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Sample records for heat-resistant alloy hastelloy

  1. Filler metal development for hastelloy alloy XR

    International Nuclear Information System (INIS)

    A method of alloy designing has been proposed and validated to develop the filler metal for Hastelloy alloy XR(nuclear reactor grade of Hastelloy alloy X), which is the candidate material for high temperature structure of High-Temperature Engineering Test Reactor (HTTR). In the filler metal development for Hastelloy alloy XR, materials of two heats were melted and fabricated with special emphasis placed on manufacturing process. One is the trial products (alloy termed 'C') designed by using multiple regression analysis in the range of the chemical composition specified as Hastelloy alloy X. The other is filler metal (alloy termed 'D') with optimum boron content in the same chemical composition as Hastelloy alloy XR. The results of the tests on several key items may be summarized as follows: (1) Weldments with alloy'C' showed higher strength and ductility at elevated temperatures than those of alloy'D'. (2) Weldments with alloy'D' had more excellent strength characteristics at elevated temperatures than those of the other conventional filler metals. (3) As for weldability, the crater cracks were slightly observed in the FISCO cracking test, but those were out of the problem in the degree of cracking from the viewpoint of practical application. The results of qualification tests on weldability showed good performance for all welding conditions of the present experiments. On the other hand, the mechanism of hot cracking initiation and the controlling factors in hot cracking susceptibility with relation to boron content have been clarified for Hastelloy alloy XR base metal. (author)

  2. Studies on neutron irradiation effects of iron alloys and nickel-base heat resistant alloys

    International Nuclear Information System (INIS)

    The present paper describes the results of neutron irradiation effects on iron alloys and nickel-base heat resistant alloys. As for the iron alloys, irradiation hardening and embrittlement were investigated using internal friction measurement, electron microscopy and tensile testings. The role of alloying elements was also investigated to understand the irradiation behavior of iron alloys. The essential factors affecting irradiation hardening and embrittlement were thus clarified. On the other hand, postirradiation tensile and creep properties were measured of Hastelloy X alloy. Irradiation behavior at elevated temperatures is discussed. (author)

  3. Electron beam welding of dissimilar heat resistant alloys

    International Nuclear Information System (INIS)

    To the welding of the different heat resistant materials for high temperature gas-cooled reactors, electron beam welding was applied, and the high temperature strength of the weld metal was examined as it is necessary for evaluating the welded joints. As the results, the high temperature strength of the weld metal of Hastelloy X and 2.25 Cr-1Mo steel at 500 degC and that of Hastelloy X and SUS316 at 600 degC showed the nearly intermediate values of both parent materials in both cases. Accordingly, when the high temperature strength of electron beam welded metals is evaluated, it is considered that by evaluating at least with the value of a lower strength parent metal, sufficient safety is ensured. In this study, the electron beam welded joints of typical different heat resistant alloys were made, and the tesile strength, creep rupture strength and low cycle fatique strength of the weld metals at high temperature were determined to compare with those of parent alloys. The tested alloys, welding method and high temperature tests are reported. (Koko, I.)

  4. Diffusion welding of molybdenum to hastelloy alloy X

    International Nuclear Information System (INIS)

    Diffusion welding between pure molybdenum and heat-resisting alloy hastelloy X has been performed in vacuum at the temperature range of 7500C -- 12000C. Tensile strength of the weld joint at room temperature is discussed on the effects of methods in welding technique and a use of Ni insert-metal. The use of two steps welding technique and a Ni insert-metal is appreciable to improve the tensile strength of weld joint, but the fracture had occured always near weld bond. Metallographical investigations using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction analysis and electron probe X-ray microanalysis have been performed in order to clarify the effects of two steps welding technique and a use of Ni insert-metal on the microstructure near the bonding interface. Results obtained are summarized as follows; (1) Two steps welding technique including a short time annealing at high temperature (1 minute at 12000C) increases the real metal-contact between molybdenum and hastelloy X, and takes the improvement of the joint strength. Furthermore, this technique is useful not to enlarge the deformation by welding procedure. (2) Application of the Ni insert-metal suppresses the formation of the brittle intermetallic compound, P phase, and increases the tensile strength. However the formation of binary compound, delta-MoNi, was observed at the bonding interface. (3) Fracture of the weld joints by the tensile strength tests has occurred always through the intermetallic compounds and also along the grain boundaries of molybdenum base metal. (4) After the welding procedure, the voids and MoO2 were found out at the grain boundaries of molybdenum using SEM and TEM techniques. (auth.)

  5. Thermomechanical treatment of heat-resisting alloys

    International Nuclear Information System (INIS)

    Different types of thermomechanical treatment (TMT) are considered in the review. Three schemes which are used for heat resistant ageing alloys are singled out and described in detail: high-temperature thermomechanical treatment (HTMT), mechanico-thermal treatment (MTT) and low-temperature thermomechanical treatment (LTMT). Special attention is paid to perspective LTMT including warm deformation. It is shown that the application of the TMT to concrete alloys permits to increase the strength characteristics in a certain temperature range of the product exploitation without considerable plasticity loss. TMT with the use.of warm deformation in two-phase region looks like the most perspective treatment increasing strength properties, resistance against fatigue destruction and decreasing the sensitivity to the cut

  6. Compatibility of heat resistant alloys with boron carbide, (4)

    International Nuclear Information System (INIS)

    This paper relates to the compatibility test of control rod sheath (Hastelloy XR alloy) and neutron absorber (boronated graphite) for the VHTR, which has been researched and developed by JAERI. The irradiation was conducted by using the OGL-1 irradiation facility in the JMTR in order to study reaction behaviour between Hastelloy XR alloy and boronated graphite as well as to determine a reaction barrier performance of refractory metal foils Nb, Mo, W and Re. Irradiation conditions were as follows. Neutron dose : 4.05 x 1022 m-2 (E 18 m-2 (E > 0.16 pJ, 1 Mev). Helium coolant : Average temperature 855 0C, Pressure 2.94 MPa, Total impurity concentration 400 kBq/m3. Irradiation time : 5.0 Ms (1390 hours). Post-irradiation examinations i.e. visual inspection, dimensional inspection, weight measurement, metallography, hardness test, morphological observations by SEM and analysis of element distributions by EPMA were carried out. In the result, reaction products of Hastelloy XR alloy were observed in the ellipsoidal form locally. These results were same as those of the out-of-pile tests. Obvious irradiation effects were not detectable but a little accelarated increase in reaction depth of Hastelloy XR alloy by heat effect of specimens was observed. The refractory metal foils had a good performance of reaction barrier between Hastelloy XR alloy and boronated graphite. Furthermore, movement of Ni, Fe and Cr in the reaction area of Hastelloy XR alloy, difference in the reaction depth of B and C, irradiation effects on diffusion coefficient, lithium production and heat effect are discussed. (author)

  7. REM alloying of heat resisting nickel alloys for properties improvement

    International Nuclear Information System (INIS)

    Effect of hafnium, yttrium, and lanthanum during separate and complex alloying on the structure and properties of the wrought heat resisting KhN65KVMYuTB alloy was studied. It is established that a complex REM alloying leads both to a growth of the level of ultimate strength and impact strength at temperatures up to 800 deg C and to the increase of time to fracture. A possibility is found out pressing for high-quality large-sized billets of KhN65KVMYuTB alloy with a REM complex addition. Alloys with 0.4% Hf + 0.2% V + 0.2% La addition or separate additions of La and Hf are recommended to be used for the production of heavily loaded machine parts operating for a long time at 750-850 deg C

  8. Compatibility of heat resistant alloys with boron carbide, (2)

    International Nuclear Information System (INIS)

    In the present design of the control rod for the experimental Very High Temperature Gas-cooled Reactor, sintered pellets of boron carbide mixed with graphite are used as a neutron absorber, which are clad with the sheath material of Hastelloy XR. The sintered pellet contains 30 wt% of natural boron. Chemical reaction occurs between the neutron absorber and the sheath material when they contact mutually at elevated temperature. The term called compatibility is defined as the ability of those materials to be used together without undesirable reaction, in this report. The experimental results on the compatibility of both materials are presented and are discussed on three subjects as (1) the comparison between Hastelloy X and Hastelloy XR, (2) the long term exposure, (3) the effect of the reaction barrier. No difference was observed between Hastelloy X and Hastelloy XR within the conditions of the experiment at 8500C, 9500C and 10500C for each 100 h concerning the first subject. On the second, the penetration depth of 74 um and 156 um were observed on Hastelloy X reacted with sintered pellets (boron carbide and graphite) at 7500C for 3000 h and 8500C for 2000 h, respectively. On the third subject, Hastelloy X surfaces were coated with zirconia or alumina powder by plasma spraying process and by calorizing process in order to prevent the above mentioned reaction. These specimens were tested under two conditions: the one was a simple heat test of 10000C - 100 h and the other was five thermal cycles of 10000C - 20 h. The test results showed that no reaction occurred in the both alloys themselves and some of the coated layers were stripped or cracked. (author)

  9. Electric hydraulic treatment of welded joints of heat resistant alloys

    International Nuclear Information System (INIS)

    Electric hydraulic treatment is proposed to increase quality and service properties of welded joints of heat resistant alloys and steels. Results of experiments using samples of EhI698 nickel alloy and 12Kh18N10T steel show that electric hydraulic effect relaxes residual stresses preventing from crack formation after welding. Presented are process scheme and treatment conditions

  10. Corrosion behavior of heat resistant alloys for gas seal elements of VHTR in helium environment

    International Nuclear Information System (INIS)

    The corrosion behavior of the heat resistant alloys for the gas seal elements used for the fixed reflectors to improve the thermal flow characteristics in the core of the high tempeerature gas-cooled experimental reactor was examined in helium. As the results, the following facts were clarified. In Hastelloy X and Incoloy 800, carburization was observed below 900 deg C. Especially in the state of contact with graphite, carburization was promoted more than the case of non-contact. In Incoloy MA 956, decarbonization and carburization were suppressed below 800 deg C in helium, but in the state of contact with graphite, carburization was observed. When Al2O3 was coated on the surfaces of test pieces by chemical vacuum evaporation, oxidation, decarbonization and carburization were suppressed. The Al2O3 film coated on Hastelloy X by chemical vacuum evaporation showed sufficient reliability against thermal cycles and repeated bending. In the high temperature gas-cooled experimental reactor, the crossflow of helium through the gaps between graphite blocks lowers the thermal flow characteristics, therefore, the use of the gas seal elements made of 0.4 mm metallic sheets is considered. It is required to examine the reaction with the impurities in helium and the reaction in contact with graphite. (Kako, I.)

  11. Studies on the quality optimization of hastelloy alloy XR

    International Nuclear Information System (INIS)

    Interim results are reported on the multi-lateral joint research program on improving quality and its assurance basis of Hastelloy alloy XR with special emphasis placed on the effect of small amount of boron in the alloy. In the first phase work the exploratory examination on the optimum boron content was made. The results of the tests on several key items yield the optimum range of boron content as 40 to 70 ppm. The second phase work was organized to perform qualification tests on an industrial scale heat, which was specified its boron content (40 ppm) based on the previous phase work. The tests included weldability, tensile and creep-rupture properties, post aging toughness and corrosion and carburization resistance on different type of products. Tests are in progress, in which considerable difference in the degree of improvement was noted between plate and tube. (author)

  12. 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)

  13. Study of creep and rupture behavior for hastelloy alloy XR

    International Nuclear Information System (INIS)

    Creep tests of Hastelloy alloy XR (a modified Hastelloy alloy X developed for VHTR application) were carried out at 800, 900 and 10000C up to 310,000 hours in total testing times. The effects of environment (air and simulated VHTR helium), specimen diameters, product forms of the material (tube, plate and bar) and the neutron irradiation were also investigated. The ASME allowable stresses (Ssub(o), Ssub(m), and Ssub(t) in Code Case N-47) required to establish the design limit on the primary system were calculated using the current data. A procedure was developed to calculate equations which represented lower limits of the prediction intervals and the simultaneous tolerance intervals of strength on the basis of regression analysis. Statistical analysis of the three time-temperature parameter methods showed that the Manson-Succop method was better than that of either Larson-Miller or Orr-Sherby-Dorn in respect of curve fitting to the present creep-rupture data. Application of the Garofalo equation to the strain-time data resulted in a creep constitutive equation (tentative version) which represented the average isochronous stress-strain curves. It was recognized that there was little difference between air and helium in the creep-rupture strength up to about 10,000 hours. In helium environment there appeared slight indication that carburization occured in the early stage of exposure but no further carbon intrusion was observed in the steady state creep range. Comparison of creep behaviors among three product forms of the same heat indicated that the bar had superior creep-strength to the tube. This was attributed to the banded precipitation of carbides in the tube. As a result of significant ductility loss due to the neutron irradiation up to 8.7 x 1020n/cm2(th) at 600C, the rupture times reduced below about 20% that of the unirradiated one. (author)

  14. Etude expérimentale du soudage par laser YAG de l'alliage base nickel Hastelloy X Experimental study of YAG laser welding of nickel base alloy Hastelloy X

    Directory of Open Access Journals (Sweden)

    Graneix Jérémie

    2013-11-01

    Full Text Available Le procédé de soudage laser YAG est envisagé pour remplacer le procédé de soudage TIG manuel pour la réalisation de pièces de turboréacteur en alliage nickel-chrome-molybdène Hastelloy X. Cette étude expérimentale a permis de définir un domaine de soudabilité de cet alliage répondant aux critères spécifiques du secteur aéronautique. The YAG laser welding process is contemplated to replace the manual TIG welding process for the production of parts of turbojet in Hastelloy X. This experimental study has identified the field of weldability of this alloy to meet the specific requirements of the aerospace industry.

  15. Permeation of hydrogen in hastelloy C-276 alloy at high temperature

    International Nuclear Information System (INIS)

    Tritium is generated by the interaction of neutrons with the lithium and beryllium in the molten salt reactors (MSRs), which use FLiBe as one of solvents of fluoride fuel. Tritium as by-product in the MSRs is an important safety issue because it could easily diffuse into environment through high temperature heat exchangers. The experimental technique of gas driven permeation has been used to investigate the transport parameter of hydrogen in Hastelloy C-276 which is considered as one of the candidate for structure materials. The measurements were carried out at the temperature range of 400-800 Celsius degrees with hydrogen loading pressures ranging from 5*103 to 4*104 Pa. The H diffusive transport parameters for Hastelloy C-276 follow an Arrhenius law in this temperature range. Regarding diffusivity and Sieverts' constant, Hastelloy C-276 has lower values compared with Ni201 alloy. The possible reason may be the trapping effects, which were formed by the alloying elements of Mo and Cr in the matrix. At the same time, the thin oxidation layer formed by the high Cr content could lead to a slower dissociation process of H2 at the surface. (authors)

  16. Development of thermal insulation layers for heat-resisting alloys

    International Nuclear Information System (INIS)

    The dissertation examines means and possibilities of treating the surface of commercial alloys used for turbines in order to enhance their corrosion resistance of high temperatures (hot-gas corrosion), and to achieve a thermal insulation against flowing hot gas. The thermal insulation layer is to consist of high-melting oxides. The adhesiveness of oxides on metals is known to be insufficient, due to thermomechanical stresses and to low adhesive forces between metals and ceramics. Hence suitable bonding agents have to be found that comply with the required hot-gas corrosion resistance. The studies showed the following layer composition to be suitable: (1) INCONEL 617, (2) with helical wires tip brazed with Ni4Cr2Ti0.5Si2.5 (wire diameter 0.3 mm, spiral diameter 3 mm), (3) soda-lime glass with addition of ZrO2/Y2O3, and (4) topmost thermal insulation layer made of 10 vol-% aluminium silicate fibre, 70 vol.-% ZrO2/7Y2O3, 5 vol.-% GeO2 and 15 vol.-% of a gel (consisting of 61 mol-% Si (OH)4/20 mol-% Y(OH)3 and 19 mol-% Zr (OH)4). This layer composition allows to deposit thermal insulation layers of more than two millimetres in thickness onto nickel-base alloys. (orig.)

  17. Processing parameters effect on dendritic segregation in heat resistant nickel alloy

    International Nuclear Information System (INIS)

    Study on impact of the scheme for melting the ingots-electrodes diameter 85 mm of heat-resistant nickel alloy is carried out through the methods of track, activation autoradiography, metallographic and microroentgen-spectra analysis with application of vacuum arc, electroslag, electrobeam, vacuum arc two-electrode remelting, as well as ingots thermal and heat isostatic treatment for dendrite liquation of boron and carbon in the heat resistant nickel alloy Ni-5Al-2Ti-9Cr-16Co-6W-4Mo-3Nb-Hf-C-B. Regularities of the melting scheme impact on dendrite structure dispersity and the level of dendrite liquation development are established. The mechanism of the melting scheme impact on liquation is proposed

  18. 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 ?g/cm2 and ceased when diffusing carbon reached the center of the specimen. (Auth.)

  19. Creep curve modeling of hastelloy-X alloy by using the theta projection method

    International Nuclear Information System (INIS)

    To model the creep curves of the Hastelloy-X alloy which is being considered as a candidate material for the VHTR (Very High Temperature gas-cooled Reactor) components, full creep curves were obtained by constant-load creep tests for different stress levels at 950 C degrees. Using the experimental creep data, the creep curves were modeled by applying the Theta projection method. A number of computing processes of a nonlinear least square fitting (NLSF) analysis was carried out to establish the suitably of the four Theta parameters. The results showed that the ?1 and ?2 parameters could not be optimized well with a large error during the fitting of the full creep curves. On the other hand, the ?3 and ?4 parameters were optimized well without an error. For this result, to find a suitable cutoff strain criterion, the NLSF analysis was performed with various cutoff strains for all the creep curves. An optimum cutoff strain range for defining the four Theta parameters accurately was found to be a 3% cutoff strain. At the 3% cutoff strain, the predicted curves coincided well with the experimental ones. The variation of the four Theta parameters as the function of a stress showed a good linearity, and the creep curves were modeled well for the low stress levels. Predicted minimum creep rate showed a good agreement with the experimental data. Also, for a design usage of the Hastelloy-X alloy, the plot of the log stress versus log the time to a 1% strain was predicted, and the creep rate curves with time and a cutoff strain at 950 C degrees were constructed numerically for a wide rang of stresses by using the Theta projection method. (authors)

  20. Surface microprofile production in electrochemical machining of heat-resistant nickel-chromium alloys

    International Nuclear Information System (INIS)

    Surface microprofiling of some heat-resistant nickel-chromium alloys by electrochemical processing in chloride and ''passivating'' electrolytes is studied. It is shown that the existence of strengthening ?'-phase in the alloy, differing in its anode behaviour from nickel-chromium matrix, brings about different roughnesses, formed during processing in different electrolytes. Processing in chlorides is accompanied by etching of grain boundaries as far as in ''passivating'' electrolytes bumps are formed on the surface which is connected with difference in velocities of anode dissolving of different phases. In increasing the current density and using mixed chloride-nitrate electrolytes one can reduce the height of microroughnesses

  1. Electric effect on formation of gas-circulation coatings on heat resistant alloy

    International Nuclear Information System (INIS)

    The formation kinetics for aluminide coating on heat resisting alloy ZhS6U is under study. Polished specimens to be coated were mounted in a reaction chamber with a NiCrAlY powder saturating mixture placed at the bottom. Electric potential was applied between heated ZhS6U alloy specimens and the bottom of the chamber. It is shown that the application of pulsed electric potentials accelerates the growth of diffusion coatings on the alloy. Electric field effect starts at some definite threshold value of direct voltage and manifests itself near the temperature of gamma-phase dissolution in the alloy. The application of pulsed electric potentials makes it possible to form multicomponent coatings of variable composition

  2. Development testing of the two-watt RTG heat source and Hastelloy-S/T-111 alloy compatibility studies

    International Nuclear Information System (INIS)

    The two-watt radioisotope thermoelectric generator heat source capsules were tested to determine their survivability under extreme environmental conditions: high external pressure, high impact, and high internal pressure. Test results showed that the capsules could withstand external pressures of 1,000 bars and impacts at velocities near 150 meters per second. However, the results of the internal pressure tests (stress-rupture) were not so favorable, possibly because of copper contamination, leading to a recommendation for additional testing. A material compatibility study examined the use of Hastelloy-S as a material to clad the tantalum strength member of the two-watt radioisotopic heat source. Test capsules were subjected to high temperatures for various lengths of time, then cross sectioned and examined with a scanning electron microscope. Results of the study indicate that Hastelloy-S would be compatible with the underlying alloy, not only at the normal operating temperatures of the heat source, but also when exposed to the much higher temperatures of a credible accident scenario

  3. Heat-resistant alloys: State-of-the-art and trends of development

    International Nuclear Information System (INIS)

    Even today, several decades after inception, nickel-based heat-resistant alloys are still considered to be a class of materials meeting the broadest range of stringent requirements comprising mechanical, process, corrosion-resistant and physico-chemical properties. In the opinion of this author, the opportunities for new alloys to be used are as follows: High-temperature regions in phase diagrams show the compositions which can serve as a basis for new generations of alloys. In addition ceramics based on carbides, nitrides and so on will be used. High-temperature regions are, first of all, connected with utilization of such high-melting intermetallic compounds as NiAl, Co3Ti, TiAl as well as CoAl, Co3Al, Ni3Al and others. (orig./MM)

  4. The effects of controlled impurity helium on the mechanical behavior of Hastelloy Alloy X

    International Nuclear Information System (INIS)

    The influence of a simulated advanced reactor helium environment, containing 50 Pa H2/5 Pa CH4/ 5 Pa CO/ about 0.1 Pa H2O, on the mechanical properties of two heats of Hastelloy alloy X is discussed. Simultaneous exposures in air and controlled impurity helium at temperatures in the range of 650 to 10000C for times of 3000 h or more were performed. A combination of tensile testing, Charpy V-notch impact toughness testing, and creep testing was used to study the effects of reactor helium/metal interactions on the mechanical behavior of this alloy. Carburization was identified as the primary corrosion phenomenon. Increasing exposure time and temperature were observed to increase the depth of carburization. The increase in carbon concentration in the carburized zone suppressed the additional formation of M C, which is observed in air-aged specimens, and resulted in the precipitation of M23C6 a chromium-rich carbide variant. The precipitation of M23C6 in the carburized zone occurred primarily along grain and twin boundaries; matrix precipitation, however, was also observed, the degree of which depended on exposure temperature. Strength and impact toughness properties were found to be controlled primarily by thermal aging reactions, with only a small effect related to the carburization. Although tensile and creep ductilities were decreased as a result of carburization, substantial ductility remained. Variation was observed between the two heats, the finer grained heat appearing to be weaker in the high-temperature creep tests and also possibly more susceptible to a loss of creep strength as a result of carburization

  5. Comparison of creep behavior under varying load/temperature conditions between Hastelloy XR alloys with different boron content levels

    International Nuclear Information System (INIS)

    In the design of the high-temperature components, it is often required to predict the creep rupture life under the conditions in which the stress and/or temperature may vary by using the data obtained with the constant load and temperature creep rupture tests. Some conventional creep damage rules have been proposed to meet the above-mentioned requirement. Currently only limited data are available on the behavior of Hastelloy XR, which is a developed alloy as the structural material for high-temperature components of the High-Temperature Engineering Test Reactor (HTTR), under varying stress and/or temperature creep conditions. Hence a series of constant load and temperature creep rupture tests as well as varying load and temperature creep rupture tests was carried out on two kinds of Hastelloy XR alloys whose boron content levels are different, i.e., below 10 and 60 mass ppm. The life fraction rule completely fails in the prediction of the creep rupture life of Hastelloy XR with 60 mass ppm boron under varying load and temperature conditions though the rule shows good applicability for Hastelloy XR with below 10 mass ppm boron. The change of boron content level of the material during the tests is the most probable source of impairing the applicability of the life fraction rule to Hastelloy XR whose boron content level is 60 mass ppm. The modified life fraction rule has been proposed based on the dependence of the creep rupture strength on the boron content level of the alloy. The modified rule successfully predicts the creep rupture life under the two stage creep test conditions from 1000 to 900degC. The trend observed in the two stage creep tests from 900 to 1000degC can be qualitatively explained by the mechanism that the oxide film which is formed during the prior exposure to 900degC plays the role of the protective barrier against the boron dissipation into the environment. (J.P.N.)

  6. Crevice Corrosion of Hastelloy C-276 and Inconel-625 Alloys in Chloride Environments, Determination of The Critical Crevice Solution

    International Nuclear Information System (INIS)

    The crevice corrosion of hastelloy C-276 and Inconel-625 alloys is investigated. The effect of temperature on both passive current and the critical pH (at which the passive film breaks down) is studied in detail. potentiodynamic studies have been used to determine the critical crevice solution (CCS) in terms of pH and chloride iron concentration, and passive current. The criteria of both Crolet and Old field and Sutton are used for the determination of the critical pH for crevice corrosion. The results show that the critical pH for crevice corrosion of Inconel-625 alloy as defined by Old field and Sutton seems to be a function of both temperature and chloride ion concentration, whereas the same relationship does not appear to hold between these variables and the critical pH when the Crolet criterion is applied. The critical pH of crevice solution for Inconel-625 may vary between 1.7 and 0.0 depending on environmental condition and criteria applied. However, for the case of hastelloy C-276 alloy the critical pH for crevice corrosion could not be detected when applying both criteria. The results indicate that hastelloy C-276 alloy is more resistant to crevice corrosion than Inconel-625 under the same experimental conditions. The experimental results passive current (Ipass) and de passivation pH (dpH) of this investigation could be utilized as inputs to a mathematical model employed for the prediction of incubation period required to reach the critical crevice solution composition, which leads to permanent breakdown of passive film. 10 figs., 5 tabs

  7. Etude expérimentale du soudage par laser YAG de l'alliage base nickel Hastelloy X Experimental study of YAG laser welding of nickel base alloy Hastelloy X

    OpenAIRE

    Graneix Jérémie; Beguin Jean-Denis; Pardeilhan François; Masri Talal; Alexis Joël

    2013-01-01

    Le procédé de soudage laser YAG est envisagé pour remplacer le procédé de soudage TIG manuel pour la réalisation de pièces de turboréacteur en alliage nickel-chrome-molybdène Hastelloy X. Cette étude expérimentale a permis de définir un domaine de soudabilité de cet alliage répondant aux critères spécifiques du secteur aéronautique. The YAG laser welding process is contemplated to replace the manual TIG welding process for the production of parts of turbojet in Hastelloy X. This experimental...

  8. Installation for mechanical tests of heat-resisting alloys under super-plasticity conditions

    International Nuclear Information System (INIS)

    An mechanical test installation designed on the base of the P-5 serial machine to investigate heat-resisting alloys under superplasticity conditions is described. The range of the deformation velocity is from 0.1 to 1000 mm/min with accuracy not worse than 1%. Suggested is a specimen heating system with three-zone resistance furnace, three-step heat and automatic temperature control; the system provides at +-3 deg C temperature variations a 3 deg C gradient over 280-300 mm furnace length in the temperature range from 9O0 to - 1300 deg C when measuring with 0.05 % accuracy. A high-sensitive electrical strain dynamometer permits to register tensile forces within the limits from 0.1 to 500 kg with 0.5% accuracy

  9. Effect of method for plastic working procedure on deformability of heat resisting alloys

    International Nuclear Information System (INIS)

    Presented are the results of investigation of deformability of the heat resisting KhN56BMTYUR, KhN67BMTYU alloys at the wire drawing and rolling. The deformability has been evaluated by the results of macro- and micro-analyses, by the change of metal density and mechanical properties in the process of deformation. It is found that by the rolling it is possible to obtain 3-6 mm diameter wire with high surface quality avoiding intermediate heat treatments, cleaning and grinding the wire surface. The production of the wire of the same diameter by drawing is connected with intermediate heat treatments and with the presence of surface and internal defects in the form of longitudinal and transverse cracks, tears, laminations

  10. Effects of product form and boron addition on the creep damage in the modified Hastelloy X alloys in a simulated HTGR helium gas environment

    International Nuclear Information System (INIS)

    The present paper investigates early-stage-creep damage of Hastelloy XR and XR-II alloys, modified versions of Hastelloy X alloy, which have been developed in Japan as most promising candidate structural alloys for Japanese high-temperature gas-cooled reactors (HTGRs). Creep tests were made on Hastelloy XR forging, tube and XR-II tube at 1,123 to 1,273 K in a simulated HTGR helium gas environment. The tests were interrupted at different strain levels of up to 5 % in order to evaluate creep damage via intergranular voids. The void sizes along grain boundaries and the A-parameter, the ratio of the number of damaged grain boundaries, on which one or more voids are found, to that of the total grain boundaries observed are used in order to evaluate creep damage. Statistical analysis of the A-parameter as well as the void sizes reveals that the values of the parameter show wide variations and follow the Weibull distribution, reflecting spatial randomness of the voids. The void sizes along grain boundaries, on the other hand, follow the log-normal distribution. The maximum void size dmax and the mean value of the A-parameter Am are calculated and plotted against interruption creep strain ?int. The resultant dmax vs. ?int and Am vs. ?int diagrams show that Hastelloy XR forging had suffered more damage than Hastelloy XR tube; nevertheless, the forging has longer interruption life, or the time to reach a given interruption creep strain. The result indicates that grains may have been deformed more easily in Hastelloy XR in the form of tube than in the form of forging. The diagrams also imply that the addition of boron has suppressed the nucleation as well as the growth of voids and thus has brought about longer interruption life of Hastelloy XR-II. (author)

  11. Creep-rupture properties and corrosion behavior of 2 1/4 Cr-1 Mo steel and Hastelloy X alloys in simulated HTGR environment-interim report

    International Nuclear Information System (INIS)

    Hastelloy X and 21/4 Cr-1 Mo steel are being considered as structural alloys for components of a High-Temperature Gas-Cooled Reactor (HTGR) system. Among other mechanical properties, the creep behavior of these materials in HTGR primary coolant helium must be established to form part of the design criteria. This report describes the simulated HTGR-helium environmental creep facilities, summarizes preliminary creep properties of 21/4 Cr-1 Mo steel and Hastelloy X generated in HTGR helium and compares these with data obtained by testing in air. Some corrosion characteristics of the two materials are also discussed

  12. Creep-Rupture Properties and Corrosion Behaviour of 21/4 Cr-1 Mo Steel and Hastelloy X-Alloys in Simulated HTGR Environment

    DEFF Research Database (Denmark)

    Lystrup, Aage; Rittenhouse, P. L.; DiStefano, J. R.

    1977-01-01

    Hastelloy X and 2/sup 1///sub 4/ Cr-1 Mo steel are being considered as structural alloys for components of a High-Temperature Gas-Cooled Reactor (HTGR) system. Among other mechanical properties, the creep behavior of these materials in HTGR primary coolant helium must be established to form part of the design criteria. This report describes the simulated HTGR-helium environmental creep facilities, summarizes preliminary creep properties of 2/sup 1///sub 4/ Cr-1 Mo steel and Hastelloy X generated...

  13. Aging of a cast 35Cr–45Ni heat resistant alloy

    International Nuclear Information System (INIS)

    Highlights: ? The as-cast microstructure is made of an austenitic matrix and primary carbides. ? The carbides are of two different types: Cr- and Nb-rich. ? The microstructure changes during aging. ? These microstructural changes result in the degradation of mechanical properties. - Abstract: The microstructural evolution during aging and its effect on the mechanical properties of a centrifugally cast 35Cr–45Ni heat resistant alloy was studied by means of optical and electron microscopy, and by mechanical testing in samples aged in air at 750 °C for a period of time of up to 1000 h. The as-cast microstructure consisted of an austenitic matrix and a network of two types of primary carbides that were identified as NbC and M7C3 by their light and dark tones when viewed in backscattered electron mode in a scanning electron microscope. Aging promoted the occurrence of different phenomena such as the transformation of primary M7C3 to M23C6 carbides, precipitation of secondary M23C6 carbides and the transformation of NbC to Nb3Ni2Si. It was found that aging promoted an increase in Vickers microhardness of more than 50%, the increment in tensile strength of around 20% and the reduction in ductility of close to 70%.

  14. Electrochemical investigation of the effect of different laser surface treatments on Hastelloy G alloy

    International Nuclear Information System (INIS)

    In the present study, the corrosion resistance behavior of untreated and laser treated Hastelloy was examined. The electrochemical tests including potentiodynamic polarization, Tafel analysis, and linear polarization resistance were carried out in deaerated 0.5% NaCl aqueous solution at room temperature. Surface roughness was measured to correlate it with corrosion resistance properties of the materials. Surface morphology of the samples after corrosion tests was examined using scanning electron microscopy and energy dispersive X-ray spectroscopy. Results showed that laser treated surface exhibited better corrosion resistance properties as compared to untreated surface. (orig.)

  15. Hardening mechanisms in a dynamic strain aging alloy, Hastelloy X, during isothermal and thermomechanical cyclic deformation

    Science.gov (United States)

    Miner, R. V.; Castelli, M. G.

    1992-01-01

    The relative contributions of the hardening mechanisms in Hastelloy X during cyclic deformation were investigated by conducting isothermal cyclic deformation tests within a total strain range of +/-0.3 pct and at several temperatures and strain rates, and thermomechanical tests within several different temperature limits. The results of the TEM examinations and special constant structure tests showed that the precipitation on dislocations of Cr23C6 contributed to hardening, but only after sufficient time above 500 C. Solute drag alone produced very considerable cyclic hardening. Heat dislocation densities, peaking around 10 exp 11 per sq cm, were found to develop at temperatures producing the greatest cyclic hardening.

  16. Electrochemical investigation of the effect of different laser surface treatments on Hastelloy G alloy

    Energy Technology Data Exchange (ETDEWEB)

    Toor, Ihsan H.; Yilbas, Bekir S.; Hussein, Mohammed A.; Zafar, Mohammed N. [King Fahd Univ. of Petroleum and Minerals (KFUPM), Dhahran (Saudi Arabia). Dept. of Mechanical Engineering; Karatas, Cihan [Hacettepe Univ., Ankara (Turkey). Engineering Faculty

    2013-10-15

    In the present study, the corrosion resistance behavior of untreated and laser treated Hastelloy was examined. The electrochemical tests including potentiodynamic polarization, Tafel analysis, and linear polarization resistance were carried out in deaerated 0.5% NaCl aqueous solution at room temperature. Surface roughness was measured to correlate it with corrosion resistance properties of the materials. Surface morphology of the samples after corrosion tests was examined using scanning electron microscopy and energy dispersive X-ray spectroscopy. Results showed that laser treated surface exhibited better corrosion resistance properties as compared to untreated surface. (orig.)

  17. Effects of composite scale on high temperature oxidation resistance of Fe-Cr-Ni heat resistant alloy

    OpenAIRE

    Wang Haitao; Wang Yuqing; Yu Huashun

    2009-01-01

    Fe-Cr-Ni heat resistant alloys with aluminum and silicon addition, alone and in combination, were melted using an intermediate frequency induction furnace with a non-oxidation method. By the oxidation weight gain method, the oxidation resistances of the test alloys were determined at 1,200 ìC for 500 hours. According to the oxidation weight gains, the oxidation kinetic curves were plotted and the functions were regressed by the least squares method. The results show that the oxidation kinetic...

  18. Effect of conditions of heat treatment of the heat resistant KhN73MBTYu(EhI698) alloy

    International Nuclear Information System (INIS)

    Studied was the influence of heat treatment of the EhI698 heat resistant alloy before and after welding on fracture in welded joints. The mechanical and relaxation properties of the alloy and welded joints were evaluated, and the microstructu of heat affected zone and weld metal were studied. The investigations show that the postweld quenching from 1100 deg C increases weld cracking. Proposed is the heat treatment which provides the decrease of the rate and portion of intergranular deformation under relaxation conditions. It comprises the annealing at 1100 deg C, step cooling before welding, and postweld stress-relief tempering, followed by hardening the welded joint according to the procedure elaborated

  19. Experimental evaluation of the characteristics of super-heat-resisting Nb-based and Mo-based alloys

    International Nuclear Information System (INIS)

    Both the Nb-based and Mo-based alloys have been designed and developed in order to establish the frontier technique for super-heat-resisting materials used in the liquid alkali metal environment at high temperatures. In this study, mechanical properties of the designed Nb-1Hf alloy were experimentally evaluated. In addition, the brittleness of Nb-based alloys observed at 1073K were discussed. Moreover, characteristics of both the designed Nb-based and the Mo-based alloys were summarized in a consistent way. The tensile strength of the designed Nb-1Hf alloy was slightly lower at room temperature than that of the commercial Nb-1Zr alloy. But, the designed alloy was superior in high temperature creep properties to any other solid solution hardened Nb-based alloys. In addition, the modulated structure was observed in the brittle specimen crept at 1073K, but not in the ductile specimen crept at 1273K. Therefore, it caused probably the brittleness of the Nb-1Zr alloy at 1073K. It was concluded that all the designed Nb-1Hf, Mo-15Re-0.1Zr and Mo-15Re-0.1Zr-0.1Ti alloys had an excellent total balance in the tensile and creep properties at high temperatures, corrosion resistance to liquid Li and cold-workability, compared to other experimental and commercial alloys. (J.P.N.)

  20. Aging of a cast 35Cr-45Ni heat resistant alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sustaita-Torres, Ireri A., E-mail: ireri.sustaita@gmail.com [Unidad Academica de Ingenieria, Universidad Autonoma de Zacatecas, 98000 Zacatecas (Mexico); Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, 66450 San Nicolas de los Garza (Mexico); Haro-Rodriguez, Sergio, E-mail: haros907@hotmail.com [Unidad Academica de Ingenieria, Universidad Autonoma de Zacatecas, 98000 Zacatecas (Mexico); Guerrero-Mata, Martha P., E-mail: martha.guerreromt@uanl.edu.mx [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, 66450 San Nicolas de los Garza (Mexico); Garza, Maribel de la, E-mail: maribeldelagarza@yahoo.com.mx [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, 66450 San Nicolas de los Garza (Mexico); Valdes, Eduardo, E-mail: eduardo.valdes.57@gmail.com [Instituto Tecnologico de Saltillo, 25280 Saltillo (Mexico); Deschaux-Beaume, Frederic, E-mail: deschaux@iut-nimes.fr [Mechanical and Civil Engineering Laboratories, Universite de Montpellier 2, IUT Nimes, 30907 Nimes (France); and others

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer The as-cast microstructure is made of an austenitic matrix and primary carbides. Black-Right-Pointing-Pointer The carbides are of two different types: Cr- and Nb-rich. Black-Right-Pointing-Pointer The microstructure changes during aging. Black-Right-Pointing-Pointer These microstructural changes result in the degradation of mechanical properties. - Abstract: The microstructural evolution during aging and its effect on the mechanical properties of a centrifugally cast 35Cr-45Ni heat resistant alloy was studied by means of optical and electron microscopy, and by mechanical testing in samples aged in air at 750 Degree-Sign C for a period of time of up to 1000 h. The as-cast microstructure consisted of an austenitic matrix and a network of two types of primary carbides that were identified as NbC and M{sub 7}C{sub 3} by their light and dark tones when viewed in backscattered electron mode in a scanning electron microscope. Aging promoted the occurrence of different phenomena such as the transformation of primary M{sub 7}C{sub 3} to M{sub 23}C{sub 6} carbides, precipitation of secondary M{sub 23}C{sub 6} carbides and the transformation of NbC to Nb{sub 3}Ni{sub 2}Si. It was found that aging promoted an increase in Vickers microhardness of more than 50%, the increment in tensile strength of around 20% and the reduction in ductility of close to 70%.

  1. Additional materials for welding of the EP99 heat resisting alloy with the EI868 alloy and 12Kh18N9T steel

    International Nuclear Information System (INIS)

    Presented are the results of the studies aimed at selecting an additive material for argon-arc welding process involving heat-resistant nickel EP99 alloy to be welded to the EI868 alloy and 12Kh18N9T steel. As the additive material use was made of wire made of nickel-chromium alloys and covered electrodes made of the EP367 alloy with additions of tungsten. It has been established that in order to improve the resistance of metal to hot-crack formation during argon arc welding of the EP99 alloy with the EI868 alloy, it is advisable to use an additive material of the EP533 alloy, and while welding the same alloy with the 12Kh18N9T steel, filler wire of the EP367 alloy is recommended

  2. State of surface layer and heat resistance of nickel alloy with NiCrAlY coating

    International Nuclear Information System (INIS)

    Physico-chemical state of NiCrAlY coating applied on nickel alloy was studied by methods of X-ray spectral microanalysis (RSMA), X-ray diffraction analysis (RDA), metallography and by measurements of roughnesses; heat resistance (at 1070 deg C during 100 h in the air) was also estimated depending on the coating surface roughness. The results of investigations have shown that the decrease of coating roughness from Ra=2.5-2.7 to 1.6-1.9 ?m provides the decrease of oxide film thickness on the coating surface 1.7 times, that gives evidence about the increase of heat resistance. Coating oxidation and diffusion processes between the coating and the alloy proofed lead to change in the physico-chemical state of the system considered, Co, W, Ti, V penetrate from the proofed alloy to the coating upto its external surface. Large particles of carbides of the (Cr1-xWx)23C6 type are formed on the coating-protective layer boundary; growth of Cr and W contents and decrease of Ni, Co, Al concentrations are observed

  3. Development of heat resistant Pb-free joints by TLPS process of Ag and Sn-Bi-Ag alloy powders

    Directory of Open Access Journals (Sweden)

    Ohnuma I.

    2012-01-01

    Full Text Available TLPS (Transient Liquid Phase Sintering process is a candidate method of heat-resistant bonding, which makes use of the reaction between low-melting temperature powder of Sn-Bi base alloys and reactive powder of Ag. During heat treatment above the melting temperature of a Sn-Bi base alloy, the molten Sn-Bi reacts rapidly with solid Ag particles, which results in the formation of heat-resistant intermetallic compound (IMC. In this study, the TLPS properties between Sn-17Bi-1Ag (at.% powder with its liquidus temperature of 200°C and pure Ag powder were investigated. During differential scanning calorimetry (DSC measurement, an exothermic reaction and an endothermic reaction occurred, which correspond to the formation of the e-Ag3Sn IMC phase and the melting of the Sn-17Bi-1Ag alloy, respectively. After the overall measurement, the obtained reactant consists of the Ag3Sn-IMC and Bi-rich phases, both of which start melting above 250°C, with a small amount of the residual Sn-Bi eutectic phase. These results suggest that the TLPS process can be applied for Pb-free heatresistant bonding.

  4. Methods for determining the work function of heat-resisting alloys undergoing the ionizing radiation

    International Nuclear Information System (INIS)

    Considered are methods for measuring thermoelectron characteristics of heat-resisting metals, the curve of current delay to collector being used. The design of an assembly is described which makes it possible to determine emission constants directly in the reactor active zone at different levels of its power. Presented are results of measurement of Mo work function without irradiation and under reactor irradiation

  5. Improvement of creep strength of TIG welded hastelloy X alloy joint

    International Nuclear Information System (INIS)

    The creep strength of the TIG welded joints of Hastelloy X is sometimes weaker than that of the parent material. Especially in the internal pressure creep test using cylindrical test pieces, this phenomenon appears conspicuously. This is because in the case of the cylinders having circumferential joints, the rupture time becomes short due to the enhanced creep phenomenon, in which the welded metal is pulled by the parent material having large creep rate, and its creep rate increases. In order to improve this defect, it was attempted to improve the creep strength of the welded metal by adding B, Zr and rare earth elements to the welding rods. As the result, by adding several tens ppm of B, the weldability was not harmed, and the remarkable effect of improvement was observed. Also it was found that rare earth elements were considerably effective. In the cylindrical test pieces having joints, for which these improved welding rods were used, the joints which broke in the parent material were able to be obtained. As for the case of the cylindrical test pieces having circumferential and longitudinal joints, the comparison of creep strength was carried out, but nearly the same strength was shown, and it was proposed to regard the circumferential joints as important similarly to the longitudinal joints. (Kako, I.)

  6. Heat-resistant materials

    CERN Document Server

    1997-01-01

    This handbook covers the complete spectrum of technology dealing with heat-resistant materials, including high-temperature characteristics, effects of processing and microstructure on high-temperature properties, materials selection guidelines for industrial applications, and life-assessment methods. Also included is information on comparative properties that allows the ranking of alloy performance, effects of processing and microstructure on high-temperature properties, high-temperature oxidation and corrosion-resistant coatings for superalloys, and design guidelines for applications involving creep and/or oxidation. Contents: General introduction (high-temperature materials characteristics, and mechanical and corrosion properties, and industrial applications); Properties of Ferrous Heat-Resistant Alloys (carbon, alloy, and stainless steels; alloy cast irons; and high alloy cast steels); Properties of superalloys (metallurgy and processing, mechanical and corrosion properties, degradation, and protective coa...

  7. New materials in the aerospace industries. [emphasizing heat resistant and light alloys

    Science.gov (United States)

    Gangler, J. J.

    1973-01-01

    Trends in the development of new aerospace metals and alloys are reviewed, and applications of these advanced materials in nonaerospace fields are indicated. Emphasis is placed on the light metals and the high-temperature alloys. Attention is given to the properties and uses of the high-strength aluminum alloy 7050, alpha and beta titanium alloys, dispersion strengthened superalloys, metal-metal composites, eutectic superalloys, and coated columbium alloys.

  8. Design of super heat-resisting Nb-based alloys for nuclear applications

    International Nuclear Information System (INIS)

    Nb-based alloys are ones of the promising materials for structural applications in advanced nuclear power systems. A systematic estimation for high-temperature tensile strength, high-temperature creep strength, corrosion resistance to liquid sodium and alloy density was performed in order to get useful information for the design of the Nb-based alloys, as was similarily done for Mo-based alloys. The high-temperature micro-hardness and the high-temperature tensile strength were found to be predictable using the same calculation method employed in the Mo-based alloys. The differences in the atomic radius and in the Young's modulus between the Nb atom and alloying elements were taken into account in the prediction. The melting temperature was calculated readily by taking the compositional average of melting temperatures for constituent metals, and used as an indication for the creep strength of alloys. The corrosion resistance to liquid Na was also found to be significantly lower in the Nb-based alloys than in the Mo-based alloys. In addition, the corrosion resistance of Nb-based alloys were largely varied with alloying elements. From a series of corrosion tests with various Nb-M binary alloys, alloying elements which are effective in improving the corrosion resistance were selected. Furthermore, alloy densities were estimated by taking the compositional average of the densities for constituent metals in alloy. Based on these results, a Nb-W-V-Zr system was selected as the most promising alloy for nuclear power plants. The specific properties were estimated with varying alloy compositions, even though extensive investigation is further needed to draw a conclusion on the corrosion resistance of these alloys. Finally, it was concluded that the present predicting method could provide an useful indication for the efficient design of Nb-based alloys. (author)

  9. Weldability and weld performance of a special grade Hastelloy XR modified for VHTR

    International Nuclear Information System (INIS)

    The bead welding test by EB welding and the trans-varestraint test by TIG welding were carried out, and the characteristics of the defects arising in welded parts were clarified, also the range of the correct welding parameters was determined. It was shown that the results obtained were almost similar to those of Hastelloy X. The corrosion test on the welded metal in helium atmosphere was performed, and the weight change, internal oxidation, altered layer and so on were investigated. As the results, it was clarified that the welded metal by EB and TIG weldings showed the similar properties to the parent metal, and was superior to Hastelloy X. As for the creep strength, the creep strength as the joints was evaluated on the basis of respective properties of the parent metal and the welded metal, and it was clarified that the EB joints were superior to the TIG joints. Hastelloy X is the candidate heat-resistant alloy for multi-purpose, high temperature gas-cooled reactors, and it is relatively stable against the effect of impurities in high temperature helium. In order to improve its corrosion resistance further, Japan Atomic Energy Research Institute has developed Hastelloy XR by increasing Mn content to improve surface film protection, reducing Al and Ti to prevent local oxidation, and reduced Co in view of induced radioactivity. (Kako, I.)

  10. Obtaining of plasma sprayed heat resistant coatings for niobium and its alloys

    International Nuclear Information System (INIS)

    The paper is concerned with a possibility to obtain a hot-resistant molybdenum disilicide base coating by the plasma method. It is shown that preliminary boriding of sprayed molybdenum disilicide powders permits oxygen penetration to the substrate to be removed due to formation of fluid oxide SiO2-B2O3 film in oxidative media. It is determined that plasma-sprayed coatings produced from such powders are characterized by low temperature of vitrification (700-1000 deg C), porosity absence, strong cohesion of particles, high heat-resistance

  11. Selection of canister materials: electrochemical corrosion tests of HASTELLOY C4 and other Ni-Cr(-Mo) alloys in chloride containing solutions

    International Nuclear Information System (INIS)

    Several Ni-Cr(-Mo) alloys (HASTELLOY C4, INCONEL 625, SANICRO 28, INCOLOY 825, INCONEL 690) were tested by electrochemical methods to characterize their corrosion behaviour in chloride containing solutions at various temperatures and pH-values in respect to their application as canister materials for final radioactive waste storage. Especially, HASTELLOY C4 which proved to have the highest corrosion resistance of all tested alloys was tested by the following electrochemical methods: (1) Poteniodynamic measurements to determine the characteristic potentials, passive current densities and critical pitting potentials. (2) Potentiostatic measurements in order to evaluate the duration of the incubation period at various potentials. (3) Galvanostatic measurements in order to characterize critical pitting potentials. As electrolyte 1 m H2SO4 was used, as parameters temperature, chloride content and pH-value were varied. Variation of temperature gives the following results: an increase in temperature leads to an increase of the critical passivation current density, the passive potential bandwidth decreases slightly and the passive current density increases with rising temperature. The addition of different chloride contents to the H2SO4 solution shows the following effects: the critical passivation current density and the passive current density increase with increasing chloride concentration and both, the critical pitting potentials and the pitting nucleation potentials, shift towards negative values. As third parameter the pH-value was varied. As expected, an increase of the pH-value extends the passive region to more negative values, the passive current density decreases. The variation of the pH-value does not affect the critical pitting potential. All tested alloys showed a clearly limited resistance against pitting corrosion phenomena. However, the best corrosion behaviour is shown by HASTELLOY C4, which has of all tested alloys the lowest passivation current density and the largest potential region with protection against local corrosion phenomena. (author)

  12. Electric field effect on formation of gas-circulation coatings on heat resistant alloy

    International Nuclear Information System (INIS)

    The experimental data for electric field effect on formation of gas-circulation coatings of ZhS-6U alloy are discussed. The effective influence of external electric pulses on the process at the temperature near to ?-phase dissolution in the alloy is shown. Possibility of multicomponent coating deposition (NiCrAlY) using electric bias is discussed. 4 refs., 3 figs

  13. Using of hot hydropressing of titanium and heat resisting alloys to prepare structure for superplastic deformation

    International Nuclear Information System (INIS)

    Considered are the main principles of superplastic deformation and the methods of preparing a fine-grained struture in titanium and refractory alloys for superelastic deformation. A description is given of hydraulic pressing using glass-graphite working media. It is shown that the blank heating temperature preparatory to hydraulic pressina mUst not exceed the limits of the temperature range of dissolution of ?'-phase which is the stabilizer of the fine-grained structure. The hydraulic pressing conditions for titanium alloys are worked out using the VT9 alloy. With the manufacture of turbine blade blanks from the ZhS6KP alloy as an example, the advantages are illustrated of the hot hydraulic pressing for profiling the blanks prior to forging

  14. Influence of a simulated HTGR environment on the mechanical properties of a commercial Ni-Cr-Mo-Fe alloy (Hastelloy Alloy X)

    International Nuclear Information System (INIS)

    The influence of a simulated advanced-reactor helium environment, containing 500 ?atm H2/50 ?atm CH4/50 ?atm CO/approx. 1 ?atm H2O, on the mechanical properties of two heats of Hastelloy Alloy X is discussed. Simultaneous exposures in air and controlled-impurity helium at temperatures in the range of 6500 to 10000C for times of 3000 h or more were performed. A combination of tensile testing, Charpy V-notch impact toughness testing, and creep testing was used to study the effects of reactor helium/metal interactions on the mechanical behavior of this alloy. Carburization was identified as the primary corrosion phenomenon. Increasing exposure time and temperature were observed to increase the depth of carburization. The increase in carbon concentration in the carburized zone suppressed the additional formation of M6C, which is observed in air-aged specimens, and resulted in the precipitation of M23C6, a chromium-rich carbide variant. The precipitation of M23C6 in the carburized zone occurred primarily along grain and twin boundaries; however, matrix precipitation was also observed, the degree of which depended on exposure temperature. Strength and impact toughness properties were found to be controlled primarily by thermal aging reactions, with only a small effect related to the carburization. Although tensile and creep ductilities were decreased as a result of carburization, substantial ductility remained. Variation was observed between the two heats, the finer-grained heat appearing to be weaker in the high-temperature creep tests and also possibly more susceptible to a loss of creep strength as a result of carburization

  15. Behaviour of selected heat resistant nickel-base alloys for steam turbine bolting

    International Nuclear Information System (INIS)

    The objective of the project was to optimize nickel-base turbine bolting by different heat treatments. The aim was to obtain the best comprise of the relevant bolting properties such as creep and relaxation strength, notch-rupture insensitivity, contraction and stress corrosion cracking-intensitivity. The investigations were carried out on the three creep-resistant nickel-base alloys NiCr 20Fe 25 TiAl (similar to Nimonic 70), NiCr 20 TiAl (corresponding to Nimonic 80A) and NiCr 15 TiAl (corresponding to Inconel X-750). (orig./MM) With 63 figs., 15 tabs

  16. ?????-?????????? ?????????? ???????????? ???????? ?? ???????? ??????? ??? ?? ??????????? ????????? ??????? Ion-plasma technology of deposition heat-resistant coatings for GTE turbine blades from resistant nickel alloys

    Directory of Open Access Journals (Sweden)

    ?. ?. ???????

    2012-10-01

    Full Text Available ??????????????? ??????????? ????????? ??????????? ??????????? ???????? ? ?????????????? ??????????, ?????????? ?? ???????????????????? ?????-??????????????? ? ?????-?????????? ??????? ???????-??????????? ????????? ? ????????? ????????. ?????????? ?????????? ???????????? ????????????? ? ??????? ???????????? ??????? ?? ????????? ??????????? ???????.The possibility of obtaining heat-resistant coatings using “nano-technology” based on high-energy ion-implantation and ion-plasma methods, protective and strengthening treatment and coating. The results of the study the heat resistance and fatigue strength of parts made of nickel-base superalloys.

  17. Effects of composite scale on high temperature oxidation resistance of Fe-Cr-Ni heat resistant alloy

    Directory of Open Access Journals (Sweden)

    Wang Haitao

    2009-05-01

    Full Text Available Fe-Cr-Ni heat resistant alloys with aluminum and silicon addition, alone and in combination, were melted using an intermediate frequency induction furnace with a non-oxidation method. By the oxidation weight gain method, the oxidation resistances of the test alloys were determined at 1,200 ìC for 500 hours. According to the oxidation weight gains, the oxidation kinetic curves were plotted and the functions were regressed by the least squares method. The results show that the oxidation kinetic curves follow the power function of y = axb (a>0, 0

  18. Creep rupture properties under varying load/temperature conditions on a nickel-base heat-resistant alloy strengthened by boron addition

    International Nuclear Information System (INIS)

    A series of constant load and temperature creep rupture tests and varying load and temperature creep rupture tests was carried out on Hastelloy XR whose boron content level is 60 mass ppm at 900 and 1000degC in order to examine the behavior of the alloy under varying load and temperature conditions. The life fraction rule completely fails in the prediction of the creep rupture life under varying load and temperature conditions though the rule shows good applicability for Hastelloy XR whose boron content level is below 10 mass ppm. The modified life fraction rule has been proposed based on the dependence of the creep rupture strength on the born content level of the alloy. The modified rule successfully predicts the creep rupture life under the test conditions from 1000degC to 900degC. The trend observed in the tests from 900degC to 1000degC can be qualitatively explained by the mechanism that the oxide film which is formed during the prior exposure to 900degC plays the role of the protective barrier against the boron dissipation into the environment. (author)

  19. Experimental determination of the behaviour of heat-resisting alloys in complex atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Tachikart, M.M.; Armanet, F.; Beranger, G.; Davidson, J.H.; Coddet, C.

    1987-10-01

    Designers of industrial plants are often confronted with problems of high temperature corrosion in complex atmospheres. The selection and development of economically and technically viable new materials for such applications requires the use of experimental rigs capable of simulating as closely as possible the real operating conditions. With this aim, a new laboratory installation has been built, which enables precisely defined mixtures of up to four gases to be obtained (plus water vapour, if required). It is thus possible to fix the activities of O, H, C and S at the working temperature. The composition is monitored at various points in the rig, using a chromatograph. The first tests were carried out on three Fe-Cr-Ni alloys exposed to complex gas mixtures (CO/CH/sub 4//H/sub 2//H/sub 2/S) similar to those encountered in coal-gasification plant. The observations show that, due to the low oxygen partial pressures, the multi-layered scales are composed mainly of sulphides. These results are compared with predictions based on calculated thermodynamic phase stability diagrams.

