.G.; Tang, D.M.; Zhang, Y. [Faculty of Material and Optical-electronic Physics, Key Laboratory of Low Dimensional Materials and Application Technology (Ministry of Education), Xiangtan University, Xiangtan, 411105 Hunan (China); Lin, J.G., E-mail: lin_j_g@xtu.edu.cn [Faculty of Material and Optical-electronic Physics, Key Laboratory of Low Dimensional Materials and Application Technology (Ministry of Education), Xiangtan University, Xiangtan, 411105 Hunan (China); Wen, C.E. [Faculty of Engineering and Industrial Science, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia)

    2014-11-01

    Effects of thermomechanical treatment on the microstructure and superelasticity of Ti–7.5Nb–4Mo–2Sn biomedical alloy were investigated by using XRD measurement, optical microscope (OM), transmission electron microscope (TEM) and tensile tests. The titanium alloy samples were prepared by annealing at a temperature in the range of 600 to 1000 °C after severe cold rolling; and the samples that were annealed at 800 °C were further aged at 600 and 700 °C. The volume fraction of α phases decreased while that of ω phases increase with increasing annealing temperature. The α → β transformation temperature of the alloy was determined to be between 700 and 800 °C. The alloy that was annealed at 700 °C exhibited a high level of superelasticity with relatively high first yield stress (σ{sub SIM}) at room temperature because it contained a fine α phase. A certain amount of ω phases also resulted in an increase in σ{sub SIM}, leading to an improvement in the superelasticity of the alloys that were annealed at 900 and 1000 °C. Aging treatment led to the precipitations of α and ω phases in the alloy after annealing at 800 °C; and the volume fraction of α phases decreased while that of ω phases increased with increasing aging temperature. Excellent superelasticity with high recovered strain (ε{sub recoverable}) and strain recovery rate (η) were obtained in the aged alloy due to the reinforcement of α and ω phases induced by aging treatment. The alloy annealed at 700 °C for 0.5 h exhibited the best superelasticity in all the thermomechanically treated alloys due to the strengthening from the subgrain refining and the precipitating of fine α phases. - Highlights: • α → β transformation temperature of Ti–7.5Nb–4Mo–2Sn alloy is between 700 and 800 °C. • A certain amount of ω phases leads to the improvement in the superelasticity (SE). • The alloy annealed at 700 °C shows excellent SE due to fine α phases contained. • The

  12. Effect of heat treatment on the physical properties of Ni-Mn-Ga alloy

    Energy Technology Data Exchange (ETDEWEB)

    Koek, Mediha, E-mail: msoglu@firat.edu.tr [Firat University, Sciences Faculty, Department of Physics Elazig (Turkey); Aydogdu, Y Latin-Small-Letter-Dotless-I ld Latin-Small-Letter-Dotless-I r Latin-Small-Letter-Dotless-I m, E-mail: y.aydogdu@gazi.edu.tr [Superconductivity and Thermal Analysis Laboratory, Department of Physics, Faculty of Science, Gazi University, Ankara (Turkey)

    2012-11-20

    Highlights: Black-Right-Pointing-Pointer Heat treatment on the physical properties of Ni{sub 50.5}Mn{sub 29.5}Ga{sub 20} alloys was investigated. Black-Right-Pointing-Pointer The heat treatments were conducted at 800 Degree-Sign C, 900 Degree-Sign C, and 1000 Degree-Sign C for 2 h in argon atmosphere. Black-Right-Pointing-Pointer Heat treatment emerged as a new phase, which improves ductility. Black-Right-Pointing-Pointer Heat treatment changed the thermal properties of NiMnGa alloys. - Abstract: In this study, the effect of heat treatment on physical properties such as crystal structure, transformation temperatures, thermodynamic behavior and activation energy of Ni{sub 50.5}Mn{sub 29.5}Ga{sub 20} (at.%) off-stoichiometric Heusler alloys was investigated. The heat treatments were conducted at 800 Degree-Sign C, 900 Degree-Sign C and 1000 Degree-Sign C for 2 h in argon atmosphere and then samples were quenched in ice brine. It has been found that the heat treated alloys possess a coexistence phase of martensite and gamma ({gamma}) phases while the untreated alloy is {gamma} phase free. Moreover, elevating the annealing temperature resulted in increased martensitic transformation temperatures.

  13. Standard Specification for Copper-Aluminum-Silicon-Cobalt Alloy, Copper-Nickel-Silicon-Magnesium Alloy, Copper-Nickel-Silicon Alloy, Copper-Nickel-Aluminum-Magnesium Alloy, and Copper-Nickel-Tin Alloy Sheet and Strip

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2015-01-01

    Standard Specification for Copper-Aluminum-Silicon-Cobalt Alloy, Copper-Nickel-Silicon-Magnesium Alloy, Copper-Nickel-Silicon Alloy, Copper-Nickel-Aluminum-Magnesium Alloy, and Copper-Nickel-Tin Alloy Sheet and Strip

  14. An Oxidation-Resistant Coating Alloy for Gamma Titanium Aluminides

    Science.gov (United States)

    Brady, Michael P.; Smialek, James L.; Brindley, William J.

    1997-01-01

    Titanium aluminides based on the g-phase (TiAl) offer the potential for component weight savings of up to 50 percent over conventional superalloys in 600 to 850 C aerospace applications. Extensive development efforts over the past 10 years have led to the identification of "engineering" gamma-alloys, which offer a balance of room-temperature mechanical properties and high-temperature strength retention. The gamma class of titanium aluminides also offers oxidation and interstitial (oxygen and nitrogen) embrittlement resistance superior to that of the alpha(sub 2) (Ti3Al) and orthorhombic (Ti2AlNb) classes of titanium aluminides. However, environmental durability is still a concern, especially at temperatures above 750 to 800 C. Recent work at the NASA Lewis Research Center led to the development of an oxidation-resistant coating alloy that shows great promise for the protection of gamma titanium aluminides.

  15. High Temperature Oxidation and Electrochemical Investigations on Ni-base Alloys

    OpenAIRE

    Obigodi-Ndjeng, Marthe Georgia

    2011-01-01

    This study examined high-temperature oxidation behavior of different Ni-base alloys. In addition, electrochemical characterization of the alloy’s corrosion behavior was carried out, including comparison of the properties of native passive films grown at room temperature and high temperature oxide scales. PWA 1483 (single-crystalline Ni-base superalloy) and model alloys Ni-Cr-X (where X is either Co or Al) were oxidized at 800 and 900 °C in air for different time periods. The superalloy showed...

  16. ′ Precipitation and Growth Kinetics in Mechanically Alloyed Ni–Al

    OpenAIRE

    Tang, Qingxin; Ukai, Shigeharu; Minami, Akinobu; Hayashi, Shigenari

    2011-01-01

    The precipitation and growth kinetics of γ′ precipitates, which are strengthening factors in Ni-base oxide dispersion strengthened (ODS) superalloys, were investigated. The cuboidal-type γ′ precipitates are formed in conventional arc-melted Ni–Al alloys, whereas spherical-type precipitates are formed in the mechanically alloyed (MAed) specimens. The morphology is controlled by a lattice misfit between the γ′ precipitates and the matrix at the aging temperature of 800°C. The growth kinetics of...

  17. Structure of Sm-Co-Cu-Fe-Zr alloys for permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Linetskij, Ya.L.; Savich, A.N.; Knizhnik, E.G.; Menushenkova, N.V.; Polunin, V.V.; Korovyatskaya, M.V. (Moskovskij Inst. Stali i Splavov (USSR))

    1982-02-01

    Structure changes in the 25 Sm - 50 Co - (10-15) Fe - (8-12) Cu - 2 Zr alloys during their processing for the state with high magnetic properties are investigated by means of optical, electron microscopy and X-ray diffraction analysis. Dendrite non-uniformity is removed during the alloy sintering and the Th/sub 2/Zn/sub 17/ type phase turns to be the basic structural constituent. Tempering at 800 deg C results in transformation of solid solution in the result of which canted cellular and banded structures are formed.

  18. Loss of coherency of the alpha/beta interface boundary in titanium alloys during deformation

    Science.gov (United States)

    Zherebtsov, Sergey; Salishchev, Gennady; Semiatin, S. Lee

    2010-12-01

    The loss of coherency of interphase boundaries in two-phase titanium alloys during deformation was analyzed. The energy of the undeformed interphase boundary was first determined by means of the van der Merwe model for stepped interfaces. The subsequent loss of coherency was ascribed to the increase of interphase energy due to absorption of lattice dislocations and was quantified by a relation similar to the Read-Shockley equation for low-angle boundaries in single-phase alloys. It was found that interphase boundaries lose their coherency by a strain of approximately 0.5 at T = 800°C.

  19. Preparation of nanometer FeCuP alloy and its application in decomposition of PH3

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new ternary Fe-based alloy catalyst FeCuP applied to decompose PH3 was prepared with low-cost material by chemical reduction deposition method. The properties of it were characterized by XRD, ICP and SEM. Its catalytic activity on the decomposition of PH3 and the decomposition conditions were studied. FeCuP alloy exhibits high thermal stabilities and high catalytic activity. Using it as catalyst, the decomposition temperature of phosphine decreases from over 800 ℃ to 400-500 ℃. The decomposition rate of phosphine achieved 100%.

  20. Growth and characterization of uranium–zirconium alloy thin films for nuclear industry applications

    International Nuclear Information System (INIS)

    Polycrystalline and epitaxial U–Zr thin films have been grown on glass and single-crystal sapphire substrates using ultra-high vacuum magnetron sputtering at high temperatures (T = 800 °C). Mixed α- and γ-U phases were detected for polycrystalline U–Zr alloy thin films with the prevailing crystal structure controlled by composition. Epitaxial U–Zr thin film samples were determined to form bi-layered structures of single-crystal γ-U and α-U phases or γ-U, δ UZr2 and α-U phases depending on the concentration of the alloying element. (paper)

  1. Refractory alloy component fabrication

    International Nuclear Information System (INIS)

    Purpose of this report is to describe joining procedures, primarily welding techniques, which were developed to construct reliable refractory alloy components and systems for advanced space power systems. Two systems, the Nb-1Zr Brayton Cycle Heat Receiver and the T-111 Alloy Potassium Boiler Development Program, are used to illustrate typical systems and components. Particular emphasis is given to specific problems which were eliminated during the development efforts. Finally, some thoughts on application of more recent joining technology are presented. 78 figures

  2. Machining of titanium alloys

    CERN Document Server

    2014-01-01

    This book presents a collection of examples illustrating the resent research advances in the machining of titanium alloys. These materials have excellent strength and fracture toughness as well as low density and good corrosion resistance; however, machinability is still poor due to their low thermal conductivity and high chemical reactivity with cutting tool materials. This book presents solutions to enhance machinability in titanium-based alloys and serves as a useful reference to professionals and researchers in aerospace, automotive and biomedical fields.

  3. Determination of composition and fluidity of an alloy for impregnating hard alloys on the basis of titanium carbide

    Directory of Open Access Journals (Sweden)

    A. Z. Issagulov

    2016-07-01

    Full Text Available In this paper optimum compositions of a metal bond of Cr – Ni - Co system are determined by mathematical planning methods. As a response function, value of bending strength at a temperature of 800 °C was used. On the basis of the developed planning matrix samples of required composition were made, bending strength and long-term strength are measured. A certain composition of alloy-bond and its quantity is found. Spiral tests were conducted to determine fluidity.

  4. Heavy Hyperfragments produced by 800 MeV/c k in Nuclear Emulsions; Hiperfragmentos pesados producidos por K de 800 MeV c en emulsiones nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Marcial, P.

    1967-07-01

    A statistical and phenomenological survey of nearly 1200 heavy hyperfragments produced by interaction of 800 MeV/c K with the heavy nuclei of llford K{sub 5} emulsion is presented. The emulsion was exposed A statistical and phenomenological survey of nearly 1200 heavy hyperfragments produced by interaction of 800 MeV/c K with the heavy nuclei of llford K5 emulsion is presented. The emulsion was exposed in Berkeley. The variation of long list of parameters dealing with both the production and desintegration of the hyperfragments, with the size of the primary interaction is given. (Author)

  5. Performance Evaluation of Sysmex XS-800i Automated Hematology Analyzer%Sysmex XS-800i全自动血细胞分析仪性能评价

    Institute of Scientific and Technical Information of China (English)

    易勤

    2012-01-01

    目的 评价Sysmex XS-800i全自动血细胞分析仪的性能.方法 对Sysmex XS-800i的准确性、批内及批间精密度、携带污染率、稀释效果、总重复性、白细胞分类检测的重复性进行测定,并取20例健康体检和病人标本同时用Sysmex XS-800i和Sysmex XT-1800i测定WBC、RBC、Hb、PLT、HCT五项指标并进行比对,并从中随机抽取5个健康体检标本的Sysmex XS-800i分类结果与手工分类结果进行比较.结果 Sysmex XS-800i的准确性、批内及批间精密度、携带污染率、稀释效果、总重复性均在允许范围内,Sysmex XS-800i和Sysmex XT-1800i对WBC、RBC、Hb、PLT、HCT的测定结果经统计学分析无显著性差异(P>0.90),Sysmex XS-800i分类结果与手工分类结果进行比较,相关性较好.结论 Sysmex XS-800i是一种较理想的全自动血细胞分析仪,性能良好,检测结果与显微镜目测有良好的一致性;检测快速、准确、重复性好,可用于医院实验室对批量全血标本血细胞分析进行有效的筛选.

  6. Characterization and corrosion study of NiTi laser surface alloyed with Nb or Co

    Science.gov (United States)

    Ng, K. W.; Man, H. C.; Yue, T. M.

    2011-02-01

    The interest in NiTi alloys for medical applications has been steadily growing in recent years because of its biocompatibility, superelasticity and shape memory characteristics. However, the high Ni content in NiTi alloys is still a concern for its long-term applications in the human body. The release of Ni ion into the human body might cause serious problems, as Ni is capable of eliciting toxic and allergic responses. In view of this, surface modification to reduce the surface content of Ni and to improve the corrosion resistance, both of which would reduce Ni release, is an important step in the development of NiTi implants. In the present study, NiTi was surface alloyed with Nb or Co by laser processing. The fine dendritic structure characteristic of laser processing has been described in terms of rapid solidification. The amount of surface elemental Ni was reduced to 10% and 35% for the Nb-alloyed and Co-alloyed layer, respectively. The corrosion resistance in Hanks' solution (a simulated body fluid) was increased as evidenced by a reduced passive current density and a higher pitting potential for both the Nb- and Co-alloyed specimens. The composition and hardness profiles along the depth of the modified layer were correlated with the distribution of the dendrites. The microhardness of the alloyed layers was around 700-800 Hv, which was about four times that of the untreated NiTi specimens.

  7. High-temperature shape memory alloys based on the RuNb system

    International Nuclear Information System (INIS)

    Many applications of shape memory alloys (SMAs) require the development of alloys with high martensitic transformation (MT) temperatures. Among the different systems for high temperature SMAs, equiatomic RuNb alloys demonstrate both shape memory effect (SME) and MT temperatures above 800 deg. C. This work investigates Ru50-xNb50+x (at.%) alloys and shows that Nb content significantly affects the MT behavior. Alloys near the equiatomic composition (x = 0, 2, 4) undergo two displacive transformations on cooling: β (B2) → β' (body centered tetragonal) → β'' (monoclinic). The Ru45Nb55 alloy exhibits a single transition from cubic to tetragonal on cooling. This MT gives rise to a highly twinned microstructure with a (0 1 1) compound-twinning mode and is considered to be responsible for the SME in both types of alloys. The reorientation of martensite variants during deformation has been confirmed through scanning electron microscopy of compression specimens. A promising shape memory behavior is obtained through three-point bend tests performed both in the β' and β'' phases

  8. Wetting and sealing of interface between 7056 Glass and Kovar alloy

    International Nuclear Information System (INIS)

    This study examines the wetting and sealing of Kovar alloy with 7056 Glass. First, the Kovar alloy underwent pre-oxidization treatment at three different temperatures (700, 800 and 900 deg. C) and for seven different isothermal holding periods (0, 3, 5, 10, 15, 30 and 60 min), producing oxide layers of different thickness on the surface of the alloy. Then the wetting experiment was conducted at 925 deg. C for 15 min to observe the wettability of 7056 Glass on the underlying Kovar alloy discs. Finally, Kovar alloy and 7056 Glass were joined at thermal treatment temperature of 825-1000 deg. C with isothermal holding for 15 min at every interval of 25 deg. C. The wetting phenomenon and interface structure were observed under optical microscope and elemental analysis was also conducted on the glass-to-metal junction using an electron probe micro-analyzer. Experimental results reveal that Kovar alloy pre-oxidized at 700 deg. C and held isothermally for 5-15 min would have a denser and more compact oxide layer of 4-7 μm thick showing good adherence. Kovar alloy pre-oxidized at 700 deg. C and 10 min isothermal holding and heated in furnace filled with nitrogen only would obtain good wettability. Finally, thermal treatment temperature of 900 deg. C and 15 min isothermal holding resulted in a bigger surface area of the reaction layer and high-quality glass-to-metal junction

  9. Study of superficial films and of electrochemical behaviour of some nickel base alloys and titanium base alloys in solution representation of granitic, argillaceous and salted ground waters

    International Nuclear Information System (INIS)

    The corrosion behaviour of the stainless steels 304, 316 Ti, 25Cr-20Ni-Mo-Ti, nickel base alloys Hastelloy C4, Inconel 625, Incoloy 800, Ti and Ti-0.2% Pd alloy has been studied in the aerated or deaerated solutions at 200C and 900C whose compositions are representative of interstitial ground waters: granitic or clay waters or salt brine. The electrochemical techniques used are voltametry, polarization resistance and complexe impedance measurements. Electrochemical data show the respective influence of the parameters such as temperature, solution composition and dissolved oxygen, addition of soluble species chloride, fluoride, sulfide and carbonates, on which depend the corrosion current density, the passivation and the pitting potential. The inhibition efficiency of carbonate and bicarbonate activities against pitting corrosion is determined. In clay water at 900C, Ti and Ti-Pd show very high passivation aptitude and a broad passive potential range. Alloying Pd increases cathodic overpotential and also transpassive potential. It makes the alloy less sensitive to the temperature effect. Optical Glow Discharge Spectra show three parts in the composition depth profiles of surface films on alloys. XPS and SIMS spectrometry analyses are also carried out. Electron microscopy observation shows that passive films formed on Ti and Ti-Pd alloy have amorphous structure. Analysis of the alloy constituents dissolved in solutions, by radioactivation in neutrons, gives the order of magnitude of the Ni base alloy corrosion rates in various media. It also points out the preferential dissolution of alloying iron and in certain cases of chromium

  10. Microstructure of Hot-Deformed Cu-3Ti Alloy

    Directory of Open Access Journals (Sweden)

    Szkliniarz A.

    2016-03-01

    Full Text Available In the paper, results of investigations regarding temperature and strain rate effects on hot-deformed Cu-3Ti alloy microstructure are presented. Evaluation of the alloy microstructure was performed with the use of a Gleeble HDS-V40 thermal-mechanical simulator on samples subjected to uniaxial hot compression within 700 to 900ºC and at the strain rate of 0.1, 1.0 or 10.0 s-1 until 70% (1.2 strain. It was found that within the analyzed temperature and strain rate ranges, the alloy deformation led to partial or complete recrystallization of its structure and to multiple refinement of the initial grains. The recrystallization level and the average diameter of recrystallized grains increase with growing temperature and strain rate. It was shown that entirely recrystallized, fine-grained alloy structure could be obtained following deformation at the strain rate of min 10.0 s-1 and the temperature of 800°C or higher.

  11. Thermodiffusion Mo-B-Si coating on VN-3 niobium alloy

    International Nuclear Information System (INIS)

    Protective properties of complex Mo-B-Si-coating on niobium alloy VN-3 (4.7 mass.% Mo, 1.1 mass.% Zr, 0.1 mass.% C) have been studied. It is established, that the complex Mo-B-Si-coating ensures protection from oxidation of niobium alloys in the temperature range of 800-1200 degC for 1000-1500 hr, at 1600 degC - for 10 hr. High heat resistance of Mo-B-Si - coating at 800-1200 degC is determined by the presence of amorphous film of SiOΛ2 over the layer MoSiΛ2 and barrier boride layer on the boundary with the metal protected; decrease in the coating heat resistance at 1600 degC is related to the destruction of boride layer, decomposition of MoSiΛ2 for lower cilicides and loosening of SiOΛ2 film

  12. Titanium alloys. Advances in alloys, processes, products and applications

    OpenAIRE

    Blenkinsop, P.

    1993-01-01

    The last few years have been a period of consolidation of existing alloys and processes. While the aerospace industry remains the principal driving force for alloy development, the paper illustrates examples of new markets being established in "older" alloys, by a combination of product/process development and a re-examination of engineering design parameters. Considerable attention is still being directed towards the titanium aluminide systems, but other more conventional alloy developments ...

  13. ETDAC800变频器在纸机上的应用%The application of ETDAC800 frequency converter in paper machines

    Institute of Scientific and Technical Information of China (English)

    张超

    2014-01-01

    ETDAC800 frequency converter, adopted with tricore processor, becomes an advanced integrated AC driver due to its supreme control performance and lfexible field bus communication interface. The application of ETD AC800 frequency converter in paper machines was introduced in this paper, including the principle and implementation in speed cascade, load distribution, DC bus control and web-tension control.%ETDAC800变频器采用Infineon性能卓越的三核处理器(Tricore)设计,以其优异的控制性能和强大的组网功能成为业界领先的一体化交流电机驱动器。本文介绍了ETDAC800变频器在造纸机上的应用及取得的效果,重点阐述了速度级联、负载分配、母线电压控制和收卷张力控制的原理和实现。

  14. Oxidation of two ternary Fe-Cu-5Al alloys in 1×105 Pa pure oxygen at 700 ℃

    Institute of Scientific and Technical Information of China (English)

    XIANG Jun-huai; NIU Yan; WU Wei-tao; LIU Guo-dong

    2006-01-01

    The oxidation of two two-phase ternary Fe-Cu-Al alloys containing about 5% Al(mole fraction),one Fe-rich and one Cu-rich,were studied at 700 ℃ in 1×105 Pa pure oxygen. The Fe-rich alloy (Fe-15Cu-5Al) shows two quasi-parabolic stages,with a large increase of the parabolic rate constant after about 4 h. The presence of 5% Al does not change greatly the oxidation rate of Fe-15Cu-5Al with respect to a binary Fe-Cu alloy of similar composition,which was quite different from the situation of the same alloys oxidized at 800 ℃. Oxidation of Fe-15Cu-5Al at 700 ℃ produced an outer layer of iron oxides and an inner layer containing a mixture of copper metal,iron and aluminium oxide. On the contrary,the Cu-rich Fe-85Cu-5Al alloy presents a rather irregular kinetic behavior,with formation of an inner continuous alumina thin layer and a rather irregular outer layer. The outer layer with a rather irregular thickness was mainly composed of a matrix of copper oxides plus some aluminium and iron oxides presenting in the deep part of the layer at certain locations. As a result of the formation of a protective alumina layer,the presence of 5% Al greatly reduced the oxidation rate of Fe-85Cu-5Al with respect to a binary Fe-Cu alloy of similar composition,which was also quite different from the situation of the same alloys oxidized at 800 ℃. Moreover,the oxidation rate at 700 ℃ of the Fe-85Cu-5Al alloy was much lower than that of Fe-15Cu-5Al alloy due to the same reason..

  15. The 600 C and 800 C isothermal sections of the Zn-V-Sb system

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Siyuan; Zhu, Zhongxi; Xu, Qilin; Chen, Meiliang; Yin, Fucheng [Key Laboratory of Materials Design and Preparation Technology of Hunan Province, Xiangtan (China); Xiangtan Univ., Hunan (China). School of Mechanical Engineering; Ma, Wenbo [Xiangtan Univ., Hunan (China). College of Civil Engineering and Mechanics

    2016-01-15

    Phase relations in the Zn-V-Sb ternary system have been studied experimentally for the whole composition range for two temperatures, 600 C and 800 C, using scanning electron microscopy coupled with energy-dispersive spectrometry and X-ray diffraction. The ternary compound VZnSb, mentioned in the literature, still exists at 600 C, but disappears at 800 C. Moreover, the experimental results indicate that eight tri-phase regions could be confirmed in the system at 600 C, and four tri-phase regions exist in the 800 C isothermal section. The maximum solubility of Zn in V{sub 3}Sb{sub 2} and V{sub 3}Sb is up to 14.3 at.% and 3.6 at.% at 600 C, and 6.2 at.% and 2.7 at.% at 800 C, respectively.

  16. 800m Downscaled NEX CMIP5 Climate Projections for the Continental US

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — NOTICE: This dataset's 800m spatial resolution requires special consideration when executing Geo Data Portal Processing. Raw data subsets are not available for this...

  17. Coherence in the B800 Ring of Purple Bacteria LH2

    Science.gov (United States)

    Cheng, Y. C.; Silbey, R. J.

    2006-01-01

    We study the quantum coherence in the B800 ring and how it affects the dynamics of excitation energy transfer (EET) in photo-synthetic light-harvesting systems. From an analysis of the spectrum, we determine the disorder parameters for the B800 ring and show that the relatively weak electronic coupling between B800 pigments subtly changes the dynamics of EET and improves the uniformity and robustness of B800→B850 EET at room temperature, an example of how a multichromophoric assembly can exploit coherence to optimize the efficiency of photosynthesis. A molecular-level description for the dynamics of EET in the light-harvesting system may prove useful for understanding other nanoscale molecular assemblies and designing efficient nanoscale optical devices.

  18. 31 CFR 800.701 - Obligation of parties to provide information.

    Science.gov (United States)

    2010-07-01

    ..., ACQUISITIONS, AND TAKEOVERS BY FOREIGN PERSONS Provision and Handling of Information § 800.701 Obligation of... annual reports, written in a foreign language, shall be submitted in certified English translation....

  19. An Analysis on the Feature of the 800- meter Running and the Method of Improving Performance%对800m跑的能量代谢特点及对策探析

    Institute of Scientific and Technical Information of China (English)

    李军华

    2005-01-01

    800 m跑的能量供应入手,分析800 m跑的能量代谢基本特征.并对800 m运动员的速度能力、速度耐力能力及跑的基本技术进行了探讨,揭示800 m跑项目存在的一些问题,并提出了改进的手段及方法.

  20. INVESTIGATION OF MAGNESIUM ALLOYS MACHINABILITY

    Directory of Open Access Journals (Sweden)

    Berat Barıs BULDUM

    2013-01-01

    Full Text Available Magnesium is the lightest structural metal. Magnesium alloys have a hexagonal lattice structure, which affects the fundamental properties of these alloys. Plastic deformation of the hexagonal lattice is more complicated than in cubic latticed metals like aluminum, copper and steel. Magnesium alloy developments have traditionally been driven by industry requirements for lightweight materials to operate under increasingly demanding conditions. Magnesium alloys have always been attractive to designers due to their low density, only two thirds that of aluminium and its alloys [1]. The element and its alloys take a big part of modern industry needs. Especially nowadays magnesium alloys are used in automotive and mechanical (trains and wagons manufacture, because of its lightness and other features. Magnesium and magnesium alloys are the easiest of all metals to machine, allowing machining operations at extremely high speed. All standard machining operations such as turning, drilling, milling, are commonly performed on magnesium parts.

  1. Validity of the Polar V800 heart rate monitor to measure RR intervals at rest

    OpenAIRE

    Giles, David; Draper, Nick; Neil, William

    2015-01-01

    Purpose To assess the validity of RR intervals and short-term heart rate variability (HRV) data obtained from the Polar V800 heart rate monitor, in comparison to an electrocardiograph (ECG). Method Twenty participants completed an active orthostatic test using the V800 and ECG. An improved method for the identification and correction of RR intervals was employed prior to HRV analysis. Agreement of the data was assessed using intra-class correlation coefficients (ICC), Bland–Altman limits of a...

  2. Phase transitions ordering–phase separation in the Co3V alloy

    International Nuclear Information System (INIS)

    Highlights: • Ordering–phase separation transition in the Co3V alloy occurs two times. • A tendency to phase separation takes place above 800 and below 450 °C. • Ordering with L12 phase formation occurs in the 450–800 °C interval. - Abstract: An electron microscopic study of the Co3V alloy microstructure formed after heat treatment at different temperatures has been conducted. Two phase transitions ordering–phase separation have been discovered, which occur in the alloy at temperatures of about 450 and 800 °C. At high-temperature phase separation, the microstructure consists of bcc vanadium atom particles and a fcc solid solution; at low-temperature phase separation, it is a cellular structure, in which the cellular boundaries are enriched in vanadium. In the region of ordering, it consists of particles of the Co3V chemical compound, randomly distributed in the solid solution. It is shown that at none of the temperatures do these microstructures correspond to those shown in the Co–V phase diagram.

  3. Oxidation of high-temperature alloys J(superalloys) at elevated temperatures in air.II

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, N.; Shahid, K.A.; Rahman, S. [Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan)] [and others

    1995-04-01

    In continuation of previous work, the oxidation behavior of three more alloys, namely UHBA 25L, Sanicro 28, and Inconel 690, was studied at high temperatures (600 to 1200{degrees}C). The oxidation kinetics of UHBA 25L and Sanicro 28 followed the parabolic-rate law at 800 and 1000{degrees}C. At 600{degrees}C oxidation rates were very low, while at 1200{degrees}C the parabolic-rate law was initially observed, followed by {open_quotes}breakaway.{close_quotes} Both alloys suffered extensive spalling at all temperatures, despite their high Cr contents of about 25% and 27%, respectively. This is attributed to significant amounts of Mn present. Sanicro 28, with higher Cr, suffered an early breakaway at 100{degrees}C because of the presence of Mo, which forms a low-melting oxide. Inconel 690 showed mixed behavior at 600 and 800{degrees}C, parabolic at 1000{degrees}C and cubic at 1200{degrees}C. Inconel 690 and Incoloy 800H have the best overall performance for the range of temperature and exposure time under study. This may be ascribed to the absence of Mo, the presence of small amounts of Ti and Al, and relatively small amount of Mn in these alloys.

  4. Structural thermodynamics of alloys

    CERN Document Server

    Manenc, Jack

    1973-01-01

    Technical progress has for a very long time been directly dependent on progress in metallurgy, which is itself connected with improvements in the technology of alloys. Metals are most frequently used in the form of alloys for several reasons: the quantity of pure metal in its native state in the earth's crust is very limited; pure metals must be extracted from ores which are themselves impure. Finally, the methods of treatment used lead more easily to alloys than to pure metals. The most typical case is that of iron, where a pure ore may be found, but which is the starting point for cast iron or steel, alloys of iron and carbon. In addition, the properties of alloys are in general superior to those of pure metals and modem metallurgy consists of controlling these properties so as to make them conform to the requirements of the design office. Whilst the engineer was formerly compelled to adapt his designs and constructions to the materials available, such as wood, stone, bronze, iron, cast iron and ordinary st...

  5. INVESTIGATION OF MAGNESIUM ALLOYS MACHINABILITY

    OpenAIRE

    Berat Barıs BULDUM; Aydın SIK; Iskender OZKUL

    2013-01-01

    Magnesium is the lightest structural metal. Magnesium alloys have a hexagonal lattice structure, which affects the fundamental properties of these alloys. Plastic deformation of the hexagonal lattice is more complicated than in cubic latticed metals like aluminum, copper and steel. Magnesium alloy developments have traditionally been driven by industry requirements for lightweight materials to operate under increasingly demanding conditions. Magnesium alloys have always been attra...

  6. Productive Machining of Titanium Alloys

    OpenAIRE

    Čejka, Libor

    2013-01-01

    This diploma thesis is focused on a productive machining of titanium alloys. At the beginning it deals about titanium and its alloys. It describes chip generation mechanism, tool blunting and surface quality. Further it contains modern strategies of efficient titanium alloys machining. Then it analyzes contemporary manufacturing technology of hinge made of titanium alloy Ti-6Al-4V in Frentech Aerospace s.r.o. company, and at the end finds possibility of savings by inovation of roughing process.

