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Sample records for heat-resistant alloy hastelloy

  1. Creep properties with short period excessive loadings on a nickel-base heat-resistant alloy Hastelloy XR

    International Nuclear Information System (INIS)

    A series of constant load and temperature creep tests and constant temperature creep tests with short period excessive loadings was carried out on a nickel-base heat-resistant alloy Hastelloy XR, which was developed for applications in the High-Temperature Engineering Test Reactor (HTTR), at temperatures ranging from 900 to 1000degC in order to examine the creep behaviors of the alloy under such conditions. The excessive loading levels were the design stress intensity values Sm for Hastelloy XR indicated in the HTTR high-temperature structural design code. Five to six time excessive loadings did not cause significant changes of the minimum creep rate or the time to onset of tertiary creep. About ten time excessive loadings did not cause significant changes of the time to rupture or the rupture elongation. The above-mentioned results suggest that the design stress intensity values Sm for Hastelloy XR have been determined reasonably. (author)

  2. 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)

  3. 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)

  4. 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.)

  5. Corrosion properties of heat resistant alloys sheets in helium environment

    International Nuclear Information System (INIS)

    Corrosion behavior of heat resistant alloys sheets, which would be used for gas seal elements of an experimental VHTR in Japan, was investigated in a helium environment. Materials were Hastelloy X, Incoloy 800 and Incoloy MA 956. The test temperature range was 700--1,0000C, and the duration time was 1,000 h. Weight change of specimens of Hastelloy X and Incoloy 800 was approximately proportional to (time)sup(1/2), whereas that of Incoloy MA 956 was proportional to (time)sup(1/3). For protection of the alloys, two surface treatments, namely Al2O3 coating with CVD method, and preoxidation in air, were tried. At the Al2O3 coated specimens, oxidation and carburization were almost completely suppressed at a temperature range below 9000C, whereas some features of deterioration of protective film were observed at 1,0000C. Preoxidation in air reduced carburization to some extent, but little advantageous effect on oxidation was observed. Especially, oxide film of Incoloy 800 formed in air was not protective in helium environment. (author)

  6. 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

  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. Heat resistant magnesium alloys for automotive powertrain applications

    Energy Technology Data Exchange (ETDEWEB)

    Anyanwu, I.A.; Gokan, Y.; Nozawa, S.; Kamado, S.; Kojima, Y. [Dept. of Mechanical Engineering, Nagaoka Univ. of Technology, Nagaoka, Niigata (Japan); Takeda, S.; Ishida, T. [Ahresty Corp., Magnesium Products Mfg. Div., Tochigi (Japan)

    2003-07-01

    The suitability of new Mg-Zn-Al-Ca-RE alloys for automotive power train applications are evaluated. Zinc and aluminum contents of the alloys were systematically varied in order to determine alloys with a combination of good diecasting characteristics and high heat resistance. Addition of large amounts of zinc to the alloys results in the formation of intermetallic compounds that crystallize at lower temperatures relative to the matrix, and consequently, fluidity is improved, but hot tearing occurs during diecasting. However, one of the new alloys, Mg-0.5%Zn-6%Al-1%Ca-3%RE alloy is found to exhibit good diecastability and comparable heat resistance with the conventional aluminum alloy, ADC12 that is currently used for diecasting of automotive powertrain parts. (orig.)

  11. Study of creep and rupture behavior for a Ni-base heat resistant alloy improved for high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Creep-rupture tests of Hastelloy XR-II, a Ni-base heat resistant alloy modified for HTGR environment, were carried out in air and simulated HTGR helium at 700-1000degC up to 26,733 hours in the longest rupture time and about 207,000 hours in total testing times. The data was evaluated for high-temperature structural design using time-temperature parameter method. The boron content of Hastelloy XR-II (about 0.005 mass%) has been increased within the specification of Hastelloy XR. Experimental data and evaluated results were compared with the previous results for Hastelloy XR with low boron content (0.00028 mass%). Followings are a summary of the major findings. 1) Larger ductility is observed for Hastelloy XR-II than Hastelloy XR at higher temperatures. 2) The 100,000 h strength of Hastelloy XR-II is approximately twice of Hastelloy XR at 800 and 900degC. 3) The microstructural observation of creep-ruptured specimens showed a few macrocracks at 700degC, but round-type cavities at grain boundaries were pronounced with increasing temperatures. 4) With regard to the effect of the product forms, the creep-rupture strength of specimens sampled from tubes is slightly higher at 1000degC than that from plates. 5) The creep curves above 900degC were predominantly nonclassical. 6) The allowable stresses of So, Sm and St were computed using similar procedure employed for the previous data on Hastelloy XR with lower boron content. The significant increase in the So and St for Hastelloy XR-II over Hastelloy XR is recognized due to the improvement of both creep strength and creep-rupture ductility. (J.P.N.)

  12. Metal Dusting of Heat-Resistant Alloys

    OpenAIRE

    Al-Meshari, Abdulaziz I

    2008-01-01

    Metal dusting leads to disintegration of such alloys as iron and nickel-based into a “dust” of particulate metal, metal carbide, carbon, and/or oxide. It occurs in strongly carburising environments at 400-900°C. Literature survey has shown that alloys behave differently in metal dusting conditions based on their composition and the environment. Metal dusting mechanisms for iron and nickel-based alloys have been proposed but, nevertheless, have not been agreed upon and numerous modifications t...

  13. Cavitation erosion behavior of Hastelloy C-276 nickel-based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhen [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Han, Jiesheng; Lu, Jinjun [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Chen, Jianmin, E-mail: chenjm@lzb.ac.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2015-01-15

    Highlights: • Cavitation erosion behavior of Hastelloy C-276 was studied by ultrasonic apparatus. • The cavitation-induced precipitates formed in the eroded surface for Hastelloy C-276. • The selective cavitation erosion was found in Hastelloy C-276 alloy. - Abstract: The cavitation erosion behavior of Hastelloy C-276 alloy was investigated using an ultrasonic vibratory apparatus and compared with that of 316L stainless steel. The mean depth of erosion (MDE) and erosion rate (ER) curves vs. test time were attained for Hastelloy C-276 alloy. Morphology and microstructure evolution of the eroded surface were observed by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM) and the predominant erosion mechanism was also discussed. The results show that the MDE is about 1/6 times lower than that of the stainless steel after 9 h of testing. The incubation period of Hastelloy C-276 alloy is about 3 times longer than that of 316L stainless steel. The cavitation-induced nanometer-scaled precipitates were found in the local zones of the eroded surface for Hastelloy C-276. The selective cavitation erosion was found in Hastelloy C-276 alloy. The formation of nanometer-scaled precipitates in the eroded surface may play a significant role in the cavitation erosion resistance of Hastelloy C-276.

  14. Cavitation erosion behavior of Hastelloy C-276 nickel-based alloy

    International Nuclear Information System (INIS)

    Highlights: • Cavitation erosion behavior of Hastelloy C-276 was studied by ultrasonic apparatus. • The cavitation-induced precipitates formed in the eroded surface for Hastelloy C-276. • The selective cavitation erosion was found in Hastelloy C-276 alloy. - Abstract: The cavitation erosion behavior of Hastelloy C-276 alloy was investigated using an ultrasonic vibratory apparatus and compared with that of 316L stainless steel. The mean depth of erosion (MDE) and erosion rate (ER) curves vs. test time were attained for Hastelloy C-276 alloy. Morphology and microstructure evolution of the eroded surface were observed by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM) and the predominant erosion mechanism was also discussed. The results show that the MDE is about 1/6 times lower than that of the stainless steel after 9 h of testing. The incubation period of Hastelloy C-276 alloy is about 3 times longer than that of 316L stainless steel. The cavitation-induced nanometer-scaled precipitates were found in the local zones of the eroded surface for Hastelloy C-276. The selective cavitation erosion was found in Hastelloy C-276 alloy. The formation of nanometer-scaled precipitates in the eroded surface may play a significant role in the cavitation erosion resistance of Hastelloy C-276

  15. 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)

  16. Heat resisting coatings for molybdenum and alloys on its base

    International Nuclear Information System (INIS)

    Main trends in researches on heat resisting constructions of molybdenum and its alloys are formulated as follows: formation of surface silicide layers, alloyed with elements capable to form stable oxides, which have a low vapour pressure; formation of a coating-substrate barrier layer that prevents molybdenum dicilicide solution in a base metal and provides for gradual decrease of thermal stresses in silicide layer; designing protective coatings of refractory metal dicilicides and 4a group metal borides forming heterogeneous structure during oxidation; introduction of such additions into gaseous environment as to cease evaporation of protective films

  17. 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)

  18. 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)

  19. 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)

  20. Constitutive modeling of the visco-plastic response of Hastelloy-X and aluminum alloy 8009

    International Nuclear Information System (INIS)

    The viscoplastic behavior of advanced, high temperature, metallic alloys is characterized using the Bodner Partom unified constitutive model. Material parameters for both Hastelloy-X and Aluminum alloy 8009 are obtained for this model. The Bodner-Partom constitutive model is summarized, and a detailed approach for determining the model parameters from experimental data is reviewed. Experimental methods for obtaining the mechanical test data are described. Bodner-Partom model parameters are determined from data obtained in uniaxial, isothermal, monotonic tension or compression tests and isothermal creep tests. Model predictions from the parameters determined are generated and compared to experimental data

  1. Development of heat resistant Mg-Zn-Al-Ca-RE diecasting alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gokan, Y.; Suzuki, A.; Nozawa, S.; Anyanwu, I.A.; Kamado, S.; Kojima, Y. [Dept. of Mechanical Engineering, Nagaoka Univ. of Technology (Japan); Takeda, S.; Ishida, T. [Ahresty Corp., Magnesium Products Mfg. Div. (Japan)

    2003-07-01

    Diecast Mg-0.5{proportional_to}1%Zn-4{proportional_to}6%Al-1{proportional_to}2%Ca-1{proportional_to}3%RE alloys are evaluated in order to determine the influence of each alloying element on the casting characteristics and heat resistance of the alloys. The result shows that creep properties improve with a decrease in the amount of Zn and Al contents. However, high Al and Zn additions increase the fluidity of the alloys. Ca addition leads to the formation of an Al-Ca compound along the grain boundaries, and this helps to improve creep properties. However, the presence of large quantities of such compounds along the grain boundaries deteriorates the fluidity of the alloys and leads to hot cracking during diecasting. The creep properties of some of the investigated alloys are far superior to those of conventional heat resistant AE42 magnesium alloy. Furthermore, the diecasting characteristics of the new alloys are comparable to those of the best diecasting magnesium alloy, AZ91D, but their creep resistance is far superior to that of AZ91D alloy. (orig.)

  2. Newly developed heat resistant magnesium alloy by thixomolding

    Energy Technology Data Exchange (ETDEWEB)

    Tsukeda, T.; Uchida, R. [Research and Development Group, Magnesium Process Equipment and Products Div., Japan Steel Works, Ltd., Hiroshima (Japan); Suzuki, M.; Koike, J.; Maruyama, K. [Dept. of Materials Science, Graduate School of Engineering, Tohoku Univ., Sendai (Japan)

    2003-07-01

    Thixomolding of magnesium alloy is an environmentally friendly and safe casting process. This process is capable of near net shape casting from solid feedstock in a single step by injecting metallic slurry into a die cavity with high pressure at semi-solid or fully melted state. In the present work, we investigated the effects of the chemical composition on the creep resistance at elevated temperatures, the corrosion resistance at room temperature and the fluidity during thixomolding about the Mg-Al-Ca-Mm-Sr alloys. Obtained results are the following. (1) The creep resistance increased with increasing additional Ca or Sr content to AM60B. The effect of Ca was larger than that of Sr. The corrosion resistance decreased with increasing Ca content. (2) No significant differences of the corrosion and creep resistance were observed within the Al content of 4 to 8mass% in Mg-Al-3mass%Ca alloys. (3) More than 0.5mass% Mm addition to ACa63 was effective in the corrosion resistant to a certain extent without outstanding decrease of the creep resistance. Moreover, a practical corrosion rate was achieved by more than 0.01mass% Sr addition to ACaE6305. (4) A slight addition (0.01 mass%) of Sr to ACaE6305 was effective in improving the fluidity at a thin wall (1 mm) cavity with thixomolding. (orig.)

  3. 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.)

  4. Modification of heat resistant nickel alloys with disperse particles of refractory compounds

    International Nuclear Information System (INIS)

    The paper describes a technology for modifying heat resisting nickel alloys. The basic features of this technology are as follows. Low-dispersed refractory articles of modifiers (carbides, nitrides, carbonitrides) are introduced in the melt in the form of briqnettes. Melt temperature and permissible time of modifier insertion into the melt prior to costing are determined depending or alloy composition and objective to be achieved (grain refinement, improvement of strength or plasticity characteristics). Positive modification results are achieved for ZhS32, ZhS6U, XhS3DK alloys

  5. 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

  6. 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

  7. APT characterization of a high strength corrosion-resistant Ni-Cr-Mo HastelloyR C-22HSTM alloy

    International Nuclear Information System (INIS)

    Full text: The versatile C-type Ni-Cr-Mo alloys are well known for their corrosion resistance. These alloys have been used for many years in a wide variety of applications such as heat exchangers, scrubbers, reaction vessels, etc. as they exhibit significantly higher strength than most stainless steels. The strength of these alloys may be further increased by cold working. However, this mechanical processing approach limits the size and geometry of the final components. In addition, the high strength is lost in welds and associated heat affective zones. A new high strength corrosion-resistant alloy Ni-21% Cr-17% Mo, HASTELLOY C-22HS, has recently been developed to overcome these problems. This general purpose corrosion-resistant alloy may be used at temperatures of up to at least 600oC. Potential applications for this corrosion resistant high strength alloy include shafting, agitators, fan blades, hubs, springs, fasteners, valves, dies, rings and gaskets. The composition of the HASTELLOY C-22HS alloy used in this study was Ni, 20.6 wt. % Cr, 16.6% Mo, 1.1% Fe, 0.33% Al, 0.29% Mn, 0.11% Nb, 0.004% C and 0.004% B. The microstructure of the HASTELLOY C-22HS alloy was characterized in the age hardened condition - 16 h at 705oC, furnace cooled to 605oC, 32 h at 605oC and air cooled. The microstructure of this age hardened alloy was characterized with the Oak Ridge National Laboratory local electrode atom probe. The corrosion resistance of this alloy in HCl at 52oC and H2SO4 at 79oC was found to be similar to N06022 alloy and better than N07725 alloy. The yield strength of this alloy and N06022 were similar in the mill annealed condition. After the age hardening treatment, the 0.2% yield strength of the HASTELLOY C-22HS alloy increased from 222 to 542 MPa. The tensile elongation and the reduction in area of the age hardened alloy were 40% and 50%, respectively at room temperature and 48% and 66%, respectively at 595oC. Atom probe tomography of the HASTELLOY C-22HS alloy revealed that the microstructure consisted of fine (∼10-30 nm diameter) approximately spherical molybdenum-enriched Ni2(Cr, Mo) precipitates in an aluminum-, iron-, silicon-, and manganese-enriched matrix. The morphology of these precipitates was significantly finer than the lenticular Ni2(Cr, Mo) precipitates previously observed in a HAYNES 242 alloy. Ref. 1 (author)

  8. 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

  9. Studies on the permeation of hydrogen and tritium through heat resistant alloys

    International Nuclear Information System (INIS)

    At temperatures of 750 to 9500C the permeation of hydrogen through bare, heat resistant alloys was studied from 1 to 40 bar, the diffusion and permeation of tritium in the partial pressure range of 10-4 bar. Among the alloys studied were Incoloy 800, 800 H, 802, Inconel 617, 625, the Ni-based alloy Nimonic PE 13, and several non-commercial steels. At a given temperature, the permeation rate through samples with clean surfaces - substantially free of oxide films - was found to be proportional to the square root of the hydrogen pressure. The C and the Cr contents of the steels investigated proved to exert a strong influence on the activation energies of diffusion and permeation. In some alloys a reduction of the permeation rate was observed that can be attributed to the precipitation of intermetallic phases. In one case a decrease of the permeation rate occured during the measurements due to a phase transformation. (orig.)

  10. Relation of Engine Turbine-blade Life to Stress-rupture Properties of the Alloys, Stellite 21, Hastelloy B, Cast S-816, Forged S-816, X-40, Nimonic 80, Refractaloy 26, N-155, and Inconel X

    Science.gov (United States)

    Garrett, F B; Yaker, C

    1951-01-01

    An investigation was conducted to relate the engine performance of the heat-resistant alloys, Stellite 21, Hastelloy B, cast S-816, forged S-816, X-40, Nimonic 80, Refractory 26, N-155, and Iconel X to their stress-rupture properties. The engine test consisted of the repetition of a 20-minute cycle, 15 minutes at rated speed and approximately 5 minutes at idle. The results of the investigation indicated a direct correlation between stress-rupture life and blade life for the relatively low-strength alloys. The stress-rupture life and blade life for the relatively high-strength alloys did not correlate because of the effects of the vibratory stresses and the corrosive-gas atmosphere.

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

    International Nuclear Information System (INIS)

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

  12. High temperature behaviour of the alloy hastelloy B in a hydrogen chloride/water vapour atmosphere

    International Nuclear Information System (INIS)

    Specimens of the alloy Hastelloy B were tested at 600 and 7000C in an atmosphere of 21% HCl containing some free oxygen. The results are related to continuous weight-change measurements up to 100 h and long-term tests of 500 h. During the tests the samples lost weight initially at a constant rate which then decreased. An adherent oxide scale was developed. In the outer part of the scale formation of a compact layer, in which the impurities Si, Mn, Co and Cr became enriched, was observed. In the inner part MoO2 was formed, the growth of which was irregular as a result of phase transformations. This investigations was carried out in connection with a proposed thermochemical method of splitting water, involving the use of nuclear heat. (orig.)

  13. 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)

  14. About thermal cracking in joint at the heat-resistant alloys welding

    International Nuclear Information System (INIS)

    By welding heat-resistant nickel and cobalt alloys cracks are formed initially by dendrite boundaries in solid-liquid state inform of microcracks 20-100 ?m long, developing under impact of stretching tensions and joining into main crack both by the dendrite boundaries and by secondary boundaries. The mechanism of hot cracks formation was studied in the process of metallographic studies by the IMET-P methodology on working part of compact samples, subjected to deformation by velocities lower as critical ones

  15. Influence of titanium: aluminum ratio in heat-resistant nickel alloys on their resistance to high-temperature salt corrosion

    International Nuclear Information System (INIS)

    This paper discusses how the ratio of titanium to aluminum in the range from zero to four with a total content of 2-8% influences the resistance of heat-resistant nickel-based alloys to sulfate and chloride melts. When the Ti/Al ratio lies between zero and one, there is marked weakening of sulfide corrosion, but this parameter has little influence on the resistance to chlorides. In order to obtain good mechanical properties and resistance to high-temperature corrosion, heat-resistant alloys should be alloyed with approximately equal amounts of titanium and aluminum

  16. 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

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

    OpenAIRE

    Ohnuma I.; Kainuma R.; Ishida K.

    2012-01-01

    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.%) po...

  18. 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

  19. 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

  20. Laser texturing of Hastelloy C276 alloy surface for improved hydrophobicity and friction coefficient

    Science.gov (United States)

    Yilbas, B. S.; Ali, H.

    2016-03-01

    Laser treatment of Hastelloy C276 alloy is carried out under the high pressure nitrogen assisting gas environment. Morphological and metallurgical changes in the laser treated layer are examined using the analytical tools including, scanning electron and atomic force microscopes, X-ray diffraction, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. Microhardness is measured and the residual stress formed in the laser treated surface is determined from the X-ray data. The hydrophibicity of the laser treated surface is assessed using the sessile drop method. Friction coefficient of the laser treated layer is obtained incorporating the micro-tribometer. It is found that closely spaced laser canning tracks create a self-annealing effect in the laser treated layer and lowers the thermal stress levels through modifying the cooling rates at the surface. A dense structure, consisting of fine size grains, enhances the microhardness of the surface. The residual stress formed at the surface is compressive and it is in the order of -800 MPa. Laser treatment improves the surface hydrophobicity significantly because of the formation of surface texture composing of micro/nano-pillars.

  1. 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

  2. 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.)

  3. 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

  4. Crevice Corrosion of hastelloy C-276 and Inconel-625 Alloys in Chloride Environment, Effect of Bulk Solution Environment

    International Nuclear Information System (INIS)

    Electrochemical techniques have been applied to study the crevice corrosion resistance of two nickel-based alloys *namely, hastelloy C-276 and Inconel-625 in acidified sodium chloride aerated solution (pH=3), in the temperature range 25-100 degree C. Cyclic polarization (where the potential is reversed at 1.0 V(SCE) was performed on the two alloys at 25,50 and 100 degree C in the same pH chloride solution. Both alloys were resistant to this type of attack at 25 degree C, and both alloys were severely attacked at 100 degree C. This was clearly reflected in the value of ?I in the hysteresis loop and also in the values of both Ecorr. and Eb. The electrochemical results were substantiated by SEM investigation. The findings were interpreted in terms of the effect of chromium and molybdenum contents on the passive film characteristics and the influence of pH during polarization. 7 figs

  5. 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...

  6. Characterization of grain boundaries by fractal geometry and creep-rupture properties of heat-resistant alloys

    International Nuclear Information System (INIS)

    There is a certain 'self-similarity' between the parts and the whole of a microstructure in metallic materials, although the microstructures are generally complicated and irregular in nature. Serrated grain boundaries which are composed of irregular ledges and steps are effective in improving the high-temperature strength of heat-resistent alloys. There are some differences in the 'degree' (ruggedness) among the grain boundaries in heat-resistant alloys, depending on alloy composition and heat treatments. In this study, serrated grain boundaries are characterized by estimating the fractal dimension, and the relation between the increase of the fractal dimension of grain boundaries and the improvement of creep-rupture properties by serrated grain boundaries is discussed. (orig.)

  7. Glow discharge mass spectrometric analysis of nickel-based heat-resisting alloys

    International Nuclear Information System (INIS)

    GD-MS analysis of nickel-based heat-resisting alloys has been performed using a VG 9000 glow discharge (GD) mass spectrometer. Concentrations of not only alloying elements (Al, Si, Ti, V, Cr, Mn, Fe, Co, Cu, Y, Nb, Mo and W) but also trace elements (B, C, Mg, P, S, Zn, Ga, As, Zr, Cd, Sn, Sb, Te, Pb and Bi) were successfully determined in disk shaped samples. The examination of spectral interference confirmed the following. The influence of manganese argide (55Mn40Ar+) on the ion beam intensity of 95Mo+ was negligible because manganese content of the alloys is usually less than 1 mass%. Mass spectra of 31P+ and 32S+ may be affected by the spectral interference of 62Ni2+ and 64Ni2+, respectively, due to the matrix element. However, these ion species were sufficiently separated at the mass resolution 5000 (m/?m, at 5% peak height) used in this study. Relative sensitivity factors (RSFs) were determined by analyzing standard reference materials: JAERI CRMs, a NIST SRM, a BS CRM, BCS CRMs and the alloys prepared in our Institute. The average RSF-values obtained for Ni=1 were 0.436 for Al, 0.826 for Si, 0.281 for Ti, 0.375 for V, 1.480 for Cr, 1.122 for Mn, 0.754 for Fe, 0.653 for Co, 3.321 for Cu, 0.303 for Y, 0.436 for Nb, 0.862 for Mo, 0.935 for Ta and 1.052 for W. The analytical accuracy (?d) obtained was comparable to that of FP-XRF analysis, except for chromium and iron determinations. Relative standard deviations (RSDs) of five replicate measurements were within about 2.5%, except for phosphorus (P; 0.003 mass%, RSD; 3.31%) and sulfur (S; 0.005 mass%, RSD; 3.08%). GD-MS analytical values for ODS MA6000 alloy were obtained using a RSF correction program, and the values were in good agreement with those obtained by FP-XRF and by chemical analysis (author)

  8. 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%.

  9. Regularities of phase composition and structure formation in intermetallide-strengthened heat-resistant titanium alloy under hydrogen addition

    International Nuclear Information System (INIS)

    The phase composition and structure of the Ti-9Al-1Mo-4Sn-3Zr (mas.%) heat resistant alloy under hydrogen addition are studied. It is shown, that hydrogen decreases the temperature of the ?+?(?2) ? ? transition by 220 deg C by its concentration up to 1.0 mas.%. The hydrogen effect on the change of the phase composition is similar top the effect of the traditional ?-stabilizing elements

  10. Using of phase diagrams of ternary systems of transition carbide-containing metals in developing heat resisting hard alloys

    International Nuclear Information System (INIS)

    Heat resisting hard alloys containing refractory carbides are studied for a possibility of their production with application of cast alloys whose disperse structure is formed during their cooling crystallization. With this aim it is very important to study phase diagrams, in particular within the crystallization range. Two types of cast hard alloys are considered: cast tungsten carbides (rhelit) and refractory eutectics (W-MIVC+ first of all). It is shown that success in studying the M-C and M-M-C phase diagrams promotes a wider use of molybdenum in hard alloys as a tungsten substitute production of multicomponent of the both types. Factors are discussed that determine the character of phase equilibria in these systems and physicochemical premises of a directed search for a composition of cast refractory wear resistant carbide-containing alloys (ternary and multicomponent)

  11. 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%.

  12. 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...

  13. 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.)

  14. 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

  15. 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

  16. 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...

  17. Variation of microstructures and mechanical properties of hot heading process of super heat resisting alloy Inconel 718

    International Nuclear Information System (INIS)

    Metal forming is the process changing shapes and mechanical properties of the workpiece without initial material reduction through plastic deformation. Above all, because of hot working carried out above recrystallization temperature can be generated large deformation with one blow, it can produce with forging complicated parts or heat resisting super alloy such as Inconel 718 has the worst forgeability. In this paper, we established optimal variation of hot heading process of the Inconel 718 used in heat resisting component and evaluated mechanical properties hot worked product. Die material is SKD61 and initial temperature is 300 .deg. C. Initial billet temperature and punch velocity changed, relatively. Friction coefficient is 0.3 as lubricated condition of hot working. CAE is carried out using DEFORM software before marking the tryout part, and it is manufactured 150 ton screw press with optimal condition. It is know that forming load was decreased according to decreasing punch velocity

  18. Helium dilution effect on hydrogen permeation in 316L stainless steel and nickel-base heat-resistant alloys

    International Nuclear Information System (INIS)

    Effects of inert-gas dilution on hydrogen permeation have been investigated in 316L stainless steel, Inconel 600, Inconel 750, Nimonic 80A and Hastelloy X at 1173 K and 1073 K, by employing a gas-flow system. We used gas mixtures of hydrogen and helium, whose hydrogen concentration ranged from 10-5 to 10-1. For the steady-state permeation, the dilution of hydrogen caused no anomalous effects and the permeation rate conformed to Sieverts' law. However, for the transient state, the hydrogen permeation was retarded by the dilution with helium. The retardation effect is discussed in terms of an adsorption model and explained by a decrease in sticking probability at the alloy surface with the dissociative adsorption of hydrogen. (orig.)