  20. Effects of stress aging on changes in mechanical properties and microstructures of Hastelloy-X and Hastelloy-XR

    International Nuclear Information System (INIS)

    Mechanical property and Microstructural changes of Ni-base super alloys after aging with and without tensile stress were observed in the temperature range of 500-10000C for durations to 305 hr. The materials tested are Hastelloy-X and its modified heat (Hastelloy-XR). Changes of the mechanical properties are appreciably enhanced by the application of stress during the aging. The changes are interpreted in connection with microstructural changes due to the enhanced carbide precipitation caused by the stress aging. Commercial grade Hastelloy-X is found to be more influenced by the stress than Hastelloy-XR. (auth.)

  1. Development of Simultaneous Corrosion Barrier and Optimized Microstructure in FeCrAl Heat-Resistant Alloy for Energy Applications. Part 1: The Protective Scale

    Science.gov (United States)

    Pimentel, G.; Aranda, M. M.; Chao, J.; González-Carrasco, J. L.; Capdevila, C.

    2015-09-01

    Coarse-grained Fe-based oxide dispersion-strengthened (ODS) steels are a class of advanced materials for combined cycle gas turbine systems to deal with operating temperatures and pressures of around 1100°C and 15-30 bar in aggressive environments, which would increase biomass energy conversion efficiencies up to 45% and above. This two-part paper reports the possibility of the development of simultaneous corrosion barrier and optimized microstructure in a FeCrAl heat-resistant alloy for energy applications. The first part reports the mechanism of generating a dense, self-healing ?-alumina layer by thermal oxidation, during a heat treatment that leads to a coarse-grained microstructure with a potential value for high-temperature creep resistance in a FeCrAl ODS ferritic alloy, which will be described in more detail in the second part.

  2. Characteristics and experimental evaluation of super-heat-resisting Nb-based and Mo-based alloys

    International Nuclear Information System (INIS)

    Nb-based and Mo-based alloys have been investigated in order to develop the frontiers of materials technique which will be utilized in the environment of high-temperature liquid alkali metals. In this study, both mechanical properties and corrosion resistance to liquid Li were evaluated for two designed Mo-based alloys, Mo-15Re-0.1Zr and Mo-15Re-0.1Zr-0.1Ti. In addition, a series of corrosion test was performed with provisionally designed Nb-based alloys, Nb-(1-4)Hf. High-temperature tensile properties: The designed Mo-based alloys were found to have more excellent high-temperature tensile properties, compared to the commercial TZM alloy. High-temperature creep properties: The designed Mo-based alloys were superior in the high-temperature creep properties to other solid solution hardening Mo-based alloys. Workability: The designed Mo-based alloys exhibited an excellent workability, irrespective of the Ti addition. Corrosion resistance to liquid Li: The Nb-1Hf alloy was chosen as a promising alloy of having the highest corrosion resistance among the Nb-based alloys. Also, the Mo-15Re-0.1Zr-0.1Ti alloy was superior to Mo-15Re-0.1Zr alloy, in view of the corrosion resistance to liquid Li. (J.P.N.)

  3. A study on the creep properties more over 700 C of advanced heat resistant carbon, nitrogen and cobalt free alloys

    Energy Technology Data Exchange (ETDEWEB)

    Muneki, Seiichi; Okubo, Hiroshi; Abe, Fujio [National Institute for Materials Science (NIMS) (Japan)

    2008-07-01

    A new attempt has been demonstrated using carbon, nitrogen and cobalt free Fe-12Ni-5Cr-Mo alloys strengthened by Laves phase such as Fe{sub 2}Mo to achieve creep deformation at high temperatures and high stress levels. Creep resistance of Fe-12Ni-5Cr-5Mo-0.005B alloys remarkably increased at elevated temperatures over 700 C. As the transformation temperatures of A{sub c1} and A{sub c3} of these alloys indicated remarkably low, the microstructure of these alloys was reverted austenite during the creep test over 700 C. Creep properties were extremely improved more over 700 C by the addition of boron, which depends on the effect of retardation of the recovery process and that the suppression of recrystallization of these alloys. Creep life of the Fe-12Ni-5Cr-10Mo-0.2Ti-0.1Al-0.005B alloy was drastically extended from 13h at 700 C and 300MPa to 2,100h at 700 C and 200MPa. Creep resistance in the Fe-12Ni alloys depends on the unrecrystallized austenite structure and a fine and uniform distribution of precipitates during creep tests. And that long term stability of microstructure works on the DSS operation effectively in the USC power plant. (orig.)

  4. Influence of the brazing parameters on microstructure and mechanical properties of brazed joints of Hastelloy B2 nickel base alloy; Influencia de los parametros de soldeo fuerte en la microestructura y propiedades mecanicas de la union de la aleacion base niquel Hastelloy B2

    Energy Technology Data Exchange (ETDEWEB)

    Sotelo, J. C.; Gonzalez, M.; Porto, E.

    2014-07-01

    A study of the high vacuum brazing process of solid solution strengthened Hastelloy B2 nickel alloy has been done. A first stage of research has focused on the selection of the most appropriate brazing filler metal to the base material and vacuum furnace brazing process. The influence of welding parameters on joint microstructure constituents, relating the microstructure of the joint to its mechanical properties, has been evaluated. Two gaps of 50 and 200 micrometers, and two dwell times at brazing temperature of 10 and 90 minutes were studied. The braze joint mainly consists of the nickel rich matrix, nickel silicide and ternary compounds. Finally, the results of this study have shown the high bond strength for small gaps and increased dwell times of 90 minutes. (Author)

  5. Fixed time integration-emission spectrochemical analysis of nickel-base alloys and heat resisting steels for minor amount of elements

    International Nuclear Information System (INIS)

    The emission spectrochemical analysis of nickel-base alloys and heat resisting steels by the fixed time integration method has been developed. Nickel contents of 9 to 76% in the samples were examined in this study. For such samples, the internal standard method was inadequate, while the fixed time integration method gave good accuracy in the determination of minor elements in these samples. Elements analysed were C, P, S, B, Si, Ta, Co, Fe, Mn, Nb, Cu, Ti, Zr and Al. At first, ternary alloys containing a constant amount of cobalt (0.5, 1.0, 3.0, 6.0, 10.0, or 20.0%) with changing amounts of nickel and iron were prepared in order to examine the effect of nickel and iron content on the determination of these elements. It was found that the samples should be classified to two groups according to the nickel content, that is one group corresponding to 9 - 60% nickel and the other to 60 - 76%, and calibration curves had to be made separately. The equations of calibration curves were given in the regression lines of the first order in the determination of minor elements. For correcting the effect of neighbouring lines, coefficients of correction were derived by the multiple regression analysis. The relation between the sensitivity of analysis and the coefficient of correction was examined. As the sensitivity, the gradient of calibration curves was chosen, and it was observed that there was a linear correlation between the gradient and the partial regression coefficient. After all, the relation of hyperbola was concluded to exist between the gradient and the coefficient of correction in the determination of most elements. The gradients of calibration curves in the two groups were almost the same, but the gradients of the group containing more amount of nickel were a little larger than those of the other. (author)

  6. Fundamental studies on electron beam welding of heat-resistant superalloys for nuclear plants, (1)

    International Nuclear Information System (INIS)

    The basic investigation and research on the multi-purpose utilization of nuclear reactors have been carried out as the national project. The equipments for high temperature gas-cooled reactors are exposed to severe conditions in helium atmosphere of 1000 deg C, therefore the use of heat-resistant alloys such as Hastelloy, Inconel and Incoloy has been examined. The electron beam welding recently expanding the fields of application has excellent properties, such as the energy density is very high, the power output can be controlled freely as occasion arises, deep penetration can be obtained with small heat input, welding of high precision is feasible because the width of weld is narrow and the distortion due to the welding is small, and the weld of good quality can be obtained as the welding is carried out in vacuum. However, when the welding conditions are improper, the defects peculiar to electron beam welding arise, such as porosity, cold shut, spike phenomenon, and cracking due to welding. In this study, the characteristics of weld beads of respective heat-resistant alloys, especially the penetration mode and the properties of defects, were investigated by changing the parameters of electron beam welding, and the correlation among these was discussed. The range of proper welding conditions was set up for respective materials. Moreover, the correlation among the cracking susceptibility due to electron beam welding, the high temperature ductility of materials and the results of Trans-Varestraint test was investigated, and these testing methods are very useful for the evaluation of cracking susceptibility. (Kako, I.)

  7. Influence of temperature, environment, and thermal aging on the continuous cycle fatigue behavior of Hastelloy X and Inconel 617

    International Nuclear Information System (INIS)

    Results are presented for strain-controlled fatigue and tensile tests for two nickel-base, solution-hardened reference structural alloys for use in several High-Temperature Gas-Cooled Reactor (HTGR) concepts. These alloys, Hastelloy X and Inconel 617, were tested from room temperature to 8710C in air and impure helium. Materials were tested in both the solution-annealed and the preaged conditios, in which aging consisted of isothermal exposure at one of several temperatures for periods of up to 20,000 h. Comparisons are given between the strain-controlled fatigue lives of these and several other commonly used alloys, all tested at 5380C. An analysis is also presented of the continuous cycle fatigue data obtained from room temperature to 4270C for Hastelloy G, Hastelloy X, Hastelloy C-276, and Hastelloy C-4, an effort undertaken in support of ASME code development

  8. Time-dependent high-temperature low-cycle fatigue behavior of nickel-base heat-resistant alloys for HTGR

    International Nuclear Information System (INIS)

    A series of strain controlled low-cycle fatigue tests at 900 deg C in the simulated HTGR helium environment were conducted on Hastelloy X and its modified version, Hastelloy XR in order to examine time-dependent high-temperature low-cycle fatigue behavior. In the tests with the symmetric triangular strain waveform, decreasing the strain rate led to notable reductions in the fatigue life. In the tests with the trapezoidal strain waveform with different holding types, the fatigue life was found to be reduced most effectively in tensile hold-time experiments. Based on the observations of the crack morphology the strain holding in the compressive side was suggested to play the role of suppressing the initiation and the growth of internal cracks or cavities, and to cause crack branching. When the frequency modified fatigue life method and/or the prediction of life by use of the ductility were applied, both the data obtained with the symmetric triangular strain waveform and those with the tensile hold-time experiments lay on the straight line plots. The data, however, obtained with the compressive and/or both hold-time experiments could not be handled satisfactorily by those methods. When the cumulative damage rule was applied, it was found that the reliability of HTGR components was ensured by limiting the creep-fatigue damage fraction within the value of 1. (author)

  9. Grain growth in heat resisting austenitic steels

    Energy Technology Data Exchange (ETDEWEB)

    Denisova, I.K.; Zakharov, V.N.; Karpova, N.M.; Farber, V.M.

    1985-01-01

    A study was made on kinetics of grain growth in steels of 37Kh12N8G8 type alloyed by V, Nb, Ti, Mo, W. It was concluded that the nature of carbide phase and kinetics of its dissolution in heat resisting austenitic steels dictate steel tendency to grain growth. At the same time decrease of diffusion mobility of atoms in steel matrix during its alloying by titanium aid tungsten results in sufficient decrease of the tendency to grain growth and variation in grain size.

  10. High temperature low-cycle fatigue strength of Hastelloy-XR

    International Nuclear Information System (INIS)

    This paper describes the low-cycle fatigue and creep-fatigue interaction properties of Hastelloy-XR in air and helium containing a small quantity of impurity gas. All tests at temperatures of 700, 800, 900 and 1000 deg. C are carried out at the strain rate of 0.1 and 0.01%/sec under the control of axial strain. Wave forms are triangular for continuous cycling tests and trapezoidal for tension hold time tests. The test results are compared with the fatigue property of Hastelloy-X which is the original alloy of Hastelloy-XR. The applicability of linear damage rule in ASME Code Case N-47 is discussed about creep-fatigue interaction property of Hastelloy-XR in High Temperature Gas-Cooled Reactor's temperature region. (author). 6 refs, 7 figs, 2 tabs

  11. Nickel Alloy, Corrosion and Heat-Resistant, Sheet, Strip, and Plate 72Ni - 15.5Cr - 0.95 (Cb (Nb) + Ta) - 2.5Ti - 0.70Al - 7.0Fe Consumable Electrode, Remelted or Vacuum Induction Melted, Solution Heat Treated, Precipitation-Hardenable

    CERN Document Server

    SAE Aerospace Standards. London

    2012-01-01

    Nickel Alloy, Corrosion and Heat-Resistant, Sheet, Strip, and Plate 72Ni - 15.5Cr - 0.95 (Cb (Nb) + Ta) - 2.5Ti - 0.70Al - 7.0Fe Consumable Electrode, Remelted or Vacuum Induction Melted, Solution Heat Treated, Precipitation-Hardenable

  12. The new alloy Thermon 4972 (NiCr22W12Fe) for high temperature components of gas-cooled reactors

    International Nuclear Information System (INIS)

    A new heat resistant Fe-Ni-Cr-W alloy - Thermon 4972 - was developed within the scope of the prototype nuclear process plant project. This new alloy not only shows mechanical properties and creep rupture properties similar to those of the nickel-based alloy Inconel 617 but in addition, the new alloy forms protective oxide layers in atmospheres with very low O2 partial pressures. Experimental test results carried out in so called PNP-helium for durations up to 2000 h in the temperature range of 750 and 950 deg. C are compared with those of the alloy Inconel 617. Furthermore the mechanical properties of these two alloys as also the alloys Hastelloy X and Incoloy 800 H have been compared. (author). 5 refs, 18 figs, 2 tabs

  13. Integral semispheric emissivity and specific electric resistance of Kh20N80 and KhN45V30 heat resisting alloys

    International Nuclear Information System (INIS)

    The results of the investigation of the integral semispherical blackness factor and specific electric resistance of Kh20N80 and KhN45V30 alloys, which are very prospective for use in fuel rods, in the temperature range from 1000 to 1650 K are presented. When both alloys are heated above 1000 K in a vacuum of 1x10-4 mm Hg, an irreversible increase of radiative power is observed associated with oxidation of chromium. The integral semi-spherical blackness factor of oxidized surface of Kh20N80 alloy is in the range from 0.7 to 0.75, but irreversibly decreases in a vacuum of 1x10-4 mm Hg and at T > 1500 K due to the destruction of the protecting oxide film. More stable oxide phases formed on the KhN45V30 alloy under heating in open air and vacuum of 1x10-4 mm Hg are responsible for the high radiative power of the oxidized surface (epsilon = 0.8 to 0.85) observed up to alloy's melting point. The specific electric resistance of both alloys varies insignificantly in the temperature range considered, being somewhat lower in the KhN45V30 alloy

  14. Application of Hastelloy X in Gas-Cooled Reactor Systems

    DEFF Research Database (Denmark)

    Brinkman, C. R.; Rittenhouse, P. L.

    1976-01-01

    Hastelloy X, an Ni--Cr--Fe--Mo alloy, may be an important structural alloy for components of gas-cooled reactor systems. Expected applications of this alloy in the High-Temperature Gas-Cooled Reactor (HTGR) are discussed, and the development of interim mechanical properties and supporting data are reported. Properties of concern include tensile, creep, creep-rupture, fatigue, creep-fatigue interaction, subcritical crack growth, thermal stability, and the influence of helium environments with controlled amounts of impurities on these properties. In order to develop these properties in helium environments that are expected to be prototypic of HTGR operating conditions, it was necessary to construct special environmental test systems. Details of construction and operating parameters are described. Interim results from tests designed to determine the above properties are presented. To date a fairly extensive amount of information has been generated on this material at Oak Ridge National Laboratory and elsewhere concerning behavior in air, which is reviewed. However, only limited data are available from tests conducted in helium. Comparisons of the fatigue and subcritical growth behavior in air between Hastelloy X and a number of other structural alloys are given.

  15. Composition of eta carbide in Hastelloy N after aging 10,000 hr at 8150C

    International Nuclear Information System (INIS)

    The composition of the eta carbide in Hastelloy N containing 0.7 wt percent Si in the alloy approaches M12C, rather than M6C as indicated in the alloy literature. The silicon content of the eta phase in this case was about 25 at. percent, much higher than has been observed in less highly alloyed material. The data do not permit a definition of the limiting compositions of the phases

  16. Effect of temperature upon the fatigue-crack propagation behavior of Hastelloy X-280

    International Nuclear Information System (INIS)

    The techniques of linear-elastic fracture mechanics were employed to characterize the effect of temperature upon the fatigue-crack propagation behavior of Hastelloy X-280 in an air environment. Also included in this study are survey tests to determine the effects of thermal aging and stress ratio upon crack growth behavior in this alloy

  17. Kinetics of evaporation from the surface of refractory nickel and titanium alloys with heat resistant coatings during their irradiation by high-power pulsed ion beams

    International Nuclear Information System (INIS)

    The effect of the irradiating conditions by high-power pulsed ion beams (HPPIB) on the ablation rate was studied. The conditions of irradiation (ions of carbon and protons, ion energy E=300-600 keV, the ion current density in a pulse j=60-500 A·cm-2, pulse duration ?=50-100 ns) were realized in 'Temp' and 'Vera' accelerators. The study of the evaporation kinetics was carried out using targets manufactured from GS26NK nickel super-alloy with NiCrAlY coating and from Vt9 and VT18U titanium alloys with Zr N and TiSiB coatings. It is shown that values of the ablation rate achieve 0.04 ?m (TiSiB), 0.4 ?m (NiCrAlY), and 1 ?m (Zr N) during a pulse under the optimal conditions of HPPIB irradiation

  18. Creep properties of 20% cold-worked Hastelloy XR

    International Nuclear Information System (INIS)

    The creep properties of Hastelloy XR, in solution-treated and in 20% cold-worked conditions, were studied at 800, 900 and 1000 C. At 800 C, the steady-state creep rate and rupture ductility decrease, while rupture life increases after cold work to 20%. Although the steady-state creep rate and ductility also decrease at 900 C, the beneficial effect on rupture life disappears. Cold work to 20% enhan ces creep resistance of this alloy at 800 and 900 C due to a high density of dislocations introduced by the cold work. Rupture life of the 20% cold-worked alloy becomes shorter and the steady-state creep rate larger at 1000 C during creep of the 20% cold-worked alloy. It is emphasized that these cold work effects should be taken into consideration in design and operation of high-temperature structural components of high-temperature gas-cooled reactors. (orig.)

  19. Development of Simultaneous Corrosion Barrier and Optimized Microstructure in FeCrAl Heat-Resistant Alloy for Energy Applications. Part II: The Optimized Creep-Resistant Microstructure

    Science.gov (United States)

    Pimentel, G.; Aranda, M. M.; Chao, J.; González-Carrasco, J. L.; Capdevila, C.

    2015-09-01

    The first part of this two-part study reported the possibility of simultaneously generating a dense, self-healing ?-alumina layer by thermal oxidation and a coarse-grained microstructure with a potential goodness for high-temperature creep resistance in a FeCrAl oxide dispersion-strengthened ferritic alloy that was cold deformed after hot rolling and extrusion. In this second part, the factors affecting the formation of the coarse-grained microstructure such as strain gradients induced during the rolling process are analyzed. It is concluded that larger strain gradients lead to more refined and more isotropic grain structures.

  20. The flow behavior modeling of as-extruded 3Cr20Ni10W2 austenitic heat-resistant alloy at elevated temperatures considering the effect of strain

    Scientific Electronic Library Online (English)

    Guo-Zheng, Quan; Yuan-Ping, Mao; Chun-Tang, Yu; Wen-Quan, Lv; Jie, Zhou.

    2014-04-01

    Full Text Available In order to investigate the compressive deformation behavior of 3Cr20Ni10W2 alloy, a series of isothermal upsetting experiments were carried out in the temperature range of 1203-1403 K and strain rate range of 0.01-10 s-1 on a Gleeble-1500 thermo-mechanical simulator. The results indicate that the f [...] low stress initially increases to a peak value and then decreases gradually to a steady state. The characteristics of the curves are determined by the interaction of work hardening (WH), dynamic recovery (DRV) and dynamic recrystallization (DRX). The flow stress decreases with increasing temperature and decreasing strain rate. The relationship between microstructure and processing parameters is discussed to give an insight into the hot deformation behavior of 3Cr20Ni10W2 alloy. Then, by regression analysis for constitutive equation, material constants (n, ?, ?, A and Q) were calculated for the peak stress. Further, the constitutive equation along the flow curve was developed by utilizing an eighth order polynomial of strain for variable coefficients (including n, ?, A and Q). The validity of the developed constitutive equation incorporating the influence of strain was verified through comparing the experimental and predicted data by using standard statistical parameters such as correlation coefficient (R) and average absolute relative error (AARE) that are 0.995 and 4.08% respectively.

  1. Corrosion behavior of Hastelloy C-276 in supercritical water

    International Nuclear Information System (INIS)

    The corrosion behavior of a nickel-based alloy Hastelloy C-276 exposed in supercritical water at 500-600 deg. C/25 MPa was investigated by means of gravimetry, scanning electron microscopy/energy dispersive X-ray spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. An oxide scale with dual-layer structure, mainly consisting of an outer NiO layer and an inner Cr2O3/NiCr2O4-mixed layer, developed on C-276 after 1000 h exposure. Higher temperature promoted oxidation, resulting in thicker oxide scale, larger weight gain and stronger tendency of oxide spallation. The oxide growth mechanism in SCW seems to be similar to that in high temperature water vapor, namely solid-state growth mechanism.

  2. Weldability of the superalloys Haynes 188 and Hastelloy X by Nd:YAG

    OpenAIRE

    Graneix Jérémie; Beguin Jean-Denis; Pardheillan François; Alexis Joël; Masri Talal

    2014-01-01

    The requirements for welded aircraft parts have become increasingly severe, especially in terms of the reproducibility of the geometry and metallurgical grade of the weld bead. Laser welding is a viable method of assembly to meet these new demands, because of automation, to replace the manual TIG welding process. The purpose of this study is to determine the weldability of Hastelloy X and Haynes 188 alloys by the butt welding process with a Nd:YAG laser. To identify the influential parameters...

  3. Alloys For Flexible Hoses In A Corrosive Environment

    Science.gov (United States)

    Macdowell, Louis G., III; Ontiveros, Cordelia

    1992-01-01

    High-nickel alloy resists pitting corrosion. Report evaluates metal alloys for flexible hoses in corrosive environment. Tested to find alternatives to 304L stainless steel. Nineteen alloys selected for testing on basis of reputation for resistance to corrosion. Top five, in order of decreasing resistance to corrosion: Hastelloy(R) C-22, Inconel(R) 625, Hastelloy(R) C-276, Hastelloy(R) C-4, and Inco(R) alloy G-3. Of these, Hastelloy(R) C-22 found best for flexible-hose application.

  4. Technology and application of heat resistant concretes

    International Nuclear Information System (INIS)

    Theoretical grounds for creating heat resistant concretes are reviewed, potential application of concretes at high temperatures is established as well as the principles for calculating and designing thermal assemblies of heat resistant concretes, preparation procedure, placing and operation of linings made of these concretes. It is shown that nowadays all necessary scientific and technological prerequisites are created for a wide application of thermal units and structures made of heat resistant concretes and reinforced concretes operating under conditions of elevated and very high temperatures. These prerequisites comprise the development of compositions of heat resistant concretes to be used in a wide temperature range (200-1700 deg C), procedure of industrial production, scientifically based principles of designing and calculating heat-resistant concrete- and reinforced concrete structures and appropriate standard documentation

  5. Creep properties and simulation of weld repaired low alloy heat resistant CrMo and Mo steels at 540 deg C. Sub project 1 - Ex-serviced parent metal and virgin weld metals

    Energy Technology Data Exchange (ETDEWEB)

    Rui Wu; Storesund, Jan; Borggreen, Kjeld; Weilin Zang

    2006-10-15

    Many existing power generating and process plants, where low alloy heat resistant CrMo(V) steels are extensively used for critical components, have exceeded their design lifetime of usually 100,000 hours. Assessment of residual lifetime and extension of economic life by weld repair have become increasingly important and attractive. This project aims at i) performing weld repair and determining the degree of mismatching, ii) evaluating the creep properties of weld repairs, iii) analysing creep behaviour of weld repair and providing necessary data for further reliable simulations of weld repair creep behaviour in long term service, and iv), simulating and assessing lifetime and creep damage evolution of weld repair. Weld repair using 10 CrMo 9 10, 13 CrMo 4 4 and 15 Mo 3 consumables has been carried out in a service-exposed 10 CrMo 9 10 pipe. Creep specimens have been extracted from the service-exposed 10 CrMo 9 10 parent metal (PM), from the virgin 10 CrMo 9 10 weld metal (WM), from the virgin 13 CrMo 4 4 WM as well as from the virgin 15 Mo 3 WM. Iso-thermal uniaxial creep tests have been performed at 540 deg C in air. Pre- and post-metallography are carried out on the selected samples. FEM simulations using obtained creep data are executed. Pre-test metallography shows normal and acceptable weld repairs at given welding conditions. Creep tests demonstrate that the virgin 10 CrMo 9 10, 13 CrMo 4 4 and 15 Mo 3 WMs have apparently longer creep lifetime than the service-exposed CrMo 9 10 PM at higher stresses than 110 MPa. Among the weld metals, the longest creep lifetime is found in 10 CrMo 9 10. Higher creep strength and lower creep strain rate in the weld metals indicate an overmatch weld. At 95 MPa, however, lifetime of 13 CrMo 4 4 WM is surprisingly short (factors which may shorten lifetime are discussed and one more test will start to verify creep strength at low stress) and tests are still running for other two weld metals. More results regarding low stress creep behaviour will therefore be available at phase 2 of the project. Together with the results of creep tests on the crosswelds and simulations, concrete conclusions and recommendations will be also given at phase 2 of the project. Transgranular failure is predominant, independent of stresses and materials. Pores/cavities are only found adjacent to the fracture. FEM simulations using obtained creep data predict fracture in corresponding weld metal. Extrapolation of the creep results to service stress, i.e. 35 MPa, results in undermatched welds for repairs with 13 CrMo 4 4 and 15 Mo 3 weld metals. Norton's law, Monkman-Grant relation and {phi}- and {omega}-models (strain-strain rate) are valid for both parent and weld metals. These models can be utilised for lifetime assessment and reproduction of creep curves. Using {phi}- and {omega}-models, creep curves have been successfully reproduced and the reproduced creep curves are comparative with the experiments. Creep tests on the weld metals at low stress as well as on cross-weld specimens at phase 2 of the project are expected to provide more results, comprehensive understanding of creep behaviour in weld repair as a whole and reliable simulations.

  6. Hydrogen permeation of Hastelloy XR for high temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Hydrogen permeation of Hastelloy XR, which was developed for high-temperature gas-cooled reactors, has been investigated with a simulated gas to the reactor environment, 80% H2+15% CO+15% CO+5% CO2. In this gas environment, Hastelloy XR formed chromium oxide and manganese-spinel oxide on the surface and showed a good quality to prevent hydrogen permeation. The prevention behavior can be interpreted in terms of a hydrogen diffusion model in a uniform oxide layer, and dependences of permeation rate on time and temperature are explained by variation of oxide thickness. The pressure dependence of the permeation rate for the oxidized alloy as well as bare metals obeyed Sieverts' law. The environmental effects on hydrogen permeation are also discussed on the basis of correlation between the characteristics of the surface layer and the permeation behaviors. (orig.)

  7. Disk-laser welding of Hastelloy X cover on René 80 turbine stator blade

    Science.gov (United States)

    Caiazzo, Fabrizia; Corrado, Gaetano; Alfieri, Vittorio; Sergi, Vincenzo; Cuccaro, Luigi

    2012-01-01

    Nickel-base alloys, such as Hastelloy X and René 80, are among the most common ones for aerospace applications, due to their mechanical strength at high temperatures and oxidation resistance properties, although processing for missile and space vehicle applications requires extensive fusion and resistance welding for fastening. Laser welding using a Yb:YAG disk laser in continuous mode emission is investigated in this paper for overlap joining of Hastelloy X plates on René 80 samples resulting from waste turbine blades. An explorative study is carried out in order to find an appropriate processing window as well as discussing bead features and common issues. Special fixtures for clamping have been specifically developed and tested. A 3-factors study with power, welding speed and focus position as governing parameters has been arranged; 2 levels have been chosen for each factor. Geometric features, defects and indications are discussed referring to the parameters main effects.

  8. Evaluation of Heat Checking and Washout of Heat Resistant Superalloys and Coatings for Die inserts

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Yulong Zhu; Edward Courtright; Harold Adkins

    2005-01-30

    This project had two main objectives: (1) To design, fabricate and run a full size test for evaluating soldering and washout in die insert materials. This test utilizes the unique capabilities of the 350 Ton Squeeze Casting machine available in the Case Meal Casting Laboratory. Apply the test to evaluate resistance of die materials and coating, including heat resistant alloys to soldering and washout damage. (2) To evaluate materials and coatings, including heat resistant superalloys, for use as inserts in die casting of aluminum alloys.

  9. Plasma treatment of heat-resistant materials

    Science.gov (United States)

    Vlasov, V. A.; Kosmachev, P. V.; Skripnikova, N. K.; Bezukhov, K. A.

    2015-11-01

    Refractory lining of thermal generating units is exposed to chemical, thermal, and mechanical attacks. The degree of fracture of heat-resistant materials depends on the chemical medium composition, the process temperature and the material porosity. As is known, a shortterm exposure of the surface to low-temperature plasma (LTP) makes possible to create specific coatings that can improve the properties of workpieces. The aim of this work is to produce the protective coating on heat-resistant chamotte products using the LTP technique. Experiments have shown that plasma treatment of chamotte products modifies the surface, and a glass-ceramic coating enriched in mullite is formed providing the improvement of heat resistance. For increasing heat resistance of chamotte refractories, pastes comprising mixtures of Bacor, alumina oxide, and chamot were applied to their surfaces in different ratios. It is proved that the appropriate coating cannot be created if only one of heat-resistant components is used. The required coatings that can be used and recommended for practical applications are obtained only with the introduction of powder chamot. The paste composition of 50% chamot, 25% Bacor, and 25% alumina oxide exposed to plasma treatment, has demonstrated the most uniform surface fusion.

  10. Multiscale modeling and experiment validation of microstructure evolution induced by Ar+ irradiation in hastelloy C276

    International Nuclear Information System (INIS)

    The microstructure evolution induced by Ar+ irradiation (room temperature, about 10 dpa) in nickel based alloy Hastelloy C276 was studied using molecular dynamics and cluster dynamics, and a multiscale modeling code Radieff was constructed based on rate theory. The nucleation and growth of interstitial dislocation loops and void were studied by Radieff code. C276 was irradiated by 115 keV Ar+ at room temperature as validation experiment using transmission electron microscope (TEM)-implanter/accelerator interface facility at Wuhan University, and the microstructure evolution was observed by TEM. The size of dislocation loops simulated by Radieff is in good agreement with experiment. (authors)

  11. Application of newly developed heat resistant materials for USC boilers

    International Nuclear Information System (INIS)

    This paper describes the research on the development and improvement of new high strength heat resistant steels such as SUPER304H (18Cr-9Ni-3Cu-Nb-N), NF709 (20Cr-25Ni-1.5Mo-Nb-Ti-N) and HR3C (25Cr-20Ni-Nb-N) as boiler tube, and NF616 (9Cr-0.5Mo-1.8W-Nb-V) and HCM12A (11Cr-0.4Mo-2W-Nb-V-Cu) as thick section pipe. The latest manufacturing techniques applied for these steels are introduced. In addition the high temperature strength of Alloy617 (52Ni-22Cr-13Co-9Mo-Ti-Al) that is one of the candidate materials for the next generation 700 ? USC boilers is described. (orig.)

  12. Heat resistance of juice spoilage microorganisms.

    Science.gov (United States)

    Shearer, Adrienne E H; Mazzotta, Alejandro S; Chuyate, Rolenda; Gombas, David E

    2002-08-01

    The heat resistance of various yeasts (Saccharomyces cerevisiae, Rhodotorula mucilaginosa, Torulaspora delbrueckii, and Zygosaccharomyces rouxii), molds (Penicillium citrinum, Penicillium roquefortii, and Aspergillus niger), and lactic acid bacteria (Lactobacillus fermentum and Lactobacillus plantarum) obtained from spoiled acid or acidified food products was determined in 0.1 M citrate buffer at pH values of 3.0, 3.5, and 4.0. S. cerevisiae was the most heat resistant of the microorganisms in citrate buffer, and its heat resistance was further evaluated in apple, grapefruit, calcium-fortified apple, and tomato juices as well as in a juice base with high fructose corn syrup. Decimal reduction times (D-values) and changes in temperature required to change the D-value (z-values) for S. cerevisiae were higher in the juices than in citrate buffer at all pH values tested. The D57 degrees C(135 degrees F)-values varied from 9.4 min in the juice product with pH 2.8 to 32 min in a calcium-added apple juice with pH 3.9. The S. cerevisiae strain used in this study can be used in thermal-death-time experiments in acidic products to calculate process conditions and in challenge tests to validate the calculated temperatures and hold times during processing. PMID:12182479

  13. CORN CULTIVAR IDENTIFICATION THROUGH HEAT RESISTANT PROTEINS

    Directory of Open Access Journals (Sweden)

    SOLANGE CARVALHO BARRIOS ROVERI JOSÉ

    2004-04-01

    Full Text Available Stable and polymorphic markers are required for the identification and registration of the cultivars. The purpose of this research was to evaluate the heat resistant proteins polymorphism and stability of seeds from corn lines harvested in different years and dried under natural and artificial conditions, in order to employ such proteins in the identification and registration of the cultivars. The seeds showed different physiological quality when evaluated by germination test and the heat resistant proteins were extracted from embryonic axis from seeds of each line, in Tris-HCl 0,05 M buffer. The eletrophoretic patterns of these proteins in SDS-PAGE showed stable bands for each genotype even for the lines with higher variation in the germination test. The most similar corn inbred lines were distinguished, at least by two bands, showing that these proteins were highly polymorphic. The stability and the high level of polymorphism of the heat resistant proteins, make them potential markers in corn cultivars registration and identification programs.

  14. Flexible heat resistant neutron shielding resin

    Energy Technology Data Exchange (ETDEWEB)

    Sukegawa, Atsuhiko M., E-mail: morioka.atsuhiko@jaea.go.jp [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-machi, Ibaraki 311-0193 (Japan); Anayama, Yoshimasa [Neo-Tech R and D, 6-6-1, Ginza, Chuo-ku, Tokyo 104-0061 (Japan); Okuno, Koichi, E-mail: okunok@hazama.co.jp [Hazama Technical Research Institute, 515-1 Karima, Tsukuba-shi, Ibaraki 305-0822 (Japan); Sakurai, Shinji, E-mail: sakurai.shinji@jaea.go.jp [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-machi, Ibaraki 311-0193 (Japan); Kaminaga, Atsushi, E-mail: kaminaga.atsushi@jaea.go.jp [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-machi, Ibaraki 311-0193 (Japan)

    2011-10-01

    A flexible heat resistant neutron shielding material has been developed, which consists of polymer resin with 1 wt% boron. The neutron shielding performance of the developed resin, examined by the {sup 252}Cf neutron source, is almost the same as that of the polyethylene. The outgas of H{sub 2}, H{sub 2}O, CO and CO{sub 2} from the resin have been measured at {approx}250 deg. C environment. The resin will be applied around the port of the vacuum vessel as an additional shielding material and reduce the neutron streaming from a superconducting tokamak device such as JT-60SA.

  15. Flexible heat resistant neutron shielding resin

    Science.gov (United States)

    Sukegawa, Atsuhiko M.; Anayama, Yoshimasa; Okuno, Koichi; Sakurai, Shinji; Kaminaga, Atsushi

    2011-10-01

    A flexible heat resistant neutron shielding material has been developed, which consists of polymer resin with 1 wt% boron. The neutron shielding performance of the developed resin, examined by the 252Cf neutron source, is almost the same as that of the polyethylene. The outgas of H 2, H 2O, CO and CO 2 from the resin have been measured at ˜250 °C environment. The resin will be applied around the port of the vacuum vessel as an additional shielding material and reduce the neutron streaming from a superconducting tokamak device such as JT-60SA.

  16. Flexible heat resistant neutron shielding resin

    International Nuclear Information System (INIS)

    A flexible heat resistant neutron shielding material has been developed, which consists of polymer resin with 1 wt% boron. The neutron shielding performance of the developed resin, examined by the 252Cf neutron source, is almost the same as that of the polyethylene. The outgas of H2, H2O, CO and CO2 from the resin have been measured at ?250 deg. C environment. The resin will be applied around the port of the vacuum vessel as an additional shielding material and reduce the neutron streaming from a superconducting tokamak device such as JT-60SA.

  17. Effects of gaseous environments in gas-cooled reactors and solar thermal heat exchangers on the creep and creep-rupture properties of heat-resisting metals and alloys. Final report

    International Nuclear Information System (INIS)

    Energy conversion systems employing heat exchangers use closed cycle gas turbines with helium as the working fluid. An important design criterion for heat exchanger and turbine systems is the creep strength of the tubing, blading, and vane materials. The design data for these materials generally has been obtained in air. However, there have been reports of adverse environmental effects of helium on the creep strength and ductility of these materials. Much of the environmental data has been obtained using relatively impure helium from high temperature helium-cooled reactor systems (HTGR's). However, power conversion systems using coal or solar energy as the heat source would use commercially pure helium, not subject to the carbonaceous gases that are picked up when helium is used as the coolant for the HTGR's. Stanford University was asked to summarize the environmental effects of helium on the creep properties of heat exchanger alloys. Also, they were asked to conduct critical experiments under what ought to probably be the worst conditions, based on the literature, to determine the maximum extent of the environmental effect. It was found that the environmental effects reported in the literature are relatively small, not more than a factor of two in rupture time or creep rate, which is within the usual experimental scatter and in heat-to-heat variations. The experimental work reported on a HA188 confirmed this conclusion

  18. Machinability of hastelloy C-276 using Hot-pressed sintered Ti(C7N3)-based cermet cutting tools

    Science.gov (United States)

    Xu, Kaitao; Zou, Bin; Huang, Chuanzhen; Yao, Yang; Zhou, Huijun; Liu, Zhanqiang

    2015-05-01

    C-276 nickel-based alloy is a difficult-to-cut material. In high-speed machining of Hastelloy C-276, notching is a prominent failure mode due to high mechanical properties of work piece, which results in the short tool life and low productivity. In this paper, a newly developed Ti(C7N3)-based cermet insert manufactured by a hot-pressing method is used to machine the C-276 nickel-based alloy, and its cutting performances are studied. Based on orthogonal experiment method, the influence of cutting parameters on tool life, material removal rates and surface roughness are investigated. Experimental research results indicate that the optimal cutting condition is a cutting speed of 50 m/min, depth of cut of 0.4 mm and feed rate of 0.15 mm/r if the tool life and material removal rates are considered comprehensively. In this case, the tool life is 32 min and material removal rates are 3000 mm3/min, which is appropriate to the rough machining. If the tool life and surface roughness are considered, the better cutting condition is a cutting speed of 75 m/min, depth of cut of 0.6 mm and feed rate of 0.1 mm/r. In this case, the surface roughness is 0.59?m. Notch wear, flank wear, chipping at the tool nose, built-up edge(BUE) and micro-cracks are found when Ti(C7N3)-based cermet insert turned Hastelloy C-276. Oxidation, adhesive, abrasive and diffusion are the wear mechanisms, which can be investigated by the observations of scanning electron microscope and energy-dispersive spectroscopy. This research will help to guide studies on the evaluation of machining parameters to further advance the productivity of nickel based alloy Hastelloy C-276 machining.

  19. Heat resistance of Fe-Al intermetallics in the context of selected heat-resistant and hihg-temperature creep resistant steels

    Directory of Open Access Journals (Sweden)

    P. Baranowski

    2009-04-01

    Full Text Available Results are hereby presented of heat-resistance tests of two Fe3Al and FeAl intermetallic phase-based alloys in the context of St41k-typeboiler steel and 50H21G9N4 high-temperature creep resistant steel. It has been ascertained that heat resistance of the 50H21G9N4 steeland of the Fe3Al and FeAl intermetallic phase-based alloys significantly exceeds that of the boiler steel tested in the air atmosphere and the atmosphere of a flue gas with CO, CO2, SiO2 content alike. Improvement of these properties depends of exposure conditions. The largest differences have been observed when the tests were carried out in temperature 1023 K and in the flue gas atmosphere. The differences have been more and more noticeable as the exposition duration extended. A tendency has been also recorded of smaller mass decrements of the Fe3Al and FeAl intermetallic phase-based alloys as compared to the 50H21G9N4 steel.

  20. Compatibility of aluminide-coated Hastelloy x and Inconel 617 in a simulated gas-cooled reactor environment

    International Nuclear Information System (INIS)

    Commercially prepared aluminide coatings on Hastelloy X and Inconel 617 substrates were exposed to controlled-impurity helium at 8500 and 9500C for 3000 h. Optical and scanning electron (SEM) microscopy, electron microprobe profiles, and SEM X-ray mapping were used to evaluate and compare exposed and unexposed control samples. Four coatings were evaluated: aluminide, aluminide with platinum, aluminide with chromium, and aluminide with rhodium. With extended time at elevated temperature, nickel diffused into the aluminide coatings to form epsilon-phase (Ni3Al). This diffusion was the primary cause of porosity formation at the aluminide/alloy interface

  1. A new approach to raising heat resistance of epoxy nanocomposites

    Science.gov (United States)

    Korobko, Anatoliy P.; Levakova, Irina V.; Krasheninnikov, Sergey V.

    2012-07-01

    A new approach to enhancing heat resistance of epoxy nanocomposites is offered. Complete exfoliation of montmorillonite particles into individual platelets (nanoparticles) is not sufficient condition for increasing the glass transition temperature of the epoxy nanocomposite. A much higher contribution to the increase in the heat resistance is ensured by grafting of epoxy molecular chains onto the surface of aluminosilicate platelets.

  2. Long-term behaviour of heat-resistant steels and high-temperature materials

    International Nuclear Information System (INIS)

    This book contains 10 lectures with the following subjects: On the effect of thermal pretreatment on the structure and creep behaviour of the alloy 800 H (V. Guttmann, J. Timm); Material properties of heat resistant ferritic and austenitic steels after cold forming (W. Bendick, H. Weber); Investigations for judging the working behaviour of components made of alloy 800 and alloy 617 under creep stress (H.J. Penkalla, F. Schubert); Creep behaviour of gas turbine materials in hot gas (K.H. Kloos et al.); Effect of small cold forming on the creep beahviour of gas turbine blades made of Nimonic 90 (K.H. Keienburg et al.); Investigations on creep fatigue alternating load strength of nickel alloys (G. Raule); Change of structure, creep fatigue behaviour and life of X20 Cr Mo V 12 1 (by G. Eggeler et al.); Investigations on thermal fatigue behaviour (K.H. Mayer et al.); Creep behaviour of similar welds of the steels 13 Cr Mo 4 4, 14 MoV 6 3, 10 Cr Mo 910 and GS-17 Cr Mo V 5 11 (K. Niel et al.); Determining the creep crack behaviour of heat resistant steels with samples of different geometry (K. Maile, R. Tscheuschner). (orig.,/MM)

  3. Creep properties of Hastelloy X in a carburizing helium environment

    International Nuclear Information System (INIS)

    In this work, we investigate the environmental effect on the creep behavior of Hastelloy X at 9000C in helium and air. Since helium coolant in HTGR is expected to be carburizing and very weakly oxidizing for most metals, testings were focused on the effect of carburizing and slight oxidation. Carburization decreases secondary creep strain rate and delays tertiary creep initiation. On the other hand, the crack growth rate on the specimen surface is enhanced due to very weak oxidation in helium, therefore the tertiary creep strain rate becomes larger than that in air. The rupture time of Hastelloy X was shorter in helium when compared with in air. Stress versus rupture time curves for both environments do not deviate with each other during up to 5000 hours test, and a ratio of rupture stress in helium to that in air was about 0.9

  4. Temperature dependence of creep properties of cold-worked Hastelloy XR

    International Nuclear Information System (INIS)

    The creep properties of Hastelloy XR, in a solution treated, 10% or 20% cold-worked condition, were investigated at temperatures from 800 to 1,000degC for the duration of creep tests up to about 2,500 ks. At 800 and 850degC, the steady-state creep rate and rupture ductility decreased and the rupture life increased after cold work of 10% or 20%. Although the rupture life of the 10% cold-worked alloy was longer at 900degC than that of the solution treated one, the rupture lives of the 10% cold-worked and solution treated alloys were almost equal at 950degC, which is the highest helium temperature in an intermediate heat exchanger of the High Temperature Engineering Test Reactor (HTTR). The beneficial effect of 10% cold work on the rupture life and the steady-state creep rate disappeared at 1,000degC. The beneficial effect of 20% cold work disappeared at 950degC because significant dynamic recrystallization occurred during creep. While rupture ductility of this alloy decreased after cold work of 10% or 20%, it recovered to a considerable extend at 1,000degC. It is emphasized that these cold work effects should be taken into consideration in design, operation and residual life estimation of high temperature components of the HTTR. (author)

  5. TEM characterization of microstructure evolution of 12%Cr heat resistant steels

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, D.; Prat, O.; Sauthoff, G. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany); Garcia, J. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Kaysser-Pyzalla, A.R. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Bochum Univ. (Germany)

    2010-07-01

    A detailed characterization of the microstructure evolution of 12%Cr heat resistant steels at different creep times (100 MPa / 650 C / 8000 h) were carried out by scanning transmission electron microscopy (STEM). The results of the microstructure analysis are correlated with the mechanical properties in order to investigate the influence of different precipitates (especially M{sub 23}C{sub 6}) on the creep strength of the alloys. Precipitation of Laves phase and Z-phase was observed after several hours creep time. Very few Z-phase of the type Cr(V,Ta)N nucleating from existing (V,Ta)(C,N) was observed. Both alloys show growth and coarsening of Laves phase, meanwhile the MX carbonitrides present a very slow growth and coarsening rate. Alloys containing Laves phase, MX and M{sub 23}C{sub 6} precipitates show best creep properties. (orig.)

  6. Design of heat-resistant structure for high temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Material selection, selection of suitable structure and design method for high temperature structure are very important items for the design of heat-resistant structure for HTGRs. Structural metallic materials should be selected by considering manufacturing achievement and application experience, nuclear compatibility and endurance against specified environment. For these purposes, stabilized high temperature alloys, such as Inconel-625, Incolloy-800 and its family alloys, are expected as candidate. These alloys and others are under testing regarding the compatibility with coolant helium, the structural behavior in high temperature helium environment and to radiation dose. Structural design is mainly focused on the following points; in case of the components for high temperature service, heat-resistant and pressure-resistant structures should be separated, suitable heat insulators should be placed effectively, concentric double piping structure may be applicable to meet both requirement cited above, and the concentration of heat-generating core and heat-utilizing equipments should be carried out as far as possible. The design method for high temperature structure is in progress. Material behavior or creep and other performances at high temperature and in helium environment have been investigated, but the data on the materials corresponding to each fracture mechanism should be accumulated, such as the coupled effect of creep and fatigue, creep buckling, and so on. The more reliable design criteria and method will be completed in near future with these research and development works. (Iwase, T.)

  7. ISOLATION OF HEAT RESISTANT FUNGI FROM CANNED FRUITS

    OpenAIRE

    Sani Ibrahim; M. B.Anusha; P. Udhayaraja

    2014-01-01

    -Increase in the consumption of canned fruit juice rather than the fruit itself raises alarmonto the safety of these canned juices as they are stored for longer period of time unlike the fruit and dormant if spores present could germinate and cause spoilage. Heat-resistant molds are characterized by the production of ascospores or similar structures with heat resistance, in some instances comparable to bacterial spores. This enables them to survive even when they are thermally...

  8. Factors Contributing to Heat Resistance of Clostridium perfringens Endospores?

    OpenAIRE

    Orsburn, Benjamin; Melville, Stephen B.; Popham, David L.

    2008-01-01

    The endospores formed by strains of type A Clostridium perfringens that produce the C. perfringens enterotoxin (CPE) are known to be more resistant to heat and cold than strains that do not produce this toxin. The high heat resistance of these spores allows them to survive the cooking process, leading to a large number of food-poisoning cases each year. The relative importance of factors contributing to the establishment of heat resistance in this species is currently unknown. The present stu...

  9. Determination of operational ability of heat resistant materials with regard to concept of kinetic theory of solid body strength

    International Nuclear Information System (INIS)

    An equation for structural long-time strength is proposed for the estimation of heat-resistant material metal durability at different kinds of complex stresses (including uniaxial tension). The physical essence of the effect produced by the kind of a complex stress on the durability is revealed. The equation validity is illustrated using austenite and perlite grade steel and nickel alloy. A possibility of estimating the power equipment element durability is shown. 13 refs., 2 tabs

  10. Oxidation phenomena of nickel-base alloys in high temperature water

    Energy Technology Data Exchange (ETDEWEB)

    Kanazawa, Y.; Tsubota, M. [Toshiba Corp., Yokohama (Japan). Heavy Apparatus Engineering Lab.

    1996-03-01

    Surface oxidation of nickel-base and iron-base super alloys in high temperature low dissolved oxygen water environment was investigated by FE-SEM and X-ray diffraction analysis. Observed oxides on the surface of the alloys were as follows, =Incoloy 800; spinel type oxide (M3O4), Inconel 625; spinel type oxide + nickel oxide + chromium hydroxide, Hastelloy C22; nickel oxide + chromium hydroxide, Hastelloy B2; nickel oxide= Compared to high iron content Incoloy 800, Hastelloy B2 showed large weight loss, and it was assumed that iron is very important element for producing the stable oxide in the low oxygen content high temperature water environment. (author)

  11. Oxidation phenomena of nickel-base alloys in high temperature water

    International Nuclear Information System (INIS)

    Surface oxidation of nickel-base and iron-base super alloys in high temperature low dissolved oxygen water environment was investigated by FE-SEM and X-ray diffraction analysis. Observed oxides on the surface of the alloys were as follows, =Incoloy 800; spinel type oxide (M3O4), Inconel 625; spinel type oxide + nickel oxide + chromium hydroxide, Hastelloy C22; nickel oxide + chromium hydroxide, Hastelloy B2; nickel oxide= Compared to high iron content Incoloy 800, Hastelloy B2 showed large weight loss, and it was assumed that iron is very important element for producing the stable oxide in the low oxygen content high temperature water environment. (author)

  12. Evaluation of Hastelloy X for gas-cooled-reactor applications

    International Nuclear Information System (INIS)

    Hastelloy X is a potential structural material for use in gas-cooled reactor systems. In this application data are necessary on the mechanical properties of base metals and weldments under realistic service conditions. The test environment studied was helium that contained small amounts of H2, CH4, and CO. It is shown that this environment is carburizing with the kinetics of this process, becoming rapid above 8000C. Suitable weldments of Hastelloy X were prepared by several processes; those weldments generally had properties similar to the base metal except for lower fracture strains under some conditions. Some samples were aged up to 20,000 h in the test gas and tested, and some creep tests on as-received material exceeded 40,000 h. The predominant effect of aging was the significant reduction of the fracture strains at ambient temperature; the strains were lower when the samples were aged in HTGR helium than when aged in inert gas. Under some conditions aging also increased the yield and ultimate tensile strength. Limited impact testing showed that the impact energy at 250C was reduced drastically by aging at 871 and 7040C

  13. Weldability of the superalloys Haynes 188 and Hastelloy X by Nd:YAG

    Directory of Open Access Journals (Sweden)

    Graneix Jérémie

    2014-01-01

    Full Text Available The requirements for welded aircraft parts have become increasingly severe, especially in terms of the reproducibility of the geometry and metallurgical grade of the weld bead. Laser welding is a viable method of assembly to meet these new demands, because of automation, to replace the manual TIG welding process. The purpose of this study is to determine the weldability of Hastelloy X and Haynes 188 alloys by the butt welding process with a Nd:YAG laser. To identify the influential parameters of the welding process (laser power, feed rate, focal diameter and flow of gas while streamlining testing, an experimental design was established with the CORICO software using the graphic correlation method. The position of the focal point was fixed at 1/3 of the thickness of the sheet. The gas flow rate and the power of the beam have a major effect on the mechanical properties and geometry of the weld. The strength of the weld is comparable to that of the base metal. However, there is a significant decrease in the elongation at break of approximately 30%. The first observations of the cross section of the weld by scanning electron microscopy coupled with EBSD analysis show a molten zone presenting dendritic large grains compared to the equiaxed grains of the base metals without a heat affected zone.

  14. Humidity affects genetic architecture of heat resistance in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Bubliy, Oleg A; Kristensen, Torsten Nygård

    2012-01-01

    Laboratory experiments on Drosophila have often demonstrated increased heritability for morphological and life-history traits under environmental stress. We used parent-offspring comparisons to examine the impact of humidity levels on the heritability of a physiological trait, resistance to heat, measured as knockdown time at constant temperature. Drosophila melanogaster were reared under standard nonstressful conditions and heat-shocked as adults at extreme high or low humidity. Mean knockdown time was decreased in the stressful dry environment, but there was a significant sex-by-treatment interaction: at low humidity, females were more heat resistant than males, whereas at high humidity, the situation was reversed. Phenotypic variability of knockdown time was also lower in the dry environment. The magnitude of genetic correlation between the sexes at high humidity indicated genetic variation for sexual dimorphism in heat resistance. Heritability estimates based on one-parent-offspring regressions tended to be higher under desiccation stress, and this could be explained by decreased environmental variance of heat resistance at low humidity. There was no indication that the additive genetic variance and evolvability of heat resistance differed between the environments. The pattern of heritability estimates suggests that populations of D. melanogaster may have a greater potential for evolving higher thermal tolerance under arid conditions.

  15. FINITE ELEMENT ANALYSIS OF HASTELLOY C-22HS IN END MILLING

    OpenAIRE

    K.Kadirgama; M.M.Rahman; A.R. Ismail; R.A. Bakar

    2011-01-01

    This paper presents a finite element analysis of the stress distribution in the end milling operation of nickel-based superalloy HASTELLOY C-2000. Commercially available finite element software was used to develop the model and analyze the distribution of stress components in the machined surface of HASTELLOY C-22HS following end milling with coated carbide tools. The friction interaction along the tool-chip interface was modeled using the Coulomb friction law. It was found that the stress ha...

  16. Developmentof plaster compositions that have improved heat resistance ?????????? ??????????? ???????? ?????????? ??????????????

    Directory of Open Access Journals (Sweden)

    Akulova Mariya Vladimirovna

    2013-02-01

    Full Text Available Protection of structures and materials from the adverse effects of the environment is a relevant challenge to be tacked both by the teams of researchers and workers on site. A universal method of protection contemplates the use of cladding and paints. There are classes of finishing materials that have special protective properties.Flame-resistant finishes obstruct the burning of structures, and in some cases they can even prevent inflammation. A universal method of protection is the plastering of the surface of a structure. Plastering is applicable to concrete, masonry, metal as well as timber. Development of heat resistant plaster is relevant due to numerous fires in Russia.This article represents an overview of the research into the influence of composite binders and fillers onto the physical and mechanical properties of the heat resistant plaster.Portland cement M 500 was used as a composite binder. Liquid sodium water glass with the density of 1,300 – 1,500 kg/m3 and the silicate modulus value of 2.4 – 2.8 was also applied. Glass sand with the fineness of 0.315 – 1.25, mineral wool fibers that were4 - 6 mm long (with the density of 50 kg/m3 were applied as fillers.Sugar is known as an excellent inhibitor of Portland cement. Liquid glass binders are very effective if added to heat resistant concretes and mortars. This fact was mentioned in the works of K.D. Nekrasov, A.P. Tarasov, G.P. Gorlov, B.D. Toturbiev and others, and it has been proven in practice. It is noteworthy that liquid glass demonstrates high adhesive strength in terms of all materials. Its adhesive strength is 3...5 times higher than that of the cement, and this fact can serve as the basis for the development of highquality heat-resistant solutions.The resulting composition is an excellent heat resistant plaster; its physical-mechanical and thermal properties are not inferior to heat resistant mortars based on imported additives.??????????? ???????? ?????????? ?????????????? ???????? ?????????? ????????? ?????? ???????????? ??????????? ?? ??????????? ?????????? ??????????. ????????? ???????????? ??????? ???????? ? ????????????, ????????? ????????????? ??????????? ????????????? ? ??????? ???????? ?????????? ???????????? ??? ???? ??????????. ???????? ??????????? ????????, ?????????????? ??????? ? ???? ????, ??? ? ???????? ????????.

