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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. Alloy 800 SG tubing: current status and future challenges

    International Nuclear Information System (INIS)

    Alloy 800 has been used for steam generator (SG) tubing for more than 30 years, primarily in CANDU reactors and in reactors in Germany. The grade of Alloy 800 tubing used for this service has a controlled Ti/C ratio (≥12 for CANDU SGs), and this specification is sometimes termed Alloy 800 M or Alloy 800 NG . There have been very few corrosion-related flaws detected in this material in SG service, and, until recently, no incidences of cracking. There has been extensive R and D carried out on Alloy 800 tubing, both in Canada and elsewhere, under a variety of operating conditions, including shutdowns, which show that it has excellent resistance to corrosion-related degradation under specified and appropriate operating conditions. These R and D findings are reflected in the in-service experience. It has been shown from the R and D that Alloy 800 is susceptible to corrosion under acidic conditions, in particular those that can arise as a consequence of phosphate water treatment or sulphur-related contamination. In common with all SG tubing materials, Alloy 800 is susceptible to corrosion under layup conditions if the pH is low, as can occur when reduced sulphates may be present (polythionic acids). SG layup, and startup and shutdown transients, are probably the most vulnerable conditions for SG tubing when both oxidizing conditions and acid-forming impurities may be present (chloride and sulphate, for example). Most of this corrosion is expected to occur in crevices (such as the tube-to-tubesheet, TTS, and tube-to-support plate, TSP, crevices) or under deposits (including tubesheet sludge piles and thick freespan deposits). This has been the experience in SGs tubed with Alloy 600. A key input into the life cycle management of SGs is the probability of degradation occurring during the remaining, and any extended, life of the SG. For SGs with Alloy 800 tubing, the lack of corrosion-related degradation to date implies that assumptions need to be made about the

  4. Alloy 800 SG tubing: current status and future challenges

    Energy Technology Data Exchange (ETDEWEB)

    Tapping, R.L.; Lu, Y.C. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Pandey, M.D. [Univ. of Waterloo, Inst. for Risk Research, Waterloo, Ontario (Canada)

    2007-07-01

    Alloy 800 has been used for steam generator (SG) tubing for more than 30 years, primarily in CANDU reactors and in reactors in Germany. The grade of Alloy 800 tubing used for this service has a controlled Ti/C ratio ({>=}12 for CANDU SGs), and this specification is sometimes termed Alloy 800 M or Alloy 800 NG . There have been very few corrosion-related flaws detected in this material in SG service, and, until recently, no incidences of cracking. There has been extensive R and D carried out on Alloy 800 tubing, both in Canada and elsewhere, under a variety of operating conditions, including shutdowns, which show that it has excellent resistance to corrosion-related degradation under specified and appropriate operating conditions. These R and D findings are reflected in the in-service experience. It has been shown from the R and D that Alloy 800 is susceptible to corrosion under acidic conditions, in particular those that can arise as a consequence of phosphate water treatment or sulphur-related contamination. In common with all SG tubing materials, Alloy 800 is susceptible to corrosion under layup conditions if the pH is low, as can occur when reduced sulphates may be present (polythionic acids). SG layup, and startup and shutdown transients, are probably the most vulnerable conditions for SG tubing when both oxidizing conditions and acid-forming impurities may be present (chloride and sulphate, for example). Most of this corrosion is expected to occur in crevices (such as the tube-to-tubesheet, TTS, and tube-to-support plate, TSP, crevices) or under deposits (including tubesheet sludge piles and thick freespan deposits). This has been the experience in SGs tubed with Alloy 600. A key input into the life cycle management of SGs is the probability of degradation occurring during the remaining, and any extended, life of the SG. For SGs with Alloy 800 tubing, the lack of corrosion-related degradation to date implies that assumptions need to be made about the

  5. 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

  6. 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

  7. 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)

  8. 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

  9. 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.

  10. 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)

  11. 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)

  12. 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

  13. Optimization of INCOLOY alloy 800 mechanical properties for various power plant requirements

    International Nuclear Information System (INIS)

    The AMSE Boiler Code development of design stresses and their optimization for alloys 800 and 800H for conventional and nuclear power plants have coincided with many successful trial installations of these grades of alloy 800. These trial installations, along with laboratory tests, have shown that alloy 800H can be used for long times with a retention of good mechanical properties, including ductility. While gamma prime can be formed, it soon loses its detrimental effect on ductility in service. Sensitization of the alloy also occurs but it, too, has a decreasing effect on corrosion resistance with time in service, especially at elevated temperatures. The authors discuss all of these aspects and conclude that alloy 800 perhaps with low carbon control in the annealed (1800 to 1950degF)(982 to 1066degC) condition gives the optimum combination of properties to 1050degF(566degC) and alloy 800H (.05 to .10%C) solution annealed at 2100 to 2200degF (1149 to 1204degC) has optimum properties above 1050degF (566degC). The effects of aluminium and titanium and the benefit of keeping these within the ASTM limits of .15 to .60% are also stressed. (author)

  14. A comparison of the passive oxide films formed on CANDU steam generator tubing alloy 600 and alloy 800

    International Nuclear Information System (INIS)

    Alloy 600 (A600) steam generator (SG) tubing has been shown to be susceptible to stress corrosion cracking (SCC). Alloy 800 (A800) was developed as a replacement, though it has shown susceptibility to corrosion under certain conditions. The properties of the passive oxide films on both alloys were extensively analyzed to determine why the performance of A800 is superior to that of A600. Surface analysis to determine oxide composition was performed using X-ray photoelectron spectroscopy (XPS) and Auger Electron spectroscopy (AES). Electrochemical measurements were made using anodic polarization and electrochemical impedance spectroscopy (EIS). The oxide films on A600 and A800 were shown to have different electrochemical and compositional properties. (author)

  15. Effect of the structure on the low-cycle fatigue behaviour of alloy 800

    International Nuclear Information System (INIS)

    Alloy 800 (grade I) is used for making the steam generators of liquid metal fast breeder reactors. At working temperature (5250C) alloy 800 is strengthned by γ' (Ni3(Ti,Al)) precipitation which occurs during thermal aging. The mechanical properties of this alloy depend on the parameters which define the γ' precipitation and obviously on the structural characteristics due to the thermomechanical treatments which govern the manufacture of the product. For one cast of alloy 800 this work aims to analyse the influence, on low cycle fatigue behaviour at 5500C, of structural and microstructural variations originating either in different elaboration procedures or in γ' precipitation obtained by a thermal aging of 3000h at 5500C with or without a preceeding cold working of 10%

  16. 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

  17. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Berka, Jan, E-mail: Jan.Berka@cvrez.cz [Research Centre Rez Ltd., Hlavni 130, 25068 Husinec-Rez (Czech Republic); University of Chemistry and Technology Prague, Technicka 1905, 16628 Prague 6 (Czech Republic); Vilémová, Monika, E-mail: vilemova@ipp.cas.cz [Institute of Plasma Physics AS CR, v.v.i., Za Slovankou 1782/3, 182 00 Prague 8 (Czech Republic); Sajdl, Petr [University of Chemistry and Technology Prague, Technicka 1905, 16628 Prague 6 (Czech Republic)

    2015-09-15

    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 H{sub 2}, 500 vppm of CO and 100 vppm CH{sub 4}. 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.

  19. 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

  20. Prospects of research on hydrogen permeation and hydrogen embrittlement in 800 H and 690 alloys

    International Nuclear Information System (INIS)

    The author reviews the determining influences of hydrogen traps and surface oxidation protective films in Fe-Ni based and Ni based high temperature alloys on their anti-hydrogen permeation and anti-hydrogen embrittlement properties, and points out the key research directions related to the assessment of the anti-hydrogen permeation and anti-hydrogen embrittlement properties of 800H and 690 alloys which may be used as U-ZrH1.6 fuel cladding in compact nuclear power reactors

  1. 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.

  2. 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.)

  3. 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.

  4. Effect of different ions on the anodic behaviour of alloy 800 chloride solutions at high temperature

    International Nuclear Information System (INIS)

    The anodic behaviour and passivity breakdown of alloy 800 in sodium bicarbonate and sodium phosphate aqueous solutions were studied in the temperature range from 100 degrees C to 280 degrees C by means of electrochemical techniques. The effect of phosphate or bicarbonate additions on the pitting susceptibility and pitting morphology of the alloy in chloride solutions was also examined. Experiments were performed in the following solutions: 0.1M NaHCO3, at 100 degrees C, 200 degrees C, 280 degrees C; 0.06M NaH2PO4 + 0.04M Na2HPO4, at 100 degrees C, 200 degrees C and 280 degrees C, and 0.1M NaCl with different additions of bicarbonate ion (0.02M, 0.05M and 0.1M) and phosphate ion (0.01M, 0.05M and 0.1M) at 100 degrees C and 280 degrees C. The anodic polarization curves of alloy 800 in deaerated 0.1M NaHCO3 and 0.06M NaH2PO4 + 0.04M Na2HPO4 solutions exhibited a similar shape at all the tested temperatures. No localized or generalized corrosion was detected on the metallic surface after polarization. The results obtained in chloride plus bicarbonate and chloride plus phosphate mixtures showed that the pitting potential of alloy 800 in chloride solutions was increased by the presence of bicarbonate or phosphate ions. In those solutions where the inhibitor concentration in the mixture is equal or higher than the chloride concentration , the behaviour of the alloy is similar to the one observed in the absence of chlorides. Changes in pitting morphology were found in phosphate containing solutions, while the pits found in bicarbonate containing solutions were similar to those formed in pure chloride solutions. (author). 3 refs., 4 figs

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

    International Nuclear Information System (INIS)

    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* 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

  6. Update of alloy 800 behaviour in secondary side of PWR steam generators

    International Nuclear Information System (INIS)

    Several types of degradation are observed on the secondary side of the steam generators. But the majority of the plugged tubes are due to corrosion, as consequence of the accumulation of corrosion products and salt impurities preferentially in the flow restricted area, such as the top of the tube sheet and support plate intersections. After more than 30 years without corrosion problems in the steam generators designed by Siemens-KWU, some indications of IGA/SCC (stress corrosion cracking) in secondary are being reported. Axially oriented IGA/SCC was detected in deep tube sheet crevices in Biblis A. Recently, circumferential indications at the top of the tube sheet associated to denting have been found in the steam generators of Almaraz. This paper is aimed at revisiting the experimental program on the behaviour of Alloy 800 in secondary conditions carried out at CIEMAT at the middle of nineties to support the steam generator replacement of Almaraz 1 and 2, and Asco I and II. Alkaline and acidic environments were tested as well as AVT conditions. Special attention was paid to the effect of lead, since it was already recognized the presence of lead in the secondary side of steam generators and its potential aggressiveness for nickel base alloys. C-ring specimens were used to test Alloy 800 tubing in shot-peened and cold worked conditions, in alkaline and acidic environments with lead additions as well as in AVT condition with small lead oxide concentrations. Alloy 800 is resistant to SCC in AVT condition even with lead additions. But, it is susceptible to SCC in both alkaline and acidic environments. Solution with 4% NaOH and 80 ppm of lead oxide turned out the most aggressive for the different heats of Alloy 800 tested in alkaline environments. In addition to SCC, general corrosion provoked by lead was detected in 10% NaOH with 0.2% wt of lead oxide. Results from a model boiler test in acidic sulphates environment are also presented. (authors)

  7. 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

  8. The tensile properties of alloys 800H and 617 in the range 20 to 950deg C

    International Nuclear Information System (INIS)

    The tensile properties of Alloy 800H and Alloy 617 in the solution treated condition and after ageing or carburization have been determined for the temperature range 20 to 950deg C. It was found that ageing at 900deg C prior to testing led to an increase in strength and a decrease in ductility at test temperatures up to 700deg C. Above 700deg C, there was no significant difference between the tensile properties of solution treated and aged material. Carburization caused a severe loss of ductility in both alloys at temperatures of 20 to around 800deg C, but the ductility increased sharply at test temperatures above 800deg C, accompanied by a change in the fracture mode from fracture of the carbide particles themselves to void formation and separation at the carbide/matrix interface. The correlation between tensile properties and creep data was investigated in tests carried out at different strain rates. Reasonable agreement was found at 800 to 950deg C for Alloy 617 and at 800 to 900deg C for Alloy 800H. Strain ageing effects were observed in both alloys at some temperatures and strain rates; these effects were serrated flow, negative strain rate sensitivity, peaks in the normalized UTS-temperature curves and plateaus in the elongation-temperature curves. The experimental results were interpreted in the light of two current models for strain ageing, the dislocation-dislocation interaction model and the dislocation-solute interaction model. (orig.)

  9. Optimizing the Diffusion Welding Process for Alloy 800H: Thermodynamic, Diffusion Modeling, and Experimental Work

    Science.gov (United States)

    Mizia, Ronald E.; Clark, Denis E.; Glazoff, Michael V.; Lister, Tedd E.; Trowbridge, Tammy L.

    2013-01-01

    A research effort was made to evaluate the usefulness of modern thermodynamic and diffusion computational tools, Thermo-Calc and Dictra (Thermo_Calc Software, Inc., McMurray, PA), in optimizing the parameters for diffusion welding of Alloy 800H. This would achieve a substantial reduction in the overall number of experiments required to achieve optimal welding and post-weld heat treatment conditions. This problem is important because diffusion-welded components of Alloy 800H are being evaluated for use in assembling compact, micro-channel heat exchangers that are being proposed in the design of a high-temperature, gas-cooled reactor by the U.S. Department of Energy. The modeling was done in close contact with experimental work. The latter included using the Gleeble 3500 System (Dynamic Systems, Inc., Poestenkill, NY) for welding simulation, mechanical property measurement, and light optical and scanning electron microscopy. The modeling efforts suggested a temperature of 1423 K (1150 °C) for 1 hour with an applied pressure of 5 MPa using a 15- μm Ni foil as joint filler to reduce chromium oxidation on the welded surfaces. Good agreement between modeled and experimentally determined concentration gradients was achieved, and model refinements to account for the complexity of actual alloy materials are suggested.

  10. Optimizing the Diffusion Welding Process for Alloy 800H: Thermodynamic, Diffusion Modeling, and Experimental Work

    International Nuclear Information System (INIS)

    A research effort was made to evaluate the usefulness of modern thermodynamic and diffusion computational tools, Thermo-Calc(copyright) and Dictra(copyright), in optimizing the parameters for diffusion welding of Alloy 800H. This would achieve a substantial reduction in the overall number of experiments required to achieve optimal welding and post-weld heat treatment conditions. This problem is important because diffusion welded components of Alloy 800H are being evaluated for use in assembling compact, micro-channel heat exchangers that are being proposed in the design of a high temperature gas-cooled reactor by the US Department of Energy. The modeling was done in close contact with experimental work. The latter included using the Gleeble 3500 System(reg sign) for welding simulation, mechanical property measurement, and light optical and Scanning Electron Microscopy. The modeling efforts suggested a temperature of 1150 C for 1 hour with an applied pressure of 5 MPa using a 15 μm Ni foil as a joint filler to reduce chromium oxidation on the welded surfaces. Good agreement between modeled and experimentally determined concentration gradients was achieved, and model refinements to account for the complexity of actual alloy materials are suggested.

  11. 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

  12. Intergranular corrosion of Alloy 800 by the electrochemical potentiokinetic reactivation method

    Energy Technology Data Exchange (ETDEWEB)

    Borello, A.; La Barbera, A.; Mignone, A.; Vittori, M.

    1981-08-01

    The 'Electrochemical Potentiokinetic Reactivation' method has been employed to quantify the degree of intergranular corrosion of Alloy 800, with different Ti + Al content, aged in the range 500-650/sup 0/C for times up to 5000 hours. The results were compared with the classical Rollason's curves obtained by means of the Strauss' test and a satisfactory agreement was found. An explanation of the slight differences between both methods has been proposed on the basis of the passivity film morphology.

  13. 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.

  14. Results from investigations with an instrumented impact machine on a molybdenum base alloy, nickel base alloys, and Incoloy 800

    International Nuclear Information System (INIS)

    Experiments were performed on the molybdenum base alloy TZM, the nickel base alloys Nimocast 713 LC, Inconel 625, Nimonic 86, Hastelloy S, and the iron base alloy Incoloy 800 with an instrumented impact machine. The results are discussed in terms of absorbed impact energies and dynamic fracture toughness. In all cases the agreement between the energy determined by the dial reading and the energy determined by the integration of the load vs. load point displacement diagram was excellent. A procedure for the determination of the dynamic fracture toughness for load vs. load point displacement diagrams exhibiting high oscillations using an averaged curve is proposed. Using this procedure a pronounced influence of the experiments with tup and chisel (5.0 m/s and 0.1 m/s respectively) on the dynamic fracture toughness is not detectable. Using half the drop height, i.e. halving the total energy, lowers the dynamic fracture toughness values for these types of alloys. Low absorbed impact energies are often combined with high fracture toughness values. In these cases there is no or only a small reserve in deformation and/or stable crack growth. (Auth.)

  15. Damage mechanisms in alloy 800H at high temperatures under conditions of creep-fatigue load

    International Nuclear Information System (INIS)

    This study investigates the behaviour of the alloy 800H under cyclic load and at high temperatures. Special consideration is given to the damaging effect of additional creep load. The study aims at detecting the micromechanisms responsible for damage to the material and analysing the influence of these damage mechanism on the cyclic life. In the alloy 800H pore damages in the form of very small round pores can already be produced by cold-working and stress-free age-hardening at high temperatures, i.e. without any creep load. The thesis is evolved that the same mechanism also occurs in asymmetric high-temperature fatigue tests due to the fast athermal compression phase. This means that not only creep is responsible for creep damage in the asymmetric fatigue cycles but that also the fast compression phases can contribute actively to the pore damage besides obstructing the recovery of pore damages which developed during the creep phases due to the short time. Therefore creep fatigue should basically be described by pore damage rather than by creep damage. Fatigue life predictions as regards creep fatigue should not only consider the tension phase but also appropriately the compression phase for the development of pore damage. (orig./MM)

  16. Multiaxial creep of tubes of Alloy 800 and Alloy 617 at high temperature

    International Nuclear Information System (INIS)

    The deformation behaviour under multiaxial loading at temperature higher than 800 deg. C is strongly controlled by creep. For dimensioning and inelastic analysis the use of v. Mises theory and Norton's creep law for stationary creep are demonstrated for different combination of internal pressure and axial or torsional stress or strains. The experimental results are in satisfactory agreement with the theoretical predicted deformation behaviour if values for the coefficient k and n in Norton's creep law are used, which are close to the real creep resistance in the component. (author). 11 refs, 12 figs, 2 tabs

  17. Corrosion behaviour of Alloy 800 in high temperature aqueous solutions: long term autoclave studies

    Science.gov (United States)

    Alvarez, M. G.; Olmedo, A. M.; Villegas, M.

    1996-04-01

    Generalized corrosion of Alloy 800 under primary coolant conditions was investigated by measuring the average thickness of oxide layers grown after long isothermal exposures in the autoclaves located out of core in the Embalse Nuclear Power Plant and shorter exposures in laboratory static autoclaves. The films exhibited the familiar double layer structure but after long exposures the inner layer was found to be hidden by the formation of overlayers and/or by the deposition of species inevitably present in high temperature coolant. The samples exposed to the primary coolant showed greater average oxide thickness than those in the static autoclave studies, indicating the deposition of corrosion products from the coolant. Analysis of the films grown in static autoclaves showed the presence of hydrated species at the oxide/solution interface and spinel structures inside the film. Oxidized nickel was found only within few nanometers in the outermost layer of the films whereas elementary nickel predominated in the rest of the oxide.

  18. Examination of steam generator alloy 800 NG tube from the Almaraz unit 2 NPP

    International Nuclear Information System (INIS)

    The steam generators of Almaraz Unit 2 were replaced in 1997 by the model 61W/D3 (Siemens) with Alloy 800NG steam generator tubes. Denting indications were firstly detected in 2006 in the SG-3. Crack indications were identified in 2009. At the end of 2011, three tubes were recovered from this steam generator to carry out destructive examination in order to identify the root cause of the tubes degradation. Analysis of deposits point out the existence of multiples elements in the removed OD (Outer Diameter) deposits as well as in the deposits at the free tube under sludge and at the transition zone. Deposits are more abundant at the transition zone than at free tube. About 10% Na concentration has been detected, whereas S and Cl appear in small concentrations. Si appears regularly and Cr, Ni concentrations in the deposits are similar. Multiple intergranular cracks have been detected at 3 mm above the last contact point between the tube and the TS (tube support), in a band of around 5 mm, practically in the whole perimeter of the tube. Fracture surface of crack-B was partially covered by a Si rich layer, whereas fracture surface of crack-A seems to be cleaner. However, no significant differences in composition, except higher amount of S in crack-B, were found in the deposits of both cracks. EDX mapping and Auger profiles point out Ni enrichment with slight Cr enrichment or depletion and Fe depletion. The comparison of Auger profiles with available results for Alloy 800 tested in caustic and acid sulfate environments seems to indicate that the environment inside the cracks detected in the tube R67C48 is neutral or moderately caustic

  19. 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.)

  20. 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.)