  7. Study of the oxidation of Fe-Cr alloys at high temperatures; Estudo da oxidacao de ligas Fe-Cr a altas temperaturas

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, J.F.; Sabioni, A.C.S. [Universidade Federal de Ouro Preto (LDM/DF/UFOP), MG (Brazil). Dept. de Fisica. Lab. de Difusao em Materiais; Trindade, V.B. [Universidade Federal de Ouro Preto (DEMM/UFOP), MG (Brazil). Dept. de Engenharia Metalurgica e de Materiais; Ji, V. [Laboratoire d' Etude des Materiaux Hors-Equilibre (LEMHE), Orsay (France)

    2010-07-01

    The high temperature oxidation behavior of Fe-1.5%Cr, Fe-5.0%Cr, Fe-10%Cr and Fe- 15%Cr model alloys were investigated from 700 to 850 deg C, in air atmosphere. The oxidation treatments were performed in a thermobalance with a sensitivity of 1{mu}g. The oxide films grown by oxidation of the alloys were characterized by scanning electronic microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The oxide films are Fe-Cr spinels with variable composition depending on the alloy composition. For all conditions studied, the oxidation kinetics of these alloys follow a parabolic law. The comparison of the oxidation rates of the four alloys, at 700 deg C, shows that the parabolic oxidation constants decrease from 1.96x10{sup -9}g{sup 2}.cm{sup -4}.s{sup -1}, for the alloy Fe-1.5% Cr, to 1.18 x 10-14g{sup 2}.cm{sup -4}.s{sup -1} for the alloy Fe-15% Cr. Comparative analysis of the oxidation behavior of the Fe-10%Cr and Fe-15%Cr alloys, between 700 and 850 deg C, shows that the oxidation rates of these alloys are comparable to 800 deg C, above this temperature the Fe-10%Cr alloy shows lower resistance to oxidation. (author)

  8. De-alloyed platinum nanoparticles

    Science.gov (United States)

    Strasser, Peter; Koh, Shirlaine; Mani, Prasanna; Ratndeep, Srivastava

    2011-08-09

    A method of producing de-alloyed nanoparticles. In an embodiment, the method comprises admixing metal precursors, freeze-drying, annealing, and de-alloying the nanoparticles in situ. Further, in an embodiment de-alloyed nanoparticle formed by the method, wherein the nanoparticle further comprises a core-shell arrangement. The nanoparticle is suitable for electrocatalytic processes and devices.

  9. Structural formation of aluminide phases on titanium alloy during annealing

    International Nuclear Information System (INIS)

    Full text: The aluminum layer on the surface of titanium alloy has been formed by thermal deposition. The structural formation of aluminide phases on the surface has been studied. The sequence of structural transformations at the Ti/Al interface is limited by the reaction temperature and time. The sequence of aluminide phase formation is occurred in compliance with Ti-Al equilibrium phase diagram. At the initial stages at the Ti/Al interface the Al3Ti alloy starts forming as a result of interdiffusion, and gradually the whole aluminum films is spent on the formation of this layer. The Al3Ti layer decomposes with the increase of temperature (>600C). At 800C the two-phase (Ti3Al+TiAl) layer is formed on the titanium surface. The TiAl compound is unstable and later on with the increase of the exposure time at 800C gradually transforms into the Ti3Al. The chain of these successive transformations leads to the formation of the continuous homogeneous layer consisting of the Ti3Al compound on the surface. At temperatures exceeding the allotropic transformation temperature (>900C) the Ti3Al compound starts decomposing. All structural changes taking place at the Ti/Al interface are accompanied by considerable changes in micro hardness. The structure of initial substrate influences on kinetics of phase transformation and microstructure development. (author)

  10. Shape Memory Alloys

    Directory of Open Access Journals (Sweden)

    Deexith Reddy

    2016-07-01

    Full Text Available Shape memory alloys (SMAs are metals that "remember" their original shapes. SMAs are useful for such things as actuators which are materials that "change shape, stiffness, position, natural frequency, and other mechanical characteristics in response to temperature or electromagnetic fields" The potential uses for SMAs especially as actuators have broadened the spectrum of many scientific fields. The study of the history and development of SMAs can provide an insight into a material involved in cutting-edge technology. The diverse applications for these metals have made them increasingly important and visible to the world. This paper presents the working of shape memory alloys , the phenomenon of super-elasticity and applications of these alloys.

  11. 49 CFR 177.800 - Purpose and scope of this part and responsibility for compliance and training.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Purpose and scope of this part and responsibility for compliance and training. 177.800 Section 177.800 Transportation Other Regulations Relating to... MATERIALS REGULATIONS CARRIAGE BY PUBLIC HIGHWAY General Information and Regulations § 177.800 Purpose...

  12. 20 CFR 670.800 - How do Job Corps centers and service providers become involved in their local communities?

    Science.gov (United States)

    2010-04-01

    ... INVESTMENT ACT Community Connections § 670.800 How do Job Corps centers and service providers become involved... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false How do Job Corps centers and service providers become involved in their local communities? 670.800 Section 670.800 Employees' Benefits...

  13. Double Glow Plasma Surface Alloyed Burn-resistant Titanium Alloy

    Institute of Scientific and Technical Information of China (English)

    ZHANGPing-ze; XUZhong; HEZhi-yong; ZHANGGao-hui

    2004-01-01

    Conventional titanium alloy may be ignited and burnt under high temperature, high pressure and high gas flow velocity condition. In order to avoid this problem, we have developed a new kind of burn-resistant titanium alloy-double glow plasma surface alloying burn-resistant titanium alloy. Alloying element Cr, Mo, Cu are induced into the Ti-6A1-4V and Ti-6.5Al-0.3Mo-1.5Zr-0.25Si substrates according to double glow discharge phenomenon, Ti-Cr ,Ti-Mo, Ti-Cu binary burn-resistant alloy layers are formed on the surface of Ti-6A1-4V and Ti-6.5Al-0.3Mo-1.5Zr-0.25Si alloys. The depth of the surface burn-resistant alloy layer can reach to above 200 microns and alloying element concentration can reach 90%. Burn-resistant property experiments reveal that if Cr concentration reach to 14%, Cu concentration reach to 12%, Mo concentration reach to 10% in the alloying layers, ignition and burn of titanium alloy can be effectively avoided.

  14. Double Glow Plasma Surface Alloyed Burn-resistant Titanium Alloy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ping-ze; XU Zhong; HE Zhi-yong; ZHANG Gao-hui

    2004-01-01

    Conventional titanium alloy may be ignited and burnt under high temperature, high pressure and high gas flow velocity condition. In order to avoid this problem, we have developed a new kind of burn-resistant titanium alloy-double glow plasma surface alloying burn-resistant titanium alloy. Alloying element Cr, Mo, Cu are induced into the Ti-6Al-4V and Ti-6.5Al-0.3Mo-l.5Zr-0.25Si substrates according to double glow discharge phenomenon, Ti-Cr ,Ti-Mo, Ti-Cu binary burn-resistant alloy layers are formed on the surface of Ti-6Al-4V and Ti-6.5Al-0.3Mo-l.5Zr-0.25Si alloys. The depth of the surface burn-resistant alloy layer can reach to above 200 microns and alloying element concentration can reach 90%.Burn-resistant property experiments reveal that if Cr concentration reach to 14%, Cu concentration reach to 12%, Mo concentration reach to 10% in the alloying layers, ignition and burn of titanium alloy can be effectively avoided.

  15. Phase equilibria, microstructure, and high temperature oxidation resistance of novel refractory high-entropy alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gorr, B., E-mail: gorr@ifwt.mb.uni-siegen.de [Institut für Werkstofftechnik, Universität Siegen, Paul-Bonatz-Str. 9-11, 57068 Siegen (Germany); Azim, M.; Christ, H.-J. [Institut für Werkstofftechnik, Universität Siegen, Paul-Bonatz-Str. 9-11, 57068 Siegen (Germany); Mueller, T. [Institut für Bau- und Werkstoffchemie, Universität Siegen, Paul-Bonatz-Str. 9-11, 57068 Siegen (Germany); Schliephake, D.; Heilmaier, M. [Institut für Angewandte Materialien – Werkstoffkunde (IAM-WK), Karlsruhe Institute of Technology (KIT), Engelbert-Arnold-Str. 4, D-76131 Karlsruhe (Germany)

    2015-03-05

    Highlights: • A new candidate for applications at high temperature is proposed. • The calculated melting point of the alloy is 1700 °C. • The alloy possesses a simple microstructure. • The alloy exhibits perspectives in terms of mechanical properties and oxidation resistance. - Abstract: A new refractory high-entropy alloy system Mo–W–Al–Cr–x is proposed as a family of candidate materials for structural applications at high temperatures. Thermodynamic assessment was used to set the chemical composition of the first alloy as 20Mo–20W–20Al–20Cr–20Ti (at.%) with a calculated melting temperature of about 1700 °C. A single disordered BCC phase should be stable at high temperatures between 1077 °C and 1700 °C. Microstructural examination and XRD results clearly show that the alloy in the as-cast condition exhibits a non-homogeneous microstructure with pronounced dendritic and interdendritic regions. Heat treatment processes, however, reveal a strong tendency of the alloy 20Mo–20W–20Al–20Cr–20Ti to homogenize. While possessing a high hardness of around 800HV, the crack-free indents allow the assumption that the alloy studied may be intrinsically ductile at room temperature. Despite the fact that the alloy possesses 40 at.% of refractory elements, high temperature oxidation tests show a surprisingly good oxidation resistance. Strategies to enhance the long-term stability of the disordered BCC phase aiming at achieving the required mechanical properties as well as optimizing the alloy’s chemical composition in terms of high temperature oxidation resistance are discussed.

  16. Machining of Titanium Alloys

    OpenAIRE

    Karásek, Jan

    2008-01-01

    The main goal of this work is the analysis of manufacturing costs for the component of wheel´s blower. Followed by setting up the size of specific cutting force for milling operation of the titanium alloy Ti-Al6-Mo2-Cr2-Fe-Si, the used tool was a milling cutter which is made out of sintered carbide with conical and spherical face. The final values which are at intervals of 1500 to 1800 MPa were compared with the values of the Sandvik Coromant firm kc = 1690 MPa, for titanium alloy with the st...

  17. Tungsten Alloy Outgassing Measurements

    CERN Document Server

    Rutherfoord, John P; Shaver, L

    1999-01-01

    Tungsten alloys have not seen extensive use in liquid argon calorimeters so far. Because the manufacturing process for tungsten is different from the more common metals used in liquid argon there is concern that tungsten could poison the argon thereby creating difficulties for precision calorimetry. In this paper we report measurements of outgassing from the tungsten alloy slugs proposed for use in the ATLAS FCal module and estimate limits on potential poisoning with reasonable assumptions. This estimate gives an upper limit poisoning rate of

  18. Galvanic corrosion in odontological alloys

    International Nuclear Information System (INIS)

    Galvanic corrosion can occur when different alloys are placed in direct contact within the oral cavity or within tissues. Concern has been expressed associated with the coupling of selected restorative materials as well as implant material with various alloys used for restorative procedures. This could be critical if the crown or bridge had subgingival finish line with a metallic zone in contact with the tissue, and the implant was made in titanium alloy. The present work shows the results of galvanic coupling studies done on implants of titanium alloy connected to nickel-chromium and cobalt-chromium alloys. (Author)

  19. Experimental investigation of hardness of FSW and TIG joints of Aluminium alloys of AA7075 and AA6061

    Directory of Open Access Journals (Sweden)

    Chetan Patil

    2016-07-01

    Full Text Available This paper reports hardness testing conducted on welded butt joints by FSW and TIG welding process on similar and dissimilar aluminium alloys. FSW joints were produced for similar alloys of AA7075T651 and dissimilar alloys of AA7075T651- AA6061T6. The Friction stir welds of AA7075 & AA6061 aluminium alloy were produced at different tool rotational speeds of 650,700, 800, 900, 1000 and transverse speed of 30, 35, 40 mm/min. TIG welding was conducted along the rolling direction of similar and dissimilar aluminium plates. The Brinell hardness testing techniques were employed to conduct the tests; these tests were conducted on the welds to ascertain the joint integrity before characterization to have an idea of the quality of the welds

  20. Synthesis of high-quality near-infrared-emitting CdTeS alloyed quantum dots via the hydrothermal method

    International Nuclear Information System (INIS)

    We present a facile one-pot method to fabricate water-dispersed near-infrared-emitting (650-800 nm) CdTeS alloyed quantum dots with high photoluminescence quantum yields (PL QYs). Due to the hydrolysis of thiol ligands, the sulfur was incorporated into the CdTe nanocrystals, forming CdTeS alloyed QDs. The effects of the type of thiol ligands, ligand-to-Cd molar ratio, and precursor concentration on the QDs were investigated, and thus high-quality water-dispersed CdTeS alloyed QDs (PL QYs 68%) were prepared with a high efficiency via the hydrothermal method. Water-dispersed CdTeS alloyed QDs with excellent emissions in the near-IR spectrum window have great potential in biological and medical applications especially in in vivo imaging

  1. Effect of austenitization heat treatment on the magnetic properties of Fe-40wt% Ni-2wt% Mn alloy

    Institute of Scientific and Technical Information of China (English)

    S. Buyukakkas; H. Aktas; S. Akturk

    2007-01-01

    The effect of austenitization heat treatment on magnetic properties was examined by means of M(o)ssbauer spectroscopy on an Fe-40wt%Ni-2wt%Mn alloy. The morphology of the alloy was obtained by using scanning electron microscopy (SEM) under different heat treatment conditions. The magnetic behavior of the non heat-treated alloy is ferromagnetic. A mixed magnetic structure including both paramagnetic and ferromagnetic states was obtained at 800℃ after 6 and 12 h heat treatments. In addition, the magnetic structure of the heat-treated alloy at 1150℃ for 12 h was ferromagnetic. With the volume fraction changing, the effective hyperfine field of the ferromagnetic austenite phase and isomery shift values were also determined by M(o)ssbauer spectroscopy.

  2. Development of low coefficient of thermal expansion (CTE) nickel alloys for potential use as interconnects in SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Alman, David E.; Jablonski, Paul D.

    2004-11-01

    This paper deals with the development of low coefficient of thermal expansion (CTE) nickel-base superalloys for potential use as interconnects for SOFC. Ni-Mo-Cr alloys were formulated with CTE on the order of 12.5 to 13.5 x10-6/°C. The alloys were vacuum induction melted and reduced to sheet via a combination of hot and cold working. Dilatometry was used to measure CTE of the alloys. Oxidation behavior of the alloys at 800°C in dry and moist air is reported. The results are compared to results for Haynes 230 (a commercial Ni-base superalloy) and for Crofer 22APU (a commercial ferritic stainless steel designed specifically for use as an SOFC interconnect).

  3. Carburization of austenitic alloys by gaseous impurities in helium

    International Nuclear Information System (INIS)

    The carburization behavior of Alloy 800H, Inconel Alloy 617 and Hastelloy Alloy X in helium containing various amounts of H2, CO, CH4, H2O and CO2 was studied. Corrosion tests were conducted in a temperature range from 649 to 10000C (1200 to 18320F) for exposure time up to 10,000 h. Four different helium environments, identified as A, B, C, and D, were investigated. Concentrations of gaseous impurities were 1500 μatm H2, 450 μatm CO, 50 μatm CH4 and 50 μatm H2O for Environment A; 200 μatm H2, 100 μatm CO, 20 μatm CH4, 50 μatm H2O and 5 μatm CO2 for Environment B; 500 μatm H2, 50 μatm CO, 50 μatm CH4 and 2O for Environment C; and 500 μatm H2, 50 μatm CO, 50 μatm CH4 and 1.5 μatm H2O for Environment D. Environments A and B were characteristic of high-oxygen potential, while C and D were characteristic of low-oxygen potential. The results showed that the carburization kinetics in low-oxygen potential environments (C and D) were significantly higher, approximately an order of magnitude higher at high temperatures, than those in high-oxygen potential environments (A and B) for all three alloys. Thermodynamic analyses indicated no significant differences in the thermodynamic carburization potential between low- and high-oxygen potential environments. It is thus believed that the enhanced carburization kinetics observed in the low-oxygen potential environments were related to kinetic effects. A qualitatively mechanistic model was proposed to explain the enhanced kinetics. The present results further suggest that controlling the oxygen potential of the service environment can be an effective means of reducing carburization of alloys

  4. Cr{sub 2}Nb-based alloy development

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.T.; Tortorelli, P.F.; Horton, J.A. [Oak Ridge National Lab., TN (United States)] [and others

    1995-06-01

    The objective of this task is to develop a new generation of structural materials based on intermetallic alloys for use as critical hot components in advanced fossil energy conversion systems. The intermetallic phase, Cr{sub 2}Nb, with a complex cubic structure (C-15) has been selected for this development because of its high melting point (1770{degrees}C), relatively low material density (7.7 g/cm{sup 2}), excellent high-temperature strength (at 1000 to 1250{degrees}C), and potential resistance to oxidation and corrosion. This intermetallic phase, like many other Laves phases, has a wide range of compositional homogeneity suggesting the possibility of improving its mechanical and metallurgical properties by alloying additions. The major engineering concern with Cr{sub 2}Nb and other A{sub 2}B Laves phases is their poor fracture toughness and fracture resistance at ambient temperatures. The single-phase Cr{sub 2}Nb is very hard ({approximately}800 DPH) and brittle at room temperature. Because of this brittleness, the development effort has concentrated on two-phase structures containing the hard intermetallic phase Cr{sub 2}Nb and the softer Cr-rich solid solution phase. Potential applications of Cr-Cr{sub 2}Nb alloys include hot components (for example, air heat exchangers and turbine blades) in advanced energy conversion systems and heat engines, wear-resistant parts in coal handling systems (e.g., nozzles), drill bits for oil/gas wells, and valve guides in diesel engines. Current studies are focuses on enhancement of fracture resistance in tension at ambient temperatures and oxidation resistance above 1000{degrees}C. This report summarizes recent progress on controlling microstructure and improving the mechanical and metallurgical properties and the high-temperature corrosion behavior of Cr-Cr{sub 2}Nb alloys through alloying conditions, material processing, and heat treatment.

  5. Erosion-Corrosion of Iron and Nickel Alloys at Elevated Temperature in a Combustion Gas Environment

    Energy Technology Data Exchange (ETDEWEB)

    Tylczak, Joseph [NETL

    2014-05-02

    This paper reports on the results of a study that compares the erosion-corrosion behavior of a variety of alloys (Fe- 2¼Cr 1Mo, 304 SS, 310 SS, Incoloy 800, Haynes 230 and a Fe3Al) in a combustion environment. Advanced coal combustion environments, with higher temperatures, are driving re-examination of traditional and examination of new alloys in these hostile environments. In order to simulate conditions in advanced coal combustion boilers, a special erosion apparatus was used to allow for impingement of particles under a low abrasive flux in a gaseous environment comprised of 20 % CO2, 0.05 % HCl, 77 % N2, 3 % O2, and 0.1 % SO2. Tests were conducted at room temperature and 700 °C with ~ 270 μm silica, using an impact velocity of 20 m/s in both air and the simulated combustion gas environment. The erosion-corrosion behavior was characterized by gravimetric measurements and by examination of the degraded surfaces optically and by scanning electron microscopy (SEM). At room temperature most of the alloys had similar loss rates. Not surprisingly, at 700 °C the lower chrome-iron alloy had a very high loss rate. The nickel alloys tended to have higher loss rates than the high chrome austenitic alloys.

  6. Evaluation of the CoCrTaPt alloy for longitudinal magnetic recording

    Science.gov (United States)

    Cheng, Yuanda; Sedighi, Mojtaba; Lam, Irene; Gardner, Richard A.; Yang, ZhiJun; Scheinfein, Michael R.

    1994-05-01

    A quaternary alloy of CoCrTaPt with a composition of 80-10-4-6 (in at. %) was evaluated for its magnetic and recording properties. Samples of C/CoCrTaPt/Cr recording media were prepared by dc magnetron sputtering on circumferentially textured Al/NiP substrates. The effects on static magnetic properties and recording performance were studied for different substrate preheating times, Cr underlayer thicknesses, and Co-alloy layer thicknesses. It was found that both the coercivity Hc and remanent magnetization Mr increased with substrate preheating time. Hc also increased with Cr underlayer thickness, as expected. The Mrδ value depended linearly on the Co-alloy layer thickness. In addition, we found that the coercivity increased dramatically as the magnetic layer thickness decreased from ˜800 to ˜200 Å. For a sample with a 235-Å CoCrTaPt magnetic layer and ˜1000-Å Cr underlayer, the coercivity was found to be ≳2700 Oe. Parametric evaluation showed that CoCrTaPt samples have performance similar to samples of CoCrTa and, because of the Pt addition, the CoCrTaPt alloy offers significantly higher attainable coercivities than the CoCrTa alloy. Therefore, the CoCrTaPt alloy proves to be a good candidate for use in high density recording media which require coercivity of higher than 2000 Oe.

  7. The development of a tensile-shear punch correlation for yield properties of model austenitic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hankin, G.L.; Faulkner, R.G. [Loughborough Univ. (United Kingdom); Hamilton, M.L.; Garner, F.A. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-08-01

    The effective shear yield and maximum strengths of a set of neutron-irradiated, isotopically tailored austentic alloys were evaluated using the shear punch test. The dependence on composition and neutron dose showed the same trends as were observed in the corresponding miniature tensile specimen study conducted earlier. A single tensile-shear punch correlation was developed for the three alloys in which the maximum shear stress or Tresca criterion was successfully applied to predict the slope. The correlation will predict the tensile yield strength of the three different austenitic alloys tested to within {+-}53 MPa. The accuracy of the correlation improves with increasing material strength, to within {+-} MPa for predicting tensile yield strengths in the range of 400-800 MPa.

  8. Influence of heat treatment on properties of ti-nb alloys

    Directory of Open Access Journals (Sweden)

    L. Kunčicka

    2014-04-01

    Full Text Available Ti-Nb alloys are of a large potential for industrial, as well as biomedical utilisation. Oxygen content in the alloy is a parameter influencing its properties and cannot be neglected. The main focus of this paper is on observation of influence of annealing time on oxygen content in the structure of Ti – 20,7 (at.% Nb alloy. Four groups of the samples were annealed at the temperature of 800 °C from 15 to 60 minutes with 15 min. step. As it was proven by the analysis, the oxygen content increased with increasing annealing time. Moreover, microhardness measurements showed increasing trend of HV microhardness value with increasing oxygen content.

  9. Surface morphology of highly ordered nanotube formed and laser textured beta titanium alloys.

    Science.gov (United States)

    Kim, Jae-Un; Jeong, Yong-Hoon; Choe, Han-Cheol

    2013-03-01

    The aim of the present study is to produce and characterize a well-controlled surface texture on Ti-35Nb-xHf alloys to promote osseointegration. Ti-35Nb-xHf (x = 0, 3, 7 and 15 wt.%) alloys were prepared by arc melting and heat treated for 12 hr at 1000 degrees C in an argon atmosphere and then water quenching. For surface texturing, an amplified Ti: sapphire laser system was used for generating 184 femtosecond (FS, 10(-15) sec) laser pulses with the pulse energy over 30 mJ at a 1 kHz repetition rate with a central wavelength of 800 nm. The nanotube formation was achieved by anodizing a Ti-35Nb-xHf alloy in H3PO4 electrolytes containing 0.8 wt.% NaF at room temperature. The surface morphology of nano/micro structure will enhance osseointegration and cell adhesion.

  10. The development of a tensile-shear punch correlation for yield properties of model austenitic alloys

    International Nuclear Information System (INIS)

    The effective shear yield and maximum strengths of a set of neutron-irradiated, isotopically tailored austentic alloys were evaluated using the shear punch test. The dependence on composition and neutron dose showed the same trends as were observed in the corresponding miniature tensile specimen study conducted earlier. A single tensile-shear punch correlation was developed for the three alloys in which the maximum shear stress or Tresca criterion was successfully applied to predict the slope. The correlation will predict the tensile yield strength of the three different austenitic alloys tested to within ±53 MPa. The accuracy of the correlation improves with increasing material strength, to within ± MPa for predicting tensile yield strengths in the range of 400-800 MPa

  11. In Situ Nanocrystallization-Induced Hardening of Amorphous Alloy Matrix Composites Consolidated by Spark Plasma Sintering

    Science.gov (United States)

    Singh, Ashish; Paul, Tanaji; Katakam, Shravana; Dahotre, Narendra B.; Harimkar, Sandip P.

    2016-07-01

    In situ nanocrystallization of amorphous alloys has recently emerged as a suitable technique for forming nanocomposites with improved mechanical properties. In this paper, we report on the spark plasma sintering (SPS) of Fe-based amorphous alloys with in situ-formed nanocrystals of (Fe,Cr)23(C,B)6. The SPS was performed with a range of sintering temperatures (570-800°C) in and above the supercooled liquid region of the alloy. Significant enhancement in relative density was observed with increasing sintering temperature due to particle deformation and improved interparticle contacts. The formation of nanocrystalline particles and enhanced densification resulted in an increase in the hardness of the nanocomposites from about 1150-1375 VHN.

  12. Effect of yttrium on the twinning and plastic deformation of AE magnesium alloy under ballistic impact

    Energy Technology Data Exchange (ETDEWEB)

    Asgari, H., E-mail: hamed.asgari@usask.ca [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon (Canada); Odeshi, A.G.; Szpunar, J.A. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon (Canada); Zeng, L.J.; Olsson, E. [Department of Applied Physics, Chalmers University of Technology, Göteborg (Sweden); Li, D.Y. [Department of Chemical and Materials Engineering, University of Alberta, Edmonton (Canada)

    2015-01-19

    In this research, effect of yttrium on the texture formation, microstructural evolution and mechanical response of AE42 and AE44 cast magnesium alloys were investigated under ballistic impact. The selected strain rates were 800 and 1100 s{sup −1} and the tests were conducted using Split Hopkinson Pressure Bar. It was inferred that after high velocity impact, a weaker basal texture developed in the samples with lower content of yttrium. Experimental results also showed that by increasing the concentration of yttrium in the cast AE alloys, strength, ductility and dislocation density of the impacted alloys increased but, the fraction of twinning decreased, which indicate the effective influence of yttrium on the nucleation and growth of twins. Moreover, it was inferred that accumulation of dislocations at intersections of the twins led to the cracking and fracture of the samples under shock loading conditions.

  13. Structure and properties of sintered titanium alloyed with aluminium, molybdenum and oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Anokhin, V.M.; Petrunko, A.N. [State Research and Design Titanium Institute, Zaporozhye (Ukraine); Ivasishin, O.M. [Institute for Metal Physics, National Academy of Sciences of Ukraine, 36 Vernadsky St, 142 Kiev (Ukraine)

    1998-03-15

    Titanium alloys of Ti-Al-Mo-O system were manufactured by blended elemental powder method using Ti, Al, Mo and TiO{sub 2} powders as starting materials. It was found that cold compaction pressure of 800 MPa followed by sintering at 1150-1200 C, for 4 h provided sufficient densification of titanium materials. Complete dissolution of alloying elements in the titanium matrix resulted in a good combination of mechanical properties. Examples of alloys chosen for possible application were Ti-(1.5-2.0)%Mo-0.7%TiO{sub 2} and Ti-2%Al-2%Mo. The latter has already been tried for manufacturing parts in automotive industry. (orig.) 3 refs.

  14. Development of ODS FeCrAl alloys for accident-tolerant fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Dryepondt, Sebastien N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hoelzer, David T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Unocic, Kinga A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-18

    FeCrAl alloys are prime candidates for accident-tolerant fuel cladding due to their excellent oxidation resistance up to 1400 C and good mechanical properties at intermediate temperature. Former commercial oxide dispersion strengthened (ODS) FeCrAl alloys such as PM2000 exhibit significantly better tensile strength than wrought FeCrAl alloys, which would alloy for the fabrication of a very thin (~250 m) ODS FeCrAl cladding and limit the neutronic penalty from the replacement of Zr-based alloys by Fe-based alloys. Several Fe-12-Cr-5Al ODS alloys where therefore fabricated by ball milling FeCrAl powders with Y2O3 and additional oxides such as TiO2 or ZrO2. The new Fe-12Cr-5Al ODS alloys showed excellent tensile strength up to 800 C but limited ductility. Good oxidation resistance in steam at 1200 and 1400 C was observed except for one ODS FeCrAl alloy containing Ti. Rolling trials were conducted at 300, 600 C and 800 C to simulate the fabrication of thin tube cladding and a plate thickness of ~0.6mm was reached before the formation of multiple edge cracks. Hardness measurements at different stages of the rolling process, before and after annealing for 1h at 1000 C, showed that a thinner plate thickness could likely be achieved by using a multi-step approach combining warm rolling and high temperature annealing. Finally, new Fe-10-12Cr-5.5-6Al-Z gas atomized powders have been purchased to fabricate the second generation of low-Cr ODS FeCrAl alloys. The main goals are to assess the effect of O, C, N and Zr contents on the ODS FeCrAl microstructure and mechanical properties, and to optimize the fabrication process to improve the ductility of the 2nd gen ODS FeCrAl while maintaining good mechanical strength and oxidation resistance.

  15. Impact of irradiation on the tensile and fatigue properties of two titanium alloys

    International Nuclear Information System (INIS)

    The attachment of the first wall modules of the ITER FEAT fusion reactor is designed using flexible connectors made from titanium alloys.. An assessment of the tensile and fatigue performance of two candidate alloys, a classical two phase Ti6Al4V alloy and a monophase α alloy Ti5Al2.5Sn, has been carried out using 590 MeV protons for the simulation of the fusion neutrons. The dose deposited was up to 0.3 dpa and the irradiation temperature was between 40 deg. C and 350 deg. C. The unirradiated tensile performances of both alloys are roughly identical. The radiation hardening is much stronger in the α+β alloy compared with the α alloy, and the ductility is correspondingly strongly reduced. A very fine precipitation observed by TEM in the primary and secondary α grains of the dual phase alloy seems to be the cause of the intense radiation hardening observed. Two different regimes have been observed in the behaviour of the cyclic stresses. At a high imposed strain, the softening is small in the Ti6Al4V and larger in the Ti5Al2.5Sn. At a low imposed strain, and for both alloys, cyclic softening occurs up to about 800 cycles, but then a transition occurs, after which a regime of cyclic hardening appears. This cyclic hardening disappears after irradiation. In both materials, and for all test conditions, the compressive stress of the hysteresis loop was found to be larger than the tensile stress. The stress asymmetry seems to be triggered by the plastic deformation. The fatigue resistance of the Ti5Al2.5Sn alloy is slightly better than that of the Ti6Al4V alloy. The irradiation did not significantly affect the fatigue performance of both alloys, except for high imposed strains, where a life reduction was observed in the case of the Ti6Al4V alloy. SEM micrographs showed that the fractures were transgranular and pseudo-brittle

  16. Deformation behaviour of laser-welded tube blank of TA15 Ti-alloy for gas forming at elevated temperature

    OpenAIRE

    Wang Kehuan; Liu Gang; Yuan Shijian

    2015-01-01

    Deformation behaviour of laser-welded tube blank of TA15 Ti-alloy at elevated temperature was investigated by both hot tensile tests and high pressure gas forming(HPGF). The hot tensile tests were carried out with four different specimens at 800 ∘C with an initial strain rate of 1.00×10−2 s−1 and HPGF test was performed at 800 ∘C with a constant pressure of 9.5MPa. The tensile results show that base material with equiaxed microstructure exhibited good formability and grain boundary sliding (G...

  17. Kinetic study of wet oxidation of Si0.5Ge0.5 alloy by Rutherford backscattering spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The oxidation of Si0. sGeo.5 alloy has been investigated at the temperatures of 800℃ and 900 ℃. Rutherford backscattering spectroscopy has been employed to determine the composition and thickness of the oxide layers. Only Sio.5Geo. 5O2 layer formed during the oxidation at 800℃, whilst three layers, Si0.5Ge0.5O2, SiO2 and Ge, are existed after the oxidation at 900℃. Experimental results are interpreted by adding a germanium flux F4 in Deal-Grove oxidation model of Silicon.