  17. Design of martensitic/ferritic heat-resistant steels for application at 650 deg. C with supporting thermodynamic modelling

    International Nuclear Information System (INIS)

    In view of developing novel heat-resisting steels for applications in conventional power plants with service temperatures of 650 deg. C, a series of martensitic/ferritic model steels with 12 wt.%Cr were studied to achieve an increased creep resistance through additional alloying with various elements for controlled precipitation of M23C6 carbides, MX carbonitrides and intermetallic Laves phase. The alloy design relied on thermodynamic simulation calculations using Thermo-Calc and DICTRA. The mechanical testing concentrated on creep at 650 deg. C for up to 8000 h. The alloy optimization resulted in creep rupture strengths above those of the martensitic/ferritic P92 steel. The work was part of a cooperative project within the German MARCKO program

  18. Design of martensitic/ferritic heat-resistant steels for application at 650 deg. C with supporting thermodynamic modelling

    Energy Technology Data Exchange (ETDEWEB)

    Knezevic, V.; Balun, J. [Max-Planck-Institut fuer Eisenforschung GmbH, 40074 Duesseldorf (Germany); Sauthoff, G. [Max-Planck-Institut fuer Eisenforschung GmbH, 40074 Duesseldorf (Germany)], E-mail: g.sauthoff@mpie.de; Inden, G.; Schneider, A. [Max-Planck-Institut fuer Eisenforschung GmbH, 40074 Duesseldorf (Germany)

    2008-03-25

    In view of developing novel heat-resisting steels for applications in conventional power plants with service temperatures of 650 deg. C, a series of martensitic/ferritic model steels with 12 wt.%Cr were studied to achieve an increased creep resistance through additional alloying with various elements for controlled precipitation of M{sub 23}C{sub 6} carbides, MX carbonitrides and intermetallic Laves phase. The alloy design relied on thermodynamic simulation calculations using Thermo-Calc and DICTRA. The mechanical testing concentrated on creep at 650 deg. C for up to 8000 h. The alloy optimization resulted in creep rupture strengths above those of the martensitic/ferritic P92 steel. The work was part of a cooperative project within the German MARCKO program.

  19. 16. lecture meeting of the Association for Heat-Resistant Steels and the Association for High-Temperature Materials, on 'Long-term performance of heat-resistant steels and high-temperature materials'. Thermal stress of materials. Proceedings

    International Nuclear Information System (INIS)

    The proceedings contain 17 contributions on the following subjects (selection): 1) Development of the microstructure of the martensitic tempered steel X22CrMoV12-1 in fatigue tests up to 80000 h. 2) Influences on creep-induced pore formation and their detection in heat-resistant, low-alloyed steels CrMoV. 3) Endurance properties of highly creep-resistant bolt and blade steel X19CrMoVNbN11-1 in fatigue tests up to 600 C. 4) Creep behaviour of a welded 'P91' pressure vessel. 5) State of the development of improved 9 to 10%-CrMoVNb steels for turbines having steam parameters of 600 C. 6) Fracture-mechanical comparison of the mixed compound X20CrMoV12-1 and G17CrMoV5-11 for determining critical defect variables. 7) Creep-to-crack behaviour of powerplant steels. 8) Behaviour of defects in forgings or castings under creep or creep-fatigue stress. 9) Behaviour of heat-resistant steels under multistage fatigue stress. 10) Connection between failure and multiaxial stress in creep loaded pipe elbows. 11) Contribution to the characterization of long-term heat resistance of steels 12CrMo9-10 and their welds. 12) Contribution to the estimation of long-term heat resistance of the higher-resistant unalloyed steel type G20Mn5, well suitable for welding. 13) Creep equations for highly creep resistant materials. (orig./MM)

  20. Development of heat resistant ion exchange resin. First Report

    International Nuclear Information System (INIS)

    In nuclear power stations, as a means of maintaining the soundness of nuclear reactors, the cleaning of reactor cooling water has been carried out. But as for the ion exchange resin which is used as the cleaning agent in the filtrating and desalting facility in reactor water cleaning system, since the heat resistance is low, high temperature reactor water is cooled once and cleaned, therefore large heat loss occurs. If the cleaning can be done at higher temperature, the reduction of heat loss and compact cleaning facilities become possible. In this study, a new ion exchange resin having superior heat resistance has been developed, and the results of the test of evaluating the performance of the developed ion exchange resin are reported. The heat loss in reactor water cleaning system, the heat deterioration of conventional ion exchange resin, and the development of the anion exchange resin of alkyl spacer type are described. The outline of the performance evaluation test, the experimental method, and the results of the heat resistance, ion exchange characteristics and so on of C4 resin are reported. The with standable temperature of the developed anion exchange resin was estimated as 80 - 90degC. The ion exchange performance at 95degC of this resin did not change from that at low temperature in chloride ions and silica, and was equivalent to that of existing anion exchange resin. (K.I.)

  1. Evaluation of long-term creep properties of hastelloy XR in simulated high-temperature gas-cooled reactor helium

    International Nuclear Information System (INIS)

    Creep properties are among the important basic items of material performance for design of high temperature components of high-temperature gas-cooled reactors (HTGRs). In order to evaluate creep properties of Hastelloy XR (a modified version of the conventional Hastelloy X) developed for the High-Temperature Engineering Test Reactor (HTTR), long-term creep tests were carried out in simulated HTGR helium at 800, 900 and 1000degC. The test results up to about 50,000h showed no significant degradation in creep properties. The creep-rupture strength obtained through the long-term tests was above the level corresponding to the design allowable creep-rupture stress of the HTTR. Rupture lives could be estimated with sufficient accuracy using Larson-Miller parameter. The values of the stress exponent were 4.5 to 5.7 when the stress dependence of the steady-state creep rate was expressed in terms of the Norton equation. It was judged that dominant creep process was dislocation creep. The relationship between the steady-state creep rate and the rupture life was expressed in terms of the Monkman-Grant equation. Carburization during creep in simulated HTGR helium did not degrade creep properties of this alloy. Internally formed cavities and cracks were initiated at sites of precipitates at grain boundaries, growing nearly perpendicular to the stress axis. Creep fracture was caused by the nucleation, growth and link-up of grain boundary cavities in long-term tests. Two phases, Cr-rich carbide and Mo-rich carbide, co-existed in specimens after long-term creep tests. (author)

  2. Study on internal pressure creep strength of Hastelloy X cylindrical specimen containing an axial surface notch

    International Nuclear Information System (INIS)

    Creep tests of Hastelloy X alloy have been performed at 900 deg C under internal pressure, using cylindrical specimens with an artificial defect. The purpose of this research is to investigate the effect of defect size on the creep strength. Two kinds of cylindrical specimens were used. One was 62 mm in outer diameter, 3.0 mm in thickness and 240 mm in length. Another was 66 mm in outer diameter, 6.0 mm in thickness and 240 mm in length. Axial notches were machined on the outer surface of these specimens by a milling cutting. Diametral deformation of the specimen was measured during the test by dial gauges mounted on quartz rods. Creep crack growth depth was measured using the electrical potential method. The numerical analysis using a finite element program ADINA has been performed to investigate the creep deformation around the artificial defect. Analytical model represents one-half of the cylindrical specimen which is 56.0 mm in inner diameter and 3.0 mm in thickness, and has the axial notch of 1.0 mm in depth with infinite length. Elastic-plastic and creep analysis of this model was carried out by incremental method of the time step of 0.01 hours. The following results are concluded from these tests and analyses. [1] The creep rupture time decreases with increasing notch length. [2] The electric potential method is very useful for measuring the creep crack growth depth. [3] The initial creep deformation around the notch is obtained from the finite element analysis. (author)

  3. Corrosion resistance of ?-solid solution and hardening ?'-phase of nickel alloys in sodium sulfate and chloride melts

    International Nuclear Information System (INIS)

    Corrosion testings of model alloys, corresponding by chemical composition to simple and complex-alloyed ?- and ?'-phases of nickel heat-resistant alloys are conducted in sodium sulfate and chloride melts. It is ascertained that heat resistant nickel alloys containing over 50 % of hardening ?'-phase, are subject to disastrous sulfide corrosion (SC). Resistance against SC alloys containing below 50 % of ?'-phase is determined by the resistance of ?-solid solution. 10 refs., 3 figs., 2 tabs

  4. Heat-resistant bacterial phytase in broiler pelleted diets

    Scientific Electronic Library Online (English)

    TC de F, Carlos; LCGS, Barbosa; NN, Shiroma; RL, Dari; G, Baolin; W, Yongcheng; CS da S, Araújo; LF, Araújo.

    2015-03-01

    Full Text Available The objective of the study was to evaluate the effects of a heat-resistant bacterial phytase added to pelleted diets on mineral digestibility, live performance, carcass traits, and bone quality of broilers. Three treatments were evaluated: Positive control; negative control, with 0.10 points reducti [...] on in calcium level and 0.15 points reduction in available phosphorus level; and negative control + phytase at 500 FTU/kg. Mineral digestibility and bone quality results demonstrated that the evaluated phytase resisted pelleting as it increased the utilization of the minerals present in the diet.

  5. 9-12Cr heat-resistant steels

    CERN Document Server

    Yan, Wei; Shan, Yiyin; Yang, Ke; Sha, Wei

    2015-01-01

    With China becoming a major force in steel research and development, this book highlights the work of a group from the Chinese Academy of Sciences, led by the first four authors. This group has the ideal knowledge base for writing this updated book on heat-resistant steels. The fifth author, Sha, based in the UK, has been collaborating with the Chinese group since 2009 and is the lead or sole author of four research books, all published in English. The last book, "Steels: from materials science to structural engineering," was published by Springer in 2013. Within two months of its publication

  6. Creep properties of hastelloy x and their application to the structural design

    International Nuclear Information System (INIS)

    In the creep curve of Hastelloy X, it was difficult to divide it into the three stages of creep. However, these stages were made distinguishable by plotting the relationship between creep rates and time in double-logarithmic coordinates. All the creep data of Hastelloy X, except the isochronous stress-strain curves, required for determining the design stress intensities S sub(o) and S sub(t) were arranged through the Larson-Miller parameter. The isochronous stress-strain curves for a heat of Hastelloy X were derived from the constitutive equations obtained from short-term data. A fairly good agreement between the predicted data and the experimental data was obtained. (auth.)

  7. Electron emission from nickel-alloy surfaces in cesium vapor

    Science.gov (United States)

    Manda, M.; Jacobson, D.

    1978-01-01

    The cesiated electron emission was measured for three candidate electrodes for use as collectors in thermionic converters. Nickel, Inconel 600 and Hastelloy were tested with a 412 K cesium reservoir. Peak emission from the alloys was found to be comparable to that from pure nickel. Both the Inconel and the Hastelloy samples had work functions of 1.64 eV at peak emission. The minimum work functions were estimated to be 1.37 eV at a probe temperature of 750 K for Inconel and 1.40 eV for Hastelloy at 665 K. The bare work function for both alloys is estimated to be approximately the same as for pure nickel, 4.8 eV.

  8. Inactivation of heat-resistant pectinmethylesterase from orange by manothermosonication.

    Science.gov (United States)

    Vercet, A; Lopez, P; Burgos, J

    1999-02-01

    Pectinmethylesterase of navel oranges shows two fractions greatly differing in thermostability. The most thermostable fraction accounts for approximately 10% of total activity. The thermal inactivation of this fraction follows first-order kinetics both in 5 mM, pH 3.5, citrate buffer and in orange juice at the same pH, showing a z value of 5.1 degrees C and an activation energy (E(a)) of 435 kJ mol(-)(1) K(-)(1). The heat resistance of the enzyme is approximately 25-fold higher in the juice than in citrate buffer. When ascorbic acid, sucrose, glucose, and fructose are added to the citrate buffer at the concentrations found in orange juice, the heat resistance of the enzyme increases 3-fold. The addition of pectin at 0.01% concentration multiplies it by a factor of 50. Manothermosonication (MTS), the simultaneous application of heat and ultrasound under moderate pressure (200 kPa), at 72 degrees C, increases the inactivation rate 25 times in buffer and >400 times in orange juice. MTS inactivation shows a higher z value (35.7 degrees C) and lower E(a) (56.9 kJ mol(-)(1) K(-)(1)) than simple heating. PMID:10563912

  9. Study of Rigid Cross-Linked PVC Foams with Heat Resistance

    Directory of Open Access Journals (Sweden)

    Chenhui Zhao

    2012-12-01

    Full Text Available Three heat resistant cross-linked PVC foam plastics were prepared and their performances were compared with universal cross-linked PVC structural foam. The results show that these three heat resistant foams have higher glass transition temperatures (close to 100 °C than universal structural foam (83.2 °C. Compared with the universal structural foam, the three heat resistant foams show much higher decomposition temperature and better chemical stability due to the crosslinking of PVC macromolecular chains. The heat distortion temperature (HDT values of the three heat resistant foam plastics are just a little higher than that of universal structural foam. The three heat resistant foam plastics have good dimensional stability at 140 °C, and when used as core material can closely adhere to the face plates in medium temperature curing processes. Compared with universal structural foam, the three heat resistant foam plastics have slightly better mechanical properties.

  10. Heat-resistant mechanism of transgenic rape by 45Ca isotope tracer

    International Nuclear Information System (INIS)

    The Ca2+ uptake differences of the rape with heat-resistant gene and the general rape were investigated by 45Ca isotope tracer. The results showed that the rape with heat-resistant gene can strengthen the regulation of calcium absorption. The calcium regulation ability of the heat-resistant genes may be able to play in the rape aspect of the mechanism of resistance. (authors)

  11. Reduction in mechanical anisotropy through high temperature heat treatment of Hastelloy X processed by Selective Laser Melting (SLM)

    Science.gov (United States)

    Etter, T.; Kunze, K.; Geiger, F.; Meidani, H.

    2015-04-01

    Selective Laser Melting (SLM) is an additive manufacturing technology used to directly produce metallic parts from thin powder layers. To evaluate the anisotropic mechanical properties, tensile test specimens of the Ni-base alloy Hastelloy X were built with the loading direction oriented either parallel (z-specimens) or perpendicular to the build-up direction (xy- specimens). Specimens were investigated in the “as-built” condition and after high temperature heat treatment. Tensile tests at room temperature and at 850°C of “as-built” material have shown different mechanical properties for z- and xy-specimens. The anisotropy is reflected in the Young's modulus, with lower values measured parallel to the build-up direction. It is shown that the anisotropy is significantly reduced by a subsequent recrystallization heat treatment. The characterization of microstructural and textural anisotropy was done by Electron Back Scatter Diffraction (EBSD) analysis. Predictions of Young's modulus calculated from the measured textures compare well with the data from tensile tests.

  12. Analyzing the effect of cutting parameters on surface roughness and tool wear when machining nickel based hastelloy - 276

    International Nuclear Information System (INIS)

    Machining parameters has an important factor on tool wear and surface finish, for that the manufacturers need to obtain optimal operating parameters with a minimum set of experiments as well as minimizing the simulations in order to reduce machining set up costs. The cutting speed is one of the most important cutting parameter to evaluate, it clearly most influences on one hand, tool life, tool stability, and cutting process quality, and on the other hand controls production flow. Due to more demanding manufacturing systems, the requirements for reliable technological information have increased. For a reliable analysis in cutting, the cutting zone (tip insert-workpiece-chip system) as the mechanics of cutting in this area are very complicated, the chip is formed in the shear plane (entrance the shear zone) and is shape in the sliding plane. The temperature contributed in the primary shear, chamfer and sticking, sliding zones are expressed as a function of unknown shear angle on the rake face and temperature modified flow stress in each zone. The experiments were carried out on a CNC lathe and surface finish and tool tip wear are measured in process. Machining experiments are conducted. Reasonable agreement is observed under turning with high depth of cut. Results of this research help to guide the design of new cutting tool materials and the studies on evaluation of machining parameters to further advance the productivity of nickel based alloy Hastelloy - 276 machining.

  13. 15. lecture meeting of the Association for heat-resistant steels and the Association for high-temperature materials, on ''Long-term performance of heat-resistant steels and high-temperature materials''. Thermal stress of materials

    International Nuclear Information System (INIS)

    The proceedings contain 15 contributions with the following titles: 1. Documentation of fatigue data and preparation for the evaluation with the ZSF program system; 2. Evaluation of strain limit-spread bands with the DESA program; 3. Evaluation of fatigue data with the MCM program; 4. Calculated evaluation of fatigue tests with the example of steel 13 CrMo 4 4; 5. How to improve the creep properties of modified chromium steels; 6. Development work at Nb-stabilized martensitic 9 to 12% chromium steels for applications in energy technology; 7. Microstructure and deformation of the steel X 20 CrMoV 12 1 at high temperature; 8. Influence of multiaxial stress on the long-term creep processes in steels; 9. Determination of the lifetime of an austenitic big-sized plate under creep-fatigue stress - comparative evaluations of design calculation and experiment; 10. Experimental and calculated examination of the fatigue performance of notched specimens; 11. Structure-property relations at heat resistant pipe steel 15 CrMoV 5 10; 12. Results of the quantitative structural analysis of long-term stressed 15 CrMoV 5 10 and 14 MoV 6 3; 13. Behaviour of protective coatings on high temeprature materials under cyclical stress; 14. Mechanical endurance of nickel-base alloys in the high temperature range; 15. Influence of scaling on the fatigue performance of heat resistant steels. (orig./MM)

  14. Polymeric Coatings Containing Antioxidants to Improve UV- and Heat Resistance of Chrome-Free Leather

    Science.gov (United States)

    For automotive upholstery leather, UV and heat resistance are very important qualities, particularly for non-chrome-tanned (chrome-free) leather. One of our research endeavors has focused on an environmentally friendly finishing process that will improve the UV and heat resistance of automobile uph...

  15. Structure and properties of cast alloys of a molybden-titanium carbide system

    International Nuclear Information System (INIS)

    Studies have been carried out on the structure, phase composition and mechanical properties over a wide temperature range of cast alloys of the molybden-titanium carbide system, and it has been noted that the heat-resistance level is determined by the nature of excess phases. A possibility is shown for a directed heat-resistance control of molybdenum at the cost of changes in the content and ratio of alloying elements and thermal treatment of alloys

  16. Viability and heat resistance of murine norovirus on bread.

    Science.gov (United States)

    Takahashi, Michiko; Takahashi, Hajime; Kuda, Takashi; Kimura, Bon

    2016-01-01

    Contaminated bread was the cause of a large-scale outbreak of norovirus disease in Japan in 2014. Contamination of seafood and uncooked food products by norovirus has been reported several times in the past; however the outbreak resulting from the contamination of bread products was unusual. A few reports on the presence of norovirus on bread products are available; however there have been no studies on the viability and heat resistance of norovirus on breads, which were investigated in this study. ce:italic>/ce:italic> strain 1 (MNV-1), a surrogate for human norovirus, was inoculated directly on 3 types of bread, but the infectivity of MNV-1 on bread samples was almost unchanged after 5days at 20°C. MNV-1 was inoculated on white bread that was subsequently heated in a toaster for a maximum of 2min. The results showed that MNV-1 remained viable if the heating period was insufficient to inactivate. In addition, bread dough contaminated with MNV-1 was baked in the oven. Our results indicated that MNV-1 may remain viable on breads if the heating duration or temperature is insufficient. PMID:26485672

  17. Behaviour of heat-resistant steels under multistage fatigue stress

    International Nuclear Information System (INIS)

    Four heat-resistant steels (10 CrMo 9 10, 28 CrMoNiV 4 9, X 22 CrMoV 12 1, X 6 CrNiMo 17 13), were used to examine the fatigue under multistage rectangular cyclic stress. The load cycles were made to be similar to the stress affecting power plant components. These are mainly cycles with decreasing and/or increasing stresses, with the temperature or both variables at the same time having been varied in some cases. As characteristical parameters of the modified life-fraction rule, the relative fracture life and for characterizing strains the relative strain life as well were determined. For the assessment of the relative life under any multistage stress, a new step hypothesis, applicable to all possible elementary stress steps, was developed. This hypothesis is able to predict even a consequential effect by means of additional rules. In comparison to this hypothesis, the simple life fraction rule which is unapt for single-stage stress, results in a somehow better prognosis of the fraction time and strain endurance limits under multistage stress. (orig./MM)

  18. Preselection of Ni-Cr(-Mo) alloys as potential canister materials for vitrified high active nuclear waste by electrochemical testing

    Science.gov (United States)

    Bort, H.; Wolf, I.; Leistikow, S.

    1987-07-01

    Several Ni-Cr(-Mo) alloys (Hastelloy C4, Inconel 625, Sanicro 28, Incoloy 825, Inconel 690) were tested by electrochemical methods to characterize their corrosion behavior in chloride containing solutions at various temperatures and pH-values in respect to their application as canister materials for final radioactive waste storage. Especially, Hastelloy C4 was tested by potentiodynamic, potentiostatic and galvanostic measurements. As electrolytes H 2SO 4 solutions were used, as parameters temperature, chloride content and pH-value were varied. All tested alloys showed a clearly limited resistance against pitting corrosion phenomena; under severe conditions even crevice corrosion phenomena were observed. The best corrosion behavior, however, is shown by Hastelloy C4, which has the lowest passivation current density of all tested alloys and the largest potential region with protection against local corrosion phenomena.

  19. Achievements and development outlook of refractory metal base alloys

    International Nuclear Information System (INIS)

    A review of papers on heat resistance of refractory alloys and methods of its improvement is presented. Heat resistance in the temperature range of 0.3-0.6 Tm may be achieved by strain hardening. Heat resistance at temperatures above 0.6 Tm can be achieved only by alloying the solid solution with more refractory metals, as well as elements forming a second finely-dispersed phase. Thus, alloying of molybdenum with 0.1-0.2% Zr increases the recrystallization temperature almost by 300 deg C and improves the heat resistance at 1200 deg C twofold. Zirconium is added to all niobium alloys: it strengthens the solid solution and forms a carbide and a nitride phases in the presence of carbon and nitrogen. Problems of low-temperature brittleness of refractory metals are discussed. A tendency of molybdenum alloys to hot brittleness at 1400-1800 deg C and its decrease resulting from alloying with zirconium and hafnium has been noted. High corrosion resistance of pyrofusible metals and their alloys is stressed. Heat-resistance data for niobium-, molybdenum-and tungsten-based alloys and dependence of mechanical properties on temperature and strain are presented

  20. Interfacial Reactions of Ion Beam Mixed SiC film deposited onto Hastelloy X substrate

    International Nuclear Information System (INIS)

    As we reported previously, the materials used for the SO3 decomposer in Iodine-Sulfur cycle for Nuclear Hydrogen Production System require excellent mechanical properties as well as a high corrosion resistance in SO2/SO3 environment at an elevated temperature up to 950 .deg. C. So far, no metallic materials have been proved to be useful in such an environment. We have studied a surface modification of Hastelloy X by a SiC coating and an ion beam mixing. It is expected that only deposited SiC film is easily peeled off during heating at the elevated temperature. However, the SiC coating on Hastelloy X followed by ion beam mixing (IBM) is sustained at the elevated temperature above 900 .deg. C. The mechanisms of the good adhesion at the interface was studies using X-TEM, AES, XPS, XRD, X-SEM and EDS are presented

  1. Heat-resistant variants of Chinese hamster fibroblasts altered in expression of heat shock protein.

    OpenAIRE

    Laszlo, A.; Li, G.C.

    1985-01-01

    Heat-resistant variants of the Chinese hamster HA-1 line have been isolated after repeated heat treatments. The heat-resistant phenotype has been stable for over 70 passages. One of the members of the 70-kDa heat shock protein family was found to be synthesized at greater levels in the heat-resistant variants under normal growth conditions. Mild heat treatment of the variant lines induced a transient thermotolerance that was accompanied by additional increase in the synthesis of the 70-kDa he...

  2. Hastelloy-X for high-temperature gas-cooled reactor applications

    International Nuclear Information System (INIS)

    Hastelloy-X is a potential structural material for use in gas-cooled reactor systems. In this application, data are necessary on the mechanical properties of base metal and weldments under realistic service conditions. The test environment studied was helium that contained small amounts of H2, CH4, and CO. This environment was found to be carburizing, with the kinetics of this process becoming rapid above 8000C. Suitable weldments of Hastelloy-X were prepared by several processes; those weldments generally had the same properties as base metal except for lower fracture strains under some conditions. Some samples were aged for up to 20 000 h in the test gas and tested, and some creep tests on as-received material exceeded 40 000 h. The predominant effects of aging were the significant reduction in the fracture strains at ambient temperature and the lower strains for samples aged in high-temperature gas-cooled reactor (HTGR) helium than for those aged in inert gas. Under some conditions, aging also resulted in increased yield and ultimate tensile strength. Creep tests failed to show the effects of environment, aging, or welding on the creep strength of Hastelloy-X; however, the fracture strains for weldments were generally lower than they were for base metal. Prior aging in inert gas for 20 000 h at 538 and 8710C reduced the fatigue life slightly, but no difference was observed in the fatigue properties of samples aged in air and HTGR helium environments

  3. High quality Hastelloy films deposited by XeCl pulsed laser ablation

    International Nuclear Information System (INIS)

    Pulsed laser ablation has been used to deposit Hastelloy thin films on carbon steel substrates at room temperature. Depositions have been carried out by XeCl excimer laser ablation (?=308 nm, ?=30 ns) of a bulk Hastelloy target in a high vacuum system (p=10-5 Pa). In order to obtain as thick and uniform films as possible, we took in account the maximum plume deflection angle we observed in our experiments. Optical studies of the plume revealed a deviation of about 15 deg. towards the laser beam. To minimize the effects of the plume deflection, the substrate was placed along the deflected plume axis instead of the normal to the target surface. The plume deflection angle and the ablation rate of Hastelloy target as a function of number of laser pulses per site have been also measured. Scanning electron microscopy (SEM), energy dispersion X-ray (EDX) spectroscopy and X-ray diffraction (XRD) have been performed to analyse, respectively, the surface morphology, the chemical composition and the crystallographic structure of the deposited films. In order to correlate the microstructure of the film surface with its corrosion properties, potentiodynamic curves and linear polarisation resistance analyses have been carried out

  4. Structural peculiarities of tantalum-containing nickel base alloys

    International Nuclear Information System (INIS)

    A comparative analysis was made to elucidate the structure and properties of cast Ni-Cr-Al-Ti and Ni-Cr-Al-Ta heat-resisting alloys which were obtained by directed crystallization. It is shown that alloying with tantalum which strengthens both a solid solution and intermetallic ?'-phase, increases considerably heat resistance of nickel alloys in the 1000-1100 deg C temperature range. Further increase in the strength of Ta containing alloys is achieved due to the formation of primary laminated tantalum monocarbides and isolated secondary tantalum carbides more strongly bonded with the matrix, as compared to the carbides of Cr23C6 type

  5. Influencia de los parámetros de soldeo fuerte en la microestructura y propiedades mecánicas de la unión de la aleación base níquel Hastelloy B2

    Directory of Open Access Journals (Sweden)

    Sotelo, José Carlos

    2014-09-01

    Full Text Available A study of the high vacuum brazing process of solid solution strengthened Hastelloy B2 nickel alloy has been done. A first stage of research has focused on the selection of the most appropriate brazing filler metal to the base material and vacuum furnace brazing process. The influence of welding parameters on joint microstructure constituents, relating the microstructure of the joint to its mechanical properties, has been evaluated. Two gaps of 50 and 200 micrometers, and two dwell times at brazing temperature of 10 and 90 minutes were studied. The braze joint mainly consists of the nickel rich matrix, nickel silicide and ternary compounds. Finally, the results of this study have shown the high bond strength for small gaps and increased dwell times of 90 minutes.Se realizó un estudio pormenorizado del proceso de soldeo fuerte en horno de alto vacío de la aleación base níquel Hastelloy B2 fortalecida por solución sólida. En una primera fase del trabajo se seleccionó el material de aporte acorde al material objeto de unión y a la fuente de calentamiento seleccionada. Posteriormente, se evaluó la influencia del gap (50 y 200 micrómetros y tiempo de permanencia a temperatura de soldeo (10 y 90 minutos sobre los microconstituyentes de la unión, relacionando la microestructura con las propiedades mecánicas de la junta. Los análisis metalográficos mostraron una unión constituida por una matriz rica en níquel, siliciuros de níquel y compuestos ternarios. Finalmente, los resultados de los ensayos mecánicos a esfuerzos cortantes mostraron una elevada resistencia para gaps de 50 micrómetros y tiempos de permanencia de 90 minutos.

  6. Investigation on corrosion behavior of Ni-based alloys in molten fluoride salt using synchrotron radiation techniques

    International Nuclear Information System (INIS)

    Ni-based alloys have been selected as the structural materials in molten-salt reactors due to their high corrosion resistance and excellent mechanical properties. In this paper, the corrosion behavior of some Ni-based superalloys including Inconel 600, Hastelloy X and Hastelloy C-276 were investigated in molten fluoride salts at 750 °C. Morphology and microstructure of corroded samples were analyzed using scanning electron microscope (SEM), synchrotron radiation X-ray microbeam fluorescence (?-XRF) and synchrotron radiation X-ray diffraction (SR-XRD) techniques. Results from ?-XRF and SR-XRD show that the main depleted alloying element of Ni-based alloys in molten fluoride salt is Cr. In addition, the results indicate that Mo can enhance the corrosion resistance in molten FLiNaK salts. Among the above three Ni-based alloys, Hastelloy C-276 exhibits the best corrosion resistance in molten fluoride salts 750 °C. Higher-content Mo and lower-content Cr in Hastelloy C-276 alloy were responsible for the better anti-corrosive performance, compared to the other two alloys

  7. Properties of super alloys for high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    The existing data on the properties at high temperature in helium gas of iron base super alloys. Incoloy-800, -802 and -807, nickel base super alloys, Hastelloy-X, Inconel-600, -617 and -625, and a casting alloy HK-40 were collectively evaluated from the viewpoint of the selection of material for HTGRs. These properties include corrosion resistance, strength and toughness, weldability, tube making, formability, radioactivation, etc. Creep strength was specially studied, taking into consideration the data on the creep characteristics in the actual helium gas atmosphere. The necessity of further long run creep data is suggested. Hastelloy-X has completely stable corrosion resistance at high temperature in helium gas. Incoloy 800 and 807 and Inconel 617 are not preferable in view of corrosion resistance. The creep strength of Inconel 617 extraporated to 1,000 deg C for 100,000 hours in air was the greatest rupture strength of 0.6 kg/mm2 in all above alloys. However, its strength in helium gas began to fall during a relatively short time, so that its creep strength must be re-evaluated in the use for long time. The radioactivation and separation of oxide film in primary construction materials came into question, Inconel 617 and Incoloy 807 showed high induced radioactivity intensity. Generally speaking, in case of nickel base alloys such as Hastelloy-X, oxide film is difficult to break away. (Iwakiri, K.)

  8. Evaluation of candidate alloys for the construction of metal flex hoses in the STS launch environment

    Science.gov (United States)

    Ontiveros, Cordelia

    1988-01-01

    Various vacuum jacketed cryogenic supply lines at the Shuttle launch site use convoluted flexible expansion joints. The atmosphere at the launch site has a very high salt content, and during a launch, fuel combustion products include hydrochloric acid. This extremely corrosive environment has caused pitting corrosion failure in the flex hoses, which were made of 304L stainless steel. A search was done to find a more corrosion resistant replacement material. This study focused on 19 metal alloys. Tests which were performed include electrochemical corrosion testing, accelerated corrosion testing in a salt fog chamber, long term exposure at the beach corrosion testing site, and pitting corrosion tests in ferric chloride solution. Based on the results of these tests, the most corrosion resistant alloys were found to be (in order) Hastelloy C-22, Inconel 625, Hastelloy C-276, Hastelloy C-4, and Inco Alloy G-3. Of these top five alloys, the Hastelloy C-22 stands out as being the best of those tested for this application.

  9. Ductility loss of neutron-irradiated hastelloy-X at elevated temperatures

    International Nuclear Information System (INIS)

    Ductility loss of neutron-irradiated Hastelloy-X at elevated temperatures was examined by post-irradiation slow tensile test. The results were analyzed as functions of test temperature, strain rate, thermal neutron fluence and the associated helium generation due to nuclear transmutation. In addition to the 10B(n, ?)7Li reaction, the contribution of helium generation due to the two-step reaction 58Ni(n, ?)59Ni(n, ?)56Fe at higher fluences was considered. Irradiations were made mostly at 600C, followed by high-temperature tensile tests; the effects of irradiation temperature were examined separately. The post-irradiation ductility generally decreased with temperature increase up to 10000C. Extrapolations of the results of irradiation at 600C gave the apparent fracture ductility values of 3.5% at 9000C and 1.5% at 10000C. Threshold thermal neutron fluences for the ductility loss were also predicted as 6 x 1016n/cm2 at 9000C and 10000C, respectively. Ductility loss was increased when the irradiation was made at temperatures equivalent to the tensile test conditions. The results are discussed in connection with the application of Hastelloy-X for control rod sheath material in high temperature gas-cooled reactor. (author)

  10. Ion Beam Bombarded SiC Coating on Hastelloy X for Nuclear Hydrogen Production System

    International Nuclear Information System (INIS)

    The process heat exchanger (PHE) in the IS cycle of the nuclear hydrogen production system is composed of He gas channels and decomposed sulfuric acid (SO2/SO3/H2O) gas channels. The materials for the PHE require excellent mechanical properties at an elevated temperature as well as a high corrosion resistance in SO2/SO3 environment. In this work, a surface modification of Hastelloy X using a SiC has been studied. The SiC coating is known to improve the lifetime or the performance of metallic substrates when exposed to an aggressive environment. The SiC coated layer exhibits a poor adhesion with Hastelloy X due to a big difference in their coefficients of thermal expansion. we have developed an ion beam mixing (IBM) technique to produce a highly adherent coated layer and to reinforce the base materials and an ion beam hammering(IBH) onto the final SiC coating layer to surmount the vacuum sublimation

  11. Characterization of Hot Deformation Behavior of Hastelloy C-276 Using Constitutive Equation and Processing Map

    Science.gov (United States)

    Zhang, Chi; Zhang, Liwen; Shen, Wenfei; Li, Mengfei; Gu, Sendong

    2015-01-01

    In order to clarify the microstructural evolution and workability of Hastelloy C-276 during hot forming to get excellent mechanical properties, the hot deformation behavior of this superalloy is characterized. The cylindrical specimens were isothermal compressed in the temperature range of 1000-1200 °C and strain rate range of 0.001-5 s-1 on a Gleeble 1500 thermal-mechanical simulator. The flow curves and microstructural investigation indicates that dynamic recrystallization is the prime softening mechanism at the evaluated deformation conditions. The constitutive equation was presented as a function of the deformation temperature, strain rate, and strain, and the deformation activation energy was about 450 kJ/mol. The processing maps based on dynamic materials model at the strains of 0.2, 0.4, 0.6, 0.8, and 1.0 were established, and the processing map at 1.0 strain shows good correspondence to the microstructural observation. The domains in processing map in which the efficiency of power dissipation (?) is higher than 0.25 are corresponding to sufficient dynamic recyrstallization phenomenon, which are suggested to be the optimum working areas for Hastelloy C-276.

  12. Implementation of heat resistant fiber bragg grating sensors for seismic safety in nuclear power plant facilities

    International Nuclear Information System (INIS)

    A Fiber Bragg Grating (FBG) sensor with heat resistance was produced via a point microfabrication technique using a femtosecond pulse laser. FBG is the periodic refractive-index structure in an optical fiber core, where the light of a specific wavelength is reflected. It can be used as temperature or a distorted sensor by measuring change of the reflective wavelength of FBG. We processed FBG using a Chirped Pulse Amplification Erbium-doped Fiber laser. Heating test under operational temperature of Fast Breeder Reactors is now planed. The heat-resistant FBG sensor developed using ultra-short pulse laser processing will contribute to the surveillance of power plants for seismic safety. (author)

  13. Cast, heat-resistant austenitic stainless steels having reduced alloying element content

    Science.gov (United States)

    Muralidharan, Govindarajan [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN; Pankiw, Roman I [Greensburg, PA

    2011-08-23

    A cast, austenitic steel composed essentially of, expressed in weight percent of the total composition, about 0.4 to about 0.7 C, about 20 to about 30 Cr, about 20 to about 30 Ni, about 0.5 to about 1 Mn, about 0.6 to about 2 Si, about 0.05 to about 1 Nb, about 0.05 to about 1 W, about 0.05 to about 1.0 Mo, balance Fe, the steel being essentially free of Ti and Co, the steel characterized by at least one microstructural component selected from the group consisting of MC, M.sub.23C.sub.6, and M(C, N).

  14. Oxidability of certain cast and sintered alloys on the base of TiAl, NiAl and Ni3Al intermetallides

    International Nuclear Information System (INIS)

    TiAl, NiAl, Ni3Al produced by the methods of power metallurgy and casting are studied for heat-resistance and strength. It is stated that the heat-resistance and strength of TiAl produced by the powder metallurgy method is lower than those of the cast one. The heat-resistance of the powdered Ni3Al is similar to the heat-resistance of the cast one at 1000 deg C, but its strength is higher. Yttrium microalloying of TiAl as well as molybdenum alloying of Ni3Al appreciably decreases the oxidation rate of intermetallides mentioned above

  15. Frictional and heat resistance characteristics of coconut husk particle filled automotive brake pad

    Science.gov (United States)

    Bahari, Shahril Anuar; Chik, Mohd Syahrizul; Kassim, Masitah Abu; Som Said, Che Mohamad; Misnon, Mohd Iqbal; Mohamed, Zulkifli; Othman, Eliasidi Abu

    2012-06-01

    The objective of this study was to determine the friction and heat resistance characteristics of automotive brake pad composed with different sizes and percentages of coconut husk particle. The materials used were phenolic resin (phenol formaldehyde) as binder, copper, graphite and brass as friction producer/modifiers, magnesium oxide as abrasive material, steel and barium sulfate as reinforcement while coconut husk particle as filler. To obtain particle, the coconut husk was ground and dried to 3% moisture content. Then the coconut husk particle was screened using 80 mesh (to obtain coarse dust) and 100 mesh (to obtain fine dust). Different percentages of particle, such as 10 and 30% were used in the mixture of brake pad materials. Then the mixture was hot-pressed to produce brake pad. Chase machine was used to determine the friction coefficient in friction resistance testing, while thermogravimetric analyzer (TGA) machine was used to determine the heat decomposition values in heat resistance testing. Results showed that brake pad with 100 mesh and 10% composition of coconut husk particle showed the highest friction coefficient. For heat resistance, brake pad with 100 mesh and 30% composition of coconut husk dust showed the highest decomposition temperature, due to the high percentage of coconut husk particle in the composition, thus increased the thermal stability. As a comparison, brake pad composed with coconut husk particle showed better heat resistance results than commercial brake pad.

  16. Heat resistance of Alicyclobacillus acidocaldarius in water, various buffers, and orange juice.

    Science.gov (United States)

    Palop, A; Alvarez, I; Raso, J; Condón, S

    2000-10-01

    The effect of the pH or the composition of the heating medium and of the sporulation temperature on the heat resistance of spores of a thermoacidophilic spore-forming microorganism isolated from a dairy beverage containing orange fruit concentrate was investigated. The species was identified as Alicyclobacillus acidocaldarius. The spores showed the same heat resistance in citrate-phosphate buffers of pH 4 and 7, in distilled water, and in orange juice at any of the temperatures tested (D120 degrees C = 0.1 min and z = 7 degrees C). A raise in 20 degrees C in the sporulation temperature (from 45 to 65 degrees C) increased the heat resistance eightfold (from D110 degrees C = 0.48 min when sporulated at 45 degrees C to 3.9 min when sporulated at 65 degrees C). The z-values remained constant for all sporulation temperatures. The spores of this strain of A. acidocaldarius were very heat resistant and could easily survive any heat treatment currently applied to pasteurize fruit juices. PMID:11041137

  17. Investigations into forming process of subsurface layers of the titanium VT-9 alloy after electropark alloying

    International Nuclear Information System (INIS)

    Investigation result of the phase composition and structure of the surface layer of the VT-9 titanium alloy after electrospark alloying with Ni, Al, NiAl are presented. It is shown that the surface layer is formed at the expense of the anode material deposition, its interaction with the cathode material and interelectrode medium. At that, the thickness of the layer detected roentgenographically exceeds the thickness of the layer detected metallographically. The obtained data of phase composition as to the depth of the alloyed layer permit to approach selectively to the material of the alloying electrode to increase heat resistance of the VT-9 titanium alloy

  18. A possibility of enhancing Jc in MgB2 film grown on metallic hastelloy tape with the use of SiC buffer layer

    International Nuclear Information System (INIS)

    We have grown MgB2 on SiC buffer layer by using metallic Hastelloy tape as the substrate. Hastelloy tape was chosen for its potential practical applications, mainly in the power cable industry. SiC buffer layers were deposited on Hastelloy tapes at 400, 500, and 600 degrees C by using a pulsed laser deposition method, and then by using a hybrid physical-chemical vapor deposition technique, MgB2 films were grown on the three different SiC buffer layers. An enhancement of critical current density values were noticed in the MgB2 films on SiC/Hastelloy deposited at 500 and 600 degrees C. From the surface analysis, smaller and denser grains of MgB2 tapes are likely to cause this enhancement. This result infers that the addition of SiC buffer layers may contribute to the improvement of superconducting properties of MgB2 tapes.

  19. Heat resistance of bacterial spores correlated with protoplast dehydration, mineralization, and thermal adaptation.

    OpenAIRE

    Beaman, T C; Gerhardt, P.

    1986-01-01

    Twenty-eight types of lysozyme-sensitive spores among seven Bacillus species representative of thermophiles, mesophiles, and psychrophiles were obtained spanning a 3,000-fold range in moist-heat resistance. The resistance within species was altered by demineralization of the native spores to protonated spores and remineralization of the protonated spores to calcified spores and by thermal adaptation at maximum, optimum, and minimum sporulation temperatures. Protoplast wet densities, and there...

  20. Evaluating the effectiveness of heat-resistant cast steel filtration from the results of structure examinations

    OpenAIRE

    As?anowicz M.; O?ci?owski A.; Stacha?czyk J.; Wieliczko P.

    2007-01-01

    Filtration guarantees castings characterised by high quality and free from any non-metallic inclusions, which are formed at the stage of melting and pouring of liquid metal. This article discusses the problem of the effectiveness of filtration process taking as an example heat-resistant cast steel poured into ceramic moulds. In investigations, foamed zircon filters made by FerroTerm Sp. z o.o. The effectiveness of filtration was described and examined using the results of metallographic exami...

  1. Polyphasic taxonomy of the heat resistant ascomycete genus Byssochlamys and its Paecilomyces anamorphs

    DEFF Research Database (Denmark)

    Samson, R.A.; Houbraken, J.; Varga, J.; Frisvad, Jens Christian

    2009-01-01

    Byssochlamys and related Paecilomyces strains are often heat resistant and may produce mycotoxins in contaminated pasteurised foodstuffs. A comparative study of all Byssochlamys species was carried out using a polyphasic approach to find characters that differentiate species and to establish accurate data on potential mycotoxin production by each species. Phylogenetic analysis of the ITS region, parts of the P-tubulin and calmodulin genes, macro- and micromorphological examinations and analysis ...

  2. Dependence of heat resistance of Drosophila on ambient temperature and relationship of this property to mutation process

    International Nuclear Information System (INIS)

    It has been demonstrated that thermosensitvity of the gametes in Drosophila line T correlates with the heat resistance of the flies. This property of the gametes is determined during ontogenesis, depending on the temperature during development and not by genotypic preadaptation as such, i.e., affinity of the females to the heat resistance line T. The ability of females to acquire heat resistance during the adult phase (in the first three days after emergence), i.e., by acclimatization to a temperature different from the temperature during development does not change the response of the gametes to extreme temperature which had developed during ontogenesis under a particular temperature

  3. Heat resistance of Listeria monocytogenes in vacuum packaged pasteurized fish fillets.

    Science.gov (United States)

    Ben Embarek, P K; Huss, H H

    1993-11-01

    The heat resistance of two strains of Listeria monocytogenes in sous-vide cooked fillets of cod and salmon was investigated. Fish sticks of 5 g were inoculated, vacuum-packed and heated at different combinations of time and temperature (58-80 degrees C). Time-temperature combinations allowing survival and time-temperature combinations at which the bacteria were destroyed, were used to determine D- and z-values. D-values were in the range of what has been published for other food products. D60-values were between 1.95 and 4.48 min depending on the strain and the fish. Both strains were one-four-times more heat resistant in salmon than in cod, showing the importance of the heating menstruum. This difference may be due to the higher fat content in salmon as compared to cod. Z-values were calculated to be 5.65 and 6.4 degrees C, respectively, for the two strains. The suitability of methods for heat resistance experiments and the survival of L. monocytogenes in sous-vide cooked fish fillets are discussed. PMID:8268058

  4. Long-term creep properties of hastelloy XR in simulated high-temperature gas-cooled reactor helium

    International Nuclear Information System (INIS)

    Creep tests of Hastelloy XR (a modified version of the conventional Hastelloy X) were carried out in simulated high-temperature gas-cooled reactor (HTGR) helium at 800, 900 and 1,000degC. The test results up to about 50,000 h showed no significant degradation in creep properties. The creep-rupture strength obtained through long-term tests was above the level corresponding to the design allowable creep-rupture stress of the High-Temperature Engineering Test Reactor. The values of the stress exponent were 4.5 to 5.7 when the stress dependence of the steady-state creep rate was expressed in terms of the Norton equation. It is judged that dominant creep process is dislocation creep. Rupture lives could be estimated with sufficient accuracy using Larson-Miller parameter. Carburization during creep in simulated HTGR helium did not degrade creep properties of Hastelloy XR. Internally formed cracks were initiated at sites of precipitates at grain boundaries, growing nearly perpendicular to the stress axis. Two phases, Cr-rich carbide and Mo-rich carbide, co-existed in specimens after long-term creep tests. (author)

  5. Eutectic solidification of binary alloys

    International Nuclear Information System (INIS)

    The eutectic is a common multiphase metallurgical constituent. Yet all previous theories of eutectic reaction shared one shortcoming - they lacked an adequate understanding of the eutectic grain structure. Focusing on metallography, Dnepropetrovsk school of thought founded by K.P. Bunin has devised a new concept of eutectic structure formation relying on findings in solidification of Fe-, Al-, Ti-, Cu-, Zn-, Pb- and Sn-base eutectic alloys. Eutectic solidification of binary alloys has been found to occur by joint cooperative growth of finely branched dendrites of the eutectic constituents. A eutectic grain is a two-phase bicrystal whose morphology is determined by the crystallochemical nature of the eutectic's base constituent. Based on studies into genesis and morphology of eutectics, new families of eutectic-type alloys were developed, such as deformable white irons, Boralloys (high-boron wear resistant iron alloys), Ticads (heat resistant titanium-silicon alloys), and Gasars (porous metallic materials for a wide variety of applications). (author)

  6. Development of Semi-Stochastic Algorithm for Optimizing Alloy Composition of High-Temperature Austenitic Stainless Steels (H-Series) for Desired Mechanical and Corrosion Properties.

    Energy Technology Data Exchange (ETDEWEB)

    Dulikravich, George S.; Sikka, Vinod K.; Muralidharan, G.

    2006-06-01

    The goal of this project was to adapt and use an advanced semi-stochastic algorithm for constrained multiobjective optimization and combine it with experimental testing and verification to determine optimum concentrations of alloying elements in heat-resistant and corrosion-resistant H-series stainless steel alloys that will simultaneously maximize a number of alloy's mechanical and corrosion properties.

  7. Formation Mechanism of Type IV Failure in High Cr Ferritic Heat-Resistant Steel-Welded Joint

    Science.gov (United States)

    Liu, Y.; Tsukamoto, S.; Shirane, T.; Abe, F.

    2013-10-01

    The mechanism of type IV failure has been investigated by using a conventional 9Cr ferritic heat-resistant steel Gr.92. In order to clarify the main cause of type IV failure, different heat treatments were performed on the base metal in order to change the prior austenite grain (PAG) size and precipitate distribution after applying the heat-affected zone (HAZ) simulated thermal cycle at the peak temperature of around A c3 ( A c3 HAZ thermal cycle) and postweld heat treatment (PWHT). The microstructural evolution during the A c3 HAZ thermal cycle and PWHT was investigated by means of scanning electron microscope (SEM), electron backscatter diffraction (EBSD), electron probe microanalysis (EPMA), and transmission electron microscope (TEM). It was found that M23C6 carbides were scarcely precipitated at the newly formed fine PAG, block, and lath boundaries in A c3 HAZ-simulated Gr.92, because the carbide forming elements such as Cr and C were segregated at the former PAG and block boundaries of the base metal. On the other hand, if all the boundaries were covered by sufficient M23C6 carbides by homogenization of the alloying elements prior to applying the HAZ thermal cycle, the creep strength was much improved even if the fine PAG was formed. From these results, it is concluded that fine-grained microstructure cannot account for the occurrence of type IV failure, and it only has a small effect during long-term creep. The most important factor is the precipitate formation behavior at various boundaries. Without sufficient boundary strengthening by precipitates, the microstructure of A c3 HAZ undergoes severe changes even during PWHT and causes premature failure during creep.

  8. Modern structural magnesium alloys with rare earth metals

    International Nuclear Information System (INIS)

    Discussed is the possibility to enhance the strength properties of the magnesium alloys, when various rare-earth metals are used as the alloying admixtures. It is shown, that the value of the rare-earth metal solubility in a solid magnesium solution is the determinant factor for the strength and heat-resistance. The strengthening effect during ageing becomes important in the alloys containing considerable amounts of the rare-earth metals. A conclusion is drawn that, out of all the magnesium-rare earth metal alloys, the alloys with samarium, gadolinium, terbium and dysprosium are the most promising

  9. Study on microstructure of pulse laser welding on dissimilar materials hastelloy C-276 and 316L

    International Nuclear Information System (INIS)

    To estimate the reliability of laser welding components of AP1000 and study the distribution of elements and microstructure of dissimilar weld of Hastelloy C-276 and 316L welded by Nd: YAG pulse laser, the microstructure, element distribution and phase of the weld were systematically analyzed by optical microscope, electron probe x ray micro-analyser and other analysis, measuring and test instruments. The results show that the gain of microstructure of weld is refined, and tiny equiaxed grains are in the center and columnar grains are near the weld edge. Heat-affected zones are very narrow on two sides of the weld joint. According to macro distribution of elements, there are three zones in the weld. Element compositions vary drastically on two sides of the weld and become uniform in the center. Micro-segregation of elements exists and Mo enriched at the grain boundary of the weld is observed. Austenite is the main microstructure of the weld and little delta ferrite is found. (authors)

  10. Fatigue Performance of TBCs on Hastelloy X Substrate During Cyclic Bending

    Science.gov (United States)

    Musalek, Radek; Kovarik, Ondrej; Tomek, Libor; Medricky, Jan; Pala, Zdenek; Hausild, Petr; Capek, Jiri; Kolarik, Kamil; Curry, Nicholas; Bjorklund, Stefan

    2015-10-01

    Our previous experiments with low-cost steel substrates confirmed that individual steps of conventional thermal barrier coating (TBC) deposition may influence fatigue properties of the coated samples differently. In the presented study, testing was carried out for TBC samples deposited on industrially more relevant Hastelloy X substrates. Samples were tested after each step of the TBC deposition process: as-received (non-coated), grit-blasted, bond-coated (NiCoCrAlY), and bond-coated + top-coated yttria-stabilized zirconia (YSZ). Conventional atmospheric plasma spraying (APS) was used for deposition of bond coat and top coat. In addition, for one half of the samples, dual-layer bond coat was prepared by combination of high-velocity air-fuel (HVAF) and APS processes. Samples were tested in the as-sprayed condition and after 100 hours annealing at 980 °C, which simulated application-relevant in-service conditions. Obtained results showed that each stage of the TBC manufacturing process as well as the simulated in-service heat exposure may significantly influence the fatigue properties of the TBC coated part. HVAF grit-blasting substantially increased the fatigue performance of the uncoated substrates. This beneficial effect was suppressed by deposition of APS bond coat but not by deposition of dual-layer HVAF + APS bond coat. All heat-treated samples showed again enhanced fatigue performance.

  11. 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.

  12. Corrosion and stress corrosion cracking of high-performance alloys in simulated acidizing environments to 3500F

    International Nuclear Information System (INIS)

    Laboratory corrosion and stress corrosion cracking tests were performed on commercially produced 1020 carbon steel; HASTELLOY alloys 535, G-3, C-276, and B-2; CABOT alloy No. 825; and alloys 28 and 904L in simulated acidizing environments containing NaCl, HCl, HCOOH, HF, and/or MgCl2. A commercial inhibitor provided excellent corrosion inhibition of the high-performance alloys at the boiling point and good inhibition in 15% HCl at 3500F. The use of high- performance alloys offers additional protection to corrosion over carbon steels in the acidizing environments. Non-HCl-containing acidizing environments were not nearly as corrosive as the HCl-containing environments. Stress corrosion cracking was observed in H2S-containing environments in HASTELLOY alloy B-2 and in HF-containing environments in the low nickel- and molybdenum-containing austenitic alloys such as alloy 904L, alloy 28 and alloy 535. Otherwise, no stress corrosion cracking was observed in the other alloys in the 24-hour tests

  13. Segregation in welded nickel-base alloys

    International Nuclear Information System (INIS)

    Segregation effects have been investigated in nickel-base alloys monel 400, inconel 625, hastelloy C-276 and incoloy 825, test welded under controlled conditions. Deviations from the normal composition have been observed to varying extents in the welded zone of these alloys. Least effect of this type occurred in Monel 400 where the content of Cu increased in some of the areas. Enhancement of Al and Ti has been found over large areas in the other alloys which has been attributed to the formation of low melting slag. Another common feature is the segregation of Cr, Fe or Ti, most likely in the form of carbides. Enrichment of Al, Ti, Nb, Mb, Mo, etc., to different amounts in some of the areas of these materials is in- terpretted in terms of the formation of gamma prime precipitates or of Laves phases. (author)

  14. Effect of structure factors on the restriction of production possibility of economical articles of complex nickel alloys by casting and hot working of ingots

    International Nuclear Information System (INIS)

    Possibilities of conventional casting and hot working techniques are analyzed for further improvement of production of high nickel alloys with elevated heat resistance. Analysis of investigation results has shown that progress achieved in the field of melting and hot working has no further possibilities for nickel alloys with low degree of structure heterogeneity and, therefore, for alloys with low heat resistance. Further development of compositions of nickel alloys on the base of conventional technology is inefficient or impossible from the economic point of view. Thus, the development and application of principally new technological processes is necessary

  15. Cyklic strength of heat-resistant steels and their welded joints

    International Nuclear Information System (INIS)

    Systemized results of tests on cyclic strength of heat-resistant 15Kh2MFA and 15Kh2NMFA vessel steels and their welded joints are presented. Main attention is paid to determination of the influence of such technological factors as purity of the base metal and welded materials, welding technique, peculiarities of geometry of edge preparation for welding etc. On cyclic strength. The effect of one or other factor has been estimated on the base of comparison of endurance characteristics (limits of endurance or longevity at the given level of stress)

  16. Precipitation behavior in a nitride-strengthened martensitic heat resistant steel during hot deformation

    Directory of Open Access Journals (Sweden)

    Wenfeng Zhang

    2015-09-01

    Full Text Available The stress relaxation curves for three different hot deformation processes in the temperature range of 750–1000 °C were studied to develop an understanding of the precipitation behavior in a nitride-strengthened martensitic heat resistant steel (Zhang et al., Mater. Sci. Eng. A, 2015 [1]. This data article provides supporting data and detailed information on how to accurately analysis the stress relaxation data. The statistical analysis of the stress peak curves, including the number of peaks, the intensity of the peaks and the integral value of the pumps, was carried out. Meanwhile, the XRD energy spectrum data was also calculated in terms of lattice distortion.

  17. Heat resistance and local structure of FeCl2-absorbed crosslinked poly(?-glutamic acid)

    International Nuclear Information System (INIS)

    Fiber of Japanese food natto (Bacillus subtilis) is known to be superabsorbent poly(?-glutamic acid) (PGA). NaCl particles precipitate in FeCl2-absorbed crosslinked PGA when heated at crystallization temperature of 320 deg C for 10 to 60 min. After heat treatment the Moessbauer spectrum of FeCl2-crosslinked PGA consists of a quadrupole doublet due to FeCl2 x 2H2O. The Moessbauer spectrum of anhydrous FeCl2 reagent heated under the same condition shows an intense sextet due to ?-Fe2O3. These results prove that the superabsorbent polymer, crosslinked PGA, has higher heat resistance. (author)

  18. Microstructural evolution during creep deformation of an 11CrMoVNb ferritic heat resistant steel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyu-Ho; Park, Dae-Bum [Korea Institute of Science and Technology, Seoul (Korea, Republic of). Materials and Devices Div.; Korea Univ., Seoul (Korea, Republic of). Dept. of Materials Science; Kwun, S.I. [Korea Univ., Seoul (Korea, Republic of). Dept. of Materials Science; Suh, Jin-Yoo; Jung, Woo-Sang [Korea Institute of Science and Technology, Seoul (Korea, Republic of). Materials and Devices Div.