  1. Bend-fatigue properties of JPCA and Alloy800H specimens irradiated in a spallation environment

    International Nuclear Information System (INIS)

    To evaluate the lifetime of the beam window of an accelerator-driven transmutation system (ADS) and spallation neutron source, post irradiation examination (PIE) of the STIP (SINQ target irradiation program, SINQ; Swiss spallation neutron source) specimens has been carried out. The specimens tested in this study were made from the austenitic steel JPCA (Japan Primary Candidate Alloy) and high-Ni steel Alloy800H. The specimens were irradiated at SINQ Target 4 (STIP-II) with high-energy protons and spallation neutrons. The irradiation conditions were as follows: the proton energy was 580 MeV, irradiation temperatures ranged from 120 to 350 °C and displacement damage levels ranged from 7.0 to 19.3 dpa. Bend-fatigue tests were performed in air at room temperature under deflection control mode. The wave form of the control signal was a sine curve with a frequency of 26 Hz. Fracture surface observation after the tests was done by SEM. The results on the irradiated JPCA in this study are identical to with the result of STIP-I specimens (−11 dpa). Namely, the numbers of cycles to failure (Nf) were not changed by irradiation. Dpa dependence of Nf was not clearly seen in the irradiation conditions. In spallation environment, He atom production ratio is very high and most of He atoms are retained in the materials. In spite of large number of He atoms, all JPCA specimens show transgranular fracture surface

  2. Crack growth under combined creep and fatigue conditions in alloy 800

    International Nuclear Information System (INIS)

    To investigate the crack growth behaviour under combined creep-fatigue loading, CT 25 mm-specimens of X10NiCrAlTi 32 20 (Alloy 800) have been tested in experiments with cyclic loadings and hold times, with static loadings and short stress rekief interrupts, with ramp type loadings and with sequences of separate fatigue and creep crack growth periods. The test temperature of 700deg C was selected because only in this temperature range this alloy provides similar amounts of crack growth under creep and fatigue conditions due to equivalent stress levels. For the estimation of crack growth under combined loading conditions a linear accumulation of increase in crack length was proved using the crack growth laws of pure creep and fatigue crack growth. Hold time and ramp loadings lead to a higher crack growth rate compared with pure creep or pure fatigue crack growth tests. In hold time experiments the crack growth rate is higher than ramp tests of the same period time. The results of hold time tests can be fairly enough predicted by linear damage accumulation rules. (orig.)

  3. 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.

  4. 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)

  5. Degradation of Alloy 800 steam generator tubing and its long-term behaviour predictions for plant life management

    International Nuclear Information System (INIS)

    Alloy 800 tubing has a good service record in steam generators (SGs) in both German pressurized water reactors and CANDU 6 reactors, however, a recent comprehensive examination of several ex-service SG tubes removed from Darlington Nuclear Generating Station (DNGS) found that these SG tubes (which had experienced shallow pitting in service) were more susceptible to pitting corrosion in laboratory tests than a reference nuclear grade Alloy 800 tubing under SG crevice chemistry conditions. This was an unexpected finding and has raised questions about possible effects of in-service 'aging' on SG tubing. In addition, there has also been recent evidence that a few Alloy 800 tubes have experienced stress corrosion cracking (SCC) in some German pressurized water reactors (PWRs), possibly after many years of degradation-free service, although the inspection history of these tubes is not available to confirm that the reported degradation initiated recently. These findings suggest that Alloy 800 tubing may have some aging degradation susceptibility after many years of service. To provide support for a proactive SG aging management, a survey on the corrosion susceptibility of the archived Alloy 800 tubing from CANDU SGs under plausible crevice chemistry conditions was conducted to assess the potential material degradation issues in CANDU SGs. Experimental work was also performed to investigate the root cause leading to Alloy 800 SG tubing degradation. The results from this study suggested that a combination of negative factors; aggressive chemistry resulting from impurity ingress into the secondary side of the SGs, elevated electrochemical corrosion potential (ECP) during SG transients and surface strain/plastic deformation, might have led to the degradation of the ex-service SG tubing. The studies have shown that each of these conditions in isolation does not cause degradation of Alloy 800 SG tubing; a synergistic combination of factors is required. The OPEX and experimental

  6. 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

  7. 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)

  8. 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).

  9. Microstructure optimization of austenitic Alloy 800H (Fe-21Cr-32Ni)

    International Nuclear Information System (INIS)

    Research highlights: → Presented a synergistic effect of TMP on microstructure and resulted properties. → Used AFM to quantitatively analyze geometry and distribution of GB precipitates. → Correlated GB characters with precipitates to interpret their effects on properties. → Provided evidence of coherent precipitates at coherent Σ3 boundaries. - Abstract: The microstructural evolution, specifically of grain boundaries, precipitates, and dislocations in thermomechanically processed (TMP) Alloy 800H samples was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), electron backscattered diffraction (EBSD), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The TMP not only significantly increased the fraction of low-Σ coincidence site lattice boundaries, but also introduced nanoscale precipitates in the matrix and altered the distribution of dislocations. Statistical analysis indicates that the morphology and distribution of grain boundary precipitates were dependent on grain boundary types. The microstructure optimization played a synergistic effect on the significantly increased strength with comparable ductility and enhanced intergranular corrosion resistance and creep-fatigue life compared to the as-received samples.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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...

  15. Influence of aging on low cycle fatigue and relaxation fatigue of alloy-800 grade 1 at 5500C

    International Nuclear Information System (INIS)

    Aging of alloy-800, material considered for fabrication of steam generators for fast neutron reactors, is analysed by microstructure study at different time intervals simulating long term behavior. Properties are strongly related to gamma precipitate size evolution and to a less extent by interstitial solute entrainement. Fine gamma precipitation representative of lifetime envisaged (2 x 105 hours at 5250C) localizes deformation and increases creep embrittlement. Aged materials defined by large size precipitates allowing an homogeneous deformation is ideal for the utilization envisaged

  16. Intergranular corrosion in Alloy 800: intercomparison between the Strauss test, the EPR method, and magnetic permeability measurements

    Energy Technology Data Exchange (ETDEWEB)

    Borello, A.; Mignone, A.

    1982-01-01

    The susceptibility to intergranular corrosion of different heats of Alloy 800 was evaluated by three different methods: the ASTM A 262 Practice E (or modified Strauss test), the Electrochemical Potentiokinetic Reactivation method, and by magnetic-susceptibility measurements. Reasonably good agreement was found between the sensitization areas as defined by the three methods in the TTS diagrams. In some cases the area defined by the Strauss test was slightly smaller than that determined by the other two tests. The differences might be explained by the fact that the methods present different sensitivities to the chromium concentration at the grain boundaries. 27 references, 11 figures, 3 tables.

  17. Structural evolution of alloy 800 induced by thermal aging and their consequences of the mechanical properties of the material

    International Nuclear Information System (INIS)

    One of the main characteristics of alloy 800 (used for steam generators of LMFBR reactors), an austenitic stainless steel containing Ni: 33%, Cr: 21% and addition of titanium and aluminium, is its susceptibility to secondary hardening by formation of γ' precipitates Ni3(Ti,Al). The very first stages of this precipitation have been studied using X ray diffraction and dilatometry techniques. It has been shown that the γ' phase appears during the first 500 hours between 500 and 6500C, without any time of incubation. The γ' precipitation leads to a decrease in the parameter of the austenitic matrix, this phenomena being more important with a higher (Ti+Al) content. In addition, the γ' formation induce an increase in the tensile properties at room temperature, of alloy 800 higher with a higher Ti content. Experimental results allow to drawn a graph expressing the threshold of the γ' apparition as a function of temperature. Finally, it has been shown by electronic micrography studies, that the mean radius of the particles (which remain under 200 A) follows a cubic law type r3 = Kt. The activate energy of the phenomena is about 250 KJ.mole-1

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

    Czech Academy of Sciences Publication Activity Database

    Berka, J.; Vilémová, Monika; Sajdl, P.

    2015-01-01

    Roč. 464, September (2015), s. 221-229. ISSN 0022-3115 Institutional support: RVO:61389021 Keywords : High temperature corrosion * impure helium * 800 H * Generation IV nuclear reactors Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 1.865, year: 2014 http://www.sciencedirect.com/science/article/pii/S0022311515002019#

  19. Electrochemical Behaviour of 1018, 304 and 800 Alloys in Synthetic Wastewater

    OpenAIRE

    Raúl Sandoval-Jabalera; Guadalupe V. Nevárez-Moorillón; José G. Chacón-Nava; José M. Malo-Tamayo; Alberto Martínez-Villafañe

    2006-01-01

    Debido a que los problemas de corrosión que afectan la industria de tratamiento de aguas residuales son variados y escasamente estudiados, se presenta un estudio del comportamiento de corrosión de los aceros AISI-1018, AISI-304 y AISI-800 expuestos en agua residual sintética para conocer su comportamiento bajo condiciones de laboratorio. Las técnicas electroquímicas empleadas para determinar el comportamiento de la corrosión fueron resistencia a la polarizac...

  20. The effect of bubble formation and detachment on magnetite deposition on Alloy-800 surfaces during boiling heat transfer

    International Nuclear Information System (INIS)

    Fouling of heat transfer surfaces leads to a decrease in efficiency of heat exchanger equipment. The mechanism of deposition of magnetite particles from suspension in water onto Alloy-800 heated surface can be described as five steps: initiation, transport, attachment, re-entrainment and ageing. How re-entrainment and ageing affect the overall deposition remains unclear. Nonetheless, it is believed that when the particle has been deposited, it will be either re-entrained or bonded to the surface. Experiments have been conducted in an atmospheric-pressure, recirculating water loop under isothermal, non-boiling and boiling conditions. The effect of bubbling at various heat fluxes, magnetite concentration and surface roughness on the magnetite deposition has been investigated using photographic technique. Particle trapping at the liquid-vapour interface is believed to play an important role on the magnetite deposition. The experimental results and postulated mechanisms will be presented. (author)

  1. 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...

  2. 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

  3. 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.)

  4. 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.

  5. 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

  6. 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...

  7. Evaluation of corrosion of 800GN alloy tubes in similar ambient to the secondary circuit of PWR reactor at 80 deg C

    International Nuclear Information System (INIS)

    In this work we investigated the effect of the presence of chloride ions (concentrations of 10, 50 and 250 ppb) and sulfate in a ratio of 1: 1 in a corrosion behavior of 800NG alloy tube to 80 ° C, in electrochemical cell to three electrodes. Such concentrations correspond to action levels used in the pipeline safety. Experiments in potential open circuit and cyclic polarization were used to characterize the corrosion behavior of the material. Morphological analysis of corrosion and corrosion products was performed by optical microscopy, scanning electron microscopy and X-ray diffraction. The results showed that the morphology of the attack located in a alloy 800GN is related to the ratio between the concentrations of chloride and sulfate ions in the medium

  8. 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

  9. Friction and Wear of Monolithic and Fiber Reinforced Silicon-Ceramics Sliding Against IN-718 Alloy at 25 to 800 C in Atmospheric Air at Ambient Pressure

    Science.gov (United States)

    Deadmore, Daniel L.; Sliney, Harold E.

    1988-01-01

    The friction and wear of monolithic and fiber reinforced Si-ceramics sliding against the nickel base alloy IN-718 at 25 to 800 C was measured. The monolithic materials tested were silicon carbide (SiC), fused silica (SiO2), syalon, silicon nitride (Si3N4) with W and Mg additives, and Si3N4 with Y2O3 additive. At 25 C fused silica had the lowest friction while Si3N4 (W,Mg type) had the lowest wear. At 800 C syalon had the lowest friction while Si3N4 (W,Mg type) and syalon had the lowest wear. The SiC/IN-718 couple had the lowest total wear at 25 C. At 800 C the fused silica/IN-718 couple exhibited the least total wear. SiC fiber reinforced reaction bonded silicon nitride (RBSN) composite material with a porosity of 32 percent and a fiber content of 23 vol percent had a lower coefficient of friction and wear when sliding parallel to the fiber direction than in the perpendicular at 25 C. The coefficient of friction for the carbon fiber reinforced borosilicate composite was 0.18 at 25 C. This is the lowest of all the couples tested. Wear of this material was about two decades smaller than that of the monolithic fused silica. This illustrates the large improvement in tribological properties which can be achieved in ceramic materials by fiber reinforcement. At higher temperatures the oxidation products formed on the IN-718 alloy are transferred to the ceramic by sliding action and forms a thin, solid lubricant layer which decreases friction and wear for both the monolithic and fiber reinforced composites.

  10. 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.

  11. Effect of aging and cold working on the high-temperature low-cycle fatigue behavior of alloy 800H: Part II continuous cyclic loading

    International Nuclear Information System (INIS)

    The individual and combined effects of cold working (5 and 10 pct) and aging (4000 and 8000 h in the temperature range 538 to 7600C) on the high-temperature low-cycle fatigue behavior of alloy 800H have been investigated. The specimens were tested at the aging temperatures. Both the saturation stress range and the fatigue life were found to be history dependent. A history-independent hardening mechanism, dynamic strain aging, was found to operate over the temperature range approx. 450 to 6500C and to be maximized at approx. 5500C. It is speculated that carbon is responsible for this dynamic strain aging. Finally, at temperatures above 5380C the Coffin-Manson plots indicate the possible existence of a history-independent softening mechanism

  12. 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.

  13. 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.

  14. Friction and wear of oxide-ceramic sliding against IN-718 nickel base alloy at 25 to 800 C in atmospheric air

    Science.gov (United States)

    Sliney, Harold E.; Deadmore, Daniel L.

    1989-01-01

    The friction and wear of oxide-ceramics sliding against the nickel base alloy IN-718 at 25 to 800 C were measured. The oxide materials tested were mullite (3Al2O3.2SiO2); lithium aluminum silicate (LiAlSi(x)O(y)); polycrystalline monolithic alpha alumina (alpha-Al2O3); single crystal alpha-Al2O3 (sapphire); zirconia (ZrO2); and silicon carbide (SiC) whisker-reinforced Al2O3 composites. At 25 C the mullite and zirconia had the lowest friction and the polycrystalline monolithic alumina had the lowest wear. At 800 C the Al2O3-8 vol/percent SiC whisker composite had the lowest friction and the Al2O3-25 vol/percent SiC composite had the lowest wear. The friction of the Al2O3-SiC whisker composites increased with increased whisker content while the wear decreased. In general, the wear-resistance of the ceramics improve with their hardness.

  15. Measurement of helium and hydrogen yield from irradiation of metals and alloys to ∼15 dpa in mixed spectra of 500-800 MeV protons and spallation neutrons

    International Nuclear Information System (INIS)

    Measurements have been performed of the retained helium and hydrogen levels of both pure element dosimeter foils and various structural alloys irradiated at temperatures between 30 and 60 deg. C in the Los Alamos Neutron Science Center (LANSCE) as part of the Accelerator Production of Tritium (APT) program. The elements employed as dosimeters were Al, Fe, Ni, Co and Cu. The alloys were Inconel 718, AISI 304 and 316, 9Cr-1Mo and Al 6061. Specimens irradiated to displacement levels ranging from 0.6 to ∼14 dpa were examined. Depending on the location of the individual specimen with respect to the incident proton beam, the spectral environment consisted of protons ranging downward from the incident 800 MeV to perhaps 550 MeV and a wide energy spectra of spallation neutrons. The relative contribution of neutrons to both the displacement damage level and the gas generation rates increases for specimens at the edges of the incident proton beam. The retained gas levels are a function of the elemental identity or alloy composition, spectral averaged production rates, specimen thickness, irradiation temperature and irradiation induced microstructure. While very little loss of helium is expected, significant amounts of both energetic and diffusional losses of hydrogen probably occur in the specimens during irradiation. In spite of the apparent complexity of the compositional and spectral environment, it is possible to extract very good estimates of the elemental helium generation cross sections as a function proton energy across relatively narrow energy range of ∼550-800 MeV. The data are elevated with assistance of the LAHET code system to separate the neutron contribution from the proton contribution to both gas and dpa. This effort is aided by the fact that gas generation cross section increase with energy almost in direct proportion to the dpa cross section in this proton energy range. This also allows extrapolation of these results to protons energies > 800 MeV. Due

  16. 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.

  17. 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)

  18. BN-800 - history and perspective

    International Nuclear Information System (INIS)

    The sodium cooled fast reactors are one of the most developed and advanced directions of future nuclear engineering. Russia is the first among other countries in field of fast reactor development. The idea of fast reactor designing was proposed in the former Soviet Union by Dr. A.I. Leipunski at the end of 40th. The successful operation of Russian fast reactors (BOR-60, BN-350 and BN-600 and the world experience proved the feasibility, reliability and safety of this direction of nuclear engineering and allowed to begin the development of the BN-800 reactor project as the commercial fast reactor. In 1992 Russian Government confirmed the construction of BN-800 reactors on South Ural NPP in Chelyabinsk region and on Beloyarskaya NPP. This report presents the brief review on main directions of BN-800 reactor development carrying out in IPPE. (authors)

  19. BN-800 - history and perspective

    International Nuclear Information System (INIS)

    The sodium cooled fast reactors are one of the most developed and advanced directions of future nuclear engineering. Russia is the first among other countries in field of fast reactor development. The idea of fast reactor designing was proposed in the former Soviet Union by Dr. A.I. Leipunski at the end of 40th. The successful operation of Russian fast reactors (BOR-60, BN-350 and BN-600) and the world experience proved the feasibility, reliability and safety of this direction of nuclear engineering and allowed to begin the development of the BN-800 reactor project as the commercial fast reactor. In 1992 Russian Government confirmed the construction of BN-800 reactors on South Ural NPP in Chelyabinsk region and on Beloyarsk NPP. Thus on the basis of BN-800 reactor project it is possible to design the universal fast reactor permitting to solve rather effectively the different problems of nuclear fuel cycle: from high breeding of secondary nuclear fuel to the effective transmutation of long-lived nuclear wastes depending on state of nuclear market. (authors)

  20. Improvement factors for steam generator tubing alloys

    International Nuclear Information System (INIS)

    Predictions of reliability gains associated with the use of advanced alloys have been made in the past through the use of improvement factors. Improvement factors for thermally treated Alloy 600 (Alloy 600TT) and thermally treated Alloy 690 (Alloy 690TT) steam generator tubing were previously developed and have been used in the most recent revision of the EPRI Secondary Water Chemistry Guidelines. However, due to the long expected failure times relative to field experience, field-experience-based estimates of these improvement factors continue to be overly conservative (as shown by the absence of wide spread in-service cracking of these materials). A recent study updated the previously developed improvement factors associated with the use of advanced alloys. This paper will discuss the development of relative improvement factors for Alloy 600TT, Alloy 690TT, and Alloy 800 nuclear grade (Alloy 800NG) with respect to mill annealed Alloy 600 (Alloy 600MA) steam generator tubing. The various uses which are appropriate for these improvement factors will be discussed. This presentation focuses on primary side tube degradation (PWSCC), although this project also addressed secondary side tube degradation (ODSCC). The following four techniques were used to assess the performance of the Alloy 600TT, Alloy 690TT, and Alloy 800NG relative to that of Alloy 600MA: Field data on tube degradation were evaluated using statistical techniques, based on plant population Weibull/Weibayes analyses, similar to those employed in the past and reviewed by industry experts as part of the EPRI guidelines revision process. This paper presents updated improvement factors based on further accumulation of operating experience with Alloy 600TT, Alloy 800NG, and Alloy 690TT; Field data on tube degradation were evaluated using alternative statistical techniques which are not as overly conservative as those used in the past; Field data on tube plug cracking were evaluated to compare the performance

  1. Oxidation resistant alloys, method for producing oxidation resistant alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, John S.; Alman, David E.

    2002-11-05

    A method for producing oxidation-resistant austenitic alloys for use at temperatures below 800 C. comprising of: providing an alloy comprising, by weight %: 14-18% chromium, 15-18% nickel, 1-3% manganese, 1-2% molybdenum, 2-4% silicon, 0% aluminum and the balance being iron; heating the alloy to 800 C. for between 175-250 hours prior to use in order to form a continuous silicon oxide film and another oxide film. The method provides a means of producing stainless steels with superior oxidation resistance at temperatures above 700 C. at a low cost

  2. 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...

  3. 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...

  4. 31 CFR 800.217 - Hold.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Hold. 800.217 Section 800.217 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF INVESTMENT... FOREIGN PERSONS Definitions § 800.217 Hold. The terms hold(s) and holding mean legal or...

  5. 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...

  6. 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...

  7. 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...

  8. 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... TAKEOVERS BY FOREIGN PERSONS Definitions § 800.212 Foreign entity. (a) The term foreign entity means any... corporation, or organization organized under the laws of a foreign state if either its principal place...

  9. 31 CFR 800.204 - Control.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Control. 800.204 Section 800.204... FOREIGN PERSONS Definitions § 800.204 Control. (a) The term control means the power, direct or indirect... in paragraphs (a)(1) through (9) of this section. (b) In examining questions of control in...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. Study on resistance to intergranular corrosion of heat transfer incology800H tube

    International Nuclear Information System (INIS)

    By using GB/T15260-94 B method, i.e., copper - copper sulfate -16% sulfuric acid evaluates intergranular corrosion sensitivity of nickel-based alloys, the intergranular corrosion test results of domestic heat transfer Incoloy800H tube of High-Temperature Gas-cool Reactor(HTR) nuclear power plant demonstration project are studied under different test conditions, and compared to the intergranular corrosion performance of imported Incoloy800H alloy tube. The results show that the main factors to influence the alloy resistance to intergranular corrosion are C and Ti contents, and the sensitivity increases with increasing of C content. The effective measure to prevent intergranular corrosion is to add Ti element to reduce the sensitivity to intergranular corrosion. (authors)

  18. 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.

  19. 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.

  20. 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...

  1. 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...

  2. 31 CFR 800.208 - Critical infrastructure.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Critical infrastructure. 800.208..., AND TAKEOVERS BY FOREIGN PERSONS Definitions § 800.208 Critical infrastructure. The term critical infrastructure means, in the context of a particular covered transaction, a system or asset, whether physical...

  3. 10 CFR 800.304 - Default.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Default. 800.304 Section 800.304 Energy DEPARTMENT OF ENERGY LOANS FOR BID OR PROPOSAL PREPARATION BY MINORITY BUSINESS ENTERPRISES SEEKING DOE CONTRACTS AND... section, and no deferral or restructuring is agreed to by the Secretary as provided in paragraph (d)...

  4. 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 800.303 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF INVESTMENT SECURITY, DEPARTMENT OF THE TREASURY REGULATIONS PERTAINING TO MERGERS, ACQUISITIONS,...

  5. 31 CFR 800.213 - Foreign government.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Foreign government. 800.213 Section... TAKEOVERS BY FOREIGN PERSONS Definitions § 800.213 Foreign government. The term foreign government means any government or body exercising governmental functions, other than the United States Government or...