  18. BN-800 reactor is a new stage in transition to innovative nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Poplavsky, V.M.; Chebeskov, A.N.; Matveev, V.I. [State Scientific Center of the Russian Federation, Institute for Physics and Power Engineering named after A.I. Leypunsky, Obninsk Kaluga region (Russian Federation)

    2007-07-01

    This paper presents the perspectives of nuclear power development in Russia and the reasons why it is necessary to use for that fast reactor technology. Some features of fast reactor technology and main ideas and technical approaches that have been used in the design of the BN-800 sodium cooled fast reactor are given as well. The BN-800 design is based on the BN-600 design with a series of innovative modifications: -) changing the size and structure of the upper axial blanket in order to get a zero or negative sodium void reactivity effect, -) the addition of scram rods based on passive activation, -) the addition of passive system of emergency cooling with sodium-air heat exchangers, -) a special in-vessel catcher envisaged under the core to catch and retain fragments of the core in case of core disruptive accident, and -) an improved earthquake resistance of all the structures. Such issues as possible options of fuel cycle, closing fuel cycle, transuranium element burning, disposal of plutonium being withdrawn from military programs, etc. are discussed as applied to the BN-800 reactor. Some economic considerations in general outline of the BN-800 unit are presented in the paper. It is important to note that the commissioning of the BN-800 reactor was included into the Federal Goal-Oriented Program - Development of nuclear energy-industrial complex of Russia for 2007-2010 and for perspective up to 2015 -, which was approved by the Russian Government in October 2006.

  19. High strength ferritic alloy

    International Nuclear Information System (INIS)

    A high strength ferritic steel is specified in which the major alloying elements are chromium and molybdenum, with smaller quantities of niobium, vanadium, silicon, manganese and carbon. The maximum swelling is specified for various irradiation conditions. Rupture strength is also specified. (U.K.)

  20. Study of decomposition and stabilization of splat-cooled cubic γ-phase U–Mo alloys

    International Nuclear Information System (INIS)

    Highlights: •The pure cubic γ-phase in splat-cooled U–Mo alloys are stabilized with 13–17 at.% Mo in the as-formed state. •Annealing at 800 °C stabilizes the cubic γ-phase. •The γ-phase U–Mo15 splat is stable in air and in hydrogen atmosphere and at room temperature. •The powder hydride UH3Mo0.18 with amorphous structure was formed under applying high hydrogen pressure of 80 bar. -- Abstract: U–Mo alloys were prepared by splat cooling technique and characterized by X-ray diffraction. The alloys with 11–12 at.% Mo show a stable γ°-phase, while those with 13–17 at.% Mo exhibit a pure γ-phase at room temperature. All the splats become superconducting with Tc in the range from 1.24 K (pure U splat) to 2.11 K (U–15 at.% Mo). The phase transformation and stabilization of γ-uranium phase in U–Mo alloys upon aging, annealing at 500 °C and 800 °C for time varying between 1 h and 144 h are described. Annealing at 500 °C leads to a decomposition of the γ-phase, while annealing at 800 °C has stabilized the initial γ-phase in U–Mo splat-cooled alloys. The γ-phase U–15 at.% Mo alloy is stable to hydrogen exposure at atmospheric pressure (1 bar) and at room temperature; it does not absorb any detectable amount of hydrogen. Exposed to high pressure (80 bar) of H2 gas it becomes hydride-powder (UH3Mo0.18) consisted of elongated particles of 1–2 mm revealing amorphous state. The hydrogen can be desorbed by heating to 500 °C in vacuum

  1. The in-situ Ti alloying of aluminum alloys and its application in A356 alloys

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This research has investigated the in-situ Ti alloying of aluminum alloys and its application to A356 alloys and wheels through the evaluation of microstructure and mechanical properties, The results showed that stable titanium content can be obtained by adding a small quantity of TiO2 into electrolyte of pure aluminum. Under this approach, a greater than 95% absorptivity of titanium was achieved, and the microstructure of the specimens was changed to fine equiaxed grains from coarse columnar grains in the pure aluminum. In comparison with the tradition A356 alloys and wheels, the corresponding microstructure in the testing A356 alloys and wheels was finer. Although the tensile strength was similar between the testing and the tradition A356 alloys and wheels, the ductility of the former (testing) is superior to that of the later (tradition), leading to an excellent combination of strength and ductility from the testing alloys and wheels.

  2. 奥林巴斯Stylus 800 Digital数码相机

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    这一款高达800万像素的最新数码相机,它外形小巧,在经典的μ mini DIGITAL基础上作了一些调整,使之操作手感更强。DIGITAL 800采用1/1.8英寸,800万有效像素CCD,3倍光学变焦,相当于35mm相机的38~114mm,属于一般家用的配置。2.5英寸的液晶显示屏,分辨率达到21.5万像素。采用xD卡,可充式锂电池。

  3. Advanced ordered intermetallic alloy deployment

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.T.; Maziasz, P.J.; Easton, D.S. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    The need for high-strength, high-temperature, and light-weight materials for structural applications has generated a great deal of interest in ordered intermetallic alloys, particularly in {gamma}-based titanium aluminides {gamma}-based TiAl alloys offer an attractive mix of low density ({approximately}4g/cm{sup 3}), good creep resistance, and high-temperature strength and oxidation resistance. For rotating or high-speed components. TiAl also has a high damping coefficient which minimizes vibrations and noise. These alloys generally contain two phases. {alpha}{sub 2} (DO{sub 19} structure) and {gamma} (L 1{sub 0}), at temperatures below 1120{degrees}C, the euticoid temperature. The mechanical properties of TiAl-based alloys are sensitive to both alloy compositions and microstructure. Depending on heat-treatment and thermomechanical processing, microstructures with near equiaxed {gamma}, a duplex structure (a mix of the {gamma} and {alpha}{sub 2} phases) can be developed in TiAl alloys containing 45 to 50 at. % Al. The major concern for structural use of TiAl alloys is their low ductility and poor fracture resistance at ambient temperatures. The purpose of this project is to improve the fracture toughness of TiAl-based alloys by controlling alloy composition, microstructure and thermomechanical treatment. This work is expected to lead to the development of TiAl alloys with significantly improved fracture toughness and tensile ductility for structural use.

  4. Hot deformation behavior of TC18 titanium alloy

    Directory of Open Access Journals (Sweden)

    Jia Bao-Hua

    2013-01-01

    Full Text Available Isothermal compression tests of TC18 titanium alloy at the deformation temperatures ranging from 25°C to 800°C and strain rate ranging from 10-4 to 10-2 s-1 were conducted by using a WDW-300 electronic universal testing machine. The hot deformation behavior of TC18 was characterized based on an analysis of the true stress-true strain curves of TC18 titanium alloy. The curves show that the flow stress increases with increasing the strain rate and decreases with increasing the temperature, and the strain rate play an important role in the flow stress when increasing the temperatures. By taking the effect of strain into account, an improved constitutive relationship was proposed based on the Arrhenius equation. By comparison with the experimental results, the model prediction agreed well with the experimental data, which demonstrated the established constitutive relationship was reliable and can be used to predict the hot deformation behavior of TC18 titanium alloy.

  5. 800例活性IUD临床效果观察

    Institute of Scientific and Technical Information of China (English)

    熊真如; 刘如

    2008-01-01

    目的 探讨活性IUD的避孕效果.方法 对妇科门诊800例放置活性IUD的育龄妇女进行两年临床观察与随访.结果 800例活性IUD放置24个月续存率达96.5%,脱落率0.5%,带器妊娠率1%,因症取出率2%.结论 活性IUD取代惰性IUD能明显提高避孕效果.

  6. Structural evolution of Cu{sub (1−X)}Y{sub X} alloys prepared by mechanical alloying: Their thermal stability and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Mula, Suhrit, E-mail: smulafmt@iitr.ernet.in [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Setman, Daria [Physics of Nanostructured Materials, University of Vienna, Boltzmanngasse 5, A-1090 Wien (Austria); Youssef, Khaled [Department of Materials Science and Technology, Qatar University, P.O. Box 2713, Doha (Qatar); Scattergood, R.O.; Koch, Carl C [Department of Materials Science and Engineering, NC State University, Raleigh, NC 27695 (United States)

    2015-04-05

    Highlights: • Metastable solid solutions were prepared from Cu–Y nonequilibrium compositions by mechanical alloying. • Gibbs free energy change as per Miedema’s model confirms the formation of metastable alloys. • High Y content alloys showed high thermal stability during extensive annealing at high temperatures. • Stabilized alloys showed very high hardness and improved yield strength. • Mechanisms of high thermal stability and improved mechanical properties were discussed. - Abstract: In the present study, an attempt has been made to synthesize copper based disordered solid solutions by mechanical alloying (MA) of non-equilibrium compositions. The blended compositions of Cu–1% Y, Cu–3% Y, Cu–5% Y and Cu–7.5% Y (at.%) (all the compositions will be addressed as % only hereafter until unless it is mentioned) were ball-milled for 8 h, and then annealed at different temperatures (200–800 °C) for different length of duration (1–5 h) under high purity argon + 2 vol.% H{sub 2} atmosphere. X-ray diffraction (XRD) analysis and Gibbs free energy change calculation confirm the formation of disordered solid solution (up to 7.5%) of Y in Cu after milling at a room temperature for 8 h. The XRD grain size was calculated to be as low as 7 nm for 7.5% Y and 22 nm for 1% Y alloy. The grain size was retained within 35 nm even after annealing for 1 h at 800 °C. Transmission electron microscopy (TEM) analysis substantiates the formation of ultra-fine grained nanostructures after milling. Microhardness value of the as-milled samples was quite high (3.0–4.75 GPa) compared to that of pure Cu. The hardness value increased with increasing annealing temperatures up to 400 °C for the alloys containing 3–7.5% Y, and thereafter it showed a decreasing trend. The increase in the hardness after annealing is attributed to the formation of uniformly distributed ultrafine intermetallic phases in the nanocrystalline grains. The stabilization effect is achieved due to

  7. Filler metal alloy for welding cast nickel aluminide alloys

    Science.gov (United States)

    Santella, M.L.; Sikka, V.K.

    1998-03-10

    A filler metal alloy used as a filler for welding cast nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and cast in copper chill molds. 3 figs.

  8. Filler metal alloy for welding cast nickel aluminide alloys

    Energy Technology Data Exchange (ETDEWEB)

    Santella, Michael L. (Knoxville, TN); Sikka, Vinod K. (Oak Ridge, TN)

    1998-01-01

    A filler metal alloy used as a filler for welding east nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and east in copper chill molds.

  9. Evaluation of Microstructure and Mechanical Properties of Nano-Y2O3-Dispersed Ferritic Alloy Synthesized by Mechanical Alloying and Consolidated by High-Pressure Sintering

    Science.gov (United States)

    Karak, Swapan Kumar; Dutta Majumdar, J.; Witczak, Zbigniew; Lojkowski, Witold; Ciupiński, Łukasz; Kurzydłowski, K. J.; Manna, Indranil

    2013-06-01

    In this study, an attempt has been made to synthesize 1.0 wt pct nano-Y2O3-dispersed ferritic alloys with nominal compositions: 83.0 Fe-13.5 Cr-2.0 Al-0.5 Ti (alloy A), 79.0 Fe-17.5 Cr-2.0 Al-0.5 Ti (alloy B), 75.0 Fe-21.5 Cr-2.0 Al-0.5 Ti (alloy C), and 71.0 Fe-25.5 Cr-2.0 Al-0.5 Ti (alloy D) steels (all in wt pct) by solid-state mechanical alloying route and consolidation the milled powder by high-pressure sintering at 873 K, 1073 K, and 1273 K (600°C, 800°C, and 1000°C) using 8 GPa uniaxial pressure for 3 minutes. Subsequently, an extensive effort has been undertaken to characterize the microstructural and phase evolution by X-ray diffraction, scanning and transmission electron microscopy, and energy dispersive spectroscopy. Mechanical properties including hardness, compressive strength, Young's modulus, and fracture toughness were determined using micro/nano-indentation unit and universal testing machine. The present ferritic alloys record extraordinary levels of compressive strength (from 1150 to 2550 MPa), Young's modulus (from 200 to 240 GPa), indentation fracture toughness (from 3.6 to 15.4 MPa√m), and hardness (from13.5 to 18.5 GPa) and measure up to 1.5 through 2 times greater strength but with a lower density (~7.4 Mg/m3) than other oxide dispersion-strengthened ferritic steels (ferritic matrix useful for grain boundary pinning and creep resistance.

  10. Effect Of Process Parameters On Mechanical Properties Of Friction Stir.Welded Joint Of Two Similar &Dissimilar Al-Alloys

    Directory of Open Access Journals (Sweden)

    Umasankar Das,

    2015-09-01

    Full Text Available Friction Stir Welding (FSW is an advance joining process for different similar and dissimilar materials. It is commonly used for joining of Aluminum alloys. However it is necessary to overcome some challenges for its wide-spread uses. Tool design and the selection of process parameters are critical issues in the usage of this process. This study focuses on the process parameters that is required for producing effective friction stir welding of two similar aluminum alloys (AA6101T6 to AA6101T6 and dissimilar Aluminum alloys (AA6101T6 alloy to AA6351T6 . Three different tool diameters such as 20 mm, 25 mm and 30 mm with three different tool rotational speeds such as 600 rpm, 800 rpm and 1200 rpm have been used to weld the joints. The welded samples were tested for mechanical properties as well as microstructure. It was observed that 30 mm tool gives better weld quality for friction stir welding of similar aluminum alloy but 25 mm tool with 1200 rpm rotational speed gave satisfactory weld quality for friction stir welding of dissimilar aluminum alloys. It is one of the important welding process that can adopted for welding of aluminum alloys with excellent mechanical properties. The results were confirmed by further experiments.

  11. Clinical Evaluation of BS800 automatic biochemical analyzer%BS800全自动生化分析仪临床应用评价

    Institute of Scientific and Technical Information of China (English)

    刘清华; 张志伟; 成希; 王敏; 李燕秀; 余岱洋; 吴秀娟; 刘春兰

    2012-01-01

      目的:对新购进 BS-800全自动生化分析仪进行精密度、携带污染率的性能评价.方法:按照美国临床实验室标准化委员会(NCCLS)EP10-T2方法学原理,采用四川新成公司的丙氨酸氨基转移酶(ALT)、葡萄糖(GLU)、尿素氮(BUN)、肌酐(Cr)4种试剂,按 NCCLS 文件的要求在BS-800全自动生化分析仪上对其批内精密度(S批内)、总精密度(S总)以及交叉污染率进行实验评价.结果:该仪器批内CV均在2%左右,总CV值<5%,经X2检验均可接受,仪器平均交叉污染率为0.04%~0.07%,交叉污染率很低,符合临床要求.结论: BS-800全自动生化分析仪具有良好的分析精密度,交叉污染率低,适用范围广,对试剂要求不高,能满足实验室的日常检验要求,适合大中型医院使用.%  Objective:precision, carryover performance evaluation of newly purchased BS-800 automatic biochemical analyzer. Method:In accordance with the methodological principle of the American Clinical Laboratory Standards Committee (NCCLS) EP10-T2, Sichuan into a new company alanine amino transferase enzyme (ALT), glucose (GLU), blood urea nitrogen (BUN), creatinine (Cr) 4 reagents, NCCLS document requirements in the BS-800 automatic biochemistry analyzer within-run precision (S intra) and inter-assay precision (S batch) as well as cross-contamination rate for the experimental evaluation. results:The instrument batch CV were about 2%, inter-assay CV<5%, acceptable by the X2 test instrument average cross contamination rate of 0.04% to 0.07%, the low rate of cross-contamination, to meet the clinical requirements. conclusions: BS-800 automatic biochemical analyzer has good analytical precision, low cross-contamination, and for a wide range of inspection requirements to meet the day-to-day laboratory reagent less demanding, suitable for large and medium-sized hospitals.

  12. High-temperature Titanium Alloys

    Directory of Open Access Journals (Sweden)

    A.K. Gogia

    2005-04-01

    Full Text Available The development of high-temperature titanium alloys has contributed significantly to the spectacular progress in thrust-to-weight ratio of the aero gas turbines. This paper presents anoverview on the development of high-temperature titanium alloys used in aero engines and potential futuristic materials based on titanium aluminides and composites. The role of alloychemistry, processing, and microstructure, in determining the mechanical properties of titanium alloys is discussed. While phase equilibria and microstructural stability consideration haverestricted the use of conventional titanium alloys up to about 600 "C, alloys based on TiPl (or,, E,AINb (0, TiAl (y, and titaniumltitanium aluminides-based composites offer a possibility ofquantum jump in the temperature capability of titanium alloys.

  13. Re-recognition of Training Concepts and Methods of 800-meter Race%对800米跑项目训练理念及方法的再认识

    Institute of Scientific and Technical Information of China (English)

    刘琳

    2015-01-01

    近年来我国800米跑项目的发展与国外对比还处于相对落后的状态,国际比赛中的成绩也证明了我国800米跑运动员与国外运动员的差距.本文通过对现阶段基层学校800米训练方法进行整理、分析,总结其与现代800米跑项目发展趋势及项目特征相悖之处,提出相应建议,以期提高基层学校800米跑项目成绩,进而为提高我国800米跑项目竞技水平提供理论参考.

  14. KMQ-800型矿用连续牵引车的应用%Application on KMQ-800 Type Continuous Tractor for Mine

    Institute of Scientific and Technical Information of China (English)

    卢国斌

    2008-01-01

    介绍了KMQ-800型矿用连续牵引车的结构原理和设计理念,以及应用情况,阐述了一种适合煤矿井下的、新型的、安全高效的井下辅助运输系统,探讨了该设备对我国煤矿辅助运输技术进步的重大意义.

  15. 3 800 m3耙吸挖泥船的HVAC设计%HVAC design for a 3 800 m3 trailing suction dredger

    Institute of Scientific and Technical Information of China (English)

    戴菁; 赵骊; 陈维茂

    2007-01-01

    挖泥船的需求量与日俱增,逐渐形成系列船型.通过介绍3 800 m3耙吸挖泥船的HVAC设计系统,与以往挖泥船型比较,以及用户的评价,指出该船的空调系统设计思想和方法上的优点,为后续船提供了有益的参考.

  16. 复相钢CP800焊缝冷裂纹敏感性研究%COLD CRACKING SUSCEPTIBILITY OF WELDED JOINT OF CP800 STEEL

    Institute of Scientific and Technical Information of China (English)

    韩坤; 李清山; 李健; 孙慧珺; 张梅; 徐云峰

    2012-01-01

    The butt joint, Y shape butt joint, tee joint and control thermal severity (CTS) of the welded joint (lap joint) were studied after the gas shielded arc welding for CP800 steel. The macroscopic morphology, microstructure and properties of different welding points were measured to study the weld ability and cold cracking susceptibility of CP800 steel. The test results showed that the steel was appropriate for various welding forms of automobile parts due to the lower weld cold cracking susceptibility. The microstructure of heat affected zone was granular ferrite, bainite and a small amount of lath bainite, which were well distributed and the fusion was good. The hardness distribution of the four different welding forms was similar and the maximum hardness value was 320 HV, lower than 350 HV. The impact toughness of base metal, heat affected zone and fusion zone of Y shape butt joint was higher than 23 J, and the fracture surface was dimple fracture under the scanning electron microscope.%采用气体保护焊对试验钢CP800分别进行对接、斜Y、T型(角接)、CTS(搭接)焊接,测试分析不同焊接接头形式下的宏观形貌、微观组织和性能的变化,以研究CP800钢的可焊性和冷裂纹敏感性.实验结果表明:试验钢适用于各种焊接形式下的汽车结构件,具有很低的焊缝冷裂纹敏感性.焊接热影响区的组织为粒状铁素体、贝氏体以及少量的板条贝氏体,分布均匀,焊缝熔合良好.4种不同焊接方式下的焊缝硬度分布一致,最高硬度值为320 HV,小于350 HV.斜Y坡口对接接头处的母材、热影响区以及熔合区的冲击性能均大于23 J,其断口形貌均为韧窝形状.

  17. 联想智能手机——乐Phone K800%Le Phone K800——lenovo Smart CP

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    英特尔公司与联想集团共同宣布,联想首款Intel Inside智能手机——联想乐Phone K800在中国市场正式上市。这是两家公司基于英特尔架构,推动移动计算协同创新的重要里程碑性成果,开辟了智能手机的全新门类。

  18. Rare earth ferrosilicon alloy

    International Nuclear Information System (INIS)

    In order to obtain RE ferrosilicon alloy with good quality and competitive price, it is essential that proper choice of raw materials, processing technology and equipments should be made based on the characteristics of Bai-Yun-Ebo mineral deposits. Experimental work and actual production practice indicate that pyrometallurgical method is suitable for the extraction and isolation of the rare earths and comprehensive utilization of the metal values contained in the feed material is capable of reducing cost of production of RE ferrosilicon alloy. In the Bai-Yun-Ebo deposit, the fluorite type medium lean ore (with respect to iron content) makes a reserve of considerable size. The average content of the chief constituents are given

  19. High-temperature Titanium Alloys

    OpenAIRE

    A.K. Gogia

    2005-01-01

    The development of high-temperature titanium alloys has contributed significantly to the spectacular progress in thrust-to-weight ratio of the aero gas turbines. This paper presents anoverview on the development of high-temperature titanium alloys used in aero engines and potential futuristic materials based on titanium aluminides and composites. The role of alloychemistry, processing, and microstructure, in determining the mechanical properties of titanium alloys is discussed. While phase eq...

  20. Multicomponent and High Entropy Alloys

    Directory of Open Access Journals (Sweden)

    Brian Cantor

    2014-08-01

    Full Text Available This paper describes some underlying principles of multicomponent and high entropy alloys, and gives some examples of these materials. Different types of multicomponent alloy and different methods of accessing multicomponent phase space are discussed. The alloys were manufactured by conventional and high speed solidification techniques, and their macroscopic, microscopic and nanoscale structures were studied by optical, X-ray and electron microscope methods. They exhibit a variety of amorphous, quasicrystalline, dendritic and eutectic structures.

  1. The fit of four parameter logistic calibration of DXI 800 chemiluminescence analyzer by Origin software%采用Origin软件计算DXI 800发光仪的四参数logistic定标数据

    Institute of Scientific and Technical Information of China (English)

    王强; 马小红; 翁秀妹

    2014-01-01

    Objective To fit 4 parameter logistic calibration of DXI 800 chemiluminescence analyzer by Origin software and compare the datum difference between Origin and DXI 800,and to investigate the calculation possibility of unknown results of DXI 800 by Origin software.Methods The calibration results of testosterone,total thyroxine, estradiol,troponin I,thyrotropic hormone,carcino-embryonic antigen and progesterone were collected and fit by Origin software,and the calculation results with the original results of DXI 800 system were analyzed comparatively.Results The calculation results of Origin software were very close to the original results of DXI 800,and mean bias was from-0.85% to 1 .68%.Conclusions Origin software is suitable for the calculation of unknown results of DXI 800 chemiluminescence analyzer.%目的:采用Origin软件拟合DXI 800发光仪的四参数logistic定标数据,比较其与DXI 800计算的数据差异,探讨采用Origin软件计算DXI 800未知数据的可能性。方法选择睾酮、总甲状腺素、雌二醇、肌钙蛋白I、促甲状腺激素、癌胚抗原和孕酮的定标数据,采用Origin软件拟合四参数logistic计算结果,与DXI 800发光仪计算的结果比较。结果采用 Origin 软件计算的结果与 DXI 800计算的结果基本一致,平均偏倚介于-0.85%~1.68%之间。结论可以采用Origin软件计算DXI 800发光仪的未知结果。

  2. Pareto-optimal alloys

    DEFF Research Database (Denmark)

    Bligaard, Thomas; Johannesson, Gisli Holmar; Ruban, Andrei;

    2003-01-01

    Large databases that can be used in the search for new materials with specific properties remain an elusive goal in materials science. The problem is complicated by the fact that the optimal material for a given application is usually a compromise between a number of materials properties and the ......, the Pareto-optimal set, to determine optimal alloy solutions for the compromise between low compressibility, high stability, and cost....

  3. Alloy catalyst material

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a novel alloy catalyst material for use in the synthesis of hydrogen peroxide from oxygen and hydrogen, or from oxygen and water. The present invention also relates to a cathode and an electrochemical cell comprising the novel catalyst material, and the process use...... of the novel catalyst material for synthesising hydrogen peroxide from oxygen and hydrogen, or from oxygen and water....

  4. 7 CFR 800.39 - Suspension or revocation of registration for cause.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Suspension or revocation of registration for cause... AGRICULTURE GENERAL REGULATIONS Registration § 800.39 Suspension or revocation of registration for cause. (a... Instituted by the Secretary under Various Statutes (7 CFR, 1.130 through 1.151). Prior to formal...

  5. 31 CFR 19.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false What are the causes for debarment? 19... DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 19.800 What are the causes for debarment? We may debar... agreement or transaction; (c) Any of the following causes: (1) A nonprocurement debarment by any...

  6. Orbital and millennial Antarctic climate variability over the past 800,000 years

    DEFF Research Database (Denmark)

    Jouzel, J.; Masson-Delmotte, V.; Cattani, O.;

    2007-01-01

    A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage 20.2, 800,000 years ago. Experiments performed with an atmospheric general circulation model including wa...

  7. 75 FR 66769 - Draft Compliance Policy Guide Sec. 690.800 Salmonella

    Science.gov (United States)

    2010-10-29

    ...) that appeared in the Federal Register of August 2, 2010 (75 FR 45130). In the document, FDA requested... In the Federal Register of August 2, 2010 (75 FR 45130), FDA published a notice of availability of a... HUMAN SERVICES Food and Drug Administration Draft Compliance Policy Guide Sec. 690.800 Salmonella...

  8. 78 FR 42526 - Compliance Policy Guide Sec. 690.800 Salmonella

    Science.gov (United States)

    2013-07-16

    ... statutes and regulations. In the Federal Register of August 2, 2010 (75 FR 45130), we announced the... (75 FR 66769), we published a notice extending the comment period until December 31, 2010. We received... HUMAN SERVICES Food and Drug Administration Compliance Policy Guide Sec. 690.800 Salmonella in Food...

  9. System Design and Research of Yunnan-Guangdong ±800 kV UHVDC Project

    Institute of Scientific and Technical Information of China (English)

    RAO Hong

    2012-01-01

    The ±800 kV ultra high voltage direct current (UHVDC) transmission system is an extraordinary challenge to system design and equipment manufacture. China Southern Power Grid Company (CSG) organized research and design for the construction of Yunnan-Guangdong ±800 kV UHVDC project (YG UHVDC project), and got large technical breakthroughs and advanced technologies for ±800 kV UHVDC transmission systems. These advanced technologies include power system stability, main electrical wiring, overvoltage and insulation coordination, external insulation, electromagnetic environment, control and protection, and arrangement of the main equipments. Meanwhile, CSG led the researches on specification of main equipments, such as converter valve, converter transformer, dry-type smooth reactor and others involved in the whole process management of equipment supervisions. The YG UHVDC project was put into commercial operation in 2010 as the first pilot ±800 kV UHVDC project in the world. The whole system operated in a stable and smooth manner, and the UHVDC equipment and control systems passed the test under the practical operation in CSG bulk power system, which shows that the design and research objectives were achieved.

  10. 8 CFR 204.313 - Filing and adjudication of a Form I-800.

    Science.gov (United States)

    2010-01-01

    ... service provider's plan for post-placement duties, as specified in 22 CFR 96.50; and (5) If the child may... has given the notice contemplated by article 5(c) of the Convention, shall constitute prima facie... jurisdiction under 8 CFR 204.308(b) to adjudicate the Form I-800, together with the evidence specified in...

  11. Pre-Clovis mastodon hunting 13,800 years ago at the Manis site, Washington

    DEFF Research Database (Denmark)

    Waters, Michael R; Stafford, Thomas W; McDonald, H Gregory;

    2011-01-01

    The tip of a projectile point made of mastodon bone is embedded in a rib of a single disarticulated mastodon at the Manis site in the state of Washington. Radiocarbon dating and DNA analysis show that the rib is associated with the other remains and dates to 13,800 years ago. Thus, osseous projec...

  12. 76 FR 2605 - Airworthiness Directives; Rolls-Royce plc RB211-Trent 800 Series Turbofan Engines

    Science.gov (United States)

    2011-01-14

    ... Register published on April 11, 2000 (65 FR 19477-78). Discussion The European Aviation Safety Agency (EASA... Order 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR... Directives; Rolls-Royce plc RB211-Trent 800 Series Turbofan Engines AGENCY: Federal Aviation...

  13. 75 FR 15321 - Airworthiness Directives; Rolls-Royce plc RB211-Trent 800 Series Turbofan Engines

    Science.gov (United States)

    2010-03-29

    ... Register on January 5, 2010 (75 FR 264). That NPRM proposed to correct an unsafe condition for the... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a significant...; AD 2010-06-14] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc RB211-Trent 800...

  14. 31 CFR 800.403 - Deferral, rejection, or disposition of certain voluntary notices.

    Science.gov (United States)

    2010-07-01

    ... REGULATIONS PERTAINING TO MERGERS, ACQUISITIONS, AND TAKEOVERS BY FOREIGN PERSONS Notice § 800.403 Deferral... acquisition by Company A, a foreign person, of the entire interest in Company X, a U.S. business. The notice... foreign person, and Corporation X, a company that is owned and controlled by U.S. nationals, with...

  15. 7 CFR 800.85 - Inspection of grain in combined lots.

    Science.gov (United States)

    2010-01-01

    ... for grain in a combined lot shall, subject to the provisions of paragraphs (e) through (g) of this... shall be determined in accordance with the instructions. (e) Infested grain. If the grain in a combined... 7 Agriculture 7 2010-01-01 2010-01-01 false Inspection of grain in combined lots. 800.85...

  16. 78 FR 42701 - Improving Public Safety Communications in the 800 MHz Band

    Science.gov (United States)

    2013-07-17

    ... (Commission) modifies the freeze on new authorizations in the Business and Industrial Land Transportation (B... file an application for a new authorization in any given National Public Safety Planning Advisory... the 800 MHz rebanding process. DATES: Effective August 16, 2013. FOR FURTHER INFORMATION...

  17. 7 CFR 800.185 - Duties of official personnel and warehouse samplers.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Duties of official personnel and warehouse samplers... official personnel and warehouse samplers. (a) General. Official personnel and warehouse samplers shall... of § 800.161. (d) Scope of operations. Official personnel and warehouse samplers shall operate...

  18. Laidoneri-Savisaare villa hinnati juba 2003. aastal 800 000 kroonile / Martti Kass

    Index Scriptorium Estoniae

    Kass, Martti

    2005-01-01

    Edgar Savisaare firma ostetud suvila Keila-Joal oli 2003. aastal Arco Vara hinnangul väärt 800 000 krooni. Kinnisvaraekspertide hinnangul on Keila-Joa kinnisvara väärtus viimaste aastatega mitu korda suurenenud. Lisa: Ojulandi ja Käo maja hinnati 3,25 miljonile

  19. Tallinna lähedale kerkib 800 miljonit maksev elektrijaam / Martin Hanson

    Index Scriptorium Estoniae

    Hanson, Martin, 1984-

    2005-01-01

    Ilmunud ka: Delovõje Vedomosti 21. sept. lk. 5. Eesti Energia nõukogu esimehe Urmas Sõõrumaa elukaaslase isa Priit Maran rajab Tallinna külje alla Väole 800 miljonit krooni maksvat elektrijaama. Vt. samas: Suurfirmad on kaalunud oma jõujaama

  20. 7 CFR 800.7 - Information about the Service, Act, and regulations.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Information about the Service, Act, and regulations... AGRICULTURE GENERAL REGULATIONS Administration § 800.7 Information about the Service, Act, and regulations. Information about the Grain Inspection, Packers and Stockyards Administration, Service, Act,...

  1. 45 CFR 2519.800 - What are the evaluation requirements for Higher Education programs?