    2010-07-01

    The effect of creep deformation on the microstructural development of an 11CrMoVNb ferritic heat resistant steel during high temperature creep test is investigated. Coarsening behavior of the precipitates, M{sub 23}C{sub 6} and MX, and growth behavior of martensite laths of crept specimens are carefully observed from both gage and grip parts of the specimens in order to discuss the effect of deformation. Particle coarsening and martensite lath widening are pronounced in the gage part due to the creep deformation. (orig.)

  19. Study on Curing Kinetics of Heat-resistant Flexible Polyamide Modified Epoxy Resin Adhesive

    Directory of Open Access Journals (Sweden)

    Hua Li

    2015-04-01

    Full Text Available In order to study the effects of numerous variables affecting the reaction rate of heat-resistant flexible modified epoxy resin adhesive, the curing kinetics of polyamide modified epoxy resin was studied. The heat-resistant flexible modified epoxy resin adhesive cured at room-temperature was prepared with epoxy resin, polysulfide rubber and organosilicone as adhesive component, polyamide as main curing agent and addition of different modified filler and the curing agent containing benzene ring structure. The curing kinetics of polyamide modified epoxy resin was studied by Differential Scanning Calorimetry (DSC at different heating speeds and the characteristic temperatures of the curing process were analyzed and confirmed. the kinetics parameters of activation energy was calculated using Flynn-Wall-Ozawa equation and Kissinger equation, respectively, then the kinetic model of curing reaction was built as d&alpha/dt = 4.38×107 exp (-57740/RT (1-&alpha0.93, the results show that the two-parameter model is adequate to represent the curing reaction process, the model can well describe the curing reaction process of the studied resin. The DSC curves obtained using the experimental data show a good agreement with that theoretically calculated. The research results will provide theoretical basis for the choice of manufacturing process and the optimization of processing window.

  20. Development of heat resistant SiC fibers by radiation curing

    International Nuclear Information System (INIS)

    For the structural members for advanced big projects, such as space shuttles, high temperature gas turbines, nuclear fusion and so on, high strength, high reliability and environment durability are required for the materials. In the case of space ships, also light weight is required. As the material suitable to these requirements, fiber-reinforced ceramic composites (CMC) attract most expectation and attention. In order to overcome the brittleness of new ceramics, CMC has been developed. As the reinforcing fibers which are mainly used for CMC, there are silicon carbide fibers. They are light weight, and have high strength, high modulus of elasticity and excellent heat resistance and oxidation resistance. In this report, 'Nicalon' of which the practical use is most advanced among SiC fibers and its application to ceramic composites are described. Also 'Hi-Nicalon' of which the heat resistance was further improved by utilizing radiation is introduced. The manufacturing method of SiC fibers 'Nicalon' and their characteristics, the application of Nicalon fibers, Nicalon-reinforced ceramic composites like CERASEP and Nicaloceram, and the development of Hi-Nicalon are reported. (K.I.)

  1. Development and properties of new 10Cr-2Mo-V-Nb heat resisting steel

    International Nuclear Information System (INIS)

    For the development of a new ferritic heat resisting steel which shows excellent characteristics in creep rupture strength, weldability, resistance to oxidation, and corrosion resistance to sodium and steam at the service temperature of 5000 to 6000C, extensive studies have been carried out. The main results are as follows: (1) 0.05C-10Cr-2Mo-0.1V-0.05Nb steel is obtained, whose creep rupture strength at 6000C is superior to that of SUS 304 (18-8 stainless steel). (2) This steel comprises two phases: delta-ferrite and tempered martensite. Main precipitates after longer term at 6000 to 7000C are M23C6 and Fe2Mo. Fe2Mo, a stable precipitate in ferrite, contributes to the creep rupture strength at longer term. (3) Ferritic heat resisting steel of this type is promising not only for the boiler tube use but for the fast breeder reactor steam generator use, since it has excellent high temperature strength and the resistance to oxidation and corrosion. (author)

  2. Description of cyclic creep behaviour of heat-resistant steels by means of constitutive equations

    International Nuclear Information System (INIS)

    On the basis of various approaches, constitutive creep equations have been developed which permit prediction over a wide range of the uniaxial creep rupture behaviour of typical heat-resistant steels under conditions of constant stress and under conditions of variable tensile or tension-compression lo[s. Normal creep rupture data are required for derivation of the equation constants. It is possible to make temperature interpolation of the constants defined eg. in 50 C intervals. The uncertainty of the prediction of time-to-rupture or limiting strain under cyclic stresses is not larger if derived with scatter band factors of 0.5 and 2 than that derived using the life-fraction rule together with the factor concept of the relative lifetime. For application of the constitutive equations to four heat-resistant, industrial steels, the KORA program has been developed that permits life predictions for any defined creep rupture processes and includes a calculation module applicable as a lifetime specifying tool. (orig./CB)

  3. Salt Fog Testing Iron-Based Amorphous Alloys

    International Nuclear Information System (INIS)

    Iron-based amorphous alloys are hard and highly corrosion resistant, which make them desirable for salt water and other applications. These alloys can be produced as powder and can be deposited as coatings on any surface that needs to be protected from the environment. It was of interest to examine the behavior of these amorphous alloys in the standard salt-fog testing ASTM B 117. Three different amorphous coating compositions were deposited on 316L SS coupons and exposed for many cycles of the salt fog test. Other common engineering alloys such as 1018 carbon steel, 316L SS and Hastelloy C-22 were also tested together with the amorphous coatings. Results show that amorphous coatings are resistant to rusting in salt fog. Partial devitrification may be responsible for isolated rust spots in one of the coatings. (authors)

  4. Structure of heat affected zones in welded joints of heat resisting steels

    International Nuclear Information System (INIS)

    Weld metal structure of heat affected zones (HAZ) of heat resisting steels 12Kh1MF, 15Kh1M1F, 15Kh1M1FL, 12Kh2M, 12Kh2MFB, 20Kh3MFA, 15Kh2NMFA has been studied. It is shown that during welding of metal with bainite structure the phase transformation ? ? ? in HAZ metal is accompanied with revealing structural heredity effect. In the case of ferrite-bainite structure no structural heredity is observed. At the HAZ region near fusion boundary chamical micoinhomogeneity in the form of network, which is related to analogous in morphology network in weld metal, is observed. These networks of segregatiions are conditioned with diffusion redistribution of elements between ? and ? phases at subsolidus temperatures

  5. Analysis of cyclic plastic response of heat resistant Sanicro 25 steel at ambient and elevated temperatures.

    Czech Academy of Sciences Publication Activity Database

    Polák, Jaroslav; Petráš, Roman; Heczko, Milan; Kruml, Tomáš; Chai, G.

    Amsterdam : Elsevier, 2014 - (Gulagliano, M.; Vergani, L.), s. 68-73 ISSN 1877-7058. - (Procedia Engineering. 74). [ICMFM 2014 International Colloquium on Mechanical Fatigue of Metals /17./. Verbania (IT), 25.06.2014-27.06.2014] R&D Projects: GA ?R(CZ) GA13-23652S Institutional support: RVO:68081723 Keywords : heat resistant steel * Sanicro 25 * cyclic plastic ity * dislocation structure * effect of temperature Subject RIV: JL - Materials Fatigue, Friction Mechanics http://ac.els-cdn.com/S1877705814007966/1-s2.0-S1877705814007966-main.pdf?_tid=8150a71a-543c-11e4-b10e-00000aab0f27&acdnat=1413358137_888616b4b84bb7ddf28dfaee5358a90a

  6. Study of heat resistance of chromium-nickel-manganese ferritic-austenitic steels

    International Nuclear Information System (INIS)

    Effect of chemical composition of austenitic-ferritic steels on their scale resistance at 800, 900 and 1000 deg C was studied. Investigation was conducted for steel of 16 casts, differing with respect to nickel, manganese, as well as chromium contents. Certain steel casts had molybdenum additions. Considerable decrease of heat resistance of chromium-nickel ferritic-austenitic steels with 18-23% Cr and variable nickel contents from 0.2 up to 6.03% in the air in 800-1000 deg C temperature range was noted when manganese content was increased. Positive chromium effect on scale resistance with increase of its concentration in steel from 18 up to 23% is manifested only at certain manganese contents

  7. Characterization of heat resistant mutant strains of Rhizobium sp. [Cajanus] for growth, survival and symbiotic properties.

    Science.gov (United States)

    Nehra, Kiran; Yadav, Attar S; Sehrawat, Anita R; Vashishat, R K

    2007-12-01

    Fourteen heat resistant mutant strains were isolated from a wild-type strain (PP201, Nod(+) Fix(+)) of Rhizobium sp. (Cajanus) by giving it a heat shock of 43°C. These mutant strains showed a greater increase in optical density (O.D.) and a higher viable cell count in both rhizospheric and non-rhizospheric soil at high temperature. Symbiotic studies showed that pigeon pea plants inoculated with a few mutant strains had ineffective nodules (Nod(+) Fix(-)) under controlled temperature (43°C) conditions, but under natural high temperature (40-45°C) conditions, the host plants infected with all the mutant strains showed higher total shoot nitrogen than the plants inoculated with the parent strain. Four mutant strains (HR-3, HR-6, HR-10 and HR-12) were found to be highly efficient for all the symbiotic parameters, and thus have the potential to be used as bioinoculants in the North-Western regions of India during the summer season. PMID:23100686

  8. Evaluating the effectiveness of heat-resistant cast steel filtration from the results of structure examinations

    Directory of Open Access Journals (Sweden)

    As?anowicz M.

    2007-01-01

    Full Text Available Filtration guarantees castings characterised by high quality and free from any non-metallic inclusions, which are formed at the stage of melting and pouring of liquid metal. This article discusses the problem of the effectiveness of filtration process taking as an example heat-resistant cast steel poured into ceramic moulds. In investigations, foamed zircon filters made by FerroTerm Sp. z o.o. The effectiveness of filtration was described and examined using the results of metallographic examinations, including macro- and micro-structure examinations of metal and of cast metal/ceramic filter interface, and measurements of the content of non-metallic inclusions. The methods of investigations were presented, the obtained results were described, and relevant conclusions were drawn, all of them unmistakably indicating a very beneficial effect that filtration has on molten metal quality. ?ód?, Poland, were used.

  9. Estimating the Condition of the Heat Resistant Lining in an Electrical Reduction Furnace

    Directory of Open Access Journals (Sweden)

    Jan G. Waalmann

    1988-01-01

    Full Text Available This paper presents a system for estimating the condition of the heat resistant lining in an electrical reduction furnace for ferrosilicon. The system uses temperature measured with thermocouples placed on the outside of the furnace-pot. These measurements are used together with a mathematical model of the temperature distribution in the lining in a recursive least squares algorithm to estimate the position of 'the transformation front'. The system is part of a monitoring system which is being developed in the AIP-project: 'Condition monitoring of strongly exposed process equipment in thc ferroalloy industry'. The estimator runs on-line, and results arc presented in colour-graphics on a display unit. The goal is to locate the transformation front with an accuracy of +- 5cm.

  10. Microstructural Characterization for Structural Health Monitoring of Heat-Resisting Rotor Steels

    International Nuclear Information System (INIS)

    The typical heat-resisting rotor steels such as 2.25CrMo, 9CrMo and 12CrW steel were experimentally studied in order to understand their materials degradation under high temperature and pressure during the long-term service, and then use the basic studies for the structural health monitoring. In order to monitor the materials degradation, it was conducted by the isothermal aging for 2.25CrMo steel, creep-fatigue for 9CrMo steel and creep for 12Cr steel with the incremental step test. The ultrasonic wave properties, electrical resistivity and coercivity were interpreted in relation to microstructural changes at each material and showed strong sensitivity to the specific microstructural evolution

  11. Development of halogen-free, heat-resistant, low-voltage wire for automotive use

    International Nuclear Information System (INIS)

    The environmental load of our motorized society is of major concern, and includes considerations of recycling of automotive parts as the industrial wastes. The total average length of AV, AVX (electrical wire insulated with PVC, cross-linked PVC), and AEX (electrical wire insulated with cross-linked polyolefin) wires required for the harnesses in modern automobiles is approximately 2,000-3,000 meters per unit. However these electrical wires contain a large amount of halogen, which can generate the smoke and corrosive gas. In response to this problem the authors have developed the electron beam irradiated halogen-free, heat-resistant, low-voltage electrical wire which does not contain any halogen based polymer or flame retardants. The developed wire features the reliability equivalent to AEX wire with minimum environmental load. (Author)

  12. Effects of alpha-tocopherol addition to polymeric coatings on the UV and heat resistance of a fibrous collagen material--chrome-free leather

    Science.gov (United States)

    UV and heat resistance are very important qualities of leather because most leather products are constantly exposed to outdoor environments. In recent years, we have focused on using environmentally friendly antioxidants that will improve the UV and heat resistance of chrome-free leather. Tocopher...

  13. Investigation on multi-element Ni-Cr-Mo-Cu alloying layer by double glow plasma alloying technique

    International Nuclear Information System (INIS)

    This paper describes an investigation of double glow surface alloying of low-carbon steel with Hastelloy C-2000 nickel-based surperalloy. Emphasis is placed on the effect of the source electrode voltage, cathode voltage, working pressure and parallel distance between source electrode and cathode on the chemical composition and physical qualities of surface alloying layer. The results show that the total content of alloy elements, thickness of alloying layer and absorbing alloy element rate have closely related with technological parameters. The combination of SEM and XRD is used to investigate morphology and structure of the multi-element Ni-Cr-Mo-Cu surface alloying layer. The thermodynamic calculation was performed to predict the mole fraction of phase in the alloying layer as function of temperature. The calculated results is in agreement with the observation of microstructure of alloying layer. The corrosion experimental results indicated that the corrosion resistance of alloying layer formed on the stainless steel was super to that of alloying layer formed on the low-carbon steel

  14. Collect Available Creep-Fatigue Data and Study Existing Creep-Fatigue Evaluation Procedures for Grade 91 and Hastelloy XR

    Energy Technology Data Exchange (ETDEWEB)

    Tai Asayama; Yukio Tachibana

    2007-09-30

    This report describes the results of investigation on Task 5 of DOE/ASME Materials Project based on a contract between ASME Standards Technology, LLC (ASME ST-LLC) and Japan Atomic Energy Agency (JAEA). Task 5 is to collect available creep-fatigue data and study existing creep-fatigue evaluation procedures for Grade 91 steel and Hastelloy XR. Part I of this report is devoted to Grade 91 steel. Existing creep-fatigue data were collected (Appendix A) and analyzed from the viewpoints of establishing a creep-fatigue procedure for VHTR design. A fair amount of creep-fatigue data has been obtained and creep-fatigue phenomena have been clarified to develop design standards mainly for fast breeder reactors. Following this, existing creep-fatigue procedures were studied and it was clarified that the creep-fatigue evaluation procedure of the ASME-NH has a lot of conservatisms and they were analyzed in detail from the viewpoints of the evaluation of creep damage of material. Based on the above studies, suggestions to improve the ASME-NH procedure along with necessary research and development items were presented. Part II of this report is devoted to Hastelloy XR. Existing creep-fatigue data used for development of the high temperature structural design guideline for High Temperature Gas-cooled Reactor (HTGR) were collected. Creep-fatigue evaluation procedure in the design guideline and its application to design of the intermediate heat exchanger (IHX) for High Temperature Engineering Test Reactor (HTTR) was described. Finally, some necessary research and development items in relation to creep-fatigue evaluation for Gen IV and VHTR reactors were presented.

  15. Collect Available Creep-Fatigue Data and Study Existing Creep-Fatigue Evaluation Procedures for Grade 91 and Hastelloy XR

    International Nuclear Information System (INIS)

    This report describes the results of investigation on Task 5 of DOE/ASME Materials Project based on a contract between ASME Standards Technology, LLC (ASME ST-LLC) and Japan Atomic Energy Agency (JAEA). Task 5 is to collect available creep-fatigue data and study existing creep-fatigue evaluation procedures for Grade 91 steel and Hastelloy XR. Part I of this report is devoted to Grade 91 steel. Existing creep-fatigue data were collected (Appendix A) and analyzed from the viewpoints of establishing a creep-fatigue procedure for VHTR design. A fair amount of creep-fatigue data has been obtained and creep-fatigue phenomena have been clarified to develop design standards mainly for fast breeder reactors. Following this, existing creep-fatigue procedures were studied and it was clarified that the creep-fatigue evaluation procedure of the ASME-NH has a lot of conservatisms and they were analyzed in detail from the viewpoints of the evaluation of creep damage of material. Based on the above studies, suggestions to improve the ASME-NH procedure along with necessary research and development items were presented. Part II of this report is devoted to Hastelloy XR. Existing creep-fatigue data used for development of the high temperature structural design guideline for High Temperature Gas-cooled Reactor (HTGR) were collected. Creep-fatigue evaluation procedure in the design guideline and its application to design of the intermediate heat exchanger (IHX) for High Temperature Engineering Test Reactor (HTTR) was described. Finally, some necessary research and development items in relation to creep-fatigue evaluation for Gen IV and VHTR reactors were presented.

  16. Influence of marble content in electrode coating on properties of heat resistant weld-up metal

    International Nuclear Information System (INIS)

    The effect of the marble content in the electrode coating on the mechanical properties of weld-up metal and welded joints is studied. The nickel-chrome metal to be welded is additionally alloyed with niobium, molybdenum, tungsten, and rhenium. The investigation results show that variation in the marble content of the coating from 10 to 40% does not appreciably affect the mechanical properties and technological strength of the weld-up metals. An increase in the marble content of electrodes with different alloying systems increases the resistance to hot cracking in a one-phase weld-up metal and reduces it in a two-phase metal. Long-term 100-hr strength of the weld-up metal increases for niobium-alloyed electrodes and reduces in welding with electrodes alloyed with molybdenum

  17. Polyphasic taxonomy of the heat resistant ascomycete genus Byssochlamys and its Paecilomyces anamorphs

    DEFF Research Database (Denmark)

    Samson, R.A.; Houbraken, J.

    2009-01-01

    Byssochlamys and related Paecilomyces strains are often heat resistant and may produce mycotoxins in contaminated pasteurised foodstuffs. A comparative study of all Byssochlamys species was carried out using a polyphasic approach to find characters that differentiate species and to establish accurate data on potential mycotoxin production by each species. Phylogenetic analysis of the ITS region, parts of the P-tubulin and calmodulin genes, macro- and micromorphological examinations and analysis of extrolite profiles were applied. Phylogenetic analyses revealed that the genus Byssochlamys includes nine species, five of which form a teleomorph, i.e. B. fulva, B. lagunculariae, B. nivea, B. spectabilis and B. zollemiae, while four are asexual, namely P. brunneolus, P. divaricatus, P. formosus and P. saturatus. Among these, B. nivea produces the mycotoxins patulin and byssochlamic acid and the immunosuppressant mycophenolic acid. Byssochlamys lagunculariae produces byssochlamic acid and mycophenolic acid and thuschemically resembles B. nivea. Some strains of P saturatus produce patulin and brefeldin A, while B. spectabilis (anamorph P. variotii s.s.) produces viriditoxin. Some micro- and macromorphological characters are valuable for identification purposes, including the shape and size of conidia and ascospores, presence and ornamentation of chlamydospores, growth rates on MEA and CYA and acid production on CREA. A dichotomous key is provided for species identification based on phenotypical characters.

  18. Isolation and characterization of heat-resistant (HR) mutants of Newcastle disease virus.

    Science.gov (United States)

    Iinuma, M; Nishiyama, Y; Hamaguchi, M; Yoshida, T; Nagai, Y; Maeno, K; Matsumoto, T

    1979-01-01

    Heat-resistant (HR) mutants (MR 70 and HR 74) of Newcastle disease virus (NDV) which exhibited significantly higher thermostability in their infectivity than wild-type virus were isolated and characterized. They differ from each other in their plaque morphology; HR 70 produces small turbid plaques, whereas those of HR 74 are large and clear. Cytopathogenicity of these mutants is much lower than that of the wild-type virus in cultured cells such as CEF, LLCMK2 and HeLa cells. Moreover, these HR mutants exhibited extended mean embryo survival times. Synthesis of cellular RNA's and proteins in cells infected with HR mutants was not significantly reduced under conditions in which synthesis of these macromolecules was strongly reduced in cells infected with wild-type virus. No significant differences were observed between HR mutants and wild-type virus in their other phenotypic characteristics such as the capacity for interferon production, growth characteristics at a low multiplicity of infection, and cleavage of viral glycoproteins in infected cells. From these findings, it was suggested that the inhibitory effect of virus infection on cellular macromolecular synthesis is a possible determinant of cytopathogenicity of NDV. PMID:537521

  19. Spatial fluxes and energy distributions of reactor fast neutrons in two types of heat resistant concretes

    International Nuclear Information System (INIS)

    Measurements have been carried out to study the spatial fluxes and energy distributions of reactor fast neutrons transmitted through two types of heat resistant concretes, serpentine concrete and magnetic lemonite concrete. The physical, chemical and mechanical properties of these concretes were checked by well known techniques. In addition, the effect of heating at temperatures up to 500deg C on the crystaline water content was checked by the method of differential thermal analysis. Measurements were performed using a collimated beam of reactor neutrons emitted from a 10 MW research reactor. The neutron spectra transmitted through concrete barriers of different thickness were measured by a scintillation spectrometer with NE-213 liquid organic scintillator. Discrimination against undesired pulses due to gamma-rays was achieved by a method based on pulse shape discrimination technique. The operating principle of this technique is based on the comparison of two weighted time integrals of the detector signal. The measured pulse amplitude distribution was converted to neutron energy distribution by a computational code based on double differentiation technique. The spectrometer workability and the accuracy of the unfolding technique were checked by measuring the neutron spectra of neutrons from Pu-?-Be and 252Cf neutron sources. The obtained neutron spectra for the two concretes were used to derive the total cross sections for neutrons of different energies. (orig.)

  20. Preparation of heat-resistance waterborne coatings containing synthetic hectorite clay

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.K. [Kyungil University, Kyungsan (Korea); Lee, B.K. [Kyungpook National University, Taegu (Korea)

    2001-02-01

    Three different composition of waterborne coatings (WBC-0, WBC-1, WBC-2) were prepared by the compounding of synthesized hectorite clay (SHC) from the hydrothermal reaction with acryl latex and coating additives. The pH, solution viscosity and solid content of WBCs were investigated, and the rheological properties with the shear rate measured by the rheometer. Also, the thermal stability and the transmittance of the films casted by WBCs were investigated by thermogravimetry analysis and UV-VIS spectrophotometer, respectively. WBC-2 containing 8 phr SHC showed the phase transition of sol and gel with the shear rate, that is, the thixotropic property, and the storage stability of WBC-2 increased by means of its phenomenon. The initial decomposition temperature and the transmittance of films casted by WBC-1 and WBC-2 increased in range of 99.6 {approx}110.2{sup 0} deg. C and 20.9 {approx} 21.7% than the commercial WBC, respectively. As a consequence, WBC containing SHC showed increasing effect both the heat-resistance and the solution viscosity by the water swellable clay. (author). 14 refs., 4 tabs., 5 figs.

  1. Characterization and radiation response of a heat-resistant variant of V79 cells

    International Nuclear Information System (INIS)

    A thermoresistant variant of the established cell line V79-S171-W1 was isolated after treatment with nitrosoguanidine and repeated heat treatments at 42.6 to 430C, and showed an enhanced ability to survive at 42.6, 43.5, and44.50C. The rates of inactivation of the normal and heat-resistant lines differed by approximately a factor of 2 over this temperature range. This level of thermoresistance was stable for the first 80 doublings, but was lost by 120 doublings. This may have been due to a reversion to the normal V79 line since there was no continuous selection pressure and the thermoresistant variant, which was designated at HR7, had a longer average doubling time. Transient thermotolerance was induced in both the V79 and HR7 cells by a 10-min expsure to 44.50C. After 3 hr incubation at 370C, both cell lines had an identical sensitivity to further exposure to 44.50C. Thus the long-term thermoresistance of the HR7 cells may be due to a permanent induction of a low level of thermotolerance. The (ionizing) radiation survival curves and the ability to repair sublethal radiation damage were identical for the thermoresistance variant and the parent cell line

  2. Characterization and radiation response of a heat-resistant variant of V79 cells

    International Nuclear Information System (INIS)

    A thermoresistant variant of the established cell line V79-S171-W1 was isolated after treatment with nitrosoguanidine and repeated heat treatments at 42.6 to 43 degrees C, and showed an enhanced ability to survive at 42.6, 43.5, and 44.5 degrees C. The rates of inactivation of the normal and heat-resistant lines differed by approximately a factor of 2 over this temperature range. This level of thermoresistance was stable for the first 80 doublings, but was lost by 120 doublings. This may have been due to a reversion to the normal V79 line since there was no continuous selection pressure and the thermoresistant variant, which was designated at HR7, had a longer average doubling time. Transient thermotolerance was induced in both the V79 and HR7 cells by a 10-min exposure to 44.5 degrees C. After 3 hr incubation at 37 degrees C, both cell lines had an identical sensitivity to further exposure to 44.5 degrees C. Thus the long-term thermoresistance of the HR7 cells may be due to a permanent induction of a low level of thermotolerance. The (ionizing) radiation survival curves and the ability to repair sublethal radiation damage were identical for the thermoresistant variant and the parent cell line

  3. Heat resisting T92/P92 steel, its welding and properties of welded joints

    International Nuclear Information System (INIS)

    Basic characteristics of the T/P92 steel are given and its creep strength in comparison with other heat resisting steel grades. The influence of welding thermal cycles on the properties of simulated heat affected zones has been examined and it was found, that in a wide range of t8/5 cooling times martensite is present with a hardness higher than 400 HV and a low notch toughness. But joints made of T92 tubes (?51,0 x 7.0 mm) and pipes P92 (? 219 x 20 mm) have been TIG welded with the P92-IG wire by using FOX 92 stick electrodes in the horizontal (PC) and vertical up (PF and H-L045) positions and post-weld heat treated. Examination results of the test joints have revealed their good mechanical and plastic properties, a hardness not exceeding 285 HV, a high Charpy V notch toughness of the parent material and HAZ. The notch toughness of welds was lower, but it satisfies the requirements of the technical inspection societies. (author)

  4. Morphological Change of the Surface Groove on a Heat Resistant Alloy Due to Thermal and Thermo-Mechanical Cycling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Feng-Xun; Kang, Ki Ju [Chonnam National Univ., Gwangju (Korea, Republic of); Sun, Shin Kyu [Industry Academic Cooperation Fundation, Sunchon National Univ., Sunchon (Korea, Republic of)

    2007-07-01

    The existence of grooves on the surface of bond coat has significant effect on the instability of thermal barrier system. In this work, the thermal-mechanical fatigue experiments were performed under various thermal and mechanical loads for FeCralloy specimens with and without yttrium dopant to observe the deformation of surface grooves. The effect of temperature, fatigue load and the ratio of curvature on the deformation of grooves were investigated. As the results, it has been found that the higher load level and the higher curvature ratio induces the larger deformation near the grooves. However, the addition of yttrium dopant induces the adverse results.

  5. Temperature effect on nickel base alloy corrosion in geologic formations

    International Nuclear Information System (INIS)

    Hastelloys and inconels for containers used for long term storage of high-level radioactive wastes in deep geologic repositories are examined. The temperature effect on the corrosion behaviour of some nickel base alloys is investigated in the present study using electrochemical and surface analysis techniques. The most important effect concerns the susceptibility to pitting corrosion of the alloys in chloride media. The pitting potential and the pit development kinetics under controlled potential increase markedly with temperature. The concentration depth profiles on surface films are characteristic of an impoverishment of the alloying elements when the temperature increases. In particular, the observed decrease of the molybdenum content seems to be due to its selective dissolution in the tested geological waters

  6. Magnesium Cermets and Magnesium-Beryllium Alloys

    International Nuclear Information System (INIS)

    The paper describes some results of work on the development of magnesium-magnesium oxide cermets and of super heat-resistant magnesiumberyllium alloys produced by powder metallurgical methods. The introduction of even a minute quantity of finely dispersed magnesium oxide into magnesium results in a strengthening of the material, the degree of which increases with increased magnesium oxide concentration, although variation of this concentration within the limits of 0.3 to 5 wt.% has a comparatively slight effect on the corresponding variation in the short-term strength over the whole range of temperatures investigated. At 20oC, in the case of the cermets, ?? = 28 to 31 kg/mm2 and ? = 3 .5 to 4.5%; at 500oC ?? = 2.6 to 3.2 kg/mm2 and ? =30 to 40%. The positive effect of the finely dispersed oxide phase is particularly evident in protracted tests. For magnesium cermets, ? (300)/100 = 2.2 kg/mm2. Characteristic of the mixtures is the high thermal stability of the strength properties, linked chiefly with the thermodynamic stability of the strength-giving oxide phase in the metal matrix. The use of powder metallurgical methods has yielded super heat-resistant magnesium-beryllium alloys containing heightened concentrations of beryllium (PMB alloys). In their strength characteristics PMB alloys are close to Mg-MgO cermets, but the magnesium-beryllium alloys have a degree and duration of resistance to high temperature oxidation which exceeds the corresponding qualities of the magnesium alloys at present known. Thus, in air of 580oC, PMB alloys with 2 to 5% beryllium maintain a high resistance to oxidation for a period of over 12000 to 14000 h. This long-term heat resistance is chiefly a result of the amount of beryllium in the alloy, and increases with increasing beryllium content. PMB alloys are also marked by high resistance to short bursts of overheating. Magnesium cermets and magnesium-beryllium alloys, with their enhanced high-temperature stability, are capable of finding extensive application in various branches of technology. (author)

  7. An all-fiber, polarized, core-pumped heat-resistant thulium-doped master oscillator power amplifier

    International Nuclear Information System (INIS)

    We present an all-fiber, polarized, core-pumped heat-resistant thulium-doped master oscillator power amplifier (MOPA) system. The laser operated at a wavelength of 1926.7 nm with a spectral linewidth of less than 70 pm. For a repetition rate of 100 kHz, a maximum average power of 750 mW with a slope efficiency of 48.8% and pulse duration of 41 ns was achieved. Even without active cooling, no observable thermal effects occurred when the laser was operated at room temperature. To the best of our knowledge, this core-pumped heat-resistant MOPA configuration is the first reported in the 2 ?m region. (paper)

  8. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella typhimurium on Chicken Breast Fillet during Cooking.

    DEFF Research Database (Denmark)

    de Jong, Aarieke E I; van Asselt, Esther D

    2012-01-01

    The aim of this research was to determine the decimal reduction times of bacteria present on chicken fillet in boiling water. The experiments were conducted with Campylobacter jejuni, Salmonella, and Escherichia coli. Whole chicken breast fillets were inoculated with the pathogens, stored overnight (4°C), and subsequently cooked. The surface temperature reached 70°C within 30 sec and 85°C within one minute. Extremely high decimal reduction times of 1.90, 1.97, and 2.20 min were obtained for C. jejuni, E. coli, and S. typhimurium, respectively. Chicken meat and refrigerated storage before cooking enlarged the heat resistance of the food borne pathogens. Additionally, a high challenge temperature or fast heating rate contributed to the level of heat resistance. The data were used to assess the probability of illness (campylobacteriosis) due to consumption of chicken fillet as a function of cooking time. The data revealed that cooking time may be far more critical than previously assumed.

  9. Superconductivity mediated by a soft phonon mode: specific heat, resistivity, thermal expansion and magnetization of YB6

    CERN Document Server

    Lortz, R; Tutsch, U; Abe, S; Meingast, C; Popovich, P; Knaffo, W; Shitsevalova, N; Paderno, Y B; Junod, A; Paderno, Yu. B.

    2006-01-01

    The superconductor YB6 has the second highest critical temperature Tc among the boride family MBn. We report measurements of the specific heat, resistivity, magnetic susceptibility and thermal expansion from 2 to 300 K, using a single crystal with Tc = 7.2 K. The superconducting gap is characteristic of medium-strong coupling. The specific heat, resistivity and expansivity curves are deconvolved to yield approximations of the phonon density of states, the spectral electron-phonon scattering function and the phonon density of states weighted by the frequency-dependent Grueneisen parameter respectively. Lattice vibrations extend to high frequencies >100 meV, but a dominant Einstein-like mode at ~8 meV, associated with the vibrations of yttrium ions in oversized boron cages, appears to provide most of the superconducting coupling and gives rise to an unusual temperature behavior of several observable quantities. A surface critical field Hc3 is also observed.

  10. Surface modification of the parts mode from heat resistant steel by high-current pulsed electron beam

    International Nuclear Information System (INIS)

    By electron Auger spectroscopy, scanning electron microscopy and X-ray structure analysis, the effect of regimes of intense pulsed electron beam irradiation on corrosion resistance of heat resistant ferritic and austenitic steels with carbide hardening under thermal cycling has been investigated. It is shown that corrosion resistance of the steels can be enhanced by 200-300% as a results of electron-beam treatment with a following vacuum annealing

  11. Heat-resistant DNA tile arrays constructed by template-directed photoligation through 5-carboxyvinyl-2?-deoxyuridine

    OpenAIRE

    Tagawa, Miho; Shohda, Koh-ichiroh; Fujimoto, Kenzo; Sugawara, Tadashi; Suyama, Akira

    2007-01-01

    Template-directed DNA photoligation has been applied to a method to construct heat-resistant two-dimensional (2D) DNA arrays that can work as scaffolds in bottom-up assembly of functional biomolecules and nano-electronic components. DNA double-crossover AB-staggered (DXAB) tiles were covalently connected by enzyme-free template-directed photoligation, which enables a specific ligation reaction in an extremely tight space and under buffer conditions where no enzymes work efficiently. DNA nanos...

  12. Sustainable, heat-resistant and flame-retardant cellulose-based composite separator for high-performance lithium ion battery

    OpenAIRE

    Jianjun Zhang; Liping Yue; Qingshan Kong; Zhihong Liu; Xinhong Zhou; Chuanjian Zhang; Quan Xu; Bo Zhang; Guoliang Ding; Bingsheng Qin; Yulong Duan; Qingfu Wang; Jianhua Yao; Guanglei Cui; Liquan Chen

    2014-01-01

    A sustainable, heat-resistant and flame-retardant cellulose-based composite nonwoven has been successfully fabricated and explored its potential application for promising separator of high-performance lithium ion battery. It was demonstrated that this flame-retardant cellulose-based composite separator possessed good flame retardancy, superior heat tolerance and proper mechanical strength. As compared to the commercialized polypropylene (PP) separator, such composite separator presented impro...

  13. Optimum Irrigation Scheduling for CRIS-134, A New Heat Resistant Cotton Variety of Sindh in Sakrand Conditions

    Directory of Open Access Journals (Sweden)

    A. M. Memon

    2001-01-01

    Full Text Available A field experiment was conducted to evaluate the different dates of initial irrigation and later irrigation frequencies on seedcotton yield of CRIS-134, an advance heat resistant variety. On an average, data revealed that CRIS-134 significantly responded to first irrigation at 45 days after planting (DAP and yielded highest (2429 kg ha -1. As regards interval between subsequent irrigations, results revealed that averagely CRIS-134 produced significantly highest yield of 2230 kg ha -1 at every two weeks interval.

  14. Sources and risk factors for contamination, survival, persistence, and heat resistance of Salmonella in low-moisture foods.

    Science.gov (United States)

    Podolak, Richard; Enache, Elena; Stone, Warren; Black, Darryl G; Elliott, Philip H

    2010-10-01

    Sources and risk factors for contamination, survival, persistence, and heat resistance of Salmonella in low-moisture foods are reviewed. Processed products such as peanut butter, infant formula, chocolate, cereal products, and dried milk are characteristically low-water-activity foods and do not support growth of vegetative pathogens such as Salmonella. Significant food safety risk might occur when contamination takes place after a lethal processing step. Salmonella cross-contamination in low-moisture foods has been traced to factors such as poor sanitation practices, poor equipment design, and poor ingredient control. It is well recognized that Salmonella can survive for long periods in low-moisture food products. Although some die-off occurs in low-moisture foods during storage, the degree of reduction depends on factors such as storage temperature and product formulation. The heat resistance of Salmonella is affected by many factors, mostly by strain and serotypes tested, previous growth and storage conditions, the physical and chemical food composition, test media, and the media used to recover heat-damaged cells. Salmonella heat resistance generally increases with reducing moisture. Care must be taken when applying published D- and z-values to a specific food process. The product composition and heating medium and conditions should not be significantly different from the product and process parameters used by the processors. PMID:21067682

  15. Electromagnetic property of SiO2-coated carbonyl iron/polyimide composites as heat resistant microwave absorbing materials

    International Nuclear Information System (INIS)

    Heat resistant microwave absorbing materials were prepared by compression molding method, using polyimide resin as matrix and SiO2 coated carbonyl iron (CI) as filler. The SiO2 coated CI particles were prepared by Stober process. The microwave absorbing properties and the effect of heat treatment on the electromagnetic properties of SiO2 coated CI/polyimide composites were investigated. When the content of SiO2 coated CI is 60 wt%, the value of minimum reflection loss decreases from ?25 dB to ?33 dB with the thickness increases from 1.5 mm to 2.1 mm. According to the thermal-gravimetric analyses (TGA) curves, the polyimide matrix can be used at 300 °C for long time. The complex permittivity of the composites slightly increases while the complex permeability almost keeps constant after heat treatment at 300 °C for 10 h, which indicating that the composites can be used at elevated temperature as microwave absorbing materials at the same time have good heat resistance and microwave absorption. - Highlights: • Polyimide as matrix and SiO2 coated carbonyl iron as filler. • The SiO2 coated CI shows good absorbing properties. • The composites have good heat resistance

  16. Induction of Heat Resistance in Wheat Coleoptiles by 4-Hydroxybenzoic Acid: Connection with the Generation of Reactive Oxygen Species

    Directory of Open Access Journals (Sweden)

    Yastreb T.O.

    2012-08-01

    Full Text Available The effect of 4-hydroxybenzoic acid (4-HBA on resistance of coleoptiles of 4-day-old etiolated seedlings of wheat (Triticum aestivum L., cv. Elegiya to damaging heating (10 min at 43°C and possible dependence of this effect on changes in the activities of enzymes producing and scavenging reactive oxygen species (ROS were investigated. Treatment of coleoptiles with 10 ?M 4-HBA resulted in enhancing of superoxide anion-radical generation and maintaining of hydrogen peroxide content there in. Increasing of the rate of ROS production was significantly suppressed by inhibitors of NADPH oxidase (?-naphthol and peroxidase (salicylhydroxamic acid. Under the influence of 4-HBA the activities of superoxide dismutase and apoplastic forms of peroxidase were increased. The activity of oxalate oxidase and catalase has not changed. Exogenous 4-HBA improved coleoptiles heat resistance and its effects were comparable with the influence of salicylic acid. Antioxidant agent BHT (butylhydroxytoluene, inhibitors of NADPH oxidase and peroxidase significantly reduced the increasing of wheat coleoptiles heat resistance, caused by 4-HBA action. It was concluded that 4-HBA influence on coleoptiles heat resistance is realized with the ROS mediation.

  17. Heat-resistant thin film photoelectric converter with diffusion blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Takada, Jun; Yamaguchi, Minori; Tawada, Yoshihisa.

    1990-06-26

    The photoelectric converter of this invention comprises a semiconductor, an electrode, and a diffusion-blocking layer provided between the semiconductor and at least one electrode. An object of this invention is to provide a thin film photoelectric converter which has good heat resistance, in order to avoid the reduction in quality owing to the diffusion of metal or metallic compound from the electrode to the semiconductor layer, on the condition that the ohmic loss in the backing electrode and the reflection loss of light at the backing electrode are not increased. The component of the diffusion-blocking layer is selected from among such materials as metal silicides, silicide-forming metals, and metals from Groups IVA and VA of the periodic table. A preferable thickness of the diffusion-blocking layer is 5 to 500 angstroms. The semiconductor can be of the p-i-n, p-n, or Schottky type, and can be 0.02 to 100 {mu}m thick. For a semiconductor which comes into contact with the diffusion-blocking layer, n-type is preferable because it offers great improvements in the characteristics of the photoelectric converter. The electrode on the light-incident side is transparent and made of a metallic compound such as In{sub 2}O{sub 3}, SnO{sub 2}, Cd{sub x}SnO{sub y} (x=0.5 to 2, y=2 to 4) or the like. The backing electrode material is selected to have a suitable conductivity and reflectivity; such materials include Ag, Au, Al or Cu. The invention also discloses a method of preparing the thick film photoelectric converter, and examples are provided to illustrate the preparation of various embodiments of the invention. 2 figs., 1 tab.

  18. Study on functional heat-resistant ceramics SiC using small angle neutron scattering

    International Nuclear Information System (INIS)

    The mechanical properties of functional heat-resistant silicon carbide SiC ceramics are significantly influenced by the concentration and dimensions of pores. 3 SiC samples with different densities were sintered with different kind and amount of additives (such as Al2O3, B4C and C) using different sintering conditions of the Department of Material Science and Engineering at the University of Science and Technology in Beijing. Small angle neutron scattering measurements for 3 SiC samples were carried out at C1-2 SANS instrument of the University of Tokyo in Japan Atomic Energy Research Institute. The neutron data with 8 and 16 in of secondary flight path and 10 and 7 A of neutron wave length respectively have been obtained. After deduction of background measurement and transmission correction, both neutron data were linked up with each other. The cubic patterns of 3 neutron data with Q range from 0.0028 - 0.05 A-1 are almost with axial symmetry. It shows that the shape of pores, whose dimensions are relative to the Q range, is almost spherical. For spherical particles (or pores) we can obtain an expression of size distribution directly, using Mellin Transform (J. Appl. Phys. 45, 1974, 46.). According to our calculating program for the expression, the size distribution of pores for 3 samples were obtained. The average size (? 190 A) of pores for hot-pressed SiC sample with more density is smaller than others (? 210 A). It seems to be the reason why the density of hot-pressed SiC sample is higher than no-hot-pressed sample. (author)

  19. Microstructure and magnetic properties of mechanically alloyed FeSiBAlNi (Nb) high entropy alloys

    International Nuclear Information System (INIS)

    In this paper, the effects of milling duration and composition on the microstructure and magnetic properties of equi-atomic FeSiBAlNi and FeSiBAlNiNb high entropy alloys during mechanical alloying have been investigated using X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, transmission electron microscopy and alternating gradient magnetometry. The amorphous high entropy alloys have been successfully fabricated using the mechanical alloying method. The results show that the Nb addition prolongs the milling time for the formation of the fully FeSiBAlNi amorphous phase and decreases the glass forming ability. However, FeSiBAlNiNb amorphous high entropy alloy has the higher thermal stability and heat resisting properties. Moreover, the as-milled FeSiBAlNi(Nb) powders are soft-magnetic materials indicated by their low coercivity. The saturation magnetization of the as-milled FeSiBAlNi(Nb) powders decreases with prolonging of the milling time and shows the lowest value when the amorphous high entropy alloys are formed. It suggests that the as-milled products with solid solution phases show the better soft-magnetic properties than those with fully amorphous phases. The Nb addition does not improve the soft-magnetic properties of the FeSiBAlNi high entropy alloys. Rather, both amorphous high entropy alloys have similar soft-magnetic properties after a long milling time. - Highlights: ?FeSiBAlNi(Nb) amorphous high entropy alloys (HEAs) were fabricated by the MA method. ?Nb decreases GFA and enhances thermal stability and heat resisting properties. ?FeSiBAlNi HEA shows the better soft magnetism than that of the FeSiBAlNiNb HEA. ?FeSiBAlNi(Nb) HEAs show the better soft magnetism than that of their amorphous HEAs. ?The existent mode of solid solution phases of the HEAs affects soft magnetism

  20. Fractal analysis and atomic force microscopy measurements of surface roughness for Hastelloy C276 substrates and amorphous alumina buffer layers in coated conductors

    International Nuclear Information System (INIS)

    In coated conductors, surface roughness of metallic substrates and buffer layers could significantly affect the texture of subsequently deposited buffer layers and the critical current density of superconductor layer. Atomic force microscopy (AFM) is usually utilized to measure surface roughness. However, the roughness values are actually relevant to scan scale. Fractal geometry could be exerted to analyze the scaling performance of surface roughness. In this study, four samples were prepared, which were electro polished Hastelloy C276 substrate, mechanically polished Hastelloy C276 substrate and the amorphous alumina buffer layers deposited on both the substrates by ion beam deposition. The surface roughness, described by root mean squared (RMS) and arithmetic average (Ra) values, was analyzed considering the scan scale of AFM measurements. The surfaces of amorphous alumina layers were found to be fractal in nature because of the scaling performance of roughness, while the surfaces of Hastelloy substrates were not. The flatten modification of AFM images was discussed. And the calculation of surface roughness in smaller parts divided from the whole AFM images was studied, compared with the results of actual AFM measurements of the same scan scales.

  1. Fractal analysis and atomic force microscopy measurements of surface roughness for Hastelloy C276 substrates and amorphous alumina buffer layers in coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Feng, F.; Shi, K.; Xiao, S.-Z.; Zhang, Y.-Y. [Applied Superconductivity Research Center, Department of Physics, Tsinghua University, Beijing 100084 (China); Zhao, Z.-J. [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Wang, Z., E-mail: wangzhi@bit.edu.cn [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Wei, J.-J.; Han, Z. [Applied Superconductivity Research Center, Department of Physics, Tsinghua University, Beijing 100084 (China)

    2012-02-01

    In coated conductors, surface roughness of metallic substrates and buffer layers could significantly affect the texture of subsequently deposited buffer layers and the critical current density of superconductor layer. Atomic force microscopy (AFM) is usually utilized to measure surface roughness. However, the roughness values are actually relevant to scan scale. Fractal geometry could be exerted to analyze the scaling performance of surface roughness. In this study, four samples were prepared, which were electro polished Hastelloy C276 substrate, mechanically polished Hastelloy C276 substrate and the amorphous alumina buffer layers deposited on both the substrates by ion beam deposition. The surface roughness, described by root mean squared (RMS) and arithmetic average (R{sub a}) values, was analyzed considering the scan scale of AFM measurements. The surfaces of amorphous alumina layers were found to be fractal in nature because of the scaling performance of roughness, while the surfaces of Hastelloy substrates were not. The flatten modification of AFM images was discussed. And the calculation of surface roughness in smaller parts divided from the whole AFM images was studied, compared with the results of actual AFM measurements of the same scan scales.

  2. The effect of extrusion and annealing regimes on mechanical properties of powder Mo-Zr-B alloys

    International Nuclear Information System (INIS)

    The influence of extrusion and heat treatment conditions on mechanical properties of powder molybdenum alloys at 20-1800 deg C in the form of 40-45 mm rods is studied. The alloys are produced using the mixture of Mo and 0.1-2.0%ZrB2. It is shown that the worked molybdenum alloy with 2% ZrB2 exhibits high hardening ability. The optimal composition of a heat resistant molybdenum alloy is selected. This alloy possesses sufficient ductility at 20 deg C both in deformed and recrystallized states

  3. Summary of studies on hot corrosion of iron-based alloys by sodium sulfate in O2/SO2/SO3 environment

    OpenAIRE

    Zhang, Yunshu; Wu, Weitao

    1993-01-01

    Iron base heat-resistant alloys are widely used in high temperature environments, especially in civil and industrial boilers and other combustors. This type of alloys was found to undergo hot corrosion when covered with a sulfate deposit. Recent studies of sulfate-deposit-induced hot corrosion of iron-base alloys are selectively reviewed in this paper. Emphasis is placed on studies of the hot corrosion occurring at relatively low temperatures, concerning the thermodynamics of the formation of...

  4. Biological indicators for low temperature steam formaldehyde sterilization: effect of defined media on sporulation, germination index and moist heat resistance at 110 degrees C of Bacillus strains.

    Science.gov (United States)

    Hoxey, E V; Soper, C J; Davies, D J

    1985-02-01

    Choice of a biological indicator depends upon selecting a strain with the optimum balance of desirable properties. Screening 20 strains of Bacillus spp. for sporulation on three defined media has shown the wide variation that occurs in requirements for sporulation and properties of the resultant spores. Comparison of germination index and moist heat resistance of resultant spores suggest that a combination of high germination index, high heat resistance and linear inactivation may not be possible. PMID:3980302

  5. Ocorrência de fungos filamentosos termo-resistentes em polpa de tomate envasada assepticamente Occurrence of heat resistant molds in tomato pulp packed aseptically

    Directory of Open Access Journals (Sweden)

    Flávio BAGLIONI

    1999-05-01

    Full Text Available Este trabalho teve como objetivo principal determinar a ocorrência de fungos filamentosos termo-resistentes durante o processamento asséptico de polpa de tomate (8° BRIX. Durante o período de safra de tomate foram feitas amostragens em 9 lotes (3 no início, 3 no pico e 3 em fim de safra e no período de entresafra em 5 lotes. Foi feita a enumeração de fungos termo-resistentes nas amostras coletadas durante as diferentes etapas do processo asséptico de cada lote. Foram obtidas contagens médias relativamente baixas, variando entre This work aimed at determining the occurrence of heat resistant molds during the aseptic processing of tomato pulp (8° BRIX. During tomato harvest, 9 lots were sampled (3 at the beginning, 3 at the apex and 3 at the end of harvest and other 5 lots were sampled between harvest. For each lot, the enumeration of heat resistant molds was carried out in samples collected during the aseptic process. The mean count of heat resistant molds was relatively low, ranging from <1 to 8CFU/100mL of sample. The higher counts were observed in the raw material and the pre-wash and transportation water. Fifty strains of heat resistant molds detected in the enumeration procedure were isolated, codified and stocked. One-month-old spores of each isolate were submitted to different heat shocks to select the most heat resistant mold. The most heat resistant isolated strain (survived 100° C/25 minutes was identified as Neosartorya fischeri.

  6. Kinetics of chromium evaporation from heat-resisting steel under reduced pressure

    Directory of Open Access Journals (Sweden)

    C. Kolmasiak

    2012-07-01

    Full Text Available This paper describes a kinetic analysis of the process of chromium evaporation from ferrous alloys smelted under reduced pressure. The study discussed comprised determination of the liquid phase mass transfer coefficient as well as the value of the constant evaporation rate. By applying these values as well as the values of the overall mass transfer coefficient estimated based on the relevant experimental data, the fractions of resistance of the individual process stages were established.

  7. Wrought stainless steel compositions having engineered microstructures for improved heat resistance

    Science.gov (United States)

    Maziasz, Philip J [Oak Ridge, TN; Swindeman, Robert W [Oak Ridge, TN; Pint, Bruce A [Knoxville, TN; Santella, Michael L [Knoxville, TN; More, Karren L [Knoxville, TN

    2007-08-21

    A wrought stainless steel alloy composition includes 12% to 25% Cr, 8% to 25% Ni, 0.05% to 1% Nb, 0.05% to 10% Mn, 0.02% to 0.15% C, 0.02% to 0.5% N, with the balance iron, the composition having the capability of developing an engineered microstructure at a temperature above 550.degree. C. The engineered microstructure includes an austenite matrix having therein a dispersion of intragranular NbC precipitates in a concentration in the range of 10.sup.10 to 10.sup.17 precipitates per cm.sup.3.

  8. Heat Resistance in Liquids of Enterococcus spp., Listeria spp., Escherichia coli, Yersinia enterocolitica, Salmonella spp. and Campylobacter spp

    Directory of Open Access Journals (Sweden)

    Sörqvist S

    2003-03-01

    Full Text Available The aim of the work was to collect, evaluate, summarize and compare heat resistance data reported for Campylobacter, Enterococcus, Escherichia, Listeria, Salmonella and Yersinia spp. The work was limited to resistance in liquids with pH values 6–8. Results obtained under similar experimental conditions were sought. Thermal destruction lines for the various bacterial groups studied were constructed using log10 D values and treatment temperatures. There was a good linear relationship between log10 D and temperature with Escherichia coli, listerias and salmonellas. For campylobacters, enterococci and yersinias the relationships were weaker but, nevertheless, present. Using the slopes of the lines and their 95% confidence limits, z values and their 95% confidence limits were calculated. z values were compared with z values obtained from reports. The equations for the lines were also used for calculation of predicted means of D values at various treatment temperatures. 95% confidence limits on predicted means of D values and on predicted individual D values were also calculated. Lines and values are shown in figures and tables. Differences in heat resistance noted between and within the bacterial groups studied are discussed.

  9. Reel-to-reel electropolishing of Ni alloy tapes for IBAD template

    International Nuclear Information System (INIS)

    Ni alloy tape is electropolished to be used as a metal substrate for fabrication of IBAD (ion-Beam Assisted Deposition)-MgO texture template fur HTS coated conductor. Electropolishing is needed to obtain a very smooth surface of Ni alloy tape because the in-plane texture of templates is sensitive to the roughness of metal substrate. The critical current of YBCO coated conductor depends on the texture of YBCO that depends on the texture of the IBAD MgO layer. And so the smoothness of the metal substrate is directly related to the superconducting properties of the coated conductor. In this study, we have prepared a reel-to-reel electropolishing apparatus to polish the Ni alloy tapes for IBAD. Various electropolishing conditions were investigated to improve the surface roughness. Hastelloy tape is continuously electropolished with high polishing current density (0.5 - 2 A/cm2) and fast processing time (1 - 3 min). Polished hastelloy tapes have surface roughness(RMS) of below 1 nm on a 5 X 5 ??2 from AFM and SEM.

  10. Comparative corrosion resistance of some high-nickel, chromium-molybdenum alloys

    International Nuclear Information System (INIS)

    The comparative corrosion resistance of alloy C-276 (UNS N10276), alloy 625 (UNS N06625), Hastelloy C-22 (UNS N06022), and ALLCORR (UNS N06110) was studied in sodium chloride-ferric chloride solutions, and nitric, hydrochloric, formic, and sulfuric acids, some with additives such as HF. Butt-welded coupons were used to determine the corrosion characteristics of weldments. In addition to weight loss measurements, crevice and pitting attack were evaluated. For a complex chemical facility to vitrify high-level radioactive wastes, a corrosion study was conducted to select materials of construction for handling the various process streams, several of which were unusually corrosive. Two high-nickel, chromium-molybdenum alloys, C-276 (UNS N10276) and 625 (UNS N06625), were acceptable for much of the processing

  11. Tensile properties of a nickel-base alloy subjected to surface severe plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Tian, J.W. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN (United States); Dai, K. [Quality Engineering and Software Technology, East Hartford, CT 06108 (United States); Villegas, J.C. [Intel Corporation, Chandler, AZ (United States); Shaw, L. [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, Storrs, CT (United States)], E-mail: leon.shaw@uconn.edu; Liaw, P.K. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN (United States); Klarstrom, D.L. [Haynes International, Inc., Kokomo, IN (United States); Ortiz, A.L. [Departamento de Ingenieria Mecanica, Energetica y de los Materiales, Universidad de Extremadura, 06071 Badajoz (Spain)

    2008-10-15

    A surface severe plastic deformation (S{sup 2}PD) method has been applied to bulk specimens of HASTELLOY C-2000 alloy, a nickel-base alloy. The mechanical properties of the processed C-2000 alloy were determined via tensile tests and Vickers hardness measurements, whereas the microstructure was characterized using scanning electron microscopy, transmission electron microscopy, and X-ray diffractometry. The improved tensile strength was related to the nanostructure at the surface region, the residual compressive stresses, and the work-hardened surface layer, all of which resulted from the S{sup 2}PD process. To understand the contributions of these three factors, finite element modeling was performed. It was found that the improved tensile strength could be interpreted based on the contributions of nano-grains, residual stresses, and work hardening.

  12. The effect of ultrasonic machining on the mechanical properties of nickel base alloys

    International Nuclear Information System (INIS)

    The effect of ultra-sound upon the mechanical properties of nickel base heat- and corrosion-resistant alloys was studied on cast and deformed metal. The tests were carried out for static tension, twisting and impact strength at temperatures of hot mechanical working (900 to 1200 deg C). The investigations indicate that a finer structure of the multi-component nicel base alloy obtained through ultrasonic treatment of a solidifying metal results in the improvement of the plasticity of the cast and the deformed metal. The ultrasonic treatment improved the heat-resistance of the EP109, EP220, EP881 alloys by 10 to 15 %

  13. Solute Transport Proteins and the Outer Membrane Protein NmpC Contribute to Heat Resistance of Escherichia coli AW1.7?

    OpenAIRE

    Ruan, Lifang; Pleitner, Aaron; Gänzle, Michael G.; McMullen, Lynn M.

    2011-01-01

    This study aimed to elucidate determinants of heat resistance in Escherichia coli by comparing the composition of membrane lipids, as well as gene expression, in heat-resistant E. coli AW1.7 and heat-sensitive E. coli GGG10 with or without heat shock. The survival of E. coli AW1.7 at late exponential phase was 100-fold higher than that of E. coli GGG10 after incubation at 60°C for 15 min. The cytoplasmic membrane of E. coli AW1.7 contained a higher proportion of saturated and cyclopropane fat...