  6. 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.

  7. 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.

  8. 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....

  9. Pitting of Incoloy 800 in presence of CuII

    International Nuclear Information System (INIS)

    The pitting behaviour of Incoloy 800 in presence of CuII ions, at 60 degrees C and 280 degrees C was studied by long term exposition of specimens in aqueous cupric chloride solutions. At 60 degrees C experiments were performed in aerated (7 ppm O2) and deaerated solutions containing 500, 1000, 2000, 10000 and 20000 ppm CuCl2. At 280 degrees C experiments were performed in deaerated 20 ppm, 50 ppm and 100 ppm CuCl2 solutions. During each experiment the open circuit potential of the alloy was measured as a function of time. After corrosion test the specimens were examined by Scanning Electron Microscopy for the presence of pits. In another set of experiments potentiodynamic anodic polarization curves were used to determine the pitting potential of Incoloy 800 in deaerated NaCl solutions at chloride concentrations and pH values corresponding to those possessed by solutions containing 20 ppm to 20000 ppm CuCl2. At 60 degrees C pitting was observed in those solutions where the CuCl2 concentration is higher than 1000 ppm. At 280 degrees C pitting was found in the specimens exposed to those solutions where the CuCl2 concentration was higher than 20 ppm. (author). 3 refs

  10. 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

  11. 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...

  12. 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.

  13. 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

  14. 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)

  15. Why incoloy 800 was selected as tube material for the new steam generators of Doel 3

    International Nuclear Information System (INIS)

    Incoloy 800 or Inconel 690. This was the basic question for the SG of DOEL 3, to be replaced in 1993. A comparative evaluation was made, focused on the service behaviour, more particularly the corrosion resistance. It was concluded that both materials may be considered for SG replacement. They are indeed substantially superior to alloy 600, but none of them is really better than the other one: - they are both nearly completely immune to primary water stress corrosion cracking; - they are both susceptible to some types of attack from the secondary side. To the 690 credit are the globally better performances in the secondary side corrosion tests. However if the aggressive environments which are unlikely to occur at DOEL 3 are discarded, it appears that the margin between 690 and 800 is small. To the 800 credit is the favourable service experience except the secondary side wastage due to phosphate conditioning. 800 was finally selected not only because of favourable economic arguments, but also because of the important weight attributed to the service behaviour by the Belgian Utilities

  16. 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...

  17. 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...

  18. 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...

  19. 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....

  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. 30 CFR 75.800-1 - Circuit breakers; location.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit breakers; location. 75.800-1 Section 75.800-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... § 75.800-1 Circuit breakers; location. Circuit breakers protecting high-voltage circuits entering...

  2. 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...

  3. 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.

  4. 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.

  5. Phase equilibria of the Ni–Si–P system at 800 °C

    International Nuclear Information System (INIS)

    Highlights: •The isothermal section at 800 °C of the Ni–Si–P system was determined. •Nine ternary phases, including three new ternary phases denoted as τ1, τ2 and τ3, were found at 800 °C. •Twenty-three-phase equilibria were determined at 800 °C for the phosphorous content range of up to 75 at.%. -- Abstract: The phase equilibria in the Ni–Si–P ternary system at 800 °C were experimentally investigated using optical microscopy, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray diffraction on 34 equilibrated alloys. Twenty-three-phase equilibria were well determined at 800 °C for the phosphorous content range of up to 75 at.%. The solubilities of P in Ni3Si, Ni5Si2, LT-Ni2Si, Ni3Si2, NiSi2and Ni3Si2, and those of Si in Ni3P, Ni2P or NiP2 does not exceed 5 at.%. The solid solubility of Ni in SiP is too small to observe. The maximum solid solubility of P in NiSi is 17.5 at.%. On the other side of the system the solubility of Si in LT-Ni5P2, LT-Ni12P5, Ni5P4 and NiP3 were measured to be 15.1 at.%, 9.4 at.%, 8.7 at.% and 5.9 at.%, respectively. The obtained phase diagrams presents nine ternary intermetallic compounds (IMCs), including three new ternary phases τ1, τ2 and τ3

  6. 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.

  7. Study of the polarization for Incoloy 800 and for the stainless stell AISI 304 in mixtures of Iron, Nickel and Chromium Chlorides

    International Nuclear Information System (INIS)

    Polarization curves for the Incoloy 800 and for the stainless stell AISI 304 were obtained with static and rotational electrodes. The electrolytes employed showed growing concentrations of mixtures as Iron, Nickel and Chromium Chlorides their proportion being the same as the content of these elements in the respective alloys. The alloys under investigation exhibited a continuous transition behaviour from the passive to the active-passive and to the active conditions. Also, the pH was found the main parameter controlling the anodic behaviour of the alloy. (Author)

  8. 31 CFR 800.226 - U.S. business.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false U.S. business. 800.226 Section 800... TAKEOVERS BY FOREIGN PERSONS Definitions § 800.226 U.S. business. The term U.S. business means any entity... subsidiary is a U.S. business. Corporation A and its branch or subsidiary is each also a foreign...

  9. 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

  10. Production and welding technology of some high-temperature nickel alloys in relation to their properties

    International Nuclear Information System (INIS)

    The most effective matching of alloys to the needs of advanced high-temperature gas-cooled reactors requires not only a knowledge of material properties, but also some understanding of the inherent general characteristics of this type of alloy. Some of the characteristic features of high-temperature nickel-based alloys are explored and general guidelines offered for their most effective use. Examples are drawn from three commercial materials: Inconel alloy 617, Incoloy alloy 800H, and Nimonic alloy 86. Such items as hot and cold working, heat treating, welding, and mechanical properties are considered

  11. Contrasting LME in aluminum and nickel alloys, with overtones to SCC

    International Nuclear Information System (INIS)

    The susceptibility of Alloys 400, 600, 200 and 800 to liquid metal embrittlement (LME), hydrogen embrittlement and stress corrosion cracking are in that order (most to least). Correlations exist, too, in the cracking mode, intergranular or transgranular. Accordingly, understanding LME and LME tests have potential uses in alloy development and screening. The use of a quick indentation test for LME is described that worked admirably for aluminum alloys but did not work for nickel-base alloys. The problem is that LME is strain rate sensitive in nickel alloys but not in aluminum alloys. This is believed to be a wetting issue

  12. 100 LPW 800 Lm Warm White LED

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Decai [Philips Lumileds Lighting Company, San Jose, CA (United States)

    2010-10-31

    An illumination grade warm white (WW) LED, having correlated color temperature (CCT) between 2800 K and 3500K and capable of producing 800 lm output at 100 lm/W, has been developed in this program. The high power WW LED is an ideal source for use as replacement for incandescent, and Halogen reflector and general purpose lamps of similar lumen value. Over the two year period, we have made following accomplishments: developed a high power warm white LED product and made over 50% improvements in light output and efficacy. The new high power WW LED product is a die on ceramic surface mountable LED package. It has four 1x1 mm{sup 2} InGaN pump dice flip chip attached to a ceramic submount in 2x2 array, covered by warm white phosphor ceramic platelets called Lumiramica and an overmolded silicone lens encapsulating the LED array. The performance goal was achieved through breakthroughs in following key areas: (1) High efficiency pump LED development through pump LED active region design and epi growth quality improvement (funded by internal programs). (2) Increase in injection efficiency (IE) represented by reduction in forward voltage (V{sub f}) through the improvement of the silver-based p-contact and a reduction in spreading resistance. The injection efficiency was increased from 80% at the start of the program to 96% at the end of the program at 700 mA/mm{sup 2}. (3) Improvement in thermal design as represented by reduction in thermal resistance from junction to case, through improvement of the die to submount connection in the thin film flip chip (TFFC) LED and choosing the submount material of high thermal conductivity. A thermal resistance of 1.72 K/W was demonstrated for the high power LED package. (4) Improvement in extraction efficiency from the LED package through improvement of InGaN die level and package level optical extraction efficiency improvement. (5) Improvement in phosphor system efficiency by improving the lumen equivalent (LE) and phosphor package

  13. Experience with 800 x 800 virtual phase and 500 x 500 three-phase CCD imagers

    Science.gov (United States)

    Hlivak, R. J.; Henry, J. P.; Pilcher, C. B.

    1984-01-01

    A description of the Galileo/Institute for Astronomy charge-coupled device (CCD) imaging system and its initial operation has been presented previously. Originally designed to operate a 500 x 500 backside illuminated three-phase CCD, the system has been modified to allow use of either the 500 x 500 sensor or the TI 800 x 800 virtual phase CCD. The modifications for the operation of the virtual phase CCD and current system performance with each type of sensor are discussed. A description is given of the implementation of various techniques discovered at the Jet Propulsion Laboratory that improve imager performance. These techniques include tri-level clocking of the virtual phase CCD to eliminate spurious charge generation in the serial register, the use of ultraviolet light flood with the backside thinned 500 x 500 three-phase device to dramatically improve the quantum efficiency in the blue, and the practical elimination of deferred charge in the three-phase device. Results of astronomical observations with each sensor are presented.

  14. 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...

  15. 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)...

  16. 24 CFR 221.800 - Cross-reference.

    Science.gov (United States)

    2010-04-01

    ... DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES LOW COST AND MODERATE INCOME MORTGAGE INSURANCE-SAVINGS CLAUSE Servicing Responsibilities-Low Cost Homes § 221.800 Cross... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Cross-reference. 221.800...

  17. 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...

  18. 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) Elevator and merchandiser recordkeeping. Every person and every State or political subdivision of a...

  19. 43 CFR 4.800 - Scope and construction of rules.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Scope and construction of rules. 4.800... of the Department of the Interior-Effectuation of Title VI of the Civil Rights Act of 1964 General § 4.800 Scope and construction of rules. (a) The rules of procedure in this subpart I supplement...

  20. 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....

  1. 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...

  2. Evolution of deformation and annealing textures in Incoloy 800H/HT via different rolling paths and strains

    International Nuclear Information System (INIS)

    In this report, we characterize the deformation and annealing textures of Incoloy 800H/HT, following different rolling conditions that produced different textures in this material. Incoloy 800H/HT is an austenitic Fe–Ni super alloy and is considered to be a candidate material for Gen IV nuclear reactors. Fossil fuel plants have used this alloy for decades; however, as grain structure and texture parameters can strongly affect its physical and mechanical properties in-service, engineers should consider some structural modifications before using this alloy in nuclear reactors. In this study, we used Thermo-Mechanical Processing (TMP) to alter the texture of Incoloy 800H/HT. We applied various thickness reductions (10%, 30%, 50%, 70%, and 90%) to this alloy using two different rolling paths, followed by annealing. Our detailed study of the deformation and annealing texture evolution shows that upon different rolling paths, the final deformation texture and the annealing texture were different. Brass texture was the dominant component for the uni-directional rolled (UDR) samples, while a combination of brass (B) and ND-rotated brass (BT) were the dominant components in the cross-rolled (CR) samples. Annealing textures of UDR samples were mainly Goss, copper, S, recrystallized brass ({236}〈385〉) and minor copper twin {552}〈115〉 components. At lower deformations (<50%), the annealed CR samples showed tilted cube, S, recrystallized brass ({236}〈385〉) and minor Goss twin (113)〈33¯2〉. However, at higher rolling reductions, the B+BT deformation texture was retained for the CR samples

  3. Phase transformations on Zr-Nb alloys

    International Nuclear Information System (INIS)

    This research intended the laboratory scale experimental development of Zr-Nb alloys with adequate characteristics for use as fuel element cladding or for the making of irradiation capsules. Zr-Nb alloys with different Nb contents were melted and the resulting material was characterised. The following metallurgical aspects were considered: preparation of Zr-Nb alloys with various Nb contents; heat and thermomechanical treatments; microstructural characterization; mechanical properties; oxidation properties. The influence of the heat treatment and thermomechanical treatment, on the out-of-pile mechanical and oxidation properties of the Zr-Nb alloys were studied. It was found that the alloy microhardness increases with the Nb content and/or with the thermomechanical treatment. Mechanical properties such as yield and ultimate tensile strength as well as elongation were determined by means of compression tests. The results showed that the alloy yield stress increases with the Nb content and with the thermomechanical treatment, while its elongation decreases. Thermogravimetric analysis determined the alloy oxidation kinetics, in the 400 - 800 deg C interval, at 1 atm. oxygen pressure. The results showed that the alloy oxidation rate increases with the temperature and Nb content. It was also observed that the oxidation rate increases considerably for temperatures higher than 600 deg C.(author)

  4. 76 FR 11681 - Improving Public Safety Communications in the 800 MHz Band; New 800 MHz Band Plan for Puerto Rico...

    Science.gov (United States)

    2011-03-03

    ... plan in the USVI as it had adopted in Puerto Rico, 75 FR 35363, June 22, 2010. The Bureau received two... systems operating in the band, 69 FR 67823, November 22, 2004. In a Third Report and Order and Third... COMMISSION 47 CFR Part 90 Improving Public Safety Communications in the 800 MHz Band; New 800 MHz Band...

  5. 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.)

  6. 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...... thermoelastic coefficients and age hardenable low expansion alloys....

  7. 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...

  8. 31 CFR 800.401 - Procedures for notice.

    Science.gov (United States)

    2010-07-01

    ...., Washington, DC 20220, that includes, in English only, the information set out in § 800.402, including the... should take place, or any draft notice should be provided, at least five business days before the...

  9. 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

  10. 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...

  11. 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...

  12. On the significance of a subsequent ageing after cold working of Incoloy 800 at operational temperatures

    International Nuclear Information System (INIS)

    The influence of cold working and subsequent ageing at operational temperatures on the long-term and short-term mechanical properties of components made from the iron-nickel-chromium base alloy Incoloy 800 are discussed. Long-term properties are time-to-rupture strengths, which are included in the design code, over a lifetime of 300,000 hours. For LWR operating temperatures of 350oC, this is of minor importance. An operating temperature of 550oC is possible for Incoloy 800 with up to 25% cold working and a subsequent solution annealing at 950oC, without loss of time-to-rupture strength compared with the 'as received' state. The short-term mechanical properties are strongly influenced by cold working, in the form of increasing yield strength and rupture strength, and decreasing ductility and consequently loss in impact energies. A subsequent ageing at 550oC leads to a decrease of the yield strength and rupture strength, and an increase of ductility as well as the impact energies. The environmental influence are discussed. (author) 3 figs., 1 tab., 8 refs

  13. 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.

  14. 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

  15. 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.

  16. R I 800. A new cobalt-60 sealed source design

    International Nuclear Information System (INIS)

    The consolidation of the international market of Co-60 sources and the perspective of its growth has encouraged the development of new types of sealed sources. The model R I 800 is designed for activities up to 65 kCi and allows a large spectrum of capsules with different specific activities. During three years Dioxitek developed the process of fabrication and qualifications to comply the design requirements and succeeded in the product approval. Today, the initial lot at an industrial scale of R I 800 sources is under fabrication and a first partial shipment of 100 kCi to the United Kingdom was successfully carried out at the end of October 2005. The whole lot is for export. Due to the versatility of the R I 800 sealed sources it was possible to use as raw material 1 MCi of Co-60 imported from Russia, irradiated in Leningrad nuclear power plant. (author)

  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. 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

  19. Effect of alloy composition on the volume fraction of beta phase in duplex titanium alloys

    International Nuclear Information System (INIS)

    Titanium alloys are strong, light, corrosion resistant and superplastic. While many of them show superplastic behavior, working and forging temperatures are still high, 850-925 degree C, and their range is narrow. Moreover, the material's resistance to deformation is not negligible and, therefore, the cost of making dies and presses for forging or hot deformation is high and it poses a serious problem. To increase the efficiency and to reduce the temperature of hot deformation, increasing the volume fraction of the beta phase present in duplex titanium alloys is suggested. With the introduction of the beta-modified Ti-6Al-4V alloy the decrease in the temperature and the increase in the strain rate of the superplastic regime promise to make superplastic forming of this alloy even more economical, and many researches have been made. In this study, efforts are put on designing new duplex alloys based on the Ti-6Al-4V and Ti-Al-Fe systems, which will have a beta volume fraction of 40-50 percent at around 800 degree C. To accomplish this, experimental volume fractions of the beta phase in several titanium alloys are being compared with predicted and calculated ones using phase equilibria analyses and some suggestions will be made on modifying the alloy compositions. For comparison, the quaternary Ti-V-Fe-Al system and their subsystems are chosen due to availability of both experimental and thermodynamic data

  20. 31 CFR 800.206 - Convertible voting instrument.

    Science.gov (United States)

    2010-07-01

    ..., 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 holder... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Convertible voting instrument....

  1. 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

  2. 30 CFR 800.11 - Requirement to file a bond.

    Science.gov (United States)

    2010-07-01

    ... regulatory program, the permit, and the reclamation plan. (b)(1) The bond or bonds shall cover the entire... regulatory authority become necessary pursuant to § 800.50. (c) An operator shall not disturb any surface... Federal program, an alternative bonding system, if it will achieve the following objectives and...

  3. Creep crack growth behavior of several structural alloys

    Science.gov (United States)

    Sadananda, K.; Shahinian, P.

    1983-07-01

    Creep crack growth behavior of several high temperature alloys, Inconel 600, Inconel 625, Inconel X-750, Hastelloy X, Nimonic PE-16, Incoloy 800, and Haynes 25 (HS-25) was examined at 540, 650, 760, and 870 °C. Crack growth rates were analyzed in terms of both linear elastic stress intensity factor and J*-integral parameter. Among the alloys Inconel 600 and Hastelloy X did not show any observable crack growth. Instead, they deformed at a rapid rate resulting in severe blunting of the crack tip. The other alloys, Inconel 625, Inconel X-750, Incoloy 800, HS-25, and PE-16 showed crack growth at one or two temperatures and deformed continuously at other temperatures. Crack growth rates of the above alloys in terms ofJ* parameter were compared with the growth rates of other alloys published in the literature. Alloys such as Inconel X-750, Alloy 718, and IN-100 show very high growth rates as a result of their sensitivity to an air environment. Based on detailed fracture surface analysis, it is proposed that creep crack growth occurs by the nucleation and growth of wedge-type cracks at triple point junctions due to grain boundary sliding or by the formation and growth of cavities at the boundaries. Crack growth in the above alloys occurs only in some critical range of strain rates or temperatures. Since the service conditions for these alloys usually fall within this critical range, knowledge and understanding of creep crack growth behavior of the structural alloys are important.

  4. Carburisation of ferritic Fe-Cr alloys by low carbon activity gases

    International Nuclear Information System (INIS)

    Highlights: → Model Fe-Cr alloys are exposed to Ar-CO2 and Ar-CO2-H2O at 650 and 800 deg. C. → Alloy microstructures are extensively modified by carburisation. → Chromium carbides precipitate at both temperatures, and martensite forms at 800 deg. C. → Elevated carbon activities reflect local equilibrium at the scale/alloy interface. - Abstract: Model Fe-Cr alloys were exposed to Ar-CO2-H2O gas mixtures at 650 and 800 deg. C. At equilibrium, these atmospheres are oxidising to the alloys, but decarburising (aC ∼ 10-15 to 10-13). In addition to developing external oxide scales, however, the alloys also carburised. Carbon supersaturation at the scale/alloy interface relative to the gas reflects local equilibrium: a low oxygen potential corresponds to a high pCO/pCO2 ratio, and hence to a high carbon activity. Interfacial carbon activities calculated on the basis of scale-alloy equilibrium are shown to be in good agreement with measured carburisation rates and precipitate volume fractions, providing support for the validity of the thermodynamic model.

  5. Compatibility of heat resistant alloys with boron carbide, 5

    International Nuclear Information System (INIS)

    This paper includes an experimental result of out-of-pile compatibility and capsule design for irradiation test in Japan Materials Testing Reactor (JMTR). The compatibility between sheath material and neutron absorber materials for control rod devices (CRD) was examined for potential use in a very high temperature reactor (VHTR) which is under development at JAERI. The purpose of the compatibility tests are preliminary evaluation of safety prior to irradiation tests. Preliminary compatibility evaluation was concerned with three items as follows : 1) Lithium effects on the penetrating reaction of Incoloy 800H alloy in contact with a mixture of boronated graphite and lithium hydroxide powders, 2) Short term tensile properties of Incoloy 800H and Hastelloy XR alloy reacted with boronated graphite and fracture mode analysis, 3) Reaction behavior of both alloys under transient power conditions of a VHTR. It was clear that the reaction rate constant of the Incoloy 800H alloy was accelerated by doping lithium hydroxide into the boron carbide and graphite powder. The mechanical properties of Incoloy 800H and Hastelloy XR alloy reacted with boronated graphite were decreased. Ultimate tensile strength and tensile ductilities at temperatures over 850 deg C were reduced, but there was no change in the proof (yield) stress. Both alloys exhibited a brittle intergranular fracture mode during transient power conditions of a VHTR and also exhibited severe penetration. Irradiation capsules for compatibility test were designed to simulate three irradiation conditions of VHTR: 1) steady state for VHTR, 2) Transient power condition, 3) Service limited life of CRD. Capsule irradiation experiments have been carried out satisfactorily and thus confirm the validity of the capsule design procedure. (author)

  6. 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...

  7. Potential resistance of Alloy 82 dissimilar metal welds to primary water stress corrosion cracking

    International Nuclear Information System (INIS)

    Joints between carbon steel and Alloy 600, containing Alloy 82 weld metal, were exposed to a steam-hydrogen environment considered to simulate exposure to primary water conditions in nuclear power plants. A potentially protective external iron oxide film formed on the inner surface of the component. However, the chromium content throughout the weld is below that which would form an external chromium oxide. The results indicate that low chromium content could allow for internal oxidation below the external iron oxide which could increase susceptibility to primary water stress corrosion cracking (PWSCC) compared with an otherwise similar alloy, such as Alloy 800. (author)

  8. 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 ...

