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Sample records for refurbishing superalloy components

  1. Laser based refurbishment of steel mill components

    CSIR Research Space (South Africa)

    Kazadi, P

    2006-03-01

    Full Text Available Laser refurbishment capabilities were demonstrated and promising results were obtained for repair of distance sleeves, foot rolls, descaler cassette, idler rolls. Based on the cost projections and the results of the in-situ testing, components which...

  2. Refurbishment of Cirus in-core components

    International Nuclear Information System (INIS)

    Bhatnagar, A.; Sahu, A.K.; Rathore, K.K.; Subudhi, D.; Kharpate, A.V.; Tikku, A.C.

    2006-01-01

    Circus is a 40- MWt vertical tank type research reactor with natural uranium as fuel, demineralised light water as coolant, heavy water as moderator and graphite as reflector. The reactor was commissioned in the year 1960 and operated at an overage availability factor of over 70% till early nineties, when various systems, structures and components (SSCs) started showing signs of ageing. Detailed ageing studies were therefore carried out to assess the condition of various SSCs and refurbishing requirements were finalized towards extending the life of the reactor. In-core components, being non-replaceable generally, were critically examined to the extent possible. Detailed visual examination of a few reactor vessel (RV) tubes, made of aluminium, was carried out using micro video camera and in addition all the RV tubes were inspected using eddy current testing method. RV shell, also made of aluminium, was similarly visually inspected with micro video camera. To assess the effect of irradiation on the RV material, samples of similar tubes irradiated to comparable neutron fluence were tested. Towards assessment of fatigue life of RV expansion joint, made of aluminium, a finite element analysis using NISA computer code was performed. Theoretical assessment for stored Wigner energy in graphite reflector was carried out. Graphite block samples were also removed from the reactor and stored energy levels were measured to plan for any in-situ graphite annealing, if required. Visual inspection of approachable portions of steel and aluminium thermal shields was also carried out. These water-cooled thermal shields provided above and below the RV were hydro tested. The weld joint between coolant inlet pipe and top plate of upper aluminium shield showed minor leakage. A special metallic hollow plug was developed and remotely installed in the leaky pipe to isolate the leaky portion while maintaining the coolant flow in the pipe. Helium leak was found from flange joints located on

  3. Integration of remote refurbishment performed on ITER components

    Energy Technology Data Exchange (ETDEWEB)

    Dammann, A., E-mail: alexis.dammann@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Antola, L. [AMEC, 31 Parc du Golf, CS 90519, 13596 Aix en Provence (France); Beaudoin, V. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Dremel, C. [Westinghouse, Electrique France/Astare, 122 Avenue de Hambourg, 13008 Marseille (France); Evrard, D. [SOGETI High Tech, 180 Rue René Descartes, 13851 Aix en Provence (France); Friconneau, J.P. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Lemée, A. [SOGETI High Tech, 180 Rue René Descartes, 13851 Aix en Provence (France); Levesy, B.; Pitcher, C.S. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

    2015-10-15

    Highlights: • System engineering approach to consolidate requirements to modify the layout of the Hot Cell. • Illustration of the loop between requirement and design. • Verification process. - Abstract: Internal components of the ITER Tokamak are replaced and transferred to the Hot Cell by remote handling equipment. These components include port plugs, cryopumps, divertor cassettes, blanket modules, etc. They are brought to the refurbishment area of the ITER Hot Cell Building for cleaning and maintenance, using remote handling techniques. The ITER refurbishment area will be unique in the world, when considering combination of size, quantity of complex component to refurbish in presence of radiation, activated dust and tritium. The refurbishment process to integrate covers a number of workstations to perform specific remote operations fully covered by a mast on crane system. This paper describes the integration of the Refurbishment Area, explaining the functions, the methodology followed, some illustrations of trade-off and safety improvements.

  4. Refurbishment programs

    International Nuclear Information System (INIS)

    Irish, C.S.

    2004-01-01

    As nuclear plants age, equipment becomes obsolete, outdated or just simply unreliable. This puts a lot of emphasis on replacement of the subject equipment. This can be an expensive proposition for safety related equipment due to design changes, requalification charges and the cost of the new equipment, specifically when the original component is obsolete. The presentation will explain how comprehensive refurbishment programs on many different types of equipment can alleviate this situation. The refurbishment program is a systematic refurbishment of equipment to an as new condition by replacing all of the age sensitive components within the equipment. This is carried out on all of the same type of equipment in a scheduled program. For example the plant may to decide to refurbish all of their Lambda LME-24 power supplies, or all of their Bailey modules, or all of their Agastat DSC Series relays. Independent of the item the process is the same. Refurbish each piece of equipment to an as new condition by replacing all of the age sensitive equipment. The equipment is then returned to the client as safety related, existing qualification maintained and with a new service life/warranty. This is not a simple repair. It is a planned refurbishment to an as new condition of certain equipment types throughout the plant and then carried out from equipment piece to equipment piece. The refurbishment program may even include introducing new spares into the plant. This is normally performed by upgrading (dedicating for safety related use and refurbishing to an 'as new' condition) surplus equipment and using these equipment pieces in the rotation of the plant equipment to refurbish the entire population of a selected piece of equipment at the plant. This process can be performed on many equipment types including power supplies, circuit boards, modules, relays, motors, breakers, and many more. The refurbishment program greatly increases the reliability of the equipment without the

  5. Recent trends in repair and refurbishing of steam turbine components

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    be adequately addressed at various stages of its design and fabrication. ... lead to plant shutdown, loss in production and productivity, fire explosion, radiation or gas ..... component manufacturers, there is a growing necessity for in-house ...

  6. Optimising mechanical properties of hot forged nickel superalloy 625 components

    Science.gov (United States)

    Singo, Nthambe; Coles, John; Rosochowska, Malgorzata; Lalvani, Himanshu; Hernandez, Jose; Ion, William

    2018-05-01

    Hot forging and subsequent heat treatment were resulting in substandard mechanical properties of nickel superalloy, Alloy 625, components. The low strength was found to be due to inadequate deformation during forging, excessive grain growth and precipitation of carbides during subsequent heat treatment. Experimentation in a drop forging company and heat treatment facility led to the establishment of optimal parameters to minimise grain size and mitigate the adverse effects of carbide precipitation, leading to successful fulfilment of mechanical property specifications. This was achieved by reducing the number of operations, maximising the extent of deformation by changing the slug dimensions and its orientation in the die, and minimising the time of exposure to elevated temperatures in both the forging and subsequent heat treatment processes to avoid grain growth.

  7. Performance of nickel base superalloy components in gas turbines

    DEFF Research Database (Denmark)

    Dahl, Kristian Vinter

    2006-01-01

    The topic of this thesis is the microstructural behaviour of hot section components in the industrial gas turbine......The topic of this thesis is the microstructural behaviour of hot section components in the industrial gas turbine...

  8. Nondestructive Induced Residual Stress Assessment in Superalloy Turbine Engine Components Using Induced Positron Annihilation (IPA)

    International Nuclear Information System (INIS)

    Rideout, C. A.; Ritchie, S. J.; Denison, A.

    2007-01-01

    Induced Positron Analysis (IPA) has demonstrated the ability to nondestructively quantify shot peening/surface treatments and relaxation effects in single crystal superalloys, steels, titanium and aluminum with a single measurement as part of a National Science Foundation SBIR program and in projects with commercial companies. IPA measurement of surface treatment effects provides a demonstrated ability to quantitatively measure initial treatment effectiveness along with the effect of operationally induced changes over the life of the treated component. Use of IPA to nondestructively quantify surface and subsurface residual stresses in turbine engine materials and components will lead to improvements in current engineering designs and maintenance procedures

  9. Factors relevant to the recycling or reuse of components arising from the decommissioning and refurbishment of nuclear facilities

    International Nuclear Information System (INIS)

    1988-01-01

    The decommissioning and decontamination of nuclear facilities is a topic of great interest to many Member States of the International Atomic Energy Agency (IAEA) because of the large number of older nuclear facilities which are or soon will be retired from service. To assist in the development of the required decommissioning expertise, the IAEA is developing reports and recommendations which will eventually form an integrated information base covering in a systematic way the wide range of topics associated with decommissioning. This information is required so that Member States can decommission their nuclear facilities in a safe, timely and cost effective manner and the IAEA can effectively respond to requests for assistance. One area which warrants more detailed analyses is an assessment of the factors important to the recycling or reuse of components arising from the refurbishment or decommissioning of nuclear plants, the topic of the present report. The document provides an up to date review of the engineering, social, scientific and administrative factors relevant to the safe recycling or reuse of components arising from decommissioning or refurbishment of nuclear facilities. This report should be of interest to owners, operators, policy makers and regulators involved with nuclear facilities, especially those in developing countries. Refs, figs and tabs

  10. Recent trends in superalloys research for critical aero-engine components

    Energy Technology Data Exchange (ETDEWEB)

    Remy, Luc [Mine ParisTech, CNRS UMR 7633, 91 - Evry (France). Centre des Materiaux; Guedou, Jean-Yves [Snecma Safran Group, Moissy-Cramayel (France). Materials and Processes Dept.

    2010-07-01

    This paper is a brief survey of common research activity on superalloys for aero-engines between Snecma and Mines ParisTech Centre des Materiaux during recent years. First in disks applications, the development of new powder metallurgy superalloys is shown. Then grain boundary engineering is investigated in a wrought superalloy. Secondly, design oriented research on single crystals blades is shown: a damage model for low cycle fatigue is used for life prediction when cracks initiated at casting pores. The methodology developed for assessing coating life is illustrated for thermal barrier coating deposited on AMI single crystal superalloy. (orig.)

  11. Analysis of Effective and Internal Cyclic Stress Components in the Inconel Superalloy Fatigued at Elevated Temperature

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Miroslav; Petrenec, Martin; Polák, Jaroslav; Obrtlík, Karel; Chlupová, Alice

    2011-01-01

    Roč. 278, 4 July (2011), s. 393-398 ISSN 1022-6680. [European Symposium on Superalloys and their Application. Wildbad Kreuth, 25.5.2010-28.5.2010] R&D Projects: GA ČR GA106/08/1631 Institutional research plan: CEZ:AV0Z20410507 Keywords : low cycle fatigue * superalloys * high temperature * hysteresis loop * effective and internal stresses Subject RIV: JL - Materials Fatigue, Friction Mechanics; JL - Materials Fatigue, Friction Mechanics (UFM-A)

  12. Computer Refurbishment

    International Nuclear Information System (INIS)

    Ichiyen, Norman; Chan, Dominic; Thompson, Paul

    2004-01-01

    The major activity for the 18-month refurbishment outage at the Point Lepreau Generating Station is the replacement of all 380 fuel channel and calandria tube assemblies and the lower portion of connecting feeder pipes. New Brunswick Power would also take advantage of this outage to conduct a number of repairs, replacements, inspections and upgrades (such as rewinding or replacing the generator, replacement of shutdown system trip computers, replacement of certain valves and expansion joints, inspection of systems not normally accessible, etc.). This would allow for an additional 25 to 30 years. Among the systems to be replaced are the PDC's for both shutdown systems. Assessments have been completed for both the SDS1 and SDS2 PDC's, and it has been decided to replace the SDS2 PDCs with the same hardware and software approach that has been used successfully for the Wolsong 2, 3, and 4 and the Qinshan 1 and 2 SDS2 PDCs. For SDS1, it has been decided to use the same software development methodology that was used successfully for the Wolsong and Qinshan called the I A and to use a new hardware platform in order to ensure successful operation for the 25-30 year station operating life. The selected supplier is Triconex, which uses a triple modular redundant architecture that will enhance the robustness/fault tolerance of the design with respect to equipment failures

  13. Application of a multi-component mean field model to the coarsening behaviour of a nickel-based superalloy

    International Nuclear Information System (INIS)

    Anderson, M.J.; Rowe, A.; Wells, J.; Basoalto, H.C.

    2016-01-01

    A multi-component mean field model has been applied to predict the particle evolution of the γ′ particles in the nickel based superalloy IN738LC, capturing the transition from an initial multimodal particle distribution towards a unimodal distribution. Experiments have been performed to measure the coarsening behaviour during isothermal heat treatments using quantitative analysis of micrographs. The three dimensional size of the γ′ particles has been approximated for use in simulation. A coupled thermodynamic/mean field modelling framework is presented and applied to describe the particle size evolution. A robust numerical implementation of the model is detailed that makes use of surrogate models to capture the thermodynamics. Different descriptions of the particle growth rate of non-dilute particle systems have been explored. A numerical investigation of the influence of scatter in chemical composition upon the particle size distribution evolution has been carried out. It is shown how the tolerance in chemical composition of a given alloy can impact particle coarsening behaviour. Such predictive capability is of interest in understanding variation in component performance and the refinement of chemical composition tolerances. It has been found that the inclusion of misfit strain within the current model formulation does not have a significant affect upon predicted long term particle coarsening behaviour. Model predictions show good agreement with experimental data. In particular, the model predicts a reduced growth rate of the mean particle size during the transition from bimodal to unimodal distributions.

  14. Additive Manufacturing of IN100 Superalloy Through Scanning Laser Epitaxy for Turbine Engine Hot-Section Component Repair: Process Development, Modeling, Microstructural Characterization, and Process Control

    Science.gov (United States)

    Acharya, Ranadip; Das, Suman

    2015-09-01

    This article describes additive manufacturing (AM) of IN100, a high gamma-prime nickel-based superalloy, through scanning laser epitaxy (SLE), aimed at the creation of thick deposits onto like-chemistry substrates for enabling repair of turbine engine hot-section components. SLE is a metal powder bed-based laser AM technology developed for nickel-base superalloys with equiaxed, directionally solidified, and single-crystal microstructural morphologies. Here, we combine process modeling, statistical design-of-experiments (DoE), and microstructural characterization to demonstrate fully metallurgically bonded, crack-free and dense deposits exceeding 1000 μm of SLE-processed IN100 powder onto IN100 cast substrates produced in a single pass. A combined thermal-fluid flow-solidification model of the SLE process compliments DoE-based process development. A customized quantitative metallography technique analyzes digital cross-sectional micrographs and extracts various microstructural parameters, enabling process model validation and process parameter optimization. Microindentation measurements show an increase in the hardness by 10 pct in the deposit region compared to the cast substrate due to microstructural refinement. The results illustrate one of the very few successes reported for the crack-free deposition of IN100, a notoriously "non-weldable" hot-section alloy, thus establishing the potential of SLE as an AM method suitable for hot-section component repair and for future new-make components in high gamma-prime containing crack-prone nickel-based superalloys.

  15. Possible refurbishment of Point Lepreau

    International Nuclear Information System (INIS)

    White, R.M.; Groom, S.H.; Thompson, P.D.; Barclay, J.M.; Allen, P.J.

    2001-01-01

    In February 2000, the NB Power Board of Directors approved Phase one of a project to produce a business case including a detailed scope and estimate associated with the possible refurbishment of the Point Lepreau Generating Station (PLGS). The Preliminary plan for refurbishment projects an 18-month outage starting as early as the spring of 2006. If the station were to be refurbished, then it would be run for another 25 to 30 years. The decision on whether or not to refurbish PLGS has not been made and is not expected until the summer of 2002. The results of the first phase of the project will be used to prepare a detailed business case that will be presented to the NB Power board of directors in January of 2002. At that time a decision will be made as to whether to refurbish the unit, or obtain other means of replacing the energy produced by PLGS. The station currently produces about a third of the power generated within the province. If the business case is approved, all-380 Pressure Tubes and Calandria Tubes, along with their related End Fittings and Feeders would be replaced. This material would be stored in new storage vaults to be constructed at the existing on-site Waste Management Facility. Replacement of other station components will be performed as required, as determined from the results of a comprehensive Plant Condition Assessment. The condition assessments build on work done under the Plant Life Management Program. Point Lepreau Generating Station has operated well since start of commercial operation in early 1983. With a lifetime capacity factor of about 84% (up to the end of 2000), it has proven to be an economic and environmentally sound electricity provider. The station has also had a significant positive economic impact in Southern New Brunswick, employing over 600 people. However the Pressure Tubes and Feeders are nearing the point in time in which they will exceed their fitness for service criteria. Although tubes can be replaced on an

  16. Possible refurbishment of Point Lepreau

    International Nuclear Information System (INIS)

    White, R.M.; Groom, S.H.; Thompson, P.D.; Barclay, J.M.; Allen, P.J.

    2001-01-01

    In February 2000, the NB Power Board of Directors approved Phase one of a project to produce a business case including a detailed scope and estimate associated with the possible refurbishment of the Point Lepreau Generating Station (PLGS). The Preliminary plan for refurbishment projects an 18-month outage starting as early as the spring of 2006. If the station were to be refurbished, then it would be run for another 25 to 30 years. The decision on whether or not to refurbish PLGS has not been made and is not expected until the summer of 2002. The results of the first phase of the project will be used to prepare a detailed business case that will be presented to the NB Power board of directors in January of 2002. At that time a decision will be made as to whether to refurbish the unit, or obtain other means of replacing the energy produced by PLGS. The station currently produces about a third of the power generated within the province. If the business case is approved, all-380 Pressure Tubes and Calandria Tubes, along with their related End Fittings and Feeders would be replaced. This material would be stored in new storage vaults to be constructed at the existing on-site Waste Management Facility. Replacement of other station components will be performed as required, as determined from the results of a comprehensive Plant Condition Assessment. The condition assessments build on work done under the Plant Life Management Program. Point Lepreau Generating Station has operated well since start of commercial operation in early 1983. With a lifetime capacity factor of about 84% (up to the end of 2000), it has proven to be an economic and environmentally sound electricity provider. The station has also had a significant positive economic impact in Southern New Brunswick, employing over 600 people. However the Pressure Tubes and Feeders are nearing the point in time in which they will exceed their fitness for service criteria. Although tubes can be replaced on an

  17. Waste drum refurbishment

    International Nuclear Information System (INIS)

    Whitmill, L.J.

    1996-01-01

    Low-carbon steel, radioactive waste containers (55-gallon drums) are experiencing degradation due to moisture and temperature fluctuations. With thousands of these containers currently in use; drum refurbishment becomes a significant issue for the taxpayer and stockholders. This drum refurbishment is a non-intrusive, portable process costing between 1/2 and 1/25 the cost of repackaging, depending on the severity of degradation. At the INEL alone, there are an estimated 9,000 drums earmarked for repackaging. Refurbishing drums rather than repackaging can save up to $45,000,000 at the INEL. Based on current but ever changing WIPP Waste Acceptance Criteria (WAC), this drum refurbishment process will restore drums to a WIPP acceptable condition plus; drums with up to 40% thinning o the wall can be refurbished to meet performance test requirements for DOT 7A Type A packaging. A refurbished drum provides a tough, corrosion resistant, waterproof container with longer storage life and an additional containment barrier. Drums are coated with a high-pressure spray copolymer material approximately .045 inches thick. Increase in internal drum temperature can be held to less than 15 F. Application can be performed hands-on or the equipment is readily adaptable and controllable for remote operations. The material dries to touch in seconds, is fully cured in 48 hours and has a service temperature of -60 to 500 F. Drums can be coated with little or no surface preparation. This research was performed on drums however research results indicate the coating is very versatile and compatible with most any material and geometry. It could be used to provide abrasion resistance, corrosion protection and waterproofing to almost anything

  18. E-waste Management and Refurbishment Prediction (EMARP) Model for Refurbishment Industries.

    Science.gov (United States)

    Resmi, N G; Fasila, K A

    2017-10-01

    This paper proposes a novel algorithm for establishing a standard methodology to manage and refurbish e-waste called E-waste Management And Refurbishment Prediction (EMARP), which can be adapted by refurbishing industries in order to improve their performance. Waste management, particularly, e-waste management is a serious issue nowadays. Computerization has been into waste management in different ways. Much of the computerization has happened in planning the waste collection, recycling and disposal process and also managing documents and reports related to waste management. This paper proposes a computerized model to make predictions for e-waste refurbishment. All possibilities for reusing the common components among the collected e-waste samples are predicted, thus minimizing the wastage. Simulation of the model has been done to analyse the accuracy in the predictions made by the system. The model can be scaled to accommodate the real-world scenario. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Laser Engineered Net Shape (LENS) Technology for the Repair of Ni-Base Superalloy Turbine Components

    Science.gov (United States)

    Liu, Dejian; Lippold, John C.; Li, Jia; Rohklin, Stan R.; Vollbrecht, Justin; Grylls, Richard

    2014-09-01

    The capability of the laser engineered net shape (LENS) process was evaluated for the repair of casting defects and improperly machined holes in gas turbine engine components. Various repair geometries, including indentations, grooves, and through-holes, were used to simulate the actual repair of casting defects and holes in two materials: Alloy 718 and Waspaloy. The influence of LENS parameters, including laser energy density, laser scanning speed, and deposition pattern, on the repair of these defects and holes was studied. Laser surface remelting of the substrate prior to repair was used to remove machining defects and prevent heat-affected zone (HAZ) liquation cracking. Ultrasonic nondestructive evaluation techniques were used as a possible approach for detecting lack-of-fusion in repairs. Overall, Alloy 718 exhibited excellent repair weldability, with essentially no defects except for some minor porosity in repairs representative of deep through-holes and simulated large area casting defects. In contrast, cracking was initially observed during simulated repair of Waspaloy. Both solidification cracking and HAZ liquation cracking were observed in the repairs, especially under conditions of high heat input (high laser power and/or low scanning speed). For Waspaloy, the degree of cracking was significantly reduced and, in most cases, completely eliminated by the combination of low laser energy density and relatively high laser scanning speeds. It was found that through-hole repairs of Waspaloy made using a fine powder size exhibited excellent repair weldability and were crack-free relative to repairs using coarser powder. Simulated deep (7.4 mm) blind-hole repairs, representative of an actual Waspaloy combustor case, were successfully produced by the combination use of fine powder and relatively high laser scanning speeds.