  19. Evaluation on materials performance of Hastelloy Alloy XR for HTTR uses. 3. Manufacture of filler metal and its weldability

    International Nuclear Information System (INIS)

    Weldability on Hastelloy Alloy XR base metals and filler metals for the High Temperature Engineering Test Reactor (HTTR) components was examined by means of chemical analysis of deposited metals, optical microscopy, hardness measurements, FISCO and bend test. All of the results obtained by each test showed favorable performance. In particular, in the bend test which is considered to be critical pass, the optimization of B and C contents in the filler metal resulted in low susceptibility to weld cracking. Therefore, it is concluded that the excellent performance of the filler metal used and the effectiveness of narrowing groove are confirmed, and there is no problem from the viewpoint of engineering with respect to HTTR application. (author)

  20. Evaluation on materials performance of hastelloy alloy XR for HTTR uses. 4. Tensile properties of base metals and welded joints

    International Nuclear Information System (INIS)

    Tensile properties due to thermal aging on Hastelloy Alloy XR base metals and welded joints were investigated as a series of evaluation test on the base metals and filler metals for the High Temperature Engineering Test Reactor (HTTR) components. Tensile test in air was performed at R.T. and then same temperatures as the thermal aging temperatures after the specimens were aged at 800, 900 and 1000degC for 1000hrs. In comparison with the previous data, the present results had no significant difference on the strength characteristics, and were in the previous data band on the ductility. Therefore, it is concluded that these base metals and filler metals for the HTTR components have excellent tensile properties. (author)

  1. Influence of the brazing parameters on microstructure and mechanical properties of brazed joints of Hastelloy B2 nickel base alloy

    International Nuclear Information System (INIS)

    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)

  2. 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

  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. 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

  5. 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.

  6. 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.)

  7. 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.)

  8. High temperature corrosion of heat-resisting alloys by borosilicate melts containing simulated high level nuclear wastes

    International Nuclear Information System (INIS)

    In connection with the development of vitrified solidification process of high level liquid wastes (HLLW) by metallic vessel, the high temperature corrosion of some heat-resisting alloys, such as stainless steel, Incoloy and Inconel, were investigated with the molten borosilicate glass containing simulated HLLW in the temperature range of 1,000--1,2000C for 3--50 days. The concentration distributions of various constituents in the vicinity of the interface between the glass and the various metals were determined by means of EPMA. In the case of stainless steel, the general corrosion of alloys was observed without a protective layer. But in the case of both of Incoloy and Inconel, a chromium oxide layer was consequently formed between the glass and the metal, giving a protective film against general corrosion of alloys. When a MgCr2O4 layer on the chromium oxide layer and the alumina in alloy were, furthermore, formed, the corrosion of alloys became extremely depressed. The growth rate of the layer was controlled by chromium diffusion in alloy. The values of the effective diffusion coefficients D tilde sub(Cr) were approximately 1x10-10cm2/s at 1,1050C. (author)

  9. Effect of yttrium on the oxide scale adherence of pre-oxidized silicon-containing heat-resistant alloy

    International Nuclear Information System (INIS)

    Highlights: → AE experiment shows yttrium has a beneficial effect on the pre-oxidized HP40 alloy. → Yttrium facilitates the formation of internal oxide after 10 h of oxidation. → Internal oxide changes the rupture behaviour of the oxide scale. → Twins form in the internal oxide and improve the binding strength of the scale. - Abstract: This paper investigates the effect of the rare earth element yttrium on the rupture behaviour of the oxide scale on the silicon-containing heat-resistant alloy during cooling. After 10 h of oxidation, yttrium is found to facilitate the formation of internal oxides (silica) at the scale-matrix interface. Due to the twinning observed by scanning transmission electron microscopy (STEM) in silica, the critical strain value for the scale failure can be dramatically improved, and the formation of cracks at the scale-matrix interface is inhibited.

  10. Low-cycle fatigue of Type 347 stainless steel and Hastelloy alloy X in hydrogen gas and in air at elevated temperatures

    Science.gov (United States)

    Jaske, C. E.; Rice, R. C.; Buchheit, R. D.; Roach, D. B.; Porfilio, T. L.

    1976-01-01

    An investigation was conducted to assess the low-cycle fatigue resistance of two alloys, Type 347 stainless steel and Hastelloy Alloy X, that were under consideration for use in nuclear-powered rocket vehicles. Constant-amplitude, strain-controlled fatigue tests were conducted under compressive strain cycling at a constant strain rate of 0.001/sec and at total axial strain ranges of 1.5, 3.0, and 5.0 %, in both laboratory-air and low-pressure hydrogen-gas environments at temperatures from 538 to 871 C. Specimens were obtained from three heats of Type 347 stainless steel bar and two heats of Hastelloy Alloy X. The tensile properties of each heat were determined at 21, 538, 649, and 760 C. The continuous cycling fatigue resistance was determined for each heat at temperatures of 538, 760, and 871 C. The Type 347 stainless steel exhibited equal or superior fatigue resistance to the Hastelloy Alloy X at all conditions of this study.

  11. 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.

  12. 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)

  13. 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...

  14. Evaluation on materials performance of Hastelloy Alloy XR for HTTR uses-5 (Creep properties of base metal and weldment in air)

    International Nuclear Information System (INIS)

    Creep properties of weldment made from Hastelloy Alloy XR base metals and filler metals for the High Temperature Engineering Test Reactor (HTTR) components were examined by means of creep and creep rupture tests at 900 and 950degC in air. The results obtained are as follows: creep rupture strength was nearly equal or higher than that of Hastelloy Alloy XR master curve and was much higher than design creep rupture strength [SR]. Furthermore, creep rupture strength and ductility of the present filler metal was in the data band in comparison with those of the previous filler metals. It is concluded from these reasons that this filler metal has fully favorable properties for HTTR uses. (author)

  15. 9-12% Cr heat resistant steels. Alloy design, TEM characterisation of microstructure evolution and creep response at 650 C

    Energy Technology Data Exchange (ETDEWEB)

    Rojas Jara, David

    2011-03-21

    This work was carried out aiming to design and characterise 9-12% Cr steels with tailormade microstructures for applications in fossil fuel fired power plants. The investigations concentrated in the design and characterisation of heat resistant steels for applications in high oxidising atmospheres (12% Cr) and 9% Cr alloys for components such as rotors (P91). ThermoCalc calculations showed to be a reliable tool for alloy development. The modeling also provided valuable information for the adjustment of the processing parameters (austenisation and tempering temperatures). Two 12% Cr heat resistant steels with a fine dispersion of nano precipitates were designed and produced supported by thermodynamic modeling (ThermoCalc). A detailed characterisation of the microstructure evolution at different creep times (100 MPa / 650 C / 8000 h) was carried out by scanning transmission electron microscopy (STEM). The results of the microstructure analysis were correlated with the mechanical properties in order to investigate the influence of different precipitates (especially M{sub 23}C{sub 6} carbides) on the creep strength of the alloys. Precipitation of Laves phase and Z-phase was observed after several hundred 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. The influence of hot-deformation and tempering temperature on the microstructure evolution on one of the designed 12% Cr alloys was studied during short-term creep at 80-250 MPa and 650 C. Quantitative determination of dislocation density and sub-grain size in the initial microstructure and after creep was investigated by STEM combined with the high-angle annular dark-field detector (HAADF). A correlation between microstructure evolution and creep response was established. All crept samples showed a significant increase of sub-grain size and a reduction of the dislocation density. Hot deformed samples showed better creep strength than non hot-deformed samples, due to homogenisation of the microstructure. The tempering temperature affected the dislocation density and the sub-grain sizes, influencing the creep behaviour. 9% Cr alloys were designed supported by ThermoCalc. Two sets of alloys were produced: 9% Cr alloys with 0.1 % C and 0.05% C and 9% Cr alloys containing ? 0.03% Ti again with 0.1% C and 0.05% C (always wt%). Microstructure investigations showed good agreement with the predicted phases of the thermodynamic modeling. The volume fraction of precipitated M{sub 23}C{sub 6} carbides is directly related to the carbon content of the alloys. Hardening of the Ti-containing alloys by precipitation of fine dispersed Ti-based MX particles was achieved. The precipitation of these carbides was limited to the austenisation and tempering treatment used. The microstructure evolution (sub-grain and particle size) during creep at 650 C / 100MPa was investigated by STEM-HAADF. The sub-grain size evolution and the coarsening of precipitates (MX carbonitrides, M{sub 23}C{sub 6} and Laves phase) were more pronounced for Ti-containing alloys. 9Cr alloys without Ti and with low carbon content presented the highest creep strength of all investigated alloys.

  16. 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.)

  17. New low alloy heat resistant ferritic steels T/P23 and T/P24 for power plant application

    International Nuclear Information System (INIS)

    Higher efficiencies and increasing requirements for reduced emissions can only be met by fossil fired power plants through a further increase of steam temperature and pressure. Material development has mainly been focussed on high heat resistant martensitic 9-12% Cr steels. Ensuring higher steam parameters, however, has also lead to increasing requirements for tube steels in water walls, which can no longer be fulfilled with standard low alloy ferritic steels like 13CrMo4-4 (T12). The paper describes the properties of the newly developed steels T23 and T24. It also will be shown that they can have benefits by using them as P23/P24 for piping, especially for the refurbishment of old plants

  18. 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

  19. 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.)

  20. Die-casting capabilities of heat resistant Mg-Al-Ca alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.M.; Park, B.K.; Jun, J.H.; Kim, K.T.; Jung, W.J. [Advanced Materials Development Center, Korea Inst. of Industrial Technology, Yeonsu-Ku, Incheon (Korea)

    2005-07-01

    Various amounts of Ca were added to AZ91D magnesium alloy, and their effects on the die-casting abilities were investigated. It was observed that fluidity as die filling ability tends to decrease by Ca additions except for about 2%Ca. This reduction of fluidity by Ca was more significant at high superheats probably due to the high affinity between Ca and oxygen. Contrary to expectation, hot cracking resistance was found to increase by Ca additions. High Ca alloys showed some die-sticking tendency. However, the tendency was not observed below 2%Ca. (orig.)

  1. Tensile deformation behavior of spray-deposited FVS0812 heat-resistant aluminum alloy sheet at elevated temperatures

    International Nuclear Information System (INIS)

    The tensile deformation behavior of spray deposited FVS0812 heat-resistant aluminum alloy sheet was studied by uniaxial tension tests at temperatures ranging from 250 deg. C to 450 deg. C and strain rates from 0.001 to 0.1 s-1. The associated fracture surfaces were examined by scanning electron microscopy (SEM). The results show that the degree of work-hardening increases with decreasing temperature, and exhibits a small decrease with increasing strain rate; the strain rate sensitivity exponent increases with increasing temperature. The flow stress increases with increasing strain rate but decreases with increasing temperature. The total elongations to fracture increase not only with increasing temperature, but also with increasing strain rate, which is in marked contrast with the normal inverse dependence of elongation on the strain rate exhibited by conventional aluminum alloy sheets. The SEM fracture analysis indicates that the dependence of elongation on the strain rate may be due to the presence of a transition from plastic instability at lower strain rates to stable deformation at higher strain rates for fine-grained materials produced by spray deposition

  2. 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)

  3. Phase stability of heat resistant nickel Ni-Al-Cr-W-Ta-Mo alloy single crystals

    International Nuclear Information System (INIS)

    A study into the microstructure and phase transition temperatures in casted single crystals of a nickel base Ni-Al-Cr-W-Ta-Mo system alloy was carried out. A concentration dependence of ?-phase volume fraction and a position of (?+?')/(?+?'+?) phase boundary in the system studied are analytically estimated. This estimation permits forecasting ?-phase precipitation under actual condition of monocrystal growth by directional crystallization. 13 refs.; 4 figs.; 3 tabs

  4. 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

  5. Effect of the Fine-Grained Structure on the Fatigue Properties of the Heat-Resistant Nickel-Iron Alloy Inconel 718

    Science.gov (United States)

    Mukhtarov, Sh. Kh.; Shakhov, R. V.

    2015-10-01

    It is well known that ultrafine-grained nickel alloys with average grain sizes d = 0.1-1 ?m possess improved hot workability and can be used for superplastic forming or rolling. However, microstructure refinement can worsen some performance characteristics of the alloy, for example, heat-resistant or fatigue properties. In the present work, fatigue characteristics of the fine-grained alloy Inconel 718 are investigated. Ultrafine-grained alloys with average grain sizes d = 0.1-1 ?m were manufactured by multiple forging with stage-by-stage deformation temperature decrease. During standard heat treatment of the alloy performed to obtain the desired properties, the ?-grain size was controlled by precipitations of ?-phase particles along the boundaries. Results of low-cycle fatigue tests of the fine-grained alloy at room and elevated temperatures are compared with the properties of the coarse-grained alloy.

  6. ?????-?????????? ?????????? ???????????? ???????? ?? ???????? ??????? ??? ?? ??????????? ????????? ??????? 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.

  7. 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

  8. 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.

  9. High temperature diffusion induced liquid phase joining of a heat resistant alloy

    International Nuclear Information System (INIS)

    Transient liquid phase bonding (TLP) of a nickel base superalloy, Waspaloy, was performed to study the influence of holding time and temperature on the joint microstructure. Insufficient holding time for complete isothermal solidification of liquated insert caused formation of eutectic-type microconstituent along the joint centerline region in the alloy. In agreement with prediction by conventional TLP diffusion models, an increase in bonding temperature for a constant gap size, resulted in decrease in the time, tf, required to form a eutectic-free joint by complete isothermal solidification. However, a significant deviation from these models was observed in specimens bonded at and above 1175 deg. C. A reduction in isothermal solidification rate with increased temperature was observed in these specimens, such that a eutectic-free joint could not be achieved by holding for a time period that produced complete isothermal solidification at lower temperatures. Boron-rich particles were observed within the eutectic that formed in the joints prepared at the higher temperatures. An overriding effect of decrease in boron solubility relative to increase in its diffusivity with increase in temperature, is a plausible important factor responsible for the reduction in isothermal solidification rate at the higher bonding temperatures

  10. 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 1000 C 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 boron content level of the alloy. The modified rule successfully predicts the creep rupture life under the test conditions from 1000 to 900 C. The trend observed in the tests from 900 to 1000 C can be qualitatively explained by the mechanism that the oxide film which is formed during the prior exposure to 900 C plays the role of the protective barrier against the boron dissipation into the environment. (orig.)

  11. 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)

  12. Evaluation on materials performance of Hastelloy Alloy XR for the High Temperature Engineering Test reactor components. Weldability and high temperature strength properties

    International Nuclear Information System (INIS)

    Weldability and high temperature strength properties of Hastelloy Alloy XR were investigated in order to evaluate the materials performance of base metal and filler metal for the High Temperature Engineering Test Reactor (HTTR) uses. The weldability was examined by means of the chemical analysis in the deposited metals, optical microscopy, FISCO test, hardness measurements and bend test. The high temperature strength properties were investigated through tensile tests at R.T., 800, 900 and 950degC in air, and creep and creep rupture tests at 900 and 950degC in air. The results obtained by each test showed favorable performance. In particular, the bend test which is considered to be critical pass demonstrated low susceptibility to weld cracking through the optimization of B and C contents in the filler metal and by narrowing the groove. Creep rupture strength was nearly equal or higher than those of Hastelloy Alloy XR master curve and was much higher than design creep rupture strength [SR]. Therefore, it is concluded that weldability, tensile and creep properties with these base metals and filler metals for the HTTR components are entirely satisfactory. (author)

  13. Changes In Mechanical Properties Of Heat Resisting Alloy For A Satellite Propulsion System After A Nitriding Process

    Science.gov (United States)

    Kagawa, Hideshi; Fujii, Go; Kajiwara, Kenichi; Kuroda, Daisuke; Suzuki, Takuya; Yamabe-Mitarai, Yoko; Murakami, Hideyuki; Ono, Yoshinori

    2012-07-01

    Haynes25 (L-605) is a common heat resistant alloy used in mono-propellant structures and screen materials for catalyst beds. The lifetime requirements for thrusters have expanded dramatically after studies conducted in the 1970s on mono-propellant materials used to extend the service life. The material design had long remained unchanged, and the L-605 was still used as thruster material due to its good heritage. However, some important incidents involving degradation were found during the test-unit break-up inspection following the thruster life tests. The Japanese research team focused on the L-605 degradations found on the catalyst bed screen mesh used for mono-propellant thruster and analysed the surface of the wire material and the cross- section of the wire screen mesh used in the life tests. The investigation showed that the degradation was caused by nitriding L-605 component elements. The team suggested that the brittle fracture was attributable to tungsten (W) carbides, which formed primarily in the grain boundaries, and chromium (Cr) nitride, which formed mainly in the parts in contact with the hot firing gas. The team also suggested the installation of a platinum coating on the material surface as a countermeasure L-605 nitric degradation. Inconel 625 is now selected as a mono-propellant structure material due to its marginal raw material characters and cost. The team believes that Inconel 625 does not form W carbides since it contains no tungsten component, but does contain Cr and Fe, which form nitrides easily. Therefore, the team agreed that for the Inconel 625, there was a need to evaluate changes in the microstructure and mechanical properties following exposure to hot nitrogen gases. This paper will describe these changes of Inconel 625.

  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. 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.)

  16. 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.

  17. 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.)

  18. Effect of crystallization character of a casting nickel alloy type ZhS6 on its heat resistance

    International Nuclear Information System (INIS)

    Results of studies in long-term strength and ductility are presented for a ZhS6U casting alloy with an equiaxial and directed structure. It is established that directed crystallization of the alloy raises its strength characteristics

  19. On the mechanism of seandium influence on strength and heat resistance increase in Al-Mg alloys

    International Nuclear Information System (INIS)

    An attempt is made to study the strengthening nature in the Al-Ng-Sc alloy system. The problems of the temperature stability of the non-crystallized structure of the Al-6.5% Mg alloy and the nature of secondary extractions in these alloys caused by scandium presence, are studied. The alteration of the fluidity limit of the Al-6.5% Mg-Se alloys depending on the annealing temperature for various types of intermediate products is shown. Doping of the Al-6.5% Mg alloy with scandium brings about a considerable increase of strength properties, as a result of formation of the ScAl3 phase

  20. Creep property of hastelloy X and incoloy 800 in a helium environment

    International Nuclear Information System (INIS)

    To clarify the mechanism of the effect of helium environment on the creep properties of heat resistant alloys, relations of creep curves to the surface finish of test specimens, the development of creep cracks and oxidation kinetics etc. have been examined. Incoloy 800 at the temperature of 7500C indicates scarecely any environmental effect within the range of primary and secondary creep zones. Enhancement in the creep rate is noticed, however, at the tertiary creep zone under the helium environment. This finding is correlated to the fact that the crack, once initiated on the surface of the test specimen, propagates more easily because of the less oxidation under the helium environment. Importance of process control shall be emphasized for the manufacture of Hastelloy X since it has become clear that the effect of grain size on the creep strength is more pronounced than that of environment. (author)

  1. Control method of purification system of helium coolant for suppressing decarburization of heat-resistant alloy used in very high temperature gas cooling reactors

    International Nuclear Information System (INIS)

    It is important to control the chemistry of the helium coolant used in high-temperature gas-cooled reactors (HTGRs). The effect of a decarburizing environment on the creep rupture properties tends to decrease the creep rupture life of the heat-resistant alloy used in heat exchangers. In this paper, we describe an active control method for the concentration of impurities using the existing helium purification system, which consists of a helium heater, a copper oxide trap (CuOT), a molecular sieve trap, a cold charcoal trap, and a bypass line. Analysis showed that the efficiency control of CuOT is effective in improving the decarburizing atmosphere. The efficiency control of CuOT increases the concentrations of carbon monoxide and hydrogen. It was found that both the enrichment of carbon monoxide suggested in previous studies and the enrichment of hydrogen are also effective in forming the carburizing atmosphere. (author)

  2. Corrosion performance of heat resistant alloys in Na{sub 2}SO{sub 4}-V{sub 2}O{sub 5} molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Rodriguez, J.G. [Universidad Autonoma del Estado de Morelos, FCQI-CIICAP, Av. Universidad 1001, Col. Chamilpa, 62210-Cuernavaca, Mor. (Mexico)]. E-mail: ggonzalez@uaem.mx; Haro, S. [Universidad Autonoma de Zacatecas, Zacatecas (Mexico); Martinez-Villafane, A. [CIMAV, Miguel de Cervantes 120, Complejo Ind. Chih., Chihuahua (Mexico); Salinas-Bravo, V.M. [Instituto de Investigaciones Electricas, Cuernavaca, Mor. (Mexico); Porcayo-Calderon, J. [Instituto de Investigaciones Electricas, Cuernavaca, Mor. (Mexico)

    2006-11-05

    The corrosion resistant of three heat resistant alloys in molten vanadium pentoxide (V{sub 2}O{sub 5}), sodium sulfate (Na{sub 2}SO{sub 4}) and 80(mol%) V{sub 2}O{sub 5}-20Na{sub 2}SO{sub 4} has been evaluated using the weight loss technique. Materials included Fe-25Cr-35Ni-0.45C, Fe-35Cr-45Ni with 0.12 and 0.45C alloys. Temperatures included 600, 700 and 800 deg. C for V{sub 2}O{sub 5} and the 80V{sub 2}O{sub 5}-20Na{sub 2}SO{sub 4} mixture, and 800, 900 and 1000 deg. C for Na{sub 2}SO{sub 4}. The tests were supplemented by detailed electronic microscopy and microanalysis studies. In all cases, the least resistant alloy was the Fe-25Cr-35Ni-0.45C one whereas the most resistant was the Fe-35Cr-45Ni-0.12C one. The results are discussed in terms of the acidic dissolution of the external protective Cr{sub 2}O{sub 3}, Al{sub 2}O{sub 3} and SiO{sub 2} layers, by the salts and internal sulfidation.

  3. Chloride corrosion resistance of EhP539 and EhP99 heat resistant nickel alloys

    International Nuclear Information System (INIS)

    The effect of temperature and time on chloride corrosion resistance in the ternary eutectics (MgCl2-KCl-NaCl) of industrial alloys on the EhP539 and EhP99 nickel basis is studied. It is shown, that the corrosion of the above alloys at the temperature of 500-900 grad C has primarily intercrystalline character and proceeds by two-three orders faster as compared to usual high-temperature oxidation

  4. Effect of reactor irradiation on heat resistance of high nickel alloys of 03Kh20N45M4 type

    Energy Technology Data Exchange (ETDEWEB)

    Kiselevskij, V.N.; Kovalev, V.V.; Parshin, A.M.; Yaroshevich, V.D.; Kozhevnikov, O.A.; Lapin, A.N. (AN Ukrainskoj SSR, Kiev. Inst. Problem Prochnosti)

    1983-07-01

    The results are presented for intra-reactor studies of creep, long-term strength and plasticity of two modifications of 03Kh20N45M4 alloys in a 823-1023 K temperature range. The obtained characteristics are compared with the data for 0Kh16N15M3B steel. It is shown that the alloys possess higher characteristics of high-temperature strength as compared with the steel.

  5. Characterization of oxide layers of heat-resisting alloys in oxidizing and oxidizing/sulfidizing atmospheres by deuterium permeation measurement

    International Nuclear Information System (INIS)

    Deuterium permeation measurements are suitable to characterize the integrity of layers, which are preoxidized or in-situ oxidized on high temperature alloys. The permeation through metal alloys with a growing oxidized layer is described by a model with a time dependence of the permeation flux related to the growth of the oxide layer. The behaviour of the layers, which are oxidized at different oxidizing atmospheres, are investigated in this work. By permeation test, parabolic rate constants, impeding factors, as well as permeability, diffusivity and the solubility of deuterium for the oxide layers are obtained. The measurement are continued in sulfidizing atmosphere for testing such layers as corrosion barrier. In correlation with microstructural post examinations it is found that permeation measurement can be utilized as a method for investigating high-temperature corrosion. (orig.)

  6. Characterization of grain boundaries by fractal geometry and creep-rupture properties of heat-resistant alloys. [21-4N, HS-21, L-605, Inconel X-750, Inconel 751

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Manabu; Iizuka, Hiroshi (Akita Univ. (Japan). Dept. of Mechanical Engineering for Production)

    1991-06-01

    There is a certain 'self-similarity' between the parts and the whole of a microstructure in metallic materials, although the microstructures are generally complicated and irregular in nature. Serrated grain boundaries which are composed of irregular ledges and steps are effective in improving the high-temperature strength of heat-resistent alloys. There are some differences in the 'degree' (ruggedness) among the grain boundaries in heat-resistant alloys, depending on alloy composition and heat treatments. In this study, serrated grain boundaries are characterized by estimating the fractal dimension, and the relation between the increase of the fractal dimension of grain boundaries and the improvement of creep-rupture properties by serrated grain boundaries is discussed. (orig.).

  7. Effect of mechanical surface treatment on oxidation and carburization of some austenitic heat resisting alloys in the simulated HTGR helium environment

    International Nuclear Information System (INIS)

    Influence of mechanical surface finishing on corrosion was studied with some austenitic heat resisting alloys exposed to the simulated HTGR helium environment. The exposure tests were made at 900 and 10000C for 500 and 1500h. Contrary to the prediction based on the trend of some conventional experimental results on the oxidation of cold worked material at comparatively low temperatures, severe cold working, e.g. shot-blasting, was found to accelerate oxidation and carburization. Although, in some cases, moderate surface grinding showed results almost comparable to the surface abraded with fine emery papers, most mechanical surface finishing were recognized as to promote oxidation and carburization at 900 and 10000C in the simulated HTGR helium. The oxide film formed on the ground or shot-blasted specimen tended to spall more easily during cooling after isothermal exposure at 10000C. Based on the metallographic observation mechanisms of the acceleration of oxidation and carburization was discussed. The surface cold work was considered to cause not only enhanced chromium diffusion to the surface but also considerable degree of inhomogeneity of the degree of working in the microscopic scale, resulting in rather rapid oxide build-up and spallation. Some of the surface finishing in practice with severe cold working, thus, were concluded to be harmful to the integrity of HTGR structural components. (author)

  8. 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)

  9. 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)

  10. Tungsten powder alloys with carbide hardening as materials for reinforcing fibres in heat resistant composite materials. Communication 1.Manufacture of powder tungsten carbide-hardened alloys

    International Nuclear Information System (INIS)

    Factors affecting the possibility of stabilization in tungsten powder alloys of high-melting hardening interstitial phases (carbides, borides and nitrides of 4 group metals) are considered: presence of oxygen from the atmosphere and that asorbed on the surface of powder particles within W-MeC(MeB2, MeN) system; temperature of sintering occurrence of interstitial elements or phases interacting with oxygen more actively that the phase (HfC) that should be stabilized in the system. Measures allowing to prepare tungsten powder alloys using standard process equipment are suggested

  11. 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.)

  12. 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)

  13. 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

  14. 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.