  9. Vanadium alloys: development strategy

    International Nuclear Information System (INIS)

    A strategy for the development of vanadium alloys for use in radiation environments is outlined. An attractive reference alloy (V-15Cr-5Ti) has been identified. The critical issues in developing vanadium base alloys are summarized

  10. Magnifying lens for 800 MeV proton radiography

    International Nuclear Information System (INIS)

    This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution.

  11. 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.

  12. 120 MW, 800 MHz Magnicon for a Future Muon Collider

    International Nuclear Information System (INIS)

    Development of a pulsed magnicon at 800 MHz was carried out for the muon collider application, based on experience with similar amplifiers in the frequency range between 915 MHz and 34.3 GHz. Numerical simulations using proven computer codes were employed for the conceptual design, while established design technologies were incorporated into the engineering design. A cohesive design for the 800 MHz magnicon amplifier was carried out, including design of a 200 MW diode electron gun, design of the magnet system, optimization of beam dynamics including space charge effects in the transient and steady-state regimes, design of the drive, gain, and output cavities including an rf choke in the beam exit aperture, analysis of parasitic oscillations and design means to eliminate them, and design of the beam collector capable of 20 kW average power operation

  13. Clinical Presentation of Acute Pulmonary Embolism: Survey of 800 Cases

    OpenAIRE

    Miniati, M.; Cenci, C; Monti, S; D. Poli

    2012-01-01

    Background Pulmonary embolism (PE) is a common and potentially fatal disease that is still underdiagnosed. The objective of our study was to reappraise the clinical presentation of PE with emphasis on the identification of the symptoms and signs that prompt the patients to seek medical attention. Methodology/Principal Findings We studied 800 patients with PE from two different clinical settings: 440 were recruited in Pisa (Italy) as part of the Prospective Investigative Study of Acute Pulmona...

  14. SE received Eur 800 mill. from nine banks

    International Nuclear Information System (INIS)

    Slovenske elektrarne, a.s. (SE) received from an international consortium of nine banks a revolving credit line for seven years in the volume of Eur 800 million, approximately SKK 27.3 billion. It was confirmed by SE representatives and participating banks representatives during the signing ceremony which took place together with a press conference on 22 October 2007. This is the highest company financing in the whole history of Slovakia. (author)

  15. 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.

  16. 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.

  17. 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.

  18. Design validation and BN-800 power unit construction status

    International Nuclear Information System (INIS)

    In 2006, the Government of the Russian Federation has approved the Federal target program 'Development of nuclear power generation complex in Russia up to 2015'. Along with accelerated construction of large VVER-1000 power units, the program envisages the development of nuclear power innovative technologies. They include the activities in fast neutron reactors, which are involved in the perspective to change nuclear power over to closed fuel cycle, which provides the most efficient use of uranium resources and solution of highly actual political and ecological issues of SNF and RW handling. The central stage of the innovation component of target program deals with construction of fast sodium reactor BN-800 that shall take the important stage in development of fast breeder reactor technology and in generation of closed fuel cycle of nuclear power industry. BN-800 design has been developed on the basis of BN-600 reactor, which operates successfully at Beloyarsk NPP starting from 1980. During this period, the reactor plant shows high and stable indices of reliability, safety and efficiency. Average annual plant capacity factor of power unit from the moment of reaching of design rate (from 1982) is 75.7%. In addition, unscheduled loss of plant capacity factor value due to process equipment failures is small (∼ 2%). The final technical decisions on BN-800 were made in 1990th after Chernobyl NPP accident and following strengthening of requirements for nuclear-power safety. For qualitative safety enhancement, BN-800 design implements some predominantly passive systems (additional emergency protection rods hydraulically suspended in sodium coolant, emergency cooling air HX, tray for confining of core melt under hypothetic accident). During design upgrading, the improvements aimed at enhancement of technical-economic indices were also introduced. The main fact that allows sufficient decrease (by 34%) of RP specific metal consumption is BN-800 power increase by ∼45% at

  19. 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.

  20. 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.

  1. 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.

  2. Oxidation and volatilization of a niobium alloy

    International Nuclear Information System (INIS)

    This report presents the findings from a preliminary investigation into oxidation and volatilization characteristics of a niobium alloy. Niobium is a candidate alloy for use in plasma facing components (PFCS) in experimental fusion reactors like the Intemational Thermonuclear Experimental Reactor (ITER). An experimental alloy was tailored to simulate small changes in chemistry which could result from transmutations from irradiation. The alloy was exposed in air and steam between 800 degree C and 1200 degree C. Volatilized products and hydrogen were collected and measured. Post-test examinations were also performed on the samples to determine the amount of material loss during the exposures. The obtained measurements of volatilization flux (g/m2-s), hydrogen generation rates (liters/m2-s), and recession rates (mm/s) are data which can be used for safety analyses and material performance to predict consequences which may result from an accident involving the ingress of air or steam into the plasma chamber of fusion reactor. In our volatility tests, only molybdenum and niobium were found at release levels above the detection limit. Although molybdenum is present at only 0.12 wt%, the quantities of this element volatilized in air are nearly comparable to the quantities of niobium released. The niobium release in steam is only three to four times higher than that of molybdenum in steam. The hydrogen production of the niobium alloy is compared with other PFC materials that we have tested, specifically, beryllium, graphite, and a tunesten alloy. At high temperatures, the hydrogen production rate of the niobium alloy is among the lowest of these materials, significantly lower than beryllium. To understand what this means in an accident situation, modeling is necessary to predict temperatures, and therefore total hydrogen production. The INEL is currently doing this modeling

  3. Dislocation dynamics in SiGe alloys

    Science.gov (United States)

    Yonenaga, I.

    2013-11-01

    The dislocation velocities and mechanical strength of bulk crystals of SixGe1-x alloys grown by the Czochralski method have been investigated by the etch pit technique and compressive deformation tests, respectively. Velocity of dislocations in the SiGe alloys of the composition range 0.004 < x < 0.08 decreases monotonically with an increase in Si content at temperature 450-700°C and under stress 3-24MPa. In contrast, velocity of dislocations in the composition range 0.92 < x < 1 first increases, then decreases and again increases with a decrease in Si content at temperature 750-850°C and under stress 3-30MPa. The velocity of dislocations was quantitatively evaluated as functions of stress and temperature. Stress-strain behaviour in the yield region of the SiGe alloys of composition 0 < x < 0.4 is similar to that of Ge at temperatures lower than about 600°C. However, the yield stress becomes temperature-insensitive at high temperatures and increases with increasing Si content. The stress-strain curves of the SiGe alloys of composition 0.95 < x < 1 are similar to those of pure Si at temperatures 800-1000°C and the yield stress increases with decreasing Si content down to x = 0.95. The yield stress of the SiGe alloys is dependent on the composition, being proportional to x(1-x), showing a maximum around x ≈ 0.5. Built-in stress fields related to local fluctuation of the alloy composition and the dynamic development of a solute atmosphere around the dislocations, may suppress the activities of dislocations and lead to the hardening of SiGe alloys.

  4. Dislocation dynamics in SiGe alloys

    International Nuclear Information System (INIS)

    The dislocation velocities and mechanical strength of bulk crystals of SixGe1−x alloys grown by the Czochralski method have been investigated by the etch pit technique and compressive deformation tests, respectively. Velocity of dislocations in the SiGe alloys of the composition range 0.004 < x < 0.08 decreases monotonically with an increase in Si content at temperature 450–700°C and under stress 3–24MPa. In contrast, velocity of dislocations in the composition range 0.92 < x < 1 first increases, then decreases and again increases with a decrease in Si content at temperature 750-850°C and under stress 3–30MPa. The velocity of dislocations was quantitatively evaluated as functions of stress and temperature. Stress-strain behaviour in the yield region of the SiGe alloys of composition 0 < x < 0.4 is similar to that of Ge at temperatures lower than about 600°C. However, the yield stress becomes temperature-insensitive at high temperatures and increases with increasing Si content. The stress-strain curves of the SiGe alloys of composition 0.95 < x < 1 are similar to those of pure Si at temperatures 800–1000°C and the yield stress increases with decreasing Si content down to x = 0.95. The yield stress of the SiGe alloys is dependent on the composition, being proportional to x(1−x), showing a maximum around x ≈ 0.5. Built-in stress fields related to local fluctuation of the alloy composition and the dynamic development of a solute atmosphere around the dislocations, may suppress the activities of dislocations and lead to the hardening of SiGe alloys

  5. Deposition of silica coatings on Incoloy 800H substrates using a high power laser

    International Nuclear Information System (INIS)

    Using a 5kW CO2 laser, thin silica coatings have been deposited on steeply inclined Inccoloy 800H substrates traversed beneath the incident laser beam. The small angle of incidence (10deg-15deg) of the beam on the substrate resulting from the large angle of incline gave reduced substrate heating and eliminated melting of the substrate surface, but allowed melting of the silica powder injection into the focus of the beam. The focus was positioned above the substrate and the molten powder was allowed to fall onto the laser-heated substrate below. By making overlapping passes, complete surface coverage was achieved over a large area, the coating thickness being 2-3μm; this overlap filled points of surface roughness to give the component a microscopically smooth outer appearance. The silica coating formed a good bond with the metallic substrate; adhesion appeared to be improved by having a slightly rough finish rather than a highly polished one. Resistance to sulphidation attach was assessed by placing coated samples in a furnace containing a mixture of gases as in a simulated coal gasifer heat exchanger atmosphere at 450 and 750degC. Sulphidation resistance was greatly improved from that of the untreated alloy and the coating did not spall or crack for the period of the test; the few sulphides observed were probably formed at small discontunuities in the coating which may be eliminated by applying a second silica coating. (orig.)

  6. 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

  7. Clinical presentation of acute pulmonary embolism: survey of 800 cases.

    Directory of Open Access Journals (Sweden)

    Massimo Miniati

    Full Text Available BACKGROUND: Pulmonary embolism (PE is a common and potentially fatal disease that is still underdiagnosed. The objective of our study was to reappraise the clinical presentation of PE with emphasis on the identification of the symptoms and signs that prompt the patients to seek medical attention. METHODOLOGY/PRINCIPAL FINDINGS: We studied 800 patients with PE from two different clinical settings: 440 were recruited in Pisa (Italy as part of the Prospective Investigative Study of Acute Pulmonary Embolism Diagnosis (PISAPED; 360 were diagnosed with and treated for PE in seven hospitals of central Tuscany, and evaluated at the Atherothrombotic Disorders Unit, Firenze (Italy, shortly after hospital discharge. We interviewed the patients directly using a standardized, self-administered questionnaire originally utilized in the PISAPED. The two samples differed significantly as regards age, proportion of outpatients, prevalence of unprovoked PE, and of active cancer. Sudden onset dyspnea was the most frequent symptom in both samples (81 and 78%, followed by chest pain (56 and 39%, fainting or syncope (26 and 22%, and hemoptysis (7 and 5%. At least one of the above symptoms was reported by 756 (94% of 800 patients. Isolated symptoms and signs of deep vein thrombosis occurred in 3% of the cases. Only 7 (1% of 800 patients had no symptoms before PE was diagnosed. CONCLUSIONS/SIGNIFICANCE: Most patients with PE feature at least one of four symptoms which, in decreasing order of frequency, are sudden onset dyspnea, chest pain, fainting (or syncope, and hemoptysis. The occurrence of such symptoms, if not explained otherwise, should alert the clinicians to consider PE in differential diagnosis, and order the appropriate objective test.

  8. Translating VDM to Alloy

    DEFF Research Database (Denmark)

    Lausdahl, Kenneth

    2013-01-01

    specifications. However, to take advantage of the automated analysis of Alloy, the model-oriented VDM specifications must be translated into a constraint-based Alloy specifications. We describe how a sub- set of VDM can be translated into Alloy and how assertions can be expressed in VDM and checked by the Alloy...

  9. 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.

  10. 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.

  11. Hydrogen embrittlement for austenitic alloys: behaviour of microstructure and segregation of sulphur and phosphorus impurities

    International Nuclear Information System (INIS)

    The mechanical properties of austenitic alloys can be highly modified in the presence of a hydrogenation. The purpose of this study is to specify this influence on two alloys (800 and 600) for which the chemical composition on the one hand, and the microstructure on the other hand have significant differences. The hydrogenation was done before tensile testing under potentiostatic cathodic polarization at 300 deg c for times varying between 5 and 48 h. A high embrittlement from the hydrogen was shown in the case of the alloy 600 in the quenched annealed state with precipitates at the grain boundaries. It is lower in the quenched state without precipitates at the grain boundaries. On the other hand, the alloy 800 is not embrittled by the hydrogen, neither in the quenched state nor in the annealed state, even in the presence of precipitates. The influence of a phosphorus segregation on the grain boundaries can explain the differences observed. (authors)

  12. Stress Corrosion Cracking of Ni-Fe-Cr Alloys Relevant to Nuclear Power Plants

    Science.gov (United States)

    Persaud, Suraj

    Stress corrosion cracking (SCC) of Ni-Fe-Cr alloys and weld metals was investigated in simulated environments representative of high temperature water used in the primary and secondary circuits of nuclear power plants. The mechanism of primary water SCC (PWSCC) was studied in Alloys 600, 690, 800 and Alloy 82 dissimilar metal welds using the internal oxidation model as a guide. Initial experiments were carried out in a 480°C hydrogenated steam environment considered to simulate high temperature reducing primary water. Ni alloys underwent classical internal oxidation intragranularly resulting in the expulsion of the solvent metal, Ni, to the surface. Selective intergranular oxidation of Cr in Alloy 600 resulted in embrittlement, while other alloys were resistant owing to their increased Cr contents. Atom probe tomography was used to determine the short-circuit diffusion path used for Ni expulsion at a sub-nanometer scale, which was concluded to be oxide-metal interfaces. Further exposures of Alloys 600 and 800 were done in 315°C simulated primary water and intergranular oxidation tendency was comparable to 480°C hydrogenated steam. Secondary side work involved SCC experiments and electrochemical measurements, which were done at 315°C in acid sulfate solutions. Alloy 800 C-rings were found to undergo acid sulfate SCC (AcSCC) to a depth of up to 300 microm in 0.55 M sulfate solution at pH 4.3. A focused-ion beam was used to extract a crack tip from a C-ring and high resolution analytical electron microscopy revealed a duplex oxide structure and the presence of sulfur. Electrochemical measurements were taken on Ni alloys to complement crack tip analysis; sulfate was concluded to be the aggressive anion in mixed sulfate and chloride systems. Results from electrochemical measurements and crack tip analysis suggested a slip dissolution-type mechanism to explain AcSCC in Ni alloys.

  13. Microstructure, transformation behavior and mechanical properties of a (Ti50Ni38Cu12)93Nb7 alloy

    International Nuclear Information System (INIS)

    A (Ti50Ni38Cu12)93Nb7 alloy is fabricated by arc melting, forging and drawing. The microstructure, transformation behavior and mechanical properties were investigated by means of scanning electron microscope (SEM), differential scanning calorimeter (DSC), dynamic mechanical analyzer (DMA) and tensile test machine. SEM observation showed that the as cast alloy is composed of TiNiCu and Nb-rich phases. After drawing, the alloy showed single step transformations during heating and cooling within the whole annealing temperature range from 400 °C to 800 °C. With the increase of the annealing temperature, both the transformation temperatures and the damping capacity increased first and then decreased. The ultimate strength of the alloy after annealing at 400 °C is over 1500 MPa and the maximum elongation of the alloy after annealing at 800 °C is more than 20%

  14. 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)

  15. 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

  16. 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.

  17. 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.

  18. 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.)

  19. Microstructure and Mechanical Behavior of High-Entropy Alloys

    Science.gov (United States)

    Licavoli, Joseph J.; Gao, Michael C.; Sears, John S.; Jablonski, Paul D.; Hawk, Jeffrey A.

    2015-10-01

    High-entropy alloys (HEAs) have generated interest in recent years due to their unique positioning within the alloy world. By incorporating a number of elements in high proportion, usually of equal atomic percent, they have high configurational entropy, and thus, they hold the promise of interesting and useful properties such as enhanced strength and alloy stability. The present study investigates the mechanical behavior, fracture characteristics, and microstructure of two single-phase FCC HEAs CoCrFeNi and CoCrFeNiMn with some detailed attention given to melting, homogenization, and thermo-mechanical processing. Ingots approaching 8 kg in mass were made by vacuum induction melting to avoid the extrinsic factors inherent to small-scale laboratory button samples. A computationally based homogenization heat treatment was given to both alloys in order to eliminate any solidification segregation. The alloys were then fabricated in the usual way (forging, followed by hot rolling) with typical thermo-mechanical processing parameters employed. Transmission electron microscopy was subsequently used to assess the single-phase nature of the alloys prior to mechanical testing. Tensile specimens (ASTM E8) were prepared with tensile mechanical properties obtained from room temperature through 800 °C. Material from the gage section of selected tensile specimens was extracted to document room and elevated temperature deformation within the HEAs. Fracture surfaces were also examined to note fracture failure modes. The tensile behavior and selected tensile properties were compared with results in the literature for similar alloys.

  20. 30 CFR 912.800 - General requirements for bonding of surface coal mining and reclamation operations.

    Science.gov (United States)

    2010-07-01

    ... coal mining and reclamation operations. 912.800 Section 912.800 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE IDAHO § 912.800 General requirements for bonding of surface coal mining...

  1. 30 CFR 933.800 - General requirements for bonding of surface coal mining and reclamation operations.

    Science.gov (United States)

    2010-07-01

    ... coal mining and reclamation operations. 933.800 Section 933.800 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE NORTH CAROLINA § 933.800 General requirements for bonding of surface coal...

  2. 30 CFR 939.800 - General requirements for bonding of surface coal mining and reclamation operations.

    Science.gov (United States)

    2010-07-01

    ... coal mining and reclamation operations. 939.800 Section 939.800 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE RHODE ISLAND § 939.800 General requirements for bonding of surface coal...

  3. 30 CFR 921.800 - General requirements for bonding of surface coal mining and reclamation operations.

    Science.gov (United States)

    2010-07-01

    ... coal mining and reclamation operations. 921.800 Section 921.800 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE MASSACHUSETTS § 921.800 General requirements for bonding of surface coal...

  4. 30 CFR 910.800 - General requirements for bonding of surface coal mining and reclamation operations.

    Science.gov (United States)

    2010-07-01

    ... coal mining and reclamation operations. 910.800 Section 910.800 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE GEORGIA § 910.800 General requirements for bonding of surface coal mining...

  5. 30 CFR 941.800 - General requirements for bonding of surface coal mining and reclamation operations.

    Science.gov (United States)

    2010-07-01

    ... coal mining and reclamation operations. 941.800 Section 941.800 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE SOUTH DAKOTA § 941.800 General requirements for bonding of surface coal...

  6. 30 CFR 922.800 - General requirements for bonding of surface coal mining and reclamation operations.

    Science.gov (United States)

    2010-07-01

    ... coal mining and reclamation operations. 922.800 Section 922.800 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE MICHIGAN § 922.800 General requirements for bonding of surface coal mining...

  7. 30 CFR 937.800 - General requirements for bonding of surface coal mining and reclamation operations.

    Science.gov (United States)

    2010-07-01

    ... coal mining and reclamation operations. 937.800 Section 937.800 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE OREGON § 937.800 General requirements for bonding of surface coal mining...

  8. 30 CFR 942.800 - Bond and insurance requirements for surface coal mining and reclamation operations.

    Science.gov (United States)

    2010-07-01

    ... coal mining and reclamation operations. 942.800 Section 942.800 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE TENNESSEE § 942.800 Bond and insurance requirements for surface coal mining...

  9. 7 CFR 4290.800 - Financings in the form of Equity Securities.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Financings in the form of Equity Securities. 4290.800 Section 4290.800 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS...-Types of Financings § 4290.800 Financings in the form of Equity Securities. You may purchase the...

  10. 13 CFR 108.800 - Financings in the form of equity interests.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Financings in the form of equity interests. 108.800 Section 108.800 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NEW MARKETS...'s Financing of Eligible Small Businesses § 108.800 Financings in the form of equity interests....

  11. 7 CFR 800.197 - Approval as a scale testing and certification organization.

    Science.gov (United States)

    2010-01-01

    ... organization. 800.197 Section 800.197 Agriculture Regulations of the Department of Agriculture (Continued... § 800.197 Approval as a scale testing and certification organization. (a) Who may apply. Any State... to test weighing equipment and has a working knowledge of the regulations and instructions...

  12. 31 CFR 800.506 - Completion or termination of investigation and report to the President.

    Science.gov (United States)

    2010-07-01

    ... investigation and report to the President. 800.506 Section 800.506 Money and Finance: Treasury Regulations... and Investigation § 800.506 Completion or termination of investigation and report to the President. (a... report to the President requesting the President's decision if: (1) The Committee recommends that...

  13. 30 CFR 75.800-4 - Testing, examination, and maintenance of circuit breakers; record.

    Science.gov (United States)

    2010-07-01

    ... circuit breakers; record. 75.800-4 Section 75.800-4 Mineral Resources MINE SAFETY AND HEALTH... Underground High-Voltage Distribution § 75.800-4 Testing, examination, and maintenance of circuit breakers... adjustment of all circuit breakers protecting high-voltage circuits which enter any underground area of...

  14. 30 CFR 75.800-3 - Testing, examination and maintenance of circuit breakers; procedures.

    Science.gov (United States)

    2010-07-01

    ... High-Voltage Distribution § 75.800-3 Testing, examination and maintenance of circuit breakers; procedures. (a) Circuit breakers and their auxiliary devices protecting underground high-voltage circuits... breakers; procedures. 75.800-3 Section 75.800-3 Mineral Resources MINE SAFETY AND HEALTH...

  15. 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...

  16. 38 CFR 3.800 - Disability or death due to hospitalization, etc.

    Science.gov (United States)

    2010-07-01

    ... benefits under 38 U.S.C. chapter 39 (38 CFR 3.808), and if VA awards chapter 39 benefits after the date on... to hospitalization, etc. 3.800 Section 3.800 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF... Benefits § 3.800 Disability or death due to hospitalization, etc. This section applies to claims...