  20. Last PS magnet refurbished

    CERN Multimedia

    2009-01-01

    PS Magnet Refurbishment Programme Completed. The 51st and final refurbished magnet was transported to the PS on Tuesday 3 February. The repair and consolidation work on the PS started back in 2003 when two magnets and a busbar connection were found to be faulty during routine high-voltage tests. The cause of the fault was a combination of age and radiation on electrical insulation. After further investigation the decision was taken to overhaul half of the PS’s 100 magnets to reduce the risk of a similar fault. As from 20 February the PS ring will start a five-week test programme to be ready for operation at the end of March.

  1. Foundation helps refurbish buildings

    International Nuclear Information System (INIS)

    Camenzind, B.

    2006-01-01

    This article looks at the activities of the Swiss 'Climate-Cent' foundation, which is helping support the energetic refurbishment of building envelopes. The conditions which have to be fulfilled to receive grants are explained. Work supported includes the replacement of windows and the insulation of roofs and attics as well as outside walls. Details on the financial support provided and examples of projects supported are given. The source of the finance needed to provide such support - a voluntary levy on petrol - and further support provided in certain Swiss cantons is commented on

  2. Ion beam analysis of gas turbine blades: evaluation of refurbishment ...

    Indian Academy of Sciences (India)

    Abstract. Refurbishment of hot components of gas turbines damaged in the harsh working environments is neces- ... 3000 r.p.m. and fluid forces that can cause fracture, yield- ... 800, 1200 and 2000 grit by employing mechanical grinding.

  3. Point Lepreau refurbishment - update 5

    International Nuclear Information System (INIS)

    White, R.M.; Eagles, E.R.; Hickman, C.N.; Baker, R.; Thompson, P.D.; Howieson, J.Q.; Ichiyen, N.

    2005-01-01

    NB Power Nuclear is planning to conduct a 18-month maintenance outage of the Point Lepreau Generating Station (PLGS) beginning in April 2008. The major activity would be the replacement of all 380 Fuel Channel and Calandria Tube assemblies and connecting feeder pipes. This activity is referred to as Retube. NB Power Nuclear would also take advantage of this outage to conduct a number of repairs, replacements, inspection and upgrades (such as rewinding or replacing the generator, replacement of shutdown system trip computers, replacement of certain valves and expansion joints, inspection of systems not normally accessible, etc.). These collective activities are referred to as Refurbishment. This would allow the station to operate for an additional 25 to 30 years. The scope or the project was determined [mm the outcome of a two year study involving a detailed condition assessment of the station which examined Issues relating to ageing and obsolescence, along with a detailed review or Safety and Licensing issues associated with extended operation. The Refurbishment outage would be preceded by a detailed Engineering Project Phase that would: Finalize details of the Retube process including modeling, tooling development, site facilities and training of personnel. Perform necessary engineering activities related to design modifications. Construct the new waste storage structures to house Retube Waste and other additional waste storage structures for the extended life of the station. Setup necessary temporary construction facilities (offices, storage areas, change moms, decontamination an maintenance areas) to support Retube. Procure equipment and components. Perform detailed outage planning. Initiate development of detailed commissioning as well as lay-up, monitoring and return to service procedures. At the present time, the NB Power Nuclear Board of Directors and the New Brunswick Provincial government are reviewing a proposal for a lease arrangement from Bruce Power

  4. Refurbishments of RF systems

    International Nuclear Information System (INIS)

    Baelde, J.L.

    1998-01-01

    This document describes the activities of the R.F. System group during the years 1995-1996 in the frame of the refurbishment of the control system at GANIL accelerator. Modifications concerning the following sub-assemblies are mentioned: 1. voltage standards; 2. link card between the step by step motor control and the local control systems; 3. polarization system; 4. computer software for different operations. Also reported is the installation of ECR 4 source for the CO2. In this period the R2 Regrouping system has been installed, tested and put into operation. Several problems concerning the mechanical installation of the coupling loop and other problems related to the electronics operation were solved. The results obtained with the THI machine are presented

  5. Current status of JMTR refurbishment project

    International Nuclear Information System (INIS)

    Kaminaga, Masanori; Niimi, Motoji; Hori, Naohiko; Takahashi, Kunihiro; Kanno, Masaru; Nakagawa, Tetsuya; Nagao, Yoshiharu; Ishihara, Masahiro; Kawamura, Hiroshi

    2010-02-01

    The JMTR is a light water moderated and cooled, beryllium reflected tank- type reactor using LUE silicide plate-type fuels. Its thermal power is 50 MW, maximum thermal and fast neutron flux is 4x10 18 m -2 s -1 . First criticality was achieved in March 1968, and its operation was stopped from August, 2006 for the refurbishment. The refurbishment is scheduled from the beginning of FY2007 to the end of FY2010. The renewed and upgraded JMTR will be re-started from FY2011. An investigation on aged components (aged-investigation) was carried out for concrete structures of the JMTR reactor building, exhaust stack, etc., and for tanks in the primary cooling system, heat exchangers, pipes in the secondary cooling system, cooling tower, emergency generators and so on, in order to identify their integrity. The aged-investigation was carried out at the beginning of FY2007. As a result, some components were decided to replace from viewpoints of future maintenance and improvement of reliability, and some components or structures were decided to repair. A visual inspection of inner side of the pressure vessel was carried out using an underwater camera in FY2008, and no serious damage was observed. Up to now, refurbishment works are in progress according to the planned schedule. In FY2009, motors of primary cooling pumps, secondary cooling pumps, motors of drain pumps, pump in the primary water transfer line to the water purification system, beryllium reflector frame, low-voltage motor control centers are to be replaced. A nuclear instrumentation system, process control system, safety protection system and so on are to be replaced in FY2010. In this paper, current status of JMTR refurbishment project is presented. (author)

  6. Refurbishment of hydropower generation plants

    International Nuclear Information System (INIS)

    Kofler, W.

    2001-01-01

    This article presents the factors taken into consideration and the methods used for the management of refurbishment work in the hydropower installations of the TUWAG - a Tyrolean hydropower company in Austria. The technical and financial advantages to be gained from refurbishment are discussed and the requirements placed on the structuring of refurbishment projects are described. Various factors such as plant operation and maintenance, increased returns through better efficiency and cost reduction through lower wear and tear and reduced risk of failure are discussed. Annexes to the article cover monitoring and measurement techniques, the simulation of mechanical and hydraulic conditions, profitability calculations and turbine management

  7. Refurbishment of the LECI

    International Nuclear Information System (INIS)

    Blanc, J. Y.; Cheron, C.

    2001-01-01

    The LECI is a hot laboratory built in Saclay in the early sixties for examinations on fuel rods, with 25 hot cells. Around 1995, a refurbishment programme up to 2004 was decided and started. It includes the renovation of about half of the cells of the existing building and the construction of a new building with about twenty lead-shielded hot cells for mechanical testing. At mid 2001, this paper presents the status of the project and the perspectives for the next years. These modifications aims: -To increase sample preparation and examination capacities on nuclear metals: mainly zirconium, steel and aluminium alloys. -To keep existing P. I. facilities on short P. W. R. fuel rod as support for ramp testing programmes in the nearby Osiris reactor and as support for new cladding development programmes. -To gather in LECI mechanical testing facilities which are up to now located in another facility to be shut down at the end of 2003. Concerning the existing building, most of the planned refurbishment has been performed and 10 cells have been cleaned and 8 of them will be reequipped at the end of 2001: a metallography line with new microscope, hardness testing, periscopes, TEM thin foil and EPMA preparation, two cells for tooling mechanical samples (milling machine, lathe, spark erosion), one cell for clad creep testing on long term storage conditions and a cell with a 250 kN tensile machine. The new building is built, the lead cells will be installed in 2002 and most of the scientific equipment have been ordered. They include: wire erosion machining 3 tensile machines with extensometry, 2 Charpy, different creep and internal pressure machines, autoclaves EPMA and Raman analysis. The schedule is to open this building to irradiated materials ( no fuel except on EPMA) at the end of 2003. Some difficulties such as the public enquires have been successfully overcome, some financial constraints have delayed the project of about one year, and technical difficulties have

  8. Refurbishment of industrial buildings

    International Nuclear Information System (INIS)

    Gustafsson, Stig-Inge

    2006-01-01

    When a building is subject for refurbishment, there is a golden opportunity to change its behavior as an energy system. This paper shows the importance of careful investigations of the processes, the climate shield and the heating systems already present in the building before measures are implemented in reality. A case study is presented dealing with a carpentry factory. The building is poorly insulated according to standards today, and initially it was assumed that a better thermal shield would be of vital importance in order to reach optimal conditions. Instead, it is shown that the main problem is the ordinary heating system. This uses steam from a wood chips boiler and the wood chips come from the manufacturing processes. These wood chips are, therefore, a very cheap fuel. The boiler had, during decades of use, slowly degraded into a poor state. Hence, aero-tempers using expensive electricity have been installed to remedy the situation. These use not only expensive kWh but also very expensive kW due to the electricity tariff. It is shown that electricity for heating purposes must be abandoned and further, that this could be achieved at a surprisingly small cost. By stopping a large waste of steam, it was possible to find resources, in the form of unspent money, for further mending the existing heating system. Not only economy but also environmental hazards in the form of CO 2 emissions urges us to abandon electricity and instead use heat from cheap biomass fired boilers. Such equipment saves environment at the same time it saves money

  9. Reactor refurbishment in an outage environment

    International Nuclear Information System (INIS)

    Gowthorpe, P.; Hoare, R.

    2012-01-01

    Reactor life extension has typically been performed during specific refurbishment outages. These outages are long and costly due to the sheer complexity of the scope, not to mention the ever present discovery work. A scope of this size requires a huge labour force to execute, which poses significant challenges. The work is difficult to staff with qualified people able to execute the work smoothly and managing the required labour pool problematic. Cost and time overruns are inevitable in that environment. Reducing the cost and schedule is critical to the long term viability of reactor refurbishment projects. With planning, the total cost of the refurbishment can be reduced by managing the inspection and repairs during normal outages. Identifying what activities need to be done each outage for the life of the reactor and bringing the latest technology can make this viable. Tightly planned outages with a small well trained labour force will go a long way to reducing costs. The suite of services and tooling available to the utilities to manage their reactor integrity has improved significantly in recent years and continues to evolve. New feeder inspection technologies can provide improved inspection results for the complex feeder geometry. These improvements lead to more accurate wear rates and better predictions of component life. Feeders that need replacement based on improved inspection techniques can be replaced systematically during regular outages rather than specific refurbishment outages. Targeting areas rather than entire feeders reduces time, dose and cost. In cases where feeder replacement isn't feasible or where unpredicted wear is found, a feeder weld overlay process can be used. To manage the reactor work, new data systems are under development that allow for effective tracking of each activity performed and outcomes in a single package. (author)

  10. Sustainability Potentials of Housing Refurbishment

    Directory of Open Access Journals (Sweden)

    Behzad Sodagar

    2013-03-01

    Full Text Available The benefits of choosing refurbishment over new build have recently been brought into focus for reducing environmental impacts of buildings. This is due to the fact that the existing buildings will comprise the majority of the total building stocks for years to come and hence will remain responsible for the majority of greenhouse gas emissions from the sector. This paper investigates the total potentials of sustainable refurbishment and conversion of the existing buildings by adopting a holistic approach to sustainability. Life Cycle Assessment (LCA and questionnaires have been used to analyse the environmental impact savings (Co2e, improved health and well-being, and satisfaction of people living in refurbished homes. The results reported in the paper are based on a two year externally funded research project completed in January 2013.

  11. LMZ experience in refurbishment of hydroturbine equipment

    Energy Technology Data Exchange (ETDEWEB)

    Sotnikov, Anatoly A. [LMZ, St. Petersburg (Russian Federation). Div. of Hydraulic Machine

    2000-07-01

    AO LMZ experience in refurbishment of hydroturbine equipment is generalized. Hydraulic turbines of many power stations having been in service of more than 30 years need rehabilitation and modernization. As a rule, the following problems are solved in the process of refurbishment works: increase of turbine efficiency and output, ensuring of reliable operation of the equipment during the next length of life, ensuring the environmental safety of the equipment, furnishing of the power station with up to date automatic control systems. The process of refurbishment used by LMZ is described. The examples of refurbishment are given. (author)

  12. Model for Refurbishment of Heritage Buildings

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2014-01-01

    the Heritage Agency, the Danish Working Environment Authority and the owner as a team cooperated in identifying feasible refurbishments. In this case, the focus centered on restoring and identifying potential energy savings and deciding on energy upgrading measures for the listed complex. The refurbished...... with the requirements for the use of the building. The model focuses on the cooperation and dialogue between authorities and owners, who refurbish heritage buildings. The developed model was used for the refurbishment of the listed complex, Fæstningens Materialgård. Fæstningens Materialgård is a case study where...

  13. Refurbishing tritium contaminated ion sources

    International Nuclear Information System (INIS)

    Wright, K.E.; Carnevale, R.H.; McCormack, B.E.; Stevenson, T.; Halle, A. von

    1995-01-01

    Extended tritium experimentation on TFTR has necessitated refurbishing Neutral Beam Long Pulse Ion Sources (LPIS) which developed operational difficulties, both in the TFTR Test Cell and later, in the NB Source Refurbishment Shop. Shipping contaminated sources off-site for repair was not permissible from a transport and safety perspective. Therefore, the NB source repair facility was upgraded by relocating fixtures, tooling, test apparatus, and three-axis coordinate measuring equipment; purchasing and fabricating fume hoods; installing exhaust vents; and providing a controlled negative pressure environment in the source degreaser/decon area. Appropriate air flow monitors, pressure indicators, tritium detectors and safety alarms were also included. The effectiveness of various decontamination methods was explored while the activation was monitored. Procedures and methods were developed to permit complete disassembly and rebuild of an ion source while continuously exhausting the internal volume to the TFTR Stack to avoid concentrations of tritium from outgassing and minimize personnel exposure. This paper presents upgrades made to the LPIS repair facility, various repair tasks performed, and discusses the effectiveness of the decontamination processes utilized

  14. Project Plan Remote Target Fabrication Refurbishment Project

    International Nuclear Information System (INIS)

    Bell, Gary L.; Taylor, Robin D.

    2009-01-01

    In early FY2009, the DOE Office of Science - Nuclear Physics Program reinstated a program for continued production of 252 Cf and other transcurium isotopes at the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL). The FY2009 major elements of the workscope are as follows: (1) Recovery and processing of seven transuranium element targets undergoing irradiation at the High Flux Isotope Reactor (HFIR) at ORNL; (2) Development of a plan to manufacture new targets for irradiation beginning in early- to mid-FY10 to supply irradiated targets for processing Campaign 75 (TRU75); and (3) Refurbishment of the target manufacturing equipment to allow new target manufacture in early FY10 The 252 Cf product from processing Campaign 74 (recently processed and currently shipping to customers) is expected to supply the domestic demands for a period of approximately two years. Therefore it is essential that new targets be introduced for irradiation by the second quarter of FY10 (HFIR cycle 427) to maintain supply of 252 Cf; the average irradiation period is ∼10 HFIR cycles, requiring about 1.5 calendar years. The strategy for continued production of 252 Cf depends upon repairing and refurbishing the existing pellet and target fabrication equipment for one additional target production campaign. This equipment dates from the mid-1960s to the late 1980s, and during the last target fabrication campaign in 2005- 2006, a number of component failures and operations difficulties were encountered. It is expected that following the target fabrication and acceptance testing of the targets that will supply material for processing Campaign 75 a comprehensive upgrade and replacement of the remote hot-cell equipment will be required prior to subsequent campaigns. Such a major refit could start in early FY 2011 and would take about 2 years to complete. Scope and cost estimates for the repairs described herein were developed, and authorization for the work

  15. Refractory metal based superalloys

    International Nuclear Information System (INIS)

    Alonso, Paula R.; Vicente, Eduardo E.; Rubiolo, Gerardo H.

    1999-01-01

    Refractory metals are looked as promising materials for primary circuits in fission reactors and even as fusion reactor components. Indeed, superalloys could be developed which take advantage of their high temperature properties together with the benefits of a two- phase (intermetallic compound-refractory metal matrix) coherent structure. In 1993, researchers of the Office National d'Etudes et de Recherches Aerospatiales of France reported the observation of such a coherent structure in the Ta-Ti-Zr-Al-Nb-Mo system although the exact composition is not reported. The intermetallic compound would be Ti 2 AlMo based. However, the formation of this compound and its possible coexistence with a disordered bcc phase in the ternary system Ti-Al-Mo is a controversial subject in the related literature. In this work we develop a technique to obtain homogeneous alloys samples with 50 Ti-25 Al-25 Mo composition. The resulting specimens were characterized by optical and electronic metallography (SEM), microprobe composition measurements (EPMA) and X-ray diffraction (XRD) analyses. The results show the evidence for a bcc (A2→B2) ordering reaction in the Ti-Al-Mo system in the 50 Ti-25 Al-25 Mo composition. (author)

  16. Overview of refurbishment project of JMTR

    Energy Technology Data Exchange (ETDEWEB)

    Izumo, Hironobu; Hori, Naohiko; Kaminaga, Masanori; Kusunoki, Tsuyoshi; Ishihara, Masahiro; Komori, Yoshihiro; Suzuki, Masahide; Kawamura, Hiroshi [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan)

    2012-03-15

    The refurbishment project of the JMTR from the beginning of JFY 2007 was promoted with two subjects; the one is the replacement of reactor components, and the other is the construction of new irradiation facilities. On the replacement of reactor components, an investigation on aged components (aged-investigation) was carried out, for concrete structures, tanks, tubes in order to identify their integrity. After the investigation, some components were decided to replace from viewpoints of future maintenance and improvement of reliability. On the construction of new irradiation facilities, corresponding to the user's irradiation request, new irradiation facilities, such as irradiation test facilities and equipments for LWRs materials/fuels, were installed in the JMTR. Furthermore, in June 2010, 'birth of the nuclear techno-park with the JMTR' was selected by Japanese Government. The new project is to install new irradiation facilities, such as irradiation facility and equipments for Mo-99 production and PIE equipments to JMTR until JFY2012. The New JMTR will be utilized fully by wide fields of users. Moreover, the JMTR will also contribute the promotion on research and development of the nuclear energy from basic to applied fields as an internationally utilized facility under the international/Asian network collaborations. (author)

  17. Fatigue studies of superalloys in Japan

    International Nuclear Information System (INIS)

    Kitagawa, Masaki

    1985-01-01

    In the past 15 years, several national projects were advanced to develop high temperature machinery, such as high temperature gas-cooled reactors, gas turbines and fusion reactors. Before, the studies on the strength of superalloys were rarely carried out, however, by the above research works, superalloys are in rapid progress. Because these machinery are subjected to temperature cycles and vibration stress, the fatigue failure is the main concern in the safety analysis of the components. The purpose of this paper is to summarize the present status of the fatigue research on the alloys for high temperature use in Japan. The superalloys used for gas turbine and HTGR components are listed, and the materials tested were mostly the alloys of nickel base, cobalt base or iron base. In the above national projects, the main purpose was to clarify the high temperature properties including fatigue properties, to develop the method of forecasting the life span and to develop better materials. As the topics about the fatigue research on superalloys, the development of the method for forecasting the life span, the effect of directional solidification, coating and HIP process on the fatigue strength of gas turbine materials, the effect of helium and aging on the fatigue strength of HTGR materials, the fatigue strength of weldment of HTGR materials and others are reported. (Kako, I.)