  14. Study on high temperature design methodology of heat-resistant materials for GEN-IV systems

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Woo Seog; Kim, D. W.; Kim, S. H.; Kim, W. G.; Kim, J. H.; Park, D. G.; Yoon, J. H.; Lee, H. Y.; Hing, J. H

    2005-08-15

    Analysis of the existing high temperature design and assessment codes such as US(ASME-NH,Draft Code Case for Alloy 617), France(RCC-MR), UK(R5), Japan(BDS/DDS/FDS) for Gen IV reactor structure has been carried out. In addition the scope and fields for research and development is needed in the future have been defined. For assessing the high temperature creep cracks, time dependent fracture mechanics (TDFM) parameters of the C and Ct were analyzed. The creep propagation data were obtained from the creep crack growth tests for type 316LN stainless steels, and creep crack growth testing machine for Gen-IV system up to 950 .deg. C was set up. Damage mechanism and causes for creep-fatigue were investigated. The difference between prediction creep-fatigue life and experimental life were investigated. Material properties for analysis creep-fatigue damage were recommended. The assessment procedure (Draft) on creep-fatigue crack initiation has been developed based on the technical appendix A16 of French RCC-MR code. Ultrasonic wave signal against creep ruptured specimens of type 316LN stainless steel was obtained. It was identified that creep damage can be evaluated by ultrasonic method. The NDT techniques evaluated include Barkhausen noise, magnetic hysteresis parameters, positron annihilation, X-ray diffraction and small angle neutron scattering. Experimental procedure and evaluation method of material integrity were developed through the fracture toughness test of Cr-Mo steel.

  15. Study on high temperature design methodology of heat-resistant materials for GEN-IV systems

    International Nuclear Information System (INIS)

    Analysis of the existing high temperature design and assessment codes such as US(ASME-NH,Draft Code Case for Alloy 617), France(RCC-MR), UK(R5), Japan(BDS/DDS/FDS) for Gen IV reactor structure has been carried out. In addition the scope and fields for research and development is needed in the future have been defined. For assessing the high temperature creep cracks, time dependent fracture mechanics (TDFM) parameters of the C and Ct were analyzed. The creep propagation data were obtained from the creep crack growth tests for type 316LN stainless steels, and creep crack growth testing machine for Gen-IV system up to 950 .deg. C was set up. Damage mechanism and causes for creep-fatigue were investigated. The difference between prediction creep-fatigue life and experimental life were investigated. Material properties for analysis creep-fatigue damage were recommended. The assessment procedure (Draft) on creep-fatigue crack initiation has been developed based on the technical appendix A16 of French RCC-MR code. Ultrasonic wave signal against creep ruptured specimens of type 316LN stainless steel was obtained. It was identified that creep damage can be evaluated by ultrasonic method. The NDT techniques evaluated include Barkhausen noise, magnetic hysteresis parameters, positron annihilation, X-ray diffraction and small angle neutron scattering. Experimental procedure and evaluation method of material integrity were developed through the fracture toughness test of Cr-Mo steel

  16. [Analysis of individual changes in heat resistance of clones of Daphnia magna at the initial stages of cultivation].

    Science.gov (United States)

    Mironova, A P

    2012-01-01

    30 clones of water fleas have been studied on the basis of heat resistance (HR) of these organisms at the initial stages of cultivation. Ten clones died before the appearance of the offspring in F2; the remaining clones were multiplied successfully and produced subsequent generations. Based on the change in the individual HR level of the clones in F1 as compared with ancestors, it was concluded a violation of the mechanisms of physiological homeostasis in the population of dead clones. In the remaining clones, there were a high negative correlation between the initial individual resistance level and its change in F1 and F2 and a pronounced narrowing of the variability diapason in F1. In this animal group, the significant lability of individual-level resistance was observed as well as its ability to regulate the shift of its resistance, which provided an efficient work of the mechanisms of physiological homeostasis. PMID:23461033

  17. Thermal activation energy analysis of structural instability of heat resisting materials and computerized simulation of fracture processes

    International Nuclear Information System (INIS)

    Methods for investigation of processes of heat resistant material fracture are considered. In particular, the thermoactivation analysis in combination with approaches of solid body mechanics are used for forecasting long-term strenqth and creep. The idea of thermoactivation nature of deformation and damage processes resulted in a possibility of plotting a general parametric basic curve for durability and minimum creep rate according to the results of short-term tensile tests. The hypothesis on descrete change of deformation mechanisms and, therefore, discrete nature of curves of long-term strength with thermoactivation stress constant for each section was the basis for structural computerized simulation. Calculation data on damage accumulation at different stresses (50, 200 and 300 MPa) as well as calculated and experimental curves of long-term strength of 1Kh2M steel for 400-550 deg C temperatures are presented

  18. A Multiscale Approach to Deformation and Fracture of Heat-Resistant Steel Under Static and Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Vladimir GLIHA

    2013-03-01

    Full Text Available Regularities of static and cyclic deformation, damage and fracture of heat-resistant steel 25Kh1M1F, based on the approaches of physical mesomechanics and 3D interferometry method, are presented in this paper. The applicability of these techniques for different hierarchy levels of deformation was studied. The investigation of scanning microscope photos was conducted for several dissipative structures, fragmentation of the material, localisation of macrodeformation and subsequent failure on macro- and mesolevel. It is shown that the used modern techniques of experimental analysis are very efficient in understanding deformation and damage evolution in materials.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3821

  19. Evaluation of the same heat Hastelloy XR as the material used for high-temperature components of the High-Temperature Engineering Test Reactor, 2

    International Nuclear Information System (INIS)

    A series of tension, Charpy impact and creep tests was carried out on two sorts of plate materials with 15 mm and 60 mm in thickness obtained from typical one of 30 heats of Hastelloy XR manufactured as the component material of the High-Temperature Engineering Test Reactor (HTTR). Creep test temperatures were 850, 900, 950 and 1000degC, and the maximum creep test time was 3371.4 h. The results obtained are as follows: (1) Both of plate materials tested exhibit acceptable tensile strength and tensile ductility as the structural material of the high-temperature components of the HTTR. (2) The plate material with 15 mm in thickness exhibits enough toughness, while toughness of the plate material with 60 mm in thickness is inferior to that of the plate material with 15 mm in thickness. (3) Both of plate materials tested possess the creep rupture strength beyond not only the expected minimum stress-to-rupture values, SR, but also the expected mean stress-to-rupture values of the material strength standards of Hastelloy XR. The materials also possess enough creep rupture ductility. (author)

  20. The outlook for application of the thermo-hydrogen treatment of titanium alloys

    International Nuclear Information System (INIS)

    The fields of application and prospects for thermal hydrogen treatment (THT) as a basis for titanium alloy hydrogen technology are under consideration. Titanium alloy THT flow sheets include three basis stages: saturation with hydrogen; subjection of hydrogen alloyed material to heating; hydrogen desorption during vacuum heat treatment to the point where hydrogen embrittlement is excluded. The results of THT application with the aim of enhancement of processing and operating properties of semiproducts and articles of various type alloys, new alloys designing and production of new semiproducts of structural and heat resistant alloys (VT5L, VT6L, VT3-1, VT9, VT18U, VT25U, VT22I, Ti-12% Cr) are reported

  1. Predictive model for the reduction of heat resistance of Listeria monocytogenes in ground beef by the combined effect of sodium chloride and apple polyphenols

    Science.gov (United States)

    We investigated the combined effect of three internal temperatures (57.5, 60, and 62.5C) and different concentrations (0 to 3.0 wt/wt %) of sodium chloride (NaCl) and apple polyphenols (APP), individually and in combination, on the heat-resistance of a five-strain cocktail of Listeria monocytogenes ...

  2. Optimization of the diffusion bonding parameters for the production of a micro heat exchanger from Hastelloy {sup registered} C-22 {sup registered}; Optimierung der Diffusionsschweissparameter von Hastelloy {sup registered} C-22 {sup registered} zur Herstellung von Mikrowaermetauschern

    Energy Technology Data Exchange (ETDEWEB)

    Basuki, Widodo Widjaja

    2008-10-15

    The subject of this work is to optimize the diffusion bonding parameters for Hastelloy {sup registered} C-22 {sup registered} by means of a diffusion bonding model for the production of a cross flow micro heat exchanger for chemical applications. Due to the corrosion resistance, the microstructures of the material should not be strongly changed during the diffusion bonding process. The mechanical properties of the bonding unit (e.g. tensile strength, ductility) should be as high as possible. To achieve this objective the preliminary investigations concerning the micro structural and mechanical properties are necessary. The investigations of the micro structural properties show that a diffusion bonding process is impossible in the temperature range of 700 C < T < 1050 C without the precipitation of Mo-rich phase and the formation of metal carbide at the welding seam, which can worsen the ductility of the bonding sample. At temperature above T > 1050 C a substantial grain growth takes place which lowers the strength of the material. Below a temperature of 700 C a diffusion bonding process can be conducted only with very high compressive force and bonding time. It was found that the optimal temperature for the bonding process is at 1050 C. Additionally, it can be recognized that the sheet metal surface in the as-received condition is contaminated with 600 nm thick Al2O3 layer, which has to be ground before the bonding process. By the investigation of the mechanical properties the temperature dependence of yield strength and the creep law will obtained, which served as input parameters for the diffusion bonding model. For the prediction of an optimized parameter set a computer program based on the diffusion bonding model is implemented, which contains all transport mechanisms also present in the sinter process of metals. The model calculation yielded an optimized parameter set of 1050 C, 26 MPa and 3.6 h for the surface roughness produced by a P-2500 abrasive paper. This parameter set is verified in the diffusion bonding experiments on the unstructured sheet metal samples for different values of compression stress, bonding time and surface roughness. A short bonding process is not possible due to the carbide formation at the welding seam as identified by the AES analysis. The bonding with this parameter set results a good welding seam with small remaining pores. The bonding specimens show that the tensile strength is as high as that of base material and the ductility is being more than 50 % of the base material. By using this optimized parameter set on the cross flow micro heat exchanger similar part, the inhomogenous distribution of the compression stress at the joint interface is considered by means of a FEM computation. Hence the compression stress on the total area of the part amount to 11.7 MPa. The diffusion bonding experiments with the structured sheet metals show likewise high strength and ductility, with microstructures and welding seam quality comparable to the diffusion bonding with sheet metals without channel structures. (orig.)

  3. Intensification of methods for steel and alloy plastic working used in turboengineering

    International Nuclear Information System (INIS)

    Results of investigation into the operations of forge chopping and setting of specimens of the 18Kh11MNFB(EhP29), 31Kh19N9MVBT(EhI572), and 15Kh11MF steels under vibration loading are presented. It is shown that vibration loading improves the ductility of specimens of heat-resisting steels and alloys on the average by 16% and reduces the heterogeneity deformation

  4. [Superplastic forming of titanium alloy denture base].

    Science.gov (United States)

    Okuno, O; Nakano, T; Hamanaka, H; Miura, I; Ito, M; Ai, M; Okada, M

    1989-03-01

    Ti-6Al-4V alloy has both excellent biocompatibility and superior mechanical properties. This Ti-6Al-4V can be deformed greatly and easily at the superplastic temperature of 800 degrees C to 900 degrees C. The superplastic forming of Ti-6Al-4V was made to apply to fabrication of denture base. Almost the same procedure as for dental casting mold was employed in producing the superplastic forming die by the improved phosphate bonded investment. In the pressure vessel of heat resistant alloy, Ti-6Al-4V plate was formed superplastically on the die by argon gas pressure at 850 degrees C. The fit of superplactic forming Ti-6Al-4V denture base was better than that of casting Co-Cr alloy denture bases. The Ti-6Al-4V alloy might react a little with the die. Because micro Vikers hardness of the cross-section did not go up too much near the surfaces. Even just after being formed, the surfaces were much smoother than that of Co-Cr alloy casting. The tensile strength and yield strength of superplastic forming Ti-6Al-4V were higher than those of Co-Cr castings. The elongation was about 10%. These results show that superplastic forming of Ti-6Al-4V would be suitable for a denture base. PMID:2603084

  5. Attack of high-strength, oxidation-resistant alloys during in-can melting of simulated waste glasses

    International Nuclear Information System (INIS)

    The restistance of candidate canister alloys to penetration under the most severe conditions expected during in-can melting was directly proportional to the chromium content of the alloy, and inversely proportional to the Na2O content of the glass melt. Specimens were exposed for 24 hours, which is the time required for in-can melting full-size waste-glass forms based on tests carried out at Pacific Northwest Laboratories (PNL) and at SRL. The penetration resistance to Frit 211 at 11500C for 24 hours of most alloys tested was satisfactory. The amount of penetration would not affect the integrity of the waste form. Inconel 625, Hastelloy X, and Inconel 601 were penetrated 100 mils by a glass composed of 65 wt % Frit 21 and 35 wt % composite sludge (with uranium) at 11500C for only 7 hours. This amount of penetration of an in-can melting canister would not be satisfactory. 12 figures

  6. Effect of Mg-Zn-Nd spherical quasi-crystals on microstructure and mechanical properties of ZK60 alloy

    OpenAIRE

    Zhang Jinshan; Wang Xing; Zhang Zhaoguang

    2011-01-01

    To improve the strength, toughness, heat-resistance and deformability of magnesium alloy, the microstructure and mechanical properties of ZK60 alloy strengthened by Mg-Zn-Nd spherical quasi-crystal phase (I-phase) particles were investigated. Mg40Zn55Nd5 (I-phase) particles in addition to ?-Mg, MgZn phase and MgZn2 phases can be obtained in ZK60-based composites under normal casting condition by the addition of quasi-crystal containing Mg-Zn-Nd master alloy. The experimental results show that...

  7. Carbon corrosion of alloys at high temperature

    Scientific Electronic Library Online (English)

    D.J., Young; J., Zhang.

    2013-02-01

    Full Text Available Alloys used at high temperature must resist both creep and corrosion. Design for corrosion resistance is based on the formation of a slow-growing, protective oxide scale by selective oxidation of an appropriate alloy component, usually chromium or aluminium. A successful scale will exclude other cor [...] rodents, notably carbon, which can otherwise cause extremely rapid corrosion at high temperatures. Selective oxidation of an alloy component necessarily lowers the concentration of that metal in the alloy subsurface region. Under thermal cycling conditions, mechanical damage to the scale leads to renewed oxide growth and accelerated alloy depletion. Eventually, a point is reached where diffusion of a corrodent into the alloy becomes competitive with the outward diffusion of alloy metal to repair the protective scale. Two examples of alloy failure by carbon attack are considered. In the steam cracking (pyrolysis) process, centrifugally cast tubes of heat-resisting alloy are exposed to a gas stream of hydrocarbon and steam, at a carbon activity of unity. Formation and repair of the surface chromia scale causes alloy depletion, Kirkendall void formation, and subsequent internal precipitation of chromium-rich carbides. Their formation makes chromia scale formation much more difficult, and generates internal stress. Eventually, the tubes fail by creep rupture. In other processes (e.g. steam reforming, heat treatment), synthesis gases are supersaturated with carbon at intermediate temperatures. Once the alloy's protective scale is breached, carbon attacks the depleted substrate. In the case of ferritic alloys, it forms a surface scale of Fe3C. As this scale thickens, the supersaturated carbon precipitates as graphite within its outer regions. The resulting volume expansion causes disintegration of the cementite in a process known as metal dusting. In the case of austenitic alloys, no metal carbide is formed. Instead, carbon dissolves in the depleted metal to diffuse inward and precipitate as graphite within the metal matrix. Again, volume expansion causes disintegration of the alloy, and metal dusting results. Dusting occurs at an extraordinarily rapid rate, and leads to failure by section loss or even penetration.

  8. Molecular methods used to estimate thermal inactivation of a prototype human norovirus: more heat resistant than previously believed?

    Science.gov (United States)

    Escudero-Abarca, B I; Rawsthorne, H; Goulter, R M; Suh, S H; Jaykus, L A

    2014-08-01

    Two molecular-based methods for estimating capsid integrity as a proxy for virus infectivity were used to produce thermal inactivation profiles of Snow Mountain virus (SMV), a prototype human norovirus (HuNoV). Monodispersed virus suspensions were exposed to 77, 80, 82 and 85 °C for various times, pre-treated with either propidium monoazide (PMA) or RNase, and subjected to RNA isolation followed by RT-qPCR amplification. D-values were 25.6 ± 2.8, 3.1 ± 0.1, 0.7 ± 0.04 and 0.2 ± 0.07 min at 77, 80, 82 and 85 °C, respectively for PMA-treated SMV; and 16.4 ± 0.4, 3.9 ± 0.2 0.9 ± 0.3 and 0.12 ± 0.00 min at 77, 80, 82 and 85 °C, respectively for RNase-treated SMV. Corresponding zD values were 3.80 °C and 3.71 °C for PMA and RNase-treated virus, respectively. Electron microscopy data applied to heat-treated virus-like particles supported this relatively high degree of thermal resistance. The data suggest that SMV is more heat resistant than common cultivable HuNoV surrogates. Standardized thermal inactivation methods (such as milk pasteurization) may not be stringent enough to eliminate this virus and perhaps other HuNoV. PMID:24750817

  9. Development of cold isostatic pressing graphite module for a heat-resistant lower hybrid current drive antenna

    International Nuclear Information System (INIS)

    Development of a plasma facing module using Cold Isostatic Pressing Graphite (CIPG) was successfully achieved for use in driving a heat-resistant Lower Hybrid Current Drive (LHCD) antenna. A thin stainless film (10 ?m), a molybdenum film (10 ?m), and a copper film (50 ?m) were overlaid on the CIPG materials, the CIPG surfaces were successfully coated with the Cu-layer by diffusion bonding method. This module whose length is 206 mm, has four waveguides, and a water cooling channel. High rf-power long pulse operations with water cooling were successfully tested up to 250 kW (125 MW/m2)/700 s, a stationary temperature and vacuum pressure was performed. But the maximum rf transmission power was limited to 47 MW/m2 for a plasma facing module using Carbon Fiber Composite (CFC) due to poor Cu-plating, a power density large by more than a factor 2.5 was achieved with the CIPG module. The rf power density which meets the requirement of the rf electric field of 5 kV/cm for a design of the LHCD antenna in International Thermonuclear Experimental Reactor (ITER) was successfully performed

  10. Scorpion Venom Heat-Resistant Peptide Attenuates Glial Fibrillary Acidic Protein Expression via c-Jun/AP-1.

    Science.gov (United States)

    Cao, Zhen; Wu, Xue-Fei; Peng, Yan; Zhang, Rui; Li, Na; Yang, Jin-Yi; Zhang, Shu-Qin; Zhang, Wan-Qin; Zhao, Jie; Li, Shao

    2015-11-01

    Scorpion venom has been used in the Orient to treat central nervous system diseases for many years, and the protein/peptide toxins in Buthus martensii Karsch (BmK) venom are believed to be the effective components. Scorpion venom heat-resistant peptide (SVHRP) is an active component of the scorpion venom extracted from BmK. In a previous study, we found that SVHRP could inhibit the formation of a glial scar, which is characterized by enhanced glial fibrillary acidic protein (GFAP) expression, in the epileptic hippocampus. However, the cellular and molecular mechanisms underlying this process remain to be clarified. The results of the present study indicate that endogenous GFAP expression in primary rat astrocytes was attenuated by SVHRP. We further demonstrate that the suppression of GFAP was primarily mediated by inhibiting both c-Jun expression and its binding with AP-1 DNA binding site and other factors at the GFAP promoter. These results support that SVHRP contributes to reducing GFAP at least in part by decreasing the activity of the transcription factor AP-1. In conclusion, the effects of SVHRP on astrocytes with respect to the c-Jun/AP-1 signaling pathway in vitro provide a practical basis for studying astrocyte activation and inhibition and a scientific basis for further studies of traditional medicine. PMID:26134308

  11. Development of cold isostatic pressing graphite module for a heat-resistant lower hybrid current drive antenna

    Science.gov (United States)

    Maebara, Sunao; Goniche, Marc; Kazarian, Fabienne; Seki, Masami; Ikeda, Yoshitaka; Imai, Tsuyoshi; Beaumont, Bertrand

    2005-05-01

    Development of a plasma facing module using Cold Isostatic Pressing Graphite (CIPG) was successfully achieved for use in driving a heat-resistant Lower Hybrid Current Drive (LHCD) antenna. A thin stainless film (10?m), a molybdenum film (10?m), and a copper film (50?m) were overlaid on the CIPG materials, the CIPG surfaces were successfully coated with the Cu-layer by diffusion bonding method. This module whose length is 206mm, has four waveguides, and a water cooling channel. High rf-power long pulse operations with water cooling were successfully tested up to 250kW (125MW/m2)/700s, a stationary temperature and vacuum pressure was performed. But the maximum rf transmission power was limited to 47MW/m2 for a plasma facing module using Carbon Fiber Composite (CFC) due to poor Cu-plating, a power density large by more than a factor 2.5 was achieved with the CIPG module. The rf power density which meets the requirement of the rf electric field of 5kV/cm for a design of the LHCD antenna in International Thermonuclear Experimental Reactor (ITER) was successfully performed.

  12. Influence of salicylic and succinic acids on antioxidant enzymes activity, heat resistance and productivity of Panicum miliaceum L.

    Directory of Open Access Journals (Sweden)

    Miroshnichenko N.N.

    2011-05-01

    Full Text Available The influence of treatment of millet (Panicum miliaceum L. seeds with the solutions of salicylic and succinic acids on the heat resistance of plantlets and activity of antioxidant enzymes – superoxide dismutase (SOD, catalase and peroxidase – in them have been investigated. In the micro-field experiment the influence of these acids on the millet yield was estimated. The action of salicylic (10 ?M and succinic (1 mM acids caused the increase of plantlets resistance to the damaging heating that expressed in the rise of relative quantity of survived plantlets in 5 days after heating at the temperature of 47°? and in the reduced content of lipid peroxidation product malonic dialdehyde during the poststress period. The increase of activity of SOD, catalase and peroxidase took place in millet plantlets under the influence of salicylic and succinic acids. The increase of productivity of millet grain under the action of salicylic and succinic acids on 13,3-52,0 and 6,4-38,8% respectively depending on weather conditions in the field experiments was noted.

  13. Precipitation behavior and martensite lath coarsening during tempering of T/P92 ferritic heat-resistant steel

    Science.gov (United States)

    Xu, Lin-qing; Zhang, Dan-tian; Liu, Yong-chang; Ning, Bao-qun; Qiao, Zhi-xia; Yan, Ze-sheng; Li, Hui-jun

    2014-05-01

    Tempering is an important process for T/P92 ferritic heat-resistant steel from the viewpoint of microstructure control, as it facilitates the formation of final tempered martensite under serving conditions. In this study, we have gained deeper insights on the mechanism underlying the microstructural evolution during tempering treatment, including the precipitation of carbides and the coarsening of martensite laths, as systematically analyzed by optical microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. The chemical composition of the precipitates was analyzed using energy dispersive X-ray spectroscopy. Results indicate the formation of M3C (cementite) precipitates under normalized conditions. However, they tend to dissolve within a short time of tempering, owing to their low thermal stability. This phenomenon was substantiated by X-ray diffraction analysis. Besides, we could observe the precipitation of fine carbonitrides (MX) along the dislocations. The mechanism of carbon diffusion controlled growth of M23C6 can be expressed by the Zener's equation. The movement of Y-junctions was determined to be the fundamental mechanism underlying the martensite lath coarsening process. Vickers hardness was estimated to determine their mechanical properties. Based on the comprehensive analysis of both the micro-structural evolution and hardness variation, the process of tempering can be separated into three steps.

  14. Effect of tempering temperature on the toughness of 9Cr–3W–3Co martensitic heat resistant steel

    International Nuclear Information System (INIS)

    Highlights: • Toughness of 9Cr–3W–3Co steel increases with increasing tempering temperature. • Toughness is influenced by hardness of base metal and length of crack propagation path. • Hardness of base metal is influenced by dislocation density and degree of supersaturation of the interstitial atoms. • Length of crack propagation path is influenced by length of the large angle boundaries. - Abstract: Effect of tempering temperature on the toughness of 9Cr–3W–3Co martensitic heat resistant steel was studied on the basis of the microstructures after normalized at 1100 °C for 1 h and then tempered at 740–780 °C for 3 h. With increasing tempering temperature from 740 °C to 780 °C, the absorbed energy of the 9Cr–3W–3Co steel increased greatly from 26 J to 115 J. The change of the toughness with increasing tempering temperature was attributed to the softening of the base metal and the increase of the crack propagation path. The softening of the base metal was caused by the decrease of the dislocation density and the supersaturation of the interstitial atoms. The reason for the increase of the crack propagation path was that the length of the large angle boundaries increased and then the propagation direction of the cleavage crack was deflected more frequently

  15. Modifying effect of extremal temperature depending on the organism adaptation to this factor on the effect of radiation. 2. Analysis of the potential damages using heat resistance

    International Nuclear Information System (INIS)

    It is shown, that the effect of high temperature within the range of 33, 35, 37 and 38 deg C after irradiation (X-rays 3000r) increases the radiation effect, manifesting itself in the loss of X-chromosome of Kanton-C line flies, not adapted to high temperature. It takes place at the expense of reparation process depression and the increase of probability of potential damage realization. The effect on the flies of T-32 line, adapted to high temperature (32 deg C) turned non-effective at the temperature of 33 and 35 deg C. Heat-resistance of reparation ferments in this line is supposed to be higher. The temperature of 37 and 38 deg C has been effective for heat-resistant lines as well as for other lines

  16. Porous membrane with high curvature, three-dimensional heat-resistance skeleton: a new and practical separator candidate for high safety lithium ion battery

    OpenAIRE

    Shi, Junli; Xia, Yonggao; Yuan, Zhizhang; Hu, Huasheng; Li, Xianfeng; Zhang, Huamin; Liu, Zhaoping

    2015-01-01

    Separators with high reliability and security are in urgent demand for the advancement of high performance lithium ion batteries. Here, we present a new and practical porous membrane with three-dimension (3D) heat-resistant skeleton and high curvature pore structure as a promising separator candidate to facilitate advances in battery safety and performances beyond those obtained from the conventional separators. The unique material properties combining with the well-developed structural chara...

  17. Seasonal influence on heat-resistant proteolytic capacity of Pseudomonas lundensis and Pseudomonas fragi, predominant milk spoilers isolated from Belgian raw milk samples.

    Science.gov (United States)

    Marchand, Sophie; Heylen, Kim; Messens, Winy; Coudijzer, Katleen; De Vos, Paul; Dewettinck, Koen; Herman, Lieve; De Block, Jan; Heyndrickx, Marc

    2009-02-01

    Psychrotolerant bacteria and their heat-resistant proteases play a major role in the spoilage of UHT-processed dairy products. Summer and winter raw milk samples were screened for the presence of such bacteria. One hundred and three proteolytic psychrotolerant bacteria were isolated, characterized by API tests, rep-PCR fingerprint analysis and evaluated for heat-resistant protease production. Twenty-nine strains (representing 79% of the complete collection) were further identified by 16S rRNA gene sequencing, rpoB gene sequencing and DNA-DNA hybridizations. A seasonal inter- and intra-species influence on milk spoilage capacity (e.g. growth rate and/or protease production) was demonstrated. Moreover, this polyphasic approach led to the identification of Pseudomonas fragi and Pseudomonas lundensis (representing 53% of all isolates) as predominant producers of heat-resistant proteases in raw milk. The role of Pseudomonas fluorescens, historically reported as important milk spoiler, could not unequivocally be established. The use of more reliable identification techniques and further revision of the taxonomy of P. fluorescens will probably result in a different perspective on its role in the milk spoilage issue. PMID:19196277

  18. Development of heat resistant concrete and its application to concrete casks. Improvement of neutron shielding performance of concrete in high temperature environment

    International Nuclear Information System (INIS)

    Heat resistant concrete with hydrogen, which is able to shield neutron at more than 100degC, was developed. Using this new type concrete, a safety concrete cask having the same concept of metal casks was designed and produced. The new type cask omitted the inhalation and exhaust vent of the conventional type concrete casks. The new concrete consists of Portland cement added calcium hydroxide, iron powder and iron fiber. It showed 2.17 g/cm3 density, 10.8 mass% water content, 1.4 W/(m·K) thermal conductivity at 150degC. Increasing of heat resistance made possible to produce the perfect sealing type structure, which had high shielding performance of radiation no consideration for streaming of radiation. Moreover, a monitor of sealing can be set. General view of concrete casks, outer view of 1/3 scaled model, cask storage system in the world, properties of new developed heat resistant concrete, results of shielding calculation are contained. (S.Y.)

  19. Ocorrência de fungos filamentosos termo-resistentes em polpa de tomate envasada assepticamente / Occurrence of heat resistant molds in tomato pulp packed aseptically

    Scientific Electronic Library Online (English)

    Flávio, BAGLIONI; Homero Ferracini, GUMERATO; Pilar Rodriguez, MASSAGUER.

    1999-05-01

    Full Text Available Este trabalho teve como objetivo principal determinar a ocorrência de fungos filamentosos termo-resistentes durante o processamento asséptico de polpa de tomate (8° BRIX). Durante o período de safra de tomate foram feitas amostragens em 9 lotes (3 no início, 3 no pico e 3 em fim de safra) e no perío [...] do de entresafra em 5 lotes. Foi feita a enumeração de fungos termo-resistentes nas amostras coletadas durante as diferentes etapas do processo asséptico de cada lote. Foram obtidas contagens médias relativamente baixas, variando entre Abstract in english This work aimed at determining the occurrence of heat resistant molds during the aseptic processing of tomato pulp (8° BRIX). During tomato harvest, 9 lots were sampled (3 at the beginning, 3 at the apex and 3 at the end of harvest) and other 5 lots were sampled between harvest. For each lot, the en [...] umeration of heat resistant molds was carried out in samples collected during the aseptic process. The mean count of heat resistant molds was relatively low, ranging from

  20. Modeling the combined effects of pH, temperature and ascorbic acid concentration on the heat resistance of Alicyclobacillus acidoterrestis.

    Science.gov (United States)

    Bahçeci, K Sava?; Acar, Jale

    2007-12-15

    In this study, thermal inactivation parameters (D- and z-values) of Alicyclobacillus acidoterrestris spores in McIlvaine buffers at different pH, apple juice and apple nectar produced with and without ascorbic acid addition were determined. The effects of pH, temperature and ascorbic acid concentration on D-values of A. acidoterrestris spores were also investigated using response surface methodology. A second order polynomial equation was used to describe the relationship between pH, temperature, ascorbic acid concentration and the D-values of A. acidoterrestris spores. Temperature was the most important factor on D-values, and its effect was three times higher than those of pH. Although the statistically significant, heat resistance of A. acidoterrestris spores was not so influenced from the ascorbic acid within the concentration studied. D-values in apple juice and apple nectars were higher than those in buffers as heating medium at similar pH. The D-values ranged from 11.1 (90 degrees C) to 0.7 min (100 degrees C) in apple juice, 14.1 (90 degrees C) to 1.0 min (100 degrees C) in apple nectar produced with ascorbic acid addition, and 14.4 (90 degrees C) to 1.2 min (100 degrees C) in apple nectar produced without ascorbic acid addition. However, no significant difference in z-values was observed among spores in the juices and buffers at different pH, and it was between 8.2 and 9.2 degrees C. The results indicated that the spores of A. acidoterrestris may survive in fruit juices and nectars after pasteurization treatment commonly applied in the food industry. PMID:17936391

  1. Effect of yttrium on the cyclic oxidation behaviour of HP40 heat-resistant steel at 1373 K

    International Nuclear Information System (INIS)

    Research highlights: ? Yttrium has a benefit effect on the cyclic oxidation resistance of HP40 alloy. ? Y facilitates the formation of internal oxide (silica) during cyclic oxidation. ? A continuous spinel layer is observed on Y doped alloy during cyclic oxidation. ? The internal oxide (silica) improves the adherence of the scale. - Abstract: The effect of rare earth elements on cyclic oxidation behaviour of HP40 at 1373 K has been investigated. The results demonstrate that 0.06 wt.% addition of Y effectively improves the cyclic oxidation resistance of such Si-containing alloy. By observing the cross-section of the scale, it is found that Y facilitates the formation of Si-rich internal oxide, which improves the spalling resistance of the scale. As a result, compared with the sample without Y addition, on which the spinel layer is discontinuous, a continuous duplex scale of chromia overlaid by manganese-rich spinel is kept at the outmost of the Y-modified alloy.

  2. 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

  3. Study of nucleation, growth and coarsening of precipitates in a novel 9%Cr heat resistant steel: Experimental and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Prat, O., E-mail: oprat@udec.cl [Universidad de Concepción, Departamento de Ingeniería de Materiales, Edmundo Larenas 270, Concepción (Chile); García, J. [AB Sandvik Coromant R and D, Lerkrogsvägen 19, 12680 Stockholm (Sweden); Rojas, D.; Sanhueza, J.P.; Camurri, C. [Universidad de Concepción, Departamento de Ingeniería de Materiales, Edmundo Larenas 270, Concepción (Chile)

    2014-01-15

    Nucleation, growth and coarsening of three different precipitates (NbC, M{sub 23}C{sub 6} and V(C,N)) in a novel 9%Cr heat resistant steel designed by the authors were investigated. The microstructure evolution after tempering (780 °C/2 h) and after creep (650 °C/100 MPa) was characterized using transmission electron microscopy in the scanning mode (STEM). Thermodynamic and kinetic modeling was carried out using the softwares Thermo-Calc, DICTRA and TC-PRISMA. The Thermo-Calc software predicted formation of NbC, V(C,N) and M{sub 23}C{sub 6} carbides at the tempering temperature of 780 °C. STEM investigations revealed that M{sub 23}C{sub 6} precipitated on prior austenite grain boundaries and lath or block boundaries whereas NbC and V(C,N) were located within sub-grains. Simulations by TC-PRISMA showed that M{sub 23}C{sub 6}, NbC and V(C,N) particles nucleation begins as soon as the tempering treatment starts and it is completed in a very short time, reaching the equilibrium volume fraction after 40 s for M{sub 23}C{sub 6}, 100 s for NbC and 80 s for V(C,N). Best agreement between simulations and experimental investigations was found for low interfacial energy values of 0.1 J m{sup ?2}. Both STEM measurements as well as DICTRA simulations indicate very low coarsening rate for both kind of precipitates. Creep tests up to 4000–5000 h suggest that this special combination of NbC, V(C,N) and M{sub 23}C{sub 6} may provide increased pinning of dislocations reducing boundary migration therefore enhancing creep strength. - Highlights: • Nucleation, growth and coarsening of NbC and M{sub 23}C{sub 6} precipitates were investigated. • The microstructure was characterized using transmission electron microscopy (STEM). • Modeling was carried out using the softwares Thermo-Calc, DICTRA and TC-PRISMA. • M{sub 23}C{sub 6} and NbC nucleation begins as soon as the solution treatmentinitiates. • Best agreement modeling/experiments was found for low interfacial energy values of 0.1 J m{sup ?2}.

  4. Cast heat-resistant austenitic steel with improved temperature creep properties and balanced alloying element additions and methodology for development of the same

    Science.gov (United States)

    Pankiw, Roman I; Muralidharan, Govindrarajan; Sikka, Vinod Kumar; Maziasz, Philip J

    2012-11-27

    The present invention addresses the need for new austenitic steel compositions with higher creep strength and higher upper temperatures. The new austenitic steel compositions retain desirable phases, such as austenite, M.sub.23C.sub.6, and MC in its microstructure to higher temperatures. The present invention also discloses a methodology for the development of new austenitic steel compositions with higher creep strength and higher upper temperatures.

  5. Effect of glass-ceramic-processing cycle on the metallurgical properties of candidate alloys for actuator housings

    Energy Technology Data Exchange (ETDEWEB)

    Weirick, L.J.

    1982-01-01

    This report summarizes the results from an investigation on the effect of a glass ceramic processing cycle on the metallurgical properties of metal candidates for actuator housings. The cycle consists of a 980/sup 0/C sealing step, a 650/sup 0/C crystallization step and a 475/sup 0/C annealing step. These temperatue excursions are within the same temperature regime as annealing and heat treating processes normally employed for metals. Therefore, the effect of the processing cycle on metallurgical properties of microstructure, strength, hardness and ductility were examined. It was found that metal candidates which are single phase or solid solution alloys (such as 21-6-9, Hastelloy C-276 and Inconel 625) were not affected whereas multiphase or precipitation hardened alloys (such as Inconel 718 and Titanium ..beta..-C) were changed by the processing cycle for the glass ceramic.

  6. 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 ?atm H2, 450 ?atm CO, 50 ?atm CH4 and 50 ?atm H2O for Environment A; 200 ?atm H2, 100 ?atm CO, 20 ?atm CH4, 50 ?atm H2O and 5 ?atm CO2 for Environment B; 500 ?atm H2, 50 ?atm CO, 50 ?atm CH4 and 2O for Environment C; and 500 ?atm H2, 50 ?atm CO, 50 ?atm CH4 and 1.5 ?atm 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

  7. Padrão eletroforético de proteínas resistentes ao calor em sementes de milho Electrophorectic pattern of the heat resistant proteins of corn seeds

    Directory of Open Access Journals (Sweden)

    Solange Carvalho Barrios Roveri José

    2005-02-01

    Full Text Available Na aquisição e manutenção da tolerância à dessecação de sementes, há vários mecanismos envolvidos, entre eles a indução das proteínas resistentes ao calor. O objetivo deste trabalho foi avaliar mudanças no padrão eletroforético das proteínas resistentes ao calor de sementes de milho submetidas a alta temperatura de secagem, associando-as à sua tolerância. Foram utilizadas sementes de linhagens, híbridos simples e híbridos recíprocos colhidas com teor de água de aproximadamente 35% e secadas a 45°C. Sementes das linhagens secadas à sombra foram utilizadas como controle e sua qualidade fisiológica foi avaliada por meio do teste de germinação. As proteínas resistentes ao calor foram extraídas de eixos embrionários das sementes em tampão Tris HCl 0,05 M. Não foi possível determinar uma banda específica da fração das proteínas resistentes ao calor que possa servir como marcador da tolerância à alta temperatura de secagem. Houve estabilidade nos padrões de bandas das proteínas provenientes de sementes submetidas à secagem artificial e natural, mesmo quando foram observadas variações nos valores de germinação. Os padrões eletroforéticos das proteínas resistentes ao calor foram semelhantes entre as sementes híbridas e os respectivos recíprocos.Several mechanisms are involved in the acquisition and maintenance of desiccation tolerance by the seeds. One of these mechanisms is related to the induction of heat resitant proteins. The objective of this work was to evaluate changes in the electophorectic patterns of the heat resistant proteins of corn seeds submitted to high drying temperature associating their expression with drying tolerance. Seeds of breeding lines, simple hybrids and respective reciprocals hybrids were utilized. The seeds were harvested with approximately 35% of water content and dried at 45°C. Seeds of lines dried under shadow were used as control and the physiological quality was evaluated by germination test. The heat resistant proteins were extracted from embryonic axis of seeds in Tris-HCl 0.05 M buffer. It was not possible to determine a specific band of heat resistant proteins which can be of use as a molecular marker of tolerance to high drying temperature. There was stability in the patterns of the bands of proteins of seeds submitted to artificial drying compared to the ones after shadow drying even for the lines of high variation in the germination values. The electrophorectic patterns of the heat resistant proteins were similar for both the hybrid seeds and respective reciprocals.

  8. The reactive-element effect in the high-temperature oxidation of Fe-23Cr-5Al commercial alloys

    International Nuclear Information System (INIS)

    The effect of yttrium and hafnium additions on high-temperature oxidation resistance of modified Fe-23Cr-5Al commercial, heat-resistant alloys was studied. The oxidation resistance was evaluated by the used of accelerated-life tests and isothermal oxidation for wires and flat samples, respectively. A sol-gel method of modification of the surface properties of ready-made heating elements was examined. The effect of several sol-gel coatings on the alloy oxidation behavior in the accelerated-life test was studied

  9. Fatigue properties of nickel-base high temperature alloys for HTGRs

    International Nuclear Information System (INIS)

    A series of strain controlled low-cycle fatigue tests were conducted at temperatures ranging from room temperature (RT) to 900 deg. C on nickel-base high-temperature alloys, namely Hastelloy X and its modified versions Hastelloy XR and Hastelloy XR-II, which are candidate alloys for HTGR applications. The tests were conducted in the simulated HTGR helium environment with the exception of those conducted in air at RT. In those tests the examination was made on the effects of strain rate, hold time, aging and test temperature on fatigue properties. Decreasing the strain rate led to notable decreases in the fatigue life. Based on the stress-strain curves and the crack morphology, it was suggested that a considerable contribution of creep damage was included at lower strain rates. In the experiments with the trapezoidal strain waveform with different holding types, the fatigue life was found to be reduced most effectively in tensile hold-time experiments. From the observations of the crack morphology the strain holding in the compressive side was suggested to play the role of suppressing the initiation and the growth of internal cracks and/or cavities, and to cause crack branching. The fatigue lives of the aged (900 deg. C, 1000h) specimens were shorter than those of the solution annealed ones at test temperatures ranging from RT to 700 deg. C. The tendency became more pronounced under higher strain range conditions. The reduction in the fatigue life due to aging treatment, observed through the tests conducted at and below 700 deg. C, was closely related with the loss of tensile ductility, which was attributed to the precipitation of M6C carbide along the grain boundaries which occurred during the aging. Fractographic features and crack morphology of the aged specimens fatigued at and below 700 deg. C were of brittle nature relative to those of the solution annealed ones fatigued in the same temperature range. The fatigue lives estimated from the tensile properties using the method proposed by Manson were consistent with the results of fatigue tests under the test conditions employed. (author). 16 refs, 25 figs, 3 tabs

  10. 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)

  11. Investigation of the structure and properties of the titanium alloy of the Ti-Al-Mo-V-Fe-Cu-Zr-Sn system

    International Nuclear Information System (INIS)

    The alloys of martensitic type in the Ti-Al-Mo-V-Fe-Cu-Zr-Sn system after heat treatment are investigated. To determine the composition of the titanium alloy methods of mathematical planning of the experiment are applied. Results of mechanical tests of the alloys are presented, as well as coefficients of models for the properties, calculated according to these data. The investigation establishes the composition of a high-strength titanium alloy of a martensitic type, containing 4.5-60 % Al, 2.0-4.0 % Mo, 0.5-1.9 % V, 0.3-1.5 % Fe, 0.3-1.5 % Cu, 1.5-3.0 % Sn, 2.0-4.0 % Zr. The semiproducts, produced by deformation in ?-field, after heat treatment have an ultimate strength >=120 kg/mm2, satisfactory ductility and reliability. The alloy possesses rather a high heat resistance and can be operated at 400-500 deg C

  12. Corrosion protection of 13CrMo 44 heat-resistant ferritic steel by silicon and cerium ion implantation for high-temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Perez, F.J.; Otero, E.; Hierro, M.P.; Gomez, C.; Pedraza, F. [Universidad Complutense de Madrid (Spain). Dept. de Ciencia de los Materiales; Segovia, J.L. de [Consejo Superior de Investigaciones Cientificas, Inst. Torres Quevedo, Madrid (Spain); Roman, E. [Consejo Superior de Investigaciones Cientificas, Inst. de Ciencia de los Materiales, Canto Blanco, Madrid (Spain)

    1998-10-10

    The influence of the ion implantation of 1 x 10{sup 15} ions/cm{sup 2} of silicon and 1 x 10{sup 14} ions/cm{sup 2} of cerium at 150 keV on the oxidation behaviour of a 0.80%Cr-0.40%Mo heat-resistant 13CrMo 44 ferritic steel was studied at 973 K in air for 144 h under isothermal conditions. The implanted surfaces and the corrosion products formed on the surface were characterized by means of AES, SEM and XRD. Theoretical calculations were performed by TRIM96 computational code. From the present study it was concluded that silicon enhances selective oxidation of chromium and a more protective oxide scale was found to grow. However, cerium confers a detrimental effect by cracking and spalling of the oxide layers formed at high temperature. (orig.) 13 refs.

  13. Vaulted trans-bis(salicylaldiminato)platinum(II) crystals: heat-resistant, chromatically sensitive platforms for solid-state phosphorescence at ambient temperature.

    Science.gov (United States)

    Komiya, Naruyoshi; Okada, Minoru; Fukumoto, Kanako; Kaneta, Kenji; Yoshida, Atsushi; Naota, Takeshi

    2013-04-01

    The synthesis, structure, and solid-state emission of vaulted trans-bis(salicylaldiminato)platinum(II) complexes are described. A series of polymethylene (1: n=8; 2: n=9; 3: n=10; 4: n=11; 5: n=12; 6: n=13) and polyoxyethylene (7: m=2; 8: m=3; 9: m=4) vaulted complexes (R=H (a), 3-MeO (b), 4-MeO (c), 5-MeO (d), 6-MeO (e), 4-CF3O (f), 5-CF3O (g)) was prepared by treating [PtCl2(CH3CN)2] with the corresponding N,N'-bis(salicylidene)-1,?-alkanediamines. The trans coordination, vaulted structures, and the crystal packing of 1-9 have been unequivocally established from X-ray diffraction studies. Unpredictable, structure-dependent phosphorescent emission has been observed for crystals of the complexes under UV excitation at ambient temperature, whereas these complexes are entirely nonemissive in the solution state under the same conditions. The long-linked complex crystals 4-6, 8, and 9 exhibit intense emission (?77K =0.22-0.88) at 77 K, whereas short-linked complexes 1-3 and 7 are non- or slightly emissive at the same temperature (?77K heat resistance towards emission decay with increasing temperature (?298K =0.21-0.38). Chromogenic control of solid-state emission over the range of 98 nm can be performed simply by introducing MeO groups at different positions on the aromatic rings. Orange, yellow-green, red, and yellow emissions are observed in the glass and crystalline state upon 3-, 4-, 5-, and 6-MeO substitution, respectively, whereas those with CF3 O substituents have orange emission, irrespective of the substitution position. DFT calculations (B3LYP/6-31G*, LanL2DZ) showed that such chromatic variation is ascribed to the position-specific influence of the substituents on the highest-occupied molecular orbital (HOMO) and lowest-unoccupied molecular orbital (LUMO) levels of the trans-bis(salicylaldiminato)platinum(II) platform. The solid-state emission and its heat resistance have been discussed on the basis of X-ray diffraction studies. The planarity of the trans-coordination sites is strongly correlated to the solid-state emission intensities of crystals 1-9 at lower temperatures. The specific heat-resistance properties shown exclusively by the 5a, 6a, 9a, and 9d crystals are due to their strong three-dimensional hydrogen-bonding interactions and/or Pt···Pt contacts, whereas heat-quenchable crystals 4a, 4b, 5c, 5e, 6c, 6e, and 9b are poorly bound with limited interactions, such as non-, one-, or two-dimensional hydrogen-bonding networks. These results lead to the conclusion that Pt···Pt contacts are an important factor in the heat resistance of solid-state phosphorescence at ambient temperature, although the role of Pt···Pt contacts can be substituted by only higher-ordered hydrogen-bonding fixation. PMID:23418050

  14. Effect of sporulation medium on wet-heat resistance and structure of Alicyclobacillus acidoterrestris DSM 3922-type strain spores and modeling of the inactivation kinetics in apple juice.

    Science.gov (United States)

    Molva, Celenk; Baysal, Ayse Handan

    2014-10-17

    Alicyclobacillus acidoterrestris is a spoilage bacterium in fruit juices leading to high economic losses. The present study evaluated the effect of sporulation medium on the thermal inactivation kinetics of A. acidoterrestris DSM 3922 spores in apple juice (pH3.82±0.01; 11.3±0.1 °Brix). Bacillus acidocaldarius agar (BAA), Bacillus acidoterrestris agar (BATA), malt extract agar (MEA), potato dextrose agar (PDA) and B. acidoterrestris broth (BATB) were used for sporulation. Inactivation kinetic parameters at 85, 87.5 and 90°C were obtained using the log-linear model. The decimal reduction times at 85°C (D85°C) were 41.7, 57.6, 76.8, 76.8 and 67.2min; D87.5°C-values were 22.4, 26.7, 32.9, 31.5, and 32.9min; and D90°C-values were 11.6, 9.9, 14.7, 11.9 and 14.1min for spores produced on PDA, MEA, BATA, BAA and BATB, respectively. The estimated z-values were 9.05, 6.60, 6.96, 6.15, and 7.46, respectively. The present study suggests that the sporulation medium affects the wet-heat resistance of A. acidoterrestris DSM 3922 spores. Also, the dipicolinic acid content (DPA) was found highest in heat resistant spores formed on mineral containing media. After wet-heat treatment, loss of internal volume due to the release of DPA from spore core was observed by scanning electron microscopy. Since, there is no standardized media for the sporulation of A. acidoterrestris, the results obtained from this study might be useful to determine and compare the thermal resistance characteristics of A. acidoterrestris spores in fruit juices. PMID:25129530

  15. Metal dusting behaviour of furnace tube alloys

    Directory of Open Access Journals (Sweden)

    Abdulaziz Al-Meshari

    2009-10-01

    Full Text Available Metal dusting has long been a chronic problem for several industrial sectors. In order to obtain a better understanding of the aspects of this failure mode, three heat-resistant alloys, KHR35C HiSi©, KHR45A LC©, and UCX© were exposed to a gas mixture of 80 vol% CO+20 vol% H2 flowing at 100cm3 min-1 at 650, 750, and 850ºC for 100h. The alloys were then characterised by visual examination, XRD, and SEM/EDX. In conclusion, KHR35C HiSi© suffered localised metal dusting at 650 and 750ºC and the attack became less aggressive with the temperature increase. The least attack on KHR35C HiSi© was however observed after exposure at 850ºC. The corrosion mode at each temperature was also elucidated. Pitting also occurred on KHR45A LC© after exposure at 650ºC but to a lesser degree compared to KHR35C HiSi©. Moreover, a few pits were observed on KHR45A LC© exposed at 750ºC with the least took place at 850ºC. UCX©, which contained the highest concentrations of chromium and nickel, exhibited the best resistance to metal dusting at the test temperatures.

  16. Development of cladding materials composed of alloys with high compatibility to each corrosive environment on pressure boundaries in nuclear plants

    Energy Technology Data Exchange (ETDEWEB)

    Kiuchi, Kiyoshi; Kikuchi, Masahiko; Ide, Hisayuki; Takagi, Yoshio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-03-01

    Pressure boundary materials used in severe corrosive nuclear environments were developed by means of new alloy designs for attaining the sufficient thermodynamical stability against both heavy irradiations and chemical attacks. Type F5 stainless steel with high austenite phase stability and nickel base silicide dispersed alloy so-called the HWI alloy with the high wear corrosion resistance were developed for core materials in water cooling type nuclear reactors. Three kind of alloys, namely, type 304ULC(EB-SAR), nickel base Cr-W-Si alloy so-called the RW alloy and niobium base alloys which have each different oxidation potential region on these application were developed for vessel materials used in nitric acid environments on reprocessing plants of spent nuclear fuels. The corrosion resistance and the workability of these alloys were improved markedly by means of the electron beam melting for removing harmful impurities in alloy matrixes and the thermomechanical treatment so-called SAR for modifying micro-structures. For improving all-round properties required for pressure boundary materials, cladding technologies between corrosion resistant materials and heat resistant materials were developed by means of diffusion bonding and hydro-isostatic pressing. These cladding process were optimized by both experimentally and theoretically. (author)

  17. Effects of spherical quasi-crystal on microstructure and mechanical properties of ZA155 high zinc magnesium alloy

    Directory of Open Access Journals (Sweden)

    Zhang Jinshan

    2010-05-01

    Full Text Available Effects of spherical quasi-crystal contained in Mg-Zn-Y-Mn master alloy on the microstructure and as-cast mechanical properties of ZA155 high zinc magnesium alloy have been investigated by means of optical microscopy, XRD, SEM, EDS, tensile test, impact test and hardness test. Experimental results show that the addition of spherical quasi-crystal contained in the Mg-Zn-Y-Mn master alloy into the ZA155 high zinc magnesium alloy resulted in grain refinement of the matrix, changing the morphologies of ?-Al2Mg5Zn2 phase and ?-Mg32(Al, Zn49 phase from continuous net-like structures to discontinuous strip-like structure and blocky one, respectively. In the present research, the best comprehensive mechanical properties of reinforced ZA155 high zinc magnesium alloy has been obtained when 5.0wt% spherical quasi-crystal was introduced from the Mg-Zn-Y-Mn master alloy into the target alloy system. In such case, the room-temperature tensile strength reached 207 MPa, about 23% higher than that of the base alloy; the impact toughness peaked at 5.5 J/cm2, about 40% higher than that of the base alloy; and the elevated-temperature tensile strength reached 203 MPa, indicating improved heat resistance.

  18. The effect of Ca addition on microstructures and mechanical properties of Mg-RE based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jin-shan, E-mail: jinshansx@tom.com [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Sun, Yan; Cheng, Wei-li; Que, Zhong-ping; Li, Yong-mei [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Liushan, Liangzi [School of Material Science and Engineering, Lanzhou University of Technology, Lanzhou 730050 (China)

    2013-03-25

    Highlights: ? Calcium can be used to refine ?-Mg grains in the Mg-RE based magnesium alloy. ? Calcium causes some thermally stable intermetallic compound phases. ? Those stable phases can effectively improve the mechanical property. ? Unknown four elementary phases are formed at the grain boundary. -- Abstract: AM-SC1 (Advanced Magnesium-Sand Casting Alloy 1) is a heat-resisting Mg-RE based alloy which has been widely applied in engine block. It would be an effective way to decrease the cost of the alloy by replacing Nd with Ca as addition. The effects of Ca addition on the microstructure and mechanical properties of the alloy were investigated by means of Brinell hardness measurement, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction and tensile tests at room and elevated temperatures. As the addition of Ca is 1.5%, the alloy shows the finest grain size of 16 ?m which also contributes to the highest hardness and strength of 62.1 HB and 148 MPa, respectively. After T6 treatment (solid solution treatment at 500 °C for 7 h and aging treatment at 200 °C for 20 h), the morphologies of the phases in the Ca-containing alloys change from net-like to fine short-block and particle-like shapes, and its strengths at RT, 175 °C and 200 °C are correspondingly improved to 186 MPa, 166 MPa and 140 MPa, respectively.

  19. Isolamento e seleção de fungos filamentosos termorresistentes em etapas do processo produtivo de néctar de maçã / Isolation and selection of heat resistant molds in the production process of apple nectar

    Scientific Electronic Library Online (English)

    Beatriz de Cássia Martins, Salomão; Pilar Rodriguez, Massaguer; Gláucia Maria Falcão, Aragão.

    2008-03-01

    Full Text Available Os fungos filamentosos termorresistentes são capazes de sobreviver aos processos de pasteurização aplicados aos produtos de frutas. Este estudo visou isolar e identificar fungos termorresistentes durante o processamento de néctar de maçã (pH 3,4 e 11,6 °Brix), de forma a selecionar o bolor mais term [...] orresistente. O isolamento foi obtido após choque térmico de 70 °C/2 horas e incubação a 30 °C em PDA (3% de ágar) acrescido de rosa de bengala. A identificação foi baseada na morfologia e nas estruturas micro e macroscópicas observadas após incubação das cepas em três diferentes meios (G25N, CYA e MEA) e temperaturas. O fungo mais termorresistente foi selecionado pela aplicação de choques térmicos (de 80 °C/20 minutos até 97 °C/15 minutos). Foram detectadas 11 linhagens de bolores, sendo 5 termorresistentes. Dentre estas, três cepas, isoladas da matéria-prima e do concentrado de maçã, foram identificadas como Neosartorya fischeri; uma cepa isolada da matéria-prima foi identificada como Byssochlamys fulva, e uma cepa isolada do produto após a primeira pasteurização foi identificada como Eupenicillium sp. As cepas mais resistentes foram as de N. fischeri e B. fulva, que sobreviveram ao tratamento de 95 °C/20 minutos. Dentre as seis cepas restantes, uma foi identificada como Aspergillus sp., entretanto, nenhuma destas apresentou termorresistência. Abstract in english Heat resistant molds are able to survive the pasteurization process applied to apple products. This study aimed at detecting and identifying heat resistant molds during the processing of apple nectar (pH 3.4; 11.6 °Brix) in order to select the most heat resistant mold. The isolation was carried out [...] after heat shock at 70 °C, during 2 hours, and incubation at 30 °C, in PDA (3% agar), where rose bengal was added. The identification of macro and microscopic structures was carried out after incubation in three different media (G25N, CYA, MEA) and temperatures. Different heat shocks, from 80 °C/20 minutes to 97 °C/15 minutes, were applied to select the most heat resistant mold. Eleven strains were selected, of which five were heat-resistant: three strains were isolated from apple and concentrated apple juice and were identified as Neosartorya fischeri; one strain, isolated from apple, was identified as Byssochlamys fulva and one strain, isolated from the product after the first pasteurization, was identified as Eupenicillium sp. The most heat-resistant strains belong to N. fischeri and B. fulva, which were able to survive at 95 °C/20 minutes. Among the six remaining, one was identified as Aspergillus sp., however, none of them was heat resistant.