  17. 78 FR 42526 - Compliance Policy Guide Sec. 690.800 Salmonella

    Science.gov (United States)

    2013-07-16

    ... HUMAN SERVICES Food and Drug Administration Compliance Policy Guide Sec. 690.800 Salmonella in Food for... ``Compliance Policy Guide Sec. 690.800 Salmonella in Food for Animals'' (the CPG). The CPG provides guidance to... the availability of a guidance document entitled ``Compliance Policy Guide Sec. 690.800 Salmonella...

  18. 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)

  19. 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.

  20. 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

  1. Low Activation Vanadium Alloys for Fusion Power Reactors - the RF Results

    International Nuclear Information System (INIS)

    Full text: The Results of development and researches of functional properties of low activation vanadium alloys (V-Ti-Cr and V-Cr-W-Zr-C systems) being developed for the cores of nuclear fusion and fission (Gen-IV, space) power reactors are presented. Scientific and technological problems of the investigations are related with enhancement of functional properties based on: 1. Special optimized thermal (TT), thermomechanical (TMT) and thermochemical (TCT) treatments of V-4Ti-4Cr alloys. 2. Development of new (V-Cr-W-Zr-C system) vanadium alloys. The TMT and TCT regimes ensuring the capability of significant (up to 2 times) enhancement of yield strength in the temperature range up to 800°C keeping relatively high plasticity reserve have been found for alloys. The results of the theoretical, modeling and simulating studies of characteristics of self-point defects and dislocations, their interactions and mobility are presented. Nuclear physics characteristics (primary radiation damage, activation, transmutation, postreactor cooling) of alloys irradiated for a long time in neutron spectra of the fusion reactor DEMO-RF (15.3 dpa/year) and fast power reactor BN-600 (80 dpa/year) are calculated. The interaction characteristics of V-4Ti-4Cr alloy with hydrogen and the influence of hydrogen on mechanical properties of the alloy (impact toughness, internal friction) have been studied. Obtained results allows one to recommend the vanadium alloys for applications in nuclear reactors at operating temperature window 300 - 800(850)°C. The planes of high-dose and high- temperature reactor tests of vanadium alloys are scheduled at material science assemblies of reactor BN-600 (2013 - 2015, doses 50 - 200 dpa, irradiation temperatures 400 - 800°C). (author)

  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. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Science.gov (United States)

    2010-10-01

    ... Business/Industrial Land Transportation Pool. (a) Definition. Except as provided in 47 CFR 90.617(k... 47 Telecommunication 5 2010-10-01 2010-10-01 false Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part 22 Cellular Radiotelephone systems, and within...

  4. 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.

  5. 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.

  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. Microstructure and Mechanical Properties of the Ti-45Al-5Fe Intermetallic Alloy

    Science.gov (United States)

    Nazarova, T. I.; Imayev, V. M.; Imayev, R. M.

    2015-10-01

    Microstructure including changes in the phase composition and mechanical compression properties of the Ti-45Al-5Fe (at.%) intermetallic alloy manufactured by casting and subjected to homogenization annealing are investigated as functions of the temperature. The initial alloy has a homogeneous predominantly lamellar structure with relatively small size of colonies of three intermetallic phases: γ(TiAl), τ2(Al2FeTi), and α2(Ti3Al) in the approximate volume ratio 75:20:5. Compression tests have revealed the enhanced strength at room temperature and the improved hot workability at 800°C compared to those of TNM alloys of last generation.

  8. Thermal cycling influence on microstructural characterization of alloys with high nickel content

    International Nuclear Information System (INIS)

    The IV nuclear energy generation systems are aimed at making revolutionary improvements in economics, safety and reliability, and sustainability. To achieve these goals, Generation IV systems will operate at higher temperatures and in higher radiation fields. This paper shows the thermal cycling influences on microstructure and hardness of nickel based alloys: Incoloy 800 HT and Inconel 617. These alloys were meekly at a thermal cycling of 25, 50, 75 and 100 cycles. The temperature range of a cycle was between 400OC and 700OC. Nickel base alloys develop their properties by solid solution and/or precipitation strengthening. (authors)

  9. 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...

  10. 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...

  11. Terbium base alloy

    International Nuclear Information System (INIS)

    Composition of terbium-5-7 % gadolinium alloy with high magnetostriction sensitivity (180x10-8 Oe) is suggested. The alloy is designed for usage under cryogenic temperature within 500-1500 Oe fields. Magnetostriction sensitivity of the suggested alloy is by 2-2.5 times higher, than that of well-known before one. 1 tab

  12. F-Alloy: An Alloy Based Model Transformation Language

    OpenAIRE

    Gammaitoni, Loïc; Kelsen, Pierre

    2015-01-01

    Model transformations are one of the core artifacts of a model-driven engineering approach. The relational logic language Alloy has been used in the past to verify properties of model transformations. In this paper we introduce the concept of functional Alloy modules. In essence a functional Alloy module can be viewed as an Alloy module representing a model transformation. We describe a sublanguage of Alloy called F-Alloy that allows the specification of functional Alloy modules. Module...

  13. 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

  14. 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.

  15. Oxidation behavior of Incoloy 800 under simulated supercritical water conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fulger, M. [Institute for Nuclear Research Pitesti, POB 78, Campului Street, No. 1, 115400 Mioveni (Romania)], E-mail: manuela.fulger@nuclear.ro; Ohai, D.; Mihalache, M.; Pantiru, M. [Institute for Nuclear Research Pitesti, POB 78, Campului Street, No. 1, 115400 Mioveni (Romania); Malinovschi, V. [University of Pitesti, Research Center for Advanced Materials, Targul din Vale Street, No. 1, 110040 Pitesti (Romania)

    2009-03-31

    For a correct design of supercritical water-cooled reactor (SCWR) components, data regarding the behavior of candidate materials in supercritical water are necessary. Corrosion has been identified as a critical problem because the high temperature and the oxidative nature of supercritical water may accelerate the corrosion kinetics. The goal of this paper is to investigate the oxidation behavior of Incoloy 800 exposed in autoclaves under supercritical water conditions for up to 1440 h. The exposure conditions (thermal deaerated water, temperatures of 723, 773, 823 and 873 K and a pressure of 25 MPa) have been selected as relevant for a supercritical power plant concept. To investigate the structural changes of the oxide films, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and electrochemical impedance spectroscopy (EIS) analyses were used. Results show changes in the oxides chemical composition, microstructure and thickness versus testing conditions (pressure, temperature and time). The oxide films are composed of two layers: an outer layer enriched in Fe oxide and an inner layer enriched in Cr and Ni oxides corresponding to small cavities supposedly due to internal oxidation.

  16. 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...

  17. 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.

  18. 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.

  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. 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.

  1. 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.

  2. 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.)

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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)

  8. 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.

  9. 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.

  10. Screening test results on potential alternate alloys for VHTGR applications. Advanced Gas Cooled Reactor Materials Program

    International Nuclear Information System (INIS)

    General Electric is working to define and develop the materials technology which will be required for advanced very High Temperature Gas Reactors operating at primary coolant temperatures up to 9500C. The most promising application which has been identified is providing process heat for the reforming of methane. Earlier work had identified Inconel 617 and Alloy 800H as the best of the commercially available alloys for the reformer components. Since these alloys were identified, additional alloys have been developed which may offer improved performance over the above reference reformer alloys. This report presents the results obtained to date on four possible alternate alloys, Nimonic 86, Sanicro 32X, SSS-113-MA, and X 8 NiCrMoNb 16 16, which are being evaluated by General Electric for thermal stability and compatibility with HTGR helium environments. The thermal stabilities of Nimonic 86, Sanicro 32X, and X 8 NiCrMoNb 16 16 have been shown to be good out to maximum exposure times and temperatures of 6000 hours and 9500C, respectively. The thermal stability, as measured by room temperature impact strength, and post exposure ductility of the Japanese developmental alloy SSS-113-MA have been shown to be poor. Measured impact strengths and ductilities below 15 ft-lbs and 10%, respectively, have been observed for this alloy. No conclusions regarding the helium compatibility of the alloys can be made at this time because of the limited data available

  11. The DynAlloy Visualizer

    OpenAIRE

    Bendersky, Pablo; Galeotti, Juan Pablo; Garbervetsky, Diego

    2014-01-01

    We present an extension to the DynAlloy tool to navigate DynAlloy counterexamples: the DynAlloy Visualizer. The user interface mimics the functionality of a programming language debugger. Without this tool, a DynAlloy user is forced to deal with the internals of the Alloy intermediate representation in order to debug a flaw in her model.

  12. 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.

  13. 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

  14. 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...

  15. 31 CFR 800.503 - Determination of whether to undertake an investigation.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Determination of whether to undertake... Investigation § 800.503 Determination of whether to undertake an investigation. (a) After a review of a notified transaction under § 800.502, the Committee shall undertake an investigation of any transaction that it...

  16. Study on stretch bendability and shear fracture of 800 MPa dual phase steel sheet

    International Nuclear Information System (INIS)

    Highlights: • Stretch bendability was studied for 800 MPa dual phase steel sheet (DP800). • The stress state plays a significant role in the failure mechanism of DP800. • Microstructure evolution during fracture was observed by SEM. • DP800 exhibits shear fracture at all R/t ratios except the highest R/t ratio. - Abstract: The stretch bendability and shear fracture of 800 MPa dual phase (DP) sheet steel under different punch radii has been experimentally studied in this paper. Its fracture mechanism has also been discussed with the help of scanning electron microscope (SEM) observation. The results show that the fracture mode of DP800 stretch bending experience a transition from shear fracture to necking before fracture with R/t ratios increasing. The SEM observation on the fractograph reveals that the rupture mode of DP800 is shear dimple pattern at tight punch radii, which can be attributed to the strain localization and void shearing behavior. From the examination of microstructure evolution near the fracture surface, it was found that the stress state plays a significant role in the failure mechanism of DP800. Moreover, the stamping robustness of ultrahigh strength DP steels was discussed and the fracture mechanism was investigated

  17. 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...

  18. 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...

  19. 45 CFR 2522.800 - How will the Corporation evaluate individual AmeriCorps programs?

    Science.gov (United States)

    2010-10-01

    ... based on earning a high school diploma or its equivalent and future enrollment in and completion of... 45 Public Welfare 4 2010-10-01 2010-10-01 false How will the Corporation evaluate individual AmeriCorps programs? 2522.800 Section 2522.800 Public Welfare Regulations Relating to Public...

  20. 30 CFR 947.800 - Requirements for bonding of surface coal mining and reclamation operations.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Requirements for bonding of surface coal mining and reclamation operations. 947.800 Section 947.800 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING...

  1. 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.

  2. 78 FR 42701 - Improving Public Safety Communications in the 800 MHz Band

    Science.gov (United States)

    2013-07-17

    ... respect to one aspect of the Report and Order, 73 FR 67794, November 17, 2008, in this proceeding, to...&O. See Report and Order (800 MHz R&O), 69 FR 67823, November 22, 2004; Supplemental Report and Order on Reconsideration (800 MHz Supplemental R&O), 70 FR 6758, February 8, 2005. Shortly thereafter,...

  3. 30 CFR 77.800-1 - Testing, examination, and maintenance of circuit breakers; procedures.

    Science.gov (United States)

    2010-07-01

    ... circuit breakers; procedures. 77.800-1 Section 77.800-1 Mineral Resources MINE SAFETY AND HEALTH..., examination, and maintenance of circuit breakers; procedures. (a) Circuit breakers and their auxiliary devices... circuit breaker and its auxiliary devices, and such repairs or adjustments as are indicated by such...

  4. 30 CFR 77.800-2 - Testing, examination, and maintenance of circuit breakers; record.

    Science.gov (United States)

    2010-07-01

    ... circuit breakers; record. 77.800-2 Section 77.800-2 Mineral Resources MINE SAFETY AND HEALTH..., examination, and maintenance of circuit breakers; record. The operator shall maintain a written record of each test, examination, repair, or adjustment of all circuit breakers protecting high-voltage circuits....

  5. 22 CFR 1006.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-04-01

    ... procurement debarment by any Federal agency taken pursuant to 48 CFR part 9, subpart 9.4, before August 25... 22 Foreign Relations 2 2010-04-01 2010-04-01 true What are the causes for debarment? 1006.800... (NONPROCUREMENT) Debarment § 1006.800 What are the causes for debarment? We may debar a person for— (a)...

  6. 21 CFR 1404.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-04-01

    ... taken before October 1, 1988, or a procurement debarment by any Federal agency taken pursuant to 48 CFR... 21 Food and Drugs 9 2010-04-01 2010-04-01 false What are the causes for debarment? 1404.800... SUSPENSION (NONPROCUREMENT) Debarment § 1404.800 What are the causes for debarment? We may debar a person...

  7. 2 CFR 180.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-01-01

    ... taken before October 1, 1988, or a procurement debarment by any Federal agency taken pursuant to 48 CFR... 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...

  8. 29 CFR 1471.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-07-01

    ... 48 CFR part 9, subpart 9.4, before August 25, 1995; (2) Knowingly doing business with an ineligible... 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...

  9. 22 CFR 208.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-04-01

    ... taken before October 1, 1988, or a procurement debarment by any Federal agency taken pursuant to 48 CFR... 22 Foreign Relations 1 2010-04-01 2010-04-01 false What are the causes for debarment? 208.800... SUSPENSION (NONPROCUREMENT) Debarment § 208.800 What are the causes for debarment? We may debar a person...

  10. 22 CFR 1508.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-04-01

    ... procurement debarment by any Federal agency taken pursuant to 48 CFR part 9, subpart 9.4, before August 25... 22 Foreign Relations 2 2010-04-01 2010-04-01 true What are the causes for debarment? 1508.800... (NONPROCUREMENT) Debarment § 1508.800 What are the causes for debarment? We may debar a person for— (a)...

  11. 7 CFR 800.148 - Maintenance and retention of records on organization, staffing, and budget.

    Science.gov (United States)

    2010-01-01

    ..., staffing, and budget. 800.148 Section 800.148 Agriculture Regulations of the Department of Agriculture... retention of records on organization, staffing, and budget. (a) Organization. Agencies, contractors, and... current employee, (2) each employee's principal duty, (3) each employee's principal duty station,...

  12. Electrochemical and surface characterisation of oxide films on nano-grain nickel films electrodeposited on INCOLOY-800

    International Nuclear Information System (INIS)

    Nano materials have different properties from the corresponding bulk materials because of fine grain size, large fraction of surface atoms, high surface energy and high grain boundary volume fraction. For similar reasons, the nano-alloy coatings show superior high-temperature corrosion resistance and are generally more resistant to stress corrosion cracking. Hence, it is of interest to know the materials performance, if the structural materials used in nuclear reactors are made of nano-grains. In Indian PHWRs, Incoloy-800 is being used as the steam generator tubing material. It's corrosion resistance property is very important as it forms not only the pressure boundary between the radioactive primary water and non-active secondary water but also from the view point of loss of heavy water, in case of any corrosion damage. In this paper, the corrosion resistance of the oxide films formed on nano-grain nickel film electrodeposited on Incoloy-800 (a) in the presence of saccharine (WS) and (b) in the absence of saccharine (WOS) were compared with that formed on Commercial Ni foil, using electrochemical dc polarization and ac impedance techniques. The surface morphology, elemental analysis and grain size were studied with SEM, EDX and XRD techniques respectively. The nano-grain nickel films were prepared on Incoloy-800 by electrodeposition using Watt's Bath with saccharine sodium as a surfactant. The oxide films were developed by exposing them to LiOH solution (pH-10.0) at 245 deg C for 3 days (A-group) and 7 days (B-group). XRD results showed that the grain size of Ni formed in the absence of saccharine (WOS) was ∼ 60 nm and did not change after being autoclaved. But, for Ni formed in the presence of saccharine (WS), the grain size was ∼ 16 nm which increased to 40-50 nm after being autoclaved. With both A and B-group specimens, the PDAP curves showed an active-passive transition, a passive region and a transpassive region in 2N H2SO4. However, the critical current

  13. 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

  14. 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.

  15. 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).

  16. 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.

  17. Hydrogen permeation through iron, nickel, and heat resisting alloys at elevated temperatures

    International Nuclear Information System (INIS)

    Hydrogen permeabilities of several metals and alloys were measured over the temperature range of 200 - 10000C and some factors affecting the hydrogen permeability were discussed. Materials studied were iron, nickel, 80Ni-20Cr alloy, 50Fe-30Ni-20Cr alloy, HK 40, Incoloy 800, Hastelloy X, and Inconel 600. The hydrogen permeability of nickel was proportional to the square root of the pressure and inversely proportional to the membrane thickness. The activation energy and pre-exponential factor for the hydrogen permeation through these metals and alloys were derived from the temperature coefficient. The hydrogen permeability of nickel was larger than that of iron (γ), and the permeabilities of the heat resisting alloys were between those of nickel and iron (γ). There was a close correlation between the hydrogen permeability and nickel content in the alloys, that is, the permeability increased with the increase of the nickel content in the alloys. The formation of the oxide film on the alloy surface in wet hydrogen resulted in a remarkable reduction of the hydrogen permeability at elevated temperatures. (auth.)

  18. 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)

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. Polymer-Derived Ceramics as Innovative Oxidation Barrier Coatings for Mo-Si-B Alloys

    Science.gov (United States)

    Hasemann, Georg; Baumann, Torben; Dieck, Sebastian; Rannabauer, Stefan; Krüger, Manja

    2015-04-01

    A preceramic polymer precursor, perhydropolysilazane, is used to investigate its function as a new type of oxidation barrier coating on Mo-Si-B alloys. After dip-coating and pyrolysis at 1073 K (800 °C), dense and well-adhering SiON ceramic coatings could be achieved, which were investigated by SEM and cyclic oxidation tests at 1073 K and 1373 K (800 °C and 1100 °C). The coating is promising in reducing the mass loss during the initial stage of oxidation exposure at 1373 K (1100 °C) significantly.

  6. High-temperature microstructural characteristics of a novel biomedical titanium alloy

    International Nuclear Information System (INIS)

    In this study, the high-temperature microstructural characteristics of the Ti-5Al-1Sn-1Fe-1Cr (Ti-5111) alloy were determined by optical microscopy, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry. During solution treatment between 800 and 1000 oC, the phase transformation sequence of the alloy was found to be (α + β) → (α + α' + β) → (α + α' + α'' + residual β) → (α' + β). The residual β phase subsequently transforms to the α'' phase during quenching. The driving force for this transformation is the cooling rate. The martensite starting point (Ms) and β transus temperature of the Ti-5111 alloy are nearly 860 and 960 oC, respectively. These values are lower than those of the Ti-6Al-4V alloy. Moreover, it is believed that the concentration of Al in α' martensite plays a crucial role in the formation of the twin-type martensite.

  7. The susceptibility of Candu steam generator tubing alloys to IGA/IGSCC in acid sulphate environments

    International Nuclear Information System (INIS)

    Constant extension rate tests (CERT) were carried out to assess the susceptibility of CANDU steam generator (SG) tube materials to intergranular stress corrosion cracking (IGSCC) in acidified sulphate solutions calculated to exist in SG crevices following sulphuric acid and Lake Huron water ingress. The results indicate significant susceptibility of Alloy 600 tubing (i.e. Bruce A) to IGSCC following sulphuric acid ingress and some susceptibility to intergranular attack (IGA) following Lake Huron water ingress. Alloy 800 was slightly susceptible to IGA in sulphuric acid ingress crevice chemistries but not at all to Lake Huron water ingress crevice chemistry. Alloy 690 was not susceptible to IGSCC or IGA in any of the chemistries tested. Preliminary results suggest that lead contamination of 1000 ppm does not increase the susceptibility of any of the Alloys tested to IGSCC following sulphuric acid ingress. (authors). 3 figs., 2 tabs., 6 refs

  8. 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.

  9. Effect of High Temperature Aging on the Corrosion Resistance of Iron Based Amorphous Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Day, S D; Haslam, J J; Farmer, J C; Rebak, R B

    2007-08-10

    Iron-based amorphous alloys can be more resistant to corrosion than polycrystalline materials of similar compositions. However, when the amorphous alloys are exposed to high temperatures they may recrystallize (or devitrify) thus losing their resistance to corrosion. Four different types of amorphous alloys melt spun ribbon specimens were exposed to several temperatures for short periods of time. The resulting corrosion resistance was evaluated in seawater at 90 C and compared with the as-prepared ribbons. Results show that the amorphous alloys can be exposed to 600 C for 1-hr. without losing the corrosion resistance; however, when the ribbons were exposed at 800 C for 1-hr. their localized corrosion resistance decreased significantly.

  10. Study of the oxidation kinetics of the nickel-molybdenum alloy

    International Nuclear Information System (INIS)

    This research thesis reports the study of the oxidation of a nickel-molybdenum alloy in the high-nickel-content part of this alloy. After a bibliographical study on the both metals, the author proposes a physical model based on observed phenomena and based on experimental results. Based on a thermodynamic study, the author compares the stability of the different oxides which may be formed, and reports a prediction of oxides obtained on the alloy during oxidation. Qualitative and quantitative studies have been performed by scanning electron microscopy coupled with electronic microprobe analysis to investigate morphological characteristics on oxidation films. A kinetic study by thermogravimetry shows a decrease of the alloy oxidation rate with respect to that of pure nickel at temperatures lower than 800 degrees C. This result is interpreted by the intervention of two opposed diffusion phenomena which act against each other

  11. Brazing with plated alloys

    International Nuclear Information System (INIS)

    The use of braze alloy preforms on complex geometry components is at times a very difficult task requiring extensive handling of the parts or even tack welding of the preform to ensure that it is held in place. One method of overcoming these difficulties is the use of plated braze alloys (i.e., filler metals) applied directly to the braze region. Plating helps to avoid the potential for contamination resulting from handling and also ensures that the braze alloy is located properly. Examples are discussed in which an electroplated silver-copper alloy is used as an alternative to the BAg8 preforms and electroless nickel is used as a replacement for an amorphous Ni-P braze alloy foil. A toroidal cooling plate with helical flow channels was fabricated from oxygen-free high conductivity (OFHC) and brazed using the electroplated silver-copper alloy. The silver-copper braze alloy was applied to the copper substrate in a laminated fashion of alternating layers of silver and copper, which in combination approximated the eutectic composition (72% Ag-28% Cu by weight). Examination of the brazed assemblies indicated that in both cases the advantages of using plated braze alloys are numerous. These advantages include decreased labor, improved cleanliness and exactness of braze alloy placement. The primary disadvantage was an increased tendency for solidification defects presumably resulting from contaminants in the plating baths. This last observation is presently being examined in greater detail. The end results is that the assemblies brazed with the plated alloys were acceptable for the intended application and that the use of plating facilitated the successful assembly of these components

  12. High-Temperature Interaction Between Molten AlSr10 Alloy and Glass-Like Carbon Substrate

    Science.gov (United States)

    Siewiorek, A.; Sobczak, N.; Sobczak, J.; Kudyba, A.; Kozera, R.; Boczkowska, A.