    Science.gov (United States)

    2010-10-01

    ... (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE HIGHER EDUCATION INNOVATIVE PROGRAMS FOR COMMUNITY SERVICE Evaluation Requirements § 2519.800 What are the evaluation requirements for Higher Education... 45 Public Welfare 4 2010-10-01 2010-10-01 false What are the evaluation requirements for...

  2. Oligocrystalline shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ueland, Stian M.; Chen, Ying; Schuh, Christopher A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2012-05-23

    Copper-based shape memory alloys (SMAs) exhibit excellent shape memory properties in single crystalline form. However, when they are polycrystalline, their shape memory properties are severely compromised by brittle fracture arising from transformation strain incompatibility at grain boundaries and triple junctions. Oligocrystalline shape memory alloys (oSMAs) are microstructurally designed SMA structures in which the total surface area exceeds the total grain boundary area, and triple junctions can even be completely absent. Here it is shown how an oligocrystalline structure provides a means of achieving single crystal-like SMA properties without being limited by constraints of single crystal processing. Additionally, the formation of oSMAs typically involves the reduction of the size scale of specimens, and sample size effects begin to emerge. Recent findings on a size effect on the martensitic transformation in oSMAs are compared and a new regime of heat transfer associated with the transformation heat evolution in these alloys is discussed. New results on unassisted two-way shape memory and the effect of loading rate in oSMAs are also reported. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Aluminum alloy impact sparkling

    Directory of Open Access Journals (Sweden)

    M. Dudyk

    2008-08-01

    Full Text Available The cast machine parts are widely used in many branches of industry. A very important issue is gaining the appropriate knowledge relating to the application of castings in places of explosion risks including but not limited to mining, chemical industry and rescue works. A possibility of explosion risks occurrence following the impact sparkling of the cast metal parts is still not solved problem in scientific research. In relation to this issue, in this article, the results of the study are presented, and relating to the tendency to impact sparkling of the aluminium alloys used in machine building. On the grounds of the results obtained, it was demonstrated that the registered impact sparkles bunches of feathers from the analyzed alloys: AlSi7Mg, (AK7; AlSi9Mg, (AK9; AlSi6Cu4, (AK64 and AlSi11, (AK11 show significant differences between each other. The quantitative analysis of the temperature distribution and nuclei surface area performed on the example of the alloy AK9 (subjected to defined period of corrosion allows for the statement that they are dangerous in conditions of explosion risk. Following this fact, designers and users of machine parts made from these materials should not use them in conditions where the explosive mixtures occur.

  4. Some features of beryllium corrosion behavior in Be-liquid Li-V-4Ti-4Cr alloy system

    International Nuclear Information System (INIS)

    Recent experimental results on beryllium corrosion behavior in a V-4Ti-4Cr alloy, liquid lithium static system during testing for 200-500 h at temperatures from 600 to 800 deg. C are presented. The influence of test conditions (temperature, duration and lithium purity) and beryllium characteristics (microstructure, grain size and chemical composition) on weight loss of beryllium and penetration of lithium into beryllium are discussed. Results of compressive tests for beryllium specimens before and after corrosion testing are also introduced

  5. Sulfidation, down time corrosion and corrosion assisted cracking on high alloyed materials in synthetic coal gasifier environments

    Energy Technology Data Exchange (ETDEWEB)

    Huijbregts, W.M.M.; Kokmeijer, E.; Van Zuilen, H.G. (KEMA Inspecties en Materialen, Arnhem (Netherlands))

    1993-01-01

    The research on the title subject is aimed at finding suitable materials for heat exchangers in coal gasification installations. Some materials are tested regarding their sensitivity for the title corrosion types under coal gasification conditions. The tested materials are AISI 310, Sanicro 28, AC66, Alloy 800, chromium diffusion coatings and Inconel 625. To investigate and qualify the corrosion layers use is made of light and electron microscopy techniques

  6. Influence of heat treatment on the microstructure and mechanical properties of DZ951 alloy

    Institute of Scientific and Technical Information of China (English)

    XIA Pengcheng; YU Jingjiang; SUN Xiaofeng; GUAN Hengrong; HU Zhuangqi

    2008-01-01

    DZ951 directionally solidified nickel-base superalloy is mainly strengthened by y phase.Regularly aligned cuboidal and bimodal γ precipitates were attained by two heat treatments.The effect of microstructure on the mechanical properties of DZ951 alloy has been investigated.The results indicate that MC carbide changes to little blocks during aging treatment at 1050℃ (HT1).MC carbide partly degrades into M23c6 and there is a layer of γ around the carbide during aging treatment at 115℃ (HT2),which is beneficial to the elongation of DZ951 alloy.Small γ volume fraction and the uneven deformation structure are contributed to low mechanical propexties of the as-cast alloy.HT1 alloy has a better stress rupture life at 1100℃50 MPa and yield stress at 20℃,800℃ and 1100℃,which is attributed to regularly aligned cuboidal γ phase and even deformation structure.HT2 alloy has a good combination of strength and ductility.This arises fi'om the bimodal γ precitates and the degeneration of MC carbide.

  7. Evaluation of Ni-Cr-base alloys for SOFC interconnect applications

    Science.gov (United States)

    Yang, Zhenguo; Xia, Guan-Guang; Stevenson, Jeffry W.

    To further understand the suitability of Ni-Cr-base alloys for solid oxide fuel cell (SOFC) interconnect applications, three commercial Ni-Cr-base alloys, Haynes 230, Hastelloy S and Haynes 242 were selected and evaluated for oxidation behavior under different exposure conditions, scale conductivity and thermal expansion. Haynes 230 and Hastelloy S, which have a relatively high Cr content, formed a thin scale mainly comprised of Cr 2O 3 and (Mn,Cr,Ni) 3O 4 spinels under SOFC operating conditions, demonstrating excellent oxidation resistance and a high scale electrical conductivity. In contrast, a thick double-layer scale with a NiO outer layer above a chromia-rich substrate was grown on Haynes 242 in moist air or at the air side of dual exposure samples, indicating limited oxidation resistance for the interconnect application. With a face-centered-cubic (FCC) substrate, all three alloys possess a coefficient of thermal expansion (CTE) that is higher than that of candidate ferritic stainless steels, e.g. Crofer22 APU. Among the three alloys, Haynes 242, which is heavily alloyed with W and Mo and contains a low Cr content, demonstrated the lowest average CTE at 13.1 × 10 -6 K -1 from room temperature to 800 °C, but it was also observed that the CTE behavior of Haynes 242 was very non-linear.

  8. The influence of thermomechanical processing on microstructural evolution of Ti600 titanium alloy

    International Nuclear Information System (INIS)

    Highlights: → Temperature and strain rate have great influence on the microstructure features. → The formation of sub-grain and dislocation wall is the typically microstructure features observed in the β single-phase. → The elongated lamellar α platelets kinked increasingly and break up under the α + β processing conditions. → The softening mechanisms of the Ti600 alloy hot compressed at 1000-1100 deg. C are mainly dynamic recovery. - Abstract: The influences of thermomechanical processing on microstructural evolution of Ti600 alloy were studied in the temperature range of 800-1100 deg. C, and at the strain rate of 0.001-10 s-1. During the isothermal compression experiment, the flow stress-strain curves are examined in the β single-phase and in the α + β two-phase regions. The results show that the thermomechanical processing parameters have significant influences on the microstructure of Ti600 alloy, especially on the grain size, morphologies of α phase. Moreover, the microstructural evolution was analyzed by optical microstructure (OM) and transmission electron microscopy (TEM). It was found that typical of dynamic recovery and dynamic recrystallization phenomenon occurring in the thermomechanical processing. These results will optimize the microstructural control for hot working of Ti600 alloy and deepen the understanding of the flow softening mechanism of near-α titanium alloy.

  9. Experimental investigation of emissivity of aluminum alloys and application of multispectral radiation thermometry

    International Nuclear Information System (INIS)

    Experiments were first conducted to measure the emissivity values of a variety of aluminum alloys at 600, 700, and 800 K. The effects of wavelength, temperature, alloy composition, and heating time on emissivity were investigated. Multispectral radiation thermometry (MRT) with linear emissivity models (LEM) and log-linear emissivity models (LLE) were then applied to predict surface temperature. Parametric influences of wavelength number, heating time and order of emissivity models were examined. Results show that the spectral emissivity decreases with increasing wavelength and increases with increasing temperature. A stronger alloy effect is evident at higher temperature. The spectral emissivity reaches steady state after the first hour heating due to the surface oxidation becoming fully-developed. Half of the temperature predictions by MRT emissivity models provide the absolute temperature error under 10% and quarter of the results are under 5%. Increasing the order of emissivity model and increasing the number of wavelengths cannot improve temperature measurement accuracy. Overall, LLE models show higher accuracy than LEM models. The first-order and second-order LLE models and the first-order LEM model give good results most frequently and provide the best compensation for different alloys, the number of wavelengths, and temperatures. - Highlights: → Emissivity behaviors of aluminum alloys were investigated experimentally. → Multispectral radiation thermometry (MRT) were examined. → Three MRT emissivity models perform well on temperature prediction.

  10. Contribution to studies of an industrial alloy uranium-niobium with 6% by weight niobium

    International Nuclear Information System (INIS)

    This uranium alloy with 6% by weight niobium (U-6% Nb) obtained by fusion in an induction furnace with thermal gradient directed solidification in a mould, exhibits a small amount of minor segregation (less than 1% by weight), little major segregation and small diameter isolated aggregations. Microsegregation can be eliminated by a homogenization heat treatment (8 hours at 11000C). The hot forming temperature for this alloy lies between 800 and 9000C. In this temperature range, the deformation resistance is low and the deformation capacity high. Laminated tempered U-6%Nb alloy is of very low hardness (150 Vickers) and has a low elastic limit (180 MPa) at 0.2% suitable for cold forming. Annealing performed at temperatures less than 3000C enhance the strength of this alloy when it is in a laminated tempered state without significantly diminishing its ductility properties. Finally, U-6%Nb alloy in the laminated tempered state and welded by electron bombardment does not exhibit differential rupture and retains satisfactory mechanical properties

  11. Interfacial reaction kinetics of coated SiC fibers with various titanium alloys

    Science.gov (United States)

    Gundel, D. B.; Wawner, F. E.

    1991-01-01

    The kinetics of the reaction between the silicon carbide fibers and the titanium-based alloy matrix was investigated at temperatures from 800 to 1000 C for several titanium-based alloys (including Ti-1100 alloy and BETA 21S) and unalloyed Ti, reinforced with coated silicon carbide fiber SCS-6. The reaction zone growth kinetics was studied by exposing vacuum encapsulated samples to temperatures from 700 to 1000 C for times up to 150 hrs, followed by SAM observations of samples which were polished perpendicular to the fiber axis and etched. It was found that the reaction zone growth kinetics of the alpha (hcp) and beta (bcc) phases of unalloyed titanium reacting with SCS-6 fibers exhibited different values of the apparent activation energy and of the preexponential factor. Additions of other metals to Ti was found to slow down the reaction kinetics. Among the alloys studied, the Ti-1100 was the slowest reacting conventional alloy and the Ti-14Al-21Nb (in wt pct) was the slowest overall.

  12. The influence of thermomechanical processing on microstructural evolution of Ti600 titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Han Yuanfei [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an 710072 (China); Zeng Weidong, E-mail: zengwd@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an 710072 (China); Qi Yunlian; Zhao Yongqing [Northwest Institute for Nonferrous Metal Research, Xi' an 710016 (China)

    2011-11-15

    Highlights: {yields} Temperature and strain rate have great influence on the microstructure features. {yields} The formation of sub-grain and dislocation wall is the typically microstructure features observed in the {beta} single-phase. {yields} The elongated lamellar {alpha} platelets kinked increasingly and break up under the {alpha} + {beta} processing conditions. {yields} The softening mechanisms of the Ti600 alloy hot compressed at 1000-1100 deg. C are mainly dynamic recovery. - Abstract: The influences of thermomechanical processing on microstructural evolution of Ti600 alloy were studied in the temperature range of 800-1100 deg. C, and at the strain rate of 0.001-10 s{sup -1}. During the isothermal compression experiment, the flow stress-strain curves are examined in the {beta} single-phase and in the {alpha} + {beta} two-phase regions. The results show that the thermomechanical processing parameters have significant influences on the microstructure of Ti600 alloy, especially on the grain size, morphologies of {alpha} phase. Moreover, the microstructural evolution was analyzed by optical microstructure (OM) and transmission electron microscopy (TEM). It was found that typical of dynamic recovery and dynamic recrystallization phenomenon occurring in the thermomechanical processing. These results will optimize the microstructural control for hot working of Ti600 alloy and deepen the understanding of the flow softening mechanism of near-{alpha} titanium alloy.

  13. Room temperature synthesis of Ni-based alloy nanoparticles by radiolysis.

    Energy Technology Data Exchange (ETDEWEB)

    Nenoff, Tina Maria; Berry, Donald T.; Lu, Ping; Leung, Kevin; Provencio, Paula Polyak; Stumpf, Roland Rudolph; Huang, Jian Yu; Zhang, Zhenyuan

    2009-09-01

    Room temperature radiolysis, density functional theory, and various nanoscale characterization methods were used to synthesize and fully describe Ni-based alloy nanoparticles (NPs) that were synthesized at room temperature. These complementary methods provide a strong basis in understanding and describing metastable phase regimes of alloy NPs whose reaction formation is determined by kinetic rather than thermodynamic reaction processes. Four series of NPs, (Ag-Ni, Pd-Ni, Co-Ni, and W-Ni) were analyzed and characterized by a variety of methods, including UV-vis, TEM/HRTEM, HAADF-STEM and EFTEM mapping. In the first focus of research, AgNi and PdNi were studied. Different ratios of Ag{sub x}- Ni{sub 1-x} alloy NPs and Pd{sub 0.5}- Ni{sub 0.5} alloy NP were prepared using a high dose rate from gamma irradiation. Images from high-angle annular dark-field (HAADF) show that the Ag-Ni NPs are not core-shell structure but are homogeneous alloys in composition. Energy filtered transmission electron microscopy (EFTEM) maps show the homogeneity of the metals in each alloy NP. Of particular interest are the normally immiscible Ag-Ni NPs. All evidence confirmed that homogeneous Ag-Ni and Pd-Ni alloy NPs presented here were successfully synthesized by high dose rate radiolytic methodology. A mechanism is provided to explain the homogeneous formation of the alloy NPs. Furthermore, studies of Pd-Ni NPs by in situ TEM (with heated stage) shows the ability to sinter these NPs at temperatures below 800 C. In the second set of work, CoNi and WNi superalloy NPs were attempted at 50/50 concentration ratios using high dose rates from gamma irradiation. Preliminary results on synthesis and characterization have been completed and are presented. As with the earlier alloy NPs, no evidence of core-shell NP formation occurs. Microscopy results seem to indicate alloying occurred with the CoNi alloys. However, there appears to be incomplete reduction of the Na{sub 2}WO{sub 4} to form the W

  14. Shape memory alloy thaw sensors

    Science.gov (United States)

    Shahinpoor, Mohsen; Martinez, David R.

    1998-01-01

    A sensor permanently indicates that it has been exposed to temperatures exceeding a critical temperature for a predetermined time period. An element of the sensor made from shape memory alloy changes shape when exposed, even temporarily, to temperatures above the Austenitic temperature of the shape memory alloy. The shape change of the SMA element causes the sensor to change between two readily distinguishable states.

  15. Plasticbell Circumcision for 800 Children with Phimosis%小儿包皮环切术套环法800例体会

    Institute of Scientific and Technical Information of China (English)

    王传学

    2014-01-01

    Objective To evaluate the experience of plastibell circumcision for the treatment of phimosis in children .Methods A ret-rospectively study was carried out for 800 cases with phimosis in children undergone plastibell circumcision in recent 10 years.Results The effect was satisfying in all of the patients.The shedding time of plastibell was 7 to 20 days.The surgical complications included hemor-rhage in four , inflammation of foreskin in eight , not shed of plastibell in five , laceration of foreskin in three , plastibell insetting into coro-nary sulcus in four , and urinary retention in two.Conclusion The plastibell circumcision was a good alterative for phimosis in children with short operation time, little bleeding amount, small trauma, less complications, less pain and convenient nursing.%目的:总结包皮环切术套环法治疗小儿包皮过长的经验。方法对2003~2013年来我院行包皮环切术套环法治疗小儿包皮过长的800例患儿行回顾性分析。结果800例行小儿包皮环切术套环法患儿术后效果良好。套环脱落时间为7~20d,脱落后切缘整齐,外形美观。26例出现不同程度的并发症。其中,术后出血4例;包皮感染、红肿8例;套环不脱落5例;包皮撕裂3例;包皮环嵌入冠状沟4例;尿潴留2例。结论小儿包皮环切术套环法具有手术时间短,手术出血少,创伤小,并发症少,患儿痛苦小,术后护理方便等优点,手术简单易于推广。

  16. Mo-Si alloy development

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.T.; Heatherly, L.; Wright, J.L. [Oak Ridge National Lab., TN (United States)

    1996-06-01

    The objective of this task is to develop new-generation corrosion-resistant Mo-Si intermetallic alloys as hot components in advanced fossil energy conversion and combustion systems. The initial effort is devoted to Mo{sub 5}-Si{sub 3}-base (MSB) alloys containing boron additions. Three MSB alloys based on Mo-10.5Si-1.1B (wt %), weighing 1500 g were prepared by hot pressing of elemental and alloy powders at temperatures to 1600{degrees}C in vacuum. Microporosities and glassy-phase (probably silicate phases) formations are identified as the major concerns for preparation of MSB alloys by powder metallurgy. Suggestions are made to alleviate the problems of material processing.

  17. Glass formation in eutectic alloys

    International Nuclear Information System (INIS)

    We have analyzed the glass forming ability around eutectic composition in terms of the competitive growth/formation of primary dendrites, eutectic and glass. It is concluded that the glass forming ability of a eutectic alloy system depends on the type of the eutectics, i.e. symmetric or asymmetric eutectic coupled zone. For the alloy systems with symmetric eutectic coupled zone, the best glass forming alloys should be at or very close to the eutectic composition. For the alloys with asymmetric eutectic coupled zone, which is associated with the irregular eutectic, the best glass forming alloys should be at off-eutectic compositions, probably towards the side of the faceted phase with a high entropy in the phase diagram. (orig.)

  18. The influence of thermomechanical treatment on structure of FeAl intermetallic phase-based alloys

    Directory of Open Access Journals (Sweden)

    I. Bednarczyk

    2008-08-01

    Full Text Available Purpose: The major problem restricting universal employment of intermetallic phase base alloy is their low plasticity which leads to hampering their development as construction materials. The following work concentrates on the analysis of microstructure and plasticity of ordered FeAl (B2 alloy during cold and hot deformation and rolling process.Design/methodology/approach: After casting and annealing, alloy specimens were subjected to axial-symmetric compression in the Gleeble 3800 simulator at temperatures ranging from 800, 900 and 1000°C at 0.1s-1 strain rate. In order to analyse the processes which take place during deformation, the specimens after deformation were intensely cooled with water. The process was conducted on the K -350 quarto rolling mill used for hot rolling of flat products. The process was conducted in some stages at temperature ranging from 1200-1000°C: Structural examination was carried out using light microscopy. The examination of the substructure was carried out by transmission electron microscopy (TEM.Findings: The research carried out enabled the understanding of the phenomena taking place during hot rolling of the investigated alloy. which has been also confirmed in plastometric studies conducted in the form of hot compression tests. The microstructure analyses applying optic and electron microscopy have revealed the structure reconstruction processes occurring in FeAl alloys during cold and hot deformation.Practical implications: The research carried out enabled the understanding of the phenomena taking place during deformation and annealing of the investigated alloy. The obtained sheets can be used as constructional elements working in complex stress fields, at a high temperature and corrosive environments. The results will constitute the basis for modelling the structural changes.Originality/value: The obtained results are vital for designing an effective thermo - mechanical processing technology for the

  19. Wedlable nickel aluminide alloy

    Energy Technology Data Exchange (ETDEWEB)

    Santella, Michael L. (Knoxville, TN); Sikka, Vinod K. (Oak Ridge, TN)

    2002-11-19

    A Ni.sub.3 Al alloy with improved weldability is described. It contains about 6-12 wt % Al, about 6-12 wt % Cr, about 0-3 wt % Mo, about 1.5-6 wt % Zr, about 0-0.02 wt % B and at least one of about 0-0.15 wt % C, about 0-0.20 wt % Si, about 0-0.01 wt % S and about 0-0.30 wt % Fe with the balance being Ni.

  20. Heating uranium alloy billets

    International Nuclear Information System (INIS)

    Data were obtained for the surface heat transfer coefficient of uranium and the alloys of uranium-0.75 wt percent titanium, uranium-6 wt percent niobium, and uranium-7.5 wt percent niobium-2.5 wt percent zirconium. Samples were heated to 8500C in both a molten salt bath and an argon-purged air furnace, then the samples were cooled in air. Surface heat transfer coefficients were calculated from the experimental data for both heating and cooling of the metals. 4 fig, 4 tables

  1. Cross Sections from 800 MeV Proton Irradiation of Terbium

    CERN Document Server

    Engle, J W; Bach, H; Couture, A; Jackman, K; Gritzo, R; Ballard, B D; Faßbender, M; Smith, D M; Bitteker, L J; Ullmann, J L; Gulley, M; Pillai, C; John, K D; Birnbaum, E R; Nortier, F M

    2012-01-01

    A single terbium foil was irradiated with 800 MeV protons to ascertain the potential for production of lanthanide isotopes of interest in medical, astrophysical, and basic science research and to contribute to nuclear data repositories. Isotopes produced in the foil were quantified by gamma spectroscopy. Cross sections for 36 isotopes produced in the irradiation are reported and compared with predictions by the MCNP6 transport code using the CEM03.03, Bertini, and INCL+ABLA event generators. Our results indicate the need to accurately consider fission and fragmentation of relatively light target nuclei like terbium in the modeling of nuclear reactions at 800 MeV. The predictive power of the code was found to be different for each event generator tested but was satisfactory for most of the product yields in the mass region where spallation reactions dominate. However, none of the event generators' results are in complete agreement with measured data.

  2. Cross sections from proton irradiation of thorium at 800 MeV

    CERN Document Server

    Engle, Jonathan W; Weidner, John W; Wolfsberg, Laura E; Fassbender, Michael E; Jackman, Kevin; Couture, Aaron; Bitteker, Leo J; Ullmann, John L; Gulley, Mark S; Pillai, Chandra; John, Kevin D; Birnbaum, Eva R; Nortier, Francois M

    2013-01-01

    Nuclear formation cross sections are reported for 65 nuclides produced from 800-MeV proton irradiation of thorium foils. These data are useful as benchmarks for computational predictions in the ongoing process of theoretical code development and also to the design of spallation-based radioisotope production currently being considered for multiple radiotherapeutic pharmaceutical agents. Measured data are compared with the predictions of three MCNP6 event generators and used to evaluate the potential for 800-MeV productions of radioisotopes of interest for medical radiotherapy. In only a few instances code predictions are discrepant from measured values by more than a factor of two, demonstrating satisfactory predictive power across a large mass range. Similarly, agreement between measurements presented here and those previously reported is good, lending credibility to predictions of target yields and radioimpurities for high-energy accelerator-produced radionuclides.

  3. Cross sections from 800 MeV proton irradiation of terbium

    Energy Technology Data Exchange (ETDEWEB)

    Engle, J.W., E-mail: jwengle@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mashnik, S.G.; Bach, H.; Couture, A.; Jackman, K.; Gritzo, R.; Ballard, B.D.; Fassbender, M.; Smith, D.M.; Bitteker, L.J.; Ullmann, J.L.; Gulley, M.S.; Pillai, C.; John, K.D.; Birnbaum, E.R. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Nortier, F.M., E-mail: meiring@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2012-11-02

    Terbium foils were irradiated with 800 MeV protons to ascertain the potential for production of lanthanide isotopes of interest in medical, astrophysical, and basic science research and to contribute to nuclear data repositories. Isotopes produced in the foil were quantified by gamma spectroscopy. Cross sections for 35 isotopes produced in the irradiation are reported and compared with predictions by the MCNP6 transport code using the CEM03.03, Bertini and INCL + ABLA event generators. Our results indicate the need to accurately consider fission and fragmentation of relatively light target nuclei like terbium in the modeling of nuclear reactions at 800 MeV. The predictive power of the code was found to be different for each event generator tested but was satisfactory for most of the product yields in the mass region where spallation reactions dominate. However, none of the event generators' results are in complete agreement with measured data.

  4. 800岁的英国珍档《大宪章》

    Institute of Scientific and Technical Information of China (English)

    胡劼

    2015-01-01

    今年,英国《大宪章》(拉丁文Magna Carta,英文Great Charter)迎来其800岁生日。从年初开始,一系列庆典活动相继在英国推出,以纪念这份标志着英国开始走向宪政的法律文件的诞生。国王与贵族的博弈—《大宪章》的诞生历程800年前的英国王室较之今日截然不同,当时的王权几乎完全凌驾于法律之上。伦敦大学国王学院中世纪历史教授大卫·卡彭特(David Carpenter)说:

  5. Scopus数据库将新增800多种期刊

    Institute of Scientific and Technical Information of China (English)

    厉衍飞

    2007-01-01

    作为世界上最大的文摘与引文数据库,Scopus(www.scopus.com)宣布在其原有15000种同行评审期刊的基础上再收录800种期刊,其中200份来自社会科学领域,这进一步强化了Scopus作为最全面的社会科学文摘库的地位。其他新增的期刊来自全球各地,涉及多个学科领域,包括生物医学和工程学等。新增的800多种期刊均是由用户推荐,并经过Scopus内容甄选委员会(CSAB)严格审核的。

  6. In situ Raman study of C60 polymerization during isothermal pressurizing at 800 K

    International Nuclear Information System (INIS)

    The first in situ Raman study of C60 isothermal compression at 800 K and up to 32 GPa was performed using rhombohedral and tetragonal phases as starting materials. The rhombohedral phase shows a phase transition to 3D polymer above 10 GPa, similar to that in experiments where isobaric heating was used at pressures of 9-13 GPa. It is shown that the T-P diagram of C60 polymeric phases (temperature increase followed by pressurizing) is significantly different from the known P-T diagram (pressurizing followed by heating). Tetragonal polymer exhibited significantly stronger stability and can be followed at least up to ∼15 GPa. Heating up to 800 K of tetragonal polymer at pressures of 6-8 GPa confirms that, due to geometrical frustrations, the tetragonal phase remains stable even at pressure and temperature conditions at which rhombohedral polymer is usually formed

  7. Effects of grain boundary sliding on the flow properties of Incoloy 800H

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, H.; Korhonen, M.A.; Li Cheyu (Dept. of Materials Science and Enginering, Cornell Univ., Ithaca, NY (United States))

    1992-08-01

    The nature of grain boundary sliding (GBS) is investigated in Incoloy 800H in terms of the effects of stress, temperature and grain size on the flow behavior observed by using the load relaxation test. Flow behaviors are obtained for average grain sizes ranging from 6 to 225 {mu}m at temperatures between 614 and 746degC. The flow behavior of large-grain-size material plotted as stress vs. strain rate in a doubly logarithmic scale, exhibits a sigmoidal shape which has been commonly associated with the effects of GBS on creep deformation. For the materials of smaller grain sizes the deformation properties tend toward those characteristic of structural superplasticity. It is shown that in Incoloy 800H there may exist, as a function of the grain size, a continuous scale of flow properties ranging from the normal creep to superplastic-like behavior. (orig.).

  8. Research on microstructural evolution and dynamic recrystallization behavior of JB800 bainitic steel by FEM

    Institute of Scientific and Technical Information of China (English)

    Qingjun Chen; Yonglin Kang; Hao Yu; Chunmei Wang; Chengxiang Li

    2008-01-01

    Single pass compression tests were conducted on Gleeble1500 thermal simulator. The effect of different deformation parameters on the grain size of dynamically recrystallized austenite was analyzed. A mathematical model of dynamic recrystallization and a material database of JB800 steel, whose tensile strength is above 800 Mpa, were set up. A subprogram was compiled using Fortran language and called by Marc finite element software. A thermal coupled elastoplastic finite element model was established to simulate the compression process. The grain size of recrystallized austenite obtained by different recrystailization models was simulated. The results show that the optimized dynamic recrystallization model of JBS00 bainitic steel has a higher precision and yields good agreement with metallographic observations.

  9. Nanocrystalline Hydroxyapatite/Si Coating by Mechanical Alloying Technique

    Science.gov (United States)

    Hannora, Ahmed E.; Mukasyan, Alexander S.; Mansurov, Zulkhair A.

    2012-01-01

    A novel approach for depositing hydroxyapatite (HA) films on titanium substrates by using mechanical alloying (MA) technique has been developed. However, it was shown that one-hour heat treatment at 800°C of such mechanically coated HA layer leads to partial transformation of desired HA phase to beta-tri-calcium phosphate (β-TCP) phase. It appears that the grain boundary and interface defects formed during MA promote this transformation. It was discovered that doping HA by silicon results in hindering this phase transformation process. The Si-doped HA does not show phase transition to β-TCP or decomposition after heat treatment even at 900°C. PMID:22312324

  10. Stable palladium alloys for diffusion of hydrogen

    Science.gov (United States)

    Patapoff, M.

    1973-01-01

    Literature search on hydrogen absorption effect on palladium alloys revealed existence of alloy compositions in which alpha--beta transition does not take place. Survey conclusions: 40 percent gold alloy of palladium should be used in place of palladium; alloy must be free of interstitial impurities; and metallic surfaces of tube must be clean.

  11. Corrosion of aluminum alloys as a function of alloy composition

    International Nuclear Information System (INIS)

    A study was initiated which included nineteen aluminum alloys. Tests were conducted in high purity water at 3600C and flow tests (approx. 20 ft/sec) in reactor process water at 1300C (TF-18 loop tests). High-silicon alloys and AlSi failed completely in the 3600C tests. However, coupling of AlSi to 8001 aluminum suppressed the failure. The alloy compositions containing iron and nickel survived tht 3600C autoclave exposures. Corrosion rates varied widely as a function of alloy composition, but in directions which were predictable from previous high-temperature autoclave experience. In the TF-18 loop flow tests, corrosion penetrations were similar on all of the alloys and on high-purity aluminum after 105 days. However, certain alloys established relatively low linear corrosion rates: Al-0.9 Ni-0.5 Fe-0.1 Zr, Al-1.0 Ni-0.15 Fe-11.5 Si-0.8 Mg, Al-1.2 Ni-1.8 Fe, and Al-7.0 Ni-4.8 Fe. Electrical polarity measurements between AlSi and 8001 alloys in reactor process water at temperatures up to 1500C indicated that AlSi was anodic to 8001 in the static autoclave system above approx. 500C

  12. 加捻对T800碳纤维拉伸性能的影响%The Effect of Twisting on the Tensile Properties of T800 Carbon Fibre

    Institute of Scientific and Technical Information of China (English)

    关洪涛; 李辅安; 程勇

    2011-01-01

    要通过对日本东丽1700、T800碳纤维复丝拉伸性能的表征主要研究了加捻对,T800碳纤维拉伸性能的影响。研究结果表明:采用浸胶后加捻的方式有助于改善T800碳纤维的拉伸性能,合适的捻度可使其拉伸强度提高5%,断裂延伸率提高10%。并通过对rr800碳纤维干纱加捻的研究基本确定了T800碳纤维的临界捻度为15n/m。%By means of testing on the tensile properties of T700 and T800 carbon fibre made in Japanese Toray Company, the effect of twisting on the tensile properties of T800 carbon fibre is researched in this paper. The results show that the method of twisting after dipping is conductive to improve the tensile properties of T800 carbon fibre. The tensile strength can be improved by 5% and the elongation at break can be improved by 10% when the twist is 15 n/re. In additon, the critical twist of T800 carbon fibre can be determined as 15 n/m by the research on the twisting of T800 carbon fibre without dipping.