  18. Space Telescope maintenance and refurbishment

    Science.gov (United States)

    Trucks, H. F.

    1983-01-01

    The Space Telescope (ST) represents a new concept regarding spaceborne astronomical observatories. Maintenance crews will be brought to the orbital worksite to make repairs and replace scientific instruments. For major overhauls the telescope can be temporarily returned to earth with the aid of the Shuttle. It will, thus, be possible to conduct astronomical studies with the ST for two decades or more. The five first-generation scientific instruments used with the ST include a wide field/planetary camera, a faint object camera, a faint object spectrograph, a high resolution spectrograph, and a high speed photometer. Attention is given to the optical telescope assembly, the support systems module, aspects of mission and science operations, unscheduled maintenance, contingency orbital maintenance, planned on-orbit maintenance, ground maintenance, ground refurbishment, and ground logistics.

  19. Modelling and simulation of superalloys. Book of abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Rogal, Jutta; Hammerschmidt, Thomas; Drautz, Ralf (eds.)

    2014-07-01

    Superalloys are multi-component materials with complex microstructures that offer unique properties for high-temperature applications. The complexity of the superalloy materials makes it particularly challenging to obtain fundamental insight into their behaviour from the atomic structure to turbine blades. Recent advances in modelling and simulation of superalloys contribute to a better understanding and prediction of materials properties and therefore offer guidance for the development of new alloys. This workshop will give an overview of recent progress in modelling and simulation of materials for superalloys, with a focus on single crystal Ni-base and Co-base alloys. Topics will include electronic structure methods, atomistic simulations, microstructure modelling and modelling of microstructural evolution, solidification and process simulation as well as the modelling of phase stability and thermodynamics.

  20. OSIRIS. Refurbishment and management of ageing effects

    International Nuclear Information System (INIS)

    Joly, C.; Guidez, J.; Contenson, G. de; Marin, J.P.

    1995-01-01

    OSIRIS, one of the French CEA research reactors (Saclay, France), achieved criticality for the first time on July 1966. During the 29 running years OSIRIS was mainly devoted to production and technological irradiations. To satisfy these objectives, OSIRIS is equipped by different test facilities allowing: the long time irradiation of different material including fuel rods, reactor vessel materials, fusion reactor components; the power ramps of fuel rods; the activation analysis; the neutron-radiography of materials and test sections... All the foreseen irradiation programmes will only be possible if safety and high performances of the reactor are guaranteed. That is why a continuous maintenance and improvement programme has taken place during the whole life of the reactor. This paper gives an overview of this programme, mainly about the part conducted during the last years. Details about characteristics of the reactor, history of experiments, maintenance programme, instrumentation and control system, electrotechnical low voltage supply network, decay tanks and water purification system are summarized. The paper focuses on the refurbishment or the replacement of the main components connected to the continuous maintenance programme to guarantee the reliability, the safety and the high performances of the reactor. (J.S.). 2 refs., 8 figs., 2 tabs

  1. Research reactor modernization and refurbishment

    International Nuclear Information System (INIS)

    2009-08-01

    Many recent, high profile research reactor unplanned shutdowns can be directly linked to different challenges which have evolved over time. The concept of ageing management is certainly nothing new to nuclear facilities, however, these events are highlighting the direct impact unplanned shutdowns at research reactors have on various stakeholders who depend on research reactor goods and services. Provided the demand for these goods and services remains strong, large capital projects are anticipated to continue in order to sustain future operation of many research reactors. It is within this context that the IAEA organized a Technical Workshop to launch a broader Agency activity on research reactor modernization and refurbishment (M and R). The workshop was hosted by the operating organization of the HOR Research Reactor in Delft, the Netherlands, in October 2006. Forty participants from twenty-three countries participated in the meeting: with representation from Africa, Asia Pacific, Eastern Europe, North America, South America and Western Europe. The specific objectives of this workshop were to present facility reports on completed, existing and planned M and R projects, including the project objectives, scope and main characteristics; and to specifically report on: - the project impact (planned or actual) on the primary and key supporting motivation for the M and R project; - the project impact (planned or actual) on the design basis, safety, and/or regulatory-related reports; - the project impact (planned or actual) on facility utilization; - significant lessons learned during or following the completion of M and R work. Contributions from this workshop were reviewed by experts during a consultancy meeting held in Vienna in December 2007. The experts selected final contributions for inclusion in this report. Requests were also distributed to some authors for additional detail as well as new authors for known projects not submitted during the initial 2006 workshop

  2. Gentilly-2 refurbishment pre-project

    International Nuclear Information System (INIS)

    Pageau, Rene; Doyon, Martial; Rheaume, M.R.

    2002-01-01

    The conceptual design life of Gentilly-2 station is 30 years and the station was put in service in 1982. Hydro-Quebec has initiated a project to assess the refurbishment of the station in the horizon 2008-2010 and for an expected life extension of 25 years. The reactor has been successfully operated since its first full-power operation in early 80's, nearly 20 years ago. Although the overall performance of Gentilly-2 continues to be very good, it is reasonable to expect that age-related degradation of key plant components will have an increasing impact on operations as the plant continues to age. The replacement of the reactor channels component is required around 2008-2009. The replacement of the reactor tubes is a major activity and it is necessary to assess the capability of the station to operate safely and reliably for a an extended period of 25 years bringing the design life of the station to over 50 years. The challenges associated with extended life operation until at least 2030-33 horizon are to maintain the margin of safety for plant operations by ensuring reliability of safety-related systems, to reduce plant unavailability due to age-related component failures, and to minimize the costs for repairs and replacement of aging components. As shown on the next figure, the overall project is expected to spread over an 8 years period starting in 2001. A project feasibility study (phase-1) of four (4) years has been planned to assess the plant condition and to make an overall safety review. This project phase will confirm the economical viability of extended operation. A period of thirty-nine (39) months would be necessary for the procurement and manufacturing of all the reactor components, and for the engineering work related to safety and economic improvements. Reactor channel replacement is planned for an outage not exceeding 18 months. (author)

  3. Refurbishment of Point Lepreau Generating Station

    International Nuclear Information System (INIS)

    Thompson, P.D.; Jaitly, R.; Ichiyen, N.; Petrilli, M.A.

    2004-01-01

    NB Power is planning to conduct an 18-month maintenance outage of the Point Lepreau Generating Station (PLGS) beginning in April 2008. The major activity would be the replacement of all 380 Fuel Channel and Calandria Tube Assemblies and the connecting feeder pipes. This activity is referred to as Retube. NB Power would also take advantage of this outage to conduct a number of repairs, replacements, inspections and upgrades (such as rewinding or replacing the generator, replacement of shutdown system trip computers, replacement of certain valves and expansion joints, inspection of systems not normally accessible, etc). These collective activities are referred to as Refurbishment. This would allow the station to operate for an additional 25 to 30 years. The scope of the project was determined from the outcome of a two-year study involving a detailed condition assessment of the station that examined issues relating to ageing and obsolescence. The majority of the plant components were found to be capable of supporting extended operation without needing replacement or changes. In addition to the condition assessment, a detailed review of Safety and Licensing issues associated with extended operation was performed. This included a review of known regulatory and safety issues, comparison of the station against current codes and standards, and comparison of the station against safety related modifications made to more recent CANDU 6 units. Benefit cost analyses (BCA) were performed to assist the utility in determining which changes were appropriate to include in the project scope. As a Probabilistic Safety Assessment (PSA) for PLGS did not exist at the time, a risk baseline for the station had to be determined for use in the BCA. Extensive dialogue with the Canadian Nuclear Safety Commission staff was also undertaken during this phase. A comprehensive Licensing Framework was produced upon which the CNSC provided feedback to NB Power. This feedback was important in terms of

  4. The BR2 refurbishment programme: achievements and two years operation feedback

    International Nuclear Information System (INIS)

    Gubel, P.; Dekeyser, J.; Koonen, E.; Van der Auwera, J.

    1999-01-01

    The BR2 reactor was shutdown end of June 1995 for an extensive refurbishment after more than 30 years utilization. The beryllium matrix needed to be replaced and the aluminium vessel inspected for an envisaged 15 year life extension. Other aspects of the refurbishment programme aimed at the reliability and availability of the installations, safety of operation and compliance with modern safety standards. The reactor was started again in' April '97 and operated only for three cycles in 1997. These first irradiation cycles were intended as a demonstration of the safety and reliability of all components and systems after refurbishment. Also during the extended shutdowns non-critical refurbishment tasks were allowed to be continued and finalized. At the request of the Safety Authorities, some modifications and studies are still in progress without perturbation of the reactor operation. (author)

  5. Energetic Refurbishment of Historic Brick Buildings

    DEFF Research Database (Denmark)

    Zagorskas, Jurgis; Mykolas Paliulis, Grazvydas; Burinskiene, Marija

    2013-01-01

    Building standards for energy effectiveness are increasing constantly and the market follows these changes by constructing new buildings in accordance with standards and refurbishment of the existing housing stock. Comprehensive trends in European construction market show tremendous increase...

  6. Refurbishment of JMTR pure water facility

    International Nuclear Information System (INIS)

    Asano, Norikazu; Hanakawa, Hiroki; Kusunoki, Hidehiko; Satou, Shinichi

    2012-05-01

    In the refurbishment of JMTR, facilities were classified into which (1) were all updated, (2) were partly updated, and (3) were continuance used by the considerations of the maintenance history, the change parts availability and the latest technology. The JMTR pure water facility was classified into all updated facility based on the consideration. The Update construction was conducted in between FY2007 and FY2008. The refurbishment of JMTR pure water facility is summarized in this report. (author)

  7. Superalloy applications in the fast breeder reactor

    International Nuclear Information System (INIS)

    Powell, R.W.

    1976-01-01

    The economics of the LMFBR are dependent on the breeding of new fuel in the reactor core and this can be improved by the use of advanced alloys as core structural components. The environment of the core makes superalloys a natural choice for these components, but phenomena related directly to neutron irradiation necessitate extensive testing. Consequently, commercially-available superalloys, together with a number of developmental alloys are being tested in existing LMFBR's and by simulation techniques to determine the best alloy for use in the LMFBR core. It presently appears that such materials will indeed be capable of the performance required, and will greatly facilitate the commercial realization of the fast breeder reactor

  8. EPIQR - a decision making tool for apartment building refurbishment

    Energy Technology Data Exchange (ETDEWEB)

    Caccavelli, D. [Centre Scientifique et Technique du Batiment, Cedex (France); Balaras, C. [National Observatory of Athens, Athens (Greece); Bluyssen, P. [TNO Building and Construction Research, Delft (Netherlands); Flourentzou, F. [Ecole Polytechnique Federale de Lausanne, Lausanne (France); Jaggs, M. [Building Research Establishment, Watford (United Kingdom); Wetzel, C. [Fraunhofer-Institut fur Bauphysik, Holzkirchen (Germany); Wittchen, K. [Danish Building Reasearch Institute, Hoersholm (Denmark)

    1999-11-01

    In a large majority of European countries, the amount of the maintenance and refurbishment works represents nearly 50% of the total amount spent in the building sector. New requirements are being added to the necessity of maintaining or re-establishing the building stock`s usage value. They are linked to the determination to reduce energy consumption, pollutant emissions, work site wastes, to improve the Indoor Environment Quality and all the modern conveniences inside apartment. Aware of this matter, the European Community has launched a two-year European research project, entitled EPIQR (Energy Performance, Indoor Environmental Quality, Retrofit) involving seven research institutions in the frame of the JOULE III programme. The purpose is to give architects and contracting authorities a multimedia tool to enable them to simultaneously grasp the whole process of apartment building refurbishment or retrofit. It has a number of functions: Assess the building`s degradation state based on a technical diagnosis after a standardised and complete inspection of the building; Prepare work proposals. These take into account not only the renovation of the building but also the improvement of the energy performance and IEQ; Estimate the costs corresponding to these works. A data base, containing the costs of 800 refurbishment works, provides a fast estimate of the total amount of the works being considered; Estimate the evolution of the degradation of the components if none of the works were to be carried out, as well as the refurbishment costs which would result. This paper provides an overview of the EPIQR methodology and the final deliverables of the project. (au)

  9. Point Lepreau refurbishment: plant condition assessment

    International Nuclear Information System (INIS)

    Allen, P.J.; Soulard, M.R.; David, F.; Clefton, G.; Weeks, R.

    2001-01-01

    New Brunswick Power (NB Power) has initiated a study into the refurbishment of the Point Lepreau Generating Station, with the objective to extend plant operation another 25 to 30 years. The end product of this study will be a business case that compares the costs of refurbishing Point Lepreau with costs of alternate means of generation. The Project Execution Plan and business case are being developed by an integrated team of AECL, NB Power and subcontractor staff under the project management of AECL. The refurbishment scope will include replacement of the pressure tubes, calandria tubes and part of the feeder piping. Planning of these replacements is part of the refurbishment study work. Planning is also underway for the environmental, safety and licensing issues that would need to be addressed to ensure future operation of the unit. In addition to these studies, a systematic review of the plant has been carried out to determine what other equipment refurbishment or replacement will be required due to ageing or obsolescence of plant equipment. This Plant Condition Assessment (PCA) follows a highly structured approach to ensure consistency. This paper presents an overview of the engineering process and the main findings from the work. (author)

  10. Barrier Coatings for Refractory Metals and Superalloys

    International Nuclear Information System (INIS)

    SM Sabol; BT Randall; JD Edington; CJ Larkin; BJ Close

    2006-01-01

    In the closed working fluid loop of the proposed Prometheus space nuclear power plant (SNPP), there is the potential for reaction of core and plant structural materials with gas phase impurities and gas phase transport of interstitial elements between superalloy and refractory metal alloy components during service. Primary concerns are surface oxidation, interstitial embrittlement of refractory metals and decarburization of superalloys. In parallel with kinetic investigations, this letter evaluates the ability of potential coatings to prevent or impede communication between reactor and plant components. Key coating requirements are identified and current technology coating materials are reviewed relative to these requirements. Candidate coatings are identified for future evaluation based on current knowledge of design parameters and anticipated environment. Coatings were identified for superalloys and refractory metals to provide diffusion barriers to interstitial transport and act as reactive barriers to potential oxidation. Due to their high stability at low oxygen potential, alumina formers are most promising for oxidation protection given the anticipated coolant gas chemistry. A sublayer of iridium is recommended to provide inherent diffusion resistance to interstitials. Based on specific base metal selection, a thin film substrate--coating interdiffusion barrier layer may be necessary to meet mission life

  11. Barrier Coatings for Refractory Metals and Superalloys

    Energy Technology Data Exchange (ETDEWEB)

    SM Sabol; BT Randall; JD Edington; CJ Larkin; BJ Close

    2006-02-23

    In the closed working fluid loop of the proposed Prometheus space nuclear power plant (SNPP), there is the potential for reaction of core and plant structural materials with gas phase impurities and gas phase transport of interstitial elements between superalloy and refractory metal alloy components during service. Primary concerns are surface oxidation, interstitial embrittlement of refractory metals and decarburization of superalloys. In parallel with kinetic investigations, this letter evaluates the ability of potential coatings to prevent or impede communication between reactor and plant components. Key coating requirements are identified and current technology coating materials are reviewed relative to these requirements. Candidate coatings are identified for future evaluation based on current knowledge of design parameters and anticipated environment. Coatings were identified for superalloys and refractory metals to provide diffusion barriers to interstitial transport and act as reactive barriers to potential oxidation. Due to their high stability at low oxygen potential, alumina formers are most promising for oxidation protection given the anticipated coolant gas chemistry. A sublayer of iridium is recommended to provide inherent diffusion resistance to interstitials. Based on specific base metal selection, a thin film substrate--coating interdiffusion barrier layer may be necessary to meet mission life.

  12. Introduction to superalloys

    International Nuclear Information System (INIS)

    Li-Chenggong

    1995-01-01

    Throughout history, humans have developed mechanical devices to satisfy their needs, Jet aircraft was thrust into public awareness with the 1937 flight of Hans Von Ohains turbine engine Heinkel in Germany and an independent development, the 1939 flight of Whittle's engine in England. Since that time, progress in jet propulsion and industrial gas turbines has been a growing engineering technology of immense importance. This opened a new era of engineering material called superalloy. Superalloy is an alloy developed for elevated temperature service usually based on group VIIA elements, where relatively severe mechanical stressing is encountered, and where high surface stability is frequently required. The title of the speech is T he Effect of a Changing Environment on the requirements of Engine Materials . In this speech, the author emphasized that may changes in the business environment have occurred in recent years, the aircraft engine business is rapidly changing from a military focus to a commercial one, speed to market will assume greater importance in the engine industry, and greater attention to customer value will be required to remain competitive etc. However the superalloys will continue to be developed in the future. (author) 14 figs

  13. Reactor refurbishment options for a changing climate

    Energy Technology Data Exchange (ETDEWEB)

    McNeish, D. [Bruce Power, Tiverton, Ontario (Canada)

    2012-07-01

    As the industry looks ahead to another generation of reactor refurbishment, it is acknowledged that the traditional way of Retubing a reactor is a daunting prospect for our investors and stakeholders. Innovations are required to mitigate the long downtime and large one-time investment associated with previous reactor refurbishments. These can take the shape of improvements to the Retube processes or by fundamentally changing the approach, e.g., calandria/shield tank replacement or partial Retubes. This session presents technical challenges that utilities need help resolving to arrive at a more attractive reactor refurbishment model. This includes issues related to calandria vessel fitness-for-service, the fuel channel replacement process, the feeder replacement process, life extension of fuel channels and feeders and complexities involving interfacing systems. (author)

  14. Reactor refurbishment options for a changing climate

    International Nuclear Information System (INIS)

    McNeish, D.

    2012-01-01

    As the industry looks ahead to another generation of reactor refurbishment, it is acknowledged that the traditional way of Retubing a reactor is a daunting prospect for our investors and stakeholders. Innovations are required to mitigate the long downtime and large one-time investment associated with previous reactor refurbishments. These can take the shape of improvements to the Retube processes or by fundamentally changing the approach, e.g., calandria/shield tank replacement or partial Retubes. This session presents technical challenges that utilities need help resolving to arrive at a more attractive reactor refurbishment model. This includes issues related to calandria vessel fitness-for-service, the fuel channel replacement process, the feeder replacement process, life extension of fuel channels and feeders and complexities involving interfacing systems. (author)

  15. Status of the BR2 refurbishment programme

    International Nuclear Information System (INIS)

    Koonen, E.

    1995-01-01

    The operation of the BR2 reactor with its second beryllium matrix is foreseen up to mid-1995. A refurbishment programme has been established in order to allow for future operation during at least ten years. Recently a positive decision to effectively carry out this programme has been taken. The refurbishment action plan follows from a general assessment of the different systems of BR2, with respect to their actual status, the operational experience and the evolution of safety standards and criteria. Ageing considerations were of uppermost importance in those assessments, not only to assure safety of future operation, but also to guarantee future availability and reliability. (orig.)

  16. Reactor protection system refurbishment at Paks

    International Nuclear Information System (INIS)

    Hetzmann, A.; Turi, T.

    1997-01-01

    The history and the milestones of the reactor protection system refurbishment are outlined. During the preparation phase of the refurbishment project, detailed requirements have been set up and specific technical solutions developed. The structure of the project documents prepared during these activities is shown in a figure. The life cycle of the project was divided into four phases: the preparatory phase; the design and manufacturing phase; the installation and commissioning phase; and the operation phase. For all four Paks units a time schedule for implementation was set up. The licensing process is dealt with; the principal license was issued in June 1996. (A.K.)

  17. Ion beam analysis of gas turbine blades: evaluation of refurbishment ...

    Indian Academy of Sciences (India)

    Scanning proton microscopy was employed to evaluate the quality of refurbishment process of gas turbine ... environment of hot combustion gases occur due to various processes, such as .... performance of refurbished blades.7. Due to the ...