    2016-03-01

    Wettability of glass-like carbon substrate (Cglc) by molten Al-10 wt.% Sr alloy (AlSr10) has been examined by a sessile drop method at 700-800 °C for 120 min under vacuum. Non-contact heating to the test temperature combined with the removal of oxide film from the alloy drop was done using capillary purification procedure by squeezing the liquid alloy from a capillary. The influence of the type of capillary on wetting behavior of AlSr10/Cglc couples was noticed. Molten AlSr10 alloy does not wet Cglc at about 700 °C forming the contact angles of 111° with graphite capillary and 141° with alumina capillary. At 800 °C with alumina capillary, non-wetting-to-wetting transition takes place resulting in a final contact angle of 70°. After testing at 800 °C, the AlSr10/Cglc interface was revealed at the test temperature directly in the vacuum chamber by the drop suction procedure. Structural characterization of the interfaces by scanning and transmission electron microscopy combined with energy-dispersive x-ray spectroscopy and by scanning probe microscopy combined with Auger electron spectrometry did not show any new phases formed with Sr. It suggests that the dominant role in wettability improvement by alloying Al with 10 wt.% Sr was related with significant lowering of the surface tension of liquid metal and adsorption of Sr at the interface.

  13. 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.

  14. 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

  15. 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

  16. Airports and Airfields, Published in unknown, 1:9600 (1in=800ft) scale, Stevens County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Airports and Airfields dataset, published at 1:9600 (1in=800ft) scale, was produced all or in part from Field Observation information as of unknown. Data by...

  17. Study of the susceptibility at SCC of Incoloy-800 in alkaline solution

    International Nuclear Information System (INIS)

    Incoloy-800, used to manufacture the steam generator tubes, has a good general corrosion resistance, but under certain conditions stress corrosion cracking (SCC) is observed. SCC can occur on both the primary and secondary sides of steam generator. Typical location for SCC is at dents, in the roll expansion regions of the tube and in areas containing concentrated impurities. Because under normal conditions the SCC mechanism requires a long time for initiation, it is necessary to use the accelerated corrosion tests to study the susceptibility of Incoloy-800 at caustic SCC. The mode of stressing of Incoloy-800 tubes used in our experiments was C-ring. To evaluate the stress and deformation induced in Incoloy-800 rings the ANSYS code was used. By using the cathodic zone of the potentiodynamic curves, the most important electrochemical parameters were calculated: the corrosion current (Icorr), the corrosion rate (vcorr) and the polarization resistance. The tested samples were examined by using the metallographic method. (author)

  18. 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...

  19. 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.

  20. 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.

  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. 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...

  3. ′ 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...

  4. 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)

  5. 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.

  6. 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.

  7. An Electromotive Force Measurement System for Alloy Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Changhu Xing; Colby Jensen; Heng Ban; Robert Mariani; J. Rory Kennedy

    2010-11-01

    The development of advanced nuclear fuels requires a better understanding of the transmutation and micro-structural evolution of the materials. Alloy fuels have the advantage of high thermal conductivity and improved characteristics in fuel-cladding chemical reaction. However, information on thermodynamic and thermophysical properties is limited. The objective of this project is to design and build an experimental system to measure the thermodynamic properties of solid materials from which the understanding of their phase change can be determined. The apparatus was used to measure the electromotive force (EMF) of several materials in order to calibrate and test the system. The EMF of chromel was measured from 100°C to 800°C and compared with theoretical values. Additionally, the EMF measurement of Ni-Fe alloy was performed and compared with the Ni-Fe phase diagram. The prototype system is to be modified eventually and used in a radioactive hot-cell in the future.

  8. Quantitative electron probe microanalysis investigation of the oxidation of high temperature alloys at low oxygen partial pressures

    International Nuclear Information System (INIS)

    Using electron probe microanalysis techniques, the oxidation of two high temperature alloys (alloy 617 and alloy 800 H) has been investigated. Specimens were exposed for up to 5000 h in a simulated methane reformer gas environment in the temperature range 800 to 9500C. Oxygen partial pressures were in the range 10-19 to 10-16 bar. In the investigation, particular attention was given to the determination of quantitative data for the oxide scales formed at the surface, the analysis of minor elements in the scale and the depletion effects in the matrix immediately below the scale. The oxide scale formed on alloy 800 H was found to comprise two layers, an outer layer containing Mn(1+x)Cr2(1-x)TixO4 (spinel) and MnTiO3 (Ilmenite type) and an inner layer of Cr2-yTiyO3 where 0.052-yTiyO3. Concentration profiles in the sub-surface regions for the constituent elements were measured and used to determine the mass flow at the surface in mg cm-2. The mass flow was then incorporated as a boundary condition in a diffusion program for calculation of the concentration profile. The program allowed derivation of the diffusion coefficients of Cr, Mn and Ti, and the values obtained were in good agreement with those published in the literature. It was found that the dissolution of chromium carbides in the near-surface regions caused by depletion of chromium to form the scale contributed up to 50% of the chromium consumed in oxidation in alloy 617. In alloy 800 H, the contribution was significantly lower. (orig.)

  9. 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.

  10. 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...

  11. 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...

  12. 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

  13. Novel high-strength ternary Zr–Al–Sn alloys with martensite structure for nuclear applications

    International Nuclear Information System (INIS)

    High strength is essential for the practical application of Zr alloys as structural materials. In this work, Zr–5Al–xSn (x = 2, 3, 4, 5 and 6) alloys have been designed and fabricated through arc melting in order to effectively improve the strength while retaining good ductility. Phase analysis results show that all the samples consist of single phase α-Zr. The variation trend of lattice constants as a function of Sn content has been analyzed. The microstructural analysis indicates that the Zr–5Al–xSn alloys mainly contain martensite structure. Mechanical tests show that these Zr–5Al–xSn alloys exhibit high compressive strength (1250–1450 MPa), high yield stress (800–1000 MPa), and favorable plastic strain of 18–23%. The fracture mode has been experimentally analyzed. Finally, both Zr–5Al–3Sn and Zr–5Al–5Sn are subjected to heat treatments for further study on the roles of Sn element and controlled heat treatment on the microstructure and mechanical properties of Zr alloys. Sn is found to promote the formation of ZrAl in the Zr–5Al–xSn alloys. Moreover, the martensite laths are observed to evolve into larger strip grains and fine equiaxed grains after heat treatment at 900 °C for 2 h. These factors strengthen the Zr–5Al–xSn alloys

  14. 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

  15. 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

  16. 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.

  17. Interdiffusion between Zr Diffusion Barrier and U-Mo Alloy

    International Nuclear Information System (INIS)

    U-Mo alloys are being developed as low enrichment uranium fuels under the Reduced Enrichment for Research and Test Reactor (RERTR) program. Significant reactions have been observed between U-Mo fuels and Al or Al alloy matrix. Refractory metal Zr has been proposed as barrier material to reduce the interactions. In order to investigate the compatibility and barrier effects between U-Mo alloy and Zr, solid-to-solid U-10wt.%Mo vs. Zr diffusion couples were assembled and annealed at 600, 700, 800, 900 and 1000 deg C for various times. The microstructures and concentration profiles due to interdiffusion and reactions were examined via scanning electron microscopy and electron probe microanalysis, respectively. Intermetallic phase Mo2Zr was found at the interface and its population increased when annealing temperature decreased. Diffusion paths were also plotted on the U-Mo-Zr ternary phase diagrams with good consistency. The growth rate of interdiffusion zone between U-10wt.%Mo and Zr was also calculated under the assumption of parabolic diffusion, and was determined to be about 103 times lower than the growth rate of diffusional interaction layer found in diffusion couples U-10wt.%Mo vs. Al or Al-Si alloy. Other desirable physical properties of Zr as barrier material, such as neutron adsorption rate, melting point and thermal conductivity are presented as supplementary information to demonstrate the great potential of Zr as the diffusion barrier for U-Mo fuel systems in RERTR.

  18. 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.

  19. 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

  20. Pareto-optimal alloys

    DEFF Research Database (Denmark)

    Bligaard, Thomas; Johannesson, Gisli Holmar; Ruban, Andrei; Skriver, Hans Lomholt; Jacobsen, Karsten Wedel; Nørskov, Jens Kehlet

    2003-01-01

    cost. In this letter we present a database consisting of the lattice parameters, bulk moduli, and heats of formation for over 64 000 ordered metallic alloys, which has been established by direct first-principles density-functional-theory calculations. Furthermore, we use a concept from economic theory......, the Pareto-optimal set, to determine optimal alloy solutions for the compromise between low compressibility, high stability, and cost....

  1. 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

  2. Fuel component of electricity generation cost for the BN-800 reactor with 800 MOX fuel and uranium oxide fuel, increased fuel burnup, and removal of radial breeding blanket

    International Nuclear Information System (INIS)

    There are two completed design concepts of NPP with BN-800 type reactors developed with due regard for enhanced safety requirements. They have been created for the 3rd unit of Beloyarsk NPP and for three units of South Ural NPP. Both concepts are proposed to use mixed oxide fuel (MOX) based on civil plutonium. At this moment economical estimations carried out for these projects need to be revised in connection with the changes of economical situation in Russia and the world nuclear market structure. It is also essential to take into account the existing problem of the excess ex-weapons plutonium utilization and the possibility of using this plutonium to fabricate MOX fuel for the BN-800 reactors. (authors)

  3. Anodic behavior of nickel alloys in media containing bicarbonate ions

    International Nuclear Information System (INIS)

    Alloy 22 has been designed to resist corrosion in oxidizing and reducing conditions. Thanks to these properties it is considered a possible candidate for the fabrication of containers of high-level radioactive waste. Since the containers provide services in natural environments characterized by multi-ionic solutions, it is estimated they could suffer three types of deterioration: general corrosion, localized corrosion (specifically crevice corrosion) and stress corrosion cracking (SCC). It has been confirmed that the presence of bicarbonate and chloride ions is required in order to produce cracking. It has also been determined that the susceptibility to SCC could be related to the occurrence of an anodic peak in the polarization curves in these media potentials below trans-passivity. The aim of this work is to study the anodic behavior of Alloy 22 in different media containing bicarbonate and chloride ions in various concentrations and temperatures and compare the results with other alloys containing nickel, and relate them to the susceptibility to stress corrosion cracking in a future job. Polarization curves were made on alloy 22 (Ni-Cr-Mo), 600 (Ni- Cr-Fe), 800h (Ni-Fe- Cr) and 201 (Ni commercially pure) in the following environments: 1.148 mol/L NaHCO3, 1.148 mol/L NaHCO3 + 1 mol/L NaCl, 1.148 mol/L NaHCO3 + 0.1 mol/L NaCl. The tests were performed at the following temperatures: 90°C, 75°C, 60°C and 25°C. It was found that alloy 22 has a current peak in the anodic domain at potentials below trans-passivity between 200 and 300 m VECS, when the test temperature was 90°C. The potential, at which this peak occurred, increased with decreasing temperature. Also there was a variation of the peak with the composition of the solution. When bicarbonate ions were added to a solution containing chloride ions, the peak potential shifted to higher current densities, depending on the concentration of added chloride ions. It was found that diminishing the content of

  4. Texture in low-alloyed uranium alloys

    International Nuclear Information System (INIS)

    The dependence of the preferred orientation of cast and heat-treated polycrystalline adjusted uranium and uranium -0.1 w/o chromium alloys on the production process was studied. The importance of obtaining material free of preferred orientation is explained, and a survey of the regular methods to determine preferred orientation is given. Dilatometry, tensile testing and x-ray diffraction were used to determine the extent of the directionality of these alloys. Data processing showed that these methods are insufficient in a case of a material without any plastic forming, because of unreproducibility of results. Two parameters are defined from the results of Schlz's method diffraction test. These parameters are shown theoretically and experimentally (by extreme-case samples) to give the deviation from isotropy. Application of these parameters to the examined samples showes that cast material has preferred orientation, though it is not systematic. This preferred orientation was reduced by adequate heat treatments

  5. WC-3015 alloy (high-temperature alloy)

    International Nuclear Information System (INIS)

    WC-3015 Nb alloy containing 28 to 30 Hf, 1 to 2 Zr, 13 to 16 W, 0 to 4 Ta, 0 to 5 Ti, 0.07 to 0.33 C, less than or equal to 0.02 N, less than or equal to 0.03 O, less than or equal to 0.001 H was developed for use at high temperature in oxidizing environments. Its composition can be tailored to meet specific requirements. When WC-3015 is exposed to O at elevated temperature, Hf and Nb oxidized preferentially and HfO2 dissolves in Nb2O5 to form 6HfO-Nb2O5. This complex oxide has a tight cubic lattice which resists the diffusion of O into the substrate. During 24-h exposure to air at 24000F, the alloy oxidizes to a depth of approximately 0.035 in. with a surface recession of 0 to 0.004 in. Oxidation resistance of WC-3015 welds and base material can be further enhanced greatly by applying silicide coatings. WC-3015 alloy can be machined by conventional and electrical-discharge methods. It can be hot worked readily by extrusion, forging or rolling. Cold working can be used at room or elevated temperature. It can be welded by the electron-beam or Tig processes. Physical constants, typical mechanical properties at 75 to 24000F, and effects of composition and heat treatment on tensile and stress-rupture properties of the alloy are tabulated

  6. 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.

  7. 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.

  8. 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 ...

  9. Correlation between diffusion barriers and alloying energy in binary alloys

    DEFF Research Database (Denmark)

    Vej-Hansen, Ulrik Grønbjerg; Rossmeisl, Jan; Stephens, Ifan; Schiøtz, Jakob

    2016-01-01

    In this paper, we explore the notion that a negative alloying energy may act as a descriptor for long term stability of Pt-alloys as cathode catalysts in low temperature fuel cells.......In this paper, we explore the notion that a negative alloying energy may act as a descriptor for long term stability of Pt-alloys as cathode catalysts in low temperature fuel cells....

  10. 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.

  11. 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)

  12. Selective de-alloying of NiTi by oxochloridation

    International Nuclear Information System (INIS)

    The systematic modification of a nickel-titanium-alloy by annealing in a complex gas atmosphere was investigated. A mixture of HCl and H2O in inert argon was chosen. The reaction kinetics was investigated at 600 deg. C, 700 deg. C and 800 deg. C. The reaction kinetics displayed a significant dependence on the temperature. It was monitored by means of a thermogravimetric balance that showed a quasi-parabolic scale growth at 600 deg. C, a paralinear or so called Tedmon kinetic at 700 deg. C with a distinct weight maximum after about 35 h, and finally a linear evaporation kinetic at 800 deg. C. This behaviour is attributed to the concurrent reactions of oxidation, chloridation and evaporation of corrosion products. The kinetics of these reactions is different for the two alloying elements and with respect to the equiatomic composition they are coupled to each other. Cross sections prove that a stochiometric titanium depletion is achieved leading to the formation of a Ni3Ti layer (d = 50 μm) which is in turn covered by a pure titanium oxide layer (d = 40 μm). The applicability of this technique for tailored surfaces with a high degree of biocompatibility is discussed

  13. 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...

  14. 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...

  15. 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.

  16. 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.

  17. Comparison of high order modes damping techniques for 800 MHz single cell superconducting cavities

    CERN Document Server

    Shashkov, Ya V; Zobov, M M

    2014-01-01

    Currently, applications of 800 MHz harmonic cavities in both bunch lengthening and shortening regimes are under consideration and discussion in the framework of the High Luminosity LHC project. In this paper we study electromagnetic characteristics of high order modes (HOM) for a single cell 800 MHz superconducting cavity and arrays of such cavities connected by drifts tubes. Different techniques for the HOM damping such as beam pipe grooves, coaxial-notch loads, fluted beam pipes etc. are investigated and compared. The influence of the sizes and geometry of the drift tubes on the HOM damping is analyzed.

  18. 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.

  19. Hydrogen in titanium alloys

    International Nuclear Information System (INIS)

    The titanium alloys that offer properties worthy of consideration for fusion reactors are Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo-Si (Ti-6242S) and Ti-5Al-6Sn-2Zr-1Mo-Si (Ti-5621S). The Ti-6242S and Ti-5621S are being considered because of their high creep resistance at elevated temperatures of 5000C. Also, irradiation tests on these alloys have shown irradiation creep properties comparable to 20% cold worked 316 stainless steel. These alloys would be susceptible to slow strain rate embrittlement if sufficient hydrogen concentrations are obtained. Concentrations greater than 250 to 500 wppm hydrogen and temperatures lower than 100 to 1500C are approximate threshold conditions for detrimental effects on tensile properties. Indications are that at the elevated temperature - low hydrogen pressure conditions of the reactors, there would be negligible hydrogen embrittlement

  20. Welding of refractory alloys

    International Nuclear Information System (INIS)

    This review primarily summarizes welding evaluations supported by NASA-Lewis Research Center in the 1960s. A literature search run in preparation for this review indicates that more recent work is modest by comparison. Hence, this review restates these accomplishments briefly and addresses opportunities which have evolved in welding technology (such as lasers) in the intervening decade. Emphasis in this review is given to tantalum- and niobium-base alloys. Considerable work was also done to assure that a consistent comparison was made with tungsten. A wide variety of candidate alloys derived primarily from developments directed at aircraft propulsion applications were available. Early efforts by NASA were directed at screening studies to select promising structural alloys for the space power application. This objective required fine tuning of welding procedures, e.g., the demonstration of stringent standards for control of welding atmosphere to assure good corrosion resistance in liquid alkali metals. 16 figures, 6 tables

  1. 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.

  2. 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.

  3. Creep Rupture Properties for Base and Weld Metals of Alloy 617

    International Nuclear Information System (INIS)

    The allowable deformation in the welds is also restricted to half the deformation permitted for the base metal, since the ductility of the welds at elevated temperatures is generally low. For a design use, the data of the tensile and creep properties for Alloy 617 WM should be sufficiently provided, and in particular, to develop a design code of Alloy 617 WM. However, the data for the WM are very rare and limited until now, although the data for the BM are available in the ASME draft code case, which was suspended at the end of the 1980s owing to a lack of support and interes. In this report, the creep data for Alloy 617 WM, which was fabricated by a gas tungsten arc welding (GTAW) procedure, were obtained by a series of creep tests at 800 .deg. C, and the creep properties of the WM were compared with those of the BM. The high-temperature creep properties for Alloy 617 WM, fabricated by a gas tungsten arc welding (GTAW) procedure, were investigated by a series of creep tests with different stress levels at 800 .deg. C, and the creep test data for the WM were compared with those of the BM. From the results, it was found that the WM had a slightly longer creep rupture life and lower creep rate than the BM, and a particularly lower rupture elongation. The lower creep rate in the WM was due to the lower rupture elongation than the BM

  4. Microstructural changes in Nd-Fe-B magnet alloys during HDDR phenomena

    International Nuclear Information System (INIS)

    Microstructural changes in Nd-Fe-B alloys during the hydrogenation, disproportion, and recombination (HDDR) phenomena were studied by XRD and TEM. These phenomena are caused by a heat treatment in hydrogen (H-treatment), in which disproportion occurs, and a subsequent heat treatment in vacuum (V-treatment), in which the recombination reaction occurs. The disproportionated mixture is formed of submicron sized colonies, which consist of Nd H2 rods embedded in an α-Fe matrix, at the first stage of the disproportion reaction. Some relationship in crystallographic orientation was observed among the Nd H2, α-Fe, and the undecomposed Nd2 Fe14 B phases. H-treatment at higher temperatures causes the grain growth of the disproportionated phases, but the relationship in crystallographic orientation remains between the Nd H2 and α-Fe phases. The recombined Nd2 Fe14 B grains in the alloys V-treated at temperatures higher than 800 deg C, exhibit the same texture as the original, untreated alloys, and this grain alignment appears to begin as the recombination occurs. The alloys V-treated at temperatures lower than 800 de C show isotropic characteristics. (author)

  5. 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.

  6. 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...

  7. 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.

  8. Hierarchical nanoporous platinum-copper alloy for simultaneous electrochemical determination of ascorbic acid, dopamine, and uric acid

    International Nuclear Information System (INIS)

    A hierarchical nanoporous PtCu alloy was fabricated by two-step dealloying of a PtCuAl precursor alloy followed by annealing. The new alloy possesses interconnected hierarchical network architecture with bimodal distributions of ligaments and pores. It exhibits high electrochemical activity towards the oxidation of ascorbic acid (AA), dopamine (DA), and uric acid (UA) at working potentials of 0.32, 0.47 and 0.61 V (vs. a mercury sulfate reference electrode), respectively. The new alloy was placed on a glassy carbon electrode and then displayed a wide linear response to AA, DA, and UA in the concentration ranges from 25 to 800 μM, 4 to 20 μM, and 10 to 70 μM, respectively. The lower detection limits are 17.5 μM, 2.8 µM and 5.7 μM at an S/N ratio of 3. (author)

  9. 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

  10. 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).