  15. 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

  16. 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

  17. Corrosion of Inconel-625, Hastelloy-X280 and Incoloy-800 in 550 - 750°C superheated steam. Influence of alloy heat treatment, surface treatment, steam temperature and steam velocity. Part I: Results up to 6000 hours exposure time. RCN Report

    International Nuclear Information System (INIS)

    Sheet samples of Inconel-625, Hastelloy-X280 and Incoloy-800 were tested, in the solution annealed and in the solution annealed + 20% cold worked + 800°C tempered condition, in steam with a velocity of 5 m/sec. at 550, 650 and 750°C and in steam with a volocity of 15 and 85 m/sec. at 550°C. At 550°C and 750°C the samples were tested in the heat treated, annealed or tempered and the heat treated + electropolished condition. At 650°C moreover as heat treated + ground and pickled samples were tested. Post-corrosion sample investigations involved measurement of the adherent oxide thickness, the total amount of corroded metal, the metal loss to system, and the metallographic and microprobe investigation of the adherent oxide film and adjacent diffusion disturbed alloy layer. The results obtained up to 6000 hours exposure time showed that the surface treatment has a decisive influence on the corrosion behaviour of all three alloys tested. The differences in the corrosion data for the two heat treatment conditions are small. The influence of the steam velocity, as tested at 550°C, on the initial corrosion rate was surprisingly high, while the long-term linear corrosion rates are only slightly influenced by the gas velocity. In general the linear corrosion rates were low, 1-5 mg/dm2 month, and not consistently affected by the test-temperature. The metal loss to system values were 2 <15 mg/dm2 in the low velocity steam at all three test temperatures and <30 mg/dm2 in the high velocity steam at 550°C. The metallographic and microprobe examinations revealed no remarkable results, as compared with the results of analogous tests reported in literature. (author)

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. Kinetics of evaporation and ablation of goods made from heat-resistant alloys with protective coatings under irradiation with high-power ion beams

    International Nuclear Information System (INIS)

    The kinetics of ablation of the surface layers of the specimens and gas-turbine engine (GTE) vanes made from the Ti- and Ni-based alloys with erosion-resistant coatings under the action of power pulse ion beams (PPIB) at different pulse current density has been studied. The basics of ecology-pure ion-beam technologies of repairing GTE vanes with different protective coatings are developed. It is shown that a powerful ion beam of millimicrosecond duration is quite an efficient tool for repairing compressor blades and a turbine with protective coatings. PPIB application makes it possible to remove the surface layers of 0.04 (TiSiB) up to 1 μm (ZrN) thickness for one impulse

  4. Application of Hastelloy X in gas-cooled reactor systems

    International Nuclear Information System (INIS)

    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

  5. 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.

  6. 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

  7. 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

  8. A Study on the High Temperature Oxidation Behavior of Hastelloy X and Inconel 713C

    International Nuclear Information System (INIS)

    In order to preserve surface stability and mechanical properties of the substrate materials, coatings are applied to the alloy surfaces for the high temperature applications. Even with the application of coating, the substrate materials must also have its own resistance to the high temperature oxidation because the substrate may be catastrophically degraded when coatings are failed. In this research, Ni-base superalloys, IN 713C and Hastelloy X for the substrate materials of coatings, were examined by the isothermal and cyclic oxidation experiments. In the isothermal oxidation experiments, the dominant protective oxide scale of Hastelloy X was Cr2O3 and that of IN 713C was the Al-rich oxide scale. Both alloys formed protective oxide scales, and showed good isothermal oxidation resistance but IN 713C showed better oxidation resistance than Hastelloy X owing to the formation of Al-rich oxide scales. Also for cyclic oxidation experiments, due to the favorable adhesion between the substrate and oxide scales, IN 713C having thin Al-rich oxide scales showed better oxidation resistance than Hastelloy X throughout the temperature ranges tested. Comparing these two alloys IN 713C had better oxidation resistance but both alloys showed good oxidation resistance up to 1000 .deg. C

  9. 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.)

  10. Heat-resistant fungi in the soil.

    Science.gov (United States)

    Jesenská, Z; Piecková, E; Bernát, D

    1992-07-01

    The occurrence of heat-resistant fungi has been demonstrated in samples of soil from the Slovak Republic. The heat-resistant species isolated were Byssochlamys nivea, Dichotomomyces cejpii, Eupenicillium baarnense, Neosartorya fischeri, Talaromyces avellaneus, Tal. bacillisporus, Tal. emersonii, Tal. flavus, Tal. trachyspermus, Tal. wortmanii, Botryotrichum piluliferum, Gilmaniella humicola and Nodulisporium sp. Some of them were isolated for the first time from Czechoslovakian soil. For the various soil samples examined, the occurrence of heat-resistant fungi varied qualitatively and quantitatively. Further research is needed to identify conditions affecting the occurrence of heat-resistant fungi in soil. PMID:1445767

  11. The oxidation behaviour of heat resisting metallic fibres

    International Nuclear Information System (INIS)

    The behaviour of 22 ?m diameter alloy fibres of Type 310 stainless steel, Hastelloy X, Inconel 601 and Fecralloy has been studied at 6000C in combustion gases with and without HCl addition. Chromia-forming alloys exhibited higher rates of attack than would have been expected from a consideration of the properties of the bulk material whereas normal rates of attack were observed for alumina-forming alloys. The addition of HCl to the combustion gases increased rates of attack for all alloys and generally this was associated with increased sulphur in the oxide layer. The results are discussed with reference to the unusual geometry of the samples, and it is suggested that the direction of motion of the ions in the growing oxide layer is an important factor governing its protective nature. Alloy depletion effects were also noted, particularly for some Fecralloy samples which were pre-oxidized before exposure, and this may cause eventual failure of the protective oxide. A common feature of the oxidation of iron-chromium alloys is the partitioning of elements in the scale; this was especially marked for the Type 310 stainless steel samples exposed in this work and a stress-assisted diffusion process is proposed to explain this effect. (author)

  12. 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

  13. 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.

  14. Heat resistant fungi isolated from soil.

    Science.gov (United States)

    Piecková, E; Bernát, D; Jesenská, Z

    1994-06-01

    The Thermal death time values (TDT) were estimated for Dichotomomyces cejpii, Gilmaniella humicola, Talaromyces avellaneus and Talaromyces bacillisporus isolated from soil. TDT values were compared with the TDT values of the known heat-resistant species, Byssochlamys nivea, Neosartorya fischeri and Talaromyces flavus. All species studied showed considerable heat resistance. The most resistant species Talaromyces avellaneus (172 cfu, initial concentration) of the isolates with unknown heat resistance withstood 90 degrees C for 10 min. Byssochlamys nivea appeared to be the most sensitive species under our experimental conditions. PMID:7986681

  15. 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.

  16. 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...

  17. Preliminary Assessment of Oxidation Pretreated Hastelloy as Hydrocarbon Steam Reforming Catalyst

    OpenAIRE

    de la Rama, S. R.; Kawai, S; Yamada, H.; Tagawa, T.

    2014-01-01

    The potential of oxidation pretreated Hastelloy tube as a hydrocarbon steam reforming catalyst was assessed using tetradecane, toluene, and naphthalene as model compounds. Surface characterization showed that Fe2O3, Cr2O3, MoO3, and NiO were formed on the surface of the alloy after oxidation at 1000°C for 2 hours. Catalytic evaluation showed good activity and stability with tetradecane while lower activity with increased rate of carbon formation was observed with naphthalene.

  18. 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.

  19. Air oxidation and seawater corrosion of Hastelloy S and Hastelloy C-4

    Energy Technology Data Exchange (ETDEWEB)

    Fullam, H.T.

    1980-03-01

    A program is currently under way at the Pacific Northwest Laboratory (PNL) to develop the data and technology needed to permit the licensing of /sup 90/SrF/sub 2/ as a radioisotope heat source fuel for terrestrial applications. The WESF /sup 90/SrF/sub 2/ storage capsule consists of a Hastelloy C-276 inner capsule (2 in. I.D. x 19 in. long) and a 316L stainless steel outer capsule (2-3/8 in. I.D. x 20 in. long). Preliminary experimental tests and theoretical calculations show that the WESF storage capsule is incapable of meeting current licensing requirements for heat sources that are to be used for terrestrial applications. Therefore, the DOE decision was to develop a new heat source design that would retain the existing WESF Hastelloy C-276 inner capsule and replace the current WESF outer capsule with a new outer capsule capable of meeting current licensing requirements. Based on a number of factors, Hastelloy S was selected as the outer capsule material. Hastelloy C-4 was selected as a backup material in case the Hastelloy S had to be rejected for any reason. This report summarizes the results of studies carried out to determine the effects of both air oxidation at heat source operating temperatures and seawater corrosion on the tensile properties of the outer capsule materials.

  20. Air oxidation and seawater corrosion of Hastelloy S and Hastelloy C-4

    International Nuclear Information System (INIS)

    A program is currently under way at the Pacific Northwest Laboratory (PNL) to develop the data and technology needed to permit the licensing of 90SrF2 as a radioisotope heat source fuel for terrestrial applications. The WESF 90SrF2 storage capsule consists of a Hastelloy C-276 inner capsule (2 in. I.D. x 19 in. long) and a 316L stainless steel outer capsule (2-3/8 in. I.D. x 20 in. long). Preliminary experimental tests and theoretical calculations show that the WESF storage capsule is incapable of meeting current licensing requirements for heat sources that are to be used for terrestrial applications. Therefore, the DOE decision was to develop a new heat source design that would retain the existing WESF Hastelloy C-276 inner capsule and replace the current WESF outer capsule with a new outer capsule capable of meeting current licensing requirements. Based on a number of factors, Hastelloy S was selected as the outer capsule material. Hastelloy C-4 was selected as a backup material in case the Hastelloy S had to be rejected for any reason. This report summarizes the results of studies carried out to determine the effects of both air oxidation at heat source operating temperatures and seawater corrosion on the tensile properties of the outer capsule materials

  1. 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.

  2. 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.)

  3. 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.

  4. On the estimation of long term creep rupture strength of Hastelloy XR in HTGR helium environment

    International Nuclear Information System (INIS)

    Using special type specimens, which contained multiple diameters with step within the gauge portion in one piece, creep rupture and the associated surface phenomena were examined with special emphasis placed on the effect of oxidation and carburization on the creep and rupture properties. Based on the results obtained, creep rupture strength of alloy XR at 800 to 10000C under the influence of impure helium environment has been critically discussed. Oxidation kinetics of the alloy in the helium environment was not seen to be accelerated by the in creep deformation appreciably within the range of conditions tested. The duplex-structure oxide film formed on Hastelloy alloy XR, being composed of MnCr2O4 spinel type oxide and Cr2O3, maintained its function up to the creep strain of a few per cent, and the degree of carburization occurred during the steady creep stage was not affected by the deformation. After the onset of accelerating creep and the resultant initiation of the surface cracks, however, the continuity of the oxide film was lost to cause severe carburization. Parallel to those tests, the same material was pack-carburized up to the carbon content of about 0.4 wt%. The treatment caused decrease in both rupture elongation and strength. Based on the observed facts, a concept of conservatism to be included in the predictive evaluation was proposed in the estimation of the long term creep rupture strength of Hastelloy alloy XR in the HTGR impure helium environment. It is concluded that the 50% value of the rupture life in inert environment is the presently most conservative rupture life of Hastelloy alloy XR in HTGR helium environment. (author)

  5. 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.)

  6. Investigation of the creep behaviour of heat resistant gas turbine alloys. [Materials: Inconel 718, FSX 414, Udimet 500, IN-713C, IN-100, IN-738LC, IN-939, Nimonic 101

    Energy Technology Data Exchange (ETDEWEB)

    Kloos, K.H.; Granacher, J.; Bartsch, H.

    1986-06-01

    The high temperature deformation behaviour of typical investment cast materials and wrought alloys is measured in tensile tests, continuous and interrupted creep tests and annealing tests. In a special evaluation method the strain values determined in the different tests are combined. Examples for characteristic creep values and for creep equations are given.

  7. 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.

  8. Effect of Mn on oxidation resistance of hastelloy X in simulated VHTR helium environment

    International Nuclear Information System (INIS)

    Oxidation behavior of several heats of Ni-base alloy Hastelloy X with different Mn contents was studied. The exposure tests were made with impure helium at 10000C simulating a Very High Temperature Reactor (VHTR) coolant. Characterized by the selective oxidation of some limited number of chemically active minor elements in the alloy in the low potential oxidizing environment, the oxidation resistance was found to be controlled by factors unique to this system. Manganese in particular was shown to be a special element that formed a spinel oxide with Cr in the environment; its effect on kinetics of the surface reactions was studied. The addition of Mn up to 1.3% improve oxidation resistance of Hastelloy X, possibly due to the formation of the outer MnCr2O4 spinel oxide layer outside the inner Cr2O3 oxide layer. Based on the observed increase in the MnCr2O4/Cr2O3 thickness ratio with Mn content, a proposal was made in protecting the alloy by the optimum Mn addition. (author)

  9. Electrochemical impedance spectrometry using 316L steel, hastelloy, maraging, Inconel 600, Elgiloy, carbon steel, TiN and NiCr. Simulation in tritiated water. 2 volumes

    International Nuclear Information System (INIS)

    Polarization and electrochemical impedance spectrometry curves are presented and discussed. These curves make it possible to ascertain the corrosion domains and to compare the slow and fast kinetics (voltammetry) of different stainless steel alloys. These corrosion kinetics, the actual or simulated tritiated water redox potentials, and the corrosion potentials provide a classification of the steels studied here: 316L, Hastelloy, Maraging, Inconel 600, Elgiloy, carbon steel and TiN and NiCr deposits. From the results it can be concluded that Hastelloy and Elgiloy have the best corrosion resistance. (author). 49 refs., 695 figs., tabs

  10. Thermophysical Properties of Heat Resistant Shielding Material

    International Nuclear Information System (INIS)

    This project was aimed at determining thermal conductivity, specific heat and thermal expansion of a heat resistant shielding material for neutron absorption applications. These data are critical in predicting the structural integrity of the shielding under thermal cycling and mechanical load. The measurements of thermal conductivity and specific heat were conducted in air at five different temperatures (-31 F, 73.4 F, 140 F, 212 F and 302 F). The transient plane source (TPS) method was used in the tests. Thermal expansion tests were conducted using push rod dilatometry over the continuous range from -40 F (-40 C) to 302 F (150 C)

  11. 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.

  12. 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.

  13. 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.

  14. Thermal adhesion of heat-resistant materials in high temperature gas-cooled reactors and methods to prevent it

    International Nuclear Information System (INIS)

    High temperature gas-cooled reactors (HTGRs) have many high-temperature sliding or contacting parts. Generally these can be divided into contact between metal parts in each other and contact between metal and graphite. The authors set out to clarify adhesion behavior between metal and metal, and to acquire techniques that effectively prevent adherence of various heat-resistant materials in high temperature helium gas environments. Hastelloy X, Incoloy 800, Inconel 625 and Inconel 601 were investigated in the experiments. The obtained result shows that the ZrO2 coating using a plasma spray process is the most effective method to prevent adhesion of these materials at working temperatures in excess of 8000C (1,4700F). Subsequently the experimental results were actually applied in the design and fabrication of the Oarai Gas Loop 1 (OGL-1) and the High Temperature Gas Loop (HTGL) in the Japan Atomic Energy Research Institute. (author)

  15. Heat-resistant protective and special coatings

    International Nuclear Information System (INIS)

    The paper reviews heat-resistant protective and special coatings of practical uses. To protect the structures against chemical destruction in hot acid-alkaline solutions, chemically resistant coatings are developed. The best protective effect in such media is provided by silicate enamels. New potentialities in the field of enamel coatings were revealed recently in connection with the creation of glass-crystalline (sital) enamels. A separate type of metal protection is represented by glass lining. The heat-resistant coatings include metal-like and cermet coatings. Wear-resistant coatings protect machine parts against mechanical wear under various types of friction. Heat-insulating coatings protect structures against superheating and softening at elevated temperatures. The formation of weld-up on metal cast surfaces could be prevented by means of anti-weld-up coatings. Anti-tarring coatings are known which are capable of preventing tarring. Various types of sticking are eliminated by means of anti-adhesive coatings. Electrical insulation coatings occupy an important place in the modern engineering. The electroconducting coatings are of the opposite purpose. The investigations being carried out are based on the general scientific principles

  16. 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 850 and 9500C for 3000 h. Optical microscopy, scanning electron microscopy (SEM), 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. Aluminide coatings with chromium (HI-15) showed the lowest coating-substrate interface porosity and intermetallic phase growth. The presence of excess chromium in the HI-15-aluminide-coated Hastelloy X sample is believed to have compensated partially for the nickel loss by its diffusion into the nickel-depleted coating-substrate transition zone. None of the other coating additions had an obvious effect on the overall behavior of aluminide-coated Hastelloy X or Inconel 617 in the impure helium environment. The exterior of the aluminide coatings was not visually affected by the impure helium. Carbide precipitation below the coating-substrate interface, resulting from carbon ingress from the helium environment, was observed in uncoated control samples. Carburization of aluminide-coated substrates was less extensive than that of uncoated materials and was related to the degree of porosity at the coating-alloy interface. (Auth.)

  17. Optimization in Si content of hastelloy XR for oxidation resistance and oxide film adherence during oxidation in VHTR helium

    International Nuclear Information System (INIS)

    Oxidation behavior of several heats of modified Hastelloy alloy X, named Hastelloy XR, with different Si contents was examined in isothermal, thermal cycling exposure tests. The test environment was flowing helium at 10000C containing controlled amounts of impurities simulating the Very High Temperature gas-cooled Reactor (VHTR) coolant. Tests were made to determine an optimization rang of Si content for obtaining higher resistance to the oxidation and less oxide spallation in the service environment. Up to 1% content, increase of the Si caused decrease of the oxidation rate, while the oxide spallation in thermal cycling was a minimum in the range of about 0.2 to 0.4% Si. These two could be explained in formation and morphology of the SiO2 phase in the oxide and metal interface by metallographic observation and analysis. (author)

  18. 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

  19. Effect of cold work on creep properties of Hastelloy XR

    International Nuclear Information System (INIS)

    Creep tests of Hastelloy XR, in 10%, 20% cold worked or solution treated condition, were made at 800 at 1000degC for times up to about 2000 ks in order to investigate the effect of cold work on creep properties. The results obtained are as follows: (1) Below 950degC, creep rupture strength of 10% cold worked Hastelloy XR is beyond the value of solution treated one within this experimental condition. 950degC and cold work of 10% are the highest values experienced in an intermediate heat exchanger of the High Temperature Engineering Test Reactor(HTTR) under normal condition, respectively. (2) At 800 and 850degC, creep rupture time of 20% cold worked Hastelloy XR is longer than that of solution treated one. However, the effect disappears above 900degC. At 950 and 1000degC, it becomes shorter than that of solution treated Hastelloy XR. (3) Rupture elongation and reduction of area of cold worked Hastelloy XR are smaller than those of solution treated one. While these values of 10% or 20% cold worked material are lowest at 900degC, they recover considerably at 1000degC. (4) Minimum creep rate, ?m, of 10% or 20% cold worked Hastelloy XR is decreased by as much as a factor of 20 to 50 at 800 to 900degC. On the other hand, ?m of 10% or 20% cold worked material is increased at 1000degC. (5) From the results of microstructure observation of ruptured specimens, decrease in creep rupture strength of cold worked Hastelloy XR is interpreted in terms of extensive recrystallization which occurs during creep at 1000degC. (author)

  20. Heat resistant concrete (Rhine sand concrete)

    International Nuclear Information System (INIS)

    The heat resistant concrete has a fresh concrete density of at least 2300 kg/m3, a great strength in the temperature range 200 to 3000C, and is intended for prestressed concrete reactor pressure vessels, for nuclear reactors, particularly high temperature reactors. It consists of a quantity of hydraulic cement with water, concrete additives of quartz and flyash as additives and to delay solidification and concrete liquifier as additive. For a water cement value of 0.40, the quantity has a fine grain content of 29% of the additive. The flyash and finely divided quartz grain content causes a rise in strength in hydrothermal conditions, which counteracts the loss of strength due to temperature effects. (orig./PW)

  1. 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.

  2. 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.

  3. 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)

  4. 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

  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. 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)

  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. Refractory metal based alloys

    International Nuclear Information System (INIS)

    Given are the basic data, regarding the properties of the tungsten, molybdenum-, niobium- and tantalum-based alloys and the basic trends for the Use of these alloys. Shown are the possibilities to enhance the heat-resistant and strength properties of the metals throught alloying and to use the protective coatings

  11. Study on the heat-resistant EB curing composites

    International Nuclear Information System (INIS)

    There are many advantages in the EB-curing process of composites. Heat-resistant EB-curing composites could substitute for polyimide composites used in aeronautical engine. The effects of catalyst and dose on the cured resin were investigated. The heat-resistance of the resin cured by EB was evaluated by dynamic mechanical thermal analysis (DMTA). The experiment result shows that the mechanical property of the composites cured by EB could meet the needs of the aeronautical engine in 250degC. (author)

  12. Study on the heat-resistant EB curing composites

    Energy Technology Data Exchange (ETDEWEB)

    Bao Jianwen; Li Yang [Institute of Aeronautical Materials, Beijing (China); Li Fengmei [Institute of Low Energy Nuclear Physics, Beijing Normal Univ., Beijing (China)

    2000-03-01

    There are many advantages in the EB-curing process of composites. Heat-resistant EB-curing composites could substitute for polyimide composites used in aeronautical engine. The effects of catalyst and dose on the cured resin were investigated. The heat-resistance of the resin cured by EB was evaluated by dynamic mechanical thermal analysis (DMTA). The experiment result shows that the mechanical property of the composites cured by EB could meet the needs of the aeronautical engine in 250degC. (author)

  13. Inconel-600/T-111 alloy compatibility studies

    International Nuclear Information System (INIS)

    Oxidation resistant Hastelloy-C is the material presently used to clad a small radioisotopic heat source. Inconel-600 has properties and composition similar to Hastelloy-C and is under consideration as an alternate clad material. To serve this purpose, the material must be compatible with the underlying T-111 alloy strength member. Upon completion of compatibility studies, metallographic examination of the specimens revealed reaction zones that appeared to be influenced by time and temperature. The widths of the zones were determined by linear measurements from photomicrographs. These data were used to determine rate curves for the reaction at 1000, 1100, 12250C. The activation energy for the reaction was determined from these rate curves. The data for Inconel-600, when compared to previously accumulated data for Hastelloy-C, indicated that Inconel-600 can be substituted for Hastelloy-C and will pose no compatibility problem in the heat source

  14. Feasibility of EB Welded Hastelloy X and Combination of Refractory Metals

    Science.gov (United States)

    Martinez, Diana A.

    2004-01-01

    As NASA continues to expand its horizon, exploration and discovery creates the need of advancement in technology. The Jupiter Icy Moon Orbiter's (JIMO) mission to explore and document the outer surfaces, rate the possibility of holding potential life forms, etc. within the three moons (Callisto, Ganymede, and Europa) proves to be challenging. The orbiter itself consists of many sections including: the nuclear reactor and the power conversion system, the radiator panels, and the thrusters and antenna. The nuclear reactor serves as a power source, and if successfully developed, can operate for extended periods. During the duration of my tenure at NASA Glenn Research Center's (NASA GRC) Advanced Metallics Branch, I was assigned to assist Frank J. Ritzert on analyzing the feasibility of the Electron Beam Welded Hastelloy X (HX), a nickel-based superalloy, to Niobium- 1 %Zirconium (Nb-1 Zr) and other refractory metals/alloys including Tantalum, Molybdenum, Tungsten, and Rhenium alloys. This welding technique is going to be used for the nuclear reactor within JIMO.

  15. Heat resistance insulation for NPP pipelines and components

    International Nuclear Information System (INIS)

    To insulate hot surfaces of NPP process equipment and pipes it is suggested to use heat resistant insulation of foam aminoimides (FAI). Relative toxicity of aceton and acetaldehyd evolved from FAI in the process of thermal and thermal-oxidative break-down was determined. FAI can be used at 200 deg C

  16. 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.

  17. Determination of preheating temperature for welding of heat resisting steels

    International Nuclear Information System (INIS)

    An effect of thermal ageing and blue brittleness on the properties of a weld metal and a heat affected zone has been investigated on 12Kh1MF, 15Kh2MFA and other steels. It is shown that during welding of heat-resistant steels the preheating temperature should not exceed 130-180 deg C

  18. Study on tritium · hydrogen permeation in the HTTR hydrogen production system. 1. Hydrogen permeability of Hastelloy XR (contract research)

    International Nuclear Information System (INIS)

    The High-Temperature Engineering Test Reactor (HTTR) is under construction at Japan Atomic Energy Research Institute (JAERI), and the first criticality is scheduled in the second half of 1998. After the reactor performance and safety demonstration test will be performed for several years, a hydrogen production system by steam reforming of natural gas will be coupled with the HTTR. Prior to coupling of the steam reforming system with the HTTR, an out-of-pile test and essential tests are planned to confirm the safety, controllability and performance of this system under simulated operational conditions. In order to obtain detailed data for a safety review and development of analytical codes, a hydrogen permeation test is carried out with a small-scale apparatus as one of the essential tests. The objective of this study is to evaluate the effectiveness of counter diffusion of hydrogen isotope and oxygen or coating film on the tube surface to reduce the amount of permeated hydrogen. The hydrogen and deuterium permeability of Hastelloy XR and other high-temperature alloys, which will be applied as the tube of an intermediate heat exchanger (IHX) and of a steam reformer (SR), can be obtained from the present test. This paper describes an outline of the hydrogen permeation test apparatus and the hydrogen permeability of Hastelloy XR under the high-temperature conditions ranging from 600degC to 850degC. (author)

  19. 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

  20. 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.??????????? ???????? ?????????? ?????????????? ???????? ?????????? ????????? ?????? ???????????? ??????????? ?? ??????????? ?????????? ??????????. ????????? ???????????? ??????? ???????? ? ????????????, ????????? ????????????? ??????????? ????????????? ? ??????? ???????? ?????????? ???????????? ??? ???? ??????????. ???????? ??????????? ????????, ?????????????? ??????? ? ???? ????, ??? ? ???????? ????????.

  1. Heat resistant driving coil and control rod drive mechanism

    International Nuclear Information System (INIS)

    Ceramic materials are used for each part of driving coils and used as the driving coils for a driving shaft. That is, a cylindrical bobbin having outwardly protruding flanges on the entire circumference at the upper and the lower portions is made of stainless steels. Ceramics sheets are appended as necessary to the outer circumferential surface of the bobbin. Then, ceramic electric wires are wound around the outer circumference of the bobbin by a required number of turns to constitute coils. The electric wire is prepared by coating the conductor of nickel-plated copper with ceramic coating material, disposing an insulation material to the outer circumference thereof the further coating the outside with ceramic coating material. This can improve the heat resistance and, since the control rod drives using such heat resistant driving coils can operate at a high temperature. It requires no cooling device and can simplify the reactor and its peripheral structures. (T.M.)

  2. 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.)

  3. 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.

  4. 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

  5. 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.

  6. Study on the creep constitutive equation of Hastelloy X, (1)

    International Nuclear Information System (INIS)

    A creep constitutive equation of Hastelloy X was obtained from available experimental data. A sensitivity analysis of this creep constitutive equation was carried out. As the result, the following were revealed: (i) Variations in creep behavior with creep constitutive equation are not small. (ii) In a simpler stress change pattern, variations in creep behavior are similar to those in the corresponding fundamental creep characteristics (creep strain curve, stress relaxation curve, etc.). (iii) Cumulative creep damage estimated in accordance with ASME Boiler and Pressure Vessel Code Case N-47 from a stress history predicted by ''the standard creep constitutive equation'' which predicts the average behavior of creep strain curve data is not thought to be on the safe side on account of uncertainties in creep damage caused by variations in creep strain curve. (author)

  7. 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)

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

    OpenAIRE

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

    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...

  9. 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.

  10. Studying microstructure of heat resistant steel deoxidized by barium ferrosilicon

    Directory of Open Access Journals (Sweden)

    A. Z. Issagulov

    2016-07-01

    Full Text Available The paper examined the nature and distribution of non-metallic inclusions in the heat-resistant steel 12H1MF (0,12 % С, 1 % Сr, 0,5 - 0,6 Mo, 0,5 % V, ferrosilicobarim. As a reference, used by steel, deoxidized silicon. Melting was carried out in a laboratory, research-metallic inclusions, their shape and distribution, pollution index were studied according to conventional methods. Studies have shown that ferrosilicobarim deoxidation in an amount of 0,1 - 0,2 %, reduce the overall pollution index of non-metallic inclusions and change the nature of their distribution.