  13. Comparison of temperature standards. 800 deg C to 1500 deg C (radiation pyrometers). Pt. 2

    International Nuclear Information System (INIS)

    A comparison between implementations of the temperature scale (IPTS-68) between 800 deg C to 1500 deg C was made at the Department of Physics and Metrology at INTI, using pyrometric lamps with a tungsten filament which were calibrated at the Physikalisch-Technische Bundesanstalt (PTB). The purpose of this analysis was the detection of possible systematic errors as well as the evaluation of the uncertainty limit. (Author)

  14. 800-MW Supercritical Coal-Fired Boilers in Suizhong Power Plant

    Institute of Scientific and Technical Information of China (English)

    Zou Haifeng; Li Zhishan; Liu Zhongqi; Yan Hongyong; Zhang Yuanliang; Wang Lei

    2005-01-01

    This article reviews the problems of Russia-made 800-MW coal-fired supercritical boilers inSuizhong Power Plant, such as burner burnout, water-wall leakage, slag screen I explosion, crack happenedon the desuperheater outlet of reheater and welding defect of economizer; tells the process of renovating theseunits by modifying the original design and adjusting the operation parameters. After several years' effort, allthe problems have been well solved. The experience may be useful for other imported units in China.

  15. Design & simulation of a 800 kV dynamitron accelerator by CST studio

    Directory of Open Access Journals (Sweden)

    A M Aghayan

    2015-09-01

    Full Text Available Nowadays, middle energy electrostatic accelerators in industries are widely used due to their high efficiency and low cost compared with other types of accelerators. In this paper, the importance and applications of electrostatic accelerators with 800 keV energy are studied. Design and simulation of capacitive coupling of a dynamitron accelerator is proposed. Furthermore, accelerating tube are designed and simulated by means of CST Suit Studio

  16. A synthesis of the Antarctic surface mass balance during the last 800 yr

    OpenAIRE

    Frezzotti, M.; C. Scarchilli; Becagli, S.; Proposito, M.; S. Urbini

    2013-01-01

    Global climate models suggest that Antarctic snowfall should increase in a warming climate and mitigate rises in the sea level. Several processes affect surface mass balance (SMB), introducing large uncertainties in past, present and future ice sheet mass balance. To provide an extended perspective on the past SMB of Antarctica, we used 67 firn/ice core records to reconstruct the temporal variability in the SMB over the past 800 yr and, in greater detail, over the last 200 yr.

  17. Identity construction and maintenance in the North Atlantic c. AD800-1250

    OpenAIRE

    Knight, Dayanna

    2014-01-01

    This study is a multivalent investigation of Scandinavian identity formation and cultural structures within the north Atlantic that looks specifically at the construction and maintenance of island identities circa AD800-1250. This not only includes consideration of the Norse settlers but also the effects of contact between the emerging island cultural identities and continental Europe. In order to do this zones of settlement have been defined to better compare the expansion of medieval Scand...

  18. Exotic baryon searches in 800 GeV/c pp {yields} pX

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, M.A.; Felix, J.; Lopez, E.; Moreno, G.; Perez, I.O.; Sosa, M. [Universidad de Guanajuato, Leon, Guanajuato (Mexico); Christian, D.C.; Gottschalk, E.E.; Gutierrez, G.; Wang, M.H.L.S.; Wehmann, A. [Fermi National Accelerator Laboratory, Batavia, IL (United States); Hartouni, E.P. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Knapp, B.C. [Columbia University, Irvington, NY (United States). Nevis Lab.; Kreisler, M.N. [University of Massachusetts, Amherst, MA (United States)

    2005-07-01

    We report the results of the search for the pentaquark candidates {theta}(1540) and {xi}(1862) using data from Fermilab experiment E690 in the reaction pp {yields} pX at 800 GeV/c. We find no evidence for narrow baryon resonances near 1862 MeV decaying to {xi}{pi}. Also, we find no evidence of a narrow resonance near 1540 MeV decaying to pK{sub s}{sup 0}. (author)

  19. Self-seeded lasing in ionized air pumped by 800 nm femtosecond laser pulses

    OpenAIRE

    Liu, Yi; Brelet, Yohann; Point, Guillaume; Houard, Aurélien; Mysyrowicz, André

    2013-01-01

    We report on the lasing in air and pure nitrogen gas pumped by a single 800 nm femtosecond laser pulse. Depending on gas pressure, incident laser power and beam convergence, different lasing lines are observed in the forward direction with rapid change of their relative intensities. The lines are attributed to transitions between vibrational and rotational levels of the first negative band of the singly charged nitrogen molecule-ion. We show that self-seeding plays an important role in the ob...

  20. Merevägi soetab 800 miljoni eest uusi laevu / Peeter Kuimet

    Index Scriptorium Estoniae

    Kuimet, Peeter

    2005-01-01

    Kaitseministeerium ootab valitsuselt heakskiitu 800 miljoni krooni eraldamiseks Eesti mereväele kahe uue miinijahtija ostmiseks, mis vahetaksid välja ligi 40 aastat vanad miinitraalerid Vaindlo ja Olevi. Olenevalt hankeprotsessist ja meeskondade väljaõppest peaksid uued alused olema rivis umbes 2008. aastaks. Lisaks laevadele uuendab kaitsevägi lähiaastail ka maavägede relvastust. Lisa: Miiniotsijad

  1. An 800-year paleoflood record from the Sacramento Valley, California [abstract

    OpenAIRE

    Byrne, Roger; Sullivan, Donald

    1996-01-01

    EXTRACT (SEE PDF FOR FULL ABSTRACT): Four cores recovered from Little Packer Lake in Glenn County, California, have provided a paleoflood record for the past 800 years. ... The sequence of flood deposits in the top 2 meters of the record shows a reasonable agreement with the known history of floods during the past 150 years. At least three major flood events are indicated for AD 1400-1525, although these dates may have to be revised when more dates become available.

  2. J/ψ and ψ' production with 800 GeV protons

    International Nuclear Information System (INIS)

    The yields of J/ψ and ψ' vector meson states have been measured for 800 GeV protons incident on deuterium, carbon, calcium, iron and tungsten targets. A depletion of the yield per nucleon from heavy nuclei is observed for both J/ψ and ψ' production. This depletion exhibits a strong dependence on xF and pt. 24 refs., 3 figs

  3. 7 CFR 800.72 - Explanation of additional service fees for services performed in the United States only.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Explanation of additional service fees for services performed in the United States only. 800.72 Section 800.72 Agriculture Regulations of the Department of... fees for services performed in the United States only. (a) When transportation of the...

  4. 36 CFR Appendix A to Part 800 - Criteria for Council Involvement in Reviewing Individual section 106 Cases

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Criteria for Council Involvement in Reviewing Individual section 106 Cases A Appendix A to Part 800 Parks, Forests, and Public... Appendix A to Part 800—Criteria for Council Involvement in Reviewing Individual section 106 Cases...

  5. High-temperature gas-cooled reactor helium compatibility studies: results of 10,000-hour exposure of selected alloys in simulated reactor helium

    Energy Technology Data Exchange (ETDEWEB)

    Lechtenberg, T.A.; Stevenson, R.D.; Johnson, W.R.

    1980-05-01

    Work on the HTGR Helium Compatibility Task accomplished during the period March 31, 1977 through September 30, 1979, is documented in this report. Emphasis is on the results and analyses of creep data to 10,000 h and the detailed metallurgical evaluations performed on candidate alloy specimens tested for up to 10,000 h. Long-term creep and unstressed aging data in controlled-impurity helium and in air at 800, 900, and 1000/sup 0/C are reported for alloys included in the program in FY-76, including the wrought solid-solution-strengthened alloys, Hastelloy X, Hastelloy S, RA 333, and HD 556, and the centrifugally cast austenitic alloys, HK 40, Supertherm, Manaurite 36X, Manaurite 36XS, and Manaurite 900.

  6. High-temperature gas-cooled reactor helium compatibility studies: results of 10,000-hour exposure of selected alloys in simulated reactor helium

    International Nuclear Information System (INIS)

    Work on the HTGR Helium Compatibility Task accomplished during the period March 31, 1977 through September 30, 1979, is documented in this report. Emphasis is on the results and analyses of creep data to 10,000 h and the detailed metallurgical evaluations performed on candidate alloy specimens tested for up to 10,000 h. Long-term creep and unstressed aging data in controlled-impurity helium and in air at 800, 900, and 10000C are reported for alloys included in the program in FY-76, including the wrought solid-solution-strengthened alloys, Hastelloy X, Hastelloy S, RA 333, and HD 556, and the centrifugally cast austenitic alloys, HK 40, Supertherm, Manaurite 36X, Manaurite 36XS, and Manaurite 900

  7. Microstructure Refinement of Sn-Sb Peritectic Alloy under High-Intensity Ultrasound Treatment%功率超声细化Sn-Sb包晶合金

    Institute of Scientific and Technical Information of China (English)

    QI Fei-peng; ZHANG Hai-bo; GAO Shou-lei; ZHAI Qi-jie

    2005-01-01

    In this paper the solidification behavior of Sn-Sb peritectic alloy and the mechanism of grain refinement in solidification process under high-intensity ultrasonic field are investigated. Three different powers of high-intensity ultrasound are introduced into molten Sn-Sb peritectic alloy to study the refining effectiveness. The results show that the application of high-intensity ultrasound during solidification process of Sn-Sb peritectic alloy can refine α phase and β phase and eliminate gravity segregation of the alloy. As acoustic intensity is increased from 400 W to 800 W, not only the homogenous fine structure can be obtained, but also the cubic β phase crystals tend to be spherical. Microstructure of the sample treated by 600 W high-intensity ultrasound demonstrates the best refining effect.

  8. Overvoltage and Insulation Coordination for Valve Winding of ±800 kV UHVDC Converter Transformer

    Institute of Scientific and Technical Information of China (English)

    ZHOU Peihong; DAI Ming; HE Huiwen

    2012-01-01

    The determination of insulation levels for valve windings of ± 800 kV UHVDC converter transformers is a key problem for designing and manufacturing of the converter transformers. Based on the Yunnan-Guangdong ± 800 kV DC power transmission project, the arrester parameters for direct or indirect protection of the valve windings are selected. The EMTDC program is used to calculate several faults, which determine mainly the specified insulation levels of valve winding for temporary, switching and lightning impulses, and the overvoltage generating mechanisms according to these faults are analyzed. The polarity reversal overvohage and the related reversal time at valve windings caused by the emergency switch off sequence of converters (ESOF) are calculated to confirm the necessity of DC voltage polarity reversal type tests of valve windings. The reasonability of the three insulation coordination methods, which determine converter transformers' switching impulse insulation levels, is analyzed. Method 1 is concluded to be more reasonable, and it is used to determine the switching impulse withstand voltage (SIWV) from the switching overvohage calculation results. The lightning impulse withstand voltage (LIWV) of valve windings can be determined by the ratio between LIWV and SIWV. The principle of the ratio selection is presented, and it is used to determine the LIWV. The operation experience of Yunnan-Guangdong ±800 kV DC project has proven that the presented insulation levels is appropriate.

  9. Low temperature ageing of silicas Gasil-I and TK800

    International Nuclear Information System (INIS)

    Gasil-I (a mesoporous silica) and TK800 (a non-porous pyrogenic silica) were investigated in the early 1970s as standard reference materials. Since then the specific surface areas of both silicas have decreased to ∼85% of their initial values, suggesting that the surface character and the ageing mechanism may be the same for both. Comparisons of the shapes of nitrogen-adsorption isotherms, confirmed by comparisons of the shape ratios for Gasil-I and TK800, indicate that Gasil-I has greater microbore character and a higher absorption at p/p0 > 0.5 than TK800 and that the isotherm shapes have changed little since 1974. The specific volume of Gasil-I has remained nearly constant during the ageing period but the pore size distribution (PSD) has shifted markedly to higher values. Electron micrographs show that low (room) temperature gas-solid ageing results in similar enlargement at the point of contact between attached secondary particles as that which occurs in hydrothermal ageing. In the gas-solid case, this change, which accounts for the decrease in overall surface area, is attributed to the surface transport of silica material in the presence of near monolayer quantities of adsorbed water. Ageing in this manner is geometry-limited so that the rate of ageing is expected to approach zero, resulting in time-stable silicas

  10. Microstructural characterization of dissimilar welds between Incoloy 800H and 321 Austenitic Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    Sayiram, G., E-mail: sayiram.g@vit.ac.in; Arivazhagan, N.

    2015-04-15

    In this work, the microstructural character of dissimilar welds between Incoloy 800H and 321 Stainless Steel has been discussed. The microscopic examination of the base metals, fusion zones and interfaces was characterized using an optical microscope and scanning electron microscopy. The results revealed precipitates of Ti (C, N) in the austenitic matrix along the grain boundaries of the base metals. Migration of grain boundaries in the Inconel 82 weld metal was very extensive when compared to Inconel 617 weldment. Epitaxial growth was observed in the 617 weldment which increases the strength and ductility of the weld metal. Unmixed zone near the fusion line between 321 Stainless Steel and Inconel 82 weld metal was identified. From the results, it has been concluded that Inconel 617 filler metal is a preferable choice for the joint between Incoloy 800H and 321 Stainless Steel. - Highlights: • Failure mechanisms produced by dissimilar welding of Incoloy 800H to AISI 321SS • Influence of filler wire on microstructure properties • Contemplative comparisons of metallurgical aspects of these weldments • Microstructure and chemical studies including metallography, SEM–EDS • EDS-line scan study at interface.

  11. Specification of Main Stations for ±800 Equipment in Converter kV UHVDC Projects

    Institute of Scientific and Technical Information of China (English)

    YANG Yiming; ZHANG Lei

    2012-01-01

    Up to now, ±800 kV ultra high voltage direct current(UHVDC) systems have the highest voltage level among existing DC systems in the world, thus the specification of the main equipments in the system's converter stations should be set carefully. Taking the system design and consultation of the Jinping-Sunan ± 800 kV UHVDC transmission project as an example, its specification of main equipments and key system technical parameters are presented and studied. The method of selecting parameters of station main equipment and the simulation result of system study are presented, in order to make a general description of ±800 kV UHVDC co system studies, such as system single line diagram (SLD) insulation margin, overload capability, transformer parameter, valve short current stress, and DC breaker study. As a result of the studies above, the surge arrester configuration of UHVDC system, insulation margin, overload capability, electrical design of valve and transformer had been given out in this paper. These specifications gave support to the development of equipment and construction of the project, and generalize experiences for future UHVDC project designs.

  12. BN800: The advanced sodium cooled fast reactor plant based on close fuel cycle

    International Nuclear Information System (INIS)

    As one of the advanced countries with actually fastest reactor technology, Russia has always taken a leading role in the forefront of the development of fast reactor technology. After successful operation of BN600 fast reactor nuclear power station with a capacity of six hundred thousand kilowatts of electric power for nearly 30 years, and after a few decades of several design optimization improved and completed on its basis, it is finally decided to build Unit 4 of Beloyarsk nuclear power station (BN800 fast reactor power station). The BN800 fast reactor nuclear power station is considered to be the project of the world's most advanced fast reactor nuclear power being put into implementation. The fast reactor technology in China has been developed for decades. With the Chinese pilot fast reactor to be put into operation soon, the Chinese model fast reactor power station has been put on the agenda. Meanwhile, the closed fuel cycle development strategy with fast reactor as key aspect has given rise to the concern of experts and decision-making level in relevant areas. Based on the experiences accumulated in many years in dealing the Sino-Russian cooperation in fast reactor technology, with reference to the latest Russian published and authoritative literatures regarding BN800 fast reactor nuclear power station, the author compiled this article into a comprehensive introduction for reference by leaders and experts dealing in the related fields of nuclear fuel cycle strategy and fast reactor technology development researches, etc. (authors)

  13. A study of the resonances $K_{0}^{*}(800)$ and $K_{0}^{*}(1430)$

    CERN Document Server

    Soltysiak, Milena; Giacosa, Francesco

    2016-01-01

    We study the scalar kaonic states $K_{0}^{\\ast}(800)$ and $K_{0}^{\\ast}(1430)$ by using a relativistic QFT Lagrangian in which only a single kaonic field corresponding to the well-established scalar state $K_{0}^{\\ast}(1430)$ is considered and in which both derivative and non-derivative interaction terms are taken into account. Even if the scalar spectral function shows a unique peak close to $1.4$ GeV, we find two poles in the complex plane: $1.413\\pm0.002-i(0.127\\pm0.003)$ GeV, which is related to the seed quark-antiquark state $K_{0}^{\\ast}(1430),$ and $0.746\\pm0.019-i(262\\pm0.014)$ GeV, which is an additional companion pole related to $K_{0}^{\\ast}(800)$. As a further investigation for increasing $N_{c}$ confirms, $K_{0}^{\\ast}(800)$ emerges as a dynamically generated four-quark object as a consequence of pion-kaon loops.

  14. On the origin of multidecadal to centennial Greenland temperature anomalies over the past 800 yr

    Directory of Open Access Journals (Sweden)

    T. Kobashi

    2013-03-01

    Full Text Available The surface temperature of the Greenland ice sheet is among the most important climate variables for assessing how climate change may impact human societies due to its association with sea level rise. However, the causes of multidecadal-to-centennial temperature changes in Greenland temperatures are not well understood, largely owing to short observational records. To examine these, we calculated the Greenland temperature anomalies (GTA[G-NH] over the past 800 yr by subtracting the standardized northern hemispheric (NH temperature from the standardized Greenland temperature. This decomposes the Greenland temperature variation into background climate (NH; polar amplification; and regional variability (GTA[G-NH]. The central Greenland polar amplification factor as expressed by the variance ratio Greenland/NH is 2.6 over the past 161 yr, and 3.3–4.2 over the past 800 yr. The GTA[G-NH] explains 31–35% of the variation of Greenland temperature in the multidecadal-to-centennial time scale over the past 800 yr. We found that the GTA[G-NH] has been influenced by solar-induced changes in atmospheric circulation patterns such as those produced by the North Atlantic Oscillation/Arctic Oscillation (NAO/AO. Climate modeling and proxy temperature records indicate that the anomaly is also likely linked to solar-paced changes in the Atlantic meridional overturning circulation (AMOC and associated changes in northward oceanic heat transport.

  15. [Therapy of duodenal ulcer and pyloric ulcer with 800 mg cimetidine nightly].

    Science.gov (United States)

    Schütze, K; Hentschel, E; Weiss, W; Kratochvil, P; Brandstätter, G; Menthe, W; Okulski, G

    1986-04-18

    The efficacy of cimetidine 400 mg b.i.d. as compared with a single evening dose 800 mg was evaluated in a single-blind multicentre trial involving 86 patients with endoscopically proven duodenal or pyloric ulcer. After four weeks of treatment the healing rates were 64.4% (29/45) with 400 mg cimetidine twice daily and 78% (32/41) with 800 mg nocte; after eight weeks the corresponding rates were 77.7% (35/45) and 85.3% (35/41). Administration of 800 mg cimetidine every evening is, consequently, at least as effective as a twice-daily regimen. In the second half of the treatment period it was significantly more effective in reducing pain and antacid consumption. The single noctural dose takes the pathogenetic importance of overnight gastric acidity into consideration, entails a simplification of therapy and may improve patient compliance. It should, therefore, take preference over the conventional twice-daily regimen. PMID:3521103

  16. Binding of more than one Tva800 molecule is required for ASLV-A entry

    Directory of Open Access Journals (Sweden)

    Gray Eleanor R

    2011-11-01

    Full Text Available Abstract Background Understanding the mechanism by which viruses enter their target cell is an essential part of understanding their infectious cycle. Previous studies have focussed on the multiplicity of viral envelope proteins that need to bind to their cognate receptor to initiate entry. Avian sarcoma and leukosis virus Envelope protein (ASLV Env mediates entry via a receptor, Tva, which can be attached to the cell surface either by a phospholipid anchor (Tva800 or a transmembrane domain (Tva950. In these studies, we have now investigated the number of target receptors necessary for entry of ASLV Env-pseudotyped virions. Results Using titration and modelling experiments we provide evidence that binding of more than one receptor, probably two, is needed for entry of virions via Tva800. However, binding of just one Tva950 receptor is sufficient for successful entry. Conclusions The different modes of attachment of Tva800 and Tva950 to the cell membrane have important implications for the utilisation of these proteins as receptors for viral binding and/or uptake.

  17. On the Origin of Multidecadal to Centennial Greenland Temperature Anomalies Over the Past 800 yr

    Science.gov (United States)

    Kobashi, T.; Shindell, D. T.; Kodera, K.; Box, J. E.; Nakaegawa, T.; Kawamura, K.

    2013-01-01

    The surface temperature of the Greenland ice sheet is among the most important climate variables for assessing how climate change may impact human societies due to its association with sea level rise. However, the causes of multidecadal-to-centennial temperature changes in Greenland temperatures are not well understood, largely owing to short observational records. To examine these, we calculated the Greenland temperature anomalies (GTA[G-NH]) over the past 800 yr by subtracting the standardized northern hemispheric (NH) temperature from the standardized Greenland temperature. This decomposes the Greenland temperature variation into background climate (NH); polar amplification; and regional variability (GTA[G-NH]). The central Greenland polar amplification factor as expressed by the variance ratio Greenland/NH is 2.6 over the past 161 yr, and 3.3-4.2 over the past 800 yr. The GTA[G-NH] explains 31-35%of the variation of Greenland temperature in the multidecadal-to-centennial time scale over the past 800 yr. We found that the GTA[G-NH] has been influenced by solar-induced changes in atmospheric circulation patterns such as those produced by the North Atlantic Oscillation/Arctic Oscillation (NAO/AO). Climate modeling and proxy temperature records indicate that the anomaly is also likely linked to solar-paced changes in the Atlantic meridional overturning circulation (AMOC) and associated changes in northward oceanic heat transport.

  18. Galvanic cells including cobalt-chromium alloys.

    Science.gov (United States)

    Gjerdet, N R

    1980-01-01

    Galvanic cells may be created when dentures made of cobalt-chromium alloys are placed on teeth with metallic restorations. The power of such cells was evaluated in an in vitro galvanic using amalgams, gold alloy, and nickel-chromium alloys. The amalgams and one of the nickel-chromium alloys revealed high corrosion currents when placed in contact with cobalt-chromium alloy, the conventional amalgam showing the highest values. The gold alloy and another nickel-chromium alloy exhibited low corrosion currents and they were noble with respect to cobalt-chromium.

  19. Effects of PbO on the oxide films of incoloy 800HT in simulated primary circuit of PWR

    Science.gov (United States)

    Tan, Yu; Yang, Junhan; Wang, Wanwan; Shi, Rongxue; Liang, Kexin; Zhang, Shenghan

    2016-05-01

    Effects of trace PbO on oxide films of Incoloy 800HT were investigated in simulated primary circuit water chemistry of PWR, also with proper Co addition. The trace PbO addition in high temperature water blocked the protective spinel oxides formation of the oxide films of Incoloy 800HT. XPS results indicated that the lead, added as PbO into the high temperature water, shows not only +2 valance but also +4 and 0 valances in the oxide film of 800HT co-operated with Fe, Cr and Ni to form oxides films. Potentiodynamic polarization results indicated that as PbO concentration increased, the current densities of the less protective oxide films of Incoloy 800HT decreased in a buffer solution tested at room temperature. The capacitance results indicated that the donor densities of oxidation film of Incoloy 800HT decreased as trace PbO addition into the high temperature water.

  20. [Prosthetic dental alloys. 1].

    Science.gov (United States)

    Quintero Engelmbright, M A

    1990-11-01

    A wide variety of restoration materials for prosthetic odontology is now available to the dental surgeon, either of the covalent type (acrylic resins), metallic (alloys), ionic (porcelains), or a combination of them, as in the so-called composites, such as the composite resins, or as ceramics-metals mixtures. An example of the latter is a product called Miracle-Mix, a glass ionomere cement reinforced with an amalgam alloy. In those cases where the blend is done by a synterization process, the material is called Cermet. The above-listed alternatives clearly evidence day-to-day advances in odontology, with researchers and manufacturers engaged the world over in improving existing products or developing new ones to enrich the dentist's armamentarium. As a side effect of this constant renewal, those dentists who have failed to update their knowledge fall behind in their practice as they persist in using products they have known for years, and may be deceived by advertisements of too-often unreliable products. It is, therefore, important to be aware of available products and their latest improvements. PMID:2132464

  1. [Prosthetic dental alloys (2)].

    Science.gov (United States)

    Quintero Englembright, M A

    1990-12-01

    A wide variety of restoration materials for prosthetic odontology is now available to the dental surgeon, either of the covalent type (acrylic resins), metallic (alloys), ionic (porcelains), or a combination of them, as in the so-called composites, such as the composite resins, or as ceramics-metals mixtures. An example of the latter is a product called Miracle-Mix, a glass ionomere cement reinforced with an amalgam alloy. In those cases where the blend is done by a synterization process, the material is called Cermet. The above-listed alternatives clearly evidence day-to-day advances in odontology, with researchers and manufacturers engaged the world over in improving existing products or developing new ones to enrich the dentist's armamentarium. As a side effect of this constant renewal, those dentists who have failed to update their knowledge fall behind in their practice as they persist in using products they have known for years, and may be deceived by advertisements of too-often unreliable products. It is, therefore, important to be aware of available products and their latest improvements. PMID:2132470

  2. Microstructure and mechanical properties of V–4Ti–4Cr alloy as a function of the chemical heat treatment regimes

    International Nuclear Information System (INIS)

    The regularities of the formation of a heterophase structure and mechanical properties of V–4Ti–4Cr alloy as a function of thermomechanical and chemical heat treatments are studied. The regimes of thermomechanical treatment which provide the formation of a heterophase structure with a homogeneous volume distribution of oxycarbonitride nanoparticles with a size of about 10 nm and an increase in the volume content and thermal stability of this phase and which provide an increase in the temperature of alloy recrystallization are developed. The formation of the heterophase structure results in a substantial (up to 70%) increase in the short-term high-temperature strength of the alloy at T = 800°C. The increase in the strength is achieved while keeping a rather high level of plasticity

  3. Effect of hydrogen on the ductility and deformation resistance of VT6 titanium alloy at temperatures up to 930 C

    Energy Technology Data Exchange (ETDEWEB)

    Bashkin, I.O.; Malyshev, V.IU.; Aksenov, IU.A.; Antonova, T.E.; Poniatovskii, E.G. (Institut Fiziki Tverdogo Tela, Moscow (USSR) Institut Mashinovedeniia and Institut Fiziki Metallov, Sverdlovsk (USSR))

    1990-05-01

    Specimens of VT6 titanium alloy with a hydrogen content of 0-1.12 percent by weight were tested under tensile and compressive loading at temperatures up to 930 C. In the temperature range 300-800 C, the dependence of the strength properties of the alloy on the hydrogen content is characterized by a minimum at x = 0.3-0.4 wt pct and is nonmonotonic at x equal to or greater than 0.6 wt pct. The hydrogen concentrations corresponding to the strength minimum also correspond to maximum ductility. At 930 C, the 0.2-pct yield stress and the ultimate tensile strength vs hydrogen content increase monotonically with hydrogen content in the alloy. 8 refs.

  4. Investigation of the Wear and Hardness Behaviour of Aluminium Alloy Coated Using the Powder Flame Spraying Method

    Directory of Open Access Journals (Sweden)

    Nurullah KIRATLI

    2009-03-01

    Full Text Available In this study, the wear behavior of aluminum alloy AL 5754 ( Etial 53 coated with powders of 10Al-Cu alloy (RotoTec® 19850 and 15Cr7Fe-Ni alloy (RotoTec® 19985 using powder flame spraying method has been investigated. To avoid thermal expansions between substrate and coating materials, Ni-Al RotoTec® 51000 was used as binding material. The wear test was performed on a pin-on-disc test apparatus. As an abrasive material, a SiC, 800 sandpaper was used. The wear tests of coated materials were carried out at room temperature and at 1.0m/s sliding speed with 0.35 and 0.70MPa pressures. To characterize coated specimens, they have been examined with optical microscope. As a result, it is found that the both coating materials have improved wear resistance.

  5. Microstructure and mechanical properties of V–4Ti–4Cr alloy as a function of the chemical heat treatment regimes

    Energy Technology Data Exchange (ETDEWEB)

    Potapenko, M. M., E-mail: mmp@bochvar.ru; Chernov, V. M.; Drobyshev, V. A.; Kravtsova, M. V.; Kudryavtseva, I. E.; Degtyarev, N. A. [Bochvar High-Technology Research Institute of Inorganic Materials (Russian Federation); Ovchinnikov, S. V.; Tyumentsev, A. N.; Ditenberg, I. A.; Pinzhin, Yu. P.; Korotaev, A. D. [Russian Academy of Sciences, Institute of Strength Physics and Materials Science, Siberian Branch (Russian Federation)

    2015-12-15

    The regularities of the formation of a heterophase structure and mechanical properties of V–4Ti–4Cr alloy as a function of thermomechanical and chemical heat treatments are studied. The regimes of thermomechanical treatment which provide the formation of a heterophase structure with a homogeneous volume distribution of oxycarbonitride nanoparticles with a size of about 10 nm and an increase in the volume content and thermal stability of this phase and which provide an increase in the temperature of alloy recrystallization are developed. The formation of the heterophase structure results in a substantial (up to 70%) increase in the short-term high-temperature strength of the alloy at T = 800°C. The increase in the strength is achieved while keeping a rather high level of plasticity.

  6. Density of Liquid Ni-Cr Alloy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The density of liquid Ni-Cr alloy was measured by a modified sessile drop method. The density of liquid Ni-Cr alloywas found to decrease with increasing temperature and Cr concentration in the alloy. The molar volume of liquidNi-Cr alloy increases with increasing the Cr concentration in the alloy. The molar volume of Ni-Cr alloy determinedin the present work shows a positive deviation from the linear molar volume.

  7. South Asian monsoon variability during the past 800 kyr revealed by rock magnetic proxies

    Science.gov (United States)

    Suganuma, Y.; Yamazaki, T.; Kanamatsu, T.

    2009-05-01

    A rock magnetic investigation was carried out on a sedimentary core taken from the distal portion of the Bengal Fan in order to reconstruct the South Asian monsoon variability during the past 800 kyr. The 10.2 m long piston core MR0503-PC3, recovered at a water depth of 4400 m, consists of clay to silty clay with minor amounts of nannofossils. An age model for the MR0503-PC3 core is established by correlating a relative paleointensity record of the core [Suganuma Y., Yamazaki, T., Kanamatsu, T., Hokanishi, N., 2008. Relative paleointensity record during the last 800 kyr from the equatorial Indian Ocean: implication for relationship between inclination and intensity variations. Geochemistry, Geophysics, Geosystems. 9, Q02011. doi:10.1029/2007GC001723.] to the global paleointensity stack "Sint-800" [Guyodo, Y., Valet, J.P., 1999. Global changes in intensity of the Earth's magnetic field during the past 800 kyr. Nature. 399, 249-252.]. The age model is consistent with the published ages of tephra layers intercalated in the core, and shows continuous sedimentation during the past 800 kyr. Temporal variations in rock magnetic proxies for the magnetic concentration (ARM, IRM, and HIRM), the grain size (Mrs/Ms), and the composition (S -0.3T and S -0.1T) show that the amount of fine-grained magnetite increased during interglacial stages, and then gradually decreased toward the following glacial maxima. This indicates that the supply of fine-grained magnetite probably originated from areal expansion and/or increased pedogenic activity in the Ganges and Brahmaputra Rivers catchment. Increases during warmer periods suggest intensification of the South Asian summer monsoon during interglacial stages. During marine isotope stages (MIS) 15-11, enhancement of fine-grained magnetite and increased hematite and maghemite contributions are observed. These suggest a significant intensification of the South Asian summer monsoon during this period. Our record and other paleoclimatic

  8. The Effect of the Heat Treatment Regime on the Structure and Physical-Mechanical Properties of a 23X15KT Hard Magnetic Alloy

    Science.gov (United States)

    Korznikov, A. V.; Dmitriev, S. V.; Korznikova, G. F.; Gladkovskii, S. V.; Potekaev, A. I.