  18. Refurbishing the BR2 materials testing reactor

    International Nuclear Information System (INIS)

    Baugnet, J.M.; Dekeyser, J.; Gubel, P.

    1995-01-01

    SCK/CEN is refurbishing its BR2 reactor to allow its further operation during the next 15 years; in doing so, it chooses to keep BR2 available for future scientific and technological irradiation programs within an international context. (author) 2 figs

  19. Evaluation methodology for generator refurbishment decisions

    International Nuclear Information System (INIS)

    Moore, W.G.; Ulm, S.F.

    1991-01-01

    The Electrical Power Industry is undergoing tremendous change due to deregulation, aging equipment, environmental concerns, and investment/risk considerations. Public utility commissions, along with shareholders and end consumers, are closely monitoring utilities; decisions, especially in the area of costs-both Operation and Maintenance, and Capital. Increasing emphasis, within the conventional utility environment, has been and continue to be, placed on controlling expenditures. To be responsive to these industry and competitive pressures, utilities must make equipment refurbishment decisions. These decisions should be based on input from many sources, including the severity of the failure, cost of replacement versus refurbishment, risks and safety considerations, the expected remaining life of the unit, operational mode (base or peak), fuel type, initial costs, system capacity, available budgets, and financing options. Many times, however, refurbishment decisions are base don an abstract understanding of the above, but feel, or emotional attachment to a particular option. This paper describes a general methodology for refurbishment decision making, applied specifically to generators. Also included in a case history of one utility's progression through this process

  20. System impact of energy efficient building refurbishment within a district heated region

    International Nuclear Information System (INIS)

    Lidberg, T.; Olofsson, T.; Trygg, L.

    2016-01-01

    The energy efficiency of the European building stock needs to be increased in order to fulfill the climate goals of the European Union. To be able to evaluate the impact of energy efficient refurbishment in matters of greenhouse gas emissions, it is necessary to apply a system perspective where not only the building but also the surrounding energy system is taken into consideration. This study examines the impact that energy efficient refurbishment of multi-family buildings has on the district heating and the electricity production. It also investigates the impact on electricity utilization and emissions of greenhouse gases. The results from the simulation of four energy efficiency building refurbishment packages were used to evaluate the impact on the district heating system. The packages were chosen to show the difference between refurbishment actions that increase the use of electricity when lowering the heat demand, and actions that lower the heat demand without increasing the electricity use. The energy system cost optimization modeling tool MODEST (Model for Optimization of Dynamic Energy Systems with Time-Dependent Components and Boundary Conditions) was used. When comparing two refurbishment packages with the same annual district heating use, this study shows that a package including changes in the building envelope decreases the greenhouse gas emissions more than a package including ventilation measures. - Highlights: • Choice of building refurbishment measures leads to differences in system impact. • Building refurbishment in district heating systems reduces co-produced electricity. • Valuing biomass as a limited resource is crucial when assessing global GHG impact. • Building envelope measures decrease GHG (greenhouse gas) emissions more than ventilation measures.

  1. The Role of Laser Additive Manufacturing Methods of Metals in Repair, Refurbishment and Remanufacturing - Enabling Circular Economy

    Science.gov (United States)

    Leino, Maija; Pekkarinen, Joonas; Soukka, Risto

    Circular economy is an economy model where products, components, and materials are aimed to be kept at their highest utility and value at all times. Repair, refurbishment and remanufacturing processes are procedures aiming at returning the value of the product during its life cycle. Additive manufacturing (AM) is expected to be an enabling technology in circular economy based business models. One of AM process that enables repair, refurbishment and remanufacturing is Directed Energy Deposition. Respectively Powder Bed Fusion enables manufacturing of replacement components on demand. The aim of this study is to identify the current research findings and state of art of utilizing AM in repair, refurbishment and remanufacturing processes of metallic products. The focus is in identifying possibilities of AM in promotion of circular economy and expected environmental benefits based on the found literature. Results of the study indicate significant potential in utilizing AM in repair, refurbishment and remanufacturing activities.

  2. Refurbishing of a Freeze Drying Machine, used in Nuclear Medicine for Radiopharmaceuticals Production

    International Nuclear Information System (INIS)

    Gaytan-Gallardo, E.; Desales-Galeana, G.

    2006-01-01

    The refurbishing of a freeze drying machine used in the radiopharmaceuticals production, applied in nuclear medicine in the Radioactive Materials Department of the Nuclear Research National Institute in Mexico (ININ in Spanish), is presented. The freeze drying machine was acquired in the 80's decade and some components started having problems. Then it was necessary to refurbish this equipment by changing old cam-type temperature controllers and outdated recording devices, developing a sophisticated software system that substitutes those devices. The system is composed by a freeze drying machine by Hull, AC output modules for improved temperature control, a commercial data acquisition card, and the software system

  3. Structural radioactive waste from 'retubing/refurbishment' of Embalse nuclear power plant. Regulatory perspective

    International Nuclear Information System (INIS)

    Alvarez, Daniela E.; Lee Gonzales, Horacio M.; Medici, Marcela A.; Piumetti, Elsa H.

    2009-01-01

    Unlike the building of a new nuclear reactor, the 'retubing / refurbishment' of nuclear reactors that have been in operation for many years, involves the replacement of components in a radioactive environment. This requires a carefully planned radiation protection program to ensure protection of workers, the public and the environment as well as a radioactive waste management program for those radioactive waste generated during the process, which go beyond those generated during the normal operation and maintenance of the plant. Nucleoelectrica Argentina Sociedad Anonima (NA-SA) is scheduled to conduct the Life Extension Process of Embalse Nuclear Power Plant (CNE) which essentially consist of 'retubing / refurbishment' of the installation. The Nuclear Regulatory Authority (ARN) will then have an important activity related to the above process. In particular, this paper will describe some points of interest related to the generation and management of radioactive waste during the 'retubing / refurbishment' of the CNE, from the regulatory point of view. (author)

  4. Extended layup of steam generators during a refurbishment outage

    International Nuclear Information System (INIS)

    Marks, C.R.; Little, M.D.; Slade, J.; Gendron, T.

    2009-01-01

    In May 2008, Point Lepreau Generating Station (PLGS), owned and operated by New Brunswick Power Nuclear (NBPN), entered an extended refurbishment outage initially expected to last approximately 18 months. NBPN had the two inter-related goals with respect to layup of the steam generators during this period: equipment preservation and inspection interval modification. The steam generators were to be preserved such that there was no loss of operating life due to corrosion of either the tubing (Alloy 800NG) or other internal components (with carbon steel being the limiting material with respect to corrosion). Additionally, NBPN desired that the time in layup not count as operating time in setting the schedule for future inspections. That is, a key goal of the steam generator layup is that the future inspection interval be based on operating time, not calendar time. The NBPN approach consists of the following four steps: A review of industry operating experience with long outages (including both PWRs and PHWRs); The development of technically based layup strategies and procedures; A mid-outage review of the implementation of the layup strategies and procedures; and A post-outage review to determine if the actual conditions in the steam generators will support modification of the inspection interval. This paper discusses the results of the first three of these steps. At this time, the plant is still in the refurbishment outage. Throughout the outage evaluation process, the following issues have been the main focus of the reviews: The potential for degradation (pitting and cracking) of steam generator tubes; The potential for general corrosion of carbon and low alloy steel internals; Oxidation of deposits (which could subsequently lead to oxidizing conditions during operation, possibly leading to tube degradation). This paper discusses the industry operating experience reviewed, the pre-outage assessments, and the mid-outage assessments. Current outage planning places the

  5. Refurbishment of the regulating and control equipment, Task 3.08/04-05

    International Nuclear Information System (INIS)

    Nikolic, M.; Popovic, B.

    1963-01-01

    In addition to the planned refurbishment and maintenance of the RA reactor control and regulating systems, this report describes the maintenance of the reactor protection and safety systems. According to the instructions included in this report the components of these systems were tested to verify their reliability

  6. Water electrolysis system refurbishment and testing

    Science.gov (United States)

    Greenough, B. M.

    1972-01-01

    The electrolytic oxygen generator for the back-up water electrolysis system in a 90-day manned test was refurbished, improved and subjected to a 182-day bench test. The performance of the system during the test demonstrated the soundness of the basic electrolysis concept, the high development status of the automatic controls which allowed completely hands-off operation, and the capability for orbital operation. Some design improvements are indicated.

  7. Refurbishment of the IEAR1 primary coolant system piping supports

    International Nuclear Information System (INIS)

    Fainer, Gerson; Faloppa, Altair A.; Oliveira, Carlos A. de; Mattar Neto, Miguel

    2015-01-01

    A partial replacement of the IEA-R1 piping system was concluded in 2014. This paper presents the study and the structural analysis of the IEA-R1 primary circuit piping supports, considering all the changes involved in the replacement. The IEA-R1 is a nuclear reactor for research purposes designed by Babcox-Willcox that is operated by IPEN since 1957. The reactor life management and modernization program is being conducted for the last two decades and already resulted in a series of changes, especially on the reactor coolant system. This set of components, divided in primary and secondary circuit, is responsible for the circulation of water into the core to remove heat. In the ageing management program that includes regular inspection, some degradation was observed in the primary piping system. As result, the renewing of the piping system was conducted in 2014. Moreover the poor condition of some original piping supports gave rise to the refurbishment of all piping supports. The aim of the present work is to review the design of the primary system piping supports taking into account the current conditions after the changes and refurbishment. (author)

  8. Refurbishment of the reactor protection system at Paks NPP. The refurbishment process

    International Nuclear Information System (INIS)

    Turi, T.; Katics, B.

    1998-01-01

    The Reactor Protection System Refurbishment Project had an extensive preparation period in Paks started in 1992. During this preparation a large volume of the basic engineering tasks has been performed and as a result a contract for implementation of a three-train digital RPS on the four Units was concluded with Siemens in September, 1996. According to that contract the first refurbished Unit will be commissioned in 1999 followed by a further Unit in each succeeding year. This paper introduces the process of the refurbishment, overview of the V and V activities, introduce the architecture, summarize the main design principles and outlines the additional tasks to be performed together with the RPS design. (author)

  9. Innovative technologies for powder metallurgy-based disk superalloys: Progress and proposal

    Science.gov (United States)

    Chong-Lin, Jia; Chang-Chun, Ge; Qing-Zhi, Yan

    2016-02-01

    Powder metallurgy (PM) superalloys are an important class of high temperature structural materials, key to the rotating components of aero engines. In the purview of the present challenges associated with PM superalloys, two novel approaches namely, powder preparation and the innovative spray-forming technique (for making turbine disk) are proposed and studied. Subsequently, advanced technologies like electrode-induction-melting gas atomization (EIGA), and spark-plasma discharge spheroidization (SPDS) are introduced, for ceramic-free superalloy powders. Presently, new processing routes are sought after for preparing finer and cleaner raw powders for disk superalloys. The progress of research in spray-formed PM superalloys is first summarized in detail. The spray-formed superalloy disks specifically exhibit excellent mechanical properties. This paper reviews the recent progress in innovative technologies for PM superalloys, with an emphasis on new ideas and approaches, central to the innovation driving techniques like powder processing and spray forming. Project supported by the National Natural Science Foundation of China (Grant Nos. 50974016 and 50071014).

  10. Welding and Weldability of Directionally Solidified Single Crystal Nickel-Base Superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Vitek, J M; David, S A; Reed, R W; Burke, M A; Fitzgerald, T J

    1997-09-01

    Nickel-base superalloys are used extensively in high-temperature service applications, and in particular, in components of turbine engines. To improve high-temperature creep properties, these alloys are often used in the directionally-solidified or single-crystal form. The objective of this CRADA project was to investigate the weldability of both experimental and commercial nickel-base superalloys in polycrystalline, directionally-solidified, and single-crystal forms.

  11. Evaluation of three refurbished Guralp CMG-3TB seismometers.

    Energy Technology Data Exchange (ETDEWEB)

    Hart, Darren M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Merchant, Bion J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-05-01

    The overall objective of testing the Guralp CMG-3TB refurbished seismometers is to determine whether or not the refurbished sensors exhibit better data quality and require less maintenance when deployed than the original Guralp CMG-3TBs. SNL will test these 3 refurbished Guralps to verify performance specifications. The specifications that will be evaluated are sensitivity, bandwidth, self-noise, output impedance, clip-level, dynamic range over application passband, verify mathematical response and calibration response parameters for amplitude and phase.

  12. Refurbishment of BR2 (Phases 4 and 5)

    International Nuclear Information System (INIS)

    Gubel, P.; Dekeyser, J.; Van Der Auwera, J.

    1998-01-01

    The BR2 is a materials testing reactor and is SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In phase 4 of the refurbishment programme, various activities were performed to allow reactor start-up. In phase 5, remaining refurbishment works were carried out as well as the extra studies and upgradings required by the licensing authorities. Major achievements in 1997 are described and discussed

  13. Refurbishment of BR2 (Phases 4 and 5)

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P; Dekeyser, J; Van Der Auwera, J

    1998-07-01

    The BR2 is a materials testing reactor and is SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In phase 4 of the refurbishment programme, various activities were performed to allow reactor start-up. In phase 5, remaining refurbishment works were carried out as well as the extra studies and upgradings required by the licensing authorities. Major achievements in 1997 are described and discussed.

  14. Basic policy of JMTR refurbishment and regulatory procedure

    International Nuclear Information System (INIS)

    Tobita, Kenji

    2012-04-01

    The JMTR refurbishment started from FY2007 had been completed on the end of the FY2010. The refurbishment works carried out on about 60 items nuclear reactor systems, (about 40 of facilities and about 20 constructions) with no trouble. This report review the basic policy of JMTR refurbishment, such as a selection of facilities/equipments for the refurbishment and the determination method of specifications for repairs. The deliberation and discussion by the safety review committee of Oarai Research and Development Center in the Japan Atomic Energy Agency and nuclear regulatory procedure are included in this report. (author)

  15. Refurbishing Fæstningens Materialgård

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2014-01-01

    upgrading and refurbishment of the individual buildings that make up the listed complex. The process focuses on the cooperation and dialogue between the parties involved. Fæstningens Materialgård is a case study where the Heritage Agency, the Danish Working Environment Authority and the owner as a team...... cooperated in identifying feasible refurbishment measures. Through the process the owner was supported by architects and engineers. Focus is put on how, to identify potential energy savings and, to decide on energy upgrading measures when refurbishing and restoring listed buildings. The refurbished...

  16. Refurbishment programme for the BR2-reactor

    Energy Technology Data Exchange (ETDEWEB)

    Koonen, E [Centre d' Etude de l' Energie Nucleaire, Studiecentrum voor Kernenergie, BR2 Department, Boeretang, Mol (Belgium)

    1992-07-01

    BR2 is a high flux engineering test reactor, which differs from comparable material testing reactors by its specific core array (fig. 1). It is a heterogeneous, thermal, tank-in-pool type reactor, moderated by beryllium and light water, which serves also as coolant. The fuel elements consist of cylindrical assemblies loaded in channels materialized by hexagonal beryllium prisms. The central 200 mm channel is vertical, while all others are inclined and form a hyperbolical arrangement around the central one. This feature combines a very compact core with the requirement of sufficient space for individual access to all channels through penetrations in the top cover of the aluminium pressure vessel. Each channel may hold a fuel element, a control rod, an experiment, an irradiation device or a beryllium plug. The refurbishment Program According to the present programme of C.E.N./S.C.K., BR2 will be in operation until 1996. At that time, the beryllium matrix will reach its foreseen end-of-life. In order to continue operation beyond this point, a thorough refurbishment of the reactor is foreseen, in addition to the unavoidable replacement of the matrix, to ensure quality of the installation and compliance with modern standards. Some fundamental options have been taken as a starting point: BR2 will continue to be used as a classical MTR, i.e. fuel and material irradiations and safety experiments with some additional service-activities. The present configuration is optimized for that use and there is no specific experimental requirement to change the basic concepts and performance characteristics. From the customers viewpoint, it is desirable to go ahead with the well-known features of BR2, to maintain a high degree of availability and reliability and to minimize the duration of the long shutdown. It is also important to limit the amount of nuclear liabilities. So the objective of the refurbishment programme is the life extension of BR2 for about 15 years, corresponding to

  17. Refurbishment programme for the BR2-reactor

    International Nuclear Information System (INIS)

    Koonen, E.

    1992-01-01

    BR2 is a high flux engineering test reactor, which differs from comparable material testing reactors by its specific core array (fig. 1). It is a heterogeneous, thermal, tank-in-pool type reactor, moderated by beryllium and light water, which serves also as coolant. The fuel elements consist of cylindrical assemblies loaded in channels materialized by hexagonal beryllium prisms. The central 200 mm channel is vertical, while all others are inclined and form a hyperbolical arrangement around the central one. This feature combines a very compact core with the requirement of sufficient space for individual access to all channels through penetrations in the top cover of the aluminium pressure vessel. Each channel may hold a fuel element, a control rod, an experiment, an irradiation device or a beryllium plug. The refurbishment Program According to the present programme of C.E.N./S.C.K., BR2 will be in operation until 1996. At that time, the beryllium matrix will reach its foreseen end-of-life. In order to continue operation beyond this point, a thorough refurbishment of the reactor is foreseen, in addition to the unavoidable replacement of the matrix, to ensure quality of the installation and compliance with modern standards. Some fundamental options have been taken as a starting point: BR2 will continue to be used as a classical MTR, i.e. fuel and material irradiations and safety experiments with some additional service-activities. The present configuration is optimized for that use and there is no specific experimental requirement to change the basic concepts and performance characteristics. From the customers viewpoint, it is desirable to go ahead with the well-known features of BR2, to maintain a high degree of availability and reliability and to minimize the duration of the long shutdown. It is also important to limit the amount of nuclear liabilities. So the objective of the refurbishment programme is the life extension of BR2 for about 15 years, corresponding to

  18. Utility-vendor partnerships for refurbishment projects

    Energy Technology Data Exchange (ETDEWEB)

    Newman, G.; Hall, H. [Bruce Power, Tiverton, Ontario (Canada)

    2012-07-01

    Through the course of normal operation of the six (6) Bruce Power units, the quality of plant modifications has from time to time resulted in extensive rework, additional cost and significant unit generation schedule delays. This has impacted Bruce Power’s ability to successfully deliver our capital improvement program, generation plan and therefore our business plan. More recently, the restart of Units 1 and 2 have exhibited this same issue however in a more intensive manner due to the large number of Structures, Systems and Components (SSC) being brought into service. As such Bruce Power has and will continue to take steps to bolster its Quality Assurance and Control provisions as necessary to ensure that upgrades to our stations work first time and every time. Part of this enhanced focus involves the upfront Engineering Change Control (ECC) process and from this perspective it is imperative that these modifications meet and/or exceed the provisions within the Bruce Power ECC requirements, including the quality gates associated with the key milestones within this protocol. As such Bruce Power has and will continue to hold training sessions with our key Vendors to ensure that these requirements are clear since this shall determine the nature of our future working relationship. For Vendors who adhere to these requirements, support will continue to be requested and for cases where they do not, services will be suspended. By extension, services provided in support of field work will similarly be monitored and screened with the same objective, high quality installations must become the standard rather than the exception and special steps have identified and are being implemented to improve the performance in this area of our business. In aggregate the above theme is consistent with a continuous improvement perspective and in recognition that not all services provided by our current Vendor base are of equivalent quality. Bruce Power understands that we must work

  19. Utility-vendor partnerships for refurbishment projects

    International Nuclear Information System (INIS)

    Newman, G.; Hall, H.

    2012-01-01

    Through the course of normal operation of the six (6) Bruce Power units, the quality of plant modifications has from time to time resulted in extensive rework, additional cost and significant unit generation schedule delays. This has impacted Bruce Power’s ability to successfully deliver our capital improvement program, generation plan and therefore our business plan. More recently, the restart of Units 1 and 2 have exhibited this same issue however in a more intensive manner due to the large number of Structures, Systems and Components (SSC) being brought into service. As such Bruce Power has and will continue to take steps to bolster its Quality Assurance and Control provisions as necessary to ensure that upgrades to our stations work first time and every time. Part of this enhanced focus involves the upfront Engineering Change Control (ECC) process and from this perspective it is imperative that these modifications meet and/or exceed the provisions within the Bruce Power ECC requirements, including the quality gates associated with the key milestones within this protocol. As such Bruce Power has and will continue to hold training sessions with our key Vendors to ensure that these requirements are clear since this shall determine the nature of our future working relationship. For Vendors who adhere to these requirements, support will continue to be requested and for cases where they do not, services will be suspended. By extension, services provided in support of field work will similarly be monitored and screened with the same objective, high quality installations must become the standard rather than the exception and special steps have identified and are being implemented to improve the performance in this area of our business. In aggregate the above theme is consistent with a continuous improvement perspective and in recognition that not all services provided by our current Vendor base are of equivalent quality. Bruce Power understands that we must work

  20. Development of a virtual training simulator for a challenging refurbishment task

    International Nuclear Information System (INIS)

    Mort, P.E.