  11. 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

  12. 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)

  13. 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)

  14. 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)

  15. Use of Methods of Metallurgy Sprayed and Fast Quenching Powders for Manufacturing Environments Fuel Tubes from Dispersion-Strengthened Oxides (DSO) Heat Resisting Ferritic-Martensitic Steels (P. 1)

    International Nuclear Information System (INIS)

    The technological circuit and optimum modes hardness alloying ferritic-martensitic nanodispersion yttrium oxide is considered. Results of research of structure and physicomechanical properties of the pre-production models made by a method compacting of powders of heat resisting steel EP-450 DSO are resulted. It is shown, that nanostructured steel keeps high enough residual lengthening after cold deformation on 60%

  16. Investigation into chemical composition of heat resisting coatings Ni-Co-Cr-Al-Y obtained by direct electron beam evaporation in vacuum

    International Nuclear Information System (INIS)

    The AES has been employed to reveal inhomogeneities in the depth elemental concentration on coverages Ni-Co-Cr-Al-Y obtained by the method of direct electron-beam evaporation in vacuum on the heat resistant alloy substrate. The observed inhomogeneities, termed as equidistant growth surfaces, are characterized by jumps of concentrations of Al, Cr, C and O and by a shift of Auger-peaks towards the low-energy spectrum region. The formation of equidistant growth surfaces is related both to a change of the deposition process parameters and selectivity of the mass transport of the components of the starting alloy

  17. 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

  18. 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.

  19. 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.)

  20. 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)

  1. 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...

  2. Change of heat resistance on spore forming bacteria after irradiation

    International Nuclear Information System (INIS)

    The effect of heat resistance of endospores after gamma-irradiation were investigated for application to decontaminate microorganisms in spices or other dried food materials. D10 values of endospores dried on glass fiber filter with additives of 2% peptone + 1% glycerin were obtained to be 1.8 kGy for Bacillus pumilus, 1.1 kGy for B. cereus, 2.2 kGy for Clostridium botulinum Type A and 2.4 kGy for Cl. botulinum Type E, respectively. Non-irradiated endospores of B. pumilus and B. cereus were inactivated with 40 min of heat treatment at 100degC in water. When endospores were irradiated with 5 kGy, these bacteria were inactivated below 20 min of heating at 100degC in water. In the case of Cl. botulinum Type A and Type E, non-irradiated endospores were inactivated with 30 min of heat treatment at 100degC in water, and irradiated endospores at 5 kGy were inactivated below 15 min of heating. However, all of these bacteria could not inactivate endospores even after heating more than 2 hours at 100degC in dry condition or 80degC in water, and decreased a little of necessary times for inactivation of heat treatment after irradiation at 5 kGy. (author)

  3. 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

  4. 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)

  5. 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.

  6. 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.

  7. 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...

  8. 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

  9. FY 1998 annual report on the study on solidification process of hot, heat-resistant metal melts; 1998 nendo tainetsu kinzoku koon yueki no gyoko katei no kenkyu chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Described herein are results of the studies on basic aspects of solidification process of hot, heat-resistant metal melts under a microgravity atmosphere, its applicability to industrial purposes, production of new metallic structures by precision casting and supercooling solidification of the heat-resistant, metal alloy parts, and evaluation techniques therefor. In the supercooling solidification of Al, its purity greatly determines the crystal morphology. The single crystal can be produced under a microgravity when it is 99.9% pure. The supercooling solidification under a microgravity can give an Al-Pb alloy structure of uniform dendrite structure both on the surface and inside, free of gravity-caused segregation of Pb. The welding problems caused by Al{sub 2}O{sub 3} present in the Al are solved. The study also clarifies the effects of the microgravity atmosphere in the spot welding by a pulsed YAG laser on, e.g., melting characteristics, welding phenomena and formation of welding defects. The basic knowledge obtained is expected to contribute to, e.g., precision casting and welding of heat-resistant alloys, and creation of new alloys. (NEDO)

  10. On one algorithm of searching optimum alloying complex

    International Nuclear Information System (INIS)

    The algorithm prepared determines the optimum combination of the alloying elements on the basis of the apriori information methods and Monte-Carlo method provides for calculating the expected properties at the given combination of the alloying elements. The tests carried out on the heat-resisting nickel alloys have proved that the calculations almost coincide with the experimental data

  11. The substitution of molybdenum by vanadium in high alloy castings

    International Nuclear Information System (INIS)

    The possibility of substituting molybdenum with vanadium both partially and completely in high alloy castings because of vanadium's availability in Southern Africa and its relatively lower cost, was studied. The high alloy castings used in the investigation include: ACl Types CF-8M and CG-8M, alloys similar to ACl Type CN-7M and the proprietory grade nickel-base alloys Hastelloy B and Hastelloy C. They were investigated, with respect to general corrosion resistance in phosphoric, sulphuric and hydrochloric acid and localised attack in chloride media, using potentiodynamic and immersion tests conforming to ASTM standards. Vanadium emerges as an inadequate substitute except with the cast austenitic stainless steels where it may find limited application as a partial substitute

  12. 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.

  13. Microstructure evolution during service exposure of two cast, heat-resisting stainless steels - HP-Nb modified and 20-32Nb

    International Nuclear Information System (INIS)

    The repair weldability of two types of heat-resistant austenitic stainless steel castings, HP-Nb modified alloys and 20-32Nb alloys, has been evaluated after extended service exposure of these materials at temperatures on the order of 815 deg. C (1500 deg. F). The initial part of this investigation has focused on characterization of the microstructure of these alloys after service exposure times of up to 12 years. Microstructure evolution from the as-cast condition to the service-exposed condition is described. In the as-cast condition, both eutectic NbC and Cr-rich M7C3 carbides were observed in the HP-Nb alloys. In contrast, only eutectic NbC carbides were present in the as-cast 20-32Nb alloys due to a significantly higher atomic ratio of Nb/C as compared to the HP-Nb alloys. In the service-exposed condition, an Ni-Nb silicide and Cr-rich M23C6 were identified in both alloys. The HP-Nb alloys exhibited a much higher total volume fraction of microconstituents than the 20-32Nb alloys and the M23C6 phase was more prevalent than Ni-Nb silicide. In contrast, the Ni-Nb silicide was dominant in the service-exposed 20-32Nb alloys. This difference resulted in a significant increase in the repair welding liquation cracking susceptibility of the 20-32Nb service-exposed alloy

  14. 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

  15. Effects of high temperature environment on creep properties of hastelloy X

    International Nuclear Information System (INIS)

    In order to clarify the creep properties of Hastelloy X, that is one of the materials discussed for use in VHTR, in helium at extremely high temperature, creep and rupture tests in helium and in air were carried out on Hastelloy X at temperatures of 9000C and 10000C. No remarkable differences between primary and secondary creep rates in helium and those in air were observed. On the other hand, the initiation of tertiary creep was slower and the period of tertiary creep shorter in helium than in air. Moreover, rupture ductilities decrease in helium as compared with those in air. Those differences are considered to be dependent of less internal oxidation and sharper crack tips in helium than in air. (author)

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Min, E-mail: liumin@sinap.ac.cn; Zheng, Junyi; Lu, Yanling, E-mail: luyanling@sinap.ac.cn; Li, Zhijun; Zou, Yang; Yu, Xiaohan; Zhou, Xingtai, E-mail: zhouxingtai@sinap.ac.cn

    2013-09-15

    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.

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

    Science.gov (United States)

    Liu, Min; Zheng, Junyi; Lu, Yanling; Li, Zhijun; Zou, Yang; Yu, Xiaohan; Zhou, Xingtai

    2013-09-01

    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.

  3. 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).

  4. The one-parameter-model - a constitutive equation applied to a heat resistant alloy

    International Nuclear Information System (INIS)

    In the present work a constitutive model earlier developed and used to predict experimental results of hot tests and fatigue tests from creep experiments of metallic materials were modified to comply with the properties of a high temperature resistant material. The improved model accounts for the properties of a material developing a density and a structure of dislocation lines which are capable of interactions with particles (carbides) from a second phase. The time and temperature dependent evolution of the carbide structure has been described by an equation which explains the formation of seeds as well as their growths (Ostwald ripening). The extended model was applied to Incoloy 800H which is known to develop a carbide structure. Therefore hot tensile and fatigue tests, creep and relaxation experiments using the heats ADU and BAK (KFA specifications) at temperature between 800deg C and 900deg C were performed including both solution treated specimens and specimens heat treated for 10, 100 and 1000 hours. As compared with the results from tensile tests where the carbide structures play a subordinated role, alternately, these structures have a decisive influence on the creep properties of specimens during the primary creep phase, i.e. low stresses and high temperatures. (orig.)

  5. Broadening of temperature range when testing heat-resistant alloys for high-temperature chloride corrosion

    International Nuclear Information System (INIS)

    Results of corrosion resistance of materials with nickel, iron and chromium base (EhK-9VD, Kh18N10T and VKh-2K) in sodium chloride, equimolar mixture of sodium and potassium chlorides and internary eutectics (48.7 % of MgCl2 + 38.2 % of KCl+13.1 % of NaCl) at 400-900 deg C temperature and 20 hour exposure are presented. it is shown that application of ternary mixture instead of sodium chloride and binary chloride mixture indicated allows one to reduce the temperature of testing for chloride corrosion resistance down to 410 deg C, and thus to broaden the testing temperature range by 250-400 deg C

  6. Heat-resistant fungi of importance to the food and beverage industry.

    Science.gov (United States)

    Tournas, V

    1994-01-01

    Spoilage of pasteurized and canned fruit and fruit products caused by heat-resistant molds have been reported repeatedly in recent years. Species most commonly implicated in fruit and fruit product disintegration are Byssochlamys fulva, Byssochlamys nivea, Neosartorya fischeri, Talaromyces flavus, and Eupenicillium brefeldianum. These organisms are saprophytic rather than parasitic and usually contaminate fruits on or near the ground. They can survive heat treatments used for fruit processing and can grow and spoil the products during storage at room temperature, which results in great economic losses. Mold heat resistance is attributed to the formation of sexual spores, ascospores. Ascospores have a wide range of heat resistance, depending on species, strain, age of organism, heating medium, pH, presence of sugars, fats, and acids in heating medium, growth conditions, etc. The mechanism(s) of thermoresistance are not clear; probably some very stable compound(s) critical to germination and outgrowth are present in the heat-resistant ascospores. Besides spoilage, the heat-resistant molds produce a number of toxic secondary metabolites, such as byssotoxin A; byssochlamic acid; the carcinogen, patulin, the tremorgenic substances, fumitremorgin A and C, and verruculogen; fischerin, which caused fatal peritonitis in mice; and eupenifeldin, a compound possessing cytotoxicity as well as in vivo antitumor activity. Growth of heat-resistant fungi can be controlled by lowering the water activity, adding sulfur dioxide, sorbate, or benzoate; washing of fruits in hypochlorite solution before heat treatment reduces the number of ascospores and makes the heat destruction more successful. More research is needed to elucidate the mechanism(s) of thermoresistance and develop new methods for the complete inactivation of resistant ascospores. PMID:7857517

  7. 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)

  8. 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.)

  9. 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.

  10. Creep behaviour of heat-resistant power plant steels under rectangular cyclic stress

    International Nuclear Information System (INIS)

    The modified life component rule is suitable for describing, to a great extent, the rectangular cyclic creep behaviour of a series of typical heat-resistant steels. In order to predict fracture time or expansion boundary time, the data of a stress cycle are necessary in addition to the normal creep values of a steel. (orig.)

  11. 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.

  12. Transparent Heat-Resistant PMMA Copolymers for Packing Light-Emitting Diode Materials

    OpenAIRE

    Shu-Ling Yeh; Chao-Yuan Zhu; Shiao-Wei Kuo

    2015-01-01

    Transparent and heat-resistant poly(methyl methacrylate) copolymers were synthesized by bulk polymerizing methyl methacrylate (MMA), isobornyl methacrylate (IBMA), and methacrylamide (MAA) monomers. Copolymerization was performed using a chain transfer agent to investigate the molecular weight changes of these copolymers, which exhibited advantages including a low molecular weight distribution, excellent optical properties, high transparency, high glass transition temperature, low moisture a...

  13. Fatigue crack growth characteristic of hastelloy X in air at elevated temperature

    International Nuclear Information System (INIS)

    Fatigue crack growth tests on Hastelloy X were conducted in air at 7500C and 9000C. Varied contribution of creep was given by choosing the stress ratio levels between 0 to 1. Three fracture modes were observed, i.e. transgranular fatigue mode, intergranular creep mode and transition from transgranular to intergranular mode, according to the degree of contribution of creep effect. In handling of the crack growth rate data with fracture mechanical parameter, da/dN-?K relation, da/dN-?J relation and da/dt-j relation were found to be appropreate for the three modes respectively. (author)

  14. FY 1997 report on the study on solidification process of high-temperature melt of heat resistant metals; 1997 nendo chosa hokokusho (tainetsu kinzoku koon yueki no gyoko katei no kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Study was made on a solidification process of metal melt under micro-gravity condition in an underground non-gravity experiment center, considering that improvement of the heat resistance of turbine blades for jet engines and power generation gas turbines contributes to prevention of global warming through improvement of thermal engine efficiencies and consumption reduction of precious fossil fuel. Study was made on a simulation program and precise measurement of thermal properties for precision casting of heat-resistant alloy members. Study was also made on Al and Zn alloys and their welding for production and evaluation technologies of new metal textures by supercooling solidification. Some issues for strongly desired improvement of a simulation program for precision casting were clarified. In addition, since thermal property data of practical heat-resistant polyalloy members are poor, data and measurement method for precision casting were clarified. It was also suggested that basic elucidation of the solidification process under micro- gravity condition is possible. 34 refs., 41 figs., 5 tabs.

  15. Tendency to amorphous state formation in V-Zr-Mo system alloys

    International Nuclear Information System (INIS)

    Investigation into conditions of V-Zr-Mo system alloys production and determination of amorphization intervals under gaseous deposition is conducted. 20 ?m thick foils of ternary alloys in amorphous state, stable under heating up to 900 deg C, are produced. It is shown, that vanadium introduction allows one to increase the alloy ductility with the material heat resistance being preserved

  16. 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

  17. 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)

  18. Heat-resistance of Hamigera avellanea and Thermoascus crustaceus isolated from pasteurized acid products.

    Science.gov (United States)

    Scaramuzza, Nicoletta; Berni, Elettra

    2014-01-01

    Products containing sugar or fruit derivatives are usually subjected to a pasteurization process that can anyway be ineffective to kill ascospores from heat-resistant molds. Although the most occurring and economically relevant heat-resistant species belong to Byssochlamys, Neosartorya, Talaromyces, and Eupenicillium genera, an increasing number of uncommon heat-resistant isolates have been recently detected as spoiling microorganisms in such products. Since Hamigera spp. and Thermoascus spp. were those more frequently isolated at SSICA, heat resistance of Hamigera avellanea and Thermoascus crustaceus strains from pasteurized acid products was studied in apple juice, in blueberry and grape juice and in a buffered glucose solution. Data obtained from thermal death curves and statistical elaboration of raw data showed that D values of H. avellanea may vary between 11.11 and 66.67 min at 87°C, between 4.67 and 13.51 at 90°C, and between 0.43 and 1.52 min at 95°C. Similarly, D values of T. crustaceus may vary between 18.52 and 90.91 min at 90°C, between 2.79 and 19.23 at 93°C, and between 1.11 and 2.53 min at 95°C. For both strains studied, the z-values calculated from the decimal reduction time curves did not prove to be significantly influenced by the heating medium, that being 4.35°C, 5.39°C or 5.27°C for H. avellanea and 4.42°C, 3.69°C or 3.37°C for T. crustaceus, respectively in apple juice, in blueberry and grape juice or in the buffered glucose solution. Considering the pasteurization treatments industrially applied to fruit-based foods, the variation of thermal parameters does not seem to be a possible way to avoid product spoilage by these two species and only good practices applied to reduce the original load of heat-resistant fungi can help producers to prevent losses in contaminated finished products, as usually happens for other heat resistant molds. PMID:24239977

  19. Changes of the permeability of hydrogen of heat resisting metallic materials caused by thin oxide barriers on the surface

    International Nuclear Information System (INIS)

    The permeability of hydrogen and tritium through oxide surface layers of Incoloy 800, Incoloy 800H, Incoloy 802, Incoloy 807, IN 586, Inconel 617, Hastelloy X, HK 40, Manaurite 36X, IN 519, IN 638 and IN 643 was studied dependent on temperature (600-10000C) and hydrogen pressure (1-20 bar). (TWO)

  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. Influence of Dispersed Heat-Resistant Additives on Ignition and Combustion of Heterogeneous Systems

    Directory of Open Access Journals (Sweden)

    Arkhipov V.A.

    2015-01-01

    Full Text Available The results of experimental studies of the effect of dispersion of heat-resistant additives powders on ignition and combustion of heterogeneous condensed systems. The method of measuring the time delay ignition conductive and radiant heating, and combustion rate at atmospheric pressure. The effect of additives powders of boron, silicon and titanium dioxide on the ignition and combustion of heterogeneous condensed systems.

  2. 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 ...

  3. Fermi level of carriers in the volume filling defects structure based on heat-resistant metals

    OpenAIRE

    Marenkov, V.I.

    2011-01-01

    The volume filling defects structure based on metals are widely used in modern nan- otechnology, especially when creating high temperature sensors and structural elements based on metal foams [1]. The development of contactless and nondestructive methods for diagnosis and test control parameters of multiply connected matrix base material is a very important and interesting aspect of the application [2]. In a heat-resistant metal with the volume filling defects (VFD) (micro-...

  4. 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

  5. Agni's fungi: heat-resistant spores from the Western Ghats, southern India.

    Science.gov (United States)

    Suryanarayanan, T S; Govindarajulu, M B; Thirumalai, E; Reddy, M Sudhakara; Money, Nicholas P

    2011-09-01

    This study concerns the thermotolerance of spores of mesophilic fungi isolated from a tropical semi-arid habitat subject to dry season fire in the Western Ghats, southern India. Among 25 species of Ascomycota isolated from leaf litter, nine were able to grow after incubation in a drying oven for 2h at 100°C; the spores of two of these species survived 2h incubation at 110°C, and one survived exposure to 115°C for 2h. The range of thermotolerance among mesophilic fungi isolated from the leaf litter was surprising: filamentous fungi from other habitats, including species that colonize scorched vegetation after fires and thermophilic forms occurring in self-heating plant composts, cannot survive even brief exposure to such high temperatures. It is possible that the exceptional heat resistance of the Indian fungi is related to adaptations to surviving fires. Genetic analysis of the physiological mechanisms of heat resistance in these fungi offers prospects for future biotechnological innovations. The discovery of extreme thermotolerance among common saprotrophs shows that this physiological trait may be more widespread than recognized previously, adding to concern about the evolution of opportunistic pathogens on a warmer planet. The fungi in this study are among the most heat-resistant eukaryotes on record and are referred to here as 'Agni's Fungi', after the Hindu God of Fire. PMID:21872180

  6. High-strength Ag-alloyed structural underdensity Al-Cu-Li-Mg alloy

    International Nuclear Information System (INIS)

    Mechanical properties under static and dynamic loads, fatigue characteristics, viscosity cleavage, heat resistance, corrosion resistance, physical and thermophysical properties of the pressed underdensity alloy V-1469 have been studied. The alloy corresponds as aluminium deformed high-strength thermally strengthened alloy on the basis of the Al-Cu-Li-Mg system extra alloyed by Ag, Zr, Sc. Comparison of properties of V-1469T1, V95ochT2 and V96ts3-pchT12 alloys pressed flat is conducted

  7. 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

  8. 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

  9. On the metallurgical and environmental factors affecting creep behaviour of hastelloy-x

    International Nuclear Information System (INIS)

    Deformation and rupture processes of Hastelloy-X and its modified version in different environment including air, the simulated HTR helium and high vacuum were compared. All the environments showed the effects different from each other. The high vacuum condition caused best reproducible creep and rupture behaviour, and essentially no size effect was involved. While the others caused considerable surface-to-volume ratio effect, and the simulated HTR helium environment showed characteristic effects. The latters were interpleted as the results of the depletion of chromium and molybdenum due respectively to the selective oxidation of the active elements and carburization to enhance the formation of M6C to eventually cause recrystallization of the austenite matrix. (author)

  10. Helium blistering of ceramic coatings on Hastelloy X and Nb--1% Zr

    International Nuclear Information System (INIS)

    The surface damage of insulating ceramic coatings on Hastelloy X and Nb--1 percent Zr held at room temperature and at 3000C has been studied for both 100- and 250-keV helium ion irradiation for a dose range from 3.7 x 1018 to 1 x 1019 ions cm-2. Blisters were observed after room temperature irradiation with both 100- and 250-keV helium ions. However, for irradiation at 3000C no blisters could be observed. The sharp rise in the helium permeation with temperature, observed by others for some glasses and ceramics, is thought to be responsible for this behavior. These results suggest that for the energy range studied, helium blistering has a negligible surface erosion effect on such coatings if they are operated at temperatures above 3000C

  11. Operating experience with the heat-resistant material 15 NiCuMoNb 5 in conventional power plants

    Energy Technology Data Exchange (ETDEWEB)

    Adamsky, F.J.; Teichmann, H.; Tolksdorf, E.

    1998-07-01

    The forerunners of the material 15 NiCuMoNb 5 (WB 36), known as CuNi steels for boiler drums, allowed operating pressures to exceed 100 bar for the first time in the 30s, thereby creating the basis for power station to achieve high performance and efficiency levels. Even present day steel developments for the thick walled components used in nuclear technology have almost reached the level of this steel with regard to the high temperature limit of elasticity as a design value up to temperatures of 400 C, but have not exceeded it. In the mid-60s, extensive investigations were carried out into these materials following a few spectacular cases of serious damage, basically manifesting themselves in two ways: as cracks in the area of the downpipe bores and brittle fractures revealed by pressure testing. The cracks were recognized as stress/strain-induced corrosion and this was counteracted internally by improving the quality of the water, particularly with regard to its oxygen content. The inadequate toughness characteristics, responsible for the fractures occurring during the pressure test, were improved by specific alloying measures and in particular by reducing the sulphur content. Particular attention was paid to welding work. Reporting on operating experience means reporting the results of investigations into damage to components made from heat-resistant materials and providing a critical evaluation. A few examples are summarized below for this purpose. Some are current examples and others go back a few years, but are still the subject of discussion in the sector because of the fundamental knowledge to be gained from them.

  12. 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.

  13. Materials for Advanced Turbine Engines (MATE): Project 3: Design, fabrication and evaluation of an oxide dispersion strengthened sheet alloy combustor liner, volume 1

    Science.gov (United States)

    Henricks, R. J.; Sheffler, K. D.

    1984-01-01

    The suitability of wrought oxide dispersion strengthened (ODS) superalloy sheet for gas turbine engine combustor applications was evaluated. Incoloy MA 956 (FeCrAl base) and Haynes Developmental Alloy (HDA) 8077 (NiCrAl base) were evaluated. Preliminary tests showed both alloys to be potentially viable combustor materials, with neither alloy exhibiting a significant advantage over the other. Both alloys demonstrated a +167C (300 F) advantage of creep and oxidation resistance with no improvement in thermal fatigue capability compared to a current generation combustor alloy (Hastelloy X). MA956 alloy was selected for further demonstration because it exhibited better manufacturing reproducibility than HDA8077. Additional property tests were conducted on MA956. To accommodate the limited thermal fatigue capability of ODS alloys, two segmented, mechanically attached, low strain ODS combustor design concepts having predicted fatigue lives or = 10,000 engine cycles were identified. One of these was a relatively conventional louvered geometry, while the other involved a transpiration cooled configuration. A series of 10,000 cycle combustor rig tests on subscale MA956 and Hastelloy X combustor components showed no cracking, thereby confirming the beneficial effect of the segmented design on thermal fatigue capability. These tests also confirmed the superior oxidation and thermal distortion resistance of the ODS alloy. A hybrid PW2037 inner burner liner containing MA956 and Hastelloy X components was designed and constructed.

  14. Welding consumables for mechanized welding of heat-resistant steel pipelines

    International Nuclear Information System (INIS)

    A study was made on properties of welding joints of 15Kh1M1F steel produced under the flux AN-43 in combination with Sv-08KhGSMFA and Sv-08KhMFA wires, as well as under the flux ANK-47 in combination with Sv-08KhMFA wire. It was established that AN-43 flux with Sv-08KhGSMFA wire provided for higher level of mechanical properties and long-term strength and could be recommended for automatic welding of heat resisting steels of 15Kh1M1F type

  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. 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.)

  18. Transparent Heat-Resistant PMMA Copolymers for Packing Light-Emitting Diode Materials

    Directory of Open Access Journals (Sweden)

    Shu-Ling Yeh

    2015-07-01

    Full Text Available Transparent and heat-resistant poly(methyl methacrylate copolymers were synthesized by bulk polymerizing methyl methacrylate (MMA, isobornyl methacrylate (IBMA, and methacrylamide (MAA monomers. Copolymerization was performed using a chain transfer agent to investigate the molecular weight changes of these copolymers, which exhibited advantages including a low molecular weight distribution, excellent optical properties, high transparency, high glass transition temperature, low moisture absorption, and pellets that can be readily mass produced by using extrusion or jet injection for packing light-emitting diode materials.

  19. The effects of radiation on aluminium alloys in the core of energy nuclear reactors

    International Nuclear Information System (INIS)

    One of the attractive directions in the worldwide practice of nuclear installations is the replacement of expensive zirconium alloy with more cheap materials, particularly aluminium allo. For Heat Supply Nuclear Plants (HSNP) with approximately 473 K core temperatures, the use of heat-resistant aluminium alloys seems to be reasonable. The present work is concerned with the studies on radiation effects on aluminium alloy, and interaction between the alloy and coolant in the reactor core. (author). 2 refs., 3 figs., 1 tab

  20. 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)

  1. 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)

  2. Effect of heating rate on highly heat-resistant spore-forming microorganisms.

    Science.gov (United States)

    Gómez-Jódar, Isabel; Ros-Chumillas, María; Palop, Alfredo

    2016-03-01

    Highly heat-resistant spore-forming Bacillus cause nonsterility problems in canned food and reduce the shelf life of many processed foods. The aim of this research was to evaluate the thermal inactivation of Bacillus sporothermodurans IIC65, Bacillus subtilis IC9, and Geobacillus stearothermophilus T26 under isothermal and nonisothermal conditions. The data obtained showed that B. sporothermodurans and B. subtilis were more heat resistant than G. stearothermophilus. The survival curves of B. sporothermodurans and B. subtilis showed shoulders, while the survival curves of G. stearothermophilus showed tails. Under nonisothermal treatment, at heating rates of 1 and 20 ℃/min, time needed to completely inactivate G. stearothermophilus was shorter than that required for B. sporothermodurans and B. subtilis. In complex heat treatments (heating-holding-cooling), the survival curves of B. sporothermodurans and B. subtilis showed the same activation shoulders than those obtained under isothermal treatments and the activation shoulders were again absent in the case of G. stearothermophilus. Predictions fitted quite well the data obtained for B. sporothermodurans. In contrast, the data for B. subtilis showed half a log cycle more survival than expected and in the case of G. stearothermophilus, the survival curve obtained showed much higher inactivation than expected. PMID:25852134

  3. 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.)