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. Shape memory effect alloys

    International Nuclear Information System (INIS)

    Although the pseudo- or super-elasticity phenomena and the shape memory effect were known since the 1940's, the enormous curiosity and the great interest to their practical applications emerged with the development of the NITINOL alloy (Nickel-Titanium Naval Ordance Laboratory) by the NASA during the 1960's. This fact marked the appearance of a new class of materials, popularly known as shape memory effect alloys (SMEA). The objective of this work is to present a state-of-the-art of the development and applications for the SMEA. (E.O.)

  17. Soldering of aluminium alloys

    International Nuclear Information System (INIS)

    A literature survey about soldering in general and aluminium alloys soldering in particular is presented. The existing methods of soldering aluminium alloys are described. These include soldering with flux, soldering after preliminary plating, vacuum brazipressure and temperature (NTP), sample age calculation based on 14C half life of 5570 and 5730 years, age correction for NTP, dendrochronological corrections and the relative radiocarbon concentration. All results are given with one standard deviation. Input data test (Chauvenet's criterion), gas purity test, standard deviation test and test of the data processor are also included in the program. (author)

  18. 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.

  19. Deformation behaviour and new constitutive equation utilising the grain size of commercial TC6 titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, M.Q.; Xiong, A.M. [Northwestern Polytechnical Univ., Coll. of Materials Science and Engineering, Xi' an (China); Wang, H.R.; Su, S.B.; Shen, L.C. [Xi' an Aero-Engine Co. Ltd., Xi' an (China)

    2004-10-01

    Isothermal compression tests on a commercial TC6 titanium alloy have been conducted at deformation temperatures of about 800 - 1040 deg C, strain rates of 0.001 - 50 s{sup -1} and height reductions of 30 - 50%. The microstructural evolution is represented through the measured grain size of the prior {alpha}-phase. Meanwhile, a new constitutive equation, which includes the grain size, is established for high temperature deformation behaviour. The procedure required to formulate a constitutive equation from the experimental results is presented. The constitutive equation to model the behaviour of the TC6 titanium alloy during high temperature deformation is validated and its formulation is presented. The results show that the present equation is satisfactory for describing the behaviour of the TC6 titanium alloy during high temperature deformation. The maximum difference between the calculated and the experimental results is less than 15%. (Author)

  20. 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.

  1. On the discontinuous precipitation reaction and solute redistribution in a Cu-15%Ni-8%Sn alloy

    International Nuclear Information System (INIS)

    Optical and transmission electron microscopy studies have been undertaken in order to clarify some morphological aspects of the discontinuous precipitation (DP) reaction in a Cu-15Ni-8Sn (wt.%) alloy in the temperature range 800-950 K. The DP reaction proceeds in the ternary Cu-Ni-Sn system relatively fast (in binary Cu-Ni alloy is not present) with typical morphological features like change of growth direction, appearance and disappearance of solute-rich γ lamellae. A fine continuous precipitation of single Ni and Sn-rich phase was also evidenced within the solute-depleted α lamellae. An energy-dispersive X-ray analysis showed the level of partitioning of the alloying elements. Most of the Ni and Sn is located in the γ lamellae. However, the formula of the γ lamellae is still close to (Cu3Sn), which indicates that some Cu atoms are replaced by Ni

  2. 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.

  3. 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.

  4. Operating limits of AL-alloyed high-low junctions for BSF solar cells

    Science.gov (United States)

    del Alamo, J.; Eguren, J.; Luque, A.

    1981-05-01

    Experimental estimations of the effective surface recombination velocity of the high-low junction and of the base diffusion length are carried out for Al-alloyed n(plus)pp(plus) bifacial cells and the results are presented in form of histograms. These results agree with calculated values of the effective surface recombination velocity when the characteristics of the recrystallized Si layer and heavy doping effects are taken into account. It is concluded that thick Al layers and high alloying temperatures (over 800 C) are necessary to obtain low values of the velocity. This conclusion agrees with experimental results of other authors. Recommendations to avoid diffusion length degradation are given and the operating limits of the Al alloying technology are discussed.

  5. 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

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

    International Nuclear Information System (INIS)

    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−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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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。

  12. 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.

  13. 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.

  14. Pemilihan Bahan Alloy Untuk Konstruksi Gigitiruan

    OpenAIRE

    Medila Dahlan

    2008-01-01

    Pada kedokteran gigi bahan alloy sangat banyak digunakan dalam segala bidang. Dalam pembuatan konstruksi gigitiman biasanya digunakan alloy emas, alloy kobalt kromium, alloy nikei kromium dan alloy stainless steel sebagai komponen gigitiman kerangka logam serta pembuatan mahkota dan jembatan. Pemilihan bahan alloy dapat dilakukan berdasarkan sifat yang dimiiiki oleh masing-masing bahan alloy sehingga akan didapat hasil konstmksi gigitiruan yang memuaskan. Pada pemakaiannya didaiam mulut...

  15. Hydrogen embrittlement of vanadium alloys

    International Nuclear Information System (INIS)

    The mechanical properties of several vanadium alloys were measured with the hydrogen concentration high up to 113 mg/kg. The results showed that the alloys with low mechanical strength had better properties against hydrogen embrittlement. Oxygen in the alloy, especially that in the alloys with high strength, could enhance the hydrogen embrittlement. Mechanism analysis was given to show that the brittle fracture was mainly caused by intergranular failure. The effects of oxygen concentration and the strength of the alloy were both resulted from their contributions to the grain strength and the grain boundary strength

  16. 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)

  17. 31 CFR 800.504 - Determination not to undertake an investigation.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Determination not to undertake an... Determination not to undertake an investigation. If the Committee determines, during the review period described in § 800.502, not to undertake an investigation of a notified covered transaction, action...

  18. 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...

  19. 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...

  20. New design of a high-power femtosecond 800-nm laser

    International Nuclear Information System (INIS)

    A new simple design of a femtosecond laser is proposed, which consists of a 1550-nm erbium-doped fibre laser, a fibre stretcher, a BBO crystal parametric amplifier converting the input radiation to the 800-nm radiation, a Ti:sapphire or a BBO amplifier, and a diffraction grating compressor. (lasers)

  1. Stellar Systems Inc. Series 800/5000 E-Field sensor evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Follis, R.L.

    1990-08-01

    This report concerns the evaluation of the Stellar Systems Inc. E-Field intrusion detection system Series 800 control unit and the 5000 Series hardware components. Included are functional descriptions, installation procedures, testing procedures, and testing/operational results. 35 figs.

  2. 34 CFR 85.800 - What are the causes for debarment?

    Science.gov (United States)

    2010-07-01

    ... procurement debarment by any Federal agency taken pursuant to 48 CFR part 9, subpart 9.4, before August 25... present responsibility. Authority: E.O. 12549 (3 CFR, 1986 Comp., p. 189); E.O 12689 (3 CFR, 1989 Comp., p... 34 Education 1 2010-07-01 2010-07-01 false What are the causes for debarment? 85.800 Section...

  3. 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...

  4. 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

  5. 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

  6. 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...

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

    Science.gov (United States)

    2010-10-29

    ... HUMAN SERVICES Food and Drug Administration Draft Compliance Policy Guide Sec. 690.800 Salmonella in...) 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...

  8. 40Ca(p,d)39Ca reaction in 50-800 MeV region

    International Nuclear Information System (INIS)

    Spectra of 40Ca(p,d)39Ca reactions at several tens MeV to 800 MeV are compared and the possibility of the classical nuclear spectroscopy with transfer reactions in intermediate energy region is discussed. (author)

  9. 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...

  10. 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

  11. 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

  12. Ferromagnetic bulk glassy alloys

    International Nuclear Information System (INIS)

    This paper deals with the review on the formation, thermal stability and magnetic properties of the Fe-based bulk glassy alloys in as-cast bulk and melt-spun ribbon forms. A large supercooled liquid region over 50 K before crystallization was obtained in Fe-(Al, Ga)-(P, C, B, Si), Fe-(Cr, Mo, Nb)-(Al, Ga)-(P, C, B) and (Fe, Co, Ni)-Zr-M-B (M=Ti, Hf, V, Nb, Ta, Cr, Mo and W) systems and bulk glassy alloys were produced in a thickness range below 2 mm for the Fe-(Al, Ga)-(P, C, B, Si) system and 6 mm for the Fe-Co-(Zr, Nb, Ta)-(Mo, W)-B system by copper-mold casting. The ring-shaped glassy Fe-(Al, Ga)-(P, C, B, Si) alloys exhibit much better soft magnetic properties as compared with the ring-shaped alloy made from the melt-spun ribbon because of the formation of the unique domain structure. The good combination of high glass-forming ability and good soft magnetic properties indicates the possibility of future development as a new bulk glassy magnetic material

  13. Shape Memory Alloy Actuator

    Science.gov (United States)

    Baumbick, Robert J. (Inventor)

    2002-01-01

    The present invention discloses and teaches a unique, remote optically controlled micro actuator particularly suitable for aerospace vehicle applications wherein hot gas, or in the alternative optical energy, is employed as the medium by which shape memory alloy elements are activated. In gas turbine powered aircraft the source of the hot gas may be the turbine engine compressor or turbine sections.

  14. 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...

  15. 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.)

  16. Abrasivity of Yttria Tetragonal Zirconia Polycrystal (Y-TZP) to dental enamel in comparison to noble white high palladium alloy

    OpenAIRE

    Caruana, K; Whilte, AJ; Bubb, NL; Brunton, PA

    2015-01-01

    Objectives: To test the wear of enamel against Yttria Tetragonal Zirconia Polycrystals (Y-TZP) in comparison to the wear of enamel against a noble white high Palladium alloy. Methods: A total of 20 specimens were used, 10 of Y-TZP and 10 of High Palladium alloy, both were subjected to 202,800 contacts against an enamel rod 2x2 mm in cross section under a mean load of 475.04g leading to a mean force of 4.66 N in a Wilson Wear Machine. The specimens were kept in Dulbecco’s phosphate buffered sa...

  17. High-temperature interaction of fuel rod cladding material (Zr1%Nb alloy) with oxygen-containing mediums

    International Nuclear Information System (INIS)

    The experimental data on kinetics of Zr1%Nb alloy oxidation in steam at atmospheric pressure in the temperature range 550 to 1600 deg. C are presented. The effect of fuel rod claddings deformation on zirconium alloy interaction with steam is shown. The estimates of influence of the additives of air, nitrogen and hydrogen in mixtures with steam at atmospheric pressure on kinetics of steam/zirconium reaction in the temperature range 800 to 1200 deg. C are presented. The correlations for determination of weight gain with indication of area of applicability in space of parameters (temperature, time, deformation, pressure) are shown. (author). 10 refs, 10 figs

  18. 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.

  19. High Temperature Internal Oxidation Behavior of Iron Based Alloys

    International Nuclear Information System (INIS)

    A study of growth kinetics and microstructure of internal oxides in the iron-base alloys was carried out by an optical microscope and a scanning electron microscope, so that the growth mechanisms of the oxide precipitates in the internal oxidation zone could be understood in detail. Iron-based alloys, Fe-1%Al, Fe-1%Al-1%Hf, Fe-1%Cr, Fe-1%Cr-1%Hf and Fe-2%Hf, were oxidized in a sealed quartz tube containing Fe/FeO powder mixtures which maintained the oxygen partial pressure at the FeO decomposition pressure at 800 .deg. C for the various time periods to 121 hours. Results show that the growth rate of the oxide precipitates in the internal oxidation zone is controlled by the diffusion of oxygen. The variation of the solute element and the addition of Hf in the iron-base alloys led to a change in the depth of internal oxidation zone and in the oxide morphology. The internal precipitate adopted the form of continuous needles or feathers for the Fe-Al system, whereas that in the Fe-Cr and Fe-2%Hf systems adapted the form of discontinuous crystallites, that is, spheres or polyhedral crystallites. The mechanism of this morphological evolution was explained in detail

  20. 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.

  1. Anelastic relaxation caused by interstitial atoms in β-type sintered Ti-Nb alloys

    International Nuclear Information System (INIS)

    Highlights: → In this study, the internal friction of the sintered β-type Ti-Nb alloys is measured using a dynamic mechanical analysis (DMA) Q800 from TA Instruments in single cantilever mode. The effects of heat treatment and compositions on the internal friction behavior of Ti-Nb alloys were investigated and discussed. The internal friction peak height is determined by the stability and amount of β phase. The peak height presents a maximum in the vicinity of 35 wt.% Nb for the quenched alloys, resulting from the variation of the stability and amount of βM with Nb content. In as-sintered alloys, the height of the peak increases monotonously with increasing Nb content due to the increase of the amount of βS. It has been suggested that the internal friction peak is related to oxygen jumps in lattice and the interactions of oxygen-substitute atoms in βM for the water-quenched alloys and in βS phase for the as-sintered alloys. - Abstract: The internal friction behavior of Ti-Nb alloys is investigated using a dynamic mechanical analysis (DMA) Q800 from TA Instruments in single cantilever mode. Relaxational internal friction peaks are found on the internal friction temperature dependent curves in the sintered alloys. The peak does not appear in the sintered Ti-Nb alloys with low Nb content. The water-quenched Ti-35.4 (wt.%) Nb alloy has much higher the internal friction peak than the as-sintered alloy with identical compositions. Therefore, the peak height depends on heat treatment and Nb content. It is deduced that the peak is linked to the β phase of Ti-Nb alloys and that the peak height is determined by the stability and amount of the β phase. When the stability of the β phase is decreased, the peak height is increased. The increase in the amount of β phase results in the increase of the peak height. The β phase in the quenched Ti-35.4Nb specimen is metastable β phase (βM), which can be transformed into the stable α and βS by aging. The β phase in

  2. 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.

  3. Operating experience of BN-600 fast neutron reactor and BN-800 reactor design

    International Nuclear Information System (INIS)

    Full text: Experience gained in Russia (USSR) in R and D work in the area of sodium cooled fast reactors in the period of 1950-1970s has been used in the design of NPP with the BN-600 reactor. Since its start-up in 1980, BN-600 reactor has demonstrated operating characteristics, which are unique for this nuclear technology. Average load factor value for 23 years of operation is near 74%, its values in 2002 and 2003 being respectively 77.35% and 75.7%. Release of inert radioactive gases is within 0.3% of reference value, while average collective dose rate of personnel is about 0.3 man. Sv per year. In the course of operation of NPP with the BN-600 reactor, effectiveness of steam generator protection system was demonstrated in 12 cases of small and large water-into-sodium leaks. Besides, unique experience was gained in confining either radioactive and non-radioactive sodium fires in case of sodium leaks from the circuits. Radioactive sodium leak from the primary auxiliary circuit occurred in December 1994 is a typical example. Total amount of sodium released from the circuit was about 1000 kg, and protection system was capable of confining sodium ignition nucleation site and limiting radioactivity release to the atmosphere by 10 Ci value. This release has had almost zero effect on radiological conditions of the NPP controlled area. BN-800 reactor design is the next stage of development of sodium cooled fast reactor technology. Fourth power unit with the BN-800 reactor is now under construction on Beloyarskaya NPP site. Innovative design approaches have been used in the BN-800 reactor in order to further improve safety of fast reactors with sodium coolant. Among these innovations are as follows: Additional 'passive' safety system using three absorber rods hydraulically suspended by the sodium flow; Passive decay heat removal system using sodium-air heat exchangers; Device for collection and retaining of the core debris in case of its disruption under conditions of

  4. Interphase thermodynamic bond in heterogeneous alloys: effects on alloy properties

    International Nuclear Information System (INIS)

    Inconsistency between a conventional thermodynamic description of alloys as a mechanical mixture of phases and a real alloys state as a common thermodynamic system in which there is a complicated physical-chemical phases interaction has been considered. It is supposed that in heterogeneous alloys (eutectic ones, for instance), so called interphase thermodynamic bond can become apparent due to a partial electron levels splitting under phase interaction. Thermodynamic description of phase equilibrium in alloys is proposed taking into account a thermodynamic bond for the system with phase diagram of eutectic type, and methods of the value of this bond estimation are presented. Experimental evidence (Al-Cu-Si, Al-Si-Mg-Cu, U-Mo + Al) of the effect of interphase thermodynamic bond on temperature and enthalpy of melting of alloys are produced as well as possibility of its effects on alloys electrical conduction, strength, heat and corrosion resistance is substantiated theoretically

  5. Fe-30Ni-5NiO alloy as inert anode for low-temperature aluminum electrolysis

    Science.gov (United States)

    Zhu, Yuping; He, Yedong; Wang, Deren

    2011-05-01

    Fe-30Ni-5NiO alloy anodes were prepared by a spark plasma sintering process for aluminum electrolysis. NiO nano-particles with the size of ˜20 nm were dispersed in the anodes. The oxidation behaviors of the anodes were investigated at 800°C and 850°C, respectively. The electrolysis corrosion behaviors were tested in a cryolite-alumina electrolyte at a low temperature of 800°C with anodic current densities of ˜0.5 A/cm2. The results indicated that the oxidation kinetic of the anodes followed a parabolic law. A continuous Fe2O3 film selectively formed on the surface of the anode during the electrolysis process. A semi-continuous Al2O3 layer was observed at oxide film/alloy interface, probably caused by an in-situ chemical dissolution process.

  6. Formation and stability of Fe-rich precipitates in dilute Zr(Fe) single-crystal alloys

    International Nuclear Information System (INIS)

    The formation and stability of Fe-rich precipitates in two α-Zr(Fe) single-crystal alloys with nominal compositions (I, 50 ppma Fe, and II, 650 ppma Fe) have been investigated (the maximum solid solubility of Fe in α-Zr is 180 ppma - 800 C). Optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been used to examine the characteristics of Fe-rich precipitates. SEM and TEM micrographs show that in as-grown alloy II, Zr2Fe precipitates are located at 'stringers'. Precipitates were not observed in as-grown alloy I. During annealing, below the solvus, Fe diffuses to the surfaces to form Zr3Fe precipitates in both alloys. The precipitates on the surfaces of alloy I tend to be star-like (0001) or pyramidal (1010), and their distribution is heterogeneous. Dissolution of Zr3Fe surface precipitates of alloy I (annealing above the solvus) leaves precipitate-like features on the surfaces. Zr2Fe precipitates in as-grown alloy II can be dissolved only by β-phase annealing. (Author) 8 figs., 18 refs

  7. 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.

  8. Effect of hot rolling on the microstructure and mechanical properties of Ti3Al based dual phase alloys

    International Nuclear Information System (INIS)

    Development of α2-Ti3Al based dual phase alloys have shown some promising potentials in property improvement by introducing Ti5Si3 silicide phase into the matrix via Si alloying. However, the presence of coarse network of Ti5Si3 phase formed by eutectic reaction in the as-cast state also embrittles the alloy. Both hot rolling and powder metallurgy are considered to be the possible ways to refine the Ti5Si3 phase in the matrix. Two Ti-Al-Si-Nb alloys whose Si contents are 2 and 5 at.% respectively were arc melted into ingots and then hot rolled to sheets in this investigation. Optical metallographic examination correlates the microstructures of the as-cast and as-rolled alloys with the different rolling amounts, showing that the coarse silicide network is broken into small particles after hot rolling. Mechanical property testing from room temperature to 800 C indicates that the strength and plastic elongation of the hot-rolled alloys are much higher than those of the as-cast ones. The data obtained in this investigation are comparable with those obtained in the P/M processed specimens. Fracture surfaces of the alloys are also examined

  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. 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.

  11. 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.).

  12. Inclusive charm cross sections in 800 GeV/c p-p interactions

    International Nuclear Information System (INIS)

    We report a measurement of the inclusive D/anti D production cross section in 800 GeV/c proton-proton interactions. The experiment used the high resolution bubble chamber LEBC exposed to an 800 GeV/c proton beam at the Fermilab MPS. We obtain σ(D/anti D)=59±19μb (statistical errors), having analysed 25% of the total data sample. Comparison with 400 GeV/c pp data obtained with LEBC at CERN shows a D/anti D cross section increase by a factor of 1.7±0.6. This is in good agreement with fusion model calculations. (orig.)

  13. THE EFFECT OF 800 0C ON BOND STRENGTH OF CONCRETE WITH MINERAL ADMIXTURE

    Directory of Open Access Journals (Sweden)

    Ahmet COŞKUN

    2007-03-01

    Full Text Available The effect of high temperature (800 0C on the bond strength between concrete and rebar was investigated. In addition to concrete mixture with only portland cement, concrete mixtures with 10% silica fume and 15 % fly ash replacing cement by weight was prepared. Maximum aggregate size is as 16 mm. The 150×150×150 mm cube specimens were prepared for compressive strength and the 100×200 mm cylinder specimens were prepared for bond strength. The specimens were cured in air for 270 days after curing in water 20±2 °C for 28 days. After being heated to temperatures of 800 ºC, compressive strength and bond strength of concrete were tested. The results showed that specimens with silica fume always gave the highest values followed by those as specimens with fly ash and specimens without mineral admixtures irrespective of type and age of concrete and test methods.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. Investigation of the 800 keV Peak in the Gamma Spectrum of Swedish Laplanders

    International Nuclear Information System (INIS)

    The gamma spectrum of the body radioactivity in reindeer raising Laplanders has shown a peak at 800 keV, which has not been discussed before in connection with whole body counting. We present here an investigation that was made to be able to identify the isotope. The result is that the peak comes from cesium 134. The possibility to find cesium 134 in fallout is discussed

  19. 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)

  20. Do Switching Costs Make Markets More or Less Competitive?: The Case of 800-Number Portability

    OpenAIRE

    2001-01-01

    Do switching costs reduce or intensify price competition in markets where firms charge the same price to old and new consumers? Theoretically, the answer could be either "yes" or "no," due to two opposing incentives in firms' pricing decisions. The firm would like to charge a higher price to previous purchasers who are "locked-in" and a lower price to unattached consumers who offer higher future profitability. I demonstrate this ambiguity in an infinite-horizon theoretical model. 800- (toll-f...