    1996-01-01

    An overview is presented of the technology, developed by British Nuclear Fuels Limited (BNFL), to create a virtual training simulator for refurbishment tasks. It focuses on the Raffinate Project, a challenging plant modification take, performed remotely, during which component removal, welding and installation of new components are all undertaken. The Training Simulator developed required fast multiprocessor computing with system intercommunication. Operators responded well to the Training Simulator and further improvements to the system are underway. (UK)

  1. Mechanical behavior of superalloys

    International Nuclear Information System (INIS)

    Floreen, S.

    1986-04-01

    Recent developments affecting the mechanical behavior of superalloys over three ranges of operating temperatures are reviewed. At lower temperatures, activity has been focused on stress corrosion cracking susceptibility in light water reactor and sour gas well environments. The susceptibility to intergranular crack growth is critically dependent upon the grain boundary chemistry, and a method of minimizing the sensitivity of the boundaries to attack has been pursued. At intermediate temperatures, considerable effort has been directed toward increasing the tensile and fatigue strengths. The higher strength materials, however, show increased fracture sensitivity. In particular, embrittlement due to diffusion into the grain boundaries of aggressive species, such as oxygen or sulfur from the environments, becomes a problem. Minor element alloying additions of boron, zirconium, magnesium, etc., are helpful in retarding the degradation caused by the environment. At higher temperatures, the major thrust is toward improving the creep strength. The weak link in the materials, which is the transverse grain boundaries, has been eliminated by the use of specialized processing steps to produce either directionally solidified materials with minimum transverse grain boundaries, or single crystal materials. Single crystal materials permit alloying and heat treating modifications that further enhance the creep strength. The materials are very anisotropic in properties, but are successfully used in turbine blades and could be useful in other special applications

  2. Creep properties of heat-resistant superalloys for nuclear plants in helium

    International Nuclear Information System (INIS)

    Shimizu, Shigeki; Satoh, Keisuke; Honda, Yoshio; Matsuda, Shozo; Murase, Hirokazu

    1979-01-01

    Creep properties of candidate superalloys for VHTR components in a helium environment at both temperatures of 800 0 C and 900 0 C were compared with those of the same alloys in the atmospheric condition, and the superalloys were contrasted with each other from the viewpoint of high temperature structural design. At 800 0 C, no significant effect of a helium environment on creep properties of the superalloys is observed. At 900 0 C, however, creep strength of Inconel 617, Incoloy 800 and Incoloy 807 in the helium environment decrease more than in the atmospheric environment. In Hastelloy X and Inconel 625, there is no significant difference between creep strengths in helium and those in the atmospheric condition. Concerning So and St values in helium at 900 0 C, Inconel 617 and Hastelloy X are clearly superior to other superalloys. (author)

  3. Refurbishment of the gas system, Task 3.08/04-07; Podzadatak 3.08/04-07 Remont sistema gasa

    Energy Technology Data Exchange (ETDEWEB)

    Nikolic, M; Bratic, A [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    During the period planned for maintenance and refurbishment of the RA reactor gas system in the RA reactor building was inspected and tested, the components were cleaned and decontaminated. This report describes detailed instructions and actions concerning repair and decontamination of the gas system components.

  4. Advanced instrumentation and control systems for CANDU refurbishment

    International Nuclear Information System (INIS)

    Sklyar, V.; Bakhmach, I.; Kharchenko, V.; Andrashov, A.; Baranova, O.

    2011-01-01

    The purpose of the work is to discuss opportunities to modernize I and C systems of CANDU reactors on the base of Radiy's digital safety platform. This paper discusses the following topics: a business model for CANDU, I and C systems refurbishment, FPGA technology issues, comparison of different approaches to refurbish obsolete I and C systems. (author)

  5. Expert systems for superalloy studies

    Science.gov (United States)

    Workman, Gary L.; Kaukler, William F.

    1990-01-01

    There are many areas in science and engineering which require knowledge of an extremely complex foundation of experimental results in order to design methodologies for developing new materials or products. Superalloys are an area which fit well into this discussion in the sense that they are complex combinations of elements which exhibit certain characteristics. Obviously the use of superalloys in high performance, high temperature systems such as the Space Shuttle Main Engine is of interest to NASA. The superalloy manufacturing process is complex and the implementation of an expert system within the design process requires some thought as to how and where it should be implemented. A major motivation is to develop a methodology to assist metallurgists in the design of superalloy materials using current expert systems technology. Hydrogen embrittlement is disasterous to rocket engines and the heuristics can be very complex. Attacking this problem as one module in the overall design process represents a significant step forward. In order to describe the objectives of the first phase implementation, the expert system was designated Hydrogen Environment Embrittlement Expert System (HEEES).

  6. Fatigue of superalloys and intermetallics

    International Nuclear Information System (INIS)

    Stoloff, N.S.

    1993-01-01

    The fatigue behavior of intermetallic alloys and their composites is contrasted to that of nickel-base superalloys. The roles of microstructure and slip planarity are emphasized. Obstacles to use of intermetallics under cyclic loading conditions are described and future research directions are suggested

  7. I and C systems refurbishment projects for plant life extension

    International Nuclear Information System (INIS)

    Andrashov, A.A.; Sklyar, V.V.; Siora, A.A.

    2012-01-01

    This paper describes the approach to implementation of Nuclear Power Plants (NPPs) Instrumentation and Control (I and C) systems refurbishment projects using Field Programmable Gate Array (FPGA)-based platform. The analysis identifying advantages of refurbishment projects for NPPs is performed. The main goals of the utilities with respect to refurbishment of NPPs I and C systems are outlined. The advantages of FPGA technology application for NPP I and C systems are described. Regulatory framework of FPGA technology for NPPs I and C systems is presented. General principles which may be used for implementation of NPPs I and C system refurbishment projects are presented. The experience of Research and Production Corporation (RPC) Radiy in implementation of NPPs I and C system refurbishment projects is considered. (author)

  8. Sustainable refurbishment of exterior walls and building facades. Final report, Part B - General refurbishment concepts

    Energy Technology Data Exchange (ETDEWEB)

    Vares, S.; Pulakka, S.; Toratti, T. [and others

    2012-11-01

    This report is the second part of the final report of Sustainable refurbishment of building facades and exterior walls (SUSREF). SUSREF project was a collaborative (small/medium size) research project within the 7th Framework Programme of the Commission and it was financed under the theme Environment (including climate change) (Grant agreement no. 226858). The project started in October 1st 2009 and ended in April 30th 2012. The project included 11 partners from five countries. SUSREF developed sustainable concepts and technologies for the refurbishment of building facades and external walls. This report together with SUSREF Final report Part B and SUSREF Final Report Part C introduce the main results of the project. Part A focuses on methodological issues. The descriptions of the concepts and the assessment results of the developed concepts are presented in SUSREF Final report part B (generic concepts) and SUSREF Final report Part C (SME concepts). The following list shows the sustainability assessment criteria defined by the SUSREF project. These are Durability; Impact on energy demand for heating; Impact on energy demand for cooling; Impact on renewable energy use potential; Impact on daylight; Environmental impact of manufacture and maintenance; Indoor air quality and acoustics; Structural stability; Fire safety; Aesthetic quality; Effect on cultural heritage; Life cycle costs; Need for care and maintenance; Disturbance to the tenants and to the site; Buildability. This report presents sustainability assessment results of general refurbishment concepts and gives recommendations on the basis of the results. The report covers the following refurbishment cases - External insulation - Internal insulation - Cavity wall insulation - Replacement Insulation during renovation.

  9. Soft Computing Methods in Design of Superalloys

    Science.gov (United States)

    Cios, K. J.; Berke, L.; Vary, A.; Sharma, S.

    1996-01-01

    Soft computing techniques of neural networks and genetic algorithms are used in the design of superalloys. The cyclic oxidation attack parameter K(sub a), generated from tests at NASA Lewis Research Center, is modelled as a function of the superalloy chemistry and test temperature using a neural network. This model is then used in conjunction with a genetic algorithm to obtain an optimized superalloy composition resulting in low K(sub a) values.

  10. Laser enabled refurbishment and performance enhancement of industrial components

    CSIR Research Space (South Africa)

    Van Rooyen, C

    2011-09-01

    Full Text Available is unavailable Thank you for your attention! ? CSIR 2006 www.csir.co.zaSlide 33 The Laser Materials Processing Competence area wishes to express their gratitude to: ? DST ? CSIR ?Fraunhofer ILT For enabling us to make LIGHT work...

  11. Mechanical Properties Experimental Study of Engineering Vehicle Refurbished Tire

    Science.gov (United States)

    Qiang, Wang; Xiaojie, Qi; Zhao, Yang; Yunlong, Wang; Guotian, Wang; Degang, Lv

    2018-05-01

    The vehicle refurbished tire test system was constructed, got load-deformation, load-stiffness, and load-compression ratio property laws of engineering vehicle refurbished tire under the working condition of static state and ground contact, and built radial direction loading deformation mathematics model of 26.5R25 engineering vehicle refurbished tire. The test results show that radial-direction and side-direction deformation value is a little less than that of the new tire. The radial-direction stiffness and compression ratio of engineering vehicle refurbished tire were greatly influenced by radial-direction load and air inflation pressure. When load was certain, radial-direction stiffness would increase with air inflation pressure increasing. When air inflation pressure was certain, compression ratio of engineering vehicle refurbished tire would enlarge with radial-direction load increasing, which was a little less than that of the new and the same type tire. Aging degree of old car-case would exert a great influence on deformation property of engineering vehicle refurbished tire, thus engineering vehicle refurbished tires are suitable to the working condition of low tire pressure and less load.

  12. Multivariant design and multiple criteria analysis of building refurbishments

    Energy Technology Data Exchange (ETDEWEB)

    Kaklauskas, A.; Zavadskas, E. K.; Raslanas, S. [Faculty of Civil Engineering, Vilnius Gediminas Technical University, Vilnius (Lithuania)

    2005-07-01

    In order to design and realize an efficient building refurbishment, it is necessary to carry out an exhaustive investigation of all solutions that form it. The efficiency level of the considered building's refurbishment depends on a great many of factors, including: cost of refurbishment, annual fuel economy after refurbishment, tentative pay-back time, harmfulness to health of the materials used, aesthetics, maintenance properties, functionality, comfort, sound insulation and longevity, etc. Solutions of an alternative character allow for a more rational and realistic assessment of economic, ecological, legislative, climatic, social and political conditions, traditions and for better the satisfaction of customer requirements. They also enable one to cut down on refurbishment costs. In carrying out the multivariant design and multiple criteria analysis of a building refurbishment much data was processed and evaluated. Feasible alternatives could be as many as 100,000. How to perform a multivariant design and multiple criteria analysis of alternate alternatives based on the enormous amount of information became the problem. Method of multivariant design and multiple criteria of a building refurbishment's analysis were developed by the authors to solve the above problems. In order to demonstrate the developed method, a practical example is presented in this paper. (author)

  13. Refurbishment of BR2 (Phases 4 and 5)

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P.; Dekeyser, J.; Van Der Auwera, J

    1998-07-01

    The BR2 is a materials testing reactor and is SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In phase 4 of the refurbishment programme, various activities were performed to allow reactor start-up. In phase 5, remaining refurbishment works were carried out as well as the extra studies and upgradings required by the licensing authorities. Major achievements in 1997 are described and discussed.

  14. Fatigue load considerations and use of high efficiency materials in the nuclear refurbishment projects: a structural engineering perspective

    Energy Technology Data Exchange (ETDEWEB)

    Mohee, F. M., E-mail: fmm_p@yahoo.com [Univ. of Waterloo, ON (Canada)

    2014-07-01

    For the Darlington refurbishment project in Canada, fatigue load consideration is a very crucial component in the analysis and design of different structures in the nuclear facilities. New and innovative structural materials having much higher ultimate tensile strength and modulus of elasticity, that are free from corrosion, should be considered along with fatigue load during the analysis and design of the nuclear refurbishment projects. The structural analysis should include beam, column and slabs, vibrating, rotating and crane supporting structures, robotic structures, pipe supports, Serapid chain and associated automated gate structures, flask supporting structures, processing unit and lidding unit support structures. (author)

  15. Microstructural Characterization and Modeling of SLM Superalloy 718

    Science.gov (United States)

    Smith, Tim M.; Sudbrack, Chantal K.; Bonacuse, Pete; Rogers, Richard

    2017-01-01

    Superalloy 718 is an excellent candidate for selective laser melting (SLM) fabrication due to a combination of excellent mechanical properties and workability. Predicting and validating the microstructure of SLM-fabricated Superalloy 718 after potential post heat-treatment paths is an important step towards producing components comparable to those made using conventional methods. At present, obtaining accurate volume fraction and size measurements of gamma-double-prime, gamma-prime and delta precipitates has been challenging due to their size, low volume fractions, and similar chemistries. A technique combining high resolution distortion corrected SEM imaging and with x-ray energy dispersive spectroscopy has been developed to accurately and independently measure the size and volume fractions of the three precipitates. These results were further validated using x-ray diffraction and phase extraction methods and compared to the precipitation kinetics predicted by PANDAT and JMatPro. Discrepancies are discussed in context of materials properties, model assumptions, sampling, and experimental errors.

  16. Systems engineering aspects to installation of the phased multi-year LANSCE-refurbishment project

    International Nuclear Information System (INIS)

    Pieck, Martin; Erickson, John E.; Gulley, Mark S.; Jones, Kevin W.; Rybarcyk, Larry J.

    2009-01-01

    The LANSCE Refurbishment Project (LANSCE-R) is a phased, multiyear project. The project is scheduled to start refurbishment in the 2nd quarter of fiscal year 2011. Closeout will occur during the 4th quarter of FY2016. During the LANSCE-R project, installation of project components must be scheduled during six annual 6-month maintenance-outages and not conflict with annual LANSCE operational commitments to its user facilities. The project and operations schedules must be synchronized carefully. Therefore, the scheduled maintenance outages, functional testing (with beam off, by primarily project personnel) and commissioning (with beam on, by primarily Accelerator Operation Technology (AOT) personnel) must be managed to accommodate operation. Active and effective coordination and communication between the project and AOT personnel must be encouraged to identify, as early as possible, any operational issues. This paper will report on the systems engineering approach to the integration and control of engineering activities.

  17. Modernization and refurbishment of the Central Interim Storage

    International Nuclear Information System (INIS)

    Mele, I.; Zeleznik, N.

    2002-01-01

    The Central Interim Storage for radioactive waste in Brinje, being put into operation in 1986, needs refurbishment and modernization in order to meet the up-to-date operational and safety requirements and to ensure the normal and undisturbed acceptance of radioactive waste from small producers in the future. Because of the waste, being already stored in the storage, the lack of reprocessing capacities and the lack of auxiliary room, the refurbishment and modernization is a complex problem, which needs to be addressed with care. The plan of refurbishment and modernization requires an integral approach, covering all different aspects of renewal and reconstruction. The implementation plan, however, must be based on the actual state of the storage and real conditions for the implementations: from technical to financial. In this paper the project for refurbishment and modernization of the storage, and some activities that have already been implemented, are presented.(author)

  18. Refurbishment of Railroad Crossties : A Technical and Economic Analysis

    Science.gov (United States)

    1977-12-01

    An analysis of the principal modes of failure for wooden railroad crossties was conducted and an evaluation of the technical and economic feasibility of refurbishing these ties was conducted. Among the principal modes of structural deterioration, onl...

  19. Refurbishment of BR2 (Phase 4 and 5)

    International Nuclear Information System (INIS)

    Gubel, P.; Dekeyser, J.; Van der Auwera, J.

    1998-01-01

    The extensive refurbishment of the BR-2 materials testing reactor should allow another 10 to 15 years of continued operation. The refurbishment programme is required in order to comply with modern safety standards, to enhance the reliability of operation, and to compensate for the ageing of the installations of a facility that has reached about 35 years of intensive service. The main objectives and achievements of phase 4 and 5 are described

  20. Simulated thermal energy demand and actual energy consumption in refurbished and non-refurbished buildings

    Science.gov (United States)

    Ilie, C. A.; Visa, I.; Duta, A.

    2016-08-01

    The EU legal frame imposes the Nearly Zero Energy Buildings (nZEB) status to any new public building starting with January 1st, 2019 and for any other new building starting with 2021. Basically, nZEB represents a Low Energy Building (LEB) that covers more than half of the energy demand by using renewable energy systems installed on or close to it. Thus, two steps have to be followed in developing nZEB: (1) reaching the LEB status through state- of-the art architectural and construction solutions (for the new buildings) or through refurbishing for the already existent buildings, followed by (2) implementing renewables; in Romania, over 65% of the energy demand in a building is directly linked to heating, domestic hot water (DHW), and - in certain areas - for cooling. Thus, effort should be directed to reduce the thermal energy demand to be further covered by using clean and affordable systems: solar- thermal systems, heat pumps, biomass, etc. or their hybrid combinations. Obviously this demand is influenced by the onsite climatic profile and by the building performance. An almost worst case scenario is approached in the paper, considering a community implemented in a mountain area, with cold and long winters and mild summers (Odorheiul Secuiesc city, Harghita county, Romania). Three representative types of buildings are analysed: multi-family households (in blocks of flats), single-family houses and administrative buildings. For the first two types, old and refurbished buildings were comparatively discussed.

  1. Major Refurbishment of the University of Florida Training Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Joradn, Kelly; Berglund, Matthew; Shea, Brian [Univ., of Florida, Florida (United States)

    2013-07-01

    The research reactor fleet is aging with few replacements being built. At the same time the technology for refurbishment of the older reactors has advanced well beyond that of currently installed equipment. The disparity between new and old technology results in an inability to find simple replacements for the older, highly integrated components. The lack of comprehensive guidance for digital equipment adds to the technical problems of installing individual replacement parts. Up to this point, no U. S. facilities have attempted a complete modernization effort because of the time commitment, financial burden, and licensing required for a total upgrade. The University of Florida Training Reactor is tackling this problem with a replacement of nearly all of the major facility sub-systems, including electrical distribution, reactor controls, nuclear instrumentation, security, building management, and environmental controls. This approach offers increased flexibility over the piece-by-piece replacement method by leveraging modern control systems based on global standards and capable of good data interchange with higher levels of redundancy. The UFTR reviewed numerous technologies to arrive at the final system architecture and this 'clean-slate' installation methodology. It is this concept of total system replacement and strict use of modular, open-standards technology that has allowed for a facility design that will be easy to install, maintain, and build upon over time.

  2. Major Refurbishment of the University of Florida Training Reactor

    International Nuclear Information System (INIS)

    Joradn, Kelly; Berglund, Matthew; Shea, Brian

    2013-01-01

    The research reactor fleet is aging with few replacements being built. At the same time the technology for refurbishment of the older reactors has advanced well beyond that of currently installed equipment. The disparity between new and old technology results in an inability to find simple replacements for the older, highly integrated components. The lack of comprehensive guidance for digital equipment adds to the technical problems of installing individual replacement parts. Up to this point, no U. S. facilities have attempted a complete modernization effort because of the time commitment, financial burden, and licensing required for a total upgrade. The University of Florida Training Reactor is tackling this problem with a replacement of nearly all of the major facility sub-systems, including electrical distribution, reactor controls, nuclear instrumentation, security, building management, and environmental controls. This approach offers increased flexibility over the piece-by-piece replacement method by leveraging modern control systems based on global standards and capable of good data interchange with higher levels of redundancy. The UFTR reviewed numerous technologies to arrive at the final system architecture and this 'clean-slate' installation methodology. It is this concept of total system replacement and strict use of modular, open-standards technology that has allowed for a facility design that will be easy to install, maintain, and build upon over time

  3. Refurbishment decision support tools review—Energy and life cycle as key aspects to sustainable refurbishment projects

    International Nuclear Information System (INIS)

    Ferreira, Joaquim; Pinheiro, Manuel Duarte; Brito, Jorge de

    2013-01-01

    Europe is facing one of its most challenging crises since Great Depression and the construction sector is one of the worst affected. Refurbishment is therefore often suggested as one of the most useful solutions for the current real estate crisis in consolidated areas like the EU. On the other hand, it is imperative to construct buildings according to sustainable principles regarding economic, environmental and social issues. Therefore, proper decision-support methods are needed to help designers, investors and policy makers to choose the most sustainable solution for a refurbishment project, especially for energy retrofit works. This paper reviews the works relating to sustainable refurbishment decision-support tools which have already been developed. For this purpose we have analysed and classified 40 different methods, with particular focus on their main common aims. They are also compared with other classifications proposed. This paper further highlights the role of energy as a driving factor and discusses what other research developments are needed to create related tools for the future that could respond to actual construction requirements. - Highlights: • Sustainable refurbishment as an important challenge. • Proper decision-support methods are needed to refurbishment. • The paper reviews 40 different methods, focusing their main common aims. • The paper highlights the role of the energy as key factor to search sustainability. • It also stresses the importance of life cycle approach in refurbishment projects

  4. Understanding valve program complexity in a refurbishment environment - learning from the past

    International Nuclear Information System (INIS)

    Roth, H.E.