  4. Effect that radiation exerts to insulation breakdown of heat resistant polymer materials

    International Nuclear Information System (INIS)

    Artificial satellites are always exposed to cosmic rays which contain the radiations which do not reach the ground, therefore, the radiation resistance of the polymer insulators for cables and others used in such environment becomes a problem. Also the polymer insulator materials used for nuclear facilities require excellent radiation resistance. It is important to examine the effect that radiation exerts to electric insulation characteristics from the viewpoint of material development. In this paper, the insulation breakdown characteristics of heat resistant polymer films and the mini-cables made for trial of heat resistant polymer materials in the case without irradiation and in the case of gamma ray irradiation, and the results of the structural analysis are reported. The specimens tested, the experimental method and the results are described. The insulation breakdown strength of PFA and FEP films lowered from 0.15-0.2 MGy, but that of PEEK film did not change up to 5 MGy. It was found that fluorine group resins were apt to deteriorate by oxidation as dose increased. (K.I.)

  5. Effect of pH on Thermoanaerobacterium thermosaccharolyticum DSM 571 growth, spore heat resistance and recovery.

    Science.gov (United States)

    Mtimet, Narjes; Guégan, Stéphanie; Durand, Lucile; Mathot, Anne-Gabrielle; Venaille, Laurent; Leguérinel, Ivan; Coroller, Louis; Couvert, Olivier

    2016-05-01

    Thermophilic spore-forming bacteria are potential contaminants in several industrial sectors involving high temperatures (40-65 °C) in the manufacturing process. Among those thermophilic spore-forming bacteria, Thermoanaerobacterium thermosaccharolyticum, called "the swelling canned food spoiler", has generated interest over the last decade in the food sector. The aim of this study was to investigate and to model pH effect on growth, heat resistance and recovery abilities after a heat-treatment of T. thermosaccharolyticum DSM 571. Growth and sporulation were conducted on reinforced clostridium media and liver broth respectively. The highest spore heat resistances and the greatest recovery ability after a heat-treatment were obtained at pH condition allowing maximal growth rate. Growth and sporulation boundaries were estimated, then models using growth limits as main parameters were extended to describe and quantify the effect of pH on recovery of injured spores after a heat-treatment. So, cardinal values were used as a single set of parameters to describe growth, sporulation and recovery abilities. Besides, this work suggests that T. thermosaccharolyticum preserve its ability for germination and outgrowth after a heat-treatment at a low pH where other high resistant spore-forming bacteria like Geobacillus stearothermophilus are unable to grow. PMID:26742617

  6. Heat resistance of ascospores of Byssochlamys nivea in milk and cream.

    Science.gov (United States)

    Engel, G; Teuber, M

    1991-02-01

    Byssochlamys nivea strains of rather varying origin used for heat inactivation experiments were cultured for 28 days at 30 degrees C on malt extract agar, since under these conditions the highest degree of heat resistance of the ascospores was observed. Inactivation was performed in steel capillary tubes to obtain reproducible results under experimental conditions comparable to those prevailing in practice. An inactivation temperature of 92 degrees C proved to be most practical. Decimal reduction times for the individual strains at this temperature in Ringer's solution varied between 1.3 and 2.4 s. In the temperature range studied, inactivation of ascospores in UHT milk (1.5% w/w fat content) and cream (10% w/w fat content) has not been found to differ significantly from that in Ringer's solution. Homogenization of milk as applied in practice did not affect heat inactivation of ascospores. Assuming the most unfavorable conditions (50 ascospores/l and using the most heat-resistant strain) the following relations between the level of infected 500 g packages were calculated: 1 of 10(6) packs infected; 24 s at 92 degrees C; 1 of 10(3) packs infected; 16.5 s at 92 degrees C; 1 of 10(2) packs infected, 14 s at 92 degrees C. PMID:2049287

  7. 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.

  8. 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)

  9. Process of brazing using low temperature braze alloy of gold-indium tin

    International Nuclear Information System (INIS)

    A heat resistant brazing alloy of a major amount of gold, a lesser amount of indium and a minor amount of tin. The alloy is particularly suited for use in bonding electrical components to chip carrying substrates which are to be reworked

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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)

  15. 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.

  16. 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

    2016-01-01

    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.

  17. 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)

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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)

  3. 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 of extrolite profiles were applied. Phylogenetic analyses revealed that the genus Byssochlamys...... immunosuppressant mycophenolic acid. Byssochlamys lagunculariae produces byssochlamic acid and mycophenolic acid and thus chemically 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...

  4. Water soluble and heat resistant polymers by free radical polymerization of lactic acid-based monomers

    Science.gov (United States)

    Tanaka, Hitoshi; Kibayashi, Tatsuya; Niwa, Miki

    2013-08-01

    Tactic heat resistant polymer was prepared by free radical polymerization of lactic acid-based monomers, i.e. chiral 2-isopropyl-5-methylene-1,3-dioxolan-4-ones (1). The polymerization of 1 proceeded smoothly without ring-opening to give a polymer with high isotacticity (mm) of 29.7~100% and glass transition temperature (Tg) of 172~213°C. 1 also showed high reactivity in the copolymerization with styrene and methyl methacrylate, and the incorporation of 1 unit in the copolymer structure increased Tg of each polymer. In addition, hydrolysis of poly(1) produced a new type of water soluble poly(lactic acid), i.e. poly(?-hydroxy acrylate), and poly(?-hydroxy acrylate-co-divinyl benzene) hydrogel absorbed water as high as 1000 times of the original polymer weight.

  5. Fire- and heat-resistant laminating resins based on maleimido-substituted aromatic cyclotriphosphazenes

    Science.gov (United States)

    Kumar, D.; Fohlen, G. M.; Parker, J. A.

    1983-01-01

    A novel class of flame- and heat-resistant polymers has been synthesized by the thermal polymerization of maleimido-substituted aromatic cyclotriphosphazenes. The polymer obtained from tris-(aminophenoxy)tris(maleimidophenoxy)cyclotriphosphazene has good thermal stability and is noteworthy for its high char yield, viz., 82 percent at 800 C in nitrogen and 81 percent at 700 C in air. Graphite-fabric laminates prepared with this polymer did not burn in pure oxygen, even at 300 C, and were tested for mechanical properties. Hexakis(4-maleimidophenoxy)cyclotriphosphazene and some fluorine-containing monomers have also been synthesized. The structures of these cyclic phosphazene precursors and polymers were characterized by FT IR spectrophotometry, H-1 NMR, F-19 NMR, and P-31 solid-state magic angle spinning NMR spectroscopy, and mass spectrometry. The curing behavior of the polymer precursors and the thermal stabilities of the polymers were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA).

  6. Thermal conductivity, electrical resistivity, and thermopower of aerospace alloys from 4 to 300 K.

    Science.gov (United States)

    Hust, J. G.; Weitzel, D. H.; Powell, R. L.

    1971-01-01

    Measurement of thermal conductivity, electrical resistivity, and thermopower for several aerospace alloys: titanium alloy A110-AT, aluminum alloy 7039, Inconel 718, and Hastelloy X. Tables and graphs of the measured properties and Lorenz ratio are presented over the range from 4 to 300 K. Comparisons to other measurements and theoretical analysis of the data are included. The uncertainties of the property data are estimated as 0.7 to 2.5% for thermal conductivity, 0.25% in electrical resistivity, and about 0.1 microvolt/K in thermopower.

  7. 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

  8. Data on post irradiation experiments of heat resistant ceramic composite materials. PIE for 97M-13A

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Shin-ichi; Ishihara, Masahiro; Souzawa, Shizuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Sekino, Hajime [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The research on the radiation damage mechanism of heat resistant ceramic composite materials is one of the research subjects of the innovative basic research in the field of high temperature engineering, using the High Temperature engineering Test Reactor (HTTR). Three series of irradiation tests on the heat resistant ceramic composite materials, first to third irradiation test program, were carried out using the Japan Material Testing Reactor (JMTR). This is a summary report on the first irradiation test program; irradiation induced dimensional change, thermal expansion coefficient, X-ray diffraction and {gamma}-ray spectrum are reported. (author)

  9. Corundum Molds for Investment Casting from Refractory Alloys and Metals

    OpenAIRE

    Murkina, A. S.; M. S. Varfolomeev; D.V. Sidorov; Storozhenko, P. A.; Shcherbakova, G. I.

    2010-01-01

    Production procedure, physical-chemical, and performance properties of ALUMOX silica-free binder used for the production of high-heat-resistant corundum shell molds by consumable patterns employed in the production of critical molds from superalloyed reactive metals and alloys are described. ALUMOX usage allows obtaining casts from reactive metals and alloys with surface roughness up to 6 0 ? m), which, in its turn, increases fatigue parameters of the mat...

  10. Effect of mixed heat-resistances on the optimal configuration and performance of a heat-engine cycle

    International Nuclear Information System (INIS)

    The finite-time thermodynamic performance of a generalized Carnot-cycle, under the condition of mixed heat-resistances, is studied. The optimal configuration and the fundamental optimal relation between power and efficiency of the cycle are derived. The results provide some guidance for the design of practical engines

  11. Feasibility study on potential productivity of heat-resisting and advanced semiconductors by using the HTTR

    International Nuclear Information System (INIS)

    Worldwide attention has been paid to GaAs and SiC as a kind of the heat-resisting and advanced semiconductor materials. Doping of specific impurities into semiconductor materials is a key technology for producing semiconductor devices. As one of doping technologies, thermal diffusional doping has been successfully applied to Si. Application of thermal diffusional doping to GaAs needs expensive and complicated processes in order to prevent an occurrence of lattice defects by impurities. On the other hand, it is difficult to apply this technology to SiC, because of small diffusion coefficient of impurities to SiC. Therefore, it is of great importance to develop a substitutional doping technology for these materials for realizing heat-resisting and advanced semiconductor. To dope some impurities into Si crystal by using neutron irradiation is a mature technology and is called NTD. The High Temperature engineering Test Reactor(HTTR) has an unique and superior capability to irradiate large-sized specimen, in the order of 10cm in diameter, at high temperature up to approximately 1000degC. This report presents a result of feasibility study of potential applicability and effectiveness of NTD to GaAs and SiC at the HTTR. First of all, advantages and disadvantages were identified by reviewing the state-of-the-art technology of NTD to Si. Potential applicability of NTD to GaAs and SiC are discussed. Based on this discussion, effectiveness and feasibility of NTD to these materials at the HTTR are examined. As a result, NTD is feasible to SiC but not to GaAs. The HTTR provides the capability to produce SiC semiconductor, in particular, to produce the semiconductor with (1) low irradiation damage, (2) uniform distribution of doped impurities and (3) high productivity, if a large-sized SiC crystal is capable to be commercialized. Practical application of NTD at the HTTR will be discussed in the next study. (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. The technology for automated development of economically doped heat-resistant nickel superalloys

    Directory of Open Access Journals (Sweden)

    Shmotin Yuriy

    2014-01-01

    Full Text Available The paper presents the usage of computational technology, aimed at automated search for optimum compositions of nickel superalloys, being minimally doped by expensive rhenium and having no ruthenium. Resulting doping compositions ensure ultimate long-term high-temperature strength. The technology is based on computer model of alloy and numerical optimization routine. The model computes relation between an alloy composition and its performance characteristics. Multiobjective optimization procedure provides for an automated search for alloy composition to ensure the set of pre-defined properties of a new material. Two new nickel-based single-crystal superalloys are presented, which were created using this technology. SLGS-3 features high-temperature strength (100 hours at 1,000 degrees Centigrade at approximately 345?MPa. Its composition does not contain ruthenium. SLGS-1 alloy provided for 265?MPa and contained neither rhenium nor ruthenium in its composition.

  14. 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

  15. 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)

  16. 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.

  17. 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

  18. 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

  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. Creep deformation characterization of heat resistant steel by stress change test

    International Nuclear Information System (INIS)

    To evaluate the creep deformation mechanism of heat resistant steel, stress change tests were conducted during creep tests for Modified 9Cr-1Mo Steel and 2.25Cr-1Mo Steel. In this study it was confirmed that the dislocation behavior during the creep tests was in viscous manner because of no instantaneous plastic strain observed at stress increments. Transient backward creep behavior was observed after stress reduction for these steels in this work. Mobilities of dislocation were evaluated by observed backward creep behavior after stress reductions. Internal stresses were evaluated by the changes of creep rate in stress increments. And mobile dislocation densities were evaluated with the estimated mobilities of dislocation and the changes of creep rate in stress increments. It was found that the variation of evaluated mobile dislocation densities during creep deformation showed the same tendency as the variation of creep rate. Therefore mobile dislocation density is the dominant factor that influences the creep rate variation in creep deformation of these steels in this work. The mobilities of dislocation showed a good correlation with 1/T and related with solute amount of Mo that is a solution hardening element.

  1. Creep deformation characterization of heat resistant steel by stress change test

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Hiroyuki [Environment Department, Kyudensangyo Co., Inc., 2-18-20, Najima, Higashi-ku, Fukuoka 813-0043 (Japan)], E-mail: hiroyuki_hayakawa@kyudensangyo.co.jp; Nakashima, Satoshi [Environment Department, Kyudensangyo Co., Inc., 2-18-20, Najima, Higashi-ku, Fukuoka 813-0043 (Japan); Kusumoto, Junichi; Kanaya, Akihiro [Research Laboratory, Kyushu Electric Power Co., Inc., 2-1-47, Shiobaru, Minami-ku, Fukuoka 815-8520 (Japan); Nakashima, Hideharu [Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakouen, Kasuga-City, Fukuoka 816-8580 (Japan)

    2009-09-15

    To evaluate the creep deformation mechanism of heat resistant steel, stress change tests were conducted during creep tests for Modified 9Cr-1Mo Steel and 2.25Cr-1Mo Steel. In this study it was confirmed that the dislocation behavior during the creep tests was in viscous manner because of no instantaneous plastic strain observed at stress increments. Transient backward creep behavior was observed after stress reduction for these steels in this work. Mobilities of dislocation were evaluated by observed backward creep behavior after stress reductions. Internal stresses were evaluated by the changes of creep rate in stress increments. And mobile dislocation densities were evaluated with the estimated mobilities of dislocation and the changes of creep rate in stress increments. It was found that the variation of evaluated mobile dislocation densities during creep deformation showed the same tendency as the variation of creep rate. Therefore mobile dislocation density is the dominant factor that influences the creep rate variation in creep deformation of these steels in this work. The mobilities of dislocation showed a good correlation with 1/T and related with solute amount of Mo that is a solution hardening element.

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

    Science.gov (United States)

    Samson, R A; Houbraken, J; Varga, J; Frisvad, J C

    2009-06-01

    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 beta-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. zollerniae, 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 thus chemically 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. PMID:20198134

  3. Growth modelling of heat-resistant fungi: the effect of water activity.

    Science.gov (United States)

    Valík, L; Piecková, E

    2001-01-22

    Growth of three strains of heat-resistant fungi, Byssochlamys fulva, Neosartorya fischeri and Talaromyces avellaneus, was studied at 25 degrees C at eight or nine water activities (a(w)) adjusted with sucrose between 0.995 and 0.85. The flexible growth model of Baranyi describing the change in colony diameter (mm) with respect to time was first fitted to measured growth data and from the fitted curves the maximum colony growth rates were estimated. These values were fitted with respect to a(w) to predict colony growth rates at any a(w) within the range tested. Optimum a(w) values of 0.986, 0.985, and 0.990 for growth, and maximum colony growth rates of 12.6, 13.2 and 20.2 mm d(-1), respectively, were calculated. The time to reach a colony diameter of 3 mm and the optimum a(w) for each strain were also calculated. The results can be applied to the prevention of spoilage of canned fruit or juices and other heat processed fruit based products. PMID:11205942

  4. 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)

  5. 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.

  6. 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.

  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.

    Science.gov (United States)

    de Jong, Aarieke E I; van Asselt, Esther D; Zwietering, Marcel H; Nauta, Maarten J; de Jonge, Rob

    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. PMID:22389647

  9. 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)

  10. 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

  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. Neutralizing activity of monoclonal antibodies to heat-sensitive and heat-resistant epitopes of Rickettsia rickettsii surface proteins.

    OpenAIRE

    Anacker, R L; McDonald, G A; List, R. H.; Mann, R E

    1987-01-01

    Antiprotein monoclonal antibodies derived from mice inoculated with Rickettsia rickettsii heated at 56 degrees C for 15 min are of two types: one is type specific for epitopes denatured by moderate temperatures, and the other is specific for epitopes resistant to 100 degrees C for 5 min. The heat-resistant epitopes are found by immunoblotting on multiple polypeptides after solubilization of the rickettsiae at temperatures of 56 degrees C or higher. Most, but not all, antibodies to the heat-se...

  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. 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

  15. 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

  16. Electromagnetic property of SiO{sub 2}-coated carbonyl iron/polyimide composites as heat resistant microwave absorbing materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongyu, E-mail: wanghongyu07010310@163.com; Zhu, Dongmei; Zhou, Wancheng; Luo, Fa

    2015-02-01

    Heat resistant microwave absorbing materials were prepared by compression molding method, using polyimide resin as matrix and SiO{sub 2} coated carbonyl iron (CI) as filler. The SiO{sub 2} coated CI particles were prepared by Stober process. The microwave absorbing properties and the effect of heat treatment on the electromagnetic properties of SiO{sub 2} coated CI/polyimide composites were investigated. When the content of SiO{sub 2} 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 SiO{sub 2} coated carbonyl iron as filler. • The SiO{sub 2} coated CI shows good absorbing properties. • The composites have good heat resistance.

  17. 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

  18. 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.

  19. 17th colloquium on long-time behaviour of heat-resistant steels and high-temperature materials

    International Nuclear Information System (INIS)

    This volume contains 17 lectures on the following subjects (selection): Microstructural description of the creep behaviour of the Ni-based superalloy IN 738 LC based on the iso-structural model; the effect of Nb, V, N and Al on the creep rupture strength of 9-12% Cr steels; structure and long-time investigations of 9-12% Cr steels for forged and cast parts; creep tests on samples of welded pipe joints made of X10CrMo V Nb 9-1 steel, evolution of the microstructure during creep stress and annealing of the Martensitic cast steel G-X12 Cr Mo V Nb N 9 1; Micro-structure during cyclic creep in the creep area using the example of Martensitic steel X22 Cr Mo V 12 1; description of crack initiation and progress of hot cracks in heat resisting 1% Cr Mo V castings under creep or fatigue stress; optimisation and verification of creep equations for high temperature materials, single stage and multi-stage long-time creep fatigue behaviour of heat-resistant steels; cyclic creep behaviour of heat-resistant steels under intermittent stress and on the tension/compression area. (orig./MM)

  20. 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.

  1. 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.

  2. On evaluation of tensile stress-strain diagrams for heat resistant metallic materials

    International Nuclear Information System (INIS)

    Temperature and cyclic loading are experimentally studied for their effect on tensile stress-strain diagrams of high temperature nickel alloys. Four types of diagrams are singled out as dependent on the temperature level. It is shown that on the whole cyclic loadings decrease characteristics of the short-term strength. The effect of the tensile stress-strain diagram displacement towards hardening is revealed in the region of high temperatures as against under pure static loading

  3. 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.

  4. Oxidation of high-temperature alloys (superalloys) at elevated temperatures in air: I

    International Nuclear Information System (INIS)

    Four commercial alloys - Hastelloy C-4, alloy 1.4306S (SS 304L), Incoloy 800H, and Incoloy 825 - were studied for their oxidation behavior at elevated temperatures. Specimens were exposed to air from 600 to 1200 degree C for 1 to 400 hr. Reaction kinetics of oxidation were determined, and the morphology of the surface-oxide scales was investigated. Hastelloy C-4 showed better resistance to oxidation for exposure temperatures up to 1000 degree C in comparison with the other three alloys. In this temperature range, it follows a cubic rate law of oxidation due to formation of uniform, protective, and adherent oxide scales. The latter three alloys obeyed the parabolic rate law at 1000 degree C and 1200 degree C, but for lower temperatures a mixed behavior was shown. The oxide layer developed on the alloy 1.4306S was always in the form of stratified nodules/warts. For longer exposures the nodules joined each other to form continuous but discrete layers. Incoloy 800H and Incoloy 825 behaved in an almost identical manner, their reaction kinetics being governed by the parabolic rate law throughout the temperature range. Oxide spalling was observed at all temperatures. In contrast to Incoloy 800H the Incoloy 825 was totally oxidized for longer exposures at 1200 degree C. 16 refs., 12 figs., 1 tab

  5. 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

  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. Effects of gamma irradiation on two heat resistant moulds: Aspergillus fumigatus and Paecilomyces variotii isolated from margarine

    Science.gov (United States)

    Gumus, Tuncay; Gecgel, Umit; Demirci, A. Sukru; Arici, Muhammet

    2008-05-01

    The present study was undertaken to evaluate the effect of gamma irradiation on two heat-resistant moulds, namely Aspergillus fumigatus and Paecilomyces variotii isolated from margarine samples. The irradiation process of these moulds was carried out in a 60Co gamma ( ?) irradiator at average absorbed doses of 1, 3, 5 and 7 kGy for exposure times of 52, 156, 260 and 364 min, respectively. The average D10 value for A. fumigatus was 1.08±0.08 kGy while it was 0.59±0.10 kGy for P. variotii. Consequently, the sensitivity of P. variotii against ? irradiation was more than A. fumigatus.

  8. Effects of gamma irradiation on two heat resistant moulds: Aspergillus fumigatus and Paecilomyces variotii isolated from margarine

    International Nuclear Information System (INIS)

    The present study was undertaken to evaluate the effect of gamma irradiation on two heat-resistant moulds, namely Aspergillus fumigatus and Paecilomyces variotii isolated from margarine samples. The irradiation process of these moulds was carried out in a 60Co gamma (?) irradiator at average absorbed doses of 1, 3, 5 and 7 kGy for exposure times of 52, 156, 260 and 364 min, respectively. The average D10 value for A. fumigatus was 1.08±0.08 kGy while it was 0.59±0.10 kGy for P. variotii. Consequently, the sensitivity of P. variotii against ? irradiation was more than A. fumigatus

  9. 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

  10. Phase composition and structure of NiAl base alloys of Ni-Al-Co-M systems where M-Ti, Zr, Hf, V, Nb, Ta, Cr, Mo

    International Nuclear Information System (INIS)

    A study was made into the effect of transition metals (0.27-23 at.% of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo) on phase composition and microstructure of (? + ?)-alloys of the Ni-Al-Co system. It is concluded that for designing heat resistant nickel base alloys with the density not exceeding 7.3 g/cm3 the two-phase (? + ?) alloys can be taken as a basis. In alloys of the (29-43) Ni-(20-25)Al-(32-34)Co compositions with 1-1.8 at%Mo, Ta, Nb or V the occurrence of gamma'-phase secondary precipitations is shown to be possible. Ti and Cr contents may reach 3 and 12 at.% respectively. Alloying elements promote an increase of main strengthening element (Co) content in ?-phase and enhance heat resistance of Ni-Al-Co alloys. 3 refs.; 6 figs

  11. 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

  12. Development of Mg-Al-Zn based diecasting alloys for elevated temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.M.; Park, B.K.; Jun, J.H.; Kim, K.T.; Jung, W.J. [Advanced Materials Development Center, Korea Inst. of Industrial Technology, Incheon (Korea); Shin, K. [Dept. of Metallurgy and Materials Science, Changwon National Univ., Changwon (Korea)

    2005-07-01

    Effort has been devoted to develop new heat resistant diecasting alloys based on Mg-Al-Zn system in this research. Small amounts of cerium-rich misch metal and antimony additions to AZ91 alloy could enhance the tensile strength at an elevated temperature while keeping the good castability. The increase of Zn content in Mg-8(wt%)Al-xZn-0.5RE-0.5Sb alloys, was observed to significantly increase the yield strength at 175 C although the castability such as fluidity and hot cracking resistance was slightly decreased. Intensive microstructural investigation on the new Mg-Al-Zn diecasting alloys was also carried out. (orig.)

  13. 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.

  14. Heat-resistivity and local structure of new nuclear waste glass composed of calcium aluminate and lead phosphate

    International Nuclear Information System (INIS)

    Aluminophosphate glass with a batch composition of 30CaO·15Al2O3·5Fe2O3·25PbO·25P2O5 was prepared as a potential host for the high-level nuclear wastes. This ''base glass'' consists of highly heat-resistant 60CaO·(40-x)Al2O3·xFe2O3 glass and water-resistant lead metaphosphate glass, Pb(PO3)2, which is known to have -103 times higher water-resistivity than conventional borosilicate glass. Two crystallization temperatures (Tc) of 650-671 and 668-693 degC were determined from the differential thermal analysis (DTA) of the ''base glass''. Large activation energies of 4.2 and 4.9 eV were obtained from a Kissinger plot of the Tc values. Nuclear waste ''model glass'' containing 10 stable isotopes with the mass numbers of 90-100 (Sr, Y, Zr, Nb, Mo) and 135-145 (Ba, La, Ce, Pr, Nd) also shows high heat-resistivity. 57Fe Mossbauer spectrum indicates that Fe(III) and Fe(II) are ionically bonded to distorted PO4 tetrahedra at the sites of network modifier. (author)

  15. Air contamination effects on the compatibility of liquid lithium with molybdenum, TZM, niobium, stainless steels, nickel and Hastelloy N in stainless steel vessels at 6000C

    International Nuclear Information System (INIS)

    The effects of nonmetallic impurities on the compatibility of liquid lithium with molybdenum, TZM, niobium, type 304 and type 316 stainless steels, nickel and Hastelloy N were investigated. Three compatibility tests (test I, test II and test III), classified by the grade of air contamination of the lithium, were conducted at 6000C for about 1000 h in stainless steel vessels. In each test the above-mentioned specimens were immersed together in the lithium. In test I weight gain was observed for all the specimens except nickel and Hastelloy N. However, in test II and test III, weight loss was observed for all the specimens. MoNi3 was produced on the surface of the molybdenum and TZM specimens as a result of the reaction between molybdenum and nickel dissolved in the liquid lithium. NbNsub(0.9)Osub(0.1) was observed on the surface of niobium specimens in test I and test II, and Nb2N in test II and test III. The surface of the stainless steel specimens in test II and test III was depleted with nickel and chromium elements, and deteriorated. The corrosion rates of the test specimens in test III were about 2, 5, 26 and 22/?m/yr for molybdenum or TZM, niobium, type 304 stainless steel and type 316, respectively. Nickel and Hastelloy N were severely attacked by liquid lithium at 6000C. These results were obtained for liquid lithium with a high nickel concentration. (Auth.)

  16. 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.

  17. 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.

  18. Rolling contact fatigue behaviour of heat resistant bearing steels at high operational temperatures

    International Nuclear Information System (INIS)

    An approach was made to estimate the endurance limit in rolling contact fatigue in dependence of the operational conditions for the bearing steels M50 (AMS 6491), M50 NiL (AMS 6278) and the nitrogen-alloyed Cronidur 30 (AMS 5898) by investigating the changes in the residual stress profiles after 5 million cycles of over-rolling. Real main shaft bearings with a pitch diameter of 168 mm have been tested. To simulate the heat generated in the turbine engines even under boundary operational conditions oil inlet temperatures between 80 and 210 C have been applied, the rotational speed has been varied between 2500 and 14000 r/min and the interference fit has been changed to produce different hoop stress levels. (orig.)