  1. 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...

  2. 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.

  3. Electromagnetic calculations for an improved design of the Milan K800 cyclotron RF cavities

    International Nuclear Information System (INIS)

    This paper presents the results of the extensive calculations carried out for the optimization of the Milan K800 cyclotron RF cavities, using a special version of the computer code SUPERFISH. A simulation, via a cylindrical symmetric model, of the cavity dee-liner region, has been developed. The procedure followed and its theoretical justification are sketched. Some new tools, useful for the design of the coaxial type cavities, are also presented. (author)

  4. 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

  5. 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.

  6. 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...

  7. 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...... suggest that the interplay between obliquity and precession accounts for the variable intensity of interglacial periods in ice core records. Udgivelsesdato: 10.08...

  8. 75 FR 45130 - Draft Compliance Policy Guide Sec. 690.800 Salmonella

    Science.gov (United States)

    2010-08-02

    ...The Food and Drug Administration (FDA) is announcing the availability of a draft guidance for FDA staff entitled ``Compliance Policy Guide Sec. 690.800 Salmonella in Animal Feed'' (the draft CPG). The draft CPG, when finalized, is intended to provide guidance for FDA staff on regulatory policy relating to animal feed or feed ingredients that come in direct contact with humans, such as pet food......

  9. Research of Zlin Z42 engine´s operation by EDM-800 monitoring system

    OpenAIRE

    Maria MRAZOVA

    2015-01-01

    The purpose of this paper is based on the analysis of the M137 engine performance by the EDM- 800 monitoring system that is also mounted on Zlin Z42 aircraft in operation of Air Training and Education Centre of the University of Zilina. This research consists of measurements based on the comparison and analysis of the engine parameters where its performance was simulated under various temperature conditions. Measured parameters are monitored during these flight regimes – take off, climb, cru...

  10. 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.

  11. 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

  12. 21 CFR 800.20 - Patient examination gloves and surgeons' gloves; sample plans and test method for leakage defects...

    Science.gov (United States)

    2010-04-01

    ...; sample plans and test method for leakage defects; adulteration. 800.20 Section 800.20 Food and Drugs FOOD... plans and test method for leakage defects; adulteration. (a) Purpose. The prevalence of human... adulteration for patient examination and surgeons' gloves as a means of assuring safe and effective devices....

  13. 30 CFR 903.800 - Bond and insurance requirements for surface coal mining and reclamation operations under...

    Science.gov (United States)

    2010-07-01

    ... Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE ARIZONA § 903.800 Bond and insurance requirements for surface coal mining and reclamation operations under regulatory programs. (a) Part 800 of...

  14. 30 CFR 905.800 - Bond and insurance requirements for surface coal mining and reclamation operations under...

    Science.gov (United States)

    2010-07-01

    ... Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE CALIFORNIA § 905.800 Bond and insurance requirements for surface coal mining and reclamation operations under regulatory programs. (a) Part 800 of...

  15. 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...

  16. 47 CFR 22.970 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone...

    Science.gov (United States)

    2010-10-01

    .... Except as provided in 47 CFR 90.617(k), unacceptable interference to non-cellular part 90 licensees in...-cellular 800 MHz licensees from cellular radiotelephone or part 90-800 MHz cellular systems. 22.970 Section... MOBILE SERVICES Cellular Radiotelephone Service § 22.970 Unacceptable interference to part 90...

  17. 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...

  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. 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.

  20. 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.

  1. [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

  2. 1300°F 800 MWe USC CFB Boiler Design Study

    Science.gov (United States)

    Robertson, Archie; Goidich, Steve; Fan, Zhen

    Concern about air emissions and the effect on global warming is one of the key factors for developing and implementing new advanced energy production solutions today. One state-of-the-art solution is circulating fluidized bed (CFB) combustion technology combined with a high efficiency once-through steam cycle. Due to this extremely high efficiency, the proven CFB technology offers a good solution for CO2 reduction. Its excellent fuel flexibility further reduces CO2 emissions by co-firing coal with biomass. Development work is under way to offer CFB technology up to 800MWe capacities with ultra-supercritical (USC) steam parameters. In 2009 a 460MWe once-through supercritical (OTSC) CFB boiler designed and constructed by Foster Wheeler will start up. However, scaling up the technology further to 600-800MWe with net efficiency of 45-50% is needed to meet the future requirements of utility operators. To support the move to these larger sizes, an 800MWe CFB boiler conceptual design study was conducted and is reported on herein. The use of USC conditions (˜11 00°F steam) was studied and then the changes, that would enable the unit to generate 1300°F steam, were identified. The study has shown that by using INTREX™ heat exchangers in a unique internal-external solids circulation arrangement, Foster Wheeler's CFB boiler configuration can easily accommodate 1300°F steam and will not require a major increase in heat transfer surface areas.

  3. 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

  4. 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)

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

    International Nuclear Information System (INIS)

    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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Thermodynamic Database for Zirconium Alloys

    OpenAIRE

    Jerlerud Pérez, Rosa

    2006-01-01

    For many decades zirconium alloys have been commonly used in the nuclear power industry as fuel cladding material. Besides their good corrosion resistance and acceptable mechanical properties the main reason for using these alloys is the low neutron absorption. Zirconium alloys are exposed to a very severe environment during the nuclear fission process and there is a demand for better design of this material. To meet this requirement a thermodynamic database is useful to support material desi...

  11. 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...

  12. Structure of ordered alloys

    International Nuclear Information System (INIS)

    Recent progress in studying ordered alloys by lattice fringe imaging is reviewed. Firstly the optimum experimental conditions for producing images suitable for interpretation are outlined. Secondly lattice and conventional imaging are compared and the advantages of the former for obtaining atomic level detail and compositional estimates are described. Finally some important results from this program are discussed, particularly the evidence for a microdomain model of short-range order and the fine structure of various ordered lattice defects

  13. 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.

  14. 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)

  15. 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.

  16. Amorphous yttrium-iron alloys

    International Nuclear Information System (INIS)

    The magnetic properties of amorphous yttrium-iron alloys Ysub(1-x)Fesub(x) have been studied over a wide concentration range 0.32 2Fe17 alloys, lead in the amorphous state to spin-glass behaviour and asperomagnetic order. The dominant positive interactions produce short-range ferromagnetic correlations which persist up to room temperature. However magnetic saturation cannot be achieved for any of the alloys in applied fields of up to 180 kOe, indicating that strong negative interactions are also present. Exchange interactions become increasingly positive with increasing x, and the magnetic properties of iron-rich alloys approach those of a normal ferromagnet. (author)

  17. Titanium and titanium alloy forgings

    International Nuclear Information System (INIS)

    The specification covers nine grades of annealed titanium and titanium alloy forgings as follows: Grade F-1, F-2, F-3, and F-4 unalloyed titanium; Grade F-5 titanium alloy (6% aluminum, 4% vanadium); Grade F-6 titanium alloy (5% aluminum, 2.5% tin); Grade F-7 and F-11 unalloyed titanium plus palladium; Grade F-12 titanium alloy (0.3% molybdenum, 0.8% nickel). The specification includes ordering information, manufacture, chemical requirements, mechanical requirements, nondestructive tests, dimensions and permissible variations, finish, certification, packaging, and marking

  18. Behaviour of metals and alloys in molten fluoride media

    International Nuclear Information System (INIS)

    Fluoride salts are contemplated for Generation IV nuclear systems which structural materials need to resist corrosion at high temperatures. Corrosion of metals in molten fluorides has been investigated in support of the Molten Salt Reactor's development and led to an optimized alloy, Hastelloy-N, but it lacked fundamentals data for the comprehension of materials' degradation mechanisms. The main objective of this work is then to help with the understanding of the corrosion behaviour of nickel and its alloys in fluoride salts. An experimental method was built up using electrochemical techniques and enabled to investigate the thermochemical conditions of the media and the influence of different parameters (media, temperature and quantity of impurities) on the behaviour of the materials. Most tests were performed in LiF-NaF mixtures between 800 and 1000 C. Pure metals can be classified as follows: Cr ≤ Fe ≤ Ni ≤ Mo ≤ W in increasing stability order and two specific behaviours were evidenced: Cr and Fe corrode in the melt, whereas Ni, Mo and W are stable, underlining the significance level of the redox couple controlling the reactions in the mixture. Moreover, corrosion current densities increase with temperature, fluoro-acidity and the quantity of dissolved oxide in the melt. Binary Ni-Cr alloys were also tested; selective attack of Cr is first observed before both elements are oxidized. Combining thermochemical calculations and experimental results enables to propose an approach to establish an optimized composition for a stable alloy. Immersion tests were finally achieved in addition to the electrochemical tests: interpretations of both methods were compared and completed. (author)

  19. Effects of Sn contents and final annealing temperatures on the corrosion characteristics of Zr alloys

    International Nuclear Information System (INIS)

    The effects of Sn contents and final annealing treatments on the corrosion properies of Zr-1.5Nb-xSn (x= 0.0-0.2 wt.%) alloys were evaluated sysmatically. The final treatment of the alloys was carried out at the temperature range of 400 to 800 .deg. C for 2.5 hours. The final treatment at 470 .deg. C and 570 .deg. C did not affect the corrosion properties with the variation of Sn contents. But the corrosion resistance of the specimens annealed at 640 .deg. C was inferior to the that at 470. deg. C and 570 .deg. C and increased as the increase of Sn contents. This means that Zr-1.5Nb-xSn alloys, of which Nb content is higher than solubility limit, would form the β-Zr phase in the case of 640 .deg. C-final annealing. The crystallization and grain growth of Zr-1.5Nb-xSn alloy was retarded with the increase of Sn contents. Because of the lattic distortion caused by Sn addition, the Sn addition in Zr-1.5Nb-xSn alloys could affect the interferance in the movement of dislocation and crystal interface

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. Microstructure and shape memory effect of Ti-20Zr-10Nb alloy

    International Nuclear Information System (INIS)

    The microstructure, martensitic transformation behavior and shape memory effect of Ti-20Zr-10Nb shape memory alloy have been studied by X-ray diffraction (XRD), optical microscopy (OM) and transmission electron microscopy (TEM) observation, differential scanning calorimetry (DSC) and tensile stress-strain measurements. The results show that the recrystallization occurs in the cold rolled Ti-20Zr-10Nb alloy by annealing at 600 deg. C and the grain size goes up with the increasing annealing temperature up to 800 deg. C. The Ti-20Zr-10Nb alloy is primarily composed of α'' martensite and a small amount of ω phase which appears after annealing. A reverse martensite transformation temperature higher than 500 deg. C upon heating has been detected for the Ti-20Zr-10Nb alloy annealed at 600 deg. C, but no obvious exothermic behavior can be found upon cooling. The tensile strength and the failure strain of the alloy are measured to be 542 MPa and 13.1%, respectively, associated with a maximum shape recovery strain of about 2.5%.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Characterization of Fe–Cr alloy metallic interconnects coated with LSMO using the aerosol deposition process

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Lanthanum strontium manganite (LSMO) as the protective layer for metallic interconnects was successfully prepared by aerosol deposition method (AD). • The microstructure, electrical resistance and composition for LSMO-coated Fe–Cr alloys undergoing high temperature, long-hour oxidation were investigated. • The denser protective layer prepared by AD might effectively prohibit the growth of oxidized scale after long time running at 800 °C in air. - Abstract: A Fe–Cr alloy, used for metallic interconnects, was coated with a protective layer of lanthanum strontium manganite (LSMO) using the aerosol deposition method (AD). The effects of the LSMO protective layer, which was coated on the Fe–Cr interconnects using AD, on the area specific resistance (ASR) during high temperature oxidation and the Cr evaporation behaviors were systematically investigated in this paper. The microstructures, morphologies, and compositions of the oxidized scales that appeared on the LSMO-coated Fe–Cr alloy after annealing at 800 °C for 750 h in air were examined using SEM equipped with EDS. The EPMA mapping of the LSMO-coated Fe–Cr interconnects undergoing long term, high-temperature oxidation was used to explain the formation layers of the oxidized scale, which consists of (Mn,Cr)3O4 and Cr2O3 layers. Moreover, the experimental results revealed that the AD process is a potential method for preparing denser protective layers with highly desirable electrical properties for metallic interconnects

  10. Development of Nb-1% Zr-0.1%C alloy as structural components for CHTR

    International Nuclear Information System (INIS)

    The Nb-1Zr-0.1C (wt%) alloy is being considered for structural components in the proposed Compact High-Temperature-Reactors (CHTR). The present work reports on the development of 30-50 kilogram ingots of the alloy in correct composition as well as technology for forming the material in various shapes. The work deals with the deformation behavior of as-cast material at different temperatures and strain rates, recrystallization behavior at different temperature and time and evolution of microstructures at different processing conditions (as-cast, deformed and recrystallized). The as-cast Nb alloys were deformed up to 35% at different temperatures. The deformation results showed that the flow stress of the as-cast Nb alloy increases with increasing temperature from 800 degC to 1000 degC. Beyond 1000 degC, substantial decrease in the strength of the alloy was noticed. To determine the optimum recrystallization temperature and time for the alloy, several heat treatments were conducted by systematically varying temperature and time. It was found that the deformed Nb alloy could be recrystallized by annealing at 1300 degC for 3 h. The microstructures of the as-cast, deformed and recrystallized samples of Nb-1%Zr-0.1%C alloy were systematically characterized by optical, EBSD and transmission electron microscopy techniques. The Nb-1Zr-0.1C alloy showed significant differences in the microstructure after different thermo-mechanical treatments. Microstructure of Nb alloy showed two phases: the matrix (bcc) phase and the carbide phase. Electron Microscopy and energy dispersive spectroscopic analyses revealed that the carbide precipitation undergoes various phase transformations. The as-cast structure of Nb alloy had hexagonal Nb2C precipitates in the Nb matrix and after extrusion, the deformed microstructure had two types of carbide precipitates: needle and rectangular morphology precipitates. The needle shape precipitates were of (Nb,Zr)2C with orthorhombic structure and

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. Solid-state Diffusion Bonding of Candidate Fe-base and Ni-base Alloys for the Application of S-CO2 Cycle Heat Exchanger

    International Nuclear Information System (INIS)

    To achieve efficient heat transfer, compact type heat exchangers, such as printed circuit or plate fin type heat exchanger, are considered for intermediate heat exchangers (IHXs). Solid-state diffusion bonding (DB) is one of key issues for joining the thin metal sheets with flow passages that are either machined or photo-chemically etched. In this study, diffusion bonding was performed for the candidate Fe-base and Ni-base alloys. Tensile properties of the as-bonded were compared with the as-received and characteristics of the aged in high temperature S-CO2 environment were discussed. Studies on diffusion bonding of candidate alloys for the application of super-critical CO2 cycle were carried out. Strength ratios were close to 1 for Fe-base alloys (F91, SS 316H, and SS 347H), while those of Ni-base alloys (Alloy 600, Alloy 690) and Fe-Ni-Cr alloy (Incoloy 800HT) were somewhat decreased to about 0.8 due to the planar grain boundary and precipitates formed along the bond-line. After exposure in high temperature S-CO2 environment for 1000 h, mechanical properties were not changed substantially and the location of the failure was still in the gauge section away from the bond-line for most alloys. Thus, bond-line which plays a role as grain boundary is thought to have superior corrosion and carburization resistance comparable to that of parent matrix

  16. Electron Theory in Alloy Design

    CERN Document Server

    Pettifor, DG

    1992-01-01

    Presents recent developments in electron theory which have impacted upon the search for novel alloys with improved mechanical or magnetic properties. The ten chapters outline the ability of electron theory to make quantitative predictions (such as heats of formation, planar fault energies, shear moduli and magnetic anisotropy), and to provide simplifying concepts for understanding trends in alloy behaviour.

  17. 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

  18. Effect of activity differences on hydrogen migration in dissimilar titanium alloy welds

    International Nuclear Information System (INIS)

    The effect of alloy composition on hydrogen activity was measured for seven titanium alloys as a means to determine the tendency for hydrogen migration within dissimilar metal welds. The alloys were: Ti-CP (unalloyed Ti), Ti-3Al-2.5V, Ti-3Al-2.5V-3Zr, Ti-3Al-2Nb-1Ta, Ti-6Al, Ti-6Al-4V, and Ti-6Al-2Nb-1Ta-0.8Mo. Hydrogen pressure-hydrogen concentration relationships were determined for temperatures from 600 C to 800 C and hydrogen concentrations up to approximately 3.5 at. pct (750 wppm). Fusion welds were made between Ti-CP and Ti-CP and between Ti-CP and Ti-6Al-4V to observe directly the hydrogen redistribution in similar and dissimilar metal couples. Hydrogen activity was found to be significantly affected by alloying elements, particularly Al in solid solution. At a constant Al content and temperature, an increase in the volume fraction of β reduced the activity of hydrogen in α-β alloys. Activity was also found to be strongly affected by temperature. The effect of temperature differences on hydrogen activity was much greater than the effects resulting from alloy composition differences at a given temperature. Thus, hydrogen redistribution should be expected within similar metal couples subjected to extreme temperature gradients, such as those peculiar to fusion welding. Significant hydrogen redistribution in dissimilar alloy weldments also can be expected for many of the compositions in this study. Hydride formation stemming from these driving forces was observed in the dissimilar couple fusion welds. In addition, a basis for estimating hydrogen migration in titanium welds, based on hydrogen activity data, is described

  19. 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.

  20. 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.

  1. 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.)

  2. 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

  3. Heave Compensated GLAD800 Coring from the R/V Knorr: a Progress Report

    Science.gov (United States)

    Nielson, D.; Mountain, G.; Pardey, M.; Austin, J.; Alexander, C.

    2001-12-01

    Despite potential applications to studies of stratal architecture, sea-level history, land-sea interaction, and rapid climate change, scientific drilling with high core recovery in shallow marine settings has been thwarted by several challenges. Among these has been the problem of maintaining hole stability while penetrating unconsolidated lithologies from a floating, open-ocean platform. We report on progress in overcoming this barrier. The GLAD800 coring system, originally developed as a joint venture between the International Scientific Drilling Program and DOSECC to collect long, high-resolution cores in modern lakes, has been adapted for deploying from the R/V Knorr. As in lake-based operations, the drilling system can continuously sample sediments of different composition and stiffness to a total depth of 800m below the rig floor using HWT drill rods and riser pipe. Core is collected in standard ODP-size plastic liners. A modular design provides inexpensive and easily transportable operations. The latest advance is the installation of an active heave compensation (AHC) system that accommodates as much as 8 feet of vertical rig motion. This minimizes excursions in the total weight of the bit at the cutting face, a major concern in achieving the high core recovery needed for scientific purposes. We show results of testing this AHC-equipped GLAD800 rig during a 5-day operation in November. We drilled through the existing 'moon pool' of the R/V Knorr on the outer shelf south of Martha's Vineyard. This technological development and ship time is funded by the Office of Naval Research, and if successful, will be extended to core numerous drill holes 10's to 100's of meters into the New Jersey shelf during 2002.

  4. Neutron powder thermo-diffraction in mechanically alloyed Fe64Ni36 invar alloy

    International Nuclear Information System (INIS)

    Nanostructured Fe64Ni36 alloy has been obtained using high-energy ball milling for 35 h of milling time, Fe64Ni36 MA-35 h. The initial as-milled Fe64Ni36 MA-35 h powders are inhomogeneous, showing a majority phase with a face-centred cubic (fcc) crystal structure [88(2)%] and a minority phase with body-centred cubic (bcc) crystal structure [7(2)%]. The evolution of the microstructure with temperature between 300 K and 1100 K has been followed by means of in situ neutron powder thermo-diffraction experiments. The room temperature values for the mean crystalline size and the mechanical-induced microstrain of the fcc phase in the as-milled sample are ∼10 nm and ∼0.7%, respectively. Moreover, after heating the Fe64Ni36 MA-35 h powders up to 1100 K, an increase of around 65 K in the Curie temperature respect to that of the commercial coarse-grained alloy of the same composition is observed. The latter together with the observed temperature dependence of the lattice parameter suggests that the Fe64Ni36 MA-35 h sample subjected to the heating process exhibits invar behaviour. On heating up to 1100 K thermal relaxation of the microstructure occurs giving rise to grain growth above 100 nm, nearly vanishing values for the maximum strain, and the transformation of the bcc phase into the fcc one above 800 K, being the latter stable in subsequent heating-cooling processes.

  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. Alloyed pleasures: Multimetallic cocktails

    OpenAIRE

    Ranganathan, S

    2003-01-01

    The English language insists on unalloyed pleasures, thereby implying that the sensation of pleasure must be pure and not admixed with other emotions. Exactly the opposite rules in metallurgy, where pure metals have few uses and can always be improved upon by alloying. It is true that the civilizational journey of mankind began with the discovery of native metals such as gold and copper as pure metals. In fact this love at first sight of gold several millennia ago has persisted till this day ...

  8. 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

  9. 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.

  10. 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...

  11. 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.

  12. 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)

  13. 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

  14. Two body photodisintegration of the deuteron from 100 to 800 MeV

    International Nuclear Information System (INIS)

    The total and the differential cross sections for the D(γ,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)

  15. 800,000 year old mammoth DNA, modern elephant DNA or PCR artefact?

    DEFF Research Database (Denmark)

    Binladen, Jonas; Gilbert, M Thomas P; Willerslev, Eske

    2007-01-01

    Poulakakis and colleagues (Poulakakis et al. 2006: Biol. Lett. 2, 451-454), report the recovery of 'authentic' mammoth DNA from an 800,000-year-old fragment of bone excavated on the island of Crete. In light of results from other ancient DNA studies that indicate how DNA survival is unlikely in s...... polymorphisms. Finally, we demonstrate using a simple BLAST search in GenBank that the claimed 'uniquely derived character state' for mammoths is in fact also found within modern elephants. Udgivelsesdato: 2007-Feb-22...

  16. 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.

  17. 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...

  18. 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 ...

  19. 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.

  20. 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.