    2012-01-01

    The complexity of Valve Program development, planning, execution and management in a refurbishment environment is an enormous undertaking requiring the proper coordination and integration of many moving parts. As such, lack of attention and understanding of this complexity has led to significant cost and schedule overruns in past refurbishment projects in the province. OPEX indicates the challenges in completing valve scope during refurbishments are related but not limited to; lack of detailed condition assessments, improper scope development, insignificant strategic approach to work task planning, scheduling and procurement, absence of contingency planning for common ‘as found’ conditions during execution, lack of proper training requirements, etc. In addition, past contracting strategies to employ numerous companies in collaboration to complete such a complex and specialized program, has resulted in further complications surrounding the management and integration of multiple quality programs and internal company processes. Finally, the aftermath of such fragmented projects results in an absolute closeout nightmare, often times taking years to locate, sift through and re-integrate pertinent information back into customer systems. Valve Program complexity cannot be understood by just anyone, only those that have lived through a refurbishment project and experienced the challenges mentioned above have the knowledge, skill, and ability to appreciate how to tactically apply past learning to realize future improvements. Furthermore, effective contractor-customer collaboration is crucial; true and in-depth knowledge and understanding of the customer quality programs, engineering and work management processes, configuration management requirements, and most importantly the imperative significance of nuclear safety, are all essential components to ensure overall alignment and program success. (author)

  5. Thermal protection and refurbishment of an old building. Lectures; Waermeschutz und Altbausanierung. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Within the 22nd Hanseatic Reconstruction Symposium at the Baltic Seaside Heringsdorf/Usedom (Federal Republic of Germany) from 3rd to 5th November 2011, the following lectures were held: (1) Energetic refurbishment possibilities for building within existing properties by means of representative examples (F. Deitschum); (2) Constructional thermal insulation and indoor climate - for the good of the environment? (S. Groer); (3) Innovative insulating materials for the structural refurbishment? (O. Fechner); (4) Energetic half-timbering refurbishment (K. Lissner); (5) Wooden solar facades for existing buildings (U. Schwarz); (6) Timber beam bowls in a historic brickwork (U. Mueller); (7) Timber beam bowls and interior insulation (U. Ruisinger); (8) Innovative solutions for cavity filling insulations (A. Stefenelli); (9) Thermal insulating plaster - also for historical buildings (T. Stahl); (10) Experimental tension analysis of the structural behaviour of historical cross vaults (A.-J. Petereit); (10) Investigation of the increase of the flexural strength of stonework constructions with self-compacting steel fibre reinforced concrete (D. Haessler); (11) Dry and dense - the modified WTA leaflet 4-6, 'Subsequent sealing of components in contact with soil' - Content and innovations (R. Spirgatis); (12) What does the new standard DIN 68800 hold? (H. Willeitner); (13) News from the standard DIN 18195 waterproofing of buildings (H.-P. Sommer); (14) Liability of planning of the offering entrepreneur (H. Immoor); (15) Climate change and preservation of structures (W. Zillig); (16) Typical problems and deficiencies of the energetic refurbishment of old store buildings (H. Boehmer); (17) When do ex post horizontal sealings with injection agents make sense - Fundamentals for evaluation, planning and execution (F.-J. Hoelzen); (18) Drying up behaviour of stonework of different quality and at different variants of insulation (F. Antretter).

  6. Understanding valve program complexity in a refurbishment environment - learning from the past

    Energy Technology Data Exchange (ETDEWEB)

    Roth, H.E. [Babcock & Wilcox Canada Ltd., Cambridge, Ontario (Canada)

    2012-07-01

    The complexity of Valve Program development, planning, execution and management in a refurbishment environment is an enormous undertaking requiring the proper coordination and integration of many moving parts. As such, lack of attention and understanding of this complexity has led to significant cost and schedule overruns in past refurbishment projects in the province. OPEX indicates the challenges in completing valve scope during refurbishments are related but not limited to; lack of detailed condition assessments, improper scope development, insignificant strategic approach to work task planning, scheduling and procurement, absence of contingency planning for common ‘as found’ conditions during execution, lack of proper training requirements, etc. In addition, past contracting strategies to employ numerous companies in collaboration to complete such a complex and specialized program, has resulted in further complications surrounding the management and integration of multiple quality programs and internal company processes. Finally, the aftermath of such fragmented projects results in an absolute closeout nightmare, often times taking years to locate, sift through and re-integrate pertinent information back into customer systems. Valve Program complexity cannot be understood by just anyone, only those that have lived through a refurbishment project and experienced the challenges mentioned above have the knowledge, skill, and ability to appreciate how to tactically apply past learning to realize future improvements. Furthermore, effective contractor-customer collaboration is crucial; true and in-depth knowledge and understanding of the customer quality programs, engineering and work management processes, configuration management requirements, and most importantly the imperative significance of nuclear safety, are all essential components to ensure overall alignment and program success. (author)

  7. Superalloy Lattice Block Developed for Use in Lightweight, High-Temperature Structures

    Science.gov (United States)

    Hebsur, Mohan G.; Whittenberger, J. Daniel; Krause, David L.

    2003-01-01

    Successful development of advanced gas turbine engines for aircraft will require lightweight, high-temperature components. Currently titanium-aluminum- (TiAl) based alloys are envisioned for such applications because of their lower density (4 g/cm3) in comparison to superalloys (8.5 g/cm3), which have been utilized for hot turbine engine parts for over 50 years. However, a recently developed concept (lattice block) by JAMCORP, Inc., of Willmington, Massachusetts, would allow lightweight, high-temperature structures to be directly fabricated from superalloys and, thus, take advantage of their well-known, characterized properties. In its simplest state, lattice block is composed of thin ligaments arranged in a three dimensional triangulated trusslike configuration that forms a structurally rigid panel. Because lattice block can be fabricated by casting, correctly sized hardware is produced with little or no machining; thus very low cost manufacturing is possible. Together, the NASA Glenn Research Center and JAMCORP have extended their lattice block methodology for lower melting materials, such as Al alloys, to demonstrate that investment casting of superalloy lattice block is possible. This effort required advances in lattice block pattern design and assembly, higher temperature mold materials and mold fabrication technology, and foundry practice suitable for superalloys (ref. 1). Lattice block panels have been cast from two different Ni-base superalloys: IN 718, which is the most commonly utilized superalloy and retains its strength up to 650 C; and MAR M247, which possesses excellent mechanical properties to at least 1100 C. In addition to the open-cell lattice block geometry, same-sized lattice block panels containing a thin (1-mm-thick) solid face on one side have also been cast from both superalloys. The elevated-temperature mechanical properties of the open cell and face-sheeted superalloy lattice block panels are currently being examined, and the

  8. Superalloy applications in the nuclear field

    International Nuclear Information System (INIS)

    Ramanathan, L.V.; Padilha, A.F.

    1984-01-01

    The process conditions in the areas of nuclear fuel processing, fabrication, utilization, reprocessing and disposal are severe, demanding therefore the use of materials with high temperature mechanical strength and corrosion resistance. A number of refractory metal containing superalloys have found application in the diferrent areas of the nuclear field. The main aspects of the microstructure, strengthening mechanisms and corrosion resistance of 3 superalloys, namely Incoloy 825, Inconel 718 and Hastelloy C have been discussed. The role of the refractory metal elements in influencing the mechanical strength and corrosion resistance of superalloys has been emphasised. (Author) [pt

  9. Loading Deformation Characteristic Simulation Study of Engineering Vehicle Refurbished Tire

    Science.gov (United States)

    Qiang, Wang; Xiaojie, Qi; Zhao, Yang; Yunlong, Wang; Guotian, Wang; Degang, Lv

    2018-05-01

    The paper constructed engineering vehicle refurbished tire computer geometry model, mechanics model, contact model, finite element analysis model, did simulation study on load-deformation property of engineering vehicle refurbished tire by comparing with that of the new and the same type tire, got load-deformation of engineering vehicle refurbished tire under the working condition of static state and ground contact. The analysis result shows that change rules of radial-direction deformation and side-direction deformation of engineering vehicle refurbished tire are close to that of the new tire, radial-direction and side-direction deformation value is a little less than that of the new tire. When air inflation pressure was certain, radial-direction deformation linear rule of engineer vehicle refurbished tire would increase with load adding, however, side-direction deformation showed linear change rule, when air inflation pressure was low; and it would show increase of non-linear change rule, when air inflation pressure was very high.

  10. Engineering study radioactive liquid waste treatment plant refurbishment

    International Nuclear Information System (INIS)

    Suazo, I.L.

    1994-01-01

    This feasibility study will investigate the opportunities, restrictions and cost impact to refurbish the existing Radioactive Liquid Waste Treatment Plant (RLWTP) while utilizing the same basic criteria that was used in the development of the new Radioactive Liquid Waste Treatment Facility (RLWTF). The objective of this study is to perform a more in-depth analysis of refurbishing the existing than has been done in the past so as to provide a basis for comparison between refurbishing the existing or constructing a new. The existing plant is located at Technical Area 50 (TA-50) within the Los Alamos National Laboratory (LANL). The initial structure was built in 1963. Over the ensuing years, the building has been modified and several additions have been constructed. In 1966, laboratories, ion exchange and pretreatment functions were added. The decontamination and decommissioning activities and ventilation equipment were added in 1984. The following assumptions are the basic parameters considered in the development of a design concept to refurbish the RLWTP: (1) Allow continued operation of the during retrofit construction. (2) Design the necessary expansion within the site constraints. (3) Satisfy National Pollutant Discharge Elimination System (NPDES) and National Emission Standards for Hazardous Air Pollutants (NESHAPS) permit conditions and other environmental regulations. (4) Comply with present DOE Orders and building code requirements. The refurbishment concept is a phased demolition and construction process

  11. Thermodynamic assessment of liquid composition change during solidification and its effect on freckle formation in superalloys

    International Nuclear Information System (INIS)

    Long Zhengdong; Liu Xingbo; Yang Wanhong; Chang, K.-M.; Barbero, Ever

    2004-01-01

    The solidification macrosegregation, i.e. freckle, becomes more and more concerned with ever increasing demand for the large ingot size of superalloys. The evaluation of freckle formation is very difficult because of the less understanding of freckle formation mechanism and complex solidification behaviors of multi-component superalloys. The macrostructure of typical Nb-bearing and Ti-bearing superalloys in horizontally directional solidification and vacuum arc remelting (VAR) ingots were investigated to clarify the freckle formation mechanism. The thermodynamic approach was proposed to simulate the solidification behaviors. The relative Ra numbers, a reliable criterion, of freckle formation for some alloys were obtained based on the results of thermodynamic calculations. This thermodynamic approach was evaluated through comparison of the calculations from semi-experimental results. The Ra numbers obtained by thermodynamic approach are in good agreement with the ingot size capability of the industry melting shops, which is limited mainly by freckle defects

  12. Steam generator life-management, reliability, maintenance and refurbishment

    International Nuclear Information System (INIS)

    Spekkens, P.

    2012-01-01

    SGC 2012 is a different kind of a conference - it has its own focus, initiatives and objectives and differs from its predecessors. It originated as the Steam Generator and Heat Exchanger Conference in 1990 - a time when premature degradation of steam generators with Alloy 600 tubes was rampant world-wide, and some CANDU steam generators had started to experience significant fouling and corrosion issues. The six previous steam generator conferences were held on a regular cycle, in a very similar format and with a similar theme. We are now in a different era in steam generators. The Alloy 600 tubing has been largely replaced by more robust materials, and the CANDU steam generators have been brought under much more intense and effective life cycle management. Performance of steam generators has improved greatly, and they are no longer considered at risk of limiting the life of the units. Indeed, most Incoloy 800 steam generators in CANDU units are considered to be capable of operating reliably through the 'second life' of the units and are not being replaced during refurbishments. Given this changing environment, the scope of this conference has been expanded from one to three areas: steam generators and heat exchangers as before, but also; controls, valves and pumps, and; reactor components and systems, Programs A, B and C, respectively. The conference is targeting to address the needs and interests of the operating utilities, and to 'focus on what needs attention'. As a means of 'focusing on what needs attention' an 'Issue-Identification and Definition' program was initiated last winter. The Issue-Identification Team operating with COG President Bob Morrison as its Executive Lead, worked to identify issues requiring attention in the three areas of interest. Of the many issues identified by the Team and elaborated on by the Program Developers of this conference, four were recommended for special attention: A. 'Operate Clean - Build Clean - Plant Wide': Despite their

  13. Refurbishment and safety upgradation of research reactor Cirus

    International Nuclear Information System (INIS)

    Marik, S.K.; Rao, D.V.H.; Bhatnagar, A.; Pant, R.C.; Tikku, A.C.; Sankar, S.

    2006-01-01

    Cirus, a 40 MW t, vertical tank type research reactor, having wide range of research facilities, was commissioned in the year 1960. This research reactor, situated at Mumbai, India has been operated and utilized extensively for isotope production, material testing and neutron beam research for nearly four decades. With a view to assess the residual life of the reactor, detailed ageing studies were carried out during the early 1990s. Based on these studies, refurbishment of Cirus for its life extension was taken up. During refurbishment, additional safety features were incorporated in various systems to qualify them for the current safety standards. This paper gives the details of the operating experiences, utilization of the reactor along with methodologies followed for carrying out detailed ageing studies, refurbishment and safety upgradation for its life extension

  14. Impact of flow accelerated corrosion (FAC) on feeder refurbishment planning

    International Nuclear Information System (INIS)

    Jyrkama, M.; Pandey, M.

    2010-01-01

    Feeder wall thinning due to flow accelerated corrosion (FAC) may result in a large number of feeder replacements in the future. In this study, the process of FAC is modelled using a probabilistic approach and used to predict the expected number of degraded feeders and their replacements in the future. Because of the high cost associated with feeder replacements, it may be optimal to replace the entire feeder population during a single refurbishment outage when the unit cost of replacement is likely to be less. The results of this study demonstrate, however, that the unit cost of feeder replacement must be sufficiently lower than the standard replacement cost and the refurbishment performed at an optimal time to realize the economic benefits associated with the refurbishment. (author)

  15. Development of an improved low profile hub seal refurbishment tool

    International Nuclear Information System (INIS)

    Wagg, L.

    1997-01-01

    The hub seal area of a fuel channel feeder coupling can be exposed to oxygen in the atmosphere if protective measures are not taken during maintenance outages. Exposure to oxygen can lead to pitting of the hub seal area. Although this is a rare occurrence, the resulting possibility of the feeder coupling leakage led to the development of a feeder hub refurbishment tool. To reduce time and man-rem exposure during feeder hub seal refurbishment, an improved low profile hub seat refurbishing tool has been developed. The improved tool design will allow for quick and controlled removal of material, and the restoration of a roll-burnished finish equivalent to the original requirements. The new tool can be used in maintenance operations, with the end fitting present, as well as under retube-type circumstances, with the end fitting removed. (author)

  16. Refractory porcelain enamel passive-thermal-control coating for high-temperature superalloys

    Science.gov (United States)

    Levin, H.; Auker, B. H.; Gardos, M. N.

    1973-01-01

    Study was conducted to match thermal expansion coefficients thereby preventing enamels from cracking. Report discusses various enamel coatings that are applied to two different high-temperature superalloys. Study may be of interest to manufacturers of chemical equipment, furnaces, and metal components intended for high-temperature applications.

  17. Refurbishment and Automation of the Thermal/Vacuum Facilities at the Goddard Space Flight Center

    Science.gov (United States)

    Donohue, John T.; Johnson, Chris; Ogden, Rick; Sushon, Janet

    1998-01-01

    The thermal/vacuum facilities located at the Goddard Space Flight Center (GSFC) have supported both manned and unmanned space flight since the 1960s. Of the 11 facilities, currently 10 of the systems are scheduled for refurbishment and/or replacement as part of a 5-year implementation. Expected return on investment includes the reduction in test schedules, improvements in the safety of facility operations, reduction in the complexity of a test and the reduction in personnel support required for a test. Additionally, GSFC will become a global resource renowned for expertise in thermal engineering, mechanical engineering and for the automation of thermal/vacuum facilities and thermal/vacuum tests. Automation of the thermal/vacuum facilities includes the utilization of Programmable Logic Controllers (PLCs) and the use of Supervisory Control and Data Acquisition (SCADA) systems. These components allow the computer control and automation of mechanical components such as valves and pumps. In some cases, the chamber and chamber shroud require complete replacement while others require only mechanical component retrofit or replacement. The project of refurbishment and automation began in 1996 and has resulted in the computer control of one Facility (Facility #225) and the integration of electronically controlled devices and PLCs within several other facilities. Facility 225 has been successfully controlled by PLC and SCADA for over one year. Insignificant anomalies have occurred and were resolved with minimal impact to testing and operations. The amount of work remaining to be performed will occur over the next four to five years. Fiscal year 1998 includes the complete refurbishment of one facility, computer control of the thermal systems in two facilities, implementation of SCADA and PLC systems to support multiple facilities and the implementation of a Database server to allow efficient test management and data analysis.

  18. Radiation protection aspects of AECL's retube/refurbishment projects

    International Nuclear Information System (INIS)

    Zhuang, Y.; Boss, C.R.; Pontikakis, N.

    2007-01-01

    In contrast to the construction of a new nuclear reactor, Retube/Refurbishment of nuclear reactors that have been in operation for many years will involve fabrication of a new core in a radiation environment. Careful planning of the radiation protection (RP) program is crucial to ensure the protection of workers and the environment, and the success of the projects. This paper describes the key RP activities currently underway in AECL's Retube/Refurbishment projects, covering RP during retubing tooling and system designs, retubing work planning, retubing operation, and waste transfer and management. The discussion will focus on RP initiatives from engineering design aspects of the projects. (author)

  19. The BR2 refurbishment: from concept to achievements

    International Nuclear Information System (INIS)

    Gubel, P.

    2002-01-01

    The BR2 reactor is one of the major research reactors in the world. It's operation started in the early 1960's. Two major refurbishments operation have been carried out since then. The report gives an overview of the methodology and inspections, which resulted in a refurbishment action plan. The main realizations and complementary actions required by the Licensing Authorities are summarized. Finally the operation experience feedback, four years now after start-up, is briefly discussed as well as the main aspects of the present safety reassessment [ru

  20. Rotor pole refurbishment for hydrogenerators: insulation problems and solutions

    International Nuclear Information System (INIS)

    Reynolds, R.R.; Rux, L.

    2005-01-01

    Rotor poles for Unit 1 at Lower Granite Powerhouse were removed from the rotor and shipped to a repair facility for refurbishment. Upon inspection, it was found that all of the pole bodies exhibited a distinct bow, center to end, on the pole mounting surface. In some cases, the deflection was as much as 0.106 inch. Concerns were raised about how this condition might affect the ability to properly insulate and/or re-seat the poles. This paper presents details of the rotor pole and field winding evaluation, the problems encountered, and the solutions implemented to successfully refurbish the rotor poles and field winding. (author)

  1. Refurbishment and safety up-gradation of Cirus Reactor

    International Nuclear Information System (INIS)

    Rao, D.V.H.