  19. Corrosion studies and recommendation of alloys for an incinerator of glove-boxes wastes

    International Nuclear Information System (INIS)

    In the framework of the development of an incineration process for high chlorinated wastes, commercial alloys have been investigated by means of parametric laboratory tests in HCl containing gas mixtures and also in field tests. Recommendations may be formulated for the three main components i.e. pyrolyser, calciner and cooler. In very low oxygen-potential atmospheres, the alloys Hastelloy C276 and Inconel 625 present the best behaviours. For the calciner, alloy Inconel 601 is more satisfactory than AISI 310 steel. As for the cooler, only the alloy Haynes 214 appears acceptable at 1100 deg C. Because of the very low stress level affecting the components, thermomechanical properties do not modify these recommendations based on corrosion behaviour

  20. Response Surface Design Model to Predict Surface Roughness when Machining Hastelloy C-2000 using Uncoated Carbide Insert

    International Nuclear Information System (INIS)

    This paper presents to develop of the response surface design model to predict the surface roughness for end-milling operation of Hastelloy C-2000 using uncoated carbide insert. Mathematical model is developed to study the effect of three input cutting parameters includes the feed rate, axial depth of cut and cutting speed. Design of experiments (DOE) was implemented with the aid of the statistical software package. Analysis of variance (ANOVA) has been performed to verify the fit and adequacy of the developed mathematical model. The result shows that the feed rate gave the more effect on the both prediction values of Ra compared to the cutting speed and axial depth of cut. SEM and EDX analyses were performed in different cutting conditions. It can be concluded that the feed rate and cutting force give the higher impact to influence the machining characteristics of surface roughness. Thus, the optimizing the cutting conditions are essential in order to improve the surface roughness in machining of Hastlelloy C-2000.

  1. Ductility behaviour of high-temperature brazed joints of heat resistant materials

    International Nuclear Information System (INIS)

    The investigations, reported in this thesis, have been performed to describe the ductility joints, brazed with nickel base filler metals (L-Ni2 (2.4142); L-Ni5 (2.4148)), regarding the base-metal properties (X10CrNiNb 18 9 (1.4550); NiCr22Mo9Nb (2.4856). Metallurgical aspects as well as the influence of the brazing process have been taken into account. The effect of raised temperatures, as they occur under service conditions, on the ductility of brazed structures have been investigated determining the notch impact work-temperature graphs. Numerous metallographic and microanalytical investigations contributed to the characterisation of the brazed joint structures and its influence on the ductility. All investigated brazing combinations showed a strong temperature dependence. It was found furtheron, that beside freedom from brittle phases a well matched behaviour of elastic and plastic properties of the base metal and the brazed zone is a prerequisite for ductile joints. The determination of the ductility-behaviour of the investigated filler metal-base metal combinations may contribute to the replacement of high alloy steel based filler metals for dynamically stressed structures. This may cause a considerable reduction in costs and may lead to use high temperature brazing in conventioned industries more frequently. Data are given for brazing parameters to obtain optimized joints. (orig./MM)

  2. 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.

  3. 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

  4. High temperature ductility of austenitic alloys exposed to thermal neutrons

    International Nuclear Information System (INIS)

    Loss of high temperature ductility due to thermal neutron irradiation was examined by slow strain rate test in vacuum up to 10000C. The results on two heats of Hastelloy alloy X with different boron contents were analyzed with respect to the influence of the temperatures of irradiation and tensile tests, neutron fluence and the associated helium production due to nuclear transmutation reaction. The loss of ductility was enhanced by increasing either temperature or neutron fluence. Simple extrapolations yielded the estimated threshold fluence and the end-of-life ductility values at 900 and 10000C in case where the materials were used in near-core regions of VHTR. The observed relationship between Ni content and the ductility loss has suggested a potential utilization of Fe-based alloys for seathing of the neutron absorber materials

  5. Alloying of vacuum-melted tungsten

    International Nuclear Information System (INIS)

    Discussed is the possibility to lower the temperature of the plastic-brittle transition, to improve the technological plasticity of the melted tungsten through its alloying with the ZrC, HfC, NbC and TaC carbides and substituting elements. The mechanism of the solidly soluted strengthening in the alloys of the tungsten with rhenium and molybdenum are shown. Represented are the data, regarding the researches aimed at fixing the phase zones in the tungsten side of the W-C-Zr, W-C-Hf, W-C-Nb, W-C-Ta, W-C-Re and W-C-Os ternary. It is shown, that the tungsten alloys strengthening with the MeC-type disperse carbide-ensures a combination of the technological plasticity with good heat-resisting properties

  6. Effects of gamma irradiation on two heat resistant moulds: Aspergillus fumigatus and Paecilomyces variotii isolated from margarine

    Energy Technology Data Exchange (ETDEWEB)

    Gumus, Tuncay [Agricultural Faculty, Department of Food Engineering, 59030, Namik Kemal University, Tekirdag (Turkey)], E-mail: tuncaygumus@tu.tzf.edu.tr; Gecgel, Umit; Demirci, A. Sukru; Arici, Muhammet [Agricultural Faculty, Department of Food Engineering, 59030, Namik Kemal University, Tekirdag (Turkey)

    2008-05-15

    The present study was undertaken to evaluate the effect of gamma irradiation on two heat-resistant moulds, namely Aspergillus fumigatus and Paecilomyces variotii isolated from margarine samples. The irradiation process of these moulds was carried out in a {sup 60}Co gamma ({gamma}) irradiator at average absorbed doses of 1, 3, 5 and 7 kGy for exposure times of 52, 156, 260 and 364 min, respectively. The average D{sub 10} value for A. fumigatus was 1.08{+-}0.08 kGy while it was 0.59{+-}0.10 kGy for P. variotii. Consequently, the sensitivity of P. variotii against {gamma} irradiation was more than A. fumigatus.

  7. [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

  8. 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

  9. New structural high strength rationally alloyed steels

    International Nuclear Information System (INIS)

    New developments in high strength structural steels are reported. Properties and perspective fields of application are described for the following materials: austenitic chromium steels with ultra equilibrium nitrogen content, steels with nitrogen martensite structure, microalloyed ferritic-pearlitic steels with decreased concentrations of Mn and Ni, high ductility heat resisting steels, nonmagnetic chromium free Mn-Ni-Cu-V-C steels and iron powder alloys with superhard carbon phases. Steel 02Kh12G14N4YuM is recommended to be used for parts and assemblies of nuclear power plants

  10. Corrosion Behavior of Alloys in Molten Fluoride Salts

    Science.gov (United States)

    Zheng, Guiqiu

    The molten fluoride salt-cooled high-temperature nuclear reactor (FHR) has been proposed as a candidate Generation IV nuclear reactor. This reactor combines the latest nuclear technology with the use of molten fluoride salt as coolant to significantly enhance safety and efficiency. However, an important challenge in FHR development is the corrosion of structural materials in high-temperature molten fluoride salt. The structural alloys' degradation, particularly in terms of chromium depletion, and the molten salt chemistry are key factors that impact the lifetime of nuclear reactors and the development of future FHR designs. In support of materials development for the FHR, the nickel base alloy of Hastelloy N and iron-chromium base alloy 316 stainless steel are being actively considered as critical structural alloys. Enriched 27LiF-BeF2 (named as FLiBe) is a promising coolant for the FHR because of its neutronic properties and heat transfer characteristics while operating at atmospheric pressure. In this study, the corrosion behavior of Ni-5Cr and Ni-20Cr binary model alloys, and Hastelloy N and 316 stainless steel in molten FLiBe with and without graphite were investigated through various microstructural analyses. Based on the understanding of the corrosion behavior and data of above four alloys in molten FLiBe, a long-term corrosion prediction model has been developed that is applicable specifically for these four materials in FLiBe at 700ºC. The model uses Cr concentration profile C(x, t) as a function of corrosion distance in the materials and duration fundamentally derived from the Fick's diffusion laws. This model was validated with reasonable accuracy for the four alloys by fitting the calculated profiles with experimental data and can be applied to evaluate corrosion attack depth over the long-term. The critical constant of the overall diffusion coefficient (Deff) in this model can be quickly calculated from the experimental measurement of alloys' weight loss due to Cr depletion. While many factors affect the Deff such as the grain boundary type, grain size, precipitates, initial Cr concentration as well as temperature, this model provides a methodology for estimating corrosion attack depth of alloys in molten fluoride salts obviating the need for difficult and challenging experiment.

  11. 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.

  12. Reaction of several iron and nickel based alloys with sintered Li2O pellets

    International Nuclear Information System (INIS)

    The reaction of type 316 stainless steel, Incoloy 800, Hastelloy X-R, Inconel 600 and pure Ni with sintered Li2O pellets has been studied between 800 and 11000C under dynamic vacuum. The reaction products were analyzed by means of metallographic, microprobe and X-ray diffraction methods. The reactions proceeded measurably between 800 and 9500C and appreciably at 10000C, being greatest with Incoloy 800 and least with Hastelloy X-R. Among the primary alloy constituents, chromium was exclusively attacked by lithium and oxygen diffusing from the Li2O into the alloys to form LiCrO2. This phase grew into a reaction zone (subscale) of uniform thickness beneath the surface of each alloy. Preferential growth of LiCrO2 along the grain boundaries was observed only in the case of Inconel 600 below 9500C. On the other hand, iron diffused toward the Li2O pellets to form volatile Li5FeO4. However, any reaction product associated with Ni was not detected and Ni metal was little attacked by the Li2O pellet over the whole range of reaction temperature. (Auth.)

  13. 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 ...

  14. 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

  15. 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 %

  16. Microstructural analysis as the indicator for suitability of weld repairing of the heat resistant Cr - Ni steel

    Directory of Open Access Journals (Sweden)

    Odanovi?, Z.

    2010-08-01

    Full Text Available Metallurgical evaluation was performed on a fractured column tube of the reformer furnace in an ammonia plant. The tubes were manufactured from centrifugally cast heat resistant steel HK 40. Optical and scanning electron microscope (SEM were used for microstructural and fracture analysis. For composition determination of the microconstituents energy dispersive X ray spectroscopy (EDS was used. To evaluate mechanical properties, hardness and microhardness measurements were performed. Investigations based on the microstructural features with the idea to indicate suitability of weld repair of the column were performed in this study. It was observed that the crack initiation, caused by oxidation/corrosion and thermal stresses induced by temperature gradient, appeared in the inner side of the tube wall and propagation occurred along grain boundaries. The results clearly showed the presence of an irregular microstructure which contributed to crack propagation through the tube wall. An occurrence of precipitated needle-shaped carbides/carbonitrides and brittle ? phase was also identified in the microstructure. Results of the microstructural and fracture analysis clearly indicate that reformer furnace columns made of heat resistant steel HK 40 were unsuitable for weld repair.

    La evaluación metalúrgica se realizó en un tubo de columna con fracturas, que es parte del horno reformador en una planta de amoníaco. Estos tubos son fundidos centrífugamente y fabricados en acero resistente al calor, de tipo HK- 40. Para el análisis microestructural de la fractura se ha utilizado microscopía óptica y electrónica de barrido (SEM. La composición de los micro-constituyentes se determinó por espectrometría de rayos X de energía dispersiva (EDS. Las propiedades mecánicas se evaluaron mediante mediciones de microdureza Vickers. Las investigaciones en este estudio se han llevado a cabo con el fin de demostrar la idoneidad de reparación por soldadura de columnas en base a sus características micro-estructurales. Se ha observado que el inicio de la rotura, causada por el efecto de la oxidación/corrosión y el choque térmico ocasionado por el gradiente de temperatura, aparece en la pared interna del tubo y se propaga a lo largo de los bordes de grano. Los resultados demuestran la presencia de una microestructura irregular que contribuyó a la propagación de la rotura a lo largo de la pared del tubo. En la microestructura también se ha registrado la formación da la precipitación de fases de carburo/carbón nitrito que aparecen en forma de agujas y fase ? frágil. Con base en los resultados obtenidos, se puede concluir que la microestructura investigada no es idónea para aplicar la reparación por soldadura.

  17. High temperature corrosion of iron-base and nickel-base alloys for hydrogen production apparatus by thermochemical method in H2O+SO3 atmosphere

    International Nuclear Information System (INIS)

    Corrosion tests for ten iron-base and nickel-base alloys at 850degC for 1000h in H2O + SO3 atmosphere were carried out to obtain data for selection of candidate container materials in the thermochemical process which produces hydrogen from water by use of iodine and sulfur as circulating materials. The following results were obtained: (1) Oxidation, spallation of corrosion film, uniform corrosion and grain boundary penetration composed of internal oxidation and sulfuration occur in this atmosphere and the corrosion proceeds by grain boundary penetration. (2) SUS304, SUS316 and Hastelloy C276 are inferior in corrosion resistance and SUS329J4L is superior among ten alloys used in this experiment. Alloys such as Alloy 800H and Hastelloy XR show intermediate corrosion resistance. (3) Oxide films of alloys containing iron and chromium are mostly composed of outer iron-oxide and inner chromium-oxide. Sulfur concentrates at scale/metal interfaces and grain boundary penetration portions, and sulfides form. (4) Corrosion in this atmosphere could be expressed using the parabolic law between the grain boundary penetration depth and time. It is considered that causes of the apparently observed parabolic law were a high concentration of SO3 and change of the gas composition caused by catalytic action of the corrosion film formed with the progress of corrosion. (author)

  18. 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

  19. Effect of normalizing temperature on the strength of 9Cr–3W–3Co martensitic heat resistant steel

    International Nuclear Information System (INIS)

    Microstructure and room temperature strength of 9Cr–3W–3Co martensitic heat resistant steel after normalizing at 900–1200 °C for 1 h and then tempering at 750 °C for 1 h have been experimentally investigated using optical microscope (OM), field emission scanning electron microscope (FESEM), electron back-scattered diffraction (EBSD), field emission transmission electron microscope (FETEM) and tensile tests. The results show that with increasing normalizing temperature, the strength of the 9Cr–3W–3Co steel increases from 900 °C to 1000 °C, then keeps almost the same from 1000 °C to 1100 °C and finally increases again from 1100 °C to 1200 °C. The change in the room temperature strength can mainly be attributed to the change in precipitation strengthening. The size and the amount of particles after tempering are mainly due to the re-dissolution of particles during normalization. The higher the normalizing temperature is, the more the coarse particles formed during manufacturing will be re-dissolved, and then the larger the amount of fine particles precipitated during tempering is

  20. 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

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

    Science.gov (United States)

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

    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 improved electrolyte uptake, better interface stability and enhanced ionic conductivity. In addition, the lithium cobalt oxide (LiCoO2)/graphite cell using this composite separator exhibited better rate capability and cycling retention than that for PP separator owing to its facile ion transport and excellent interfacial compatibility. Furthermore, the lithium iron phosphate (LiFePO4)/lithium cell with such composite separator delivered stable cycling performance and thermal dimensional stability even at an elevated temperature of 120°C. All these fascinating characteristics would boost the application of this composite separator for high-performance lithium ion battery. PMID:24488228

  2. 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

  3. 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

  4. Screening foods for processing-resistant bacterial spores and characterization of a pressure- and heat-resistant Bacillus licheniformis isolate.

    Science.gov (United States)

    Ahn, Juhee; Balasubramaniam, V M

    2014-06-01

    This study was carried out to isolate pressure- and heat-resistant indicator spores from selected food matrices (black pepper, red pepper, garlic, and potato peel). Food samples were processed under various thermal (90 to 105°C) and pressure (700 MPa) combination conditions, and surviving microorganisms were isolated. An isolate from red pepper powder, Bacillus licheniformis, was highly resistant to pressure-thermal treatments. Spores of the isolate in deionized water were subjected to the combination treatments of pressure (0.1 to 700 MPa) and heat (90 to 121°C). Compared with the thermal treatment, the combined pressure-thermal treatments considerably reduced the numbers of B. licheniformis spores to less than 1.0 log CFU/g at 700 MPa plus 105°C and at 300 to 700 MPa plus 121°C. The inactivation kinetic parameters of the isolated B. licheniformis spores were estimated using linear and nonlinear models. Within the range of the experimental conditions tested, the pressure sensitivity (zP) of the spores decreased with increasing temperature (up to 121°C), and the temperature sensitivity (zT) was maximum at atmospheric pressure (0.1 MPa). These results will be useful for developing a combined pressure-thermal inactivation kinetics database for various bacterial spores. PMID:24853517

  5. 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.

  6. 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.

  7. 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)

  8. Development of powder metallurgy Al alloys for high temperature aircraft structural applications, phase 2

    Science.gov (United States)

    Chellman, D. J.

    1982-01-01

    In this continuing study, the development of mechanically alloyed heat resistant aluminum alloys for aircraft were studied to develop higher strength targets and higher service temperatures. The use of higher alloy additions to MA Al-Fe-Co alloys, employment of prealloyed starting materials, and higher extrusion temperatures were investigated. While the MA Al-Fe-Co alloys exhibited good retention of strength and ductility properties at elevated temperatures and excellent stability of properties after 1000 hour exposure at elevated temperatures, a sensitivity of this system to low extrusion strain rates adversely affected the level of strength achieved. MA alloys in the Al-Li family showed excellent notched toughness and property stability after long time exposures at elevated temperatures. A loss of Li during processing and the higher extrusion temperature 482 K (900 F) resulted in low mechanical strengths. Subsequent hot and cold working of the MA Al-Li had only a mild influence on properties.

  9. Efficiency of two-stage ion-plasma technology of production of alloyed diffusion aluminide coatings on the Ni-based superalloys

    International Nuclear Information System (INIS)

    A consideration is given to diffusion ion-plasma coatings produced according to a two-stage technology with the use of three nickel alloys of a Ni-Cr-Al-Y system doped with tantalum, tungsten, rhenium and two aluminium alloys doped with nickel, yttrium, silicon. The structure, chemical and phase compositions of coatings on heat resistant nickel base alloys ZhS6U, ZhS26, ZhS32 are investigated depending on initial alloy layer thickness. It is shown that the two-stage coating technology permits a considerable enhancement of operational properties of the coatings

  10. The effect of miced plasticizer on radiation crosslinking of wire and cable materials for heat resistant 105 deg C polyvinyl chloride

    International Nuclear Information System (INIS)

    To prepare 105 deg C heat resistant PVC wire and cable, the ester of trimellitic acid are generally used by its plasticizer, for example TOTM and NODTM etc., but the price of this kind of plasticizer is higher. For the sake of depression of quantity of TOTM, in present work, the effect of mixer of TOTM and ESBO (epoxide soyabean oil) on the properties of radiation crosslinked wire and cable for 105 deg C heat resistant PVC has been studied. From mechanical, electric properties and thermal stability of wire and cable with different ratio TOTM/ESBO, it may be known that the radiation crosslinked wire and cable will possess better synthetic properties, when the usable quantity of ESBO is an qppropriate amount

  11. 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

  12. 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

  13. Devising and producing nickelless and economically alloyed nickel steels for boiler equipment

    Energy Technology Data Exchange (ETDEWEB)

    Ryabchenkov, A.V.; Kuznetsov, E.V.; Chechel' , L.A.; Parshin, Yu.N.

    1987-11-01

    On the basis of theoretical investigations of the corrosive effect of the combustion products of natural organic fuel on structural materials, compositions of the chromium-manganese steels economically alloyed with nickel and also of nickelless chromium steels were devised at the Scientific and Production Association TsNIITMash; under the conditions of combustion of aggressive fuel, these steels are more heat resistant than ordinary chrome-nickel austenitic steels.

  14. Effect of creep deformation on the microstructural evolution of 11CrMoVNb heat resistant steel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.H.; Park, D.B. [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Kwun, S.I.; Huh, J.Y. [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Suh, J.Y.; Shim, J.H. [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Jung, W.S., E-mail: wsjung@kist.re.kr [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of)

    2012-02-28

    Highlights: Black-Right-Pointing-Pointer The coarsening rate of the precipitates was accelerated by applied stress. Black-Right-Pointing-Pointer The coalescence of martensite laths was accelerated by applied stress. Black-Right-Pointing-Pointer The Laves phase and Z-phase were not observed after creep. Black-Right-Pointing-Pointer The predicted size of MX precipitates by MatCalc agreed well with measured size. - Abstract: The effect of creep deformation on the microstructural evolution of an 11CrMoVNb ferritic heat resistant steel during high temperature creep tests was investigated. The creep test was performed within a temperatures range from 593 to 621 Degree-Sign C under different stress levels. For the detailed understanding of precipitate coarsening behavior, transmission electron microscopy (TEM) was used to analyze thin foils and replica films obtained from the crept specimens. The major precipitates were found to be M{sub 23}C{sub 6}, MX and Cr{sub 2}N phases and there was no change in precipitation sequence during creep. Coarsening behavior of the precipitates and growth behavior of martensite laths of the crept specimens were carefully examined in both regions of the grip and gage parts of the specimens in order to identify the effect of creep deformation. On the whole, precipitate size increased with increasing creep rupture time. On the other hand, precipitate coarsening and martensite lath widening were pronounced in the gage part compared to those in the grip part. This suggests that the creep deformation accelerates the rates of precipitate coarsening and martensite lath widening.

  15. 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

  16. 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.)

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

    OpenAIRE

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

    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...

  18. [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

  19. Influence of alloying elements on the chlorination behavior of nickel- and iron-based alloys

    International Nuclear Information System (INIS)

    A wide range of commercial heat-resistant alloys has been tested in a H2 + 10% HCl environment at 550 C, 650 C, 680 C, 750 C and 850 C. The tests were carried out using a 24 h cycle with a total test time of up to 1,056 H. Weight change was determined, and the average value for three specimens per alloy and temperature plotted versus time, followed by a metallographic examination of the depth of corrosion. By a statistical evaluation of the data generated, it was possible to describe the weight change and penetration depth of all the alloys under examination as a function of the concentration of their main alloying elements and test temperature. According to these results, alloying elements nickel and molybdenum have a beneficial influence on chlorination resistance, whereas silicon and titanium are detrimental. Increased temperature always resulted in enhance corrosion. Only Ni, Ni-Mo, and Ni-Cr-Mo alloys show acceptable resistance for temperatures up to 850 C

  20. Effect of carbon and niobium on the microstructure and impact toughness of a high silicon 12% Cr ferritic/martensitic heat resistant steel

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Zhongfei [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Wang, Pei, E-mail: pwang@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Li, Dianzhong [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Zhang, Yutuo [Shenyang Ligong University, 6 Nanping Road, Shenyang 110159 (China); Li, Yiyi [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

    2014-10-20

    In order to guide the design of 9–12% Cr ferritic/martensitic (F/M) heat resistant steels appropriate for use in accelerator-driven system, the impact toughness and behavior of precipitation of a 12% Cr F/M heat resistant steel containing high C and Si concentrations have been investigated. Particular focus has been given to the interaction of carbon and carbonitride-forming element. Because of the presence of primary NbC and a large amount of M{sub 23}C{sub 6}, the impact toughness of the investigated steel was much lower than that of the commercial 9–12% Cr F/M heat resistant steels. The primary NbC crystallizes directly from liquid metal when the Nb concentration is higher than a critical value. The critical value of Nb decreases with increase in the carbon concentration. In addition, the higher content and faster precipitation kinetics of M{sub 23}C{sub 6} in the investigated steel during the tempering heat treatment also lowers the impact toughness.

  1. 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.)

  2. 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

  3. Effect of carbon and niobium on the microstructure and impact toughness of a high silicon 12% Cr ferritic/martensitic heat resistant steel

    International Nuclear Information System (INIS)

    In order to guide the design of 9–12% Cr ferritic/martensitic (F/M) heat resistant steels appropriate for use in accelerator-driven system, the impact toughness and behavior of precipitation of a 12% Cr F/M heat resistant steel containing high C and Si concentrations have been investigated. Particular focus has been given to the interaction of carbon and carbonitride-forming element. Because of the presence of primary NbC and a large amount of M23C6, the impact toughness of the investigated steel was much lower than that of the commercial 9–12% Cr F/M heat resistant steels. The primary NbC crystallizes directly from liquid metal when the Nb concentration is higher than a critical value. The critical value of Nb decreases with increase in the carbon concentration. In addition, the higher content and faster precipitation kinetics of M23C6 in the investigated steel during the tempering heat treatment also lowers the impact toughness

  4. 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.

  5. 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.

  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. Electrochemical corrosion studies on metallic packaging materials for high-level waste. Behavior of Hastelloy C 4 in quinary brine and 1 M NaCl solutions

    International Nuclear Information System (INIS)

    The temperature dependent current density - potential behavior of Hastelloy C 4 in Q-brine is determined for T=250C and T=900C. The material gets passivated instantaneously. The stability of the protecting passivated layer is greatly reduced at T >= 550C to 600C. Some of the specimens differ greatly from each other in their behavior which is attributed to inhomogeneities in the structure and composition of the materials. The results obtained from the electrochemical corrosion studies make evident a clear effectiveness of various impurities and radiolytic products potentially occurring in brines produced in an accident. These impurities and radiolytic products cause a destruction of this material through local corrosion depending on their concentration and time. (orig./PW)

  8. Constitutive equations for the creep behaviour of nickel-base alloys for HTR components in the temperature range 1023-1273 K

    International Nuclear Information System (INIS)

    The applicability and modification of constitutive equations for describing the creep and relaxation behaviour of the nickel-base alloys INCONEL 617, NIMONIC 86 and HASTELLOY S have been investigated. Creep tests at stresses in range 10-150 MPa and temperatures in the range 1023-1273 K were carried out for the three alloys and in addition for INCONEL 617 and HASTELLOY S relaxation and stress dip tests in the stress range 10-170 MPa and temperature range 1073-1223 K were performed. The fitting of various creep equations to the measured creep curves showed that the best description of the primary and secondary creep regions was given by the equation formulated by Li. Under the experimental conditions used, dislocation climb was the dominant deformation mechanism. Using the internal stress concept to account for the resistance to deformation, a Norton creep law exponent of 3 for INCONEL 617 was derived which is in agreement with the value calculated by Weertman for dislocation climb controlled screep in solid solutions. For HASTELLOY S a lower value was observed. The dependence of the internal stress in the temperature and stress range on creep strain, applied stress, deformation prior to testing, temperature and alloy composition was determined. Relaxation and stress dip tests showed two separate time dependent relationships for the reduction of stress or anelastic backstrain. A rapid decrease at the start of the test due to back glide of dislocations and a much slower decrease associated with recovery were observed. Calculation of the stress relaxation behaviour based on the Norton creep law alone led to a time dependence which was not reflected in the experimental results. However, taking into account the internal stress which decreases during the relaxation test due to recovery processes, it was possible to describe satisfactorily the experimentally determined relaxation curves. (orig.)

  9. A study of the formation of tungsten-carbide surface alloyed layer on high carbon steel by Co2 laser

    International Nuclear Information System (INIS)

    In order to improve the wear- and heat-resistance of high carbon steel, a surface alloyed layer was created on a SK-3 steel with tungsten carbide by irradiation of Co2 layser. The object of this work was to investigate the effects of powder size and coating thickness of tungsten carbide, and the heat treatment on the mechanical properties of the laser surface alloyed layser. The results showed that tungsten carbide was distributed homogeneously throughout the alloyed layser. The amount of tungsten and hardness in alloyed layser were dependent upon the powder size and the thickness of coated layer. When alloyed layser was formed by overlapping laser tracks, and microhardness of this region decreased slightly. When the specimen was heat treated, the microhardness tended to increase depending upon the amount of tungsten in the alloyed layer. (Author)

  10. Low temperature oxidation of niobium alloy with silicon-aluminium coating

    International Nuclear Information System (INIS)

    Using the gravimetry methods heat resistance of niobium-titanium-aluminium alloy in the air and at 700 deg C in the initial state and when it is protected by silicide-aluminium coatings (with variable content of aluminium) is investigated. Using X-ray diffraction and micro X-ray diffraction analyses, mechanisms of the alloy oxidation and the coating protective effect are studied. The role of aluminium in the formation of coatings is analyzed and according to bend tests the plasticity of the coatings is evaluated

  11. Application of high nickel alloys in the field of experience within corrosion resistance protection in flue gas desulphurization plants absorbers

    International Nuclear Information System (INIS)

    Absorbers are the main components of flue gas desulphurization plants for 360 MW power-generating units in Belchatow Power Plant. The whole plant operating cycle and its service life depend on the type of materials applied for corrosion resistance lining of various absorber zones. RAFAKO S.A. activities within this field are focused on the extension of FGD plant service life via implementation of technology of lining the cylindrical part of absorber with 0,5 - 1,6 mm thickness sheets made of Hastelloy type alloys of C-22 and C-2000 grade. The experiment carried out on Hastelloy C-22 and C-2000 alloy grades enabled the assessment of corrosion resistance properties of base material, lining plates, weld joints and HAZ. The paper contains the results of weld joints and HAZ structure assessment, weld joints corrosion resistance characteristics, results of corrosion products examinations as well as requirements and recommendations concerning the execution of weld joints, lining steel surface preparation for welding, etc. (authors)

  12. 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.