  20. Chemical analysis of nickel- and iron-base high-temperature alloys for nuclear reactor

    International Nuclear Information System (INIS)

    The Committee studied problems in analysis of alloys used for High-Temperature Gas Cooled Reactor from September 1970 to February 1976. The alloys selected from the standpoint of analytical chemistry are Inconel 600, Incoloy 800, Inconel X750, Inco 713C and Hastelloy X. Nine standard samples (JAERI-R 1 to JAERI-R 9) of the high-temperature alloys were prepared primarily for X-ray fluorescence method. Eighteen research institutions in Japan participated in cooperative analyses of the standard samples for 19 elements (C, Si, Mn, P, S, Ni, Cr, Fe, Mo, Cu, W, V, Co, Ti, Al, B, Nb, Ta, Zr). Prior to analyses of the standard samples, 8 cooperative samples (A-H) were analyzed to develop and evaluate analytical methods. Described in this report are preparation and their characteristics of the standard samples, results of analyses, and 93 analytical methods. The results of the cooperative experiments on atomic absorption spectrophotometry and X-ray fluorescence method are also described. (auth.)

  1. Technology readiness level (TRL) assessment of cladding alloys for advanced nuclear fuels

    International Nuclear Information System (INIS)

    Reliable fuel claddings are essential for the safe, sustainable and economic operation of nuclear stations. This paper presents a worldwide TRL assessment of advanced claddings for Gen III and IV reactors following an extensive literature review. Claddings include austenitic, ferritic/martensitic (F/M), reduced activation (RA) and oxide dispersion strengthened (ODS) steels as well as advanced iron-based alloys (Kanthal alloys). Also assessed are alloys of zirconium, nickel (including HastelloyR), titanium, chromium, vanadium and refractory metals (Nb, Mo, Ta and W). Comparison is made with Cf/C and SiCf/SiC composites, MAX phase ceramics, cermets and TRISO fuel particle coatings. The results show in general that the higher the maximum operating temperature of the cladding, the lower the TRL. Advanced claddings were found to have lower TRLs than the corresponding fuel materials, and therefore may be the limiting factor in the deployment of advanced fuels and even possibly the entire reactor in the case of Gen IV. (authors)

  2. Siegel FIRST EXPERIMENTAL DISCOVERY of Granular-Giant-Magnetoresistance (G-GMR) DiagnosES/ED Wigner's-Disease/.../Spinodal-Decomposition in ``Super''Alloys Generic Endemic Extant in: Nuclear-Reactors/ Petrochemical-Plants/Jet/ Missile-Engines/...

    Science.gov (United States)

    Hoffman, Ace; Wigner-Weinberg, Eugene-Alvin; Siegel, Edward Carl-Ludwig Sidney; ORNL/Wigner/Weinberg/Siegel/Hollifeld/Yu/... Collaboration; ANL/Fermi/Wigner/Arrott/Weeks/Bader/Freeman/Sinha/Palazlotti/Nichols/Petersen/Rosner/Zimmer/... Collaboration; BNL/Chudahri/Damask/Dienes/Emery/Goldberg/Bak//Bari/Lofaro/... Collaboration; LLNL-LANL/Hecker/Tatro/Meara/Isbell/Wilkins/YFreund/Yudof/Dynes/Yang/... Collaboration; WestinKLouse/EPRI/PSEG/IAEA/ABB/Rickover/Nine/Carter/Starr/Stern/Hamilton/Richards/Lawes/OGrady/Izzo Collaboration

    2013-03-01

    Siegel[APS Shock-Physics Mtg., Chicago(11)] carbides solid-state chemistry[PSS (a)11,45(72); Semis. & Insuls. 5: 39,47,62 (79)], following: Weinberg-Siegel-Loretto-Hargraves-Savage-Westwood-Seitz-Overhauser-..., FIRST EXPERIMENTAL DISCOVERY of G-GMR[JMMM 7, 312(78); Google: ``If LEAKS Could KILL Ana Mayo''] identifIED/IES GENERIC ENDEMIC EXTANT domination of old/new (so mis-called) ``super''alloys': nuclear-reactors/spent-fuel-casks/refineries/jet/missile/rocket-engines in austenitic/FCC Ni/Fe/Co-based (so mis-called) ''super''alloys (182/82; Hastelloy-X,600,304/304L-Stainless-Steels,...,690!!!) GENERIC ENDEMIC EXTANT detrimental(synonyms!!!): THERMAL: Wigner's-disease(WD physics) [J.Appl.Phys.17,857(46)]/ Ostwald-ripening

  3. Heat resistance mediated by a new plasmid encoded Clp ATPase, ClpK, as a possible novel mechanism for nosocomial persistence of Klebsiella pneumoniae.

    DEFF Research Database (Denmark)

    Bojer, Martin Saxtorph; Struve, Carsten

    2010-01-01

    Klebsiella pneumoniae is an important opportunistic pathogen and a frequent cause of nosocomial infections. We havecharacterized a K. pneumoniae strain responsible for a series of critical infections in an intensive care unit over a two-year period. The strain was found to be remarkably thermotolerant providing a conceivable explanation of its persistence in the hospital environment. This marked phenotype is mediated by a novel type of Clp ATPase, designated ClpK. The clpK gene is encoded by a conjugative plasmid and we find that the clpK gene alone renders an otherwise sensitive E. coli strain resistant to lethal heat shock. Furthermore, one third of a collection of nosocomial K. pneumoniae isolates carry clpK and exhibit a heat resistant phenotype. The discovery of ClpK as a plasmid encoded factor and its profound impact on thermal stress survival sheds new light on the biological relevance of Clp ATPases in acquired environmental fitness and highlights the challenges of mobile genetic elements in fighting nosocomial infections

  4. Heat Resistance Mediated by a New Plasmid Encoded Clp ATPase, ClpK, as a Possible Novel Mechanism for Nosocomial Persistence of Klebsiella pneumoniae

    DEFF Research Database (Denmark)

    Bojer, Martin Saxtorph; Struve, Carsten

    2010-01-01

    Klebsiella pneumoniae is an important opportunistic pathogen and a frequent cause of nosocomial infections. We have characterized a K. pneumoniae strain responsible for a series of critical infections in an intensive care unit over a two-year period. The strain was found to be remarkably thermotolerant providing a conceivable explanation of its persistence in the hospital environment. This marked phenotype is mediated by a novel type of Clp ATPase, designated ClpK. The clpK gene is encoded by a conjugative plasmid and we find that the clpK gene alone renders an otherwise sensitive E. coli strain resistant to lethal heat shock. Furthermore, one third of a collection of nosocomial K. pneumoniae isolates carry clpK and exhibit a heat resistant phenotype. The discovery of ClpK as a plasmid encoded factor and its profound impact on thermal stress survival sheds new light on the biological relevance of Clp ATPases in acquired environmental fitness and highlights the challenges of mobile genetic elements in fightingnosocomial infections.

  5. XRD and TEM analysis of microstructure in the welding zone of 9Cr–1Mo–V–Nb heat-resisting steel

    Indian Academy of Sciences (India)

    Li Yajiang; Wang Juan; Zhou Bing; Feng Tao

    2002-06-01

    Under the condition of tungsten inert gas shielded welding (TIG) + shielded metal arc welding (SMAW) technology, the microstructure in the welding zone of 9Cr–1Mo–V–Nb (P91) heat-resisting steel is studied by means of X-ray diffractometry (XRD) and transmission electron microscopy (TEM). The test results indicate that when the weld heat input () of TIG is 8.5 ? 11.7 kJ/cm and the weld heat input of SMAW is 13.3 ? 21.0 kJ/cm, the microstructure in the weld metal is composed of austenite and a little amount of ferrite. The substructure of austenite is crypto–crystal martensite, which included angle. There are some spot precipitates in the martensite base. TEM analysis indicates that the fine structure in the heat-affected zone is lath martensite. There are some carbides (lattice constant, 1.064 nm) at the boundary of grain as well as inside the grain, most of which are Cr23C6 and a little amount of (Fe, Me)23C6.

  6. Creep strength and microstructural evolution of 9-12% Cr heat resistant steels during creep exposure at 600 C and 650 C

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Martin, Francisca [Graz Univ. of Technology (Austria). Inst. for Materials Science and Welding; Panait, Clara Gabriela [MINES ParisTech, UMR CNRS, Evry (France). Centre des Materiaux; V et M France CEV, Aulnoye-Aymeries (France); Bendick, Walter [Salzgitter Mannesmann Forschung GmbH (SZMF), Duisburg (DE)] (and others)

    2010-07-01

    9-12% Cr heat resistant steels are used for applications at high temperatures and pressures in steam power plants. 12% Cr steels show higher creep strength and higher corrosion resistance compared to 9% Cr steels for short term creep exposure. However, the higher creep strength of 12 %Cr steels drops increasingly after 10,000-20,000 h of creep. This is probably due to a microstructural instability such as the precipitation of new phases (e.g. Laves phases and Z-phases), the growth of the precipitates and the recovery of the matrix. 9% Cr and 12% Cr tempered martensitic steels that have been creep tested for times up to 50,000 h at 600 C and 650 C were investigated using Transmission Electron Microscopy (TEM) on extractive replicas and thin foils together with Backscatter Scanning Electron Microscopy (BSE-SEM) to better understand the different creep behaviour of the two different steels. A significant precipitation of Laves phase and low amounts of Z-phase was observed in the 9% Cr steels after long-term creep exposure. The size distribution of Laves phases was measured by image analysis of SEM-BSE images. In the 12% Cr steel two new phases were identified, Laves phase and Z-phase after almost 30,000 h of creep test. The quantification of the different precipitated phases was studied. (orig.)

  7. The evolution of precipitates of 22Cr-25Ni-Mo-Nb-N heat-resistant austenitic steel in long-term creep

    International Nuclear Information System (INIS)

    The microstructural evolution of 22Cr-25Ni-Mo-Nb-N heat-resistant steel after creep under different stresses at 973 K has been systematically investigated. It is found that during short time creep MX and M23C6 predominantly precipitate in the matrix. While with the increase in creep time, Cr3Ni2SiX and ? precipitate in the matrix. MX is the main strengthen precipitate in the matrix after long time creep. Due to a fast coarsening rate, M23C6 in the matrix has a little effect on strengthening the matrix. Comparing the MX and M23C6 in the crept sample with those in the aged sample, it could be found that the creep stress can promote the coarsening rate of MX and has hardly any effect on the coarsening of M23C6. The effect of stress on the coarsening of precipitates focuses on the diffusion of solution atoms. Under the condition of stress, the diffusion of Nb is accelerated, while that of C changes little.

  8. Effect of microstructural evolution on high-temperature strength of 9Cr–3W–3Co martensitic heat resistant steel under different aging conditions

    International Nuclear Information System (INIS)

    Evolution of microstructures and high-temperature strength at 650 °C of 9Cr–3W–3Co martensitic heat resistant steel after aging at 650 °C and 700 °C for different time durations have been experimentally investigated using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), field emission transmission electron microscopy (FETEM) and post-aged tensile tests. The results show that after aging at 650 °C, the high-temperature strength and the microstructures of 9Cr–3W–3Co steel keep almost stable with increasing aging time from 300 h to 3000 h. In comparison, after aging at 700 °C, there are obvious changes in the high-temperature strength and the microstructures. The strengthening mechanisms of the 9Cr–3W–3Co steel were also discussed and the athermal yield stresses were calculated. The change of the high-temperature strength is mainly affected by the evolution of dislocations and laths. The precipitates mainly act as obstacles against motion of dislocations and lath boundaries

  9. Tungsten alloys

    Energy Technology Data Exchange (ETDEWEB)

    Steer, C.; Betteridge, R.; Mattingley, N.J.; Tweed, J.H.; Hudson, B.

    1993-12-08

    An alloy of tungsten and depleted uranium in which the concentration by volume of the tungsten is at least approximately equal to that of the depleted uranium is produced by melting depleted uranium pieces around tungsten particles after mixing or by treating smaller tungsten particles with molten uranium under pressure. (Author).

  10. Some peculiarities of arc welding of heat pipes of the Kh28N48V5 cast alloy

    International Nuclear Information System (INIS)

    Use of argon-electric arc welding of radiation pipes made it possible to considerably improve the strength of the welding joint and provide uninterrupted operation of thermal furnaces at the Pervouralsk Novotrubny Works. The method was applied in welding U-pipes consisting of a heat-resistant alloy, Kh28N48B5, suitable for making new and for repairing spent pipes of this type. For the first layer - GSl and for the second layer - OZL-31, electrodes were used with reversed polarity d.c. under conditions involving preheating of the welding spot to 600-700 deg C

  11. Effect of Mg-Zn-Nd spherical quasi-crystals on microstructure and mechanical properties of ZK60 alloy

    Directory of Open Access Journals (Sweden)

    Zhang Jinshan

    2011-08-01

    Full Text Available To improve the strength, toughness, heat-resistance and deformability of magnesium alloy, the microstructure and mechanical properties of ZK60 alloy strengthened by Mg-Zn-Nd spherical quasi-crystal phase (I-phase particles were investigated. Mg40Zn55Nd5 (I-phase particles in addition to ?-Mg, MgZn phase and MgZn2 phases can be obtained in ZK60-based composites under normal casting condition by the addition of quasi-crystal containing Mg-Zn-Nd master alloy. The experimental results show that the introduction of Mg-Zn-Nd spherical quasi-crystal phase into ZK60 alloy makes a great contribution to the refinement of the matrix microstructures and the improvement of mechanical properties. While adding Mg-Zn-Nd spherical quasi-crystal master alloy of 4.0wt.%, the ultimate tensile strength and yield strength of ZK60-based composite at ambient temperature reach their peak values of 256.7 MPa and 150.4 MPa, which were about 17.8% and 24.1% higher respectively than those of the ZK60 alloy. The improved mechanical properties are mainly attributed to the pinning effect of the quasi-crystal particles (I-phase at the grain boundaries. This research results provide a new way for strengthening and toughening of magnesium alloys as well as a new application of Mg-based spherical quasi-crystals.

  12. The effect of pre-oxidation and the influence of deformation on the corrosion behaviour of two heat resistant steels in a sulphur-oxygen-carbon bearing environment

    International Nuclear Information System (INIS)

    The influence of pre-oxidation on the corrosion resistance of the austenitic steels AC 66 (Fe-32Ni-27Cr-0.07Ce) and alloy 800H (Fe-32Ni-20Cr) was studied in a sulphur-oxygen-carbon bearing atmospheric at 700oC. For AC 66 the corrosion resistance was significantly improved by preoxidation, whereas this effect was less marked for Alloy 800H. This can be explained by a much better adherence of the preformed oxide scale for AC 66. The corrosion resistance was shown to decrease by superimposed deformation which leads to deeply penetrating intergranular corrosion paths. (Author)

  13. Optimization of in vitro regeneration and Agrobacterium tumefaciens-mediated transformation with heat-resistant cDNA in Brassica oleracea subsp. italica cv. Green Marvel.

    Science.gov (United States)

    Ravanfar, Seyed Ali; Aziz, Maheran Abdul; Saud, Halimi Mohd; Abdullah, Janna Ong

    2015-11-01

    An efficient system for shoot regeneration and Agrobacterium tumefaciens-mediated transformation of Brassica oleracea cv. Green Marvel cultivar is described. This study focuses on developing shoot regeneration from hypocotyl explants of broccoli cv. Green Marvel using thidiazuron (TDZ), zeatin, and kinetin, the optimization of factors affecting Agrobacterium-mediated transformation of the hypocotyl explants with heat-resistant cDNA, followed by the confirmation of transgenicity of the regenerants. High shoot regeneration was observed in 0.05-0.1 mg dm(-3) TDZ. TDZ at 0.1 mg dm(-3) produced among the highest percentage of shoot regeneration (96.67 %) and mean number of shoot formation (6.17). The highest percentage (13.33 %) and mean number (0.17) of putative transformant production were on hypocotyl explants subjected to preculture on shoot regeneration medium (SRM) with 200 µM acetosyringone. On optimization of bacterial density and inoculation time, the highest percentage and mean number of putative transformant production were on hypocotyl explants inoculated with a bacterial dilution of 1:5 for 30 min. Polymerase chain reaction (PCR) assay indicated a transformation efficiency of 8.33 %. The luciferase assay showed stable integration of the Arabidopsis thaliana HSP101 (AtHSP101) cDNA in the transgenic broccoli regenerants. Three out of five transgenic lines confirmed through PCR showed positive hybridization bands of the AtHSP101 cDNA through Southern blot analysis. The presence of AtHSP101 transcripts in the three transgenic broccoli lines indicated by reverse transcription-PCR (RT-PCR) confirmed the expression of the gene. In conclusion, an improved regeneration system has been established from hypocotyl explants of broccoli followed by successful transformation with AtHSP101 for resistance to high temperature. PMID:25986972

  14. Thermophilic spore-forming bacteria isolated from spoiled canned food and their heat resistance. Results of a French ten-year survey.

    Science.gov (United States)

    André, S; Zuber, F; Remize, F

    2013-07-15

    Thermal processing of Low Acid Canned Foods (LACF), which are safe and shelf-stable at ambient temperature for several years, results in heat inactivation of all vegetative microorganisms and the partial or total inactivation of spores. Good Manufacturing Hygienic Practices include stability tests for managing the pathogen risk related to surviving mesophilic bacterial spores. LACF are also often submitted to additional incubation conditions, typically 55 °C for 7 days, to monitor spoilage by thermophiles. In this study we identified the bacterial species responsible for non-stability after prolonged at 55 °C of incubation of LACF from 455 samples collected from 122 French canneries over 10 years. Bacteria were identified by microsequencing or a recent developed tool for group-specific PCR detection (SporeTraQ™). A single species was identified for 93% of examined samples. Three genera were responsible for more than 80% of all non-stability cases: mostly Moorella (36%) and Geobacillus (35%), and less frequently Thermoanaerobacterium (10%). The other most frequent bacterial genera identified were Bacillus, Thermoanaerobacter, Caldanaerobius, Anoxybacillus, Paenibacillus and Clostridium. Species frequency was dependent on food category, i.e. vegetables, ready-made meals containing meat, seafood or other recipes, products containing fatty duck, and related to the intensity of the thermal treatment applied in these food categories. The spore heat resistance parameters (D or ? and z values) from 36 strains isolated in this study were determined. Taken together, our results single out the species most suitable for use as indicators for thermal process settings. This extensively-documented survey of the species that cause non-stability at 55 °C in LACF will help canneries to improve the management of microbial contamination. PMID:23728430

  15. Mechanical long-term properties of nickel-base alloys for steam turbine bolting

    International Nuclear Information System (INIS)

    Within the reported project three heat resistant nickel-base alloys, Alloy 70 (NiCr 20 Fe 25 TiAl), Alloy 80A (NiCr 20 TiAl) and Alloy X-750 (NiCr 15 TiAl) were investigated for the application to steam turbine bolting in the temperature range of 450 to 600deg C. Important mechanical long-term properties as creep-rupture strength, relaxations strength and contraction were determined to improve the basis for the optimum selection of bolting materials. On the optimized condition of the three materials, some important interdependencies between different mechanical properties were investigated. Using creep and contraction data, it was possible to predict the time-dependent residual stress of the continuous relaxation test with sufficient accuracy. An inelastic finite element calculation of notched specimens of Alloy 80A for 550deg C short-term creep-rupture tests showed, that even under elastoplastic loading there is a risk to crack initiation in the vicinity of the notch. (orig./RHM) With 17 figs., 15 tabs

  16. Hydrogen solubility in alloys

    International Nuclear Information System (INIS)

    A mathematical equation for determining hydrogen solubility in different alloys under different external conditions: temperatures, pressures and concentrations of alloying elements, is derived. Hydrogen solubility in alloys Fe-Ti, Fe-V, Ti-V is calculated and solubility values in Nb-W and Fe-Sc alloys are predicted

  17. Corrosion resistance of Ni-Cr-Mo alloys. Chemical composition and metallurgical condition's effects

    International Nuclear Information System (INIS)

    Ni-Cr-Mo alloys offer an outstanding corrosion resistance in a wide variety of highly-corrosive environments. This versatility is due to the excellent performance of nickel in hot alkaline solutions and the beneficial effect of chromium and molybdenum in oxidizing and reducing conditions, respectively. Alloy C-22 (22 % Cr-13 % Mo-3% W) is a well known versatile member of this family. Due to its excellent corrosion resistance in a wide variety of environments, Alloy C-22 has been selected for the fabrication of the corrosion-resistant outer shell of the high-level nuclear waste container. The increasing demand of the industry for corrosion resistant alloys with particular properties of corrosion and mechanical resistance has led to the development of new alloys. Alloy C-22HS (Ni-21 % Cr-17 % Mo) is a new high-strength corrosion resistant material recently developed and introduced into the market. This alloy provides a corrosion resistance comparable with that of other C-type alloys, and it can also be age hardened to effectively double its yield strength. HASTELLOY HYBRID-BC1 (Ni-22 % Mo-15 % Cr) is a new development intended for filling the gap between Ni-Mo and Ni-Cr-Mo alloys. This novel alloy is able to withstand HCl and H2SO4, even in the presence of dissolved oxygen and other oxidizing species. Its resistance to chloride-induced pitting corrosion, crevice corrosion and stress corrosion cracking is also remarkable. Thermal aging of Ni-Cr-Mo alloys leads to microstructure changes depending on the temperature range and exposure time at temperature. A Long Range Ordering (LRO) reaction can occur in the range of 350 C degrees to 600 C degrees, producing an ordered Ni2(Cr,Mo) phase. This ordering reaction does not seem to affect the corrosion resistance and produces only a slight loss in ductility. LRO transformation is homogeneous and has proven to be useful to fabricate the age-hard enable Alloy C22-HS. Tetrahedral Close Packed (TCP) phases, like ?, ? and P, may form if Ni-Cr-Mo alloys are exposed for tens of hours in the range of 600 C degrees to 1100 C degrees. These phases could have a detrimental effect upon corrosion resistance and cause a loss of mechanical ductility. The precipitation of TCP phases starts at grain boundaries and for long aging times it progresses to twins boundaries and then the grain bodies. TCP phases are rich in Mo and Cr. Zones in the matrix adjacent to the TCP precipitates may be depleted of Cr and Mo, and the alloy becomes sensitized.The aim of the present work was to compare the general corrosion rate and the crevice corrosion susceptibility of alloys C-22, C-22HS and HYBRID-BC1 in different metallurgical conditions when exposed to hot chloride solutions. The effects of the alloy composition and different heat treatments were assessed. (author)

  18. Alloying considerations in gamma-based alloys

    International Nuclear Information System (INIS)

    The intermetallic compound gamma-TiAl has attracted a great deal of research interest because of its potential for high-temperature structural applications. The interest has recently intensified, because multi-phased alloys based on this compound are found to have improved processability and mechanical properties suitable for several uses. The improvements are largely a result of certain alloying considerations, such as the control of Ti/Al ratio and the addition of selected alloying elements. The purpose of this paper is to review those alloying considerations that are critical to the development of gamma-based alloys. 64 refs., 13 figs., 1 tab

  19. Metal alloy identifier

    Science.gov (United States)

    Riley, William D. (Avondale, MD); Brown, Jr., Robert D. (Avondale, MD)

    1987-01-01

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

  20. Hydrofluoric Acid Corrosion Study of High-Alloy Materials

    International Nuclear Information System (INIS)

    A corrosion study involving high-alloy materials and concentrated hydrofluoric acid (HF) was conducted in support of the Molten Salt Reactor Experiment Conversion Project (CP). The purpose of the test was to obtain a greater understanding of the corrosion rates of materials of construction currently used in the CP vs those of proposed replacement parts. Results of the study will help formulate a change-out schedule for CP parts. The CP will convert slightly less than 40 kg of 233U from a gas (UF6) sorbed on sodium fluoride pellets to a more stable oxide (U3O8). One by-product of the conversion is the formation of concentrated HF. Six moles of highly corrosive HF are produced for each mole of UF6 converted. This acid is particularly corrosive to most metals, elastomers, and silica-containing materials. A common impurity found in 233U is 232U. This impurity isotope has several daughters that make the handling of the 233U difficult. Traps of 233U may have radiation fields of up to 400 R at contact, a situation that makes the process of changing valves or working on the CP more challenging. It is also for this reason that a comprehensive part change-out schedule must be established. Laboratory experiments involving the repeated transfer of HF through 1/2-in. metal tubing and valves have proven difficult due to the corrosivity of the HF upon contact with all wetted parts. Each batch of HF is approximately 1.5 L of 33 wt% HF and is transferred most often as a vapor under vacuum and at temperatures of up to 250 C. Materials used in the HF side of the CP include Hastelloy C-276 and Monel 400 tubing, Haynes 230 and alloy C-276 vessels, and alloy 400 valve bodies with Inconel (alloy 600) bellows. The chemical compositions of the metals discussed in this report are displayed in Table 1. Of particular concern are the almost 30 vendor-supplied UG valves that have the potential for exposure to HF. These valves have been proven to have a finite life due to failure, most often at the bellows flange ring. It was discovered that the entire bellows assembly was not all alloy 600 but that alloy 600 bellows had been welded to a stainless steel alloy 316 (SS-316) flange ring. A previous study documents and addresses this problem.1 The fabricators of the valves immediately corrected the problem and began fabricating all wetted parts of the bellows assembly from alloy 600. At the same time, the fabricators began to make alloy C-276 valve bodies and stem tips available for sale. This material is known to be superior to the alloy 400 valve bodies and stem tips of the standard UG valves that had already been installed in the CP. A decision was made to purchase alloy C-276 bodies and stem tips and to change out those alloy 400 components that had already been installed. Due to the enormity of this task (both in terms of time and money), it was desirable to determine the longevity of alloy C-276 vs alloy 400 components in a side-by-side comparison. Also of interest was the question of how long the new (all-alloy 600) bellows would last in comparison with the original alloy 600/SS-316 bellows. A basic HF corrosion test was proposed to compare corrosion rates of several high-alloy materials. Because much of the alloy 400 in the system had been gold plated, some gold-plated alloy 400 coupons were included. Due to time and funding limitations, actual CP variables such as temperature and pressure were not duplicated. Instead, a simple partial-immersion test at ambient temperature was conducted. The purpose of this test was to gain information on the rate of corrosion of different alloys in the CP and to attempt to derive some idea of their expected lifetimes in the operating environment

  1. Effect of composition and structure on crevice, intergranular, and stress corrosion of some wrought Ni--Cr--Mo alloys

    International Nuclear Information System (INIS)

    The relationship of composition and microstructure to the occurrence of localized corrosion in Hastelloy alloys C, C-276, and C-4 was investigated. One hour exposures of these alloys in the range of 1200 to 22000F may result in the formation of a molybdenum-rich intermetallic compound and, in alloys with more than about 0.004 percent C, a molybdenum-rich carbide. The boiling ferric sulfate-50 percent H2SO4 test readily detects the presence of both of these precipitates which cause rapid intergranular attack in this solution. The molybdenum-rich M6C carbide precipitate impairs resistance to intergranular, crevice, and stress corrosion. In contrast, the molybdenum-rich intermetallic compound, Mo-phase impairs resistance only to intergranular attack, primarily in oxidizing acids. When the carbon content is progressively increased above 0.004 percent, formation of the molybdenum-rich carbide precipitate at grain boundaries by one hour heat treatment results first in loss of resistance to stress corrosion cracking (SCC) in the boiling 45 percent MgCl2 test. Further increases in carbon content (0.05 percent) result in loss of resistance to intergranular attack in acids, to crevice corrosion in 10 percent ferric chloride at 500C and also to SCC in this solution. All SCC is of the intergranular type. Formation of the molybdenum-rich carbide precipitate is prevented in alloy C-4 by keeping the carbon content low and by addition of titanium. Formation of the intermetallic compound is minimized by adjustment of the alloy content. In the heat investigated, titanium stabilization was effective in preventing intergranular attack in reducing acids and SCC in the MgCl2 test. However, metallographic examination and intergranular attack in the ferric sulfate test on material heated 1 hour at 16000F indicated that a compound was still being formed at grain boundaries

  2. Gas-metal reactions of a new Fe-Ni-Cr-W alloy in helium with reactive components and in an H2-CH4-H2S atmosphere in the temperature range 700-9500C

    International Nuclear Information System (INIS)

    A new heat resistant e-Ni-Cr-W alloy (Thermon 4972) was developed within the scope of the prototype nuclear process plant project. This alloy shows mechanical properties and creep rupture properties similar to those of the nickel-based alloy Inconel 617 but, in addition, the new alloy forms protective oxide layers in atmospheres with very low O2 partial pressures. It is shown, by means of some examples, that a variation in the oxide morphology is caused by the modification of the alloy. However, the modifications lead to changes in the carbon activity of the alloy in comparison with the carbon activity of the atmosphere. Both activities must be adjusted to avoid processes such as carburization or decarburization. The results of experiments carried out for durations up to 2000 h at temperatures between 750 and 9500C are compared with those of the alloy Inconel 617. Experiments in sulphidizing and carburizing gas atmospheres were carried out to examine the protective behaviour of the layers built up in H2-CH4-H2S atmospheres with H2O contents between 10% and 10-3%. It is shown that, with an increase in the O2 partial pressure, the layers change from sulphide to oxide. At the same time there is a large variation in the specific mass change. The results are important for the application of the new alloy in plants for coal conversion and are compared with those obtained with the alloy Inconel 800 H. (orig.)

  3. International research cooperation in fiscal 1997. Report on the development of novel magnesium alloy-base ultralight materials; 1997 nendo kokusai kenkyu kyoryoku jigyo. Magnesium gokin ni yoru chokeiryo shinzairyo no kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Research and development are conducted for the improvement of magnesium alloy characteristics and for the realization of energy and cost saving in the manufacturing process of the said alloys. Concerning manufacturing techniques for high-performance magnesium materials which are among the existing alloys, researches are conducted about the development of superplastic magnesium alloys, development of heat-resistant magnesium alloys, pulverizing techniques and the experimental construction of equipment therefor, safety of magnesium powder, high-precision strain control, processing for enhanced strength and superplasticity, and heat treatment and surface treatment technologies. In the efforts for developing technologies for manufacturing ultrahigh-performance magnesium materials which are novel alloys, researches are conducted concerning the manufacture of amorphous magnesium alloys and methods for evaluating the characteristics thereof, manufacture of amorphous magnesium alloys by a liquid-aided rapid cooling method and the characteristics of the products, and methods for forming the alloys into wires. The developed magnesium materials are tested for strength, resistance to corrosion, etc., and environmental impacts and friendliness toward environments that will eventually affect the life cycle of the new materials are discussed. 45 refs., 91 figs., 21 tabs.

  4. Bacillus thermoamylovorans Spores with Very-High-Level Heat Resistance Germinate Poorly in Rich Medium despite the Presence of ger Clusters but Efficiently upon Exposure to Calcium-Dipicolinic Acid.

    Science.gov (United States)

    Berendsen, Erwin M; Krawczyk, Antonina O; Klaus, Verena; de Jong, Anne; Boekhorst, Jos; Eijlander, Robyn T; Kuipers, Oscar P; Wells-Bennik, Marjon H J

    2015-11-15

    High-level heat resistance of spores of Bacillus thermoamylovorans poses challenges to the food industry, as industrial sterilization processes may not inactivate such spores, resulting in food spoilage upon germination and outgrowth. In this study, the germination and heat resistance properties of spores of four food-spoiling isolates were determined. Flow cytometry counts of spores were much higher than their counts on rich medium (maximum, 5%). Microscopic analysis revealed inefficient nutrient-induced germination of spores of all four isolates despite the presence of most known germination-related genes, including two operons encoding nutrient germinant receptors (GRs), in their genomes. In contrast, exposure to nonnutrient germinant calcium-dipicolinic acid (Ca-DPA) resulted in efficient (50 to 98%) spore germination. All four strains harbored cwlJ and gerQ genes, which are known to be essential for Ca-DPA-induced germination in Bacillus subtilis. When determining spore survival upon heating, low viable counts can be due to spore inactivation and an inability to germinate. To dissect these two phenomena, the recoveries of spores upon heat treatment were determined on plates with and without preexposure to Ca-DPA. The high-level heat resistance of spores as observed in this study (D120°C, 1.9 ± 0.2 and 1.3 ± 0.1 min; z value, 12.2 ± 1.8°C) is in line with survival of sterilization processes in the food industry. The recovery of B. thermoamylovorans spores can be improved via nonnutrient germination, thereby avoiding gross underestimation of their levels in food ingredients. PMID:26341201

  5. Assessment of Embrittlement of VHTR Structural Alloys in Impure Helium Environments

    Energy Technology Data Exchange (ETDEWEB)

    Crone, Wendy; Cao, Guoping; Sridhara, Kumar

    2013-05-31

    The helium coolant in high-temperature reactors inevitably contains low levels of impurities during steady-state operation, primarily consisting of small amounts of H{sub 2}, H{sub 2}O, CH{sub 4}, CO, CO{sub 2}, and N{sub 2} from a variety of sources in the reactor circuit. These impurities are problematic because they can cause significant long-term corrosion in the structural alloys used in the heat exchangers at elevated temperatures. Currently, the primary candidate materials for intermediate heat exchangers are Alloy 617, Haynes 230, Alloy 800H, and Hastelloy X. This project will evaluate the role of impurities in helium coolant on the stress-assisted grain boundary oxidation and creep crack growth in candidate alloys at elevated temperatures. The project team will: • Evaluate stress-assisted grain boundary oxidation and creep crack initiation and crack growth in the temperature range of 500-850°C in a prototypical helium environment. • Evaluate the effects of oxygen partial pressure on stress-assisted grain boundary oxidation and creep crack growth in impure helium at 500°C, 700°C, and 850°C respectively. • Characterize the microstructure of candidate alloys after long-term exposure to an impure helium environment in order to understand the correlation between stress-assisted grain boundary oxidation, creep crack growth, material composition, and impurities in the helium coolant. • Evaluate grain boundary engineering as a method to mitigate stress-assisted grain boundary oxidation and creep crack growth of candidate alloys in impure helium. The maximum primary helium coolant temperature in the high-temperature reactor is expected to be 850-1,000°C.Corrosion may involve oxidation, carburization, or decarburization mechanisms depending on the temperature, oxygen partial pressure, carbon activity, and alloy composition. These corrosion reactions can substantially affect long-term mechanical properties such as crack- growth rate and fracture toughness, creep rupture, and fatigue. Although there are some studies on the effects of impurities in helium coolant on creep rupture and fatigue strength, very little is known about their effects on creep crack initiation and crack growth rate at elevated temperatures.

  6. Effect of coating and surface modification on the corrosion resistance of selected alloys in supercritical water

    International Nuclear Information System (INIS)

    Materials selection is one of the key tasks in Gen-IV reactor development. There is no known material that can meet the expected core outlet conditions of the Canadian SCWR concept (625oC core outlet temperature). High-Cr steels with excellent corrosion resistance are often susceptible to embrittlement due to the precipitation of sigma and other phases in the microstructure. Low-Cr steels such as P91 and oxide dispersion strengthened (ODS) steels exhibit good high-temperature mechanical properties, but the lack of sufficient Cr content makes this group alloy corrode too fast. Improvement in this alloy is needed in order for it to be considered as a piping construction material. In this report, the development of a metallic coating on a P91 substrate is discussed. Recent effort on selection of in-core cladding alloys has focused on heat-resistant 3xx series stainless steels. These alloys have higher strength at high-temperature ranges, but corrosion and stress-corrosion cracking resistance are a concern. Metallic coating and surface modification are considered as possible solutions to overcome this challenge. The effects of surface modification on the corrosion rate of austenitic steels were also reported in this paper. As-machined surface showed much better corrosion resistance than polished surface and advanced surface analyses showed distinct differences in the nature and the morphology of the surface layer metal. Possible mechanisms for improved corrosion performance are discussed. (author)

  7. Ferroelectric and ferromagnetic properties of epitaxial BiFeO{sub 3}-BiMnO{sub 3} films on ion-beam-assisted deposited TiN buffered flexible Hastelloy

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, J., E-mail: jiexiong@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Los Alamos National Laboratory, Center for Integrated Nanotechnologies, Division of Materials Physics and Applications, Los Alamos, New Mexico 87545 (United States); Matias, V.; Jia, Q. X. [Los Alamos National Laboratory, Center for Integrated Nanotechnologies, Division of Materials Physics and Applications, Los Alamos, New Mexico 87545 (United States); Tao, B. W.; Li, Y. R. [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2014-05-07

    Growth of multifunctional thin films on flexible substrates is of great technological significance since such a platform is needed for flexible electronics. In this study, we report the growth of biaxially aligned (BiFeO{sub 3}){sub 0.5}:(BiMnO{sub 3}){sub 0.5} [BFO-BMO] films on polycrystalline Hastelloy by using a biaxially aligned TiN as a seed layer deposited by ion-beam-assisted deposited and a La{sub 0.7}Sr{sub 0.3}MnO{sub 3} (LSMO) as a buffer layer deposited by pulsed laser deposition. The LSMO is used not only as a buffer layer but also as the bottom electrode of the BFO-BMO films. X-ray diffraction showed that the BFO-BMO films are biaxially oriented along both in-plane and out-of-plane directions. The BFO-BMO films on flexible metal substrates showed a polarization of 22.9??C/cm{sup 2}. The magnetization of the BFO-BMO/LSMO is 62?emu/cc at room temperature.

  8. Phase and structural transformations in the Ni{sub 65}Mo{sub 20}Cr{sub 15} alloy at changing the temperature of heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ustinovshikov, Y., E-mail: ust@ftiudm.ru

    2014-03-05

    Highlights: • Crystalline Mo particles are formed in liquid alloy as a result of phase separation. • Below 1200 °C the high-dispersed phase separation structure forms in the Ni/Cr pair. • Below 1200 °C the Mo particles are dissolved in the Ni/Mo diffusional couple. • Prolonged 650 °C aging causes the Ni{sub 2}Mo formation in boundaries and embrittlement. -- Abstract: The ternary Ni{sub 65}Mo{sub 20}Cr{sub 15} alloy was studied using TEM after heat treatment at different temperatures. It has been shown that the tendency to phase separation which exists in the Ni/Mo diffusion couple at high temperatures leads to precipitation of crystalline particles of Mo atoms in the liquid solution. At lowering the heat treatment temperature to 1200 °C, a phase transition ordering – phase separation occurs in the Ni/Mo diffusion couple, which results in dissolution of the particles of Mo atoms. At 650 °C, there takes place precipitation of Ni{sub 2}Mo phase particles, which can initiate intercrystalline embrittlement of Hastelloy-type alloys.

  9. Processing and alloying of tungsten heavy alloys

    International Nuclear Information System (INIS)

    Tungsten heavy alloys are two-phase metal matrix composites with a unique combination of density, strength, and ductility. They are processed by liquid-phase sintering of mixed elemental powders. The final microstructure consists of a contiguous network of nearly pure tungsten grains embedded in a matrix of a ductile W-Ni-Fe alloy. Due to the unique property combination of the material, they are used extensively as kinetic energy penetrators, radiation shields. counterbalances, and a number of other applications in the defense industry. The properties of these alloys are extremely sensitive to the processing conditions. Porosity levels as low as 1% can drastically degrade the properties of these alloys. During processing, care must be taken to reduce or prevent incomplete densification, hydrogen embrittlement, impurity segregation to the grain boundaries, solidification shrinkage induced porosity, and in situ formation of pores due to the sintering atmosphere. This paper will discuss some of the key processing issues for obtaining tungsten heavy alloys with good properties. High strength tungsten heavy alloys are usually fabricated by swaging and aging the conventional as-sintered material. The influence of this on the shear localization tendency of a W-Ni-Co alloy will also be demonstrated. Recent developments have shown that the addition of certain refractory metals partially replacing tungsten can significantly improve the strength of the conventional heavy alloys. This development becomes significant due to the recent interest in near net shaping techniques such as powder injection moldings. The role of suitable alloying additions to the classic W-Ni-Fe based heavy alloys and their processing techniques will also be discussed in this paper

  10. 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.

  11. High strength alloys

    Science.gov (United States)

    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.

  12. 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.)

  13. An irradiation test of heat-resistant ceramic composite materials (2). Interim report on post-irradiation examinations of the second and third preliminary test: 98M-41A, 99M-30A

    International Nuclear Information System (INIS)

    The Japan Atomic Energy Research Institute (JAERI) has been carrying out the research on radiation damage mechanism of heat-resistant ceramic composite materials, as one of the subjects of the innovative basic research on high temperature engineering using the High Temperature Engineering Test Reactor (HTTR). A series of preliminary irradiation tests is being made using the Japan Materials Testing Reactor (JMTR). The present report describes results of post-irradiation examinations (PIE) so far on specimens irradiated in the second and third capsule, designated 98M-41A and 99M-30A, to fast neutron fluencies of 1.0x1025 m-2 (E > 1 MeV) at temperatures of 973-1173K and 1273-1473K. The PIE were conducted as the fundamental statistic index of the diametral dimensions for irradiated specimen, irradiation induced dimensional change rate and thermal expansion rate. (author)

  14. Identificação de cultivares de milho, feijão, algodão e soja por meio de enzimas e proteínas resistentes ao calor / Cultivars identification of corn, bean, cotton and soybean using enzymes and heat-resistant proteins

    Scientific Electronic Library Online (English)

    Mariney de, Menezes; Édila Vilela de Resende Von, Pinho; Antônio Marcos de Andrade Rezende, Pereira; João Almir de, Oliveira.

    Full Text Available Nesta pesquisa foram avaliados o polimorfismo e a estabilidade de isoenzimas e de proteínas resistentes ao calor em sementes de cultivares de milho, feijão, algodão e soja, com diferentes níveis de qualidade fisiológica. As isoenzimas ,álcool desidrogenase, catalase, esterase e superóxido dismutase [...] analisadas conjuntamente, foram eficientes na separação de oito cultivares de milho. Para as cultivares de feijão, pela enzima peroxidase foi possível diferenciar a cultivar Carioca, no entanto, este padrão mostrou-se variável em sementes com baixa germinação. Não foi possível diferenciar as cultivares de algodão pelas enzimas esterase, superóxido dismutase, diaforase e malato desidrogenase. A cultivar Conquista, de soja, foi diferenciada pelos sistemas enzimáticos esterase e superóxido dismutase e a 'BRS-154' pela esterase. Proteínas resistentes ao calor são polimórficas e estáveis para a identificação de cultivares de milho. Abstract in english In this study the polymorphism and stability of isoenzymes and heat-resistant proteins in corn, bean, cotton, and soybean seeds with different levels of physiological quality were evaluated. The alcohol dehydrogenase, catalase, esterase and superoxide dismutase enzymes and simultaneous analysis were [...] effective in identifying eight corn cultivars. It was observed for the bean cultivars that the peroxidase enzyme allowed differentiation of the Carioca bean cultivar from the others but, the peroxidase enzyme pattern varied in seeds with low-germination percentage. The varieties of cotton could not be differentiated by esterase enzyme, superoxide dismutase, diaphorase and malate dehydrogenase. The Conquista soybean cultivar was separated by superoxide dismutase and esterase enzyme systems and BRS-154 was separated by esterase. Heat-resistant protein patterns showed polymorphism and were stable for corn cultivar identification.

  15. Identificação de cultivares de milho, feijão, algodão e soja por meio de enzimas e proteínas resistentes ao calor Cultivars identification of corn, bean, cotton and soybean using enzymes and heat-resistant proteins

    Directory of Open Access Journals (Sweden)

    Mariney de Menezes

    2008-01-01

    Full Text Available Nesta pesquisa foram avaliados o polimorfismo e a estabilidade de isoenzimas e de proteínas resistentes ao calor em sementes de cultivares de milho, feijão, algodão e soja, com diferentes níveis de qualidade fisiológica. As isoenzimas ,álcool desidrogenase, catalase, esterase e superóxido dismutase analisadas conjuntamente, foram eficientes na separação de oito cultivares de milho. Para as cultivares de feijão, pela enzima peroxidase foi possível diferenciar a cultivar Carioca, no entanto, este padrão mostrou-se variável em sementes com baixa germinação. Não foi possível diferenciar as cultivares de algodão pelas enzimas esterase, superóxido dismutase, diaforase e malato desidrogenase. A cultivar Conquista, de soja, foi diferenciada pelos sistemas enzimáticos esterase e superóxido dismutase e a 'BRS-154' pela esterase. Proteínas resistentes ao calor são polimórficas e estáveis para a identificação de cultivares de milho.In this study the polymorphism and stability of isoenzymes and heat-resistant proteins in corn, bean, cotton, and soybean seeds with different levels of physiological quality were evaluated. The alcohol dehydrogenase, catalase, esterase and superoxide dismutase enzymes and simultaneous analysis were effective in identifying eight corn cultivars. It was observed for the bean cultivars that the peroxidase enzyme allowed differentiation of the Carioca bean cultivar from the others but, the peroxidase enzyme pattern varied in seeds with low-germination percentage. The varieties of cotton could not be differentiated by esterase enzyme, superoxide dismutase, diaphorase and malate dehydrogenase. The Conquista soybean cultivar was separated by superoxide dismutase and esterase enzyme systems and BRS-154 was separated by esterase. Heat-resistant protein patterns showed polymorphism and were stable for corn cultivar identification.

  16. Superplasticity in titanium alloys

    OpenAIRE

    J. Sieniawski; M. Motyka

    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...

  17. The effect of thermal treatment and welding on the mechanical properties of welded joints of molybdenum alloys within a wide temperature range

    International Nuclear Information System (INIS)

    The experimental data on the short-term strength and plasticity of the welded joint metal and welded junctions of the molybdenum base low alloys of the Mo-Al-B (TsM-10), Mo-Zr-B (TsM-6) and Mo-Hf-B (TsM-12) systems within the temperature range of 290-2270 K, obtained through arc welding in the controlled helium atmosphere and through electron-beam welding in vacuum, are presented. The welded joints were tested both at the initial state and after annealing. It is established, that the way of welding in the case of comparable velocities and linear energy values does not effect significantly mechanical properties of welded joints of the molybdenum alloys. Welding with increased velocities facilitates the growth of strength and plastic characteristics of the TsM-10 alloy welded joints. Welding with lower velocities is required for provision of the TsM-6 alloy heat resistance. It is recommended to perform high-temperature annealing of the above alloys welded joints, because embrittlement of welded joints is possible in this case on the account of in cease in the introduction admixtures concentration in the crystallite boundary zones

  18. Yttrium containing alloys

    International Nuclear Information System (INIS)

    A process for the production of alloys containing iron, chromium, aluminium and yttrium and/or rare earth metal or metals is described in which yttrium and/or rare earth metal or metals is added to a melt in the form of a master alloy having a melting point of less than 10000C. (author)

  19. Neutron Absorbing Alloys

    Science.gov (United States)

    Mizia, Ronald E. (Idaho Falls, ID); Shaber, Eric L. (Idaho Falls, ID); DuPont, John N. (Whitehall, PA); Robino, Charles V. (Albuquerque, NM); Williams, David B. (Bethlehem, PA)

    2004-05-04

    The present invention is drawn to new classes of advanced neutron absorbing structural materials for use in spent nuclear fuel applications requiring structural strength, weldability, and long term corrosion resistance. Particularly, an austenitic stainless steel alloy containing gadolinium and less than 5% of a ferrite content is disclosed. Additionally, a nickel-based alloy containing gadolinium and greater than 50% nickel is also disclosed.

  20. Nickel base coating alloy

    Science.gov (United States)

    Barrett, C. A. (inventor); Lowell, C. E. (inventor)

    1986-01-01

    Zirconium is added to a Ni-30 Al (beta) intermetallic alloy in the range of 0.05 w/o to 0.25 w/o. This addition is made during melting or by using metal powders. The addition of zirconium improves the cyclic oxidation resistance of the alloys at temperatures above 1100 C.

  1. 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.

  2. Alloys for aerospace

    International Nuclear Information System (INIS)

    Aerospace industries require special allows with many properties tailored to meet specific needs. Prerequisites include clean melting techniques to maintain low impurity levels, tight control of alloy chemistry, and the analytical capability to characterize the product. Teledyne Wah Chang (TWC) produces specially refractory metals, including zirconium, hafnium, titanium, niobium and vanadium, which are essential components of many aerospace alloys. Alloys are prepared by vacuum-arc-remelting (VAR) or electron beam (EB) melting, and ingots are processed to products ranging from bar and tube stock to wire and foil. Chemical, mechanical, and microstructural tests are all conducted at TWC's in-house laboratory facilities. Of the alloys described here, Ti-3Al-2.5V, Tiadyne 3515 (Alloy C), NiTiFe, and C-103 are produced commercially, while orthorhombic titanium aluminides are promising candidates for future light-weight composite matrices

  3. FRAUD/SABOTAGE Killing Nuclear-Reactors!!! ``Super"alloys GENERIC ENDEMIC Wigner's-Disease IN-stability!!!

    Science.gov (United States)

    Asphahani, Aziz; Siegel, Sidney; Siegel, Edward

    2010-03-01

    Siegel [[J.Mag.Mag.Mtls.7,312(78); PSS(a)11,45(72); Semis.& Insuls.5(79)] (at: ORNL, ANS, Westin``KL"ouse, PSEG, IAEA, ABB) warning of old/new nuclear-reactors/spent-fuel-casks/refineries/ jet/missile/rocket-engines austenitic/FCC Ni/Fe-based (so MIS- called)``super"alloys(182/82;Hastelloy-X; 600;304/304L-SSs; 690 !!!) GENERIC ENDEMIC EXTANT detrimental(synonyms): Wigner's- diseas(WD)[J.Appl.Phys.17,857(46)]; Ostwald-ripening; spinodal- decomposition; overageing-embrittlement; thermomechanical- INstability: Mayo[Google: ``If Leaks Could Kill"; at flickr.com search on ``Giant-Magnotoresistance"; find: [Siegel<<<``Fert"(88) 2007-Nobel/Wolf/Japan-prizes]necessitating NRC inspections on 40+25=65 Westin``KL"ouse PWRs(12/06)]; Lai[Met.Trans.AIME,9A,827 (78)]-Sabol-Stickler[PSS(70)]; Ashpahani[Intl.Conf. H in Metals (77)]; Russell[Prog. Mtls.Sci.(83)]; Pollard[last UCS rept. (9/95)]; Lofaro[BNL/DOE/NRC Repts.]; Pringle[Nuclear-Power:From Physics to Politics(79)]; Hoffman[animatedsoftware.com],...what DOE/NRC MISlabels as ``butt-welds" ``stress-corrosion cracking" endpoint's ROOT-CAUSE ULTIMATE-ORIGIN is WD overageing-embrit- tlement caused brittle-fracture cracking from early/ongoing AEC/DOE-n``u''tional-la``v''atories sabotage!!!

  4. FRAUD/SABOTAGE Killing Nuclear-Reactors Need Modeling!!!: ``Super'' alloys GENERIC ENDEMIC Wigner's-Disease/.../IN-stability: Ethics? SHMETHICS!!!

    Science.gov (United States)

    O'Grady, Joseph; Bument, Arlden; Siegel, Edward

    2011-03-01

    Carbides solid-state chemistry domination of old/new nuclear-reactors/spent-fuel-casks/refineries/jet/missile/rocket-engines is austenitic/FCC Ni/Fe-based (so miscalled)"super"alloys(182/82;Hastelloy-X,600,304/304L-SSs,...690!!!) GENERIC ENDEMIC EXTANT detrimental(synonyms): Wigner's-disease(WD) [J.Appl.Phys.17,857 (46)]/Ostwald-ripening/spinodal-decomposition/overageing-embrittlement/thermal-leading-to-mechanical(TLTM)-INstability: Mayo[Google: fLeaksCouldKill > ; - Siegel [ J . Mag . Mag . Mtls . 7 , 312 (78) = atflickr . comsearchonGiant - Magnotoresistance [Fert" [PRL(1988)]-"Gruenberg"[PRL(1989)] 2007-Nobel]necessitating NRC inspections on 40+25=65 Westin"KL"ouse PWRs(12/2006)]-Lai [Met.Trans.AIME, 9A,827(78)]-Sabol-Stickler[Phys.Stat.Sol.(70)]-Ashpahani[ Intl.Conf. Hydrogen in Metals, Paris(1977]-Russell [Prog.Mtls.Sci.(1983)]-Pollard [last UCS rept.(9/1995)]-Lofaro [BNL/DOE/NRC Repts.]-Pringle [ Nuclear-Power:From Physics to Politics(1979)]-Hoffman [animatedsoftware.com], what DOE/NRC MISlabels as "butt-welds" "stress-corrosion cracking" endpoint's ROOT-CAUSE ULTIMATE-ORIGIN is WD overageing-embrittlement caused brittle-fracture cracking from early/ongoing AEC/DOE-n"u"tional-la"v"atories sabotage!!!

  5. SURFACE MELTING OF ALUMINIUM ALLOYS

    OpenAIRE

    Veit, S; Albert, D.; Mergen, R.

    1987-01-01

    The wear properties of aluminium base alloys are relatively poor. Laser surface melting and alloying has proved successful in many alloy systems as a means of significantly improving the surface properties. The present work describes experiments designed to establish the scope of laser treatment of aluminium alloys. Aluminium does not absorb CO2 laser light as well as other metals which necessitated first a general study of absorption caotings. Aluminium alloys offer fewer opportunities than ...

  6. Technetium and technetium alloys

    International Nuclear Information System (INIS)

    This report presents the results of a literature survey on technetium and technetium alloys. The literature has been searched through 1993. The survey was focused on technetium and (binary cubic) technetium alloys, but other important information on technetium has not been omitted from this survey. This report has been written with the aim to collect more information about phase systems which could be of importance in the transmutation process by neutrons of technetium. With the information presented in this report, it should be possible to select a suitable technetium alloy for further investigation regarding to the transmutation process. (orig.)

  7. Titanium nitride strengthened alloys

    International Nuclear Information System (INIS)

    A titanium containing stainless steel or a nickel base alloy containing titanium and chromium is atomised in a nitrogen atmosphere and the nitrided product blended with the same alloy atomised in argon, in proportions to give an overall nitrogen content equal to that required for stoichiometric titanium nitride in the blend. The blended powder is then homogenised at a temperature at which nitrides of iron and/or chromium dissociate and the free nitrogen reacts with titanium in the argon-atomised powder to produce a powder which can be formed into artifacts, by hot isostatic pressing e.g. for nuclear reactors, of titanium nitride strengthened alloy. (author)

  8. Re-formation and re-crystallisation behaviour of ?'-free ODS nickel-based alloy PM 1000

    International Nuclear Information System (INIS)

    The aim of this work was the examination of the coarse grain recrystallisation of the ?-free ODS nickel-based alloy PM 1000 depending on the various parameters due to the processing during heat treatment. After isotropic hot compacting (HIP) of the mechanically alloyed powder, one observes a homogeneous sub-microscopic fine grain structure which can coarsen during high temperature heat treatment, due to sufficiently high driving force from the grain boundary energy via abnormal grain growth to 600 times its size. The setting of the elongated high temperature resistant recrystallisation structure is, however, not connected with this. The dependence of the sucess of re-crystallisation on the re-forming parameters (re-forming temperature and degree of re-forming) was shown by a socalled re-forming card. In order to achieve re-crystallisation to a coarse and aligned grain structure, apart from a certain absolute minimum degree of re-forming, the re-forming must occur within a defined temperature window. The factor which considerably affects the grain size of the re-crystallisation structure which is finally achievable via heat treatment, is the primary grain size of the re-forming structure. After setting a corresponding re-forming fine structure by choosing suitable re-forming parameters, the alloy PM 1000 can be successfully converted into a coarse-grained heat-resistant re-crystallisation structure via isothermal heat treatment. (MM)

  9. Magnesium Granulated Alloys Processing

    International Science & Technology Center (ISTC)

    Development of a Principle New Basic Technology for Magnesium Granulated Alloys Processing by the Method of Extrusion in Semi-Liquid (semi-Solid) Condition in Order to Obtain Long Shaped Blanks, Round Billets, and Bars of Near Net Shape

  10. Electroplating on titanium alloy

    Science.gov (United States)

    Lowery, J. R.

    1971-01-01

    Activation process forms adherent electrodeposits of copper, nickel, and chromium on titanium alloy. Good adhesion of electroplated deposits is obtained by using acetic-hydrofluoric acid anodic activation process.

  11. Positrons in amorphous alloys

    International Nuclear Information System (INIS)

    Positron annihilation techniques give interesting informations about ''empty spaces'' in amorphous alloys. The results of an extensive research work on the properties of either pre-existing or irradiation induced ''empty spaces'' in four amorphous alloys are presented. The pre-existing empty spaces appear to be small vacancy-like defects. The irradiation induced defects are ''close pairs'' with widely distributed configurations. There is a strong interaction between vacancy like and interstitial like components. A model is proposed, which explains the radiation resistance mechanism of the amorphous alloys. An extensive joint research work to study four amorphous alloys, Fe80B20,Fe40Ni40P14B6, Cu50Ti50, Pd80Si20, is summarized

  12. Scandium alloying of aluminium copper-containing alloys

    International Nuclear Information System (INIS)

    Scandium alloyed commercial alloys on the basis of the Al-Mg, Al-Zn-Mg, Al-Mg-Li systems have been worked out. Scandium alloying of aluminium alloys containing copper as alloyng component should be realized with caution, since scandium binds copper into a chemical compound. As a result strength poroperties of semifinished products, as well as their ductility and fracture toughness, deteriorate due to increase in the volumetric part of excess phases. Conditions of scandium alloying of copper-containing aluminium alloys have been defined. 9 refs.; 5 figs.; 4 tabs

  13. 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.