    2004-01-01

    Cirus, a 40 MWth, vertical tank type research reactor, having a wide range of research facilities, was commissioned in 1960. This research facility has been operated and utilized extensively for nearly four decades. With a view to assess the residual life of the reactor, detailed ageing studies were carried out. Based on this, refurbishment work for life extension was undertaken. During this work, additional safety features were incorporated to improve the overall safety of the reactor. This lecture details the methodologies used for ageing studies and refurbishment activities for life extension with enhanced safety. (author)

  2. The metallurgy of superalloys part 2

    International Nuclear Information System (INIS)

    Abdelazim, M.E.; Hammad, F.H.

    1990-01-01

    This is part II of the report titled 'the metallurgy of superalloys'. It deals with the effect of heat treatment and operating conditions (thermal exposure and environment) on the mechanical properties of superalloys. The heat treatment is important in the development of superalloys through that it controls type, amount, size shape and distribution of the precipitate and the grain size of the matrix. The thermal exposure leads to reduction in the amount of the primary carbides and to precipitation of secondary carbides. Also it leads to the agglomeration and coarsening of gamma or the transformation of gamma phase to phase. The environment may lead to the internal oxidation, carburization, decarburization or sulphidization of the superalloys which may result in the degradation of their mechanical properties. This part gives also an example of applications of superalloys in the field of nuclear reactors especially high temperature-gas cooled reactors. Joined with this part a table which contains the major superalloys including its chemical analysis, creep rupture strength and some of its applications. 1 tab

  3. The metallurgy of superalloys part 1

    International Nuclear Information System (INIS)

    Abdelazim, M.E.; Hammad, F.H.

    1990-01-01

    This is part I of the report titled 'the metallurgy of superalloys'. In this part the structure, phases and systems of superalloys are reviewed. The role of alloying elements in the design of superalloys and the mechanical properties of superalloys are also reviewed. Superalloys are important in high temperature technology, especially above 700 degree c. They are 'super' mainly because their creep and stress rupture resistances are very high. Superalloys are based on an austenitic matrix including secondary phases, mainly gamma precipitates, inter and intragranular carbides mainly M 23 C 6 and M 6 C. They are classified into three systems, Ni-base, Fe-Ni base and Ce-base alloys. Different alloying elements mainly Cr, Mo, Al, Ti are added to increase the strength either by solid solution hardening (Cr, Mo, Al), precipitation hardening (A 1, Ti to produce gamma) or by dispersion hardening (Cr, Mo to form M 23 C 6 and M 6 C carbides) and to increase the oxidation resistance (Cr, Al). 3 tab., 2 fig

  4. Refurbishment and replacement efforts to mitigate ageing at Tarapur Atomic Power Station - an overview

    International Nuclear Information System (INIS)

    Katiyar, S.C.; Thattey, V.; Das, P.K.

    2006-01-01

    Tarapur Atomic Power Station (TAPS) - a twin Boiling Water Reactor unit and India's first Atomic Power Station was commissioned in April 1969, and was declared commercial in November 1969. Since then the light water moderated, low enriched uranium BWR with its demonstrated reliability and favourable economics is playing a vital role as a reliable source of power for the states of Maharashtra and Gujarat. The Power Station played a key role as a technology demonstrator validating the nuclear energy as safe and environmentally benign and economically viable alternate source of power generation in India. Built in the late sixties with state-of-the-art safety features prevailing then, TAPS has further evolved to be a safe plant with renovation and refurbishment efforts. Ageing Management Programme is in place at TAPS. Identification of systems, structures and components (SSCs) important to safety and availability, assessment of ageing degradation of these SSCs and mitigation through repair, replacement and refurbishment based on the investigations have enhanced the plant safety and reliability. The station's operating experience and feedback from BWRs operating abroad have also given inputs to Ageing Management Programme. A good number of major equipment have been replaced to mitigate ageing. Primary system piping, process heat exchangers, feed water heaters, turbine extraction system piping, turbine blades, emergency condenser tube bundles, various pumps, station batteries, electrical cables, circuit breakers etc. are some of them. Obsolescence is another aspect of ageing of a plant. Replacement of obsolete equipment and components particularly in C and I is another area where much headway has been made. Replacement and refurbishment of equipment have been done after detailed study and analysis so that current standards are met. Retrofitting the indigenously developed and fabricated equipment in a compact plant like TAPS was a difficult task and required lot of

  5. Darlington refurbishment - performance improvement programs goals and experience

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, N. [Ontario Power Generation, Toronto, ON (Canada)

    2015-07-01

    This paper discusses the refurbishment program at the Darlington site. The program focuses on safety, integrity, excellence and personnel. Worker safety and public safety are of the highest priority. Success resulted from collaborative engineering interface, collaborative front end planning, highly competent people and respectful relationship with partners and regulators.

  6. Refurbishment of the NPP Dukovany I and C System

    International Nuclear Information System (INIS)

    Karpeta, C.; Rosol, J.

    2004-01-01

    An overview of the NPP Dukovany Instrumentation and Control (I and C) refurbishment project is presented in this paper from the standpoint of both its management and technical aspects. Reasons for taking the decision to replace the original plant I and C system are outlined and the objectives set for the refurbishment project are stated. The paper is focusing on describing more in detail the first part of the refurbishment, i.e. replacement of the I and C portions of the plant systems important to nuclear safety and the process information system. This includes the reactor trip system, engineered safety features actuation system, reactor power limitation system, reactor power control system, post-accident monitoring system, reactor core monitoring system and unit data acquisition and processing system. Information is given on the main processes of the project, i.e. the bidding, design, manufacturing, installation and commissioning. Specific licensing process applied to this refurbishment project is also outlined. An account of the current status of the project implementation is given. (author)

  7. Analysis of Factors Influencing Building Refurbishment Project Performance

    Directory of Open Access Journals (Sweden)

    Ishak Nurfadzillah

    2018-01-01

    Full Text Available Presently, the refurbishment approach becomes favourable as it creates opportunities to incorporate sustainable value with other building improvement. In this regard, this approach needs to be implemented due to the issues on overwhelming ratio of existing building to new construction, which also can contribute to the environmental problem. Refurbishment principles imply to minimize the environmental impact and upgrading the performance of an existing building to meet new requirements. In theoretically, building project’s performance has a direct bearing on related to its potential for project success. However, in refurbishment building projects, the criteria for measure are become wider because the projects are a complex and multi-dimensional which encompassing many factors which reflect to the nature of works. Therefore, this impetus could be achieve by examine the direct empirical relationship between critical success factors (CSFs and complexity factors (CFs during managing the project in relation to delivering success on project performance. The research findings will be expected as the basis of future research in establish appropriate framework that provides information on managing refurbishment building projects and enhancing the project management competency for a better-built environment.

  8. IEC 61850 based refurbishment strategies for protection and automation systems

    Energy Technology Data Exchange (ETDEWEB)

    Tholomier, D. [Areva T and D Automation Canada Inc., Monteal, PQ (Canada); Hossenlopp, L. [Areva T and D Automation Inc., Paris (France); Apostolov, A. [Omicron Electronics, Houston, TX (United States)

    2008-07-01

    Electric utilities are currently facing the challenge of refurbishing aging transmission networks and power system infrastructure at a time of severe economic, environmental and competitive constraints. This paper addressed the issue of an appropriate approach to retrofit the hardware and software of substation secondary systems, and how IEC standards could be used to set up a long term strategy. The first part of the paper considered an asset management strategy for refurbishing substation secondary systems, while the second part of the paper addressed the strategies for refurbishing existing power plants. The final section of the paper analyzed refurbishment strategies designed to protect power distribution systems. The impact of IEC 61850 and how legacy devices can be integrated in substation automation systems were discussed. It was concluded that new SCADA systems are needed to handle new technology. Additional features like remote control, remote settings, remote disturbance records analysis and remote maintenance are also needed to properly operate the power system. The value of preventive maintenance using remote monitoring systems to determine the status of all the digital electronic devices installed in substation was also discussed. IEC 61850 offers several opportunities to improve grid operation and control. It supports interoperability between protective relays and control devices from different manufacturers in the substation, which is required in order to achieve substation level interlocking, protection and control functions and improve the efficiency of microprocessor based relays applications. This technology has now passed the initial stage of implementation and several projects are underway worldwide. 13 figs.

  9. An Integrated Refurbishment Design Process to Energy Efficiency

    NARCIS (Netherlands)

    Konstantinou, T.; Knaack, U.

    2013-01-01

    Given the very low renewal rate of the building stock, the efforts to reduce energy demand must focus on the existing residential buildings. Even though awareness has been raised, the effect on energy efficiency is often neglected during the design phase of refurbishment projects. This paper

  10. Energetic Refurbishment of Historic Brick Buildings: Problems and Opportunities

    Science.gov (United States)

    Zagorskas, Jurgis; Paliulis, Gražvydas Mykolas; Burinskienė, Marija; Venckauskaitė, Jūratė

    2013-12-01

    Building standards for energy effectiveness are increasing constantly and the market follows these changes by constructing new buildings in accordance with standards and refurbishment of the existing housing stock. Comprehensive trends in European construction market show tremendous increase in building retrofit works. It can be predicted that after the end of this decade, more than half of the construction works in European cities will be taking place in existing buildings, pushing the construction of new buildings to a less important role. Such a growth in building refurbishment works is creating a demand for suitable materials, retrofitting techniques and research. The differences between refurbishment of new-build projects and historical or valuable buildings are insufficiently recognized - mostly the buildings without further cultural preservation requirements are studied. This article covers the theme of refurbishment measures in historical buildings - the specific measures like inside insulation which are allowed due to the valuable façade or other heritage preservation requirements. An overview of other innovative methods for energy saving in existing buildings and their potential is given.

  11. Airline fuel saving through JT9D engine refurbishment

    Energy Technology Data Exchange (ETDEWEB)

    Allison, J.W.; Weisel, D.R.

    1981-01-01

    Areas are identified in the JT9D engine where the potential exists for either further performance recovery following repair, or for improved performance retention. A number of new procedures and tools which will improve performance recovery are described. Improvements in inspection techniques are discussed. Operational techniques which will improve performance retention and impact degree of refurbishment required are also presented.

  12. Analysis of Factors Influencing Building Refurbishment Project Performance

    Science.gov (United States)

    Ishak, Nurfadzillah; Aswad Ibrahim, Fazdliel; Azizi Azizan, Muhammad

    2018-03-01

    Presently, the refurbishment approach becomes favourable as it creates opportunities to incorporate sustainable value with other building improvement. In this regard, this approach needs to be implemented due to the issues on overwhelming ratio of existing building to new construction, which also can contribute to the environmental problem. Refurbishment principles imply to minimize the environmental impact and upgrading the performance of an existing building to meet new requirements. In theoretically, building project's performance has a direct bearing on related to its potential for project success. However, in refurbishment building projects, the criteria for measure are become wider because the projects are a complex and multi-dimensional which encompassing many factors which reflect to the nature of works. Therefore, this impetus could be achieve by examine the direct empirical relationship between critical success factors (CSFs) and complexity factors (CFs) during managing the project in relation to delivering success on project performance. The research findings will be expected as the basis of future research in establish appropriate framework that provides information on managing refurbishment building projects and enhancing the project management competency for a better-built environment.

  13. Embalse refurbishment - aging, safety assessment, and the path forward

    International Nuclear Information System (INIS)

    Sainz, R.; Fornero, D.; Diaz, G.; Gold, R.; Dam, R.; McCrea, L.

    2009-01-01

    The Embalse Nuclear Power Station has been engaged in Pre-refurbishment activities for two years. The primary focus has been on the first phase Pre-Project Condition Assessment Program (PCAP). This phase of the Refurbishment and Life Extension (RLE) project consists of all preparatory activities that are required to define the refurbishment scope and costs, and for input into the utility business case for the RLE project. As part of an overall Plant Life Management (PLiM) program, the following activities have been performed: 1. Systematic and rigorous condition assessments / life assessments (including Health Prognosis and Recommendations); 2. Assessment of design and safety analysis features at Embalse, relative to current technology and licensing practices; 3. Pre-Project activities related to: Retube, Steam Generator replacement, and Digital Control Computer (DCC) replacement. The program has been a joint effort of Embalse NPS-NASA, AECL, ANSALDO and several other support organizations. Details of the planned program were addressed previously in a paper presented at the 28th CNS Conference (2007), entitled 'Embalse Refurbishment - Pre-Project Condition Assessment Phase 1'. Since that time, significant progress has been made towards completing the assessment program and planning for the next steps. This paper presents the progress of Refurbishment and Life Extension (RLE) Program at Embalse Nuclear Power Station with specific emphasis on the PCAP efforts. This includes a discussion of the benefits and lessons learned from RLE project's perspective, and an overview of some key conclusions of the aging assessments. Finally, this paper outlines the path forward. It should be noted that results of assessments presented in this paper are very conservative. This is driven largely by the fact that there are currently uncertainties in equipment condition that can be addressed through the activities recommended as an outcome of these assessments. (author)

  14. Refurbishment and Automation of Thermal Vacuum Facilities at NASA/GSFC

    Science.gov (United States)

    Dunn, Jamie; Gomez, Carlos; Donohue, John; Johnson, Chris; Palmer, John; Sushon, Janet

    1999-01-01

    The thermal vacuum facilities located at the Goddard Space Flight Center (GSFC) have supported both manned and unmanned space flight since the 1960s. Of the eleven facilities, currently ten of the systems are scheduled for refurbishment or replacement as part of a five-year implementation. Expected return on investment includes the reduction in test schedules, improvements in safety of facility operations, and reduction in the personnel support required for a test. Additionally, GSFC will become a global resource renowned for expertise in thermal engineering, mechanical engineering, and for the automation of thermal vacuum facilities and tests. Automation of the thermal vacuum facilities includes the utilization of Programmable Logic Controllers (PLCs), the use of Supervisory Control and Data Acquisition (SCADA) systems, and the development of a centralized Test Data Management System. These components allow the computer control and automation of mechanical components such as valves and pumps. The project of refurbishment and automation began in 1996 and has resulted in complete computer control of one facility (Facility 281), and the integration of electronically controlled devices and PLCs in multiple others.

  15. Microstructural and mechanical characterization of injection molded 718 superalloy powders

    Energy Technology Data Exchange (ETDEWEB)

    Özgün, Özgür [Bingol University, Faculty of Engineering and Architecture, Mechanical Eng. Dep., 12000 Bingol (Turkey); Gülsoy, H. Özkan, E-mail: ogulsoy@marmara.edu.tr [Marmara University, Technology Faculty, Metallurgy and Materials Eng. Dep., 34722 Istanbul (Turkey); Yılmaz, Ramazan [Sakarya University, Technology Faculty, Metallurgy and Materials Eng. Dep., 54187 Sakarya (Turkey); Fındık, Fehim [Sakarya University, Technology Faculty, Metallurgy and Materials Eng. Dep., 54187 Sakarya (Turkey) and International University of Sarajevo, Faculty of Engineering and Natural Sciences, Department of Mechanical Engineering, 71000 Sarajevo, Bosnia and Herzegovina (Bosnia and Herzegowina)

    2013-11-05

    Highlights: •Microstructural and mechanical properties of injection molded Nickel 718 superalloy were studied. •The maximum sintered density achieved this study was 97.3% at 1290 °C for 3 hours. •Tensile strength of 1022 MPa and elongation of 5.3% were achieved for sintered-heat treated samples. -- Abstract: This study concerns with the determination of optimum production parameters for injection molding 718 superalloy parts. And at the same time, microstructural and mechanical characterization of these produced parts was also carried out. At the initial stage, 718 superalloy powders were mixed with a multi-component binder system for preparing feedstock. Then the prepared feedstock was granulated and shaped by injection molding. Following this operation, the shaped samples were subjected to the debinding process. These samples were sintered at different temperatures for various times. Samples sintered under the condition that gave way to the highest relative density (3 h at 1290 °C) were solution treated and aged respectively. Sintered, solution treated and aged samples were separately subjected to microstructural and mechanical characterization. Microstructural characterization operations such as X-ray diffraction, optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and elemental analysis showed that using polymeric binder system led to plentiful carbide precipitates to be occurred in the injection molded samples. It is also observed that the volume fractions of the intermetallic phases (γ′ and γ″) obtained by aging treatment were decreased due to the plentiful carbide precipitation in the samples. Mechanical characterization was performed by hardness measurements and tensile tests.

  16. Refurbishment and safety management of JMTR in extended showdown

    International Nuclear Information System (INIS)

    Ide, Hiroshi; Hori, Naohiko; Gorai, Shigeru; Kusunoki, Tsuyoshi

    2011-06-01

    Japan Materials Testing Reactor (JMTR) is a testing reactor dedicated to the irradiation tests of materials and fuels. The reactor type of the JMTR is light water moderated and cooled tank type. It achieved first criticality in 1968. Operation was started in 1970. The JMTR had been being operated for 38 years from first criticality to the JMTR No.165 cycle finished. Periodic Safety Review (PSR) was carried out with confirming the integrity inspection of the JMTR reactor facilities. And the 10 years maintenance plan was made in 2004. After that, the restart of the JMTR has been strongly requested from various users as the only irradiation testing reactor in Japan. Finally, Japan Atomic Energy Agency (JAEA) decided the refurbishment and restart of the JMTR in December 2006, and the refurbishment works was started from FY 2007. The equipment to remain in use and that which needs replacing before the restart of the JMTR was selected after having been evaluated on its damage and wear due to aging significance in safety functions, past safety-related maintenance date, and the enhancement of facility operation. The renewal work of power supply system, boiler, radioactive waste facility, etc. was already carried out as scheduled. The renewal work of reactor control system, nuclear instrumentation system and so on is being carried out. As for the safety management during reactor operation, the facility periodical own inspection and daily inspection is carried out for the purpose of maintaining soundness and reliability of facilities and equipments. And it is confirmed that the performance of facilities and equipments is maintained. As for the radiation control, irradiation dose limit determined by the law is obeyed. Based on the Concept of radiation protection of the International Commission on Radiation Protection (ICRP), reduction of dose is endeavored. The safety management during reactor shutdown is also carried out as well as it of reactor operation term. However, the

  17. Refurbishment of the regulating and control equipment, Task 3.08/04-05; Zadatak 3.08/04-05 Remont uredjaja za regulaciju i upravljanje

    Energy Technology Data Exchange (ETDEWEB)

    Nikolic, M; Popovic, B [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    In addition to the planned refurbishment and maintenance of the RA reactor control and regulating systems, this report describes the maintenance of the reactor protection and safety systems. According to the instructions included in this report the components of these systems were tested to verify their reliability.

  18. Refurbishment of an Analytical Laboratory Hot Cell Facility

    International Nuclear Information System (INIS)

    Rosenberg, K.; Henslee, S.P.; Michelbacher, J.A.; Coleman, R.M.

    1997-01-01

    An Analytical Laboratory Hot Cell (ALHC) Facility at Argonne National Laboratory-West (ANL-W) was in service for nearly thirty years. In order to comply with DOE regulations governing such facilities and meet ANL-W programmatic requirements, a major refurbishment effort was undertaken. All penetrations within the facility were sealed; the ventilation system was redesigned, upgraded and replaced; the manipulators were replaced; the hot cell windows were removed, refurbished, and reinstalled; all hot cell utilities were replaced; a lead-shielded glovebox housing an Inductively Coupled Plasma - Atomic Emission Spectrometer (ICP-AES) System was interfaced with the hot cells, and a new CO2 fire suppression system and other ALHC support equipment were installed

  19. BIM applied in historical building documentation and refurbishing

    Science.gov (United States)

    Cheng, H.-M.; Yang, W.-B.; Yen, Y.-N.

    2015-08-01

    Historical building conservation raises two important issues which are documentation and refurbishing. For the recording and documentation, we already have developed 3d laser scanner and such photogrammetry technology those represent a freeze object of virtual reality by digital documentation. On the other hand, the refurbished engineering of historic building is a challenge for conservation heritage which are not only reconstructing the damage part but also restoring tangible cultural heritage. 3D digital cultural heritage models has become a topic of great interest in recent years. One reason for this is the more widespread use of laser scanning and photogrammetry for recording cultural heritage sites. These technologies have made it possible to efficiently and accurately record complex structures remotely that would not have been possible with previous survey methods. In addition to these developments, digital information systems are evolving for the presentation, analysis and archival of heritage documentation.

  20. Refurbishment of the Oregon State University rotating rack

    International Nuclear Information System (INIS)

    Higginbotham, J.F.