    2015-02-01

    The structure and magnetic and mechanical behavior of a hard magnetic alloy (Fe - 23% Cr - 15% Co - 1% Ti - 0.5% V) is investigated following a high-temperature hardening, an additional annealing within the temperature interval 800-1200°C, and a subsequent stepwise tempering to achieve a highly coercive state. It is found out that a decrease in the annealing temperature to 1000°C; and a transition into a two-phase state result in a sharp increase in hardness and coercive force. A further decrease in the hardening temperature down to 800° gives rise to lower hardness and deteriorated magnetic properties.

  9. Mechanically Alloyed High Entropy Composite

    Science.gov (United States)

    Popescu, G.; Adrian, M. M.; Csaki, I.; Popescu, C. A.; Mitrică, D.; Vasile, S.; Carcea, I.

    2016-08-01

    In the last years high entropy alloys have been investigated due to their high hardness, high temperature stability and unusual properties that make these alloys to have significant interest. In comparison with traditional alloys that are based on two or three major elements, this new generation alloys consists at least of 5 principal elements, with the concentration between 5 and 35 at.%. The present paper reports synthesis of high entropy alloys (HEA) and high entropy composites (HEC) synthesized by mechanical alloying (MA). The equiatomic AlCrFeNiMn matrix was used for creating the HEA matrix, starting from elemental powders and as reinforcing material for composites was used pure graphite. The mechanical alloying process was carried out at different duration, in a high energy planetary ball mill, under argon atmosphere. The elemental powders alloying began after '5 hours of milling and was complete after 40 hours. The mechanical alloyed matrix and composite was pressed and heat treated under argon protection. The elemental powers were investigated for physical - technological properties, and by X-ray diffraction and scanning electron microscopy. Phase pressing operation was realized with a hydraulic press and the applied pressure was progressive. The sintering process was carried out at 850°C for 2 h. The X-ray diffraction revealed that the MA process resulted in solid solutions formation and also revealed body- centred cubic (BCC) and face-centred cubic (FCC) structures with average grain size around 40 nm. In addition, nanoscale particles were highlighted by scanning electron microscopy, as well as the homogeneity of the chemical composition of the matrix and composite that was confirmed by EDX microanalysis. It was noted that HEA matrix and HEA composites were processed with a high degree of compaction and with a quite large capacity of mixed powder densification (around 70%).

  10. Effect of time and temperature on grain size of V and V-Cr-Ti alloys

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Rink, D.L. [Argonne National Lab., IL (United States)

    1996-10-01

    Grain growth studies were conducted to evaluate the effect of time and temperature on the grain size of pure V, V-4 wt.%Cr-4 wt.%Ti, and V-5 wt.%Cr-5 wt.%Ti alloys. The temperatures used in the study were 500, 650, 800, and 1000{degrees}C, and exposure times ranged between 100 and {approx}5000 h. All three materials exhibited negligible grain growth at 500, 650, and 800{degrees}C, even after {approx}5000 h. At 1000{degrees}C, pure V showed substantial grain growth after only 100 h, and V-4Cr-4Ti showed growth after 2000 h, while V-5Cr-5Ti showed no grain growth after exposure for up to 2000 h.

  11. 800米跑的供能特点及其体能训练初探%The primary exploration of the energy supplying's characteristic and stamina training in the 800 meters race

    Institute of Scientific and Technical Information of China (English)

    毛海峰; 刘显东

    2007-01-01

    800米跑是田径运动难度最大的体能类极限下强度项目.现从体能类项目训练的根本点出发,运用生物化学的原理,结合当今田径发展的新特点,对800米跑的供能特点进行了深入地分析.认为,随着800米跑成绩的不断提高,其速度水平的不断提高,供能方式也在发生着变化,无氧代谢供能所占的比例已经越来越大.因此800米跑运动员的在比赛季节的训练也就越来越多的以元氧代谢训练为主.虽然有氧代谢供能在800米跑中只占所需能量的很少一部分,却是消除体内乳酸的重要手段.对提高800米跑运动成绩有效途径进行探索,以期对800米跑运动员的训练有所帮助.

  12. Alloying and Casting Furnace for Shape Memory Alloys Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The concept in the proposed project is to create a melting, alloying and casting furnace for the processing titanium based SMA using cold crucible techniques. The...

  13. Laser surface alloying of aluminium-transition metal alloys

    Directory of Open Access Journals (Sweden)

    Almeida, A.

    1998-04-01

    Full Text Available Laser surface alloying has been used as a tool to produce hard and corrosion resistant Al-transition metal (TM alloys. Cr and Mo are particularly interesting alloying elements to produce stable highstrength alloys because they present low diffusion coefficients and solid solubility in Al. To produce Al-TM surface alloys a two-step laser process was developed: firstly, the material is alloyed using low scanning speed and secondly, the microstructure is modified by a refinement step. This process was used in the production of Al-Cr, Al-Mo and Al-Nb surface alloys by alloying Cr, Mo or Nb powder into an Al and 7175 Al alloy substrate using a CO2 laser. This paper presents a review of the work that has been developed at Instituto Superior Tecnico on laser alloying of Al-TM alloys, over the last years.

    En el presente trabajo se estudia la aleación superficial mediante láser de aluminio con metales de transición. El cromo y el molibdeno son particularmente interesantes porque producen aleaciones de alta resistencia y por el bajo coeficiente de difusión y solución sólida en aluminio. Para producir estas aleaciones se ha seguido un procedimiento desarrollado en dos partes. En primer lugar, el material se alea usando una baja velocidad de procesado y en segundo lugar la estructura se modifica mediante un refinamiento posterior. Este procedimiento se ha empleado en la producción de aleaciones Al-Cr, Al-Mo y Al-Nb mediante aleación con láser de CO2 de polvos de Cr, Mo o Nb en aluminio y la aleación 7175. Este trabajo es una revisión del desarrollado en el Instituto Superior Técnico de Lisboa en los últimos años.

  14. Mechanical alloying of biocompatible Co-28Cr-6Mo alloy.

    Science.gov (United States)

    Sánchez-De Jesús, F; Bolarín-Miró, A M; Torres-Villaseñor, G; Cortés-Escobedo, C A; Betancourt-Cantera, J A

    2010-07-01

    We report on an alternative route for the synthesis of crystalline Co-28Cr-6Mo alloy, which could be used for surgical implants. Co, Cr and Mo elemental powders, mixed in an adequate weight relation according to ISO Standard 58342-4 (ISO, 1996), were used for the mechanical alloying (MA) of nano-structured Co-alloy. The process was carried out at room temperature in a shaker mixer mill using hardened steel balls and vials as milling media, with a 1:8 ball:powder weight ratio. Crystalline structure characterization of milled powders was carried out by X-ray diffraction in order to analyze the phase transformations as a function of milling time. The aim of this work was to evaluate the alloying mechanism involved in the mechanical alloying of Co-28Cr-6Mo alloy. The evolution of the phase transformations with milling time is reported for each mixture. Results showed that the resultant alloy is a Co-alpha solid solution, successfully obtained by mechanical alloying after a total of 10 h of milling time: first Cr and Mo are mechanically prealloyed for 7 h, and then Co is mixed in for 3 h. In addition, different methods of premixing were studied. The particle size of the powders is reduced with increasing milling time, reaching about 5 mum at 10 h; a longer time promotes the formation of aggregates. The morphology and crystal structure of milled powders as a function of milling time were analyzed by scanning electron microscopy and XR diffraction. PMID:20364362

  15. Research on the Training of 800-meter Run in Colleges and University%普通高校高水平田径运动员800m训练方法的研究

    Institute of Scientific and Technical Information of China (English)

    陈杰; 王波

    2008-01-01

    采用文献资料法、实验法、数理统计法等方法,以普通高校高水平田径运动800m跑训练方法为研究内容,在对800m跑技术结构、能量供应特点进行全面分析的基础上,提出了具有针对性的训练方法,旨在为提高高水平800m跑运动员的运动成绩提供理论与实践依据.

  16. 浅析800m跑的供能特点及其训练手段%On Energy - Supplying Characteristics and Training Method of 800- meter Race

    Institute of Scientific and Technical Information of China (English)

    胡俊; 杨绍昌

    2002-01-01

    通过分析800m跑的特点,从800m跑的供能角度提出800m跑训练应充分挖掘磷酸原供能的潜力,提高有氧代谢供能的质量和粮酵解供能能力,以及处理好速度、力量和速度耐力三者之间关系的训练方法.

  17. Influence of Breathing Methods for College Athletes 800m, 1000m Record%呼吸方法对大学生运动员800m、1000m成绩的影响

    Institute of Scientific and Technical Information of China (English)

    孙志新; 张健; 王厚雷

    2015-01-01

    现阶段800m、1000m是我国中小学的体育达标项目,同时也是我国高校的体能测试项目,即作为国家学生体质测试标准将 1000m(男生)与 800m(女生)作为测试指标之一, 1000m(男生)与800m(女生)测试在高校是必修课,学校将其作为国家学生体质测试标准的测试指标.在体育课的考核内容在多年的教学实践中发现,学生的参与少且抵触情绪大,使1000m(男生)与800m(女生)的测试对测试学生来说是一件很头疼的事情.本研究以聊城大学田径队甲组运动员为例,对大学生运动员 800m、1000m跑呼吸方法的进行研究,为 800、1000米跑提供科学的呼吸理论依据.%At this stage 800m, 1000 meters is our country elementary and middle schools sports standard project, is also our country university physical test project, namely the national student physique test standards will be 1000 meters (boys) and 800 meters (female) as one of the test index, 1000 meters (boys) and 800 meters (female) test is a required course in the University, the school will serve as a national student fitness test standard test index. As physical education assessment content found in many years of teaching practice, the students' participation is less and the resentment, the 1000 meters (boys) and 800 meters (female) test is a very difficult thing to test students. In this paper, a total of athletes of Liaocheng University track and field team as an example, research on college athletes in 800, 1000 meter run breathing method, to provide breathing the scientific theoretical basis for the 800, 1000 meter run.

  18. Damping Property of Supersaturated ZnAl27Ce Alloy duringNatural Aging

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The microstructures and damping property of supersaturated ZnAl27Ce alloy during natural aging have been investigated. H-800 TEM was mainly used to research the microstructures. The relationship between microstructure and damping property was primarily studied. The results showed that solution plus natural aging was the best heat treatment, which could improve the damping property. Both continuous precipitation and cellular reaction occurred during the aging. Continuous precipitation follows the sequence: β→spherical GP zones→elliptical GP zones→intermediate phase R→η. The cellular reaction can be written as follows: β→α+η+ε.

  19. Annealing Effect of Magnetostriction in Fe49Co49V2 Alloy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Research Institute of Industrial Science & Technology, P.O.Box 135 Pohang, 790-600, Korea A Fe49Co49V2 alloy was annealed at 500, 750, 800 and 900℃. The magnetostriction was measured by Michelson laser interferometer to receive the feedback signal of OPL variation. With the increase of annealing temperature, the grain size of texture in samples increases due to the recrystallization. Magnetostriction of 2× 10-6 at H=60 Oe increases up to 38 × 10-6 at annealing temperature of 900C, suggesting that the magnetostrictive characteristics are improved by the microstructural modification.

  20. Superplastic-like deformation in some solid solution alloys. [FeNiCr; AlMg

    Energy Technology Data Exchange (ETDEWEB)

    Korhonen, M.A.; Wilson, H.; Kuo, R.C.; Li Cheyu (Dept. of Materials Science and Engineering, Cornell Univ., Ithaca, NY (USA))

    1991-05-15

    The stress relaxation and tensile test data of Incoloy 800H and Al-4.6%Mg are described at temperatures where the contribution of grain boundary sliding to flow is significant. It is shown that in the presence of grain boundary sliding the whole range of behavior, from ordinary creep to superplastic-like flow, can be exhibited in the same metals, showing that the strain rate sensitivity increases with decreasing grain size or increasing temperature in the chosen temperature range. The effect of solute hardening on the flow behaviour of solid solution alloys in the presence of grain boundary sliding is also discussed. (orig.).

  1. Furnace bottom rise mechanism in preparation of Al-Si alloys by electrothermal process

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The experiments of preparation of Al-Si alloys by electrothermal process were carried out respectively in 20 kW, 100 kW and 1 800 kW DC arc furnaces. The mechanism of furnace bottom rise was studied.It was found that the bottom rise can be divided into three types, including the low bottom temperature, abnormal reducing reaction and carbide deposition. The furnace bottom rise is related to the carbon ratio of the briquet, the heating speed of the briquet and the parameters and operation of furnace.

  2. Crystallization and soft magnetic properties of rapidly solidified Fe73.5Nb3Cu1Si22.5-XBX (X=5, 9, 10, 11.25, 19) alloys

    International Nuclear Information System (INIS)

    The metalloids Si and B in the melt-spun Fe73.5Nb3Cu1Si22.5-XBX (X=5, 9, 10, 11.25, 19) alloys play a major role in their crystallization and magnetic behaviour. In the present work, the effect of nanocrystallization on the transport properties was studied using thermal variation of electrical resistivity. An X-ray diffractogram study showed that the formation of different phases was controlled by the metalloid content in the alloy. Nanocrystalline α-Fe(Si) and/or Fe3Si particles were formed in all the measured alloys except the alloy with 19 at% boron where α-Fe phase appeared. The lattice parameter as well as Si content within α-Fe(Si) was also found to depend on the metalloid content of the alloy. The Debye temperature was derived from thermal electrical resistivity study and was found to depend on the metalloid content of the alloys. However, Curie temperature of these alloys was not strongly dependent on the metalloid. The formation of α-Fe(Si) and/or Fe3Si nanoparticles was responsible for the superior soft magnetic properties of the 9 at% boron alloy annealed around 800 K. The early appearance of boride phases, which have high magnetocrystalline anisotropy, was the cause of deterioration in soft magnetic properties in X=5, 10, 11.25 and 19 alloys

  3. Dislocation Formation in Alloys

    Science.gov (United States)

    Minami, Akihiko; Onuki, Akira

    2006-05-01

    An interaction between dislocations and phase transitions is studied by a phase field model both in two and three dimensional systems. Our theory is a simple extension of the traditional linear elastic theory, and the elastic energy is a periodic function of local strains which is reflecting the periodicity of crystals. We find that the dislocations are spontaneously formed by quenching. Dislocations are formed from the interface of binary alloys, and slips are preferentially gliding into the soft metals. In three dimensional systems, formation of dislocations under applied strain is studied in two phase state. We find that the dislocation loops are created from the surface of hard metals. We also studied the phase separation above the coexisting temperature which is called as the Cottrell atmosphere. Clouds of metals cannot catch up with the motion of dislocations at highly strained state.

  4. Lead telluride alloy thermoelectrics

    Directory of Open Access Journals (Sweden)

    Aaron D. LaLonde

    2011-11-01

    Full Text Available The opportunity to use solid-state thermoelectrics for waste heat recovery has reinvigorated the field of thermoelectrics in tackling the challenges of energy sustainability. While thermoelectric generators have decades of proven reliability in space, from the 1960s to the present, terrestrial uses have so far been limited to niche applications on Earth because of a relatively low material efficiency. Lead telluride alloys were some of the first materials investigated and commercialized for generators but their full potential for thermoelectrics has only recently been revealed to be far greater than commonly believed. By reviewing some of the past and present successes of PbTe as a thermoelectric material we identify the issues for achieving maximum performance and successful band structure engineering strategies for further improvements that can be applied to other thermoelectric materials systems.

  5. The characteristics of unidirectional solidified Ni-Al-Mo alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ishak, M. [Department of Mechanical Engineering, University of Tokushima, Tokushima (Japan); Takagi, H. [Faculty of Mechanical Engineering, Universiti Malaysia Pahang, Pekan, Pahang (Malaysia)

    2012-05-15

    The material composite was fabricated by the unidirectional solidification method in the eutectic composition alloy. Performing unidirectional solidification of Ni-Al-Mo alloy in eutectic composition produces {gamma} phase -Ni and {gamma}' phase-Ni{sub 3}Al as a matrix, and the phase-Mo growth into fibrous and lamellar-like structure. The aim of this research was to study the characteristics of Ni-Al-Mo after various heat treatment conditions. The specimens were solution-treated at temperatures of 1180 C and 1280 C, followed by water quenching. In addition, aging treatments were carried out at various temperatures (from 700 C to 1000 C) and at different time durations. The microstructure, mechanical properties and characteristics of non-treated, solution-treated and aging specimens were investigated. It was found that the mechanical properties of unidirectional solidified Ni-Al-Mo can be improved by solution treatment whilst the strength through performing an aging treatment. The optimized conditions were at 1280 C and 4 hours for water quenching (solution treatment), followed by an aging process at 800 C and 4 hours. These treatments led to an increase of mechanical properties due to uniformly precipitations of finely dispersed {gamma}' phase-Ni{sub 3}Al throughout the specimens. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Alloy SCR-3 resistant to stress corrosion cracking

    International Nuclear Information System (INIS)

    Austenitic stainless steel is used widely because the corrosion resistance, workability and weldability are excellent, but the main fault is the occurrence of stress corrosion cracking in the environment containing chlorides. Inconel 600, most resistant to stress corrosion cracking, is not necessarily safe under some severe condition. In the heat-affected zone of SUS 304 tubes for BWRs, the cases of stress corrosion cracking have occurred. The conventional testing method of stress corrosion cracking using boiling magnesium chloride solution has been problematical because it is widely different from actual environment. The effects of alloying elements on stress corrosion cracking are remarkably different according to the environment. These effects were investigated systematically in high temperature, high pressure water, and as the result, Alloy SCR-3 with excellent stress corrosion cracking resistance was found. The physical constants and the mechanical properties of the SCR-3 are shown. The states of stress corrosion cracking in high temperature, high pressure water containing chlorides and pure water, polythionic acid, sodium phosphate solution and caustic soda of the SCR-3, SUS 304, Inconel 600 and Incoloy 800 are compared and reported. (Kako, I.)

  7. Effects of Friction Stir Welding Speed on AA2195 alloy

    Directory of Open Access Journals (Sweden)

    Lee Ho-Sung

    2016-01-01

    Full Text Available The application of friction stir welding (FSW to aerospace has grown rapidly due to the high efficiency and environmental friendly nature of the process. FSW is achieved by plastic flow of frictionally heated material in solid state and offers many advantages of avoiding hot cracking and limiting component distortion. Recently low density, high modulus and high strength AA2195 are used as substitute for conventional aluminum alloys since the weight saving is critical in aerospace applications. One of the problems for this alloy is weld metal porosity formation leading to hot cracking. Combination of FSW and AA2195 provides synergy effect to improve mechanical properties and weight saving of aerospace structure such as cryogenic fuel tanks for launch systems. The objective of this paper is to investigate the effect of friction stir welding speed on mechanical and microstructural properties of AA2195. The friction stir welded materials were joined with four different tool rotation speeds (350~800 rpm and five welding speeds (120~360 mm/min, which are the two prime welding parameters in this process.

  8. Growth of Hierarchically Structured High-Surface Area Alumina on FeCrAl Alloy Wires

    Directory of Open Access Journals (Sweden)

    Chandni Rallan

    2013-01-01

    Full Text Available The formation of metastable alumina phases due to the oxidation of commercial FeCrAl alloy wires (0.5 mm thickness at various temperatures and time periods has been examined. Samples were isothermally oxidised in air using a thermogravimetric analyzer (TGA. The morphology of the oxidised samples was analyzed using an Electronic Scanning Electron Microscope (ESEM and X-ray on the surface analysis was done using an Energy Dispersive X-Ray (EDX analyzer. The technique of X-Ray Diffraction (XRD was used to characterize the phase of the oxide growth. The entire study showed that it was possible to grow high-surface area gamma alumina on the FeCrAl alloy wire surfaces when isothermally oxidised above 800°C over several hours.

  9. ′ Precipitation and Growth Kinetics in Mechanically Alloyed Ni–Al

    Directory of Open Access Journals (Sweden)

    QingXin Tang

    2011-01-01

    Full Text Available The precipitation and growth kinetics of γ′ precipitates, which are strengthening factors in Ni-base oxide dispersion strengthened (ODS superalloys, were investigated. The cuboidal-type γ′ precipitates are formed in conventional arc-melted Ni–Al alloys, whereas spherical-type precipitates are formed in the mechanically alloyed (MAed specimens. The morphology is controlled by a lattice misfit between the γ′ precipitates and the matrix at the aging temperature of 800°C. The growth kinetics of the γ′ precipitates can be followed by Ostwald ripening. The Arrhenius plot yielded a lower activation energy for the solute atom diffusion in MAed specimens, which is attributed to their high dislocation density and nanosized grains.

  10. A molecular dynamics study on melting point and specific heat of Ni3Al alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Using the Embedding Atom Method(EAM)for highly undercooled Ni3Al alloy,the melting point and the specific heat were studied by a molecular dynamics simula-tion.The simulation of melting point was carried out by means of the sandwich method and the NVE ensemble method,and the results show a good agreement,whereas are larger than the experimental value of 1663 K.This difference is attrib-uted to the influence of surface melting on experimental results,which causes the smaller measurements compared with the thermodynamic melting point.The simulated specific heat of Ni3Al alloy weakly and linearly increases with the in-crease of undercooling in the temperature range from 800 K to 2000 K.

  11. A molecular dynamics study on melting point and specific heat of Ni3Al alloy

    Institute of Scientific and Technical Information of China (English)

    YANG Hong; L(U) YongJun; CHEN Min; GUO ZengYuan

    2007-01-01

    Using the Embedding Atom Method (EAM) for highly undercooled Ni3Al alloy, the melting point and the specific heat were studied by a molecular dynamics simulation. The simulation of melting point was carried out by means of the sandwich method and the NVE ensemble method, and the results show a good agreement, whereas are larger than the experimental value of 1663 K. This difference is attributed to the influence of surface melting on experimental results, which causes the smaller measurements compared with the thermodynamic melting point. The simulated specific heat of Ni3Al alloy weakly and linearly increases with the increase of undercooling in the temperature range from 800 K to 2000 K.

  12. Out-of-pile chemical compatibility of Pb-Bi eutectic alloy with graphite

    International Nuclear Information System (INIS)

    Lead Bismuth eutectic alloy (Pb: 55.5 wt.%, Bi: 44.5 wt.%) is a potential candidate coolant material for high-temperature reactors because of its low melting point (124 C), high thermal conductivity, heat capacity, and better neutronic properties. Out-of-pile chemical compatibility studies of this coolant with graphite (coolant channel) have been carried out by isothermal annealing of the liquid alloy in a graphite crucible at 800, 900, 1000, and 1100 C for times ranging from 100 h to 1000 h. Formation of a reaction layer is observed. The growth rate of the reaction layer follows a parabolic law. Reaction layer thicknesses of 61.3 μm and 121 μm are estimated from the growth rate vs. time relation after 1 year and 5 years respectively. The growth of the reaction layer is diffusion-controlled and the activation energy of the reaction is estimated to be 100 KJ/mol. (orig.)

  13. Production and characterization of Al-Mg matrix composite by mechanical alloying

    International Nuclear Information System (INIS)

    Mechanical alloying technique has been used to produce aluminium-based metal matrix composite powders. Powders of AI, Mg (5 wt %) and SiC (10-40 vol %) were used for the composite development. These powders were mechanically mixed in planetary ball mill (Retsch PM 200). The parameters used were 10:1 ball to powder weight ratio, 800 rpm speed of vial rotation and WC as grinding media. These milled powders were characterized by XRD. Mechanical alloying for the production of composite was achieved in only one step. There was decrease in density with the increase of contents of SiC. Compacted samples were sintered at 580 Co for 80 minutes. Maximum density achieved was 98.7% for composite containing 40 % SiC. Vickers hardness of consolidated samples was found to increase with the increase of SiC contents. (author)

  14. Micro segregation and homogenization treatments of uranium-niobium alloys (U-Nb)

    International Nuclear Information System (INIS)

    In the following sections micro segregation results in 0-3,6 wt% Nb and U-6,1 wt% Nb alloys casted in no consumable electrode arc furnace are presented. The micro segregation is studied qualitatively by optical microscopy and quantitatively by electron microprobe. The degree of homogenization has been measured after 800 and 850 deg C heat treatments in tubular resistive furnace. The microstructures after heat treatments are quantitatively analysed to check effects on the casting structures, mainly the variations in solute along the dendrite arm spacing. Some solidification phenomena are then discussed on reference to theoretical models of dendritic solidification , including microstructure and micro segregation. The experimental results are compared to theoretical on basis of initial and residual micro segregation after homogenization treatments. The times required for homogenization of the alloys are also discussed in function of the micro segregation from casting structures and the temperatures of the treatments. (author)

  15. Kinetics of σ-phase formation in equiatomic cold-rolled Fe–V alloys

    Energy Technology Data Exchange (ETDEWEB)

    Costa, B.F.O., E-mail: Benilde@ci.uc.pt [CEMDRX Department of Physics, University of Coimbra, Rua Larga, P-3004-516 Coimbra (Portugal); Cieslak, J.; Dubiel, S.M. [AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. A. Mickiewicza 30, PL-30-059 Krakow (Poland)

    2013-12-16

    The kinetics of α-to-σ phase transformation in equiatomic Fe–V cold-rolled alloys was studied by the Mössbauer spectroscopy (MS) and X-ray diffraction (XRD) techniques. The kinetics could be well-described in terms of the Johnson–Mehl–Avrami–Kolmogorov type equation. The activation energy has been determined as being 189 kJ mol{sup −1} and the Avrami exponent as close to 3. The σ-phase precipitation rate was found to be the highest at 800 °C. Prior to the formation of the σ-phase the ordered B2 phase was revealed, as a precursor of σ, by both MS and XRD techniques. - Highlights: • Kinetics of alpha-to-sigma phase formation in Fe–V alloys. • Activation energy for the sigma-phase formation. • B2 ordered phase is a precursor of the sigma-phase.

  16. Time dependency of the hydrophilicity and hydrophobicity of metallic alloys subjected to femtosecond laser irradiations

    International Nuclear Information System (INIS)

    Surfaces of metallic alloys were laser-processed with femtosecond laser pulses of 800 nm, with different power densities. The effect of time on the wettability of these surfaces was investigated. A multi-scale roughness made of undulations was created after the laser processing. This specific surface topography allowed the occurrence of a Wenzel's state. This state clearly explains the high hydrophilicity and hydrophobicity observed respectively one day after laser treatment and several days later. The change from hydrophilicity to hydrophobicity occurred over time and is due to surface chemistry modifications. The creation of new hydrophobic functional groups on aluminum alloy surface, for example, was proposed to be responsible for the hydrophobic behavior observed on these surfaces.

  17. Time dependency of the hydrophilicity and hydrophobicity of metallic alloys subjected to femtosecond laser irradiations

    Science.gov (United States)

    Bizi-bandoki, P.; Valette, S.; Audouard, E.; Benayoun, S.

    2013-05-01

    Surfaces of metallic alloys were laser-processed with femtosecond laser pulses of 800 nm, with different power densities. The effect of time on the wettability of these surfaces was investigated. A multi-scale roughness made of undulations was created after the laser processing. This specific surface topography allowed the occurrence of a Wenzel's state. This state clearly explains the high hydrophilicity and hydrophobicity observed respectively one day after laser treatment and several days later. The change from hydrophilicity to hydrophobicity occurred over time and is due to surface chemistry modifications. The creation of new hydrophobic functional groups on aluminum alloy surface, for example, was proposed to be responsible for the hydrophobic behavior observed on these surfaces.

  18. Determination and modeling of the thermodynamic properties of liquid calcium–antimony alloys

    International Nuclear Information System (INIS)

    The thermodynamic properties of Ca–Sb alloys were determined by emf measurements in a cell configured as Ca(s)|CaF2|Ca–Sb over the temperature range 550–830 °C. Activity coefficients of Ca and Sb, enthalpy, Gibbs free energy, and entropy of mixing of Ca–Sb alloys were calculated for xCa 2 associate, and the molecular interaction volume model (MIVM). For the first time, the MIVM was used successfully to model the activity coefficients of a system with high-melting intermetallics, reducing the number of fitting parameters necessary from 5 (regular associated model) to 2 (MIVM). From the interaction parameters optimized by fitting at 800 °C, the activity coefficient of Ca was predicted at 650 °C, with an average error of less than 0.6% in the emf value.

  19. An application of Au thin-film emissivity barrier on Ni alloy

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zhibin [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechincial University, Xi' an 710072 (China)], E-mail: huangzhibin83@163.com; Zhu Dongmei; Lou Fa; Zhou Wancheng [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechincial University, Xi' an 710072 (China)

    2008-12-30

    1000 nm-thick Au film was sputter-deposited on two groups of nickel alloy substrates, in which one group (Group A) was oxidated at 800 deg. C for 20 h to form a oxide film before coating gold while another group (Group B) was unoxidated. The gold thin-film is applied to serve as a low emissivity coating to reflect thermal radiation. The gold-coated samples were heated in air at 600 deg. C for 150 h to explore the effect of high-temperature environment on the emissivity of coated Au film. After heat-treatment, the average thermal emissivity at the wavelength of 3-14 {mu}m of Group B greatly increased from 0.18 to 0.82 while that of Group A only increased a little. The diffusion between Au and other nickel alloy elements at 600 deg. C also had been discussed in this paper.

  20. High-temperature steam oxidation kinetics of the E110G cladding alloy

    Science.gov (United States)

    Király, Márton; Kulacsy, Katalin; Hózer, Zoltán; Perez-Feró, Erzsébet; Novotny, Tamás

    2016-07-01

    In the course of recent years, several experiments were performed at MTA EK (Centre for Energy Research, Hungarian Academy of Sciences) on the isothermal high-temperature oxidation of the improved Russian cladding alloy E110G in steam/argon atmosphere. Using these data and designing additional supporting experiments, the oxidation kinetics of the E110G alloy was investigated in a wide temperature range, between 600 °C and 1200 °C. For short durations (below 500 s) or high temperatures (above 1065 °C) the oxidation kinetics was found to follow a square-root-of-time dependence, while for longer durations and in the intermediate temperature range (800-1000 °C) it was found to approach a cube-root-of-time dependence rather than a square-root one. Based on the results a new best-estimate and a conservative oxidation kinetics model were created.

  1. Influence of deformation and annealing on texture and anisotropy of the properties in VT23 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zakharchenko, I.G.; Ivasishin, O.M.; Ivanij, V.S.; Kshnyakin, V.S. (AN Ukrainskoj SSR, Kiev. Inst. Metallofiziki; Sumskij Gosudarstvennyj Pedagogicheskij Inst. (Ukrainian SSR))

    The effect of cold rolling and following heat treatment on development of texture and anisotropy of physical properties in sheets of VT23 titanium alloy is investigated. It is shown that decrease of elastic anisotropy of hot-rolled sheets of VT23 alloy can be assured by cold rolling. Annealings at temperatures up to 500 deg C do not bring about essential changes in anisotropy. But orientated ..cap alpha.. reversible ..beta.. - transformations at annealing up to 750-800 deg C promoting development of prismatic and pyramidal components of texture result in increase of anisotropy of elastic properties. Essential decrease of anisotropy value of Young modulus takes place after heating in the ..beta..-region.

  2. Structure and properties of ceramic coatings formed on aluminum alloys by microarc oxidation

    Institute of Scientific and Technical Information of China (English)

    LIU Wan-hui; BAO Ai-lian; LIU Rong-xiang; WU Wan-liang

    2006-01-01

    The thick and hard ceramic coatings were deposited on 2024 Al alloy by microarc oxidation in the electrolytic solution.Microstructure, phase composition and wear resistance of the oxide coatings were investigated by SEM, XRD and friction and wear tester. The microhardness and thickness of the oxide coatings were measured. The results show that the ceramic coating is mainly composed of α-Al2O3 and γ-Al2O3. During oxidation, the temperature in the microarc discharge channel is very high to make the local coating molten. From the surface to interior of the coating, microhardness increases gradually. The microhardness of the ceramic coating is HV1 800, and the microarc oxidation coatings greatly improve the antiwear properties of aluminum alloys.