  14. 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

  15. Ultrahigh temperature intermetallic alloys

    International Nuclear Information System (INIS)

    A new family of Cr-Cr2Ta intermetallic alloys based on Cr-(6--10)Ta (at.%) is under development for structural use in oxidizing environments in the 1,000-1,300 C (1,832--2,372 F) temperature range. Development objectives relate to high temperature strength and oxidation resistance and room temperature fracture toughness. The 1,200 C (2,192 F) strength goals have been met: yield and fracture strengths of 275 MPa (40 ksi) and 345 MPa (50 ksi), respectively, were achieved. Progress in attaining reasonable fracture toughness of Cr-Cr2Ta alloys has been made; current alloys exhibit room-temperature values of about 10--12 MPa?m (1.1 MPa?m = 1 ksi?in.). Oxidation rates of these alloys at 950 C (1,742 F) in air are in the range of those reported for chromia-forming alloys. At 1,100 C (2,012 F) in air, chromia volatility was significant but, nevertheless, no scale spallation and positive weight gains of 1--5 mg/cm2 have been observed during 120-h, 6-cycle oxidation screening tests. These mechanical and oxidative properties represent substantial improvement over Cr-Cr2Nb and Cr-Cr2Zr alloys previously developed

  16. Mechanical alloying of Ti-Ni alloys under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Dobromyslov, A.V.; Churbaev, R.V.; Elkin, V.A.; Trenogina, T.L.

    1999-10-08

    The formation and properties of amorphous alloys have been the subject of a large amount of research. Amorphous alloys have been obtained in recent years by rapid quenching from the liquid state or by mechanical alloying in a planetary mill. Moreover metals and alloys in amorphous or nanocrystalline states can be processed by intense plastic deformation under high pressure. One advantage of this method is that it makes it possible to obtain new materials from powders of different elements, which are immiscible in the liquid state. At the present time, investigations devoted to producing amorphous alloys by mechanical alloying under high pressure are still scarce. So the primary purpose of the present research was to study the microstructure and phase constitution of Ti-Ni alloys produced from powders of pure metals by mechanical alloying under high pressure.

  17. 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 ...

  18. Microhardness of some phases in Mg-Sm-Y and Mg-Sm-Zn alloys

    International Nuclear Information System (INIS)

    Microhardness method is used to determine comparative heat resistance of some phases in Mg-Sm-Y and Mg-Sm-Zn systems. With respect to heat resistance compounds may be placed in the following sequence: Mg24Y5, X, Mg41Sm5, Y, Z and eutectoid ?+MgZn. Samarium dissolution in Mg24Y5 phase and ittrium or zinc dissolution in Mg41Sm5 phase promotes to increase their heat resistance

  19. Finding the Alloy Genome

    Science.gov (United States)

    Hart, Gus L. W.; Nelson, Lance J.; Zhou, Fei; Ozolins, Vidvuds

    2012-10-01

    First-principles codes can nowadays provide hundreds of high-fidelity enthalpies on thousands of alloy systems with a modest investment of a few tens of millions of CPU hours. But a mere database of enthalpies provides only the starting point for uncovering the ``alloy genome.'' What one needs to fundamentally change alloy discovery and design are complete searches over candidate structures (not just hundreds of known experimental phases) and models that can be used to simulate both kinetics and thermodynamics. Despite more than a decade of effort by many groups, developing robust models for these simulations is still a human-time-intensive endeavor. Compressive sensing solves this problem in dramatic fashion by automatically extracting the ``sparse model'' of an alloy in only minutes. This new paradigm to model building has enabled a new framework that will uncover, automatically and in a general way across the periodic table, the important components of such models and reveal the underlying ``genome'' of alloy physics.

  20. 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...

  1. Superplasticity in titanium alloys

    Directory of Open Access Journals (Sweden)

    J. Sieniawski

    2007-09-01

    Full Text Available 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 considered too. Mechanical properties of superplastic deformed titanium alloys, determining criteria of their potential applications, were also addressed.Research limitations/implications: Application of superplastic forming (SPF in industry is limited due to long time and high temperature of the forming process. In the paper directions of the studies were presented which can lead to increase in effectiveness of the process.Practical implications: SPF enables manufacturing of complex shape details in one-step technological operation. Together with diffusion bonding (DB it offers particular advantages making possible to manufacture complicated multilayer structures.Originality/value: The paper summarizes achievements of the studies on the superplasticity of Ti alloys, emphasizes the role of microstructural parameters and methods of their modification leading to better results and economics of SPF.

  2. De-alloyed platinum nanoparticles

    Science.gov (United States)

    Strasser, Peter (Houston, TX); Koh, Shirlaine (Houston, TX); Mani, Prasanna (Houston, TX); Ratndeep, Srivastava (Houston, TX)

    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.

  3. Superplastic aluminum alloys containing scandium

    International Nuclear Information System (INIS)

    This patent describes a method of superplastic forming wherein aluminum alloy stock is brought to superplastic forming temperature and superplastically formed into a shaped form at superplastic forming temperature. The improvement described here consists of providing the aluminum alloy stock as an alloy comprising more than 50% aluminum and including 0.05 to 10% scandium

  4. Semiconductor alloys - Structural property engineering

    Science.gov (United States)

    Sher, A.; Van Schilfgaarde, M.; Berding, M.; Chen, A.-B.

    1987-01-01

    Semiconductor alloys have been used for years to tune band gaps and average bond lengths to specific applications. Other selection criteria for alloy composition, and a growth technique designed to modify their structural properties, are presently considered. The alloys Zn(1-y)Cd(y)Te and CdSe(y)Te(1-y) are treated as examples.

  5. 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

  6. 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

  7. Heat resistant polymers of oxidized styrylphosphine

    Science.gov (United States)

    Paciorek, K. J. L. (inventor)

    1980-01-01

    A flame resistant, nontoxic polymer which may be used safely in confined locations where there is inadequate ventilation is prepared either by polymerizing compounds having the formula R-N=P(C6H5)2(C6H4)CH=CH2 where R is an organic moeity selected from the group of (C6H5)2P(O)-, (C6H5O)2P(O)-, (C6H5)2 C3N3-, or their mixtures, or by reacting a polymer with an organic azide such as diphenylphosphinylazide, diphenyl-phosphorylazide, 2-azido-4,6-diphenly-5-triazine, 2,4-diazido-6-phenyl-s-triazine, trimethylsilyoazide, triphenylsilylazine, and phenylazine. The reaction of the styrylphosphine with the organozaide results in the oxidation of the trivalent phosphorus atom to the pentavalent state in the form of an unsaturated P=N linkage known as a phosphazene group.

  8. FRAUD/SABOTAGE Killing Nuclear-Reactors Need Modeling!!!: "Super"alloys GENERIC ENDEMIC Wigner's-Disease/.../IN-stability: Ethics? SHMETHICS!!!

    Science.gov (United States)

    Asphahani, Aziz; Siegel, Sidney; Siegel, Edward

    2010-03-01

    Carbides solid-state chemistry domination of old/new nuclear- reactors/spent-fuel-casks/refineries/jet/missile/rocket-engines in austenitic/FCC Ni/Fe-based(so miscalled)``super"alloys(182/82; Hastelloy-X,600,304/304L-SSs,...,690!!!) GENERIC ENDEMIC EXTANT detrimental(synonyms): Wigner's-diseas(WD)[J.Appl.Phys.17,857 (1946)]/Ostwald-ripening/spinodal-decomposition/overageing- embrittlement/thermal-leading-to-mechanical(TLTM)-INstability: Mayo[Google:``If Leaks Could Kill"; at flickr.com search on ``Giant-Magnotoresistance"; find: Siegel[J.Mag.Mag.Mtls.7,312 (1978)]<<<``Fert"-"Gruenberg"(1988/89)2007-physics Nobel/Wolf/ Japan-prizes]necessitating NRC-inspections of 40+25 = 65 Westin- ``KLouse PWRs(12/2006)]-Lai[Met.Trans.AIME,9A,827(1978)]-Sabol- Stickler[Phys.Stat.Sol.(1970)]-Ashpahani[Intl.Conf. H in Metals, Paris(1977]-Russell[Prog.Mtls.Sci.(1983)]-Pollard[last UCS rept. (9/1995)]-Lofaro[BNL/DOE/NRC Repts.]-Pringle[Nuclear-Power:From Physics to Politics(1979)]-Hoffman[animatedsoftware.com], what DOE/NRC MISlabels as ``butt-welds" ``stress-corrosion cracking" endpoint's ROOT-CAUSE ULTIMATE-ORIGIN is WD overageing-embritt- lement caused brittle-fracture cracking from early/ongoing AEC/ DOE-n"u"tional-la"v"atories sabotage!!!

  9. 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.)

  10. Tungsten Alloy Outgassing Measurements

    CERN Document Server

    Rutherfoord, John P; Shaver, L

    1999-01-01

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

  11. 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)

  12. 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)

  13. Vacuum metallurgy of hard alloys

    International Nuclear Information System (INIS)

    Vacuum technology is described for hard alloys fabrication which has been developed in connection with designing a new group of low tungsten and tungstenless alloys on the base of TiC-Ni-Mo system. iIt is recommended to sinter low-tungsten cobalt-containing hard alloys under residual pressure not lower 66.5 Pa to prevent cobalt evaporation. It is shown that alloys sintered in vacuum at 1300 deg C possess improved microstructure, enchanced density, but decreased strength comparing to alloys treated in hydrogen. To increase strength and to refine structure hydrostatic compacting of preliminary sintered alloys should be carried out. Designs and specifications of commercial vacuum furnaces for hard alloys sintering are presented

  14. Joining of zirconium alloys

    International Nuclear Information System (INIS)

    Alloys of zirconium are widely used in various core components of power reactors. Nuclear assemblies require high degree of reliability and integrity for performing in radiation and corrosive atmosphere. The hostile environments of reactor core and inaccessibility for repairs make it mandatory to select only those joining techniques which produce not only superior quality but are also amenable to NDT methods and such other techniques which ensure acceptable performance. The author has worked on various types of welding of zirconium alloys for different applications. Modern techniques in electron beam (EB) welding, resistance welding, GTAW welding and laser welding have been developed for joining Zr alloys components for different types of reactors. Many of these have been standardized and successfully used in production. Several advancements have been made in the welding technologies towards achieving high productivity and increased reliability with economy and adaptability. EB, laser, ultrasonic and magnetic pulse welding have been studied as alternate methods and their feasibility evaluated. Some of them are found to be potentially acceptable processes and have been used for such applications. The paper evaluates these techniques for different applications including spacer joining, end closure welding, circumferential welding and appendage joining. Zirconium alloys are also construction materials for chemical industries and hence welding of zirconium is of interest to chemical industries. The joint requirements are different than those specified for nuclear components. The paper discusses various techniques and processes with a view to select most appropriate method in each case. (author)

  15. Yttrium containing alloys

    International Nuclear Information System (INIS)

    An oxidation-resistant alloy is described containing apart from impurities, 1 to 20% by weight chromium, 0.5 to 12% by weight aluminium, 0.1 to 3% by weight yttrium, balance iron, the yttrium being partially or totally replaced with one or more rare earth metals. (author)

  16. 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.

  17. Fracture of uranium alloys

    International Nuclear Information System (INIS)

    Since the fracture of uranium and its alloys has received little emphasis in the open literature, the first objective of this paper is to review past and current research in this area. Fracture toughness (K/sub Ic/) values for uranium alloys are compared to those for frequently used structural materials, with emphasis placed on work relating fracture behavior to microstructure and tensile behavior. Recent investigations concerned with the prediction of K/sub Ic/ and the development of simple but reliable fracture toughness test methods are discussed. The second objective of the paper is to describe an investigation of the fracture behavior of U--3/4 Ti and U--2 1/4 Nb. The research pursued two goals: (1) Characterizing the alloys' fracture toughness in a variety of service environments: The effects of strain rate, temperature, and humidity upon the fracture toughness of U--3/4 Ti and U--2 1/4 Nb were measured. (2) Relating fracture toughness to microstructural conditions. The fracture toughness of U--2 1/4 Nb was significantly improved through careful heat treating. This improvement is related to microstructural changes produced in the alloy and correlated to changes in fracture mode. In addition, the effects of shear forming and hydrogen content upon the fracture behavior of U--3/4 Ti were investigated. (9 tables, 18 figures, 73 references) (U.S.)

  18. Hardening of niobium alloys at precrystallization annealing

    International Nuclear Information System (INIS)

    Niobium base alloys were investigated. It is shown that precrystallization annealing of niobium-molybdenum, niobium-vanadium and niobium-zirconium alloys elevates much more sufficiently their resistance to microplastic strains, than to macroplastic strains. Hardening effect differs sufficiently for different alloys. The maximal hardening is observed for niobium-vanadium alloys, the minimal one - for niobium-zirconium alloys

  19. 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.

  20. 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

  1. Filler metal alloy for welding cast nickel aluminide alloys

    Science.gov (United States)

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

    1998-01-01

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

  2. 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.

  3. SINTERED REFRACTORY TUNGSTEN ALLOYS. Gesinterte hochschmelzende wolframlegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Kieffer, R.; Sedlatschek, K.; Braun, H.

    1971-12-15

    Dependence of the melting point of the refractory metals on their positions in the periodic system - alloys of tungsten with other refractory metals - sintering of the alloys - processing of the alloys - technological properties.

  4. 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

  5. Alloy Interface Interdiffusion Modeled

    Science.gov (United States)

    Bozzolo, Guillermo H.; Garces, Jorge E.; Abel, Phillip B.

    2003-01-01

    With renewed interest in developing nuclear-powered deep space probes, attention will return to improving the metallurgical processing of potential nuclear fuels so that they remain dimensionally stable over the years required for a successful mission. Previous work on fuel alloys at the NASA Glenn Research Center was primarily empirical, with virtually no continuing research. Even when empirical studies are exacting, they often fail to provide enough insight to guide future research efforts. In addition, from a fundamental theoretical standpoint, the actinide metals (which include materials used for nuclear fuels) pose a severe challenge to modern electronic-structure theory. Recent advances in quantum approximate atomistic modeling, coupled with first-principles derivation of needed input parameters, can help researchers develop new alloys for nuclear propulsion.

  6. Beryllium and beryllium alloys

    International Nuclear Information System (INIS)

    Age-hardening CuBe, CuCoBe, and NiBe alloys are casting and malleable materials widely used, especially in electrical engineering. Their chemical composition, physical and mechanical properties, the heat treatment required for hardening, and guidelines for the selection of materials are given. Beryllium itself is processed as a product obtained by powder-metallurgical methods. It is characterized by its high Young's modulus (300 x 103 N/mm2), low density (1.84 g/cm3) and good thermal properties. The BeAl alloy Lockalloy plays a role in aeronautics and astronautics. Beryllium oxide has the highest thermal conductivity of all ceramic materials known, along with a high electrical resistivity and a good microwave permeability. Its main technical data are presented in tables. (orig.)

  7. Ultralight Magnesium-Lithium Alloys

    OpenAIRE

    A. Bia?obrzeski; Saja, K; K. Hubner

    2007-01-01

    The article gives basic information on the chief constituents of Mg-Li alloys and on their expected properties. A schematic representation and technical performance of a pilot stand for melting and pouring of reactive ultralight magnesium-based alloys have been presented. The preliminary data regarding the manufactured magnesium alloys with about 2-3 % Li and about 10 % Li have been given in the form of microstructures and chemical compositions.

  8. Multicomponent and High Entropy Alloys

    Directory of Open Access Journals (Sweden)

    Brian Cantor

    2014-08-01

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

  9. Electrodeposition of engineering alloy coatings

    DEFF Research Database (Denmark)

    Christoffersen, Lasse

    2000-01-01

    Nickel based electrodeposited alloys were investigated with respect to their deposition process, heat treatment, hardness, corrosion resistance and combined wear-corrosion resistance. The investigated alloys were Ni-B, Ni-P and Ni-W, which are not fully developed for industrial utilisation at the moment. It was the intention of this study to investigate whether the mentioned alloy processes are able to substitute conventional deposition techniques for wear and corrosion resistance, namely Ni-P p...

  10. Surface Segregation in Ternary Alloys

    Science.gov (United States)

    Good, Brian; Bozzolo, Guillermo H.; Abel, Phillip B.

    2000-01-01

    Surface segregation profiles of binary (Cu-Ni, Au-Ni, Cu-Au) and ternary (Cu-Au-Ni) alloys are determined via Monte Carlo-Metropolis computer simulations using the BFS method for alloys for the calculation of the energetics. The behavior of Cu or Au in Ni is contrasted with their behavior when both are present. The interaction between Cu and Au and its effect on the segregation profiles for Cu-Au-Ni alloys is discussed.

  11. Titanium alloys for aerospace applications

    Energy Technology Data Exchange (ETDEWEB)

    Peters, M.; Leyens, C. [DLR-German Aerospace Center, D-51170 Koeln (Germany); Kumpfert, J. [Airbus Industrie, F-31707 Blagnac (France); Ward, C.H. [US Air Force Research Laboratory, London NW1 5TH (United Kingdom)

    2003-06-01

    There is probably no other material more closely related to aerospace than titanium and its alloys. With a density of 4.5 g/cm{sup 3}, titanium alloys are only about half as heavy as steel or Ni-based superalloys, yielding an excellent strength-to-weight ratio. Furthermore, they have exceptional corrosion resistance. The use of titanium alloys in the aerospace sector will be highlighted including airframe, engine, helicopter, and space applications. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  12. Research and application of superplastic forming titanium alloys for commercial aircraft parts

    Energy Technology Data Exchange (ETDEWEB)

    Gershon, B.; Eldror, I. [Israel Aircraft Industries, Ben Gurion International Airport, Lod (Israel)

    2005-07-01

    Titanium alloys sheets have many attractions for the aerospace industry owing to their high strength, low density, heat resistance and other useful properties. Many of the sheet metal structures in airframes have complex shapes and compound curvatures with intricate details. Superplastic forming (SPF), a most recent advancement in titanium sheet forming technology, exploits the excellent characteristic of >1000% elongation potential for the fabrication of complex configurations not achievable by conventional methods. SPF technology can also reduce manufacturing cost by shortening the preparation time, eliminating the need for extensive welding or other joining methods and by reducing the number of manufacturing steps. Consequently, high profit margins may be achieved in serial aircraft production. This paper outlines the research at Israel Aircraft Industries (IAI) of SPF technology and its application in producing complex-shape Ti sheet parts for the new IAI commercial aircrafts, models ''G-150'' and ''G-200''. Examples of both actual and experimental parts are given, together with details of the manufacturing parameters employed. An economical analysis is also included. (orig.)

  13. Alloy catalyst material

    DEFF Research Database (Denmark)

    Stephens, Ifan Technical University of Denmark,

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

  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. Low activation ferritic alloys

    International Nuclear Information System (INIS)

    This patent describes a ferritic alloy having a banitic or martensitic microstructure when heated treated and tempered and characterized by low activation properties, the alloy consisting essentially of: chromium-2.0 to 13 percent by weight; vanadium or, tungsten, or tantalum in a total amount of-0.3 to 1.5 percent by weight; carbon-0.75 to 0.30 percent by weight; manganese-0.01 to 15.0 percent by weight; silicon-0.05 to 1.0 percent by weight; phosphorous-less than 0.01 percent by weight; nitrogen-less than 0.04 percent by weight; sulphur-less than 0.01 percent by weight; copper-less than 0.003 percent by weight; molybdenum-less than 0.12 percent by weight; niobium-less than 0.003 percent by weight; nickel-less than 0.1 percent by weight; the remainder of the alloy being iron

  16. 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.

  17. Laser surface alloying of aluminium-transition metal alloys

    Directory of Open Access Journals (Sweden)

    Almeida, A.

    1998-04-01

    Full Text Available Laser surface alloying has been used as a tool to produce hard and corrosion resistant Al-transition metal (TM alloys. Cr and Mo are particularly interesting alloying elements to produce stable highstrength alloys because they present low diffusion coefficients and solid solubility in Al. To produce Al-TM surface alloys a two-step laser process was developed: firstly, the material is alloyed using low scanning speed and secondly, the microstructure is modified by a refinement step. This process was used in the production of Al-Cr, Al-Mo and Al-Nb surface alloys by alloying Cr, Mo or Nb powder into an Al and 7175 Al alloy substrate using a CO2 laser. This paper presents a review of the work that has been developed at Instituto Superior Tecnico on laser alloying of Al-TM alloys, over the last years.

    En el presente trabajo se estudia la aleación superficial mediante láser de aluminio con metales de transición. El cromo y el molibdeno son particularmente interesantes porque producen aleaciones de alta resistencia y por el bajo coeficiente de difusión y solución sólida en aluminio. Para producir estas aleaciones se ha seguido un procedimiento desarrollado en dos partes. En primer lugar, el material se alea usando una baja velocidad de procesado y en segundo lugar la estructura se modifica mediante un refinamiento posterior. Este procedimiento se ha empleado en la producción de aleaciones Al-Cr, Al-Mo y Al-Nb mediante aleación con láser de CO2 de polvos de Cr, Mo o Nb en aluminio y la aleación 7175. Este trabajo es una revisión del desarrollado en el Instituto Superior Técnico de Lisboa en los últimos años.

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

    International Nuclear Information System (INIS)

    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 are underway aimed at specific engineering and process requirements, both in the aerospace and non-aerospace sectors. Both the advanced high temperature and conventional alloy developments are considered, before the paper goes on to assess the potential of new processes and products, like spray-forming, metal matrix composites and shaped-plate rolling. (orig.)

  19. Large plastic stability in magnesium alloys: crystalline vs. amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Boissiere, R.; Puech, S.; Blandin, J.J. [Institut National Polytechnique de Grenoble (INPG), SIMaP Laboratory - GPM2 group, CNRS/UJF, Domaine Universitaire, Saint-Martin d' Heres (France)

    2008-04-15

    Except if strain induces damage, the plastic stability can be roughly estimated thanks to the value of the strain rate sensitivity parameter m. In conventional magnesium alloys, moderate values of m (typically close to 0.3) can be frequently obtained during high temperature deformation. Such values allow reaching significant elongations to fracture. For alloys displaying fine grains, superplastic properties associated with values of m of about 0.5 or more are achievable leading to large elongations to fracture in optimized conditions for which damage processes remain limited. Quite recently, amorphous magnesium alloys have been produced in bulk conditions. In appropriate conditions of deformation, these alloys display Newtonian behaviour (i.e. m=1). With such rheologies, the plastic stability is expected to be maximal. In this presentation, features in relation with high temperature deformation of amorphous and crystalline magnesium alloys will be compared and apparent similitudes and differences will be discussed. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  20. Alloy selection for exhaust valves

    International Nuclear Information System (INIS)

    Methods of selecting materials for use in exhaust valves are reviewed. The designs considered are those for use in single alloys for light duty to multiple alloy composites for heavy duty compositions and properties of exhaust valve materials are tabulated and discussed. (U.S.)

  1. An imperative extension to Alloy

    OpenAIRE

    Near, Joseph Paul; Jackson, Daniel

    2010-01-01

    We extend the Alloy language with the standard imperative constructs; we show the mix of declarative and imperative constructs to be useful in modeling dynamic systems. We present a translation from our extended language to the existing first-order logic of the Alloy Analyzer, allowing for efficient analysis of models.

  2. Shape memory alloy thaw sensors

    Science.gov (United States)

    Shahinpoor, Mohsen (Albuquerque, NM); Martinez, David R. (Albuquerque, NM)

    1998-01-01

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

  3. Electrorefining studies on uranium alloys

    International Nuclear Information System (INIS)

    Molten salt electrorefining finds application as a suitable reprocessing method for irradiated U-Pu-Zr alloy fuel. Electrorefining experiments were carried out on alloys containing U, Zr, Ce and Pd. The decontamination factors obtained in these experiments are discussed in comparison with the ones predicted by the thermodynamic computations and existing literature data. (author). 6 refs., 1 fig., 3 tabs

  4. 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.

  5. Forming of fine-grained superplastic structures of two types of precipitation in austenite alloys on Ni-Cr and Co-Ni basis

    International Nuclear Information System (INIS)

    Full text: Authors of the submitted work carry out research of influence of a high degree of cold rolling deformation on structural-phase transformations at the subsequent ageing industrial dispersion-hardening alloys on Ni-Cr and Mo-Ni basis. By optical metallography and transmission electronic microscopy methods the parameters the dislocations' structure forming by different degrees of deformation and structure formed during precipitation from a solid solution at ageing of were established. The data of researches of thin structure are compared to the data on mechanical properties of a material. Using features of preliminary cold deformation at ageing alloys, it is possible to offer phase and structural transformations easily sold ways of reception of a ultra fine-grained microstructure in alloys 36NKhTYu, 40KhNYu, 67KN5B that will allow to realize in the given alloys transition in a superplastic condition. In this connection acknowledgement of superplastic properties of the given alloys with the various mechanical and thermal processing (MTP) is actual. MTP of alloys 36NKhTYu, 40KhNYu, 67KN5B (industrial dispersion-hardening heat resisting alloys of standard structure) included training on a single-phase solid solution, flattering and ageing in vacuum is no worse 1 Pa. Research of thin structure was carried out on transmission electronic microscope JEM-100 CX (foil). For studying the common character of structure used an optical microscope 'Neophot 21', and diffractometer DRON -3 for studying phase structure of samples. High-temperature test of samples of an alloys 40KhNYu and 67KN5B on a stretching carried out on installation 1246P-2/2500 in an interval of temperatures 1153-1323 K in vacuum with residual pressure not worse 10-2 Pa. Mechanical tests included one axis static tension measurement of breaking point ?b, relative fluid limit ?02, relative lengthening till gap ? (%). The fractography a cross break studied on electron-zoned microanalyzer SUPERPROBE 733 JEOL in a raster mode secondary electrons. Result of the analysis of experimental data are the following conclusions: 1. Metallography and electron-microscopic researches it is established, that in an alloy 36NKhTYu to a condition of superplasticity there corresponds a special microstructure from elementary cells of cellular precipitation. The size and volume fraction in an alloy of these cells is determined by time of annealing at the constant temperature. A superplastic condition in an alloy 40KhNYu and 67KH5B at the structure provides a micro duplex. 2. The concrete modes of mechanical-thermal processing including a high degree of deformation and the subsequent ageing are recommended, allowing to receive fine-grained structures with high properties of plasticity in alloys 36NKhTYu, 40KhNYu, 67KN5B. 3. One axis the stretching of samples of an alloy 40KhNYu and 67KN5B at high temperature has shown that preliminary processing, namely: training 1323 K (5 min) + flattering with ?=90 % provides occurrence of a superplastic condition of an alloy in an interval of deformation's speeds 10-4-10-2 s-1 and in an interval of temperatures 1153-1323 K (40KhNYu) and training 1423 K (10 min) + flattering with ?=90 % provides occurrence of a superplastic condition of an alloy in an interval of deformation's speeds 0.8·10-3 s-1 and the temperature 1143 K (67KN5B)

  6. High performance alloy electroforming

    Science.gov (United States)

    Malone, G. A.; Winkelman, D. M.

    1989-01-01

    Electroformed copper and nickel are used in structural applications for advanced propellant combustion chambers. An improved process has been developed by Bell Aerospace Textron, Inc. wherein electroformed nickel-manganese alloy has demonstrated superior mechanical and thermal stability when compared to previously reported deposits from known nickel plating processes. Solution chemistry and parametric operating procedures are now established and material property data is established for deposition of thick, large complex shapes such as the Space Shuttle Main Engine. The critical operating variables are those governing the ratio of codeposited nickel and manganese. The deposition uniformity which in turn affects the manganese concentration distribution is affected by solution resistance and geometric effects as well as solution agitation. The manganese concentration in the deposit must be between 2000 and 3000 ppm for optimum physical properties to be realized. The study also includes data regarding deposition procedures for achieving excellent bond strength at an interface with copper, nickel-manganese or INCONEL 718. Applications for this electroformed material include fabrication of complex or re-entry shapes which would be difficult or impossible to form from high strength alloys such as INCONEL 718.

  7. Stainless-Steel-Gadolinium Alloys

    International Nuclear Information System (INIS)

    Because of the excellent corrosion resistance of stainless steels and the interest in gadolinium as a poison material, alloys of the two compounds were studied.Gadolinium was alloyed with AISE 304-type and chromium-type stainless steels; and then phase relationships, fabricability and properties were studied. The melting points of minor phases in alloys containing low percentages of gadolinium were noted to have a large effect on the structures resulting from equilibrating treatments and fabricability of the steels. When gadolinium was alloyed with the chromium-nickel-type steel, two minor phases, Fe9Gd and Ni7Gd, were observed to melt at 1080°C, which limited the heat treatment and fabrication temperatures. Alloys with up to 5 wt.% gadolinium were successfully fabricated, and mechanical and corrosion properties were determined. No changes in the mechanical properties or resistance to hot-water corrosion of the steel were observed on alloying with up to about 3 wt.% gadolinium. Because of fabrication temperature limitations placed on chromium-nickel steels by the melting point of the minor phases, the effects of gadolinium on chromium steels were studied. Only one minor phase that melted at 1320°C was noted on investigation of the 10 wt. % gadolinium isopleth in the chromium-iron-gadolinium alloy system. This property would enable one to equilibrate and fabricate these gadolinium steels at normally used temperatures. (author)

  8. Microstructural studies on Alloy 693

    Energy Technology Data Exchange (ETDEWEB)

    Halder, R.; Dutta, R.S. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sengupta, P., E-mail: praneshsengupta@gmail.com [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Samajdar, I. [Dept. of Metall. Engg. and Mater. Sci., Indian Institute of Technology Bombay, Mumbai 400 072 (India); Dey, G.K. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2014-10-15

    Superalloy 693, is a newly identified ‘high-temperature corrosion resistant alloy’. Present study focuses on microstructure and mechanical properties of the alloy prepared by double ‘vacuum melting’ route. In general, the alloy contains ordered Ni{sub 3}Al precipitates distributed within austenitic matrix. M{sub 6}C primary carbide, M{sub 23}C{sub 6} type secondary carbide and NbC particles are also found to be present. Heat treatment of the alloy at 1373 K for 30 min followed by water quenching (WQ) brings about a microstructure that is free from secondary carbides and Ni{sub 3}Al type precipitates but contains primary carbides. Tensile property of Alloy 693 materials was measured with as received and solution annealed (1323 K, 60 min, WQ) and (1373 K, 30 min, WQ) conditions. Yield strength, ultimate tensile strength (UTS) and hardness of the alloy are found to drop with annealing. It is noted that in annealed condition, considerable cold working of the alloy can be performed.

  9. Dendritic Alloy Solidification Experiment (DASE)

    Science.gov (United States)

    Beckermann, C.; Karma, A.; Steinbach, I.; deGroh, H. C., III

    2001-01-01

    A space experiment, and supporting ground-based research, is proposed to study the microstructural evolution in free dendritic growth from a supercooled melt of the transparent model alloy succinonitrile-acetone (SCN-ACE). The research is relevant to equiaxed solidification of metal alloy castings. The microgravity experiment will establish a benchmark for testing of equiaxed dendritic growth theories, scaling laws, and models in the presence of purely diffusive, coupled heat and solute transport, without the complicating influences of melt convection. The specific objectives are to: determine the selection of the dendrite tip operating state, i.e. the growth velocity and tip radius, for free dendritic growth of succinonitrile-acetone alloys; determine the growth morphology and sidebranching behavior for freely grown alloy dendrites; determine the effects of the thermal/solutal interactions in the growth of an assemblage of equiaxed alloy crystals; determine the effects of melt convection on the free growth of alloy dendrites; measure the surface tension anisotropy strength of succinon itrile -acetone alloys establish a theoretical and modeling framework for the experiments. Microgravity experiments on equiaxed dendritic growth of alloy dendrites have not been performed in the past. The proposed experiment builds on the Isothermal Dendritic Growth Experiment (IDGE) of Glicksman and coworkers, which focused on the steady growth of a single crystal from pure supercooled melts (succinonitrile and pivalic acid). It also extends the Equiaxed Dendritic Solidification Experiment (EDSE) of the present investigators, which is concerned with the interactions and transients arising in the growth of an assemblage of equiaxed crystals (succinonitrile). However, these experiments with pure substances are not able to address the issues related to coupled heat and solute transport in growth of alloy dendrites.

  10. Competition between elements during mechanical alloying in an octonary multi-principal-element alloy system

    International Nuclear Information System (INIS)

    The competition between the constituent elements of the Cu0.5NiAlCoCrFeTiMo alloy system during mechanical alloying was investigated and ranked with their alloying rates in getting alloyed in the mixture. By using XRD analysis, EDS mapping, extended X-ray absorption fine structure technique, and synchrotron radiation diffraction, the alloying sequence for the present alloy system is determined as Al ? Cu ? Co ? Ni ? Fe ? Ti ? Cr ? Mo in the order of decreasing alloying rate. The alloying rate is found to correlate best with the melting point of the elements among metallurgical factors. The mechanism for this correlation is explained through the effect of melting point on solid-state diffusion and mechanical disintegration which are critical for the final alloying. This finding is valuable in predicting the alloying sequence of elements, and thus the phase evolution in multi-component alloys during mechanical alloying.

  11. Alloying and Casting Furnace for Shape Memory Alloys Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The concept in the proposed project is to create a melting, alloying and casting furnace for the processing titanium based SMA using cold crucible techniques. The...

  12. Role of alloying element in superplastic deformation of aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Furushiro, N. [Osaka Univ., Suita (Japan). International Student Center; Dept. of Materials Science and Engineering, Osaka Univ., Suita (Japan); Umakoshi, Y. [Dept. of Materials Science and Engineering, Osaka Univ., Suita (Japan); Warashina, K. [Osaka Univ. (Japan)

    2001-07-01

    It is well known that metallic materials which exhibit typical superplasticity are generally not pure metals but alloys. The alloying elements exist in different phases or as solute atoms. Role of the solute atoms during the deformation has been a great interest not only in making clear the deformation mechanism but also in designing new materials. The objective of the present study is to examine the role of copper addition in Al-Cu-Zr alloys. Alloys of Al-Cu-0.3%Zr were prepared for the specimens, copper contents of which were 0, 0.5, 0.9, 1.6, 3.1, 4.9 and 6.4%. Tensile specimens were cut from the sheets warm-rolled at 623 K. Tensile tests were carried out at 623-773 K and at 1.7 x 10{sup -4}-1.7 x 10{sup -2} s{sup -1}. Microstructures were observed on the specimens of deformed or non-deformed condition by TEM. In all specimens, Zr atoms are found to be precipitated as fine particles of metastable Al{sub 3}Zr. The large elongations were obtained in specimens including particles of the {theta} (Al{sub 2}Cu) phase. Even in alloys of single phase (solid solution), the elongation increased with an increases of copper content. That implies that solute copper also has a significant effect on superplasticity. Deformation characteristics of the Al-x%Cu-0.3%Zr alloys considerably depend on the copper content. That means the existence of the optimum copper content for superplasticity of the alloys. The role of solute copper is to increase flow stress of the matrix, while the fine particles of the {theta} phase are useful to both form and hold the fine grain structure. Using the present results, the minimum misorientation at grain boundary sliding in superplastic aluminum alloys will be also discussed. (orig.)

  13. Metallic alloy stability studies

    Science.gov (United States)

    Firth, G. C.

    1983-01-01

    The dimensional stability of candidate cryogenic wind tunnel model materials was investigated. Flat specimens of candidate materials were fabricated and cryo-cycled to assess relative dimensional stability. Existing 2-dimensional airfoil models as well as models in various stages of manufacture were also cryo-cycled. The tests indicate that 18 Ni maraging steel offers the greatest dimensional stability and that PH 13-8 Mo stainless steel is the most stable of the stainless steels. Dimensional stability is influenced primarily by metallurgical transformations (austenitic to martensitic) and manufacturing-induced stresses. These factors can be minimized by utilization of stable alloys, refinement of existing manufacturing techniques, and incorporation of new manufacturing technologies.

  14. Corrosion resistant austenitic alloy

    International Nuclear Information System (INIS)

    An austenitic stainless corrosion resistant alloy and articles made therefrom having good resistance to pitting and crevice corrosion in oxidizing chloride-bearing media combined with resistance to general corrosion and to intergranular corrosion in oxidizing media containing C, Mn, Si, P, S, Cr, Ni, Mo, Cu, N, B, Ce, La, Nb, Ti and the balance iron. The amount of nitrogen is not greater than that which can be retained in solution. When present niobium plus titanium ranges upward from a minimum which is sufficient to combine stoichiometrically with the amount of carbon present in excess of 0.025 w/o. In this composition the elements chromium, nickel, molybdenum and copper are balanced so that the value of Correlation I is equal to or less than 1.6021 and that of Correlation II is equal to or less than 5

  15. Smart interfacial bonding alloys

    Energy Technology Data Exchange (ETDEWEB)

    R. Q. Hwang; J. C. Hamilton; J. E. Houston

    1999-04-01

    The goal of this LDRD was to explore the use of the newly discovered strain-stabilized 2-D interfacial alloys as smart interface bonding alloys (SIBA). These materials will be used as templates for the heteroepitaxial growth of metallic thin films. SIBA are formed by two metallic components which mix at an interface to relieve strain and prevent dislocations from forming in subsequent thin film growth. The composition of the SIBA is determined locally by the amount of strain, and therefore can react smartly to areas of the highest strain to relieve dislocations. In this way, SIBA can be used to tailor the dislocation structure of thin films. This project included growth, characterization and modeling of films grown using SIBA templates. Characterization will include atomic imaging of the dislocations structure, measurement of the mechanical properties of the film using interface force microscopy (IFM) and the nanoindenter, and measurement of the electronic structure of the SIBA with synchrotron photoemission. Resistance of films to sulfidation and oxidation will also be examined. The Paragon parallel processing computer will be used to calculate the structure of the SIBA and thin films in order to develop ability to predict and tailor SIBA and thin film behavior. This work will lead to the possible development of a new class of thin film materials with properties tailored by varying the composition of the SIBA, serving as a buffer layer to relieve the strain between the substrate and the thin film. Such films will have improved mechanical and corrosion resistance allowing application as protective barriers for weapons applications. They will also exhibit enhanced electrical conductivity and reduced electromigration making them particularly suitable for application as interconnects and other electronic needs.

  16. First principles thermodynamics of alloys

    OpenAIRE

    Ducastelle, F.

    1993-01-01

    We present a brief report on the methods of solid state physics (electronic structure, statistical thermodynamics) that allow us to discuss the phase stability of alloys and to determine their phase diagrams.

  17. Emissivity measurements on aeronautical alloys

    Energy Technology Data Exchange (ETDEWEB)

    Campo, L. del, E-mail: leire.del-campo@cnrs-orleans.f [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Perez-Saez, R.B., E-mail: raul.perez@ehu.e [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao (Spain); Gonzalez-Fernandez, L. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Esquisabel, X.; Fernandez, I. [Industria de Turbo Propulsores, S.A., Planta de Zamudio, Edificio 300, 48170 Zamudio, Bizkaia (Spain); Gonzalez-Martin, P. [Industria de Turbo Propulsores, S.A., Parque empresarial San Fernando, Avda. Castilla 2, 28830 San Fernando de Henares, Madrid (Spain); Tello, M.J. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao (Spain)

    2010-01-21

    The emissivity of three Ni and Co based aeronautical alloys is analyzed in this paper. These alloys are employed in high temperature environments whenever good corrosion resistance, high temperature resistance and high strength are essential. Thus, apart from the aeronautical industry, these alloys are also used in other technological applications, as for example, aerospace, nuclear reactors, and tooling. The results in this paper extend the emissivity data for these alloys available in the literature. Emissivity dependence on the radiation wavelength (2-22 {mu}m), sample temperature (200-650 {sup o}C) and emission angle (0-85{sup o}) has been investigated. In addition, the effect of surface finish and oxidation has also been taken into consideration. The data in this paper have several applications, as temperature measurement of a target by pyrometry, low observability of airplanes and thermal radiation heat transfer simulation in airplane nozzles or furnaces.

  18. Emissivity measurements on aeronautical alloys

    International Nuclear Information System (INIS)

    The emissivity of three Ni and Co based aeronautical alloys is analyzed in this paper. These alloys are employed in high temperature environments whenever good corrosion resistance, high temperature resistance and high strength are essential. Thus, apart from the aeronautical industry, these alloys are also used in other technological applications, as for example, aerospace, nuclear reactors, and tooling. The results in this paper extend the emissivity data for these alloys available in the literature. Emissivity dependence on the radiation wavelength (2-22 ?m), sample temperature (200-650 oC) and emission angle (0-85o) has been investigated. In addition, the effect of surface finish and oxidation has also been taken into consideration. The data in this paper have several applications, as temperature measurement of a target by pyrometry, low observability of airplanes and thermal radiation heat transfer simulation in airplane nozzles or furnaces.

  19. Nanocrystalline Alloys with Enhanced Properties

    International Science & Technology Center (ISTC)

    The Creation of Scientific Basis for Development of Technology for Manufacturing Sheets and Strips of Fe- and Cu-based Alloys with Nanocrystalline Structure with Enhanced Strength, Electric Conductivity and Damping Properties

  20. Hollow Blades from Titanium Alloys

    International Science & Technology Center (ISTC)

    Development of Elements of the Technology Producing Hollow Blades from Submicrocrystalline Titanium Alloys by Combining Molding and Diffusion Welding under Low-Temperature Superplasticity, Including Non-Destructive Quality Control over Parts Produced

  1. [MRO] Oligocrystalline Shape Memory Alloys

    OpenAIRE

    Chen, Ying; Schuh, Christopher A.; Ueland, Stian Melhus

    2011-01-01

    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 juncti...

  2. Superplastic properties of magnesium alloys

    OpenAIRE

    M. Greger; R. Kocich; L. ?ížek

    2007-01-01

    Purpose: The paper summarises results of experiments aimed at development of structure of modified Mg-Al-Zn alloys at hot deformation.Design/methodology/approach: Methods ARB and ECAP were used in the described experiment. It was proved that hardly forming materials could achieve very high plastics properties.Findings: After making plastics deformation, the using materials of alloys AZ61 and AZ91 analysed superplastics behaviour, it was certified by obtaining results, when ductility to ruptu...

  3. Ni{sub 3}Al aluminide alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.T.

    1993-10-01

    This paper provides a brief review of the recent progress in research and development of Ni{sub 3}Al and its alloys. Emphasis has been placed on understanding low ductility and brittle fracture of Ni{sub 3}Al alloys at ambient and elevated temperatures. Recent studies have resulted in identifying both intrinsic and extrinsic factors governing the fracture behavior of Ni{sub 3}Al alloys. Parallel efforts on alloy design using physical metallurgy principles have led to properties for structural use. Industrial interest in these alloys is high, and examples of industrial involvement in processing and utilization of these alloys are briefly mentioned.

  4. Mechanical characterization of superalloys for space reactors

    International Nuclear Information System (INIS)

    The aim of this work is the selection of structural materials that can be used in the temperature range 600-9000C for a gas cooled space reactor producing electricity. Superalloys fit best the temperature range required. Five nickel base alloys are chosen for their good mechanical behaviour: HAYNES 230, HASTELLOY S, HASTELLOY X, HASTELLOY XR and PYRAD 38D. Metallography, tensile and hardness tests are realized. Sample contraction is evidenced for some creep tests, under low stress: 20MPa at 8000C, on HAYNES 230 and HASTELLOY X, probably related to the structural evolution of these materials corresponding to a decrease of the crystal parameter

  5. Characterizing alloy additions to high nitrogen steels

    Energy Technology Data Exchange (ETDEWEB)

    Rawers, James C.; Tylczak, Joseph H.; Blankenship, D.; Bullard, Sophie J.

    2003-01-01

    Numerous articles of individual high nitrogen stainless steel compositions or alloys with near identical alloy compositions have been published characterizing the properties the alloy or the improvement which an individual element contributes to the base alloy's properties. In this study a series of high nitrogen steels alloys were prepared with the intent of characterizing the advantages and limitations of different alloy chemistry on the base alloy's material properties such as: microstructure, mechanical properties, environmental interactions (corrosion and oxidation), and wear. A base composition of Fe-15Cr-15 Mn was chosen. Alloys of similar basic compositions are austenitic and often used as a starting composition as a substitute or replacements for Fe-Cr-Ni stainless steel alloys. Mn is less expensive than Ni, is a strong austenizer, enhances nitrogen solubility, and has no allergenic effects. To this base alloy composition additions of C, N, Si, Mo, and Nb was added. Nitrogen (and carbon) alloys as interstitials and have been shown to enhance strength and reduce corrosion. Niobium (or similar elements) is often added to produce intergranular carbide precipitates that further enhance strength. Molybdenum and silicon are added to improve corrosion-oxidation properties. This study was designed to evaluate the action and interaction of these different alloys and suggest what alloys compositions are best used under different engineering requirements. The results of the experimental alloys are compared with that of two experimental higher-nitrogen commercial alloys steels with further alloy addition of Ni and Cu were also studied. Alloy evaluation included: (1) microstructure: optical, SEM, and X-ray diffraction, (2) mechanical properties: yield, tensile, elongation, hardness (room temperature and hot), and energy to failure, (3) oxidation and corrosion, and (4) abrasive wear: scratch, pin-on-drum, and pin-on-disk.

  6. Cu-Mo alloys obtained by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo, J.; Martinez, V.; Ordonez, S. [Dept. de Ingenieria Metalurgica, Univ. de Santiago de Chile, Santiago (Chile)

    2001-07-01

    In the present work the production and microstructural evolution of Cu based alloys, with amounts of Mo of 3, 5 y 10 wt%, obtained by mechanical alloying (MA) were studied. The MA process was carried out using a Spex 8000 high-energy ball mill during different milling times. The process was followed through X-ray diffraction and scanning electron microscopy. Crystallite sizes of the powder mechanically alloyed were calculated from X-ray diffraction patterns by Scherrer's formula and the results showed an exponential decrease with a minimum value of 12 nm for 50 hours of milling time. The Vickers hardness (HV) of mechanically alloyed powder increased with milling time and the Mo content reaching a value of 634 HV for Cu-20wt% Mo and 50 hours of milling time. The amount of Mo dissolved in the copper solid solution was obtained from the lattice parameter by means of Vegard's law. The Cu-20wt% Mo alloy reached the maximum value for 50 hours (0.36247 nm), for Cu-3wt% Mo and Cu-5wt% Mo the maximum value was obtained for 10 hours. (orig.)

  7. Imprinting bulk amorphous alloy at room temperature

    Science.gov (United States)

    Kim, Song-Yi; Park, Eun-Soo; Ott, Ryan T.; Lograsso, Thomas A.; Huh, Moo-Young; Kim, Do-Hyang; Eckert, Jürgen; Lee, Min-Ha

    2015-11-01

    We present investigations on the plastic deformation behavior of a brittle bulk amorphous alloy by simple uniaxial compressive loading at room temperature. A patterning is possible by cold-plastic forming of the typically brittle Hf-based bulk amorphous alloy through controlling homogenous flow without the need for thermal energy or shaping at elevated temperatures. The experimental evidence suggests that there is an inconsistency between macroscopic plasticity and deformability of an amorphous alloy. Moreover, imprinting of specific geometrical features on Cu foil and Zr-based metallic glass is represented by using the patterned bulk amorphous alloy as a die. These results demonstrate the ability of amorphous alloys or metallic glasses to precisely replicate patterning features onto both conventional metals and the other amorphous alloys. Our work presents an avenue for avoiding the embrittlement of amorphous alloys associated with thermoplastic forming and yields new insight the forming application of bulk amorphous alloys at room temperature without using heat treatment.

  8. Mechanical alloying, microstructure and properties of Nb-16Si alloy

    International Nuclear Information System (INIS)

    Nb-16 at.% Si bulk alloys were prepared by uniaxial hot pressing from mechanically alloyed powder mixtures. It is shown that the addition of appropriate absolute ethyl alcohol significantly restrained the agglomeration of particles and accelerated the milling process. Moreover, besides the solid solution of Si into Nb lattice, significant iron contamination dissolved into Nb to develop another Nb solid solution after a long milling time. Sintering results indicate that, with sintering temperature increasing from 1200 to 1500 oC, densities and mechanical properties of sintered alloys increased and the morphology of constituent phases (niobium solid solution, Nb5Si3 and Nb3Si in micron dimension) changed from irregular shape to nearly equiaxed one. However, as for the material hot pressed at 1600 oC, the microstructure became coarser and the properties were not improved because of the weakening of fine-grain contribution.

  9. Shape memory alloys. Ultralow-fatigue shape memory alloy films.

    Science.gov (United States)

    Chluba, Christoph; Ge, Wenwei; Lima de Miranda, Rodrigo; Strobel, Julian; Kienle, Lorenz; Quandt, Eckhard; Wuttig, Manfred

    2015-05-29

    Functional shape memory alloys need to operate reversibly and repeatedly. Quantitative measures of reversibility include the relative volume change of the participating phases and compatibility matrices for twinning. But no similar argument is known for repeatability. This is especially crucial for many future applications, such as artificial heart valves or elastocaloric cooling, in which more than 10 million transformation cycles will be required. We report on the discovery of an ultralow-fatigue shape memory alloy film system based on TiNiCu that allows at least 10 million transformation cycles. We found that these films contain Ti2Cu precipitates embedded in the base alloy that serve as sentinels to ensure complete and reproducible transformation in the course of each memory cycle. PMID:26023135

  10. Rare-Earth-Rich Alloys

    International Nuclear Information System (INIS)

    The rare earth metals with high thermal-neutron capture cross-sections are of interest for control of power-producing reactors; however, they are susceptible to corrosion. On the premise that non-rare earth metals may be alloyed with dysprosium, erbium, gadolinium and samarium, thus improving their properties, the effects of selected alloying additions on the rare earths were studied. The solubilities of the non-rare earth metals, zirconium, vanadium, chromium, iron, nickel, copper, aluminium and silicon, in dysprosium, erbium, gadolinium and samarium and their effects on the melting points, solid state transformations and corrosion properties were studied. -Phase diagrams were prepared up to the first rare earth-rich compound or eutectic, whichever occurred first. On completion of that portion of the work, alloys were made, heat-treated to yield maximum solid solubility of the non-rare earth alloying addition, and oxidation- and corrosion-tested. No improvement of the rare earth metals to oxidation resistance in the atmosphere was observed on alloying; in fact, most additions proved to be deleterious. Aluminium greatly improved the hot-Water corrosion resistance of the rare earths tested; other non-rare earth metal additions improved the resistance to a lesser degree. (author)

  11. Dispersion strengthening of niobium alloys

    International Nuclear Information System (INIS)

    This paper reports on this investigation that was conducted in order to identify stable dispersions in niobium alloys, fabricate material through a rapid solidification approach and characterize precipitate formation. A thermodynamic approach was utilized to select candidate dispersions for evaluation. Arc melted and splat quenched alloys were evaluated by micro-harness measurements. An indirect assessment of particle stability is introduced, by means of which a coarsening parameter was determined for each candidate precipitate at 1400 degrees C (2552 degrees F). Microscopic examinations of the more stable alloys were made via optical and thin foil TEM analyses. The strongest alloys examined were those with precipitates of the refractory metals Zr and Hf, as either nitrides or borides, and an alloy containing TiN. These precipitates were found to be in either a plate or needlelike morphology, and were uniformly distributed throughout the matrix. Large blocky oxides of the refractory elements were observed in the grain boundaries, along with discrete particles of niobium nitrides or borides

  12. CORROSION RESISTANCE OF ALUMINUM-LITHIUM ALLOYS

    OpenAIRE

    Lin, F; Moji, Y.; Quist, W.; Badger, D.

    1987-01-01

    The effects of corrosive environments on aluminum-lithium-copper-(magnesium) alloys have been studied as they relate to the commercial airplane industry. It has been found that, in general, the alloys 2090 and 2091 exhibit equal or improved corrosion performance compared to the 2024 and 7075 alloys they are likely to replace. Cladding and coating systems have been shown to compare favorably with conventional alloys.

  13. Design optimization of shape memory alloy structures:

    OpenAIRE

    Langelaar, M.

    2006-01-01

    This thesis explores the possibilities of design optimization techniques for designing shape memory alloy structures. Shape memory alloys are materials which, after deformation, can recover their initial shape when heated. This effect can be used for actuation. Emerging applications for shape memory alloys are e.g. miniaturized medical instruments with embedded actuation, as well as microsystem components. However, designing effective shape memory alloy structures is a challenging task, due t...

  14. Boriding of titanium-molybdenum alloys

    International Nuclear Information System (INIS)

    The interaction of the Ti-Mo system alloys with boron in the 1200-1450 deg C temperature range is investigated. It is shown that the velocity of interaction is determined by the alloy compocition. The velocity of boride phase growth in 10-30 at.% Mo alloys is considerably lower than in pure titanium or molybdenum. The said alloys are shown to be stable in boron containing media at high temperature

  15. Effect of copper alloying on the electrochemical behaviour of passive Al-2Li alloy

    International Nuclear Information System (INIS)

    Effect of copper alloying 13 mas.% on the regularities of corrosion behaviour of Al-2Li alloy in 0.5M NaCl solution in a passive state is studied. Negative effect of alloying on corrosion resistance under these conditions is ascertained. A notable role of oxygen reduction cathode reactions and hydrogen release in corrosion resistance of an alloy alloyed with copper is demonstrated. Refs. 13, figs. 4

  16. Materials data handbook, aluminum alloy 6061

    Science.gov (United States)

    Sessler, J.; Weiss, V.

    1969-01-01

    Comprehensive compilation of technical data on aluminum alloy 6061 is presented in handbook form. The text includes data on the properties of the alloy at cryogenic, ambient, and elevated temperatures and other pertinent information required for the design and fabrication of components and equipment utilizing this alloy.

  17. Palladium alloys with americium and curium

    International Nuclear Information System (INIS)

    The investigation results of palladium alloys containing up to 15 % of americium and curium are presented and their corresponding parts of the phase diagrams are obtained. A tendency to alloying additive depletion on the surface of palladium solid solution during mechanical-thermal treatment of the investigated alloys was revealed. 22 refs.; 12 figs.; 4 tabs

  18. Nonequilibrium segregation in concentrated alloys under irradiation

    International Nuclear Information System (INIS)

    Radiation-induced segregation in concentrated alloys was investigated using a model based on the concept of relative differences in the effective diffusion rates of the alloy components via the vacancy and interstitial mechanisms. Numerical results were obtained for various irradiation conditions and alloy systems and compared with experimental data

  19. Magnesium and related low alloys

    International Nuclear Information System (INIS)

    In the first part the authors examine the comparative corrosion of commercial magnesium, of a magnesium-zirconium alloy (0,4 per cent ? Zr ? 0,7 per cent) of a ternary magnesium-zinc-zirconium alloy (0,8 per cent ? Zn ? 1,2 per cent) and of english 'Magnox type' alloys, in dry carbon dioxide-free air, in damp carbon dioxide-free air, and in dry and damp carbon dioxide, at temperatures from 300 to 600 deg. C. In the second part the structural stability of these materials is studied after annealings, of 10 to 1000 hours at 300 to 450 deg. C. Variations in grain after these heat treatments and mechanical stretching properties at room temperature are presented. Finally various creep rate and life time diagrams are given for these materials, for temperatures ranging from 300 to 450 deg. C. (author)

  20. Copper-Refractory Metal Alloys

    Science.gov (United States)

    Verhoeven, J. D.; Schmidt, F. A.; Gibson, E. D.; Spitzig, W. A.

    1986-09-01

    This research shows that Cu-V, Cu-Nb and Cu-Ta castings may be prepared by consumable are casting. The resulting alloys, consisting of refractory metal dendrites in a Cu matrix, are quite ductile and, when mechanically reduced by large reduction in areas, produce an aligned composite material. The strength, strength/electrical conductivity, superconductivity and surface properties of these composites are reviewed. The scale-up potential of consumable are casting for producing these three alloys as well as Cu-Mo, Cu-Cr and Cu-Fe is also discussed.

  1. Alloy 718 for Oilfield Applications

    Science.gov (United States)

    deBarbadillo, John J.; Mannan, Sarwan K.

    2012-02-01

    Alloy 718 (UNS N07718) was developed for use in aircraft gas turbine engines, but its unique combination of room-temperature strength and aqueous corrosion resistance made it a candidate for oilfield fasteners, valves, drill tools, and completion equipment. As well environments became more severe, stress corrosion and hydrogen embrittlement failures in production equipment drove the evolution of the composition and microstructure that distinguish today's oilfield-grade 718 from aerospace grades. This paper reviews the development of the grade and its applications and describes some of its unique characteristics, testing, and manufacturing methods as well as newer alloys designed for high-pressure high-temperature (HPHT) conditions.