  13. 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

  14. ??????? ???????????????????? ????????? ?? ?????? ? ????????? ???????????? ???????? ?? ???????????????? ??????????? ?????????? ?????? HIGH-TEMPERATURE OXIDATION INFLUENCE ON COMPOSITION AND STRUC-TURE OF ALUMINIDE COATING ON ION IMPLANTED SURFACE OF NICKEL ALLOY

    Directory of Open Access Journals (Sweden)

    ?. ?. ?????

    2013-01-01

    Full Text Available ??????????? ??????? ???????????????????? ????????? ?? ?????? ? ????????? ????????-??????????? ???????? ????-11, ??????????? ?? ???????? ?? ?????? ???-7?, ???????????????? ?????? ????????. ??????? ????????????????? ????????? ? ???????? ? ?????????? ?????????? ???????? ??? ??????????? 850 ??, ???????? ??????????? ????? ?????????? ????????????? ????????? ? ?????????????????? ????????? ????????. ???????? ???????????? ????????????? ?????? ??????????? ??? ??????? ?????????????? ?????????? ??????????? ?????????? ?????? ??? ????????-?????????? ????????, ?????????????? ????????? ????????????? ??????????? ??????.The paper discusses the influence of high-temperature oxidation on composition and structure of vacuum-plasma coating VSDP-11 deposited on TsNK-7P alloy substrate implanted with ytterbium  ions. The elements redistribution in the coating after exposition at 850 oC was studied and the interdependence between the elements redistribution and the life cycle of the protective coating was established. The ion implantation benefits resulting in the increase of the alloy surface heat resistance were shown for the additional nickel alloy surface treatment for the purpose of vacuum-plasma coating deposition.

  15. Spray pyrolysis of MgO templates on Hastelloy C276 and 310-austenitic stainless steel substrates for Y Ba2Cu3O7 (YBCO) deposition by pulsed laser deposition

    International Nuclear Information System (INIS)

    MgO thin films were deposited on Hastelloy C276 (HC) and 310 austenitic stainless steel by the spray pyrolysis technique, using magnesium nitrate and magnesium acetate as precursors. Thermogravimetrical analysis of the decomposition of the precursors was used to provide a guideline temperature for the thin film deposition. It was suggested that an amorphous MgO thin film was deposited on both 310-stainless steel and Hastelloy C-276 when using low concentration of the magnesium nitrate precursor. Higher concentrations were needed to obtain (200) oriented MgO films on C276. However, 310-stainless steel was found to not be a suitable substrate for MgO thin film deposition due to surface instability. A (200) oriented MgO thin film was grown on Hastelloy C276 using a magnesium acetate precursor at a much lower concentration compared to the nitrate precursor. The characterization of the thin films was done using scanning electron microscopy, x-ray photoelectron spectroscopy, atomic force microscopy, x-ray diffraction 2?-scans, rocking curves (?-scans), and pole figure measurements. MgO was found to have a very weak in-plane texture.

  16. Effect of vanadium addition on the creep resistance of 18Cr9Ni3CuNbN austenitic stainless heat resistant steel

    International Nuclear Information System (INIS)

    Highlights: •The first observation of V-rich Z-phase in austenitic stainless steel. •Separate precipitation of Nb-rich MX and V-rich Z-phase in Nb and V contained steel. •The effect of nanometer sized Z-phase on the improvement of creep strength. •The predicted size of MX precipitates by MatCalc agreed well with measured size. -- Abstract: The effect of vanadium addition on the creep property of niobium-containing 18Cr–9Ni austenitic heat-resistant steel was studied. After solution treatment, the MX precipitates of vanadium-free steel contained Nb only. On the contrary, high Nb and low V contents were detected from the MX precipitates in the steel with 0.3 wt% of vanadium. Vanadium-rich MX carbo-nitride was not observed in the matrix and at the grain boundaries after solution treatment. The vanadium precipitated as a form of Z-phase during early-stage creep deformation was attributed to the improvement in creep strength at 700 °C with applied stress higher than 150 MPa. And metallic Cu precipitates were confirmed in the nanometer scale using TEM and EDS technique. The Cu precipitates are believed to contribute to the strengthening of austenitic heat resistant steel independently. The precipitation behavior is discussed using transmission electron microscopy and thermo-kinetics simulation technique

  17. Phase analysis of high-temperature alloys for nuclear application by interference layer metallography

    International Nuclear Information System (INIS)

    Heat-resistant metallic materials for use in hightemperature gas-cooled reactors are nickel- or ironbase, solid-solution-strengthened, or age-hardened alloys. To control the material behavior and to adapt it to realistic load conditions, they have to be tested and characterized. During recent years, interference layer metallography has become an independent characterization procedure as well as an outstanding method for sample preparation for the application of quantitative image analysis to these refractory alloys. The special problems of characterization of nickel- and iron-base alloys that can now be solved by interference layer metallography and its physical backround are reported. Chromatic contrasting and the subsequent phase analysis by way of the example of three common alloys are discussed. Finally, the optimization of interference layer metallography for application in quantitative image analysis is described

  18. 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.

  19. Microstructure and Wear Behavior Of as Cast Al-25mg2si-2cu-2ni Alloy

    Directory of Open Access Journals (Sweden)

    1Geetanjali.S.Guggari ,

    2015-09-01

    Full Text Available The remarkable feature of the Aluminium is its low density and ability to withstand corrosion effect due to phenomenon of passivation. Structural components made from Aluminium and its alloys are vital to the aerospace industry and are important in other areas of transportation and structural materials. The oxides and sulphate are useful compounds of Aluminium based on its weight. In this work, an attempt has been made to utilize the combined effect of high cooling rate solidification, unique micro structural evolution mechanism of T6 heat treatment the advantages of hypereutectic Al-Si system alloyed with other elements such as Cu, Fe and Mg. In the present investigation, the binary alloys in the hypereutectic range viz. Al25Mg2Si has been selected as heat resistant Al-Si alloys. A systematic approach has been carried out to explore the micro structural features, mechanical and wear properties of as cast alloys.

  20. 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

  1. Investigation of corrosion and analysis of passive films concerning some nickel alloys and stainless steels in reconstructed geological environments

    International Nuclear Information System (INIS)

    This research thesis addresses the corrosion behaviour of materials which might be used for the fabrication of radioactive waste containers. After a bibliographical study on films formed on Fe-Cr-Ni alloys, this research concentrates on passivation and de-passivation phenomena of three nickel-base alloys among the most resistant to corrosion and which also meet processing and economic criteria: Hastelloy C4, Inconel 625 and ZICNDU 25-20. Titanium and Ti-Pd alloy are also studied. Parameters governing pitting corrosion are notably studied. After a recall of knowledge on passive films formed on Fe-Cr-Ni alloys, and a presentation of experimental and technical conditions, the author reports and discussed the results obtained by electrochemical studies, reports the determination of factors governing alloy passivation in geological waters. The influence of some soluble impurities is notably studied. The author reports the analysis by glow discharge optical emission spectrometry to determine the composition of passive films with respect to geological water nature, the immersion duration and the electrode potential. Additional surface analyses are performed by X-ray photoelectron spectrometry (XPS or ESCA) and secondary ion mass spectrometry (SIMS). Finally, the author uses a dosing method by neutron radio-activation of alloy elements to determine dissolution mechanisms

  2. 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.

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

    Science.gov (United States)

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

    2015-02-01

    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 characteristics enable the 3D porous skeleton to own several favorable properties, including superior thermal stability, good wettability with liquid electrolyte, high ion conductivity and internal short-circuit protection function, etc. which give rise to acceptable battery performances. Considering the simply and cost-effective preparation process, the porous membrane is deemed to be an interesting direction for the future lithium ion battery separator.

  4. Fire and heat resistant laminating resins based on maleimido and citraconimido substituted 1-(diorgano oxyphosphonyl) methyl -2,4- and -2,6- diaminobenzenes

    Science.gov (United States)

    Mikroyannidis, John A. (inventor); Kourtides, Demetrius A. (inventor)

    1987-01-01

    A class of fire and heat resistant bisimide resins prepared by thermal polymerization of maleimido or citraconimido substituted 1-((dialkoxyphosphonyl) methyl)-2-4 and -2,6-diaminobenzenes are described. The polymer precursors are prepared by reacting 1-((diorganooxyphosphonyl) methyl)-2-4 and -2,6-diaminobenzenes with maleic anhydride or citraconic anhydride in a mole ratio 1:2. Chain extension of the monomers is achieved by reacting the mono-N-maleimido derivatives of 1-((diorganooxyphosphonyl) methyl)-2,4 and -2,6-diaminobenzenes with aryl tetracarboxylic dianhydrides, such as benzophenone tetracarbocylic dianhydride, or aryl diisocyanates, such as methylenebis (4-phenylisocyanate), in a mole ratio 2:1. The polymerization of the monomers is studied by differential scanning calorimetry (DSC) and the thermal stability of the polymers is ascertained by thermogravimetric analysis (TGA).

  5. Fire and heat resistant laminating resins based on malemeido and citraconimido substituted 1 -2,4- and -2,6- diaminobenzenes

    Science.gov (United States)

    Mikroyannidis, John A.; Kourtides, Demetrius A. (02inventors)

    1987-01-01

    A novel class of fire and heat resistant bisimide resins prepared by thermal polymerization of maleimido or citraconimido substituted 1-(dialkox phosphonyl) methyl-2-4 and -2,6-diamino benzenes was presented. The polymer precursors are prepared by reacting 1-(diorgano oxyphosphonyl) methyl-2-4- and -2,6-diamino benzenes with maliec anhydride or citraconic anhydride in a mole ratio 1:2. Chain extension of the monomers is achieved by reacting the mono-N-maleimido derivaties of 1 (diorgano oxyphosphonyl) methyl -2,4- and -2,6-diamino benzenes with aryl tetracarboxylic dianhydrides, such as benzophenone tetracarboxylic dianhydride, or aryl diisocyanates, such as methylene bis(4-phenyl isocyanate), in a mole ratio 2:1. The polymerization of the monomers is studied by diferential scanning calorimetry and the thermal stability of the polymers is ascertained by thermogravimetric analysis.

  6. 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

  7. 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

  8. Low-cycle fatigue of two austenitic alloys in hydrogen gas and air at elevated temperatures

    Science.gov (United States)

    Jaske, C. E.; Rice, R. C.

    1976-01-01

    The low-cycle fatigue resistance of type 347 stainless steel and Hastelloy Alloy X was evaluated in constant-amplitude, strain-controlled fatigue tests conducted under continuous negative strain cycling at a constant strain rate of 0.001 per sec and at total axial strain ranges of 1.5, 3.0, and 5.0 percent in both hydrogen gas and laboratory air environments in the temperature range 538-871 C. Elevated-temperature, compressive-strain hold-time experiments were also conducted. In hydrogen, the cyclic stress-strain behavior of both materials at 538 C was characterized by appreciable cyclic hardening at all strain ranges. At 871 C neither material hardened significantly; in fact, at 5% strain range 347 steel showed continuous cyclic softening until failure. The fatigue resistance of 347 steel was slightly higher than that of Alloy X at all temperatures and strain ranges. Ten-minute compressive hold time experiments at 760 and 871 C resulted in increased fatigue lives for 347 steel and decreased fatigue lives for Alloy X. Both alloys showed slightly lower fatigue resistance in air than in hydrogen. Some fractographic and metallographic results are also given.

  9. 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)

  10. Compatibility of graphite with a martensitic-ferritic steel, an austenitic stainless steel and a Ni-base alloy up to 1250 C

    International Nuclear Information System (INIS)

    To study the chemical interactions between graphite and a martensitic-ferritic steel (1.4914), an austenitic stainless steel (1.4919; AISI 316), and a Ni-base alloy (Hastelloy X) isothermal reaction experiments were performed in the temperature range between 900 and 1250 C. At higher temperatures a rapid and complete liquefaction of the components occurred as a result of eutectic interactions. The chemical interactions are diffusion-controlled processes and can be described by parabolic rate laws. The reaction behavior of the two steels is very similar. The chemical interactions of the steels with graphite are much faster above 1100 C than those for the Ni-base alloy. Below 1000 C the effect is opposite. (orig.)

  11. Bimetallic layered castings alloy steel – grey cast iron

    Directory of Open Access Journals (Sweden)

    T. Wróbel

    2011-04-01

    Full Text Available Purpose: In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation.Design/methodology/approach: Prepared bimetallic layered castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. pearlitic grey cast iron, whereas working part (layer is depending on accepted variant plates of alloy steels sort X6Cr13, X12Cr13, X10CrNi18-8 and X2CrNiMoN22-5-3. The ratio of thickness between bearing and working part is 8:1. The verification of the bimetallic layered castings was evaluated on the basis of ultrasonic NDT (non-destructive testing, structure and macro- and microhardness researches. Moreover was made computer simulation of solidification of bimetallic layered casting in NovaFlow&Solid software.Findings: The results of studies and their analysis show efficiency of new, innovative technology of corrosion and heat resisting layered castings.Research limitations: In further research, authors of this paper are going to application of different material on bearing part of bimetallic layered casting.Practical implications: Prepared bimetallic layered castings according to work out technology can work in conditions, which require from working surface layer of element a high heat resistance and/or corrosion resistance in medium for example of industrial water.Originality/value: The value of this paper resides in new effective method of manufacture of heat resisting castings, mainly for lining of quenching car to coke production

  12. 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

  13. Materials for high temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    The main components of high temperature gas-cooled reactors, for which heat resistant alloys are used, are high temperature structural materials such as the heating tubes of intermediate heat exchangers and the liners of pipings and the material for cladding control rods. In this report, only the heat resistant alloys for high temperature structures, which involve many material engineering problems peculiar to high temperature gas-cooled reactors, are described. The main characteristics generally considered in the heat resistant alloys used for high temperature structures are creep and creep rupture characteristics, high cycle and low cycle fatigue, creep-fatigue interaction, the effect of thermal ageing on short time properties, creep ratchet characteristics, creep buckling characteristics, and the environmental effect by helium containing impurities of a minute amount. The heat resistant alloys which approach the condition of the practical use for high temperature structures are Alloy 800 H for 800-850 deg C, Hastelloy XR for 900-950 deg C and Inconel 617 for 950 deg C. The present state of developing high performance materials in various countries is reported. Also the examples of using graphite and carbon materials for high temperature gas-cooled reactors are described. (K.I.)

  14. High frequency fatigue test of IN 718 alloy – microstructure and fractography evaluation

    OpenAIRE

    Belan, J.

    2015-01-01

    INCONEL alloy 718 is a high-strength, corrosion-resistant nickel chromium material used at -253 °C to 705 °C for production of heat resistant parts of aero jet engine mostly. The fatigue test provided on this kind materials were done via low frequency loading up to this time. Nowadays, needs of results at higher volume of loading cycles leads to high frequency loading with aim to shorten testing time. Fatigue test of experimental material was carried out at frequency 20 kHz with stress ration...

  15. Field experience with the use of forged first-stage rotor blades made of EP800 nickel alloy for the GTE-45 gas turbine

    Science.gov (United States)

    Klypina, A. M.; Trushechkin, V. P.; Chistyakova, L. D.; Kazanskii, D. A.

    2008-02-01

    We present the results from an investigation of the structure, mechanical, and heat-resistant properties the metal of forged first-stage rotor blades of the GTE-45 gas turbine of NPO Turboatom after they had been in operation for a long time at the Yakutsk district power station. It is shown that blades made of this alloy may operate for as long as 60000 h provided that they have been manufactured with good quality. Criteria for the operational reliability of EP800 alloy are developed.

  16. 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.

  17. Creep property of carbon and nitrogen free high strength new alloys

    International Nuclear Information System (INIS)

    The carbon and nitrogen free new alloys which were composed of supersaturated martensitic microstructure with high dislocation density before the creep test have been investigated systematically. These alloys were produced from the new approach which raised creep strength by the utilization of the reverse transformed austenite phase as a matrix and intermetallic compounds such as Laves phase and mu-phase as precipitates during heating before the creep test. It is important that these alloys are independent of any carbides and nitrides as strengthening factors. The high temperature creep test over 700 oC exceeds 50,000 h, and the test is continuous. Creep behavior of the alloys is found to be different from that of the conventional high-Cr ferritic steels. The addition of boron to the alloy pulled the recrystallization temperature up in the high temperature, and it became a creep test in the un-recrystallization condition, and the creep property of high temperature over 700 oC was drastically improved. The minimum creep rates of Fe-Ni alloys at 700 oC are found to be much lower than those of the conventional high Cr ferritic heat resistant steels, which is due to fine dispersion strengthening useful even at 700 oC in these alloys. As a result it became clear that the value for 100,000 h was exceeded at 700 oC and 100 MPa calculated from the Larson-Miller parameter at C = 20.

  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. 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

  20. [Reactive oxygen forms and Ca ions as possible intermediaries under the induction of heat resistance of plant cells by jasmonic acid].

    Science.gov (United States)

    Karpets, Iu V; Kolupaev, Iu E; Iastreb, T O; Obozny?, A I; Shvidenko, N V; Lugovaia, A A; Va?ner, A A

    2013-01-01

    The participation of reactive oxygen species (ROS) and calcium ions in realization of influence of exogenous jasmonic acid (JA) on the heat resistance of wheat coleoptiles has been investigated. Influence of 1 microM JA caused the transitional intensifying of generation of superoxide anion-radical (O2*-) and hydrogen peroxide in coleoptiles with the maximum within 15-30 minutes after the treatment beginning. Within the first hour after the beginning of coleoptiles treatment with JA the increase of superoxide dismutase (SOD) activity was noted. Later on (within 5-24 hours after the treatment beginning) there was the lowering of ROS generation by coleoptiles of experimental variant, and the SOD activity approached the control value. Intensifying of generation of superoxide radical induced by JA was suppressed by the antioxidant ionol and was partially levelled by imidazole (inhibitor of NADPH-oxidase), EGTA (chelator of extracellular calcium) and lanthanum chloride (calcium channels blocker). Pretreatment of coleoptiles with the ionol, imidazole, EGTA and LaC3l3 also partially removed the effect of increase of their resistance to the damaging heating caused by exogenous JA. It is supposed that the ROS generated with participation NADPH-oxidase, which activity depends on the receipt of calcium ions from extracellular space in the cytosol, are involved in realization of physiological effects of JA. PMID:23937049

  1. An irradiation test of heat-resistant ceramic composite materials. Interim report on post-irradiation examinations of the first preliminary irradiation test: 97M-13A

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Shin-ichi; Takahashi, Tsuneo; Ishihara, Masahiro; Hayashi, Kimio; Sozawa, Shizuo; Saito, Takashi [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Suzuki, Yoshio [Nuclear Engineering, Co. Ltd., Osaka (Japan); Saito, Tamotsu; Sekino, Hajime [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    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 first capsule, designated 97M-13A, to fast neutron fluences of 1.2-1.8x10{sup 24} m{sup -2} (E>1 MeV) at temperatures of 573, 673 and 843 K. In the PIE, measurements were made on (1) dimensional changes, (2) thermal expansions, (3) X-ray parameters and (4) {gamma}-ray spectra. The results for the carbon/carbon and SiC/SiC composites were similar to those in existing literatures. The temperature monitor effect was observed both for SiC fiber- and particle-reinforced SiC composites as in the case of monolithic SiC. Namely, the curve of the coefficient of thermal expansion (CTE) of these specimens showed a rapid drop above a temperature around the irradiation temperature +100 K in the first ramp (ramp rate: 10 K/min), while in the second ramp the CTE curves were almost the same as those of un-irradiated SiC specimens. (author)

  2. 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.)

  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. Heat-resistant and rigid-flexible coupling glass-fiber nonwoven supported polymer electrolyte for high-performance lithium ion batteries

    International Nuclear Information System (INIS)

    A heat-resistant and rigid-flexible coupling glass-microfiber nonwoven supported cyanoethyl-β-polyvinyl alcohol composite polymer electrolyte membrane (GFMPE) has been successfully fabricated explored for high-performance lithium batteries. It was demonstrated that the GFMPE possessed enhanced mechanical property, superior dimensional thermostability (>200 °C). In addition, Ethylene carbonate (EC)/Dimethyl carbonate (DMC) solvent soaked GFMPE exhibited a superior Li ion transport number of 0.86, wide electrochemical window up to 4.8 V vs Li+/Li and high ionic conductivity of 0.89 mS/cm at 25 °C. Moreover, LiCoO2/graphite cells using such polymer electrolyte with EC:DMC (1:1, v/v) showed excellent cycling stability and superior rate capability at room temperature. It is important to note that the LiFePO4/Li cell using GFMPE/propylene carbonate (PC) can also operate very well at an elevated temperature of 120 °C. These fascinating results would endow GFMPE a very promising polymer electrolyte in high-performance lithium batteries with improved safety and reliablity

  6. 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.

  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. Fire and heat resistant laminating resin based on maleimido and citraconimido substituted 1-(diorganooxyphosphonyl-methyl)-2,4- and -2,6-diaminobenzenes

    Science.gov (United States)

    Beggs, James M. (inventor); Mikroyannidis, John A. (inventor); Kourtides, Demetrius A. (inventor)

    1988-01-01

    The subject invention pertains to a novel class of fire-and heat-resistant bisimide resins prepared by thermal polymerization of maleimido or citraconimido substituded 1-(dialkoxyphosphonyl)-methyl-2-4 and -2,6-diaminobenzenes. Typical polymer presursors have the chemical structure wherein R is alkyl, substituted alkyl or aryl, and R sup 1 is hydrogen or lower alkyl. The polymer precursors are prepared by reacting 1-(diorganooxyphosphonyl)methyl-2-4 and -2,6-diaminobenzenes with maleic anhydride or citraconic anhydride in a mole ratio 1:2. Chains extension of the monomers is achieved by reacting the mono-N-maleimido derivatives of 1-(diorganooxyphosphonyl)methyl-2,4 and -2,6-diaminobenzenes with aryl tetracarboxylic dianhydrides, such as benzophenone tetracarboxylic diandydride, or aryl diisocyanates, such as methylenebis (4-phenylisocyanate), in a mole ratio 2:1. The polymerization of the monomers is studied by differential scanning calorimetry (DSC) and the thermal stability of the polymers is ascertained by thermogravimetric analysis (TGA).

  9. 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.)

  10. Heat resistance of Byssochlamys ascospores.

    Science.gov (United States)

    Bayne, H G; Michener, H D

    1979-03-01

    Ascospores from 25 strains of Byssochlamys were studied for their ability to resist heat treatment in a standard defined medium. Seven of these were able to survive heating at 90 degrees C for 25 min or longer, when initial numbers were frequently near 10(6)/ml. Ascospores from five resistant strains suspended in the medium at pH 5.0 were usually more resistant than those at pH 3.6. Rapid heat inactivation occurred for one strain at pH 6.6. Nonlogarithmic heat death rate was observed in all strains tested. PMID:36842

  11. 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)

  12. Silicon Alloying On Aluminium Based Alloy Surface

    International Nuclear Information System (INIS)

    Silicon alloying on surface of aluminium based alloy was carried out using electron beam. This is performed in order to enhance tribological properties of the alloy. Silicon is considered most important alloying element in aluminium alloy, particularly for tribological components. Prior to silicon alloying. aluminium substrate were painted with binder and silicon powder and dried in a furnace. Silicon alloying were carried out in a vacuum chamber. The Silicon alloyed materials were assessed using some techniques. The results show that silicon alloying formed a composite metal-non metal system in which silicon particles are dispersed in the alloyed layer. Silicon content in the alloyed layer is about 40% while in other place is only 10.5 %. The hardness of layer changes significantly. The wear properties of the alloying alloys increase. Silicon surface alloying also reduced the coefficient of friction for sliding against a hardened steel counter face, which could otherwise be higher because of the strong adhesion of aluminium to steel. The hardness of the silicon surface alloyed material dropped when it underwent a heating cycle similar to the ion coating process. Hence, silicon alloying is not a suitable choice for use as an intermediate layer for duplex treatment

  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. Inactivation of chemical and heat-resistant spores of Bacillus and Geobacillus by nitrogen cold atmospheric plasma evokes distinct changes in morphology and integrity of spores.

    Science.gov (United States)

    van Bokhorst-van de Veen, Hermien; Xie, Houyu; Esveld, Erik; Abee, Tjakko; Mastwijk, Hennie; Nierop Groot, Masja

    2015-02-01

    Bacterial spores are resistant to severe conditions and form a challenge to eradicate from food or food packaging material. Cold atmospheric plasma (CAP) treatment is receiving more attention as potential sterilization method at relatively mild conditions but the exact mechanism of inactivation is still not fully understood. In this study, the biocidal effect by nitrogen CAP was determined for chemical (hypochlorite and hydrogen peroxide), physical (UV) and heat-resistant spores. The three different sporeformers used are Bacillus cereus a food-borne pathogen, and Bacillus atrophaeus and Geobacillus stearothermophilus that are used as biological indicators for validation of chemical sterilization and thermal processes, respectively. The different spores showed variation in their degree of inactivation by applied heat, hypochlorite, hydrogen peroxide, and UV treatments, whereas similar inactivation results were obtained with the different spores treated with nitrogen CAP. G. stearothermophilus spores displayed high resistance to heat, hypochlorite, hydrogen peroxide, while for UV treatment B. atrophaeus spores are most tolerant. Scanning electron microscopy analysis revealed distinct morphological changes for nitrogen CAP-treated B. cereus spores including etching effects and the appearance of rough spore surfaces, whereas morphology of spores treated with heat or disinfectants showed no such changes. Moreover, microscopy analysis revealed CAP-exposed B. cereus spores to turn phase grey conceivably because of water influx indicating damage of the spores, a phenomenon that was not observed for non-treated spores. In addition, data are supplied that exclude UV radiation as determinant of antimicrobial activity of nitrogen CAP. Overall, this study shows that nitrogen CAP treatment has a biocidal effect on selected Bacillus and Geobacillus spores associated with alterations in spore surface morphology and loss of spore integrity. PMID:25481059

  15. 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

  16. 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).

  17. MATE (Materials for Advanced Turbine Engines) Program, Project 3. Volume 2: Design, fabrication and evaluation of an oxide dispersion strengthened sheet alloy combustor liner

    Science.gov (United States)

    Bose, S.; Sheffler, K. D.

    1988-01-01

    The suitability of wrought oxide dispersion strengthened (ODS) superalloy sheet for gas turbine engine combustor applications was evaluated. Two yttria (Y2O3) dispersion strengthened alloys were evaluated; Incoloy MA956 and Haynes Development Alloy (HDA) 8077 (NiCrAl base). Preliminary tests showed both alloys to be potentially viable combustor materials, with neither alloy exhibiting a significant advantage over the other. MA956 was selected as the final alloy based on manufacturing reproducibility for evaluation as a burner liner. A hybrid PW2037 inner burner liner containing MA956 and Hastelloy X components and using a louvered configuration was designed and constructed. The louvered configuration was chosen because of field experience and compatibility with the bill of material PW2037 design. The simulated flight cycle for the ground based engine tests consisted of 4.5 min idle, 1.5 min takeoff and intermediate conditions in a PW2037 engine with average uncorrected combustor exit temperature of 1527 C. Post test evaluation consisting of visual observations and fluorescent penetrant inspections was conducted after 500 cycles of testing. No loss of integrity in the burner liner was shown.