  3. Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings - phase II

    Energy Technology Data Exchange (ETDEWEB)

    Blough, J.L.; Stanko, G.J. [Foster Wheeler Development Corp., Livingston, NJ (United States)

    1996-08-01

    In Phase I a variety of developmental and commercial tubing alloys and claddings were exposed to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. Phase II (in situ testing) has exposed samples of 347, RA-8511, HR3C, 253MA, Fe{sub 3}Al + 5Cr, 310 modified, 800HT, NF 709, 690 clad, and 671 clad for over 10,000 hours to the actual operating conditions of a 250-MW coal-fired boiler. The samples were installed on an air-cooled, retractable corrosion probe, installed in the reheater cavity, and controlled to the operating metal temperatures of an existing and advanced-cycle coal-fired boiler. Samples of each alloy will be exposed for 4000, 12,000, and 16,000 hours of operation. The results will be presented for the metallurgical examination of the corrosion probe samples after 4000 hours of exposure.

  4. Emissivity measurements on aeronautical alloys

    Energy Technology Data Exchange (ETDEWEB)

    Campo, L. del, E-mail: leire.del-campo@cnrs-orleans.f [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Perez-Saez, R.B., E-mail: raul.perez@ehu.e [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao (Spain); Gonzalez-Fernandez, L. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Esquisabel, X.; Fernandez, I. [Industria de Turbo Propulsores, S.A., Planta de Zamudio, Edificio 300, 48170 Zamudio, Bizkaia (Spain); Gonzalez-Martin, P. [Industria de Turbo Propulsores, S.A., Parque empresarial San Fernando, Avda. Castilla 2, 28830 San Fernando de Henares, Madrid (Spain); Tello, M.J. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao (Spain)

    2010-01-21

    The emissivity of three Ni and Co based aeronautical alloys is analyzed in this paper. These alloys are employed in high temperature environments whenever good corrosion resistance, high temperature resistance and high strength are essential. Thus, apart from the aeronautical industry, these alloys are also used in other technological applications, as for example, aerospace, nuclear reactors, and tooling. The results in this paper extend the emissivity data for these alloys available in the literature. Emissivity dependence on the radiation wavelength (2-22 {mu}m), sample temperature (200-650 {sup o}C) and emission angle (0-85{sup o}) has been investigated. In addition, the effect of surface finish and oxidation has also been taken into consideration. The data in this paper have several applications, as temperature measurement of a target by pyrometry, low observability of airplanes and thermal radiation heat transfer simulation in airplane nozzles or furnaces.

  5. Auger electron spectroscopy of alloys

    International Nuclear Information System (INIS)

    This thesis describes how the surface compositions of some alloys can be determined by Auger Electron Spectroscopy (AES). The motivation for this research and the reasons for the choice of alloy systems studied are formulated. The theoretical background of AES is briefly discussed and the apparatus used and the experimental procedures applied are described. Four alloy systems have been investigated in this thesis - Ni-Cu and Pd - Ag (consisting of a component active in most cataytic reactions - Ni and Pd; and a component which is almost inactive for a number of reactions - Cu and Ag) and Pt - Pd and Pt-Ir (consisting of two active components). Knowledge of the surface composition of the various alloy systems is shown to be essential for the interpretation of catalytic results. (Auth./C.F.)

  6. Diffusion Welding of Alloys for Molten Salt Service - Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Denis Clark; Ronald Mizia

    2012-05-01

    The present work is concerned with heat exchanger development for molten salt service, including the proposed molten salt reactor (MSR), a homogeneous reactor in which the fuel is dissolved in a circulating fluid of molten salt. It is an outgrowth of recent work done under the Next Generation Nuclear Plant (NGNP) program; what the two reactor systems have in common is an inherently safe nuclear plant with a high outlet temperature that is useful for process heat as well as more conventional generation The NGNP program was tasked with investigating the application of a new generation of nuclear power plants to a variety of energy needs. One baseline reactor design for this program is a high temperature, gas-cooled reactor (HTGR), which provides many options for energy use. These might include the conventional Rankine cycle (steam turbine) generation of electricity, but also other methods: for example, Brayton cycle (gas turbine) electrical generation, and the direct use of the high temperatures characteristic of HTGR output for process heat in the chemical industry. Such process heat is currently generated by burning fossil fuels, and is a major contributor to the carbon footprint of the chemical and petrochemical industries. The HTGR, based on graphite fuel elements, can produce very high output temperatures; ideally, temperatures of 900 C or even greater, which has significant energy advantages. Such temperatures are, of course, at the frontiers of materials limitations, at the upper end of the performance envelope of the metallic materials for which robust construction codes exist, and within the realm of ceramic materials, the fabrication and joining of which, on the scale of large energy systems, are at an earlier stage of development. A considerable amount of work was done in the diffusion welding of materials of interest for HTGR service with alloys such as 617 and 800H. The MSR output temperature is also materials limited, and is projected at about 700 C

  7. Diffusion Welding of Alloys for Molten Salt Service - Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Denis Clark; Ronald Mizia; Piyush Sabharwall

    2012-09-01

    The present work is concerned with heat exchanger development for molten salt service, including the proposed molten salt reactor (MSR), a homogeneous reactor in which the fuel is dissolved in a circulating fluid of molten salt. It is an outgrowth of recent work done under the Next Generation Nuclear Plant (NGNP) program; what the two reactor systems have in common is an inherently safe nuclear plant with a high outlet temperature that is useful for process heat as well as more conventional generation The NGNP program was tasked with investigating the application of a new generation of nuclear power plants to a variety of energy needs. One baseline reactor design for this program is a high temperature, gas-cooled reactor (HTGR), which provides many options for energy use. These might include the conventional Rankine cycle (steam turbine) generation of electricity, but also other methods: for example, Brayton cycle (gas turbine) electrical generation, and the direct use of the high temperatures characteristic of HTGR output for process heat in the chemical industry. Such process heat is currently generated by burning fossil fuels, and is a major contributor to the carbon footprint of the chemical and petrochemical industries. The HTGR, based on graphite fuel elements, can produce very high output temperatures; ideally, temperatures of 900 °C or even greater, which has significant energy advantages. Such temperatures are, of course, at the frontiers of materials limitations, at the upper end of the performance envelope of the metallic materials for which robust construction codes exist, and within the realm of ceramic materials, the fabrication and joining of which, on the scale of large energy systems, are at an earlier stage of development. A considerable amount of work was done in the diffusion welding of materials of interest for HTGR service with alloys such as 617 and 800H. The MSR output temperature is also materials limited, and is projected at about 700

  8. 中师女生800 m跑的教学探讨%On teaching of the female students′800-meter running in normal school

    Institute of Scientific and Technical Information of China (English)

    朱海莲

    2001-01-01

    From the survey and analysis of the statistic achievements within the specific scope of ′97 five-year-system female students.the article put forward the enlightening teaching idea called “San Qiangdiao” and summarized ten teaching approaches of proof running based on year′s teaching parctice.The article would give help to optimize the teaching way,make the teaching of proof running interesting,and improve the student′s body fibre.%在上虞师范学校97届中师大专班女生800 m跑教学的特定范围内,通过书面调查、成绩统计分析,在多年体育教学实践的基础上,提出了“三强调”的启发性教学,积累了“十种耐力跑教学方法”.对教者发令,学者强应的教法可能有所帮助.从而改变了耐力跑枯燥乏味,学生不感兴趣的状况,全面促进了学生身体素质的提高.

  9. Corrosion Evaluation of Alloys and MCrAlX Coatings in Molten Carbonates for Thermal Solar Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Vidal, Judith C.; Noel, John; Weber, Jacob

    2016-12-01

    Stainless steels (SS) 310, 321, 347, Incoloy 800H (In800H), alumina-forming austenitic (AFA-OC6), Ni superalloy Inconel 625 (IN625), and MCrAlX (M: Ni, and/or Co; X: Y, Hf, Si, and/or Ta) coatings were corroded in molten carbonates in N2 and bone-dry CO2 atmospheres. Electrochemical tests in molten eutectics K2CO3-Na2CO3 and Na2CO3-K2CO3-Li2CO3 at temperatures higher than 600 degrees C were evaluated using an open-circuit potential followed by a potentiodynamic polarization sweep to determine the corrosion rates. Because the best-performing alloys at 750 degrees C were In800H followed by SS310, these two alloys were selected as the substrate material for the MCrAlX coatings. The coatings were able to mitigate corrosion in molten carbonates environments. The corrosion of substrates SS310 and In800H was reduced from ~2500 um/year to 34 um/year when coated with high-velocity oxyfuel (HVOF) NiCoCrAlHfSiY and pre-oxidized (air, 900 degrees C, 24 h, 0.5 degrees C/min) before molten carbonate exposure at 700 degrees C in bone-dry CO2 atmosphere. Metallographic characterization of the corroded surfaces showed that the formation of a uniform alumina scale during the pre-oxidation seems to protect the alloy from the molten carbonate attack.

  10. Laser welding of aluminium alloys

    OpenAIRE

    Forsman, Tomas

    2000-01-01

    This thesis treats laser welding of aluminium alloys from a practical perspective with elements of mathematical analysis. The theoretical work has in all cases been verified experimentally. The aluminium alloys studied are from the 5xxx and 6xxx groups which are common for example in the automotive industry. Aluminium has many unique physical properties. The properties which more than others have been shown to influence the welding process is its high reflection, high thermal conductivity, lo...

  11. Uranium-Based Cermet Alloys

    International Nuclear Information System (INIS)

    The paper describes certain features of dispersion-hardened uranium-based cermets. As possible hardening materials, consideration was given to UO2, UC, Al2O3, MgO and UBe13. Data were obtained on the behaviour of uranium alloys containing the above-mentioned admixtures during creep tests, short-term strength tests and cyclic thermal treatment. The corrosion resistance o f UBe13-based uranium alloys was also studied. )author)

  12. Friction surfacing of aluminium alloys

    OpenAIRE

    Pereira, Diogo Jorge O. A.

    2012-01-01

    Friction surfacing is a solid state joining process that has attracted much interest in the past decades. This technology allows joining dissimilar metallic materials while avoiding the brittle intermetallic formations, involving temperatures bellow melting point and producing like forged metal structures. Much research using different steels has been made but the same does not happen with aluminium alloys, specially using different aluminium alloys. Friction surface coatings using cons...

  13. EFFICACY OF SINGLE DOSE OF VAGINAL MISOPROSTOL 800 μg IN FIRST TRIMESTER ABORTION.

    Directory of Open Access Journals (Sweden)

    Gopal

    2013-04-01

    Full Text Available ABSTRACT: OBJECTIVES : To know the efficacy and outcome of single dose o f vaginal Misoprostol 800Ug in first trimester abortion. MATERIAL AND METHODS : This study was conducted over a period of 3 yrs at Adichunchanagir i institute of medical sciences. A total of 200 pregnant women upto 12 wks of gestation wanting termi nation of pregnancy was recruited in this study. The efficacy, outcome, and induction ab ortion interval was studied in these cases. RESULTS: In our case study 76% of the patients had complete a bortion with single dose of 800ug Misoprostol and 4 % underwent check curettage due to profuse bleeding and retained products in uterus on USG. 20% of the cases needed s econd dose of 200ug of Misoprostol. The mean induction to abortion interval was 11.38hrs. 9 6% of the patients had complete abortion with medical method and only 4% underwent surgical curettage due to profuse bleeding after the single dose. The mean haemoglobin prior to induc tion was 9.76gm% and post expulsion was 9.59gm % respectively. No statistical difference was noted .The incidence of side effects like nausea, vomiting and diarrhoea was minimal and tran sitory. No major complications noted. CONCLUSION: Vaginal PGE 1 analogue is very safe and effective method of term ination of first trimester pregnancy. Single high dose of vaginal Mis oprostol 800ug is found to be cost -effective with minimal side effects, shorter Induction Aborti on interval and a day care procedure with good success rate and can be adopted at community an d primary health care units to reduce the maternal morbidity and mortality in developing count ries like India due to unwanted pregnancies and unsafe abortions

  14. TEM microstructure investigations of aluminium alloys used for laser alloying

    Directory of Open Access Journals (Sweden)

    K. Labisz

    2012-12-01

    Full Text Available Purpose: In this paper there are presented results of Transmission Electron Microscope investigation concerning the structure of the AlSi7Cu4 cast aluminium alloy using for alloying and remelting with the high power diode laser (HPDL. There are also presented the results of the thermo-derivative analysis performed using the UMSA (Universal Metallurgical Simulator and Analyser device, allowing to determine the specific points of the solidifying alloy, what is helpful for phase determination occurred in this alloy. In this work especially the changes of the precipitation type, size and shape were determined.Design/methodology/approach: The investigations were performed using electron microscopy for the microstructure and phases determination. By mind of the transmission electron microscopy, especially selected area diffraction method appliance it was possible to determine the phases occurred in the alloy in the as cast state. The morphology and size of the Mg2Si was also possible to determine as well the lattice parameters for this phase.Findings: : The reason of this work was also to present the laser treatment technology, which will be used for further alloying and remelting with ceramic powders – especially carbides and oxides. Particularly the overview will be directed on the laser power to achieve good layer hardness for protection of this hot work tool steel from losing their work stability and to make the tool surface more resistant to action in external conditions. The structure of the surface laser tray changes in a way, that there are very high roughness of the surface zone and the flatness or geometry changes in an important manner, crucial for further investigation.Research limitations/implications: The aluminium samples were examined metallographically using transmission electron microscope with different image techniques.Practical implications: Developing of new technology with appliance of Al alloys, High Power Diode Laser and

  15. Clinical values of intraoperative indocyanine green fluorescence video angiography with Flow 800 software in cerebrovascular surgery

    Institute of Scientific and Technical Information of China (English)

    YE Xun; LIU Xing-ju; MA Li; LIU Ling-tong; WANG Wen-lei; WANG Shuo; CAO Yong

    2013-01-01

    Background Microscope-integrated near-infrared indocyanine green video angiography (ICG-VA) has been used in neurosurgery for a decade.This study aimed to assess the value of intraoperative indocyanine green (ICG) video angiography with Flow 800 software in cerebrovascular surgery and to discover its hemodynamic features and changes of cerebrovascular diseases during surgery.Methods A total of 87 patients who received ICG-VA during various surgical procedures were enrolled in this study.Among them,45 cases were cerebral aneurysms,25 were cerebral arteriovenous malformations (AVMs),and 17 were moyamoya disease (MMD).A surgical microscope integrating an infrared fluorescence module was used to confirm the residual aneurysms and blocking of perforating arteries in aneurysms.Feeder arteries,draining veins,and normal cortical vessels were identified by the time delay color mode of Flow 800 software.Hemodynamic parameters were recorded.All data were analyzed by SPSS version 18.0 (SPSS Inc.,USA).T-test was used to analyze the hemodynamic features of AVMs and MMDs,the influence on peripheral cortex after resection in AVMs,and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in MMDs.Results The visual delay map obtained by Flow 800 software had more advantages than the traditional playback mode in identifying the feeder arteries,draining veins,and their relations to normal cortex vessels.The maximum fluorescence intensity (MFI) and the slope of ICG fluorescence curve of feeder arteries and draining veins were higher than normal peripheral vessels (MFI:584.24±85.86 vs.382.94±91.50,slope:144.95±38.08 vs.69.20±13.08,P <0.05).The artefiovenous transit time in AVM was significantly shorter than in normal cortical vessels ((0.60±0.27) vs.(2.08±1.42) seconds,P <0.05).After resection of AVM,the slope of artery in the cortex increased,which reflected the increased cerebral flow.In patients with MMD,after STA-MCA bypass,cortex perfusion of

  16. Self-seeded lasing in ionized air pumped by 800 nm femtosecond laser pulses

    CERN Document Server

    Liu, Yi; Point, Guillaume; Houard, Aurélien; Mysyrowicz, André

    2013-01-01

    We report on the lasing in air and pure nitrogen gas pumped by a single 800 nm femtosecond laser pulse. Depending on gas pressure, incident laser power and beam convergence, different lasing lines are observed in the forward direction with rapid change of their relative intensities. The lines are attributed to transitions between vibrational and rotational levels of the first negative band of the singly charged nitrogen molecule-ion. We show that self-seeding plays an important role in the observed intensity changes.

  17. The effects of Gamma radiation on a PBX containing TATB and the fluoropolymer FK-800

    OpenAIRE

    Connors, S C

    2014-01-01

    The polymer bonded explosive TCV is analogous to PBX compositions used in some nuclear weapons where the PBX will be exposed to high energy ionising gamma radiation. It is therefore important to study how gamma radiation affects the mechanical and chemical properties of the PBX. In this study 60Co was used to irradiate samples of the TCV, its FK-800 binder and TATB explosive filler, at 37.5 °C, to total doses up to 200 kGy in air and under vacuum. Post irradiation analysis consisted of mec...

  18. Orbital and millennial Antarctic climate variability over the past 800,000 years.

    Science.gov (United States)

    Jouzel, J; Masson-Delmotte, V; Cattani, O; Dreyfus, G; Falourd, S; Hoffmann, G; Minster, B; Nouet, J; Barnola, J M; Chappellaz, J; Fischer, H; Gallet, J C; Johnsen, S; Leuenberger, M; Loulergue, L; Luethi, D; Oerter, H; Parrenin, F; Raisbeck, G; Raynaud, D; Schilt, A; Schwander, J; Selmo, E; Souchez, R; Spahni, R; Stauffer, B; Steffensen, J P; Stenni, B; Stocker, T F; Tison, J L; Werner, M; Wolff, E W

    2007-08-10

    A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage 20.2, approximately 800,000 years ago. Experiments performed with an atmospheric general circulation model including water isotopes support its temperature interpretation. We assessed the general correspondence between Dansgaard-Oeschger events and their smoothed Antarctic counterparts for this Dome C record, which reveals the presence of such features with similar amplitudes during previous glacial periods. We suggest that the interplay between obliquity and precession accounts for the variable intensity of interglacial periods in ice core records.

  19. Intergranular fracture of lithium fluoride-22 percent calcium fluoride hypereutectic salt at 800 K

    Science.gov (United States)

    Raj, Subramanium V.; Whittenberger, J. Daniel

    1990-01-01

    Substantial strain-hardening was noted during the initial stages of deformation in constant-velocity compression tests conducted on as-cast samples of the LiF-22 mol pct CaF2 hypereutectic salt at 800 K. The deformed specimens exhibited extensive grain-boundary cracking and cavitation, suggesting that such cracking, in conjunction with interfacial sliding, is important for cavity nucleation at grain boundaries and at the LiF-CaF2 interfaces. Cavity growth and interlinkage occur through the preferential failure of the weaker LiF phase.

  20. The K^*_0(800) scalar resonance from Roy-Steiner representations of pi K scattering

    OpenAIRE

    Descotes-Genon, S.; Moussallam, B.

    2006-01-01

    We discuss the existence of the light scalar meson K^*_0(800) (also called kappa) in a rigorous way, by showing the presence of a pole in the pi K --> pi K amplitude on the second Riemann sheet. For this purpose, we study the domain of validity of two classes of Roy-Steiner representations in the complex energy plane. We prove that one of them is valid in a region sufficiently broad in the imaginary direction. From this representation, we compute the l=0 partial wave in the complex plane with...

  1. Subcarrier Wave Quantum Key Distribution in Telecommunication Network with Bitrate 800 kbit/s

    Directory of Open Access Journals (Sweden)

    Gleim A.V.

    2015-01-01

    Full Text Available In the course of work on creating the first quantum communication network in Russia we demonstrated quantum key distribution in metropolitan optical network infrastructure. A single-pass subcarrier wave quantum cryptography scheme was used in the experiments. BB84 protocol with strong reference was chosen for performing key distribution. The registered sifted key rate in an optical cable with 1.5 dB loss was 800 Kbit/s. Signal visibility exceeded 98%, and quantum bit error rate value was 1%. The achieved result is a record for this type of systems.

  2. Subcarrier Wave Quantum Key Distribution in Telecommunication Network with Bitrate 800 kbit/s

    Science.gov (United States)

    Gleim, A. V.; Nazarov, Yu. V.; Egorov, V. I.; Smirnov, S. V.; Bannik, O. I.; Chistyakov, V. V.; Kynev, S. M.; Anisimov, A. A.; Kozlov, S. A.; Vasiliev, V. N.

    2015-09-01

    In the course of work on creating the first quantum communication network in Russia we demonstrated quantum key distribution in metropolitan optical network infrastructure. A single-pass subcarrier wave quantum cryptography scheme was used in the experiments. BB84 protocol with strong reference was chosen for performing key distribution. The registered sifted key rate in an optical cable with 1.5 dB loss was 800 Kbit/s. Signal visibility exceeded 98%, and quantum bit error rate value was 1%. The achieved result is a record for this type of systems.

  3. Inherent safety of advanced nuclear engineering based on BN-800 - type fast reactors

    International Nuclear Information System (INIS)

    Considerations based on the prolonged experience of fast reactor operations exhibiting outlook application of reactors on a basis of BN-800 with sodium coolant are given. Reliability and safety of the block are supported by the probability analysis of safety in the content of engineering project. Conversion on the reactor core with nitride fuel will significantly raise a possibility to conform to safety and nonproliferation of fission materials needs. The suggested optimum variant for reactor core on a basis of nitride fuel is advanced

  4. The Beckman DxI 800 prolactin assay demonstrates superior specificity for monomeric prolactin.

    LENUS (Irish Health Repository)

    Byrne, Brendan

    2010-02-01

    Commercially available prolactin immunoassays detect macroprolactin to variable degrees. Best practice requires laboratories to assess the cross-reactivity of their prolactin assay with macroprolactin, and where appropriate, introduce a screen for the presence of macroprolactin. Our policy has been to reanalyse hyperprolactinaemic samples following polyethylene glycol (PEG) precipitation and to report the resultant value as the monomeric prolactin content of the sample. The goal of this study was to determine the need to continue PEG precipitation when prolactin measurements with the Wallac AutoDELFIA were replaced by the Beckman DxI 800.

  5. Two body photodisintegration of the deuteron from 100 to 800 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, R.; Annand, J.R.M.; Anthony, I. [Glasgow Univ. (United Kingdom). Dept. of Physics and Astronomy; Ahrens, J.; Beck, R. [Mainz Univ. (Germany). Inst. fuer Kernphysik; Braghieri, A.; Pedroni, P. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy); Altieri, S. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy)]|[Pavia Univ. (Italy). Ist. di Fisica Nucleare; Audit, G.; D`Hose, N. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee] [and others

    1996-01-01

    The total and the differential cross sections for the D({gamma},p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30 deg-160 deg in 10 deg intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and the results compared with some recent theoretical calculations. (author). Submitted to Nuclear Physics, B (NL); 23 refs.

  6. Forward dispersion relations for pion-kaon scattering and the K*0(800) resonance

    CERN Document Server

    Rodas, A

    2016-01-01

    We review our recent analysis of $\\pi K$ scattering data in terms of forward dispersion relations, and also present the parameters of the strange resonances. This work consists of fits to the data that are constrained to satisfy analyticity requirements. The method yields a set of simple and consistent parameterizations that are compatible with forward dispersion relations up to 1.6 GeV while still describing the data. We also obtain the pole parameters of the $K^*_0(800)$ and the $K^*(892)$ resonances.

  7. Extremely premature (⩽ 800 g) schoolchildren: multiple areas of hidden disability

    OpenAIRE

    Whitfield, M; Grunau, R.; Holsti, L.

    1997-01-01

    AIM—To examine the functional abilities of extremely low birthweight (ELBW, ⩽ 800 g) children at school age compared with full term children.
METHODS—ELBW children (n=115) in a geographically defined regional cohort born between 1974 and mid-1985 (comprising 96% of 120 survivors of 400 ELBW infants admitted to the Provincial Tertiary neonatal intensive care unit), were compared with (n = 50) children of comparable age and sociodemographic status. Each child was categorised by the pattern and ...

  8. Nonlinear refraction properties of nickel oxide thin films at 800 nm

    Science.gov (United States)

    de Melo, Ronaldo P.; da Silva, Blenio J. P.; dos Santos, Francisco Eroni P.; Azevedo, A.; de Araújo, Cid B.

    2009-11-01

    Measurements of the nonlinear refractive index, n2, of nickel oxide films prepared by controlled oxidation of nickel films deposited on substrates of soda-lime glass are reported. The structure and morphology of the samples were characterized by scanning electron microscopy, atomic force microscopy, and x-ray diffractometry. Samples of excellent optical quality were prepared. The nonlinear measurements were performed using the thermally managed eclipse Z-scan technique at 800 nm. A large value of n2≈10-12 cm2/W and negligible nonlinear absorption were obtained.

  9. Load relaxation studies of grain boundary sliding in Incoloy 800H

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, H.; Hannula, S.P.; Korhonen, M.A.; Suzuki, H.; Li, C.Y (Cornell Univ., Ithaca, NY (USA))

    Load relaxation tests were performed on Incoloy 800H at elevated temperatures as a function of prior plastic deformation. The log stress vs. log strain rate curves obtained exhibit the typical sigmoidal shape predicted by current theories. A stress enhancement factor with a value near 0.7 can be estimated based on limiting stress values both at the high and low strain rate ends. The results of data analysis yielded long grain boundary stress vs. log grain boundary sliding rate curves. These curves are found to show grain matrix-like characteristics. The significance of these results is discussed in terms of a state variable theory.

  10. Rydberg states in the strong field ionization of hydrogen by 800, 1200 and 1600 nm lasers

    International Nuclear Information System (INIS)

    We study the population of Rydberg excited states in the strong field interaction of atomic hydrogen with 800, 1200 and 1600 nm laser pulses. The total excitation probability displays strong out-of-phase modulation with respect to the weak modulation in the total ionization probability as the laser intensity is increased. The results are explained in terms of channel closing, to demonstrate multiphoton ionization features in the strong tunnel ionization regime. We also explain the stability of high Rydberg states in strong laser fields in contrast to other previous ionization stabilization models. (paper)

  11. 俄罗斯完成BN-800快堆的安全分析

    Institute of Scientific and Technical Information of China (English)

    张焰(译); 伍浩松(校)

    2012-01-01

    【圣彼得堡原子能设计院网站2012年8月29日报道】俄罗斯圣彼得堡原子能设计院(Atomenergoproekt)的专家近日完成了对在建的别洛雅尔斯克4号机组进行的一项综合安全分析。别洛雅尔斯克4号机组是一台BN-800快堆机组。

  12. Atmospheric lateral and longitudinal turbulent length scales (measured at 600 to 800 meters above grade level)

    Science.gov (United States)

    Cliff, W. C.; Skarda, J. R.

    1987-01-01

    NASA's Airborne Doppler Lidar System has been used to obtain a detailed 'instantaneous' mapping of horizontal spatial wind fields at 600-800 m elevations on the east side of the San Gorgonio Pass in California, in the form of checkerboard-fashion horizontal wind vectors spaced at 300 m intervals along and normal to the flight path. Spatial autocorrelations for the lateral and longitudinal components are ensemble-averaged, and integral turbulent length scales are computed for the wind fields' longitudinal and lateral directions. The flow in the region studied does not appear to be isotropic.

  13. Microstructural studies on Alloy 693

    Energy Technology Data Exchange (ETDEWEB)

    Halder, R.; Dutta, R.S. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sengupta, P., E-mail: praneshsengupta@gmail.com [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Samajdar, I. [Dept. of Metall. Engg. and Mater. Sci., Indian Institute of Technology Bombay, Mumbai 400 072 (India); Dey, G.K. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2014-10-15

    Superalloy 693, is a newly identified ‘high-temperature corrosion resistant alloy’. Present study focuses on microstructure and mechanical properties of the alloy prepared by double ‘vacuum melting’ route. In general, the alloy contains ordered Ni{sub 3}Al precipitates distributed within austenitic matrix. M{sub 6}C primary carbide, M{sub 23}C{sub 6} type secondary carbide and NbC particles are also found to be present. Heat treatment of the alloy at 1373 K for 30 min followed by water quenching (WQ) brings about a microstructure that is free from secondary carbides and Ni{sub 3}Al type precipitates but contains primary carbides. Tensile property of Alloy 693 materials was measured with as received and solution annealed (1323 K, 60 min, WQ) and (1373 K, 30 min, WQ) conditions. Yield strength, ultimate tensile strength (UTS) and hardness of the alloy are found to drop with annealing. It is noted that in annealed condition, considerable cold working of the alloy can be performed.

  14. Fatigue and Creep Crack Propagation behaviour of Alloy 617 in the Annealed and Aged Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Julian K. Benz; Richard N. Wright

    2013-10-01

    The crack propagation behaviour of Alloy 617 was studied under various conditions. Elevated temperature fatigue and creep-fatigue crack growth experiments were conducted at 650 and 800 degrees C under constant stress intensity (triangle K) conditions and triangular or trapezoidal waveforms at various frequencies on as-received, aged, and carburized material. Environmental conditions included both laboratory air and characteristic VHTR impure helium. As-received Alloy 617 displayed an increase in the crack growth rate (da/dN) as the frequency was decreased in air which indicated a time-dependent contribution component in fatigue crack propagation. Material aged at 650°C did not display any influence on the fatigue crack growth rates nor the increasing trend of crack growth rate with decreasing frequency even though significant microstructural evolution, including y’ (Ni3Al) after short times, occurred during aging. In contrast, carburized Alloy 617 showed an increase in crack growth rates at all frequencies tested compared to the material in the standard annealed condition. Crack growth studies under quasi-constant K (i.e. creep) conditions were also completed at 650 degrees C and a stress intensity of K = 40 MPa9 (square root)m. The results indicate that crack growth is primarily intergranular and increased creep crack growth rates exist in the impure helium environment when compared to the results in laboratory air. Furthermore, the propagation rates (da/dt) continually increased for the duration of the creep crack growth either due to material aging or evolution of a crack tip creep zone. Finally, fatigue crack propagation tests at 800 degrees C on annealed Alloy 617 indicated that crack propagation rates were higher in air than impure helium at the largest frequencies and lowest stress intensities. The rates in helium, however, eventually surpass the rates in air as the frequency is reduced and the stress intensity is decreased which was not observed at 650

  15. Atomic Structure of Au−Pd Bimetallic Alloyed Nanoparticles

    KAUST Repository

    Ding, Yong

    2010-09-08

    Using a two-step seed-mediated growth method, we synthesized bimetallic nanoparticles (NPs) having a gold octahedron core and a palladium epitaxial shell with controlled Pd-shell thickness. The mismatch-release mechanism between the Au core and Pd shell of the NPs was systematically investigated by high-resolution transmission electron microscopy. In the NPs coated with a single atomic layer of Pd, the strain between the surface Pd layer and the Au core is released by Shockley partial dislocations (SPDs) accompanied by the formation of stacking faults. For NPs coated with more Pd (>2 nm), the stacking faults still exist, but no SPDs are found. This may be due to the diffusion of Au atoms into the Pd shell layers to eliminate the SPDs. At the same time, a long-range ordered L11 AuPd alloy phase has been identified in the interface area, supporting the assumption of the diffusion of Au into Pd to release the interface mismatch. With increasing numbers of Pd shell layers, the shape of the Au-Pd NP changes, step by step, from truncated-octahedral to cubic. After the bimetallic NPs were annealed at 523 K for 10 min, the SPDs at the surface of the NPs coated with a single atomic layer of Pd disappeared due to diffusion of the Au atoms into the surface layer, while the stacking faults and the L11 Au-Pd alloyed structure remained. When the annealing temperature was increased to 800 K, electron diffraction patterns and diffraction contrast images revealed that the NPs became a uniform Au-Pd alloy, and most of the stacking faults disappeared as a result of the annealing. Even so, some clues still support the existence of the L11 phase, which suggests that the L11 phase is a stable, long-range ordered structure in Au-Pd bimetallic NPs. © 2010 American Chemical Society.