  2. Theoretical studies of metallic alloys

    International Nuclear Information System (INIS)

    A new method to predict and understand the structure and phase stability of solid-solution alloys from a knowledge only of the atomic numbers of the constituent atoms is being developed. The coherent potential approximation will be used to obtain the electronic contribution to the energy and the Monte Carlo method of statistical mechanics will be used for the thermodynamic part of the calculation. An improved coherent potential approximation will be developed by combining the standard approach with the quadratic KKR (QKKR) band theory method. This will make it easier to predict the properties of alloys from first principles. The QKKR method will be developed further

  3. Hydrogen effects in aluminum alloys

    International Nuclear Information System (INIS)

    The permeability of six commercial aluminum alloys to deuterium and tritium was determined by several techniques. Surface films inhibited permeation under most conditions; however, contact with lithium deuteride during the tests minimized the surface effects. Under these conditions phi/sub D2/ = 1.9 x 10-2 exp (--22,400/RT) cc (NTP)atm/sup --1/2/ s-1cm-1. The six alloys were also tested before, during, and after exposure to high pressure hydrogen, and no hydrogen-induced effects on the tensile properties were observed

  4. An introduction to surface alloying of metals

    CERN Document Server

    Hosmani, Santosh S; Goyal, Rajendra Kumar

    2014-01-01

    An Introduction to Surface Alloying of Metals aims to serve as a primer to the basic aspects of surface alloying of metals. The book serves to elucidate fundamentals of surface modification and their engineering applications. The book starts with basics of surface alloying and goes on to cover key surface alloying methods, such as carburizing, nitriding, chromizing, duplex treatment, and the characterization of surface layers. The book will prove useful to students at both the undergraduate and graduate levels, as also to researchers and practitioners looking for a quick introduction to surface alloying.

  5. Corrosion evaluation of alternate nuclear steam generator tubing materials

    International Nuclear Information System (INIS)

    Several materials were evaluated for use in nuclear steam generators (NSG). These materials were exposed to corrosive conditions representative of those found in nuclear steam generators. The materials evaluated were gold, titanium, tantalum, niobium, Hastelloy C-276, Hastelloy G. Nickel 200, nickel-base Alloy 625, and heat-tracked nickel-base Alloy 600. The test environments simulated acid pitting attack, caustic stress corrosion cracking and reduced sulfur attack. In the pitting environment, the monolithic materials did well, however Nickel 200, nickel-base Alloy 600 and Hastelloy G3 did poorly. The remaining alloys, nickel-base Alloy 625 and Hastelloy C-276 were relatively unaffected in the pitting environment. Tantalum, titanium, niobium, nickel-base Alloy 625 performed poorly in the environment designed to evaluate resistance to caustic cracking. Nickel-base Alloy 600 (stress-relieved), Hastelloy C-276, Hasteloy G-3 and Nickel 200 compared fair to good in the caustic sodium. The gold was unaffected in the hot caustic solution. In the environment selected to represent a reduced sulfur environment, nickel-base Alloy 625 and Hastelloy C-276 exhibited considerable resistance. The nickel-base Alloy 600 was attacked within a relatively short period of time

  6. Passive Corrosion Behavior of Alloy 22

    International Nuclear Information System (INIS)

    Alloy 22 (NO6022) was designed to stand the most aggressive industrial applications, including both reducing and oxidizing acids. Even in the most aggressive environments, if the temperature is lower than 150 F (66 C) Alloy 22 would remain in the passive state having particularly low corrosion rates. In multi-ionic solutions that may simulate the behavior of concentrated ground water, even at near boiling temperatures, the corrosion rate of Alloy 22 is only a few nano-meters per year because the alloy is in the complete passive state. The corrosion rate of passive Alloy 22 decreases as the time increases. Immersion corrosion testing also show that the newer generation of Ni-Cr-Mo alloys may offer a better corrosion resistance than Alloy 22 only in some highly aggressive conditions such as in hot acids

  7. Passive Corrosion Behavior of Alloy 22

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B; Payer, J H

    2006-01-10

    Alloy 22 (N06022) was designed to stand the most aggressive industrial applications, including both reducing and oxidizing acids. Even in the most aggressive environments, if the temperature is lower than 150 F (66 C) Alloy 22 would remain in the passive state having particularly low corrosion rates. In multi-ionic solutions that may simulate the behavior of concentrated ground water, even at near boiling temperatures, the corrosion rate of Alloy 22 is only a few nanometers per year because the alloy is in the complete passive state. The corrosion rate of passive Alloy 22 decreases as the time increases. Immersion corrosion testing also show that the newer generation of Ni-Cr-Mo alloys may offer a better corrosion resistance than Alloy 22 only in some highly aggressive conditions such as in hot acids.

  8. Passive Corrosion Behavior of Alloy 22

    Energy Technology Data Exchange (ETDEWEB)

    R.B. Rebak; J.H. Payer

    2006-01-20

    Alloy 22 (NO6022) was designed to stand the most aggressive industrial applications, including both reducing and oxidizing acids. Even in the most aggressive environments, if the temperature is lower than 150 F (66 C) Alloy 22 would remain in the passive state having particularly low corrosion rates. In multi-ionic solutions that may simulate the behavior of concentrated ground water, even at near boiling temperatures, the corrosion rate of Alloy 22 is only a few nano-meters per year because the alloy is in the complete passive state. The corrosion rate of passive Alloy 22 decreases as the time increases. Immersion corrosion testing also show that the newer generation of Ni-Cr-Mo alloys may offer a better corrosion resistance than Alloy 22 only in some highly aggressive conditions such as in hot acids.

  9. Environmental fatigue in aluminum-lithium alloys

    Science.gov (United States)

    Piascik, Robert S.

    1992-01-01

    Aluminum-lithium alloys exhibit similar environmental fatigue crack growth characteristics compared to conventional 2000 series alloys and are more resistant to environmental fatigue compared to 7000 series alloys. The superior fatigue crack growth behavior of Al-Li alloys 2090, 2091, 8090, and 8091 is due to crack closure caused by tortuous crack path morphology and crack surface corrosion products. At high R and reduced closure, chemical environment effects are pronounced resulting in accelerated near threshold da/dN. The beneficial effects of crack closure are minimized for small cracks resulting in rapid growth rates. Limited data suggest that the 'chemically small crack' effect, observed in other alloy system, is not pronounced in Al-Li alloys. Modeling of environmental fatigue in Al-Li-Cu alloys related accelerated fatigue crack growth in moist air and salt water to hydrogen embrittlement.

  10. Gold color in dental alloys.

    Science.gov (United States)

    Cameron, T

    1997-01-01

    This article will help the dental laboratory with alloy selection by exploring how the relationship among color, ductility and strength applies to gold and how color can be quantified. Because higher quality materials translate into higher profits, upselling to the dentist and patient is also discussed. PMID:9524484

  11. Creep of Mg-alloys.

    Czech Academy of Sciences Publication Activity Database

    Blum, W.; Eisenlohr, P.; Zeng, X. H.; Mili?ka, Karel

    Montreal : Canadian Institute of Mining, Metallurgy and Petroleum , 2006 - (Pekguleryuz, M.; Mackenzie, L.), s. 633-645 ISBN 1-894475-66-6. [Magnesium Technology in the Global Age. Montreal (CA), 01.10.2006-04.10.2006] Institutional research plan: CEZ:AV0Z20410507 Keywords : creep * magnesium alloys * creep mechanisms Subject RIV: BM - Solid Matter Physics ; Magnetism

  12. Thermodynamic Database for Zirconium Alloys

    International Nuclear Information System (INIS)

    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 designers. In this thesis some aspects of the development of a thermodynamic database for zirconium alloys are presented. A thermodynamic database represents an important facility in applying thermodynamic equilibrium calculations for a given material providing: 1) relevant information about the thermodynamic properties of the alloys e.g. amount and composition of phases, oxygen activity, heat capacity etc, and 2) significant information for the manufacturing process e.g. heat treatment temperature. The basic information in the database is first the unary data, i.e. pure elements; those are taken from the compilation of the Scientific Group Thermodata Europe (SGTE) and then the binary and ternary systems. All phases present in those binary and ternary systems are described by means of the Gibbs energy as a function of composition and temperature. Many of those binary systems have been taken from published or unpublished works and others have been assessed in the present work. The elements included in the database are: C, Fe, Cr, Nb, Ni, Mo, O, Si, Sn, and Zr + H, and the assessment performed under this thesis are: Cr-Sn, Mo-Zr, Sn-Zr, Fe-Nb-Zr and Nb-O-Zr. All the calculations have been made using Thermo-Calc software and the representation of the Gibbs energy obtained by applying Calphad technique with some use of ab initio calculations

  13. Oxide characterization and hydrogen behaviors of Zr-based alloys

    International Nuclear Information System (INIS)

    The work scope and contents of the research are as follows : basic properties of zirconium alloys, hydrogen pick-up mechanism of zirconium alloy, effects of hydride on the corrosion behaviors of zirconium alloys, estimation on stress of oxide layer in the zirconium alloy, microstructure and characteristic of oxide in pre-hydrided zirconium alloys

  14. Development of temperature statistical model when machining of aerospace alloy materials

    OpenAIRE

    Kadirgama Kumaran; Rahman Md. Mustafizur; Mohamed Basir; Bakar Rosli Abu; Ismail Ahmad Rasdan

    2014-01-01

    This paper presents to develop first-order models for predicting the cutting temperature for end-milling operation of Hastelloy C-22HS by using four different coated carbide cutting tools and two different cutting environments. The first-order equations of cutting temperature are developed using the response surface methodology (RSM). The cutting variables are cutting speed, feed rate, and axial depth. The analyses are carried out with the aid of the statis...

  15. Creep properties and simulation of weld repaired low alloy heat resistant CrMo and Mo steels at 540 deg C. Sub-project 2 - Ex-serviced 2.25Cr1M0 weld metal and cross weld repairs

    Energy Technology Data Exchange (ETDEWEB)

    Rui Wu; Storesund, Jan; Borggreen, Kjeld; Feilitzen, Carl von

    2007-12-15

    Weld repair has been carried out in an ex-serviced 10 CrMo 9 10 pipe by using 10 CrMo 9 10, 13 CrMo 4 4 and 15 Mo 3 consumables. Application of current welding procedure and consumables results in an over matched weld repair. This is verified by both creep tests and the creep simulations at even lower stresses than tested. Creep specimens have been extracted from ex-serviced 10 CrMo 9 10 parent metal (PM) and weld metal (WM), from virgin 10 CrMo 9 10 WM, from virgin 13 CrMo 4 4 WM, and from virgin 15 Mo 3 WM. In addition, cross weld specimens including weld metal, heat affected zone (HAZ) and parent metal have been taken from the ex-serviced 10 CrMo 9 10 weld joint, and from three weld repairs. In total, there are nine test series. The sequence of creep lifetime at 540 deg C at given stresses is; virgin 10 CrMo 9 10 weld metal > virgin 15 Mo 3 weld metal approx virgin 13 CrMo 4 4 weld metal approx ex-serviced 10 CrMo 9 10 weld metal >> ex-serviced 10 CrMo 9 10 parent metal > ex-serviced 10 CrMo 9 10 cross weld approx 10 CrMo 9 10 cross weld repair approx 13 CrMo 4 4 cross weld repair approx and 15 Mo 3 cross weld repair. All the series show good creep ductility. The ex-serviced 10 CrMo 9 10 parent metal shows a creep lifetime about one order of magnitude shorter than that for both the virgin parent metal and the ex-serviced 10 CrMo 9 10 weld metal, independent of stresses. Differences in creep lifetime among the ex-serviced 10 CrMo 9 10 cross weld and other cross weld repairs are negligible, simply because rupture always occurred in the ex-serviced 10 CrMo 9 10 parent metal, approximately 10 mm from HAZ, for all the cross welds. Necking is frequently observed in the ex-serviced 10 CrMo 9 10 parent metal at the opposite side of the fracture. Creep damage to a large and a small extend is found adjacent to the fracture and at the necking area, respectively. Other parts of the weld joint like weld metal and HAZ are damage-free, independent of stress, weld metal and material condition. Norton's law, Monkman-Grant relation and phi- and OMEGA-models (strain-strain rate) are valid for all the tested series. These models can be utilised for lifetime assessment. Using phi- and OMEGA-models, for instance, creep strain with respect to time can be successfully reproduced and reproduced creep curves aggress well with the experiments. Finite element simulations based on dimension of weld repaired pipe and weld repair geometry have been performed using obtained creep results and have been extrapolated down to 60 MPa. It shows that severe creep damage and rupture occur in HAZ for 13 CrMo 4 4 and 15 Mo 3 cross weld repairs. This is also true for 10 CrMo 9 10 cross weld repair with axial stress. Extra axial load reduces the creep life of 13 CrMo 4 4 and 15 Mo 3 weld repairs. However, the extra axial load prolongs somewhat the creep life for the 10 CrMo 9 10 repair, as a result of an extended area of stress enhancement and consequently a reduction of the highest stress The simulations exhibit that creep damage may initiate and develop deep inside the wall of cross weld repairs. This gives rise to a warning that application of methods for detection of surface creep damage may be insufficient in the case of repaired welds

  16. Interdiffusion during the formation of amorphous alloys by mechanical alloying

    International Nuclear Information System (INIS)

    By probing the Ni content of Zr crystallites as a function of milling time using Auger spectroscopy, we report the first direct measurements of the interdiffusion which takes place during the amorphization of Ni-Zr by the mechanical alloying of pure-metal powders. Based on the concentration variation of Ni in Zr as a function of the milling time and using a simple interdiffusion model, we can estimate an effective local temperature at the collision site

  17. Cast bulk glassy alloys: fabrication, alloy development and properties

    OpenAIRE

    Qingsheng Zhang; Chunling Qin; Akihisa Inoue

    2010-01-01

    Metallic glasses represent an interesting group of materials as they possess outstanding physical, chemical and mechanical properties compared to their crystalline counterparts. Currently, with well designed compositions it is possible to cast liquid alloys into the glassy state at low critical cooling rates from 100 K•s-1 to 1 K•s-1 and in large critical sample sizes up to several centimeters, which significantly enhances the promise for possible applications as advanced engineering material...

  18. Crevice corrosion propagation on alloy 625 and alloy C276 in natural seawater

    International Nuclear Information System (INIS)

    Chemical composition of the aqueous solution within crevices on two different Ni-Cr-Mo-Fe alloys immersed in natural seawater was determined using a semiquantitative thin-layer chromatographic method. Active crevices were found to contain concentrated amounts of dissolved Ni2+, Cr3+, Mo3+, and Fe2+ ions. Propagation of crevice corrosion for the two alloys was determined from anodic polarization curves in model crevice solutions based upon stoichiometric dissolution or selective dissolution of alloy components. Both alloys 625 (UNS N06625) and C276 (UNS N10276) underwent crevice corrosion in the model crevice electrolytes. For the model crevice solution based upon selective dissolution of alloy constituents, the anodic dissolution rate for alloy 625 was higher than that for alloy C276. This trend was reversed for the model crevice solution based upon uniform dissolution of alloy constituents

  19. Micro-Structures of Hard Coatings Deposited on Titanium Alloys by Laser Alloying Technique

    Science.gov (United States)

    Li, Wei; Yu, Huijun; Chen, Chuanzhong; Wang, Diangang; Weng, Fei

    2013-02-01

    This work is based on micro-structural performance of the Ti-B4C-C laser alloying coatings on Ti-6Al-4V titanium alloy. The test results indicated that laser alloying of the Ti-B4C-C pre-placed powders on the Ti-6Al-4V alloy substrate can form the ceramics reinforced hard alloying coatings, which increased the micro-hardness and wear resistance of substrate. The test result also indicated that the TiB phase was produced in alloying coating, which corresponded to its (101) crystal plane. In addition, yttria has a refining effect on micro-structures of the laser alloying coating, and its refinement mechanism was analyzed. This research provided essential experimental and theoretical basis to promote the applications of the laser alloying technique in manufacturing and repairing of the aerospace parts.

  20. Effect of alloying on the properties of the MR-47-VP alloy

    International Nuclear Information System (INIS)

    Alloying of Mo-45 Re with 0.43-19.88 wt.% Ti, Zr, Hf, Nb, Ta, V or W increased tensile strength and yield strength and decreased elongation. In ternary alloys, the average effect decreased in the order Hf > Zr > Ti > Ta > Nb > Y. Alloying with 86% plastic deformation of the 20 ? diameter alloy wire increased tensile strength by a factor of approximately 5

  1. Characteristics of K-alloys with the small changes of alloying elements

    International Nuclear Information System (INIS)

    The new developed alloys(Zr-0.2Nb-1.1Sn series alloys and Zr-0.4Nb-0.8Sn series alloys) for high burn-up fuel cladding were evaluated to investigate the effect of small change of alloying elements, including the Nb, Sn, Fe, Fe, Cr, Cu, Mo, Mn, on the microstructures, corrosion resistance, tensile strength, and creep rate. The corrosion resistance of Zr-0.2Nb-1.1Sn series alloys was similar to that of Zr-0.4Nb-0.8Sn series alloys in the 360 .deg. C water condition, but Zr-0.2Nb-1.1Sn series alloys had slightly higher weight gain than Zr-0.4Nb-0.8Sn series alloys in both 360 .deg. C LiOH and 400 .deg. C steam conditions. And the corrosion resistance of this study showed superior to that of commercial ZIRLO cladding. Under the three corrosion conditions, the corrosion resistance of Cu containing alloy in Zr-0.2Nb-1.1Sn system was improved in the comparison with Mo containing alloy, and the corrosion resistance of Cu containing alloy in Zr-0.4Nb-0.8Sn system was most excellent. The effect of tensile strength in both conditions of room temperature and 400 .deg. C was not observed with the small changes of alloying elements. The creep resistance of Mo containing alloy was better than that of Cu containing alloy and the creep resistance of 0.3% Fe containing alloy was better than that of 0.4% Fe containing alloy

  2. Entropies in Alloy Design for High-Entropy and Bulk Glassy Alloys

    OpenAIRE

    Akihiro Makino; , Wei Zhang; Kunio Yubuta; Kenji Amiya; Takeshi Wada; Akira Takeuchi

    2013-01-01

    High-entropy (H-E) alloys, bulk metallic glasses (BMGs) and high-entropy BMGs (HE-BMGs) were statistically analyzed with the help of a database of ternary amorphous alloys. Thermodynamic quantities corresponding to heat of mixing and atomic size differences were calculated as a function of composition of the multicomponent alloys. Actual calculations were performed for configurational entropy (Sconfig.) in defining the H-E alloys and mismatch entropy (Ss) normalized with Boltzmann constant (k...

  3. Bonding theory for metals and alloys

    CERN Document Server

    Wang, Frederick E

    2005-01-01

    Bonding Theory for Metals and Alloys exhorts the potential existence of covalent bonding in metals and alloys. Through the recognition of the covalent bond in coexistence with the 'free' electron band, the book describes and demonstrates how the many experimental observations on metals and alloys can all be reconciled. Subsequently, it shows how the individual view of metals and alloys by physicists, chemists and metallurgists can be unified. The physical phenomena of metals and alloys covered in this book are: Miscibility Gap between two liquid metals; Phase Equilibrium Diagrams; Phenomenon of Melting. Superconductivity; Nitinol; A Metal-Alloy with Memory; Mechanical Properties; Liquid Metal Embrittlement; Superplasticity; Corrosion; The author introduces a new theory based on 'Covalon' conduction, which forms the basis for a new approach to the theory of superconductivity. This new approach not only explains the many observations made on the phenomenon of superconductivity but also makes predictions that ha...

  4. Annealing behavior of high permeability amorphous alloys

    International Nuclear Information System (INIS)

    Effects of low temperature annealing on the magnetic properties of the amorphous alloy Co714Fe46Si96B144 were investigated. Annealing this alloy below 4000C results in magnetic hardening; annealing above 4000C but below the crystallization temperature results in magnetic softening. Above the crystallization temperature the alloy hardens drastically and irreversibly. Conventional and high resolution transmission electron microscopy were used to show that the magnetic property changes at low temperatures occur while the alloy is truly amorphous. By imaging the magnetic microstructures, Lorentz electron microscopy has been able to detect the presence of microscopic inhomogeneities in this alloy. The low temperature annealing behavior of this alloy has been explained in terms of atomic pair ordering in the presence of the internal molecular field. Lorentz electron microscopy has been used to confirm this explanation

  5. 21 CFR 872.3060 - Noble metal alloy.

    Science.gov (United States)

    2010-04-01

    ...2010-04-01 2010-04-01 false Noble metal alloy. 872.3060 Section 872.3060... Prosthetic Devices § 872.3060 Noble metal alloy. (a) Identification . A noble metal alloy is a device composed primarily of...

  6. 21 CFR 872.3710 - Base metal alloy.

    Science.gov (United States)

    2010-04-01

    ...2010-04-01 2010-04-01 false Base metal alloy. 872.3710 Section 872.3710 ...DEVICES Prosthetic Devices § 872.3710 Base metal alloy. (a) Identification . A base metal alloy is a device composed primarily of...

  7. Method of treating Ti--Ni--Zr--Ta superconducting alloys

    International Nuclear Information System (INIS)

    A superconducting metal alloy is formulated from 10 to 50 at.% Ti, 20 to 50 at.% Nb, 10 to 40 at.% Zr and 5 to 12 at.% Ta. A Ti-Nb-Zr-Ta superconducting alloy with a fine, non-homogeneous structure is obtained by forming a ? solid solution of said Ti-Nb-Zr-Ta alloy by heating the alloy to a temperature within the ? solid solution range, cooling and then cold working said heated alloy, heating said cold worked alloy to a temperature within the (?' + ?'') alloy to maintain the peritectoid structure, cold working the peritectoid alloy, heating said peritectoid alloy to a temperature within the eutectoid range to form a multiphase eutectoid alloy structure and then cooling said eutectoid alloy and finally cold working the eutectoid alloy. 1 claim, 8 figures

  8. Protective enamels for vanadium and vanadium alloys

    International Nuclear Information System (INIS)

    Both pure vanadium and vanadium alloys-7.9 tungsten and vanadium-10% titanium, 5% chromium were used for the development of protective coating of vanadium and its alloys against hydride embrittlement. Enamel was prepared by means of grinding frit, its basis being alumoborosilicate glass with oxides of alkaline earth and sodium. It is shown that the enamels prepared feature a good adhesion to vanadium. At least a two-layer enamelling is necessary for vanadium and its alloys

  9. Magnesium alloys for structural applications ; recent advances

    OpenAIRE

    Westengen, H.

    1993-01-01

    Magnesium alloys possess unique properties, which when fully exploited can open up for major inroads into important markets for structural applications. A density of 2/3 that of Al, and only slightly higher than for fibre reinforced plastics, combined with excellent mechanical and physical properties as well as processability and recyclability, make magnesium alloys an obvious choice when designing for light weight. The paper summarizes some basic aspects of magnesium alloying practice, and d...

  10. Alloy nanoparticle synthesis using ionizing radiation

    Science.gov (United States)

    Nenoff, Tina M. (Sandia Park, NM); Powers, Dana A. (Albuquerque, NM); Zhang, Zhenyuan (Durham, NC)

    2011-08-16

    A method of forming stable nanoparticles comprising substantially uniform alloys of metals. A high dose of ionizing radiation is used to generate high concentrations of solvated electrons and optionally radical reducing species that rapidly reduce a mixture of metal ion source species to form alloy nanoparticles. The method can make uniform alloy nanoparticles from normally immiscible metals by overcoming the thermodynamic limitations that would preferentially produce core-shell nanoparticles.

  11. A bidirectional shape memory alloy folding actuator

    OpenAIRE

    Paik, Jamie; Wood, Robert J.

    2012-01-01

    This paper presents a low-profile bidirectional folding actuator based on annealed shape memory alloy sheets applicable for meso-and microscale systems. Despite the advantages of shape memory alloys-high strain, silent operation, and mechanical simplicity-their application is often limited to unidirectional operation. We present a bidirectional folding actuator that produces two opposing 180 degrees motions. A laser-patterned nickel alloy (Inconel 600) heater localizes actuation to the foldin...

  12. Peculiarities of hydrogen plasticization of titanium alloys

    International Nuclear Information System (INIS)

    Hydrogen effect on ductility and resistance to deformation of the VT 14 and VT 22 titanium alloys in the temperature range of hot doeformation is estimated in the paper. It is shown that the hydrogen effect is determined by phase composition of the alloys, temperature and deformation rate. Decrease of the temperature of polymorphic transformation in the alloys with hydrogen permits to decrease the temperature of superplasticity manifestation

  13. Modeling Asymmetric Rolling Process of Mg alloys

    International Nuclear Information System (INIS)

    Asymmetric deformation during rolling can arise in various ways: difference in the radii, speeds, frictions of the top and bottom rolls. Asymmetric warm rolling processes of magnesium alloys were modeled using a lagrangian incremental approach. A constitutive equation representing flow behaviors of AZ31 magnesium alloys during warm deformation was implemented to the modeling. Various roll speed ratios were introduced to investigate deformation behaviors of the magnesium alloys. Bending and texturing of the strips were examined.

  14. Nickel Aluminide Alloys Made By Rapid Solidification

    Science.gov (United States)

    Ray, Ranjan

    1995-01-01

    Collection of reports describes experimental metallurgical studies of nickel aluminide alloys made by rapid-solidification powder-metallurgy process. Process incorporates ultrafine dispersions of hard, stable refractory compounds and rare-earth oxides into alloys. Effects of dispersoids on high-temperature mechanical properties (flow stress, and compressive and tensile creep) of alloys investigated. Results indicate specific additives result in improved strength and ductility.

  15. Recent developments in advanced aircraft aluminium alloys

    International Nuclear Information System (INIS)

    Highlights: • To compete with composites, performance of aluminium alloys should be increased. • Al–Li alloys have higher strength, fracture and fatigue/corrosion resistance. • Improvements of aerospace Al alloys are due to optimised solute content and ratios. • In selecting new materials, there should be no reduction in the level of safety. • The use of hybrid materials could provide additional opportunities for Al alloys. - Abstract: Aluminium alloys have been the primary material for the structural parts of aircraft for more than 80 years because of their well known performance, well established design methods, manufacturing and reliable inspection techniques. Nearly for a decade composites have started to be used more widely in large commercial jet airliners for the fuselage, wing as well as other structural components in place of aluminium alloys due their high specific properties, reduced weight, fatigue performance and corrosion resistance. Although the increased use of composite materials reduced the role of aluminium up to some extent, high strength aluminium alloys remain important in airframe construction. Aluminium is a relatively low cost, light weight metal that can be heat treated and loaded to relatively high level of stresses, and it is one of the most easily produced of the high performance materials, which results in lower manufacturing and maintenance costs. There have been important recent advances in aluminium aircraft alloys that can effectively compete with modern composite materials. This study covers latest developments in enhanced mechanical properties of aluminium alloys, and high performance joining techniques. The mechanical properties on newly developed 2000, 7000 series aluminium alloys and new generation Al–Li alloys are compared with the traditional aluminium alloys. The advantages and disadvantages of the joining methods, laser beam welding and friction stir welding, are also discussed

  16. Corrosionand Biocompatibility Assessment of Magnesium Alloys

    OpenAIRE

    Norman Munroe; Rupak Dua; Puneet Gill; Sharan Ramaswamy

    2011-01-01

    Magnesium due to its good biocompatibility, mechanical properties, necessity in metabolic processes and lightness in weight, is an ideal candidate for biodegradable implants. The major concerns with magnesium and its alloys are that of rapid and non-uniform corrosion. In this investigation, magnesium based binary, ternary and quaternary alloys were studied for their corrosion resistance and biocompatibility. In vitro corrosion resistance of the alloys was studied in accorda...

  17. Molybdenum disilicide alloy matrix composite

    Science.gov (United States)

    Petrovic, John J. (Los Alamos, NM); Honnell, Richard E. (Los Alamos, NM); Gibbs, W. Scott (Los Alamos, NM)

    1990-01-01

    Compositions of matter consisting of matrix matrials having silicon carbide dispersed throughout them and methods of making the compositions. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms.

  18. Cluster strengthening in aluminium alloys

    International Nuclear Information System (INIS)

    We consider the elastic effect of clusters and propose a size misfit strengthening model. Our approach is similar to solute strengthening, where the size misfit of clusters is assumed to be the sum of elementary atomic misfits. The proposed model is compared to the coherency strengthening model, and the results indicate that our model is applicable to clusters ?<1 nm in diameter. The prediction of the model is reasonably consistent with the reported experiments of aluminium alloys

  19. Fluidity of Aluminium Foundry Alloys

    OpenAIRE

    Di Sabatino, Marisa

    2005-01-01

    The fluidity of an alloy plays a key role for the foundry and transport industries as it affects the quality and soundness of the cast products. Particularly, fluidity influences the reject rates, hence casting costs and the production of thinwalled, hence light components. Fluidity is a complex technological property and depends on many parameters. However, many aspects of this subject are still not fully understood. The motivation of the research presented in this doctoral thesis was, there...

  20. Microstructural characterization of EXCEL alloy

    International Nuclear Information System (INIS)

    The microstructure of Excel alloy was studied by optical and scanning electron microscopy. X-ray diffraction was used to analyze the present phases. Characteristic peaks of ?-Zr (HCP), ?-Zr (BCC) and ?hydride (FCC) were identified. The high relatives intensities of certain peaks suggest that samples are textured. Basal poles were dominant in radial-longitudinal planes and prismatic poles have the highest concentration in radial-tangential planes (author)

  1. Phase diagrams for surface alloys

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Ruban, Andrei; Stoltze, Per; Jacobsen, Karsten Wedel; Skriver, Hans Lomholt; Nørskov, Jens Kehlet; Besenbacher, Flemming

    1997-01-01

    We discuss surface alloy phases and their stability based on surface phase diagrams constructed from the surface energy as a function of the surface composition. We show that in the simplest cases of pseudomorphic overlayers there are four generic classes of systems, characterized by the sign of the heat of segregation from the bulk and the sign of the excess interactions between the atoms in the surface (the surface mixing energy). We also consider the more complicated cases a with ordered surf...

  2. ALITHALITE ® ALLOY DEVELOPMENT AND PRODUCTION

    OpenAIRE

    Bretz, P.

    1987-01-01

    In 1981, the ALITHALITE ® aluminum-lithium project was established at Alcoa Laboratories, with the goal of developing low-density replacements for a variety of incumbent aerospace aluminum products. 1987 finds one of these alloys, 2090, production-ready in a range of products and a variety of tempers. Sufficient development of both sheet and extruded shapes permits the establishing of tentative mechanical property limits for several medium to highstrength targets. Thin plate, which generally ...

  3. Cr - Ni system alloys composition impact on durability value

    OpenAIRE

    A. Z. Issagulov; S. S. Kvon; V. Yu. Kulikov; A. A. Sakbossynova

    2014-01-01

    There are considered the alloys of the Cr – Ni system with addition of iron, molybdenum and other alloying elements. In the alloys there varied chrome content from 35 to 55 %. The alloys were subjected to various types of heat treatment. There were measured mechanical properties at the room temperature, then the alloys were studied for the durability limit. There was additionally studied the impact of chrome content in the alloy and operation temperatures on the value of rupture stress. All t...

  4. Pack cementation coatings for alloys

    Energy Technology Data Exchange (ETDEWEB)

    He, Yi-Rong; Zheng, Minhui; Rapp, R.A. [Ohio State Univ., Columbus, OH (United States)

    1996-08-01

    The halide-activated pack cementation process was modified to produce a Ge-doped silicide diffusion coating on a Cr-Cr{sub 2}Nb alloy in a single processing step. The morphology and composition of the coating depended both on the composition of the pack and on the composition and microstructure of the substrate. Higher Ge content in the pack suppressed the formation of CrSi{sub 2} and reduced the growth kinetics of the coating. Ge was not homogeneously distributed in the coatings. In cyclic and isothermal oxidation in air at 700 and 1050{degrees}C, the Ge-doped silicide coating protected the Cr-Nb alloys from significant oxidation by the formation of a Ge-doped silica film. The codeposition and diffusion of aluminum and chromium into low alloy steel have been achieved using elemental Al and Cr powders and a two-step pack cementation process. Sequential process treatments at 925{degrees}C and 1150{degrees}C yield dense and uniform ferrite coatings, whose compositions are close to either Fe{sub 3}Al or else FeAl plus a lower Cr content, when processed under different conditions. The higher content of Al in the coatings was predicted by thermodynamic calculations of equilibrium in the gas phase. The effect of the particle size of the metal powders on the surface composition of the coating has been studied for various combinations of Al and Cr powders.

  5. Historical development of alloy 800

    International Nuclear Information System (INIS)

    Alloy 800 was developed in 1949 by The International Nickel Company, Inc. The basic composition, nominally 32wt.%Ni, 20.5wt.%Cr and 46wt.%Fe, was designed to provide a stable, fully austenitic structure and to impart high strength combined with resistance to oxidation, carburization and corrosion in a wide variety of aggressive industrial environments at elevated temperatures. In the short span of twenty-five years, alloy 800 has earned a unique position in the family of heat- and corrosion-resistant materials. Established uses include a wide range of applications in the industrial heating field, in the petro-chemical industry, in domestic appliances and in food processing equipment. The good performance of alloy 800 in these applications has led to its use as boiler tube material both in fossil-fired plants and in HTGR and PWR nuclear power systems. Recently, it was specified for a PHW CANDU reactor and it is now being considered as heat exchanger tube material for the LMFBR and for coal gasification reactor vessel internals. (author)

  6. Superplastic properties of magnesium alloys

    Directory of Open Access Journals (Sweden)

    M. Greger

    2007-06-01

    Full Text Available Purpose: The paper summarises results of experiments aimed at development of structure of modified Mg-Al-Zn alloys at hot deformation.Design/methodology/approach: Methods ARB and ECAP were used in the described experiment. It was proved that hardly forming materials could achieve very high plastics properties.Findings: After making plastics deformation, the using materials of alloys AZ61 and AZ91 analysed superplastics behaviour, it was certified by obtaining results, when ductility to rupture of alloy AZ91 was 418 %, it is demostrated at conclusion of the article.Research limitations/implications: The experiment proved big influence of previous plastics deformation to ending values of mechanical properties. It was verified that better results are at rolling in more steps compared to rolling in one pass.Practical implications: The low submission temperature at last pass through die it causes obtaining higher final properties.Originality/value: It was obtained the material about grain size d ? 0,7?m during using the technology of ECAP. Abreast of it the technology ARB enabled to get material of grain size in interval d ? 1-10 ?m. The sekond technology brings higher strength properties. Only 3 cycles were sufficient to lower original grain size under limit 10 ?m

  7. Casting Characteristics of Aluminum Die Casting Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

    The research program investigates the casting characteristics of selected aluminum die casting alloys. Specifically, the alloys' tendencies towards die soldering and sludge formation, and the alloys' fluidity and machinability are evaluated. It was found that: When the Fe and Mn contents of the alloy are low; caution has to be taken against possible die soldering. When the alloy has a high sludge factor, particularly a high level of Fe, measures must be taken to prevent the formation of large hardspots. For this kind of alloy, the Fe content should be kept at its lowest allowable level and the Mn content should be at its highest possible level. If there are problems in die filling, measures other than changing the alloy chemistry need to be considered first. In terms of alloy chemistry, the elements that form high temperature compounds must be kept at their lowest allowable levels. The alloys should not have machining problems when appropriate machining techniques and machining parameters are used.

  8. Nondestructive determination of mechanical properties. [aluminum alloys

    Science.gov (United States)

    Schneider, E.; Chu, S. L.; Salma, K.

    1984-01-01

    Aluminum alloys of types 1100, 3003, 5052, 6061, and 2024 were used to study the sensitivity of the acousto-elastic constant to changes in the microstructure. Results show that there is a strong relationship between the acousto-elastic constants and the yield strength and hardness. This relationship depends on whether the alloy is strain hardened or precipitation hardened. In strain hardened alloys, the constants increase as the amount of solid solution is decreased, while the behavior is the opposite in precipitation hardened alloys.

  9. Titanium alloys Russian aircraft and aerospace applications

    CERN Document Server

    Moiseyev, Valentin N

    2005-01-01

    This text offers previously elusive information on state-of-the-art Russian metallurgic technology of titanium alloys. It details their physical, mechanical, and technological properties, as well as treatments and applications in various branches of modern industry, particularly aircraft and aerospace construction. Titanium Alloys: Russian Aircraft and Aerospace Applications addresses all facets of titanium alloys in aerospace and aviation technology, including specific applications, fundamentals, composition, and properties of commercial alloys. It is useful for all students and researchers interested in the investigation and applications of titanium.

  10. Characterization of a NIMONIC TYPE super alloy

    International Nuclear Information System (INIS)

    Mechanical properties of strength and thermofluence of a NIMONIC type super alloy under thermal treatment was determined. The relationship between microstructure, phases and precipitates was also studied. (author)

  11. Cavitation strength of cermet hard alloys

    International Nuclear Information System (INIS)

    The description of studies carried out at NSC KIPT was given on investigation of cavitation strength of construction materials. It was studied the cermet alloys of the following grades: WC-Co, WC-TiC-Co, WC-TiC-TaC-Co under the cavitation effect. It was measured the dependence of alloy strength of the cobalt content. It was shown that the interaction between cavitation strength and microhardness for high cobalt alloys WC-Co is determined with proportion Zh = 1.24·10-2·H?1,46, and for the alloys of WC-TiC-Co degree by Zh 48.8·H?-1,72.

  12. Refractory phases in powder metallurgy tungsten alloys

    International Nuclear Information System (INIS)

    According to the calculation of thermodynamical stability of interstitial phases in powder metallurgy (P.M.) tungsten alloys, the possibility of obtaining HfC particles in W-HfC-C alloys was shown. Structure and properties of P.M. tungsten alloys with HfC, TaC, NbC (up to 1 mas.%) and carbon (up to 0.06 mas.%) with Me/C ratio from 1:4 to 1:1.5 were investigated. Tungsten alloys with NbC and TaC have equilibria phase composition W+W2C after sintering, whereas in alloys with HfC, carbides W2C and HfC and oxides HfO2 were present after the same treatment. In W-HfC-C alloys during deformation and heat treatment the processes of ageing, i.e. formation of disperse particles with average diameters 100-500 A were developed. These particles stabilised the structure of alloys after deformation during heat treatment at temperatures up to 18000C. The temperature of the onset of recrystallisation in W-HfC-C alloys is 200-2500C higher than in alloys with NbC and TaC. (Auth.)

  13. Clinical evaluation of three amalgam alloys.

    Science.gov (United States)

    Tyas, M J; Ewers, G J

    1993-06-01

    A total of 117 high-copper amalgams of three types (platinum-modified, palladium-modified and dispersed phase) was placed by two operators in 59 patients. Restorations were assessed for marginal fracture, tarnish, corrosion, and tooth staining on continuous linear photographic rating scales. After one year, the platinum- and palladium-modified alloys showed a significant amount of tarnish, and all three alloys had statistically significant marginal fracture. The only significant difference between alloys at one year was the greater tarnish of the platinum-modified alloy. There was no association between static creep and marginal fracture. PMID:8373297

  14. Ti-Ni Shape Memory Alloys

    International Science & Technology Center (ISTC)

    Development of Advanced Technology of Thermomechanical Treatment Forming Well-Developed Substructure and Nanocrystalline Structure for Improvement of Functional Properties of Ti-Ni Shape Memory Alloys

  15. SP-700 titanium alloy data sheets

    International Nuclear Information System (INIS)

    SP-700, an emerging ?-rich ?+? titanium alloy, is designed to improve superplastic formability as well as mechanical properties over Ti-6Al-4V alloy. Owing to its fine microstructure and low ?-transus temperature, it is superplastic-formable at temperature below 1,073K (800 C) with low flow stress. Remarkable workability of this alloy is also retained in conventional Manufacturing processes. Another advantage of SP-700 is heat treatment response which includes deep hardenability and quick aging kinetics. Corrosion resistance and machinability are equivalent to or better than Ti-6Al-4V alloy

  16. Bulk amorphous Mg-based alloys

    DEFF Research Database (Denmark)

    Pryds, Nini

    2004-01-01

    The present paper describes the preparation and properties of bulk amorphous quarternary Mg-based alloys and the influence of additional elements on the ability of the alloy to form bulk amorphous. The main goal is to find a Mg-based alloy system which shows both high strength to weight ratio and a low glass transition temperature. The alloys were prepared by using a relatively simple technique, i.e. rapid cooling of the melt in a copper wedge mould. The essential structural changes that are ach...

  17. Surface treatment of new type aluminum lithium alloy and fatigue crack behaviors of this alloy plate bonded with Ti–6Al–4V alloy strap

    International Nuclear Information System (INIS)

    Highlights: ? A new generation aluminum lithium alloy which special made for Chinese commercial plane was investigated. ? Pattern of aluminum lithium alloy and Ti alloy were shown after anodization. ? Crack propagation of samples bonded with different wide Ti straps were studied in this paper. -- Abstract: Samples consisting of new aluminum lithium alloy (Al–Li alloy) plate developed by the Aluminum Company of America and Ti–6Al–4V alloy (Ti alloy) plate were investigated. Plate of 400 mm × 140 mm × 2 mm with single edge notch was anodized in phosphoric solution and Ti alloy plate of 200 mm × 20 (40) mm × 2 mm was anodized in alkali solution. Patterns of two alloys were studied at original/anodized condition. And then, aluminum alloy and Ti alloy plates were assembled into a sample with FM 94 film adhesive. Fatigue crack behaviors of the sample were investigated under condition of nominal stress ? = 36 MPa and 54 MPa, stress ratio of 0.1. Testing results show that anodization treatment modifies alloys surface topography. Ti alloy bonding to Al–Li alloy plate effectively retards crack growth than that of Al–Li alloy plate. Fatigue life of sample bonded with Ti alloy strap improves about 62.5% than that of non-strap plate.

  18. Activation analysis for different structural alloys considered for ITER

    International Nuclear Information System (INIS)

    Activation calculations have been made for the austentic steel 316SS, the ferritic alloy HT-9, the titanium alloy Ti6A14V, and the vanadium alloy V5Cr5Ti in a liquid metal (Na) design suggested recently for ITER. The calculations show that the vanadium alloy has the minimum short and long-term radioactivity and BHP. It also has the minimum decay heat at all the time. The titanium alloy has less radioactivity than the austenitic and this ferritic alloys. However, the decay heat of this alloy could exceed that of the conventional alloys

  19. Irradiation-assisted stress corrosion cracking in HTH Alloy X-750 and Alloy 625

    International Nuclear Information System (INIS)

    In-reactor testing of bolt-loaded compact tension specimens was performed in 360 C water to determine the irradiation-assisted stress corrosion cracking (IASCC) behavior of HTH Alloy X-750 and direct-aged Alloy 625. New data confirm previous results showing that high irradiation levels reduce SCC resistance in Alloy X-750. Heat-to-heat variability correlates with boron content, with low boron heats showing improved IASCC properties. Alloy 625 is resistant to IASCC, as no cracking was observed in any Alloy 625 specimens. Microstructural, microchemical and deformation studies were performed to characterize the mechanisms responsible for IASCC in Alloy X-750 and the lack of an effect in Alloy 625. The mechanisms under investigation are: boron transmutation effects, radiation-induced changes in microstructure and deformation characteristics, and radiation-induced segregation. Irradiation of Alloy X-750 caused significant strengthening and ductility loss that was associated with the formation of cavities and dislocation loops. High irradiation levels did not cause significant segregation of alloying or trace elements in Alloy X-750. Irradiation of Alloy 625 resulted in the formation of small dislocation loops and a fine body-centered-orthorhombic phase. The strengthening due to the loops and precipitates was apparently offset by a partial dissolution of ? double-prime precipitates, as Alloy 625 showed no irradiation-induced strengthening or ductility loss. In the nonirradiated condition, an IASCC susceptible HTH heat containing 28 ppm B showed grain boundary segregation of boron, whereas a nonsusceptible HTH heat containing 2 ppm B and Alloy 625 with 20 ppm B did not show significant boron segregation. Transmutation of boron to helium at grain boundaries, coupled with matrix strengthening, is believed to be responsible for IASCC in Alloy X-750, and the absence of these two effects results in the superior IASCC resistance displayed by Alloy 625

  20. Study of Alpha-Sigma Phase Transformation in Mechanically Alloyed Fe-Cr-Sn Alloys

    OpenAIRE

    Costa, B. F. O.; Caër, G. Le; Campos, N. Ayres de

    2001-01-01

    The solubility of tin is significantly extended by mechanical alloying in near equiatomic Fe-Cr alloys. The influences of Sn concentration and of grain size on the kinetics of formation of the sigma-phase have been studied using different techniques. The sigma-phase formation is much faster for as-milled alloys than it is for conventional alloys. The sigma-phase formation rate decreases with the increase of Sn concentration in alloys with nanometer-sized grains as it does in coarse-grained al...

  1. Effect of a microstructure and surface hydrogen alloying of a VT6 alloy on diffusion welding

    Science.gov (United States)

    Senkevich, K. S.; Skvortsova, S. V.; Kudelina, I. M.; Knyazev, M. I.; Zasypkin, V. V.

    2014-01-01

    The effect of a structural type (lamellar, fine, gradient) and additional surface alloying with hydrogen on the diffusion bonding of titanium alloy VT6 samples is studied. It is shown that the surface alloying of VT6 alloy parts with hydrogen allows one to decrease the diffusion welding temperature by 50-100°C, to obtain high-quality pore-free bonding, and to remove the "structural" boundary between materials to be welded that usually forms during welding of titanium alloys with a lamellar structure.

  2. Synthesis Of NiCrAlC alloys by mechanical alloying

    International Nuclear Information System (INIS)

    The purpose of the present paper is the synthesis of nickel alloys (NiCrAlC), which has been proposed like a economic alternative to the Stellite family Co alloys using mechanical alloying, followed by sintering heat treatment of milled material. The NiCrAlC alloys consist of a chromium carbides dispersion in a Ni3Al intermetallic matrix, that is easily synthesized by mechanical alloying. The use of mechanical alloying enables higher carbides sizes and distribution control in the matrix during sintering. We are also investigated the compaction of the processed materials by compressibility curves. The milling products were characterized by X-ray diffraction, and the end product was featured by conventional metallography and scanning electronic microscopy (SEM), that enabled the identification of desired phases, beyond microhardness test, which has been shown comparable to alloys manufactured by fusion after heat treating. (author)

  3. Scanning and transmission electron microscopy microstructure characterization of mechanically alloyed Nb-Ti-Al alloys.

    Science.gov (United States)

    Rozmus, Magdalena; Blicharski, Marek; Dymek, Stanis?aw

    2006-10-01

    Results are presented of an investigation of the microstructure development during mechanical alloying and following consolidation of an Nb15Ti15Al alloy. The alloy was synthesized from elemental as well as pre-alloyed powders. The microstructure of this material was examined by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. The use of pre-alloyed TiAl powder for synthesis of the Nb15Ti15Al alloy meant that a much shorter time was required to complete the mechanical alloying process compared with the synthesis of elemental powders. The investigation indicates that three phases were present in the consolidated materials: the Nb solid solution, the Nb(3)Al intermetallic phase and the dispersoid. PMID:17100907

  4. Zirconium alloys produced by recycling zircaloy tunings

    International Nuclear Information System (INIS)

    Highlights: •Zr–Ti alloys were successfully produced by two-step procedure. •Zircaloy tunings were used as a valuable source of Zr. •Zircaloy tunings and Ti powders was milled under hydrogen to produce hydride powders. •Hydride powders were decomposed by heating at 900 °C to synthesize the Zr-based alloy. •The procedure could be extended to the production of other Zr-based alloys. -- Abstract: Zircaloy chips were recycled to successfully produce Zr–Ti alloys with bcc structure and different compositions. The procedure developed involves two steps. First, the reactive mechanical alloying (RMA) of the zircaloy tunings and Ti powders was performed to produce metal hydride powders, with a high refinement of the microstructure and a Zr–Ti homogeneous composition. Second, the metal hydride powders were thermally decomposed by heating up to 900 °C to synthesize the Zr-based alloy with a selected composition. The change in the nature of the powders from ductile to brittle during milling avoids both cold working phenomena between the metals and the use of a control agent. A minimum milling time is necessary to produce the solid solution with the selected composition. The microstructure and structure of the final alloys obtained was studied. The present procedure could be extended to the production of Zr-based alloys with the addition of other metals different from Ti

  5. Physical Properties of High Entropy Alloys

    OpenAIRE

    Ming-Hung Tsai

    2013-01-01

    The majority of studies on high-entropy alloys are focused on their phase, microstructure, and mechanical properties. However, the physical properties of these materials are also encouraging. This paper provides a brief overview of the physical properties of high-entropy alloys. Emphasis is laid on magnetic, electrical, and thermal properties.

  6. ANALYSIS AND STUDY OF AMORPHOUS ALLOYS PROPERTIES

    Directory of Open Access Journals (Sweden)

    T.P. Pavlenko

    2013-10-01

    Full Text Available The paper reviews and analyzes properties of amorphous alloys for the purpose of their application in magnetic systems of electrical apparatus instead of high-permeability electric steels. The studies have shown a possibility of utilizing these alloys in the magnetic structure of a current transformer in the pulsed voltage stabilizer of an automated circuit-breaker semiconductor release.

  7. Intermetallic alloys: Deformation, mechanical and fracture behaviour

    International Nuclear Information System (INIS)

    The state of the art in intermetallic alloys development with particular emphasis on deformation, mechanical and fracture behaviour is documented. This review paper is prepared to lay the ground stones for a future work on mechanical property characterization and fracture behaviour of intermetallic alloys at GKSS. (orig.)

  8. 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)

  9. Alloys of clathrate allotropes for rechargeable batteries

    Science.gov (United States)

    Chan, Candace K; Miller, Michael A; Chan, Kwai S

    2014-12-09

    The present disclosure is directed at an electrode for a battery wherein the electrode comprises clathrate alloys of silicon, germanium or tin. In method form, the present disclosure is directed at methods of forming clathrate alloys of silicon, germanium or tin which methods lead to the formation of empty cage structures suitable for use as electrodes in rechargeable type batteries.

  10. Machining of uranium and uranium alloys

    International Nuclear Information System (INIS)

    Uranium and uranium alloys can be readily machined by conventional methods in the standard machine shop when proper safety and operating techniques are used. Material properties that affect machining processes and recommended machining parameters are discussed. Safety procedures and precautions necessary in machining uranium and uranium alloys are also covered. 30 figures

  11. Solidification shrinkage of Ni-Cr alloys

    International Nuclear Information System (INIS)

    Ni-Cr superalloy is widely used in casting of critical components in gas-turbine engines. Because of the significant change in density of alloy in mushy state, porosity is likely to arise in the alloy parts due to the solidification shrinkage. On the other hand, because Ni-Cr alloy is very hard and difficult to be machined, the net-shape casting of the alloy is a cheap process. Therefore, it is essential to measure the solidification shrinkage of mushy alloy for obtaining low-cost net-shape casting ingot without inner porosity. However, there have been a few reports on the solidification shrinkage of the liquid Ni-Cr alloy. In this work, the solidification shrinkage of Ni-Cr alloy was calculated by measuring its density using modified sessile drop method. It has been found that, for Ni-(0-24.53)% Cr alloys, the solidification shrinkage value fluctuates in the range of 0.91-2.02% and it tends to increase with increasing Cr concentration in 0-10% Cr. However, for Cr concentration more than 10%, the solidification shrinkage holds on a certain value of 2.00%

  12. Zirconium alloy heat treatment process and product

    International Nuclear Information System (INIS)

    Zirconium-base alloy channels and fuel cladding tubes having unique resistance to accelerated pustular corrosion in the boiling water reactor environment are produced by a heat treatment causing segregation of intermetallic particulate precipitate phase in two dimensional arrays preferably located along grain boundaries and subgrain boundaries throughout the alloy body

  13. Alloys oxidation of aluminium-scandium system

    International Nuclear Information System (INIS)

    Alloys and compounds of rare earth metals with aluminium thanks to their high corrosion stability, durability and small specific weight find to apply in various new techniques. On the base of carried out investigation it could be recommend as de oxidizing and alloying compositions containing 15-50 % of scandium as in possession of minimal oxidation

  14. Review of tantalum and niobium alloy production

    International Nuclear Information System (INIS)

    This paper concentrates on the current state of niobium- and tantalum-base alloy production. The materials requirements, alloy compositions of interest, and production status are discussed. Finally, a list of developments needed to support the SP-100 program will be identified. A bibliography is included

  15. Analytical techniques for uranium-based alloys

    International Nuclear Information System (INIS)

    Methods were developed for the analysis of uranium based alloys like U-Al, U-Al-Si, U-Ti and U-Mo alloys. The metal ions were estimated by AAS or spectrophotometry. The methods are simple and sensitive, and avoid the direct introduction of radioactive materials into the flame. (author)

  16. Precipitation of dispersoids in aluminum alloys

    International Nuclear Information System (INIS)

    The influence of alloy composition and preheat treatment on the precipitation of the metastable Al3Zr, ?', phase in ternary alloys and the subsequent recrystallization behavior was investigated. The ternary alloys contained zirconium and one of the following elements: copper, manganese, zinc, or silicon. Diffusion couples were constructed and the values for the interdiffusion coefficient for several elements in aluminum were calculated. The calculated values for the interdiffusion coefficients were used in a finite difference model for the prediction of the homogenization of an as-cast microstructure during preheating. ?' was observed to precipitate on defects such as dislocations and low-angle boundaries when a critical solute level in all ternary alloys was reached. The critical solute level was system dependent. Homogeneous nucleation of ?' occurred in Al-Si-Zr alloys. In Al-Zn-Zr alloys the shape of the ?' deviated from its usual spherical shape to a cube shape when the zinc level exceeds approximately 4 wt. %. When compared to other alloying element additions, small amounts of silicon (between 0.25 and 0.5 wt %) had the greatest influence on not only the recrystallization behavior of the alloy, but also the precipitation of ?'

  17. Zirconium alloy barrier having improved corrosion resistance

    International Nuclear Information System (INIS)

    A nuclear fuel element for use in the core of a nuclear reactor has a composite cladding container having a substrate and a dilute zirconium alloy liner bonded to the inside surface of the substrate. The dilute zirconium alloy liner forms about 1 to about 20 percent of the thickness of the cladding and is comprised of zirconium and a metal selected from the group consisting of iron, chromium, iron plus chromium, and copper. The dilute zirconium alloy liner shields the substrate from impurities or fission products from the nuclear fuel material and protects the substrate from stress corrosion and stress cracking. The dilute zirconium alloy liner displays greater corrosion resistance, especially to oxidation by hot water or steam than unalloyed zirconium. The substrate material is selected from conventional cladding materials, and preferably is a zirconium alloy. (author)

  18. Irradiation damage for zirconium-based alloys

    International Nuclear Information System (INIS)

    The objective of the project is to develop a fuel cladding tube for high burn-up. To get the objective, several Zr-based alloys were newly designed, manufactured, and evaluated of their out-of-pile performance on corrosion characteristics and mechanical properties. Some of them were applied for domestic and foreign patents. Especially, it is trying to manufacture sample products using the alloys that were already registered in the patient lists. However, the irradiation performance of the newly developed alloys was not verified yet although the out-of-pile tests of the alloys had been much carried out. It is hard to except the irradiation performance of cladding tubes since their microstructures are changed when they are irradiated. This report collects the information on the change of microstructures as well as irradiation performance of the Zr-based alloys. So, this report could be referred when the irradiation characteristics of the advanced cladding tubes are being tried

  19. Internal chlorination of Ni-Cr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Berztiss, D.; Hennesen, K.; Grabke, H.J. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany)

    1998-12-31

    In contrast to internal oxidation, sulfidation and carburization, very little information is available regarding internal chlorination, especially diffusion of chlorine in metallic alloys. This paper describes results of experiments on Ni-Cr alloys (<10 wt% Cr) exposed in an atmosphere containing radioactive HCl. The diffusion of chlorine in the alloy can be determined by measurement of residual {beta}-activity from the sample surface. Successively thin layers (0.5-10 {mu}m) of the alloy were removed by lapping and the surface activity was measured to obtain a depth profile. Both single and polycrystalline materials were tested. Through this work it should be determined if there is in fact solubility and diffusion of chlorine in Ni-based alloys as some authors have proposed or if the ingress of chlorine is mainly a grain boundary phenomenon. (orig.)

  20. Long - range foundry Al composite alloys

    Directory of Open Access Journals (Sweden)

    A. D. Mekhtiev

    2014-10-01

    Full Text Available The technology of obtaining nanostructural composite aluminum alloys consists in the plasma injection of refractory nanometric particles with simultaneous two-plane magnetic dynamic mixing of the melt. Particularly important in obtaining composite aluminum matrix alloys is the provision of the introduced particles wettability with the matrix melt for forming stable adhesive bonds. Nanostructured powder components can be considered not only to be a starting product for producing nanostructural composite aluminum alloys but as an independent commerce product. Nanostructural composite metal matrix alloys make one of the most prospective structural materials of the future, and liquid-phase technologies of their obtaining are the most competitive in producing products of nanostructural composite aluminum alloys in the industrial scale.