  18. 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

  19. On the problem of creation of structural materials on the basis of hard alloys

    International Nuclear Information System (INIS)

    Chemical composition and structure of refractory skeletons produced by the methods of self-propagating high temperature synthesis (SHS) and powder metallurgy were studied for their effects on high temperature mechanical properties hard alloys on these skeletons base. Porous skeletons were obtained on the base of TiC0.55; TiC0.65; TiC0.75; TiC0.85 and TiC1.0 carbides with their subsequent impregnation with heat resisting nickel base alloy ZhS6U. It was shown that a sintered skeleton was prone to fracture while SHS-skeleton preserved its structure. Optimal operating temperature of materials considered was noted to depend on the temperatures of brittle-ductile transition and transition into superplastic stable of refractory phase

  20. 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

    Directory of Open Access Journals (Sweden)

    Beatriz de Cássia Martins Salomão

    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 termorresistente. 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.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.

  1. Heat-Resistant Ferritic-Martensitic Steel RUSFER-EK-181 (Fe-12Cr-2W-V-Ta-B) for Fusion Power Reactor

    International Nuclear Information System (INIS)

    Full text: The study of initial (unirradiated) functional properties of Russian RAFMS RUSFER-EK-181 (Fe-12Cr-2W-V-Ta-B) as advanced heat-and radiation-resistant structural material for fusion power reactors has been continued. RUSFER-EK-181 steel is related to precipitation hardening (nanostructured) materials type. The regularities of low temperature brittle fracture (crack growth resistance) of the steel at static and dynamic concentrated loads depending on the sizes of Charpy V-Noch (CVN) specimens, type of stress concentrators (V-notches or a fatigue crack) were investigated in the temperature range from -196 deg. C to +100 deg. C. Fracture toughness tests estimating KIC and JIC (static concentrated bending) were conducted. The ductile-to-brittle transition temperatures (DBTT) were determined in the range from -85 deg. C to +35 deg. C depending on the type of CVN-specimens and stress states (fatigue crack, central and side V-notches). The work of low temperature fracture of the steel depends on the type of the stress concentrators and specimen sizes and is governed by the elastic energy store and the conditions of plastic deformation in the near-surface layers of the specimens regulated by side notches. The marked level of permanent deformation and impact toughness (not less than 3 - 5 J/cm2) was observed at low temperatures (lower than DBTT). Short-term (yield strength, ultimate strength, elongation to rupture) and long-term (creep, diagram 'stress vs time to rupture') properties, temperature conductivity, thermal conductivity and linear expansion of the steel were investigated in the temperature range to 750oC. Diffusion characteristics of self-point defects (vacancies and interstitial atoms) in iron crystal with dislocations of different types were calculated by the methods of multiscale modeling in the temperature range from room temperature to 1000K. Nuclear transmutation changes of the chemical composition and the structure and phase state (Schaeffler diagram) of the steel were calculated for the long-term irradiation in neutron spectrum of the fusion reactor DEMO-RF. Obtained data for functional properties of the RAFMS RUSFER-EK-181 characterize it as the nanostructured structural steel with a good heat resistant (up to 700oC), good resistance to low temperature embrittlement, sufficient radiation resistance of the chemical composition and the structure and phase state. (author)

  2. Influence of content of lanthanum, cerium and rhenium in filler material on properties of heat-resisting metal built-up by argon arc process

    International Nuclear Information System (INIS)

    Mechanical behaviour and resistance to hot cracking have been studied of a refractory metal welded joints deposited by argon arc welding. The nickel-chrome based metal was alloyed by lanthanum, cerium and rhenium. At La and Ce concentrations above 0.1% the strength and plasticity of the welded metal sharply decrease at 20 deg and 800 deg C due to grain boundary embrittlement on account of a second phase formation. As the Re content grows to 6%, the strength and plasticity increase as the solid solution is strengthened. It is recommended to limit La and Ce content in the additives by 0.1% or to additionally alloy them by 1.5. Re

  3. Substitution of Nickel by Combined Addition of Cobalt and Zirconium in Alloy A 332

    Science.gov (United States)

    Wüstenhagen, Andreas; Tonn, Babette

    2011-01-01

    Due to the increasing international competition and the resulting pricing pressure it is imperative to avoid the use of expensive alloying elements during the production of aluminium castings. The piston alloy A 332 shows an optimum combination of mechanical and casting properties and an attractive cost-performance ratio whereas nickel is the most expensive alloying element. A substitution of nickel by a combined addition of low contents of cobalt and zirconium has the potential capacitiy to increase the mechanical properties and reduce the costs of the alloy. At Clausthal University of Technology Thermo-Calc simulations and casting experiments were carried out to investigate the effect of the nickel subtitution. Thermo-Calc-simulations were made to analyze the intermetallic phases in these alloys. These simulations were evaluated by observations under optical microscope and SEM of specimens poured into permanent moulds. The size and morphology of the intermetallic phases and the primary silicon was analyzed by the use of image analysis software. The mechanical properties of the alloys were determined by tensile tests at room temperature, 250° C and 350° C. The tensile specimens were tested in as-cast and pre-aged condition. The effect on the castability was characterized by determining the flow length and the susceptibility to form shrinkages and hot cracks. The standard alloy A 332 and the new piston alloy with cobalt and zirconium were compared. The new alloy AlSi12,6Cu1Mg1CoZr exhibits a yield strength of 115 MPa and a tensile strength of 171 MPa at 250° C in pre-aged condition (250° C/100 h). At 350° C the new alloy displays a yield strength of 57 MPa and a tensile strength of 85 MPa in pre-aged condition (350° C/100h). Compared to the reference alloy AlSi12,6Cu1Ni1Mg1 the yield strength at 250° C was improved about 25% and the yield strength at 350° C about 7%. The favorable castability of the reference alloy is not affected by the substitution of nickel. These results prove the development of a heat-resistant, thermally stable alloy without nickel. The mechanical properties and the cost-performance ratio are superior to the standard alloy. The competitiveness of the new piston alloy was improved significantly.

  4. Corrosion screening tests with Ni-base alloys in supercritical water containing hydrochloric acid and oxygen

    International Nuclear Information System (INIS)

    Corrosion of reactor material during oxidation of hazardous organic waste containing chloride proceeds very fast and constitutes one major problem in SCWO applications. The following Ni-base alloys were tested within the framework of the experimental program: Inconel 625 and 686, Hastelloy C-276, Nicrofer 5923 and 6025, and Haynes alloy 214. Test tubes were fabricated from these materials and exposed to SCWO conditions, without organics, at temperatures up to 600 C and pressures up to 34 MPa. Higher concentrated HCl solutions or the combination of oxygen and HCl cause strong surface destruction. The corrosion measured was higher at lower temperatures and at higher pressures, if all other conditions remained constant. The most severe corrosion--general corrosion with SCC and pitting--appeared at temperatures near the critical temperature, i.e., in the preheater and cooling sections of the test tubes. The corrosion products were insoluble in supercritical water and formed thick layers in the supercritical part of the reactor. Under these layers only minor corrosion occurred

  5. Study of cutting speed on surface roughness and chip formation when machining nickel-based alloy

    International Nuclear Information System (INIS)

    Nickel- based alloy is difficult-to-machine because of its low thermal diffusive property and high strength at higher temperature. The machinability of nickel- based Hastelloy C-276 in turning operations has been carried out using different types of inserts under dry conditions on a computer numerical control (CNC) turning machine at different stages of cutting speed. The effects of cutting speed on surface roughness have been investigated. This study explores the types of wear caused by the effect of cutting speed on coated and uncoated carbide inserts. In addition, the effect of burr formation is investigated. The chip burr is found to have different shapes at lower speeds. Triangles and squares have been noticed for both coated and uncoated tips as well. The conclusion from this study is that the transition from thick continuous chip to wider discontinuous chip is caused by different types of inserts. The chip burr has a significant effect on tool damage starting in the line of depth-of-cut. For the coated insert tips, the burr disappears when the speed increases to above 150 m/min with the improvement of surface roughness; increasing the speed above the same limit for uncoated insert tips increases the chip burr size. The results of this study showed that the surface finish of nickel-based alloy is highly affected by the insert type with respect to cutting speed changes and its effect on chip burr formation and tool failure

  6. 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

  7. Effect of Pr addition on microstructure and mechanical properties of AZ61 magnesium alloy

    Directory of Open Access Journals (Sweden)

    You Zhiyong

    2014-03-01

    Full Text Available To improve the strength, hardness and heat resistance of Mg-6Al-1Zn (AZ61 alloy, the effects of Pr addition on the as-cast microstructure and mechanical properties of AZ61 alloy were investigated at room and elevated temperatures by means of Brinell hardness measurement, optical microscope (OM, scanning electron microscope (SEM, energy dispersive spectroscopy (EDS, X-ray diffractometer (XRD and DNS100 electronic universal testing machine. The results show that the microstructures of Pr-containing AZ61 alloys were refined, with primary ?-Mg17Al12 phase distributed homogeneously. When the addition of Pr is up to 1.2wt.%, the ? phase becomes finer, and new needle-like or short-rod shaped Al11Pr3 phase and blocky AlPr phase appear. As a result, optimal tensile properties are obtained. However, greater than 1.2wt.% Pr addition leads to poorer mechanical properties due to the aggregation of the needle-like phase and large size of grains. The present research findings provide a new way for strengthening of magnesium alloys at room and elevated temperatures, and a method of producing thermally-stable AZ61 magnesium alloy.

  8. 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

  9. 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

  10. Mechanical properties of pure Ni and Ni-alloy substrate materials for Y Ba Cu O coated superconductors

    Science.gov (United States)

    Clickner, C. C.; Ekin, J. W.; Cheggour, N.; Thieme, C. L. H.; Qiao, Y.; Xie, Y.-Y.; Goyal, A.

    2006-06-01

    Mechanical properties of rolling-assisted, biaxially-textured substrates (RABiTS) and substrates for ion-beam assisted deposition (IBAD) coated superconductors are measured at room temperature, 76, and 4 K. Yield strength, Young's modulus, and the proportional limit of elasticity are determined, tabulated and compared. Results obtained are intended to serve as a database of mechanical properties of substrates having the same anneal state and texture as those incorporated in the general class of RE-Ba-Cu-O coated conductor composites (RE = rare earth). The RABiTS materials measured are pure Ni, Ni-13at.%Cr, Ni-3at.%W-2at.%Fe, Ni-10at.%Cr-2at.%W, and Ni-5at.%W. The IBAD substrate materials included Inconel 625 and Hastelloy C-276. The Ni alloys are substantially stronger and show higher strains at the proportional limit than those of pure Ni. Substrates fully coated with buffer layers, ?1 ?m of Y-Ba-Cu-O, and 3-5 ?m of Ag have similar mechanical properties (at 76 K) as the substrate alone. Somewhat surprisingly, plating an additional 30-40 ?m of Cu stabilizer onto high-yield-strength (690 MPa) Hastelloy coated conductors ˜100 ?m thick, reduces the overall yield strength of the composite structure by only about 10-12% at 76 K and 12-14% at room temperature; this indicates that the Cu layer, despite its relatively soft nature, contributes significantly to the overall strength of even high-strength coated conductors.

  11. 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)

  12. 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

  13. 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

  14. Promising technologies for the surface treatment at production and repair of Ti alloys vanes of gas turbine engines with the help of power ion and electron beams

    International Nuclear Information System (INIS)

    By means of AES, SEM, TEM, X-ray diffraction, exoelectron emission as well as by optical metallography in polarized light physical and chemical properties of the surface layers of heat-resistant Ti-based alloys (VT6, VT8, VT9) for application in aviation gas turbine engines exposed to power pulsed ion and electron beams have been investigated. A comparative fatigue tests as well as corrosion and erosion ones of initial serial and irradiated turbine blades were carried out. Perspective fields for the pulsed ion and electron beams application are chosen

  15. 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.

  16. 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.)

  17. 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.

  18. Tantalum-niobium alloys

    International Nuclear Information System (INIS)

    Presented is the review of physical, chemical, mechanical and technological properties of tantalum-niobium alloys which form a contineous series of solid solutions. The above alloys used in the production of various devices operating in reactive media. Results of investigations of Ta-Nb alloys of various compositions using mono and polycrystal samples at the temperatures from -195 to 1800 deg C are summarized. Prospects for tantalum substitution for Ta-Nb alloys due to reduction of the consumption of expensive tantalum and usability of unseparated mixture of tantalum-niobium oxides as raw mateirals for alloy fabrication are noted. Methods of fabrication and working of Ta-Nb alloys are described

  19. 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)

  20. Ferroelectric and ferromagnetic properties of epitaxial BiFeO3-BiMnO3 films on ion-beam-assisted deposited TiN buffered flexible Hastelloy

    International Nuclear Information System (INIS)

    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 (BiFeO3)0.5:(BiMnO3)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 La0.7Sr0.3MnO3 (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/cm2. The magnetization of the BFO-BMO/LSMO is 62?emu/cc at room temperature

  1. Turbine Blade Alloy

    Science.gov (United States)

    MacKay, Rebecca

    2001-01-01

    The High Speed Research Airfoil Alloy Program developed a fourth-generation alloy with up to an +85 F increase in creep rupture capability over current production airfoil alloys. Since improved strength is typically obtained when the limits of microstructural stability are exceeded slightly, it is not surprising that this alloy has a tendency to exhibit microstructural instabilities after high temperature exposures. This presentation will discuss recent results obtained on coated fourth-generation alloys for subsonic turbine blade applications under the NASA Ultra-Efficient Engine Technology (UEET) Program. Progress made in reducing microstructural instabilities in these alloys will be presented. In addition, plans will be presented for advanced alloy development and for computational modeling, which will aid future alloy development efforts.

  2. 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.

  3. Fundamental considerations for the development of oxidation-resistant alloys and coatings based on ?-TiAl

    Science.gov (United States)

    Singheiser, L.; Niewolak, L.; Shemet, V.; Quadakkers, W. J.; Flesch, U.

    2003-10-01

    Alloys based on ?-TiAl are promising high-temperature materials that may replace conventional heat-resistant steels and superalloys in applications where high strength in combination with low density is required. However, an important hindrance to the use of ?-TiAl alloys at high temperatures is their relatively poor oxidation resistance and sensitivity against environmentally induced embrittlement. This material degradation is related to the poor protective properties of the mixed TiO2/Al2O3 surface scales which form on the surface during high-temperature exposure. Recently, it was shown that protective alumina scale formation on ?-TiAl can be obtained by small additions of Ag. This effect was found to be related to the formation of Z phase in the subscale depletion layer at the expense of ? 2-Ti3Al. It was found that the beneficial effect of Ag can be suppressed if the alloys contain additional ? 2-stabilizing elements, such as Nb, as is the case for most (semi)commercial, high-strength alloys. Therefore, recent efforts have concentrated on developing Ag-containing ?-TiAl alloys as oxidation-resistant coatings for high-strength titanium aluminides. Preliminary results using magnetron sputtering have shown that, due to the similarities in chemical and physical properties of the coating and base material, the Ag-containing material offers promising potential to be qualified as a coating material for reducing the oxidation-induced degradation of titanium aluminides.

  4. 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

  5. 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)

  6. High frequency fatigue test of IN 718 alloy – microstructure and fractography evaluation

    Directory of Open Access Journals (Sweden)

    J. Belan

    2015-01-01

    Full Text Available INCONEL alloy 718 is a high-strength, corrosion-resistant nickel chromium material used at -253 °C to 705 °C for production of heat resistant parts of aero jet engine mostly. The fatigue test provided on this kind materials were done via low frequency loading up to this time. Nowadays, needs of results at higher volume of loading cycles leads to high frequency loading with aim to shorten testing time. Fatigue test of experimental material was carried out at frequency 20 kHz with stress ration R = - 1 (push – pull at room temperature. It was found that this superalloy can still fracture after exceeding 108 cycles. Besides fatigue test were microstructural characterisation and scanning electron microscopy (SEM fractography evaluation done.

  7. 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.

  8. 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.

  9. 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.

  10. Oxidation of CoCrFeMnNi High Entropy Alloys

    Science.gov (United States)

    Holcomb, Gordon R.; Tylczak, Joseph; Carney, Casey

    2015-06-01

    Eight model high entropy alloys (HEAs) in the CoCrFeMnNi family (including one alloy each in the CoCrFeNi and CoFeMnNi subfamilies) were made, prepared, and exposed to laboratory air for 1100 h at 650°C and 750°C. Two commercial alloys, nickel-base superalloy 230 (N06230) and austenitic stainless steel 304H (S30409), were simultaneously exposed for comparison. Mass change oxidation kinetics were measured and cross-sections of exposed samples were observed. Seven of these HEAs contained much more Mn (12-24 wt.%) than is found in commercial heat-resistant stainless steels and superalloys. The oxidation resistance of CoCrFeNi was excellent and comparable to 304H at 650°C and only slightly worse at 750°C. The thin oxide scale on CoCrFeNi was primarily Cr oxide (presumably Cr2O3) with some Mn oxide at the outer part of the scale. The CoCrFeMnNi HEAs all experienced more rapid oxidation than CoCrFeNi and, especially at 750°C, experienced oxide scale spallation. The addition of Y in the alloy to lower S improved the oxidation resistance of these HEAs. Alloy CoFeMnNi, without Cr, experienced much higher oxidation rates and scale spallation than the Cr-containing alloys. A linear regression analysis of the log of the parabolic rate constant, log(kp), as functions of wt.% Cr and Mn found a good correlation for the compositional dependence of the oxidation rate constant, especially at 650°C. Mn was found to be more detrimental increasing log(k p) than Cr was helpful reducing log(k p). If CoCrFeMnNi HEAs are to be used in high temperature oxidizing environments, then examining lower levels of Mn, while maintaining Cr levels, should be pursued.

  11. Spark alloying of an AL9 alloy by hard alloys

    Science.gov (United States)

    Kuptsov, S. G.; Fominykh, M. V.; Mukhinov, D. V.; Magomedova, R. S.; Nikonenko, E. A.

    2015-08-01

    The phase compositions of spark coatings of Kh12M steel with a VT1-0 (titanium) alloy and T15K6 and T30K4 hard alloys are studied. It is shown that the TiC titanium carbide forms in all cases and tungsten carbide decomposes with the formation of tungsten in a coating. These processes are intensified by increasing time, capacitance, and frequency. The surface hardness, the sample weight, and the white layer thickness increase monotonically.

  12. Creep Resistant Zinc Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Frank E. Goodwin

    2002-12-31

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

  13. A study of kinetics of formation, structure, composition, and properties of electrospark coatings of modified electrode materials on the basis of TiC-KhN70Yu applied on OT4-1 titanium alloy

    International Nuclear Information System (INIS)

    The effect of nanodispersed additives (ZrO2, Al2O3, W, WC, WC-Co, NbC, Si2N4) on mass transfer of SHS-electrode materials on the basis of TiC-KhN70Yu was studied. A complex of investigations of electrospark coatings on OT4-1 alloy was carried out. An optimum mode of application of ESA-coatings was found using new modified electrode materials in the HF-plant. It was established that introduction of nanodispersed component into the electrode material promotes increasing mass transfer, thickness growth, uniformity, microhardness, and heat resistance of ESA-coatings

  14. Catalyst Alloys Processing

    Science.gov (United States)

    Tan, Xincai

    2014-10-01

    Catalysts are one of the key materials used for diamond formation at high pressures. Several such catalyst products have been developed and applied in China and around the world. The catalyst alloy most widely used in China is Ni70Mn25Co5 developed at Changsha Research Institute of Mining and Metallurgy. In this article, detailed techniques for manufacturing such a typical catalyst alloy will be reviewed. The characteristics of the alloy will be described. Detailed processing of the alloy will be presented, including remelting and casting, hot rolling, annealing, surface treatment, cold rolling, blanking, finishing, packaging, and waste treatment. An example use of the catalyst alloy will also be given. Industrial experience shows that for the catalyst alloy products, a vacuum induction remelt furnace can be used for remelting, a metal mold can be used for casting, hot and cold rolling can be used for forming, and acid pickling can be used for metal surface cleaning.

  15. 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...

  16. Effect of Cu addition on microstructure and properties of Mg-10Zn-5Al-0.1Sb high zinc magnesium alloy

    Directory of Open Access Journals (Sweden)

    You Zhiyong

    2012-02-01

    Full Text Available To improve the strength, hardness and heat resistance of Mg-Zn based alloys, the effects of Cu addition on the as-cast microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb high zinc magnesium alloy were investigated by means of Brinell hardness measurement, scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS, XRD and tensile tests at room and elevated temperatures. The results show that the microstructure of as-cast Mg-10Zn-5Al-0.1Sb alloy is composed of ?-Mg, t-Mg32(Al, Zn49, ?-Al2Mg5Zn2 and Mg3Sb2 phases. The morphologies of these phases in the Cu-containing alloys change from semi-continuous long strip to black herringbone as well as particle-like shapes with increasing Cu content. When the addition of Cu is over 1.0wt.%, the formation of a new thermally-stable Mg2Cu phase can be observed. The Brinell hardness, room temperature and elevated temperature strengths firstly increase and then decrease as the Cu content increases. Among the Cu-containing alloys, the alloy with the addition of 2.0wt.% Cu exhibits the optimum mechanical properties. Its hardness and strengths at room and elevated temperatures are 79.35 HB, 190 MPa and 160 MPa, which are increased by 9.65%, 21.1% and 14.3%, respectively compared with those of the Cu-free one. After T6 heat treatment, the strengths at room and elevated temperatures are improved by 20% and 10%, respectively compared with those of the as-cast alloy. This research results provide a new way for strengthening of magnesium alloys at room and elevated temperatures, and a method of producing thermally-stable Mg-10Zn-5Al based high zinc magnesium alloys.

  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. Copper-tantalum alloy

    Science.gov (United States)

    Schmidt, Frederick A. (Ames, IA); Verhoeven, John D. (Ames, IA); Gibson, Edwin D. (Ames, IA)

    1986-07-15

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

  20. Neutron-absorbing alloy

    International Nuclear Information System (INIS)

    The composition of the proposed neutron absorbing alloy varies within the following limits: 1-20 wt.-% In, 0,5-15 wt.-% Sm, 5-18 wt.-% Hf, 47-93,5 wt.-% Ni. Three examples are given with characteristic values. The alloy is to be used in automatic control and emergency protection systems of nuclear reactors. (UW/LH)

  1. Aluminum battery alloys

    Science.gov (United States)

    Thompson, David S. (Richmond, VA); Scott, Darwin H. (Mechanicsville, VA)

    1985-01-01

    Aluminum alloys suitable for use as anode structures in electrochemical cs are disclosed. These alloys include iron levels higher than previously felt possible, due to the presence of controlled amounts of manganese, with possible additions of magnesium and controlled amounts of gallium.

  2. Thermofluency in zirconium alloys

    International Nuclear Information System (INIS)

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

  3. 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.

  4. 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.

  5. Alloys in energy development

    International Nuclear Information System (INIS)

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

  6. Magnetostrictive nickel base alloys

    International Nuclear Information System (INIS)

    The ways of optimization of magnetostrictive alloys on the Ni-4%Co base are under consideration. A number of binary and ternary alloys of the Ni-Co-Mn system were prepared with variations of Co and Mn contents in the range of 0-6% at intervals of 2%. Measurements of magnetic anisotropy and magnetostriction were carried out on the ribbons produced by hot and cold rolling and then annealed. On the basis of data obtained three new alloys for electroacoustic applications are proposed: Ni-3.5%Co-1%Mn; Ni-3.25%Co-3%W; a cobalt-free alloy NMGT. THe alloys proposed have acoustic properties comparable with those of conventional materials and surpass the latter in strength and corrosion resistance. 10 refs., 2 figs., 1 tab

  7. 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

  8. 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.

  9. Brazing with plated alloys

    International Nuclear Information System (INIS)

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

  10. 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!!!

  11. 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!!!

  12. 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.)

  13. 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)

  14. UV Curable Heat Resistant Epoxy Acrylate Coatings

    OpenAIRE

    Firdous, Habib; Bajpai, Madhu

    2010-01-01

    ? ?????? ??????? ????????? ?????- ?????????? ??-???????????? ?????????, ???????? ? ???????- ????????? ?? ?????-?????????? ????, ? ??????????? ?????? ?? ???????? ??????????? ????????????????. ???????????, ?????? ???????? ???????????????? ??????? ????????????????? (693 ?) ?? ?????????? ??????? ? ??????? ?????????. ?????????????? ????? ??? ?????????? ?????????? ??????????? ????????, ???????? ?? ?? ???????????, ??? ? ????????????? ????????, ? ???? ????? ??????? ??? ???????...

  15. Heat resistance of fungi from soil.

    Science.gov (United States)

    Jesenská, Z; Piecková, E; Bernát, D

    1993-08-01

    The survival of fungi from soil samples has been investigated after exposure to temperatures of 60, 70, 80 and 90 degrees C in Sabouraud agar. The least resistant fungi surviving 60 degrees C for 60 min were the Aspergillus (A.) niger group, Chaetomium spp, Penicillium spp, and Scytalidium lignicola. None of these survived 70 degrees C for 10 min. The next group surviving 70 degrees C for 60 min included the A. glaucus group, Byssochlamys nivea, Dichotomomyces cejpii, Gelasinospora spp, Rhizoctonium spp, and Talaromyces flavus; they did not survive 80 degrees C for 10 min. At 80 degrees C for 60 min, survival was seen for Aspergillus fumigatus, Aspergillus nidulans, Eupenicillium baarnense and Ulocladium spp; they did not survive 10 min at 90 degrees C. Acremonium sclerotigenum, Aspergillus ochraceus, Botryotrichum piluliferum, Byssochlamys fulva, Gilmaniella humicola, Neosartorya fischeri, Nodulisporium sp. and Talaromyces avellaneus survived heat treatment at 90 degrees C for 10 min and longer time with the two last being the most resistant. The phenomen of activation of dormant spores by thermal shock was not apparent. PMID:8217516

  16. Heat resistant polymers of oxidized styrylphosphine

    Science.gov (United States)

    Paciorek, K. J. L. (inventor)

    1978-01-01

    Homopolymers, copolymers and terpolymers of a styrene based monomer are prepared by polymerizing at least one oxidized styrylphosphine monomer or by polymerizing p-diphenylphosphinestyrene and then oxidizing the polymerized monomer with an organoazide. Copolymers can also be prepared by copolymerizing styrene with at least one oxidized styrylphosphine monomer. Flame resistant vinyl based polymers whose degradation products are non toxic and non corrosive are obtained.

  17. Fire- and Heat-Resistant Laminating Resins

    Science.gov (United States)

    Kourtides, Demetrius A.; Mikroyannidis, John A.

    1987-01-01

    Imide compounds containing phosphourus thermally polymerized. New maleimido- or citraconimido-end-capped monomers, have relatively low melting temperatures, polymerized at moderate temperatures to rigid bisimide resins without elimination of volatiles. Monomers dissolve in such solvents as methyl ethyl ketone, acetone, and tetrahydrofuran, suitable and perferred as "varnish solvents" for composite fabrication. Low melting points of these componds allow use as adhesives without addition of solvents.

  18. 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.

  19. 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.

  20. 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