  16. High-temperature Hydrogen Permeation in Nickel Alloys

    Energy Technology Data Exchange (ETDEWEB)

    P. Calderoni; M. Ebner; R. Pawelko

    2010-10-01

    In gas cooled Very High Temperature Reactor concepts, tritium is produced as a tertiary fission product and by activation of graphite core contaminants, such as lithium; of the helium isotope, He-3, that is naturally present in the He gas coolant; and the boron in the B4C burnable poison. Because of its high mobility at the reactor outlet temperatures, tritium poses a risk of permeating through the walls of the intermediate heat exchanger (IHX) or steam generator (SG) systems, potentially contaminating the environment and in particular the hydrogen product when the reactor heat is utilized in connection with a hydrogen generation plant. An experiment to measure tritium permeation in structural materials at temperatures up to 1000 C has been constructed at the Idaho National Laboratory Safety and Tritium Applied Research (STAR) facility within the Next Generation Nuclear Plant program. The design is based on two counter flowing helium loops to represent heat exchanger conditions and was optimized to allow control of the materials surface condition and the investigation of the effects of thermal fatigue. In the ongoing campaign three nickel alloys are being considered because of their high-temperature creep properties, alloy 617, 800H and 230. This paper introduces the general issues related to tritium in the on-going assessment of gas cooled VHTR systems fission product transport and outlines the planned research activities in this area; outlines the features and capabilities of the experimental facility being operated at INL; presents and discusses the initial results of hydrogen permeability measurements in two of the selected alloys and compares them with the available database from previous studies.

  17. Nuclear magnetic resonance-based metabonomics features before and after 800 meters race%基于核磁共振的800 m跑训练前后尿液代谢组学特征

    Institute of Scientific and Technical Information of China (English)

    李植; 马海峰; 吴瑛; 贾银浩

    2015-01-01

    背景:目前研究发现800 m跑的代谢特征不是十分明晰,为800 m的运动训练造成了很大的阻碍。目的:了解800 m跑项目的物质和能量代谢特征,提高800 m跑训练的科学化水平,验证基于核磁共振的尿液代谢组学技术在运动训练监测方面的可行性。方法:对某高校运动训练专业7名中跑2级运动员进行一次极限强度800 m跑,结合人体代谢数据库(HMDB)等数据库,对运动前、后的尿液进行代谢组学相关分析。结果与结论:OPLS-DA模型显示运动前和运动后样本的代谢模式呈现簇类分布。造成这一变化的特征性代谢物主要有亮氨酸、乳酸、肌酐、琥珀酸、次黄嘌呤、腺苷等代谢物。通过分析可以推断出800 m跑是以糖酵解供能为主、磷酸原供能和有氧氧化供能共同参与的运动项目,800 m跑后运动员氨基酸代谢、甲烷代谢等代谢过程较为旺盛,而且在800 m跑的过程中会出现一定程度的氧化应激。结果说明基于核磁共振的尿液代谢组学技术有无创性、灵敏度高、样品需求量少、处理简单等优势。%BACKGROUND:Metabolic characteristics of the 800 meters race is not very clear, which creates a lot of obstacles for the exercise training of 800 meters race. OBJECTIVE: To investigate the characteristics of material and energy metabolism of 800 meters race, to improve the scientific training of the 800 meters race and to verify the feasibility of nuclear magnetic resonance-based urine metabonomics in sports training monitoring. METHODS: Seven middle distance athletes were subject to an 800 meters race at ultimate intensity, and their urine metabonomics analysis was conducted in combination with the Human Metabolism Database and other databases before and after exercise. RESULTS AND CONCLUSION:OPLS-DA model showed that the metabolic samples before and after movement presented the cluster-like distribution. The change was mainly

  18. High-temperature alloys and thermal spray coatings for energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Al-Taie, I.; Brigham, R.J.; Lafreniere, Y. [CANMET, Ottawa, Ontario (Canada). Metals Technology Lab.

    1995-12-31

    Materials continue to be of primary concern as the potential limiting factor for the implementation of coal gasification technology in Canada. Superalloys and thermal spray coatings for syngas coolers represent one class of materials where a knowledge of general trends in oxidation/sulphidation and erosion resistance for a range of chemical compositions is thought to be essential for reliable operation of such technology. Alloy 800H, 304, 310, T91, Monit and Sanicro 28 along with four types of coatings (Al{sub 2}O{sub 3}, Cr{sub 2}O{sub 3}, Al{sub 2}O{sub 3}/Ni3Al and CoCrAlYNi) applied on each one of the above alloys have been subjected to a series of exposures (6 {times} 250h cycles) in two different gas mixtures containing CO, H{sub 2}, H{sub 2}S, H{sub 2}O at 600 C. The kinetics and mechanisms of corrosion and erosion of these alloys have been investigated using Scanning Electron Microscopy and surface analytical techniques. Thermal spray coatings of ceramic and composite materials were found to be problematic on austenitic alloys because of spallation. Ceramic, composite and metallic coatings adhered well to the ferritic alloy. Nickel aluminide in combination with aluminum oxide as a composite did not display the expected high degree of corrosion resistance. High temperature erosion rates were found to be low on the bare superalloys and to be decreased by highly alloyed metallic coatings such as CoCrAlYNi, FeCrAlYMo and NiCrAlYCo. Ceramic and composite coatings were ineffective in reducing erosion rates because of spallation and reactivity in the simulated gasification environment.

  19. Nickel based alloys compatibility with fuel salts for molten salt reactor with thorium and uranium support

    International Nuclear Information System (INIS)

    R and D on molten salt reactors (MSR) in Europe are concentrated now on fast/intermediate spectrum concepts which were recognised as long-term alternative to solid fuelled fast reactors due to their attractive features: strong negative feedback coefficients, easy in-service inspection, and simplified fuel cycle. For high-temperature MSR corrosion of the metallic container alloy in primary circuit is the primary concern. Key problem receiving current attention include surface fissures in Ni-based alloys probably arising from fission product tellurium attack. This paper summarises results of corrosion tests conducted recently to study effect of oxidation state in selected fuel salts on tellurium attack and to develop means of controlling tellurium cracking in the special Ni - based alloys recently developed for large power units: molten salt actinide recycler and transmuter (MOSART) and molten salt fast reactor (MSFR). Tellurium corrosion of Ni-based alloys was tested in the temperature range from 730 deg. C up to 800 deg. C in stressed and unloaded conditions with fuel LiF-BeF2-UF4 and LiF-BeF2-ThF4-UF4 salt mixtures at different [U(IV)]/[U(III)] ratios from 0.7 up to 500. Following Russian and French Ni-based alloys (in mass%): HN80M-VI (Mo-12, Cr-7.6, Nb-1.5), HN80MTY (Mo-13, Cr-6.8, Al-1.1, Ti-0.9), HN80MTW (Mo-9.4, Cr-7.0, Ti-1.7, W-5.5) and EM-721 (W-25.2, Cr-5.7, Ti-0.17) were used for the study in the corrosion facility. The HN80MTY alloy has shown the best resistance against Te cracking and after test mechanical properties. (authors)

  20. Environmentally induced fracture of nickel alloys: a comparison of hydrogen and mercury embrittlement with respect to temperature

    International Nuclear Information System (INIS)

    Previous studies have compared electrolytic hydrogen embrittlement (HE) and liquid metal embrittlement (LME) by mercury for numerous nickel alloys. All alloys tested exhibited embrittlement to some degree with HE and LME having similar fractographies. This study examines the effect of temperature on He and LME of Monel 400 over the range -30 and 800C. Slow strain rate tensile tests were conducted at two strain rates, 1.6 x 10-5s-1 and 1.6 x 10-3s-1, and two grain sizes, 35 μm and 250 μm. Behavior of Monel 400 is compared with previously studied nickel alloys. Results showed that intergranular, tranogranular, and microvoid-coalescence fractures can be obtained in both hydrogen and mercury. Fracture mode is governed by strain at fracture. Embrittlement ceases below -200 in both environment, believed due to lack of mobility of adsorbed hydrogen and lack of wetting by mercury. LME is more severe than HE because hydrogen blunts cracks by promoting plasticity. HE ceases at about 800C because excess plasticity promotes crack blunting and inhibits initiation. LME fractures remain brittle to 800C. An incubation period is normally needed for adsorption of the embrittler or for penetration of the crack through the plane stress surface zone. Otherwise ductile failures in mercury often exhibit longitudinal splitting, believed to be due to the combination of high normal stress, low shear stress, and a clean surface. The existence of a temperature window for LME can be explained on the basis of strain activated localized wetting. Results of this study are consistent with a decohesion mechanism producing intergranular fracture; competing with an enhanced dislocation nucleation mechanism producing transgranular fracture. Monel 400 exhibited the range of features observed for other nickel base alloys at appropriate conditions of temperature, strain rate, and grain size

  1. Structural evolutions of the mechanically alloyed Al70Cu20Fe10 powders

    Indian Academy of Sciences (India)

    Musa Göğebakan; Bariş Avar

    2011-10-01

    Elemental mixtures of Al, Cu, Fe powders with the nominal composition of Al70Cu20Fe10 were mechanically alloyed in a planetary ball mill for 80 h. Subsequent annealing of the as-milled powders were performed at 600–800°C temperature range for 4 h. Structural characteristics of the mechanically alloyed Al70Cu20Fe10 powders with the milling time and the heat treatment were investigated by X-ray diffraction (XRD), differential scanning calorimeter (DSC) and differential thermal analysis (DTA). Mechanical alloying of the Al70Cu20Fe10 did not result in the formation of icosahedral quasicrystalline phase (i-phase) and a long time milling resulted in the formation of -Al(Cu,Fe) solid solution phase (-phase). The i-phase was observed only for short-time milled powders after heat treatment above 600°C. The -phase was one of the major phases in the Al70Cu20Fe10 alloy. The w-Al7Cu2Fe1 phase (w-phase) was obtained only after heat treatment of the short-time milled and unmilled samples. The present investigation indicated that a suitable technique to obtain a large amount of quasicrystalline powders is to use a combination of short-time milling and subsequent annealing.

  2. Effect of heat treatment on structural changes in metastable AlSi10mg alloy

    Directory of Open Access Journals (Sweden)

    Jordović B.

    2014-01-01

    Full Text Available This paper presents a study on structural changes occurring in a rapidly quenched metastable AlSi10Mg alloy during heating cycles within the temperature range from room temperature to 800 K. Measurement of electrical resistivity of a ribbon showed that structural stabilization takes place at temperatures ranging from 450 K to 650 K. The isotherms of the electrical resistivity measured at temperatures 473 K, 483 K and 498 K revealed two stages of structural stabilization i.e. a kinetic process and diffusion process. Measurement of the thermoelectromotive force of the thermocouple made from the investigated alloy and a copper conductor by a mechanical joining was used to determine relative changes in the electron density of states of the quenched sample after successive heat treatments. The same alloy sample was subjected to successive heat treatments at temperatures up to 503 K, 643 K, 683 K and 763 K. The change in the thermopower suggested that each heating was followed by an increase in free electron density in the alloy. Therefore, the abrupt decline in electrical resistivity was induced by an increase in both the mean free electron path and free electron density during the thermal stabilization of the structure. [Projekat Ministarstva nauke Republike Srbije, br. OI 172057: Controlled synthesis, structure and properties of multifunctional materials

  3. CoPt alloy films on SiO{sub 2} nanoparticle arrays

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, Denys; Schatz, Guenter [University of Konstanz (Germany). Department of Physics; Bermudez, Esteban; Schmidt, Oliver G. [IFW, Dresden (Germany); Brombacher, Christoph; Albrecht, Manfred [Chemnitz University of Technology (Germany). Institute of Physics; Liscio, Fabiola; Maret, Mireille [ENSEEG, Saint Martin d' Heres (France)

    2008-07-01

    Combining self-assembled SiO{sub 2} nanoparticle arrays with magnetic film deposited onto the particles, enables an elegant possibility to create magnetic nanostructure arrays with defined magnetic properties. In this regard, materials such as CoPt alloy are of particular interest due to their large magnetic anisotropy required for thermal stability in the high density magnetic recording applications. In order to induce high perpendicular magnetic anisotropy in CoPt alloys, the L1{sub 0} phase with (001) texturing is required. For this purpose, a 10 nm thick MgO(001) seed layer was introduced. Results on planar amorphous SiO{sub 2} substrates reveal an uniaxial out-of-plane magnetic anisotropy and saturation magnetization for the CoPt alloy grown at 450 C of about 5x10{sup 5} J/m{sup 3} and 800 kA/m. These properties were transfered to CoPt alloy deposited onto arrays of SiO{sub 2} particles with diameters down to 50 nm. The formed CoPt nanocaps are in a magnetic single domain state with a large out-of-plane coercivity, which increases with decreasing particle size. In this presentation, the structural and magnetic properties are discussed and compared to the planar film.

  4. Kinetics and Mechanism of Nanostructures in Oxidation of Si1-xGex Alloys

    Institute of Scientific and Technical Information of China (English)

    黄伟其; 蔡绍洪

    2002-01-01

    We investigate the oxidation behaviour of Si1-xGex alloys (x = 0.05, 0.15, and 0.25). The oxidation of SiGe flms with different compositions was carried out in O2 (dry) atmosphere at 800, 900 and 1000°C, respectively,for various lengths of time. The thickness and property of the nanoparticle and nanolayer in oxide films and germanium segregation in oxidation of SiGe alloys are measured by using a high precision ellipsometer. The results are in good agreement with the Rutherford backscattering spectrometry, profile dektak instrument and high-resolution scanning transmission electron microscopy. We found that the Ge content in the oxide layer increases with the Ge content in SiGe alloys, and that the Ge content in the oxide film decreases with the increasing oxidation temperature and time. Rejection of Ge results in piling up of Ge at the interface between the growing SiO2 and the remaining SiGe, which forms a nanometre Ge-rich layer. Substantial interdiffusion of Si and Ge takes place in the remaining SiGe, which leads to the complicated distribution of Ge segregation. We find a nanometre cap layer over the oxide film after fast oxidation, in which there are many Ge nanoparticles.We analyse the kinetics and mechanism of the nanostructure of the oxide and Ge segregation in oxidation of Si1- x Gex alloys.

  5. Dynamic mechanical analyze of superelastic CuMnAl shape memory alloy

    Science.gov (United States)

    (Dragoș Ursanu, A. I.; Stanciu, S.; Pricop, B.; Săndulache, F.; Cimpoeșu, N.

    2016-08-01

    A new shape memory alloy was obtain from high purity Cu, Mn and Al elements using a induce furnace. The intelligent material present negative transformation temperatures and an austenite like state at room temperature. The austenite state of CuMnAl shape memory alloy present superelasticity property. Five kilograms ingot was obtain of Cu10Mn10Al alloy. From the base material (melted state) were cut samples with 6 mm thickness using a mechanical saw. After an homogenization heat treatment the samples were hot rolled through four passes with a reduction coefficient of 20%. Experimental lamellas were obtained with 1.5 mm thickness and 90x10 mm length and width. After the hot rolled treatment the materials were heat treated at 800°C for 20 minutes and chilled in water. Four samples, one just laminated and three heat treated by aging, were analyzed with a Netzsch DMA equipment to establish the elastic modulus and the internal friction values of the materials. Metallic materials microstructure was analyzed using a scanning electron microscope Vega Tescan LMH II type. After the aging heat treatment a decrease of internal friction is observed on the entire analyze range which is assigned to formation of Al-based precipitates that block the internal movement of the alloy characteristic phases.

  6. Reduction of nitric oxide with carbon monoxide on the Al-Mo(110) surface alloy

    Science.gov (United States)

    Grigorkina, G. S.; Tvauri, I. V.; Kaloeva, A. G.; Burdzieva, O. G.; Sekiba, D.; Ogura, S.; Fukutani, K.; Magkoev, T. T.

    2016-05-01

    Coadsorption and reaction of carbon monoxide (CO) and nitric oxide (NO) on Al-Mo(110) surface alloy have been studied by means of Auger electron, reflection-absorption infrared and temperature programmed desorption spectroscopies (AES, RAIRS, TPD), low energy electron diffraction (LEED) and work function measurements. The Al-Mo(110) surface alloy was obtained by thermal annealing at 800 K of aluminum film deposited on Mo(110) held at room temperature. Upon annealing Al penetrates the surface, most likely forming stoichiometric hexagonal surface monolayer of the compound Al2Mo. The NO and CO adsorb molecularly on this alloy surface at 200 K, unlike totally dissociative adsorption on bare Mo(110) and Al(111) film. Adsorption of CO on NO precovered Al-Mo(110) substrate dramatically affects the state of NO molecules, most probably displacing them to higher-coordinated sites with their simultaneous tilting to the surface plane. Heating to about room temperature (320 K) causes reduction of nitric oxide with carbon monoxide, yielding CO2, and substrate nitridation. This behavior can be associated with the surface reconstruction providing additional Al/Mo interface reaction sites and change of the d-band upon alloying.

  7. Atom probe study of Cu-segregation in thermal aging of binary Fe-Cu alloys

    International Nuclear Information System (INIS)

    Fe-Cu binary alloy is commonly used as a prototype model alloy for Pressurized Water Reactor (PWR) pressure vessel steels, especially for the study of radiation damage. This is because of the fact that Cu is one of the main solutes, segregation of which is known to cause major embrittlement in reactor pressure vessel (RPV) steels under nuclear radiation. Interestingly, similar solute segregation is often noticed in case of radiation-free long-term thermal aging experiments as well. Therefore, thermal aging experiment which is considerably simpler can be effectively utilized to study the solute segregation behaviour and emulate radiation-induced damage. With this objective, a series of binary Fe-Cu alloys with Cu concentration varying from 0.1 at. % - 1.4 at. % were prepared by vacuum arc melting. They were subsequently cold-rolled, followed by homogenization at 800 C and water quenching. The homogenized samples were then aged at 500 C for the following different durations: 1, 3, 5, 8, 25, 50 and 100 h. 3DAP is an indispensable tool to study solute segregation at this length scale, and the current study will present the results of a detailed 3DAP investigation of the evolution of the thermal damage in these binary prototype alloys. (author)

  8. Ni–Mo–Co ternary alloy as a replacement for hard chrome

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Meenu, E-mail: meenu_srivas@yahoo.co.uk; Anandan, C.; Grips, V.K. William

    2013-11-15

    Hard chrome is the most extensively used electroplated coating in the aerospace and automotive industries due to its attractive properties such as high hardness and excellent wear resistance. However, due to the health risks associated with the use of hexavalent chromium baths during electroplating, there is a need to identify an alternative to this coating. In this study a nickel–molybdenum alloy with cobalt as the alloying element has been developed. The coating was characterized for its micro hardness, wear resistance, coefficient of friction and corrosion resistance. The coating was also subjected to heat treatment at temperatures in the range of 200°–600 °C. It was observed that the micro hardness of Ni–Mo–Co (730 KHN) alloy coating under optimized conditions is apparently quiet similar to that of the most probable substitute Co–P (745 VHN) and hard chrome (800 VHN) coatings. The tribological properties like the wear rate and coefficient of friction of the 400 °C heat treated Ni–Mo–Co coating were noticed to be better compared to hard chrome coating. The electrochemical impedance and polarization studies showed that the corrosion resistance of heat treated Ni–Mo–Co alloy was better than as-deposited Ni–Mo–Co and Ni–Mo coating.

  9. Fragility and glass forming ability of Al-Ni-Ce alloy melts

    Institute of Scientific and Technical Information of China (English)

    赵岩; 边秀房; 孙民华; 张均艳

    2004-01-01

    The fragility of Al-Ni-Ce alloy melts with three kinds of different compositions, Al85Ni10Ce5,Al85Ni8Ce7, Al85Ni5Ce10(mole fraction, %), was studied using oscillating-vessel viscometer and differential scanning calorimetry. Their fragility parameters obtained from experiments and theoretic calculation are:238,228 and 335 respectively. The results indicate that these three kinds of Al-Ni-Ce alloy melts are very fragile liquids, which kinetically show strong non-Arrhenius behaviour in the Angell plot, so they have poor glass forming ability (GFA).The alloy melt Al85Ni5Ce10 has the largest fragility parameter among the three alloy melts. In the preparation of rapidly quenched amorphous ribbons, Al85Ni10Ce5 and Al85Ni8Ce7 can gain amorphous ribbons when the rotate speed of the roller reaches 800 r/min, while for Al85Ni5Ce10 it must exceed 1 000 r/min.

  10. Effect of Thermal Aging on the Corrosion Behavior of Wrought and Welded Alloy 22

    International Nuclear Information System (INIS)

    Alloy 22 (UNS N06022) is a candidate material for the external wall of the high level nuclear waste containers for the potential repository site at Yucca Mountain. In the mill-annealed (MA) condition, Alloy 22 is a single face centered cubic phase. When exposed to temperatures on the order of 600 C and above for times higher than 1 h, this alloy may develop secondary phases that are brittle and offer a lower corrosion resistance than the MA condition. The objective of this work was to age Alloy 22 at temperatures between 482 C and 800 C for times between 0.25 h and 3,000 h and to study the corrosion performance of the resulting material. Aging was carried out using wrought specimens as well as gas tungsten arc welded (GTAW) specimens. The corrosion performance was characterized using standard immersion tests in aggressive acidic solutions and electrochemical tests in multi-component solutions. Results show that, in general, in aggressive acidic solutions the corrosion rate increased as the aging temperature and aging time increased. However, in multi ionic environments that could be relevant to the potential Yucca Mountain site, the corrosion rate of aged material was the same as the corrosion rate of the MA material

  11. A Brief Analysis of Relation Between 800 - meter Special Training and 400 - meter Training%浅析800m跑专项训练及与400m的训练关系

    Institute of Scientific and Technical Information of China (English)

    周丰昌

    2005-01-01

    在分析有关田径训练资料和科研结果的基础上,就径赛项目中400和800m的项目特点、两者间的训练关系,如何以800m为主项安排训练等,提出一些训练参考性意见.

  12. Corrosion and mechanical property at high temperature of nickel based alloy for VHTR

    International Nuclear Information System (INIS)

    Using a very high temperature reactor (VHTR), it is conceptually and practically possible to generate highly efficient electricity and produce massive hydrogen among generation IV nuclear power plants. The structural material for an intermediate heat exchanger (IHX) is exposed to high temperature of up to 950 .deg. C. In this harsh environment, nickel-based alloys such as Alloy 617 and Haynes 230 are considered as promising candidate materials for IHX material owing to their excellent creep resistances at high temperature. However, high-temperature degradation cannot be avoided even for nickel-based alloy. Helium which inevitably includes impurities such as H2, CH4, H2O and CO is used as a coolant in a VHTR. Material degradation is aggravated by corrosion under an impure helium environment, which is one of the main obstacles to overcome for the application and successful long-term operation of a VHTR. A review of the thermodynamics indicates which reactions are available on the surface of the materials among oxidation, carburization and decarburization, but it does not give US the kinetic preference. This kinetic preference can induce localized corrosion, kinetic irreversibility and long-term material instability leading to material degradation. In addition to a long-term corrosion test under a VHTR coolant environment, the development of new alloys superior to commercial nickel-based alloy also give way to the successful establishment of a VHTR. Commercial nickel-based wrought alloy is strengthened by a solid solution and precipitation hardening mechanism in a wide temperature range of 500 to 900 .deg. C. The γ' significantly contributes to the strengthening by locking dislocation motion by an antiphase boundary at an intermediate temperature range of 700 to 800 .deg. C, but is no longer stable above this temperature range. However, the material for an IHX needs to fulfill the mechanical property requirements in a narrow and very high temperature range of 850 to

  13. Elastic scattering of polarized protons on deuterium at 800 MeV

    International Nuclear Information System (INIS)

    A specific set of spin transfer coefficients has been measured for proton-deuteron elastic scattering at 800 MeV using an unpolarized liquid deuterium target. The experiment was done using the High Resolution Spectrometer (HRS) at the Los Alamos Meson Physics Facility (LAMPF) with a polarized proton beam. The scattered proton spin direction was determined using the Focal Plane Polarimeter (FPP) of the HRS, which employs a carbon analyzer. Some of the spin dependent parameters measured in this experiment are of considerable interest because they provide selective information about the nucleon-nucleon (NN) amplitude. Since the deuteron is the simplest bound nucleus, pd elastic scattering is particularly well suited for testing multiple scattering theories. These measurements will also be used to eventually determine the full pd collision matrix, which contains all possible information about the scattering process. In addition, the experimental setup is described for a polarized proton-polarized deuterium target spin transfer experiment also done at the HRS at 800 MeV incident proton energy. 71 references

  14. Optimal Pacing for Running 400 m and 800 m Track Races

    CERN Document Server

    Reardon, James C

    2012-01-01

    Physicists seeking to understand complex biological systems often find it rewarding to create simple "toy models" that reproduce system behavior. Here a toy model is used to understand a puzzling phenomenon from the sport of track and field. Races are almost always won, and records set, in 400 m and 800 m running events by people who run the first half of the race faster than the second half, which is not true of shorter races, nor of longer. There is general agreement that performance in the 400 m and 800 m is limited somehow by the amount of anaerobic metabolism that can be tolerated in the working muscles in the legs. A toy model of anaerobic metabolism is presented, from which an optimal pacing strategy is analytically calculated via the Euler-Lagrange equation. This optimal strategy is then modified to account for the fact that the runner starts the race from rest; this modification is shown to result in the best possible outcome by use of an elementary variational technique that supplements what is foun...

  15. Isothermal section of Nd-Mn-As phase diagram at 800 C

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Zheng Fei; Hu, Kai; Cheng, Gang; Lin, Rui San; Hong, Liang Jie [Guilin Univ. of Electronic Technology, School of Material Science and Engineering, Guangxi (China); Xu, Cheng Fu [Guilin Univ. of Electronic Technology, School of Material Science and Engineering, Guangxi (China); Guilin Univ. of Aerospace Technology, Dept. of Mechanical Engineering, Guangxi (China)

    2015-09-15

    The isothermal section of the Nd-Mn-As ternary system at 800 C has been constructed in this work by using X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy techniques. This isothermal section consists of 11 single-phase regions, 19 two-phase regions and 9 three-phase regions. The maximum solubility of As in (Mn) is about 2.602 at.% As and that of Mn in Mn{sub 3}As and NdAs is below 1 at.% Mn. The highest solid solubility of Nd in MnAs is less than 1.25 at.% Nd. The decomposition temperature of NdAs{sub 2} → NdAs + As is about 668 C. The phase Nd{sub 3}As could be slowly composed by peritectic reaction L + NdAs → Nd{sub 3}As at higher temperature. The phase Mn3As still exists under this experimental condition. No ternary compound was found to exist in this section at 800 C.

  16. K0* (800) as a companion pole of K0* (1430)

    Science.gov (United States)

    Wolkanowski, T.; Sołtysiak, M.; Giacosa, F.

    2016-08-01

    We study the light scalar sector up to 1.8 GeV by using a quantum field theoretical approach which includes a single kaonic state in a Lagrangian with both derivative and non-derivative interactions. By performing a fit to πK phase shift data in the I = 1 / 2, J = 0 channel, we show that K0* (800) (or κ) emerges as a dynamically generated companion pole of K0* (1430). This is a result of investigating quantum fluctuations with one kaon and one pion circulating in the loops dressing K0* (1430). We determine the position of the poles on the complex plane in the context of our approach: for K0* (1430) we get (1.413 ± 0.002) - i (0.127 ± 0.003) (in GeV), while for κ we get (0.746 ± 0.019) - i (0.262 ± 0.014) (in GeV). The model-dependence of these results and related uncertainties are discussed in the paper. A large-Nc study confirms that K0* (1430) is predominantly a quarkonium and that K0* (800) is a molecular-like dynamically generated state.

  17. Analysis of emergency situations caused by BN-800 primary circuit pressure pipe depressurization

    International Nuclear Information System (INIS)

    The results of the analysis of emergency situations caused by BN-800 reactor pressure pipe depressurization are presented in the report. Russian BN-600 and BN-800 designs have characteristic features, which influence upon the processes run at the primary circuit pressure pipe depressurization: - individual suction of primary circuit MCP; - safeguard housings at the diagrid and pressure pipes; - detection system of pressure pipes uptightness; - safeguard devices in the support belt. Analysis of emergency situations and their consequences from the point of view of their effect upon the core and support belt is presented in the report. The following events are taken as initial ones: - leak of 0.5 mm equivalent diameter in the pressure pipe being a result of initial defect in the pipeline weld penetration thorough the whole wall thickness; - postulated ruptures of pressure pipes DN5 5, DN 120, DN200; - instantaneous guillotine rupture of one of six pressure pipes DN600 with the pipelines ends moving apart (outflow from two DN600 sections). Analysis of all the aforementioned events shows, that reactor safety is provided at all situations, including instantaneous guillotine rupture of one pipeline DN600 (sodium boiling and fuel melting are absent). (author)

  18. Fatigue crack growth behavior of the simulated HAZ of 800 MPa grade high-performance steel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sanghoon [Division of Materials Science and Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kang, Donghwan; Kim, Tae-Won [School of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Lee, Jongkwan [Research Institute of Industrial Science and Technology, 75-9, Youngcheon, Dongtan, Hwaseong, Gyeonggi-do 445-813 (Korea, Republic of); Lee, Changhee, E-mail: chlee@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

    2011-03-15

    Research highlights: {yields} Fatigue crack resistances of HSB800 base steel and HAZs: Base steel > FGHAZ > CGHAZ > ICCGHAZ. {yields} In the case of ICCGHAZ, fatigue cracks are rapidly initiated and propagated through massive M-A constituents. {yields} Fatigue crack growth rate of CGHAZ was faster than that of FGHAZ, mainly due to the coarsened prior austenite grain and martensite packet. - Abstract: The present study focuses on the fatigue properties in the weld heat-affected zone (HAZ) of 800 MPa grade high-performance steel, which is commonly used in bridges and buildings. Single- and multi-pass HAZs were simulated by the Gleeble system. Fatigue properties were estimated using a crack propagation test under a 0.3 stress ratio and 0.1 load frequencies. The microstructures and fracture surfaces were analyzed by optical microscopy, scanning electron microscopy, and transmission electron microscopy. The results of the crack propagation test showed that the fatigue crack growth rate of coarse-grained HAZ (CGHAZ) was faster than fine-grained HAZ (FGHAZ), although both regions have identical fully martensite microstructures, because FGHAZ has smaller prior austenite grain and martensite packet sizes, which can act as effective barriers to crack propagation. The fatigue crack growth rate of intercritically reheated CGHAZ (ICCGHAZ) was the fastest among local zones in the HAZ, due to rapid crack initiation and propagation via the massive martensite-austenite (M-A) constituent.

  19. Fatigue crack growth behavior of the simulated HAZ of 800 MPa grade high-performance steel

    International Nuclear Information System (INIS)

    Research highlights: → Fatigue crack resistances of HSB800 base steel and HAZs: Base steel > FGHAZ > CGHAZ > ICCGHAZ. → In the case of ICCGHAZ, fatigue cracks are rapidly initiated and propagated through massive M-A constituents. → Fatigue crack growth rate of CGHAZ was faster than that of FGHAZ, mainly due to the coarsened prior austenite grain and martensite packet. - Abstract: The present study focuses on the fatigue properties in the weld heat-affected zone (HAZ) of 800 MPa grade high-performance steel, which is commonly used in bridges and buildings. Single- and multi-pass HAZs were simulated by the Gleeble system. Fatigue properties were estimated using a crack propagation test under a 0.3 stress ratio and 0.1 load frequencies. The microstructures and fracture surfaces were analyzed by optical microscopy, scanning electron microscopy, and transmission electron microscopy. The results of the crack propagation test showed that the fatigue crack growth rate of coarse-grained HAZ (CGHAZ) was faster than fine-grained HAZ (FGHAZ), although both regions have identical fully martensite microstructures, because FGHAZ has smaller prior austenite grain and martensite packet sizes, which can act as effective barriers to crack propagation. The fatigue crack growth rate of intercritically reheated CGHAZ (ICCGHAZ) was the fastest among local zones in the HAZ, due to rapid crack initiation and propagation via the massive martensite-austenite (M-A) constituent.

  20. Election Districts and Precincts, Published in 2002, 1:9600 (1in=800ft) scale, Jefferson County Land Information Office.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Election Districts and Precincts dataset, published at 1:9600 (1in=800ft) scale, was produced all or in part from Published Reports/Deeds information as of...