    1991-01-01

    TRIGA reactors have experienced operational difficulties with the rotating racks used for sample irradiation. The most common problem occurs when the rack seizes, and the corrective action taken is replacement of the rack assembly. This paper describes the symptoms leading to rack failure and a refurbishment procedure to correct the problem without replacing the rack at the Oregon State University TRIGA Reactor (OSTR) Facility. This procedure was accomplished with extraordinary results from an operational and a radiation protection standpoint. The refurbishment has extended the useful life of this reactor facility with minimal financial impact. Given the declining number of university-based research reactors, it is in the nation's best interest to maintain the currently operating research reactor facilities, and the described procedure can aid in achieving that goal

  1. Study on identification method of auto refurbishment test

    Science.gov (United States)

    Jiang, Zhenfei; Feng, Qingfu; Wang, Zhengyu; Jiang, Suqin; Chen, Xing; Zheng, Shaoyuan; Li, Bokui

    2018-04-01

    In recent years, a large number of refurbished cars inflow into the market as new cars. The traditional methods to identify refurbished cars are mostly based on experience, the subjectivity is too high and the credibility is low. In the production of automobile, the state and the automobile industry set clear standards for the thickness of the automobile paint. There is a big difference between the thickness of machine spraying and manual spraying. By studying this difference and combining with the standard, it can be identified accurately whether the car has been renovated; during the second assembly process, the surface of some parts (such as bolts) will have obvious signs of wear and tear due to the regular assembly and disassembly, it can also be identified accurately through the study of these assembly traces.

  2. Project Experiences in Research Reactor Ageing Management, Modernization and Refurbishment. Report of a Technical Meeting on Research Reactor Ageing Management, Modernization and Refurbishment

    International Nuclear Information System (INIS)

    2014-08-01

    Research reactors have played an important role in several scientific fields for around 60 years: in the development of nuclear science and technology; in the valuable generation of radioisotopes for various applications; and in the development of human resources and skills. Moreover, research reactors have been effectively utilized to support sustainable development in more than 60 countries worldwide. More than half of all operating research reactors are now over 40 years old, with many exceeding their originally conceived design life. The majority of operating research reactors face challenges due to the negative impacts of component and system ageing, which manifest in a number of forms. This situation was highlighted by a serious medical isotope supply crisis which peaked in mid-2010, when several major producing reactors underwent prolonged shutdowns due to extensive necessary overhauls of various systems. Several facilities have established a proactive systematic approach to managing ageing or mitigating its impact on safety and availability of isotopes. Others have tried to prevent or remedy the drawbacks of ageing on a case by case basis. Overall, a large body of knowledge related to ageing issues exists in many Member States. Collecting and sharing this information within the research reactor community can provide a solid foundation to develop a more systematic approach — that is, an ageing management programme to prevent negative consequences of ageing on the safety, and the operability and lifetime of operating, or even future, reactors. It may also help organizations to manage research reactors that have been in an extended shutdown state by ensuring that any required systems are operated and maintained in a safe manner prior to final decommissioning and disposal of fuel to safe storage facilities. Sharing experiences from projects undertaken to refurbish or replace equipment and systems, satisfy safety and regulatory requirements, improve

  3. Project Experiences in Research Reactor Ageing Management, Modernization and Refurbishment. Report of a Technical Meeting on Research Reactor Ageing Management, Modernization and Refurbishment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-08-15

    Research reactors have played an important role in several scientific fields for around 60 years: in the development of nuclear science and technology; in the valuable generation of radioisotopes for various applications; and in the development of human resources and skills. Moreover, research reactors have been effectively utilized to support sustainable development in more than 60 countries worldwide. More than half of all operating research reactors are now over 40 years old, with many exceeding their originally conceived design life. The majority of operating research reactors face challenges due to the negative impacts of component and system ageing, which manifest in a number of forms. This situation was highlighted by a serious medical isotope supply crisis which peaked in mid-2010, when several major producing reactors underwent prolonged shutdowns due to extensive necessary overhauls of various systems. Several facilities have established a proactive systematic approach to managing ageing or mitigating its impact on safety and availability of isotopes. Others have tried to prevent or remedy the drawbacks of ageing on a case by case basis. Overall, a large body of knowledge related to ageing issues exists in many Member States. Collecting and sharing this information within the research reactor community can provide a solid foundation to develop a more systematic approach — that is, an ageing management programme to prevent negative consequences of ageing on the safety, and the operability and lifetime of operating, or even future, reactors. It may also help organizations to manage research reactors that have been in an extended shutdown state by ensuring that any required systems are operated and maintained in a safe manner prior to final decommissioning and disposal of fuel to safe storage facilities. Sharing experiences from projects undertaken to refurbish or replace equipment and systems, satisfy safety and regulatory requirements, improve

  4. Forging Oxide-Dispersion-Strengthened Superalloys

    Science.gov (United States)

    Harf, F. H.; Glasgow, T. K.; Moracz, D. J.; Austin, C. M.

    1986-01-01

    Cladding of mild steel prevents surface cracking when alloy contacts die. Continual need for improvements in properties of alloys capable of withstanding elevated temperatures. Accomplished by using oxide-dispersion-strengthed superalloys such as Inconel Alloy MA 6000. Elevated tensile properties of forged alloy equal those of hot-rolled MA 6000 bar. Stress-rupture properties somewhat lower than those of bar stock but, at 1,100 degrees C, exceed those of strongest commercial single crystal, directionally solidified and conventionally cast superalloys.

  5. Status of FRJ-2 refurbishment of tank pipes and essential results of aging analysis

    International Nuclear Information System (INIS)

    Hansen, G.; Thamm, G.; Thome, M.

    1993-01-01

    An aging evaluation program for FRJ-2 (DIDO) of the Forschungszentrum Juelich GmbH has been developed and is currently executed in cooperation with the licensing and regulatory and TUV experts in order to determine the overall life expectancy of the facility and to identify critical systems and components that need to be upgraded or refurbished for future safe reactor operation. In Phase A (completed) a so called master list of the FRJ-2 mechanical, electrical and structural components was compiled on a system-by system basis and the operational documentation with respect to regular inspections, maintenance, repair and unusual occurences was carefully examined. Critical components were selected and their ageing respectively life limiting mechanisms identified. In Phase (currently under way) special inspections, examinations and tests for critical systems/components are being elaborated, executed and evaluated. Current work is being concentrated on non replaceable components (e.g. reactor aluminium tank (RAT) and the connecting pipes to the primary cooling circuit, the reactor steel tank and pipe work inside the concrete reactor block). As a consequence of first results of the aging evaluation program and due to leaks in the weir and drain pipes of the RAT a repair/refurbishment program was set up for the Al-RAT pipes (risers, downcomers weir and drain pipes) and the steel guide tubes. Details of the r/r program which is in far progress and first essential results of the aging evaluation will be presented. The results achieved until today are encouraging with respect to safe reactor operation on short and medium term. (author)

  6. Status of FRJ-2 Refurbishment of tank pipes and essential results of aging analysis

    International Nuclear Information System (INIS)

    Hansen, G.; Thamm, G.; Thome, M.

    1994-01-01

    An aging evaluation program for FRJ-2 (DIDO) of the Forschungszentrum Juelich GmbH has been developed and is currently executed in cooperation with the licensing and regulatory and TUEV experts in order to determine the overall life expectancy of the facility and to identify critical systems and components that need to be upgraded or refurbished for future safe reactor operation. In Phase A (completed) a so called master list of the FRJ-2 mechanical, electrical and structural components was compiled on a system-by system basis and the operational documentation with respect to regular inspections, maintenance, repair and unusual occurrences was carefully examined. Critical components were selected and their ageing respectively life limiting mechanisms identified. In Phase B (currently under way) special inspections, examinations and tests for critical systems/components are being elaborated, executed and evaluated. Current work is being concentrated on non replaceable components (e.g. reactor aluminium tank (RAT) and the connecting pipes to the primary cooling circuit, the reactor steel tank and pipe work inside the concrete reactor block). As a consequence of first results of the aging evaluation program and due to leaks in the weir and drain pipes of the RAT a repair/refurbishment program was set up for the Al-RAT pipes (risers, downcomers, weir and drain pipes) and the steel guide tubes. Details of the r/r program which is in far progress and first essential results of the aging evaluation will be presented. The results achieved until today are encouraging with respect to safe reactor operation on short and medium term. (J.P.N.)

  7. Corrosion inhibition measures in primary cooling water system during refurbishment of Cirus, re-commissioning and subsequent operation

    International Nuclear Information System (INIS)

    Rai, K.K.; Ramesh, N.; Sharma, R.C.

    2008-01-01

    Cirus is a 40 MWth, heavy water moderated, demineralized light water cooled, natural uranium fuelled research reactor. Reactor was commissioned in year 1960 and operated satisfactorily till 1990. After that availability factor started decreasing mainly due to equipment outage exhibiting signs of ageing. Based upon systematic ageing studies and assessment of condition of systems, structures and components, a refurbishment plan including safety upgrades was drawn up. Reactor was shut down in October 1997 for execution of jobs. After completion of refurbishment jobs reactor was started back in October 2002 and power operation was achieved in 2003. Primary cooling water (PCW) system consists of re-circulating pumps, heat exchangers, expansion tank, piping, valves, emergency storage reservoir (Ball Tank) and other components. Normally the fission heat from fuel is removed by re-circulating coolant in closed loop and transferred to seawater via heat exchangers. In case of outage of pumps, shut down cooling is provided by flow of water from Ball Tank under gravity to the underground dump tanks. The dissolved oxygen is maintained below 2 ppm and pH is maintained neutral to minimize corrosion of fuel cladding (Aluminum). This paper highlights the experience gained during segmentation of primary cooling water pipelines for pressure testing, measures taken to corrosion inhibition of primary cooling water lines to permit execution of refurbishment jobs, inspections and actions taken to repair/replace the corroded PCW pipe line segments, observations regarding corrosion related failures, re-commissioning of the system after refurbishment, assessment for safe reactor operation and experience during power operation. (author)

  8. The status of the LANSCE refurbishment project (LANSCE-R)

    International Nuclear Information System (INIS)

    Erickson, John Leonard; Jones, Kevin; Streve, Michael

    2008-01-01

    The Los Alamos Neutron Science Center (LANSCE) accelerator is an 800-MeV proton linac that drives user facilities for isotope production, proton radiography, ultra-cold neutrons, weapons neutron research and various sciences using neutron scattering. The LANSCE Refurbishment Project (LANSCE-R) is an ambitious project to refurbish key elements of the LANSCE accelerator that are becoming obsolete or nearing end-of-life. The conceptual design phase for the project is funded and underway. The 5 year, $170M (US) project will enable future decades of reliable, high-performance operation. It will replace a substantial fraction of the radio-frequency power systems (gridded tubes and klystrons) with modern systems, completely refurbish the original accelerator control and timing systems, replace obsolete diagnostic devices, and modernize other ancillary systems. An overview of the LANSCE-R project will be presented. The functional and operating requirements will be discussed, the proposed technical solutions presented, and the plan for successful project execution while meeting annual customer expectations for beam delivery will be reviewed.

  9. Recent advances in the utilization and the irradiation technology of the refurbished BR2 reactor

    International Nuclear Information System (INIS)

    Dekeyser, J.; Benoit, P.; Decloedt, C.; Pouleur, Y.; Verwimp, A.; Weber, M.; Vankeerberghen, M.; Ponsard, B.

    1999-01-01

    Operation and utilization of the materials testing reactor BR2 at the Belgian Nuclear Research Centre (SCK·CEN) has since its start in 1963 always followed closely the needs and developments of nuclear technology. In particular, a multitude of irradiation experiments have been carried out for most types of nuclear power reactors, existing or under design. Since the early 1990s and increased focus was directed towards more specific irradiation testing needs for light water reactor fuels and materials, although other areas of utilization continued as well (e.g. fusion reactor materials, safety research, ...), including also the growing activities of radioisotope production and silicon doping. An important milestone was the decision in 1994 to implement a comprehensive refurbishment programme for the BR2 reactor and plant installations. The scope of this programme comprised very substantial studies and hardware interventions, which have been completed in early 1997 within planning and budget. Directly connected to this strategic decision for reactor refurbishment was the reinforcement of our efforts to requalify and upgrade the existing irradiation facilities and to develop advanced devices in BR2 to support emerging programs in the following fields: - LWR pressure vessel steel, - LWR irradiation assisted stress corrosion cracking (IASCC), - reliability and safety of high-burnup LWR fuel, - fusion reactor materials and blanket components, - fast neutron reactor fuels and actinide burning, - extension and diversification of radioisotope production. The paper highlights these advances in the areas of BR2 utilisation and the ongoing development activities for the required new generation of irradiations devices. (author)

  10. Current status of operation, utilization and refurbishment of the Dalat nuclear research reactor

    International Nuclear Information System (INIS)

    Pham Duy Hien.

    1993-01-01

    The reconstructed nuclear research reactor at Dalat, Vietnam has been put into operation since March 1984. Up to present a cumulative operation time of 13,172 hrs at nominal power (500 kW) has been recorded. Production of radioisotopes for medical uses, element analysis by using activation techniques, as well as fundamental and applied research with filtered neutrons are the main activities of reactor utilizations. The problems facing Dalat Nuclear Research Institute are the ageing of the re-used TRIGA-MARK-II reactor components (especially the corrosion of the reactor tank), as well as the obsolescence of many equipment and components of the reactor control and instrumentation system. Refurbishment works are being in process with the technical and financial supports from the Vietnam government and the IAEA. (author). 7 refs, 2 tabs, 10 figs

  11. The Lo Aguirre research reactor refurbishment

    International Nuclear Information System (INIS)

    Torres-Oviedo, G.

    1990-01-01

    A description is given of the main work which had to be performed on the experimental reactor of the Lo Aguirre nuclear power plant (RECH-2), following which it recently came into operation. In particular, an outline is given of the main changes and improvements made with regard to reactor physics calculations, the systems and components in the facility, and repair of existing fuel elements. Special importance was attached to the definition, application and meeting of nuclear safety requirements and the implementation of a consistent quality assurance programme. Certain aspects of the work performed, by virtue of the scope and importance of the tasks involved, resulted in clear improvements to and modernization of the facility - for example, the construction of a new control room, the construction of a computerized radiation protection and surveillance control room, the reconstruction of the primary coolant circuit, the complete refitting of reactor instrumentation to incorporate a computerized data acquisition system, the redesign and construction of reactor water treatment plants, improvements in experimental devices and the design and construction of new experimental devices. The reactor, construction of which was resumed in 1986, attained criticality on 6 September 1989 using the HEU fuel available. We are now at the stage of characterizing the reactor by measuring process and nuclear parameters prior to commencing power operation

  12. Chemical driving force for rafting in superalloys

    CSIR Research Space (South Africa)

    Nabarro, FRN

    1997-08-15

    Full Text Available The author provides a brief overview of the chemical driving forces for rafting in superalloys. Until recently, all theories of the driving force for rafting have considered the compositions of the two phases to be fixed, although accepting...

  13. MGI-oriented High-throughput Measurement of Interdiffusion Coefficient Matrices in Ni-based Superalloys

    Directory of Open Access Journals (Sweden)

    TANG Ying

    2017-01-01

    Full Text Available One of the research hotspots in the field of high-temperature alloys was to search the substitutional elements for Re in order to prepare the single-crystal Ni-based superalloys with less or even no Re addition. To find the elements with similar or even lower diffusion coefficients in comparison with that of Re was one of the effective strategies. In multicomponent alloys, the interdiffusivity matrix were used to comprehensively characterize the diffusion ability of any alloying elements. Therefore, accurate determination of the composition-dependant and temperature-dependent interdiffusivities matrices of different elements in γ and γ' phases of Ni-based superalloys was high priority. The paper briefly introduces of the status of the interdiffusivity matrices determination in Ni-based superalloys, and the methods for determining the interdiffusivities in multicomponent alloys, including the traditional Matano-Kirkaldy method and recently proposed numerical inverse method. Because the traditional Matano-Kirkaldy method is of low efficiency, the experimental reports on interdiffusivity matrices in ternary and higher order sub-systems of the Ni-based superalloys were very scarce in the literature. While the numerical inverse method newly proposed in our research group based on Fick's second law can be utilized for high-throughput measurement of accurate interdiffusivity matrices in alloys with any number of components. After that, the successful application of the numerical inverse method in the high-throughput measurement of interdiffusivity matrices in alloys is demonstrated in fcc (γ phase of the ternary Ni-Al-Ta system. Moreover, the validation of the resulting composition-dependant and temperature-dependent interdiffusivity matrices is also comprehensively made. Then, this paper summarizes the recent progress in the measurement of interdiffusivity matrices in γ and γ' phases of a series of core ternary Ni-based superalloys achieved in

  14. Was It Really Worth Pain? Refurbishment of Mercedes-Benz Trucks by Botswana Defence Force

    National Research Council Canada - National Science Library

    Rangobana, Samuel A; Alkebaisi, Hussain K

    2005-01-01

    .... Logistics statistics, for refurbished trucks returned to user units, are also gathered from the asset management software database, Mincom Ellipse, in use by the Botswana Defence Force Mechanical...

  15. The probability safety assessment impact on the BR2 refurbishment

    International Nuclear Information System (INIS)

    Pouleur, Yvan

    1995-01-01

    The probabilistic safety assessment (PSA) study has proven its worth by establishing a sensitive safety screening of the reactor. It has focused engineering forces to technically improve safety systems and to measure the influence of functional modifications. In the future, the project will be developed in a living way, to reinforce the present structure along with continuous safety monitoring of the reactor and to develop engineers and operators safety skills. This paper presents the PSA impact on the BR2 (Belgian Reactor Two) refurbishment. (author)

  16. Industry partnership: adding value to nuclear refurbishment and maintenance

    International Nuclear Information System (INIS)

    Gibbins, T.; Bains, N.; Morikawa, D.

    2008-01-01

    The Point Lepreau Generating Station was the first CANDU 6 unit to be licensed for operation, beginning commercial operation in 1983. It is now become the first CANDU 6 to undergo full refurbishment. As part of the overall project, all 380 fuel channels and associated feeders will be removed and replaced. In order to undertake this project, it was necessary for AECL to design and develop over fifty 'first-of-a-kind tools' for fuel channel and calandria tube replacement. This paper outlines the complexity of the retube tooling project and the industry partnership strategy for the engineered tooling systems development. (author)

  17. Detection of creep damage in a nickel base superalloy using NDE techniques

    International Nuclear Information System (INIS)

    Carreon, H.; Mora, B.; Barrera, G.

    2009-10-01

    Due to elevated temperatures, excessive stresses and severed corrosion conditions, turbine engine components are subject to creep processes that limit the components life such as a turbine bucket. The failure mechanism of a turbine bucket is related primarily to creep and corrosion and secondarily to thermal fatigue. As a result, it is desirable to assess the current conditions of such turbine component. This study uses the eddy current nondestructive evaluation technique in an effort to monitor the creep damage in a nickel base super-alloy, turbine bucket after service. The experimental results show an important electrical conductivity variation in eddy current images on the creep damage zone of nickel base super-alloy samples cut from a turbine bucket. Thermoelectric power measurements were also conducted in order to obtain a direct correlation between the presence of material changes due to creep damage and the electrical conductivity measurements. This research work shows an alternative non-destructive method in order to detect creep damage in a nickel base super-alloy turbine bucket. (Author)

  18. Task 3.08/04-04, refurbishment of the dosimetry control equipment; Zadatak 3.08/04-04 Remont uredjaja dozimetrijske kontrole

    Energy Technology Data Exchange (ETDEWEB)

    Nikolic, M; Milosevic, M [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    During three years of operation the designed RA dosimetry system showed satisfactory performance. During the period planned for maintenance and refurbishment of the RA reactor the functionality of the dosimetry system was tested and verified, the components were cleaned and calibrated. The system was operated for 24 hours for testing the reliability of components and whole system. This report describes detailed instructions and actions performed for these activities.

  19. STABILITY ANALYSIS OF RADIAL TURNING PROCESS FOR SUPERALLOYS

    Directory of Open Access Journals (Sweden)

    Alberto JIMÉNEZ

    2017-07-01

    Full Text Available Stability detection in machining processes is an essential component for the design of efficient machining processes. Automatic methods are able to determine when instability is happening and prevent possible machine failures. In this work a variety of methods are proposed for detecting stability anomalies based on the measured forces in the radial turning process of superalloys. Two different methods are proposed to determine instabilities. Each one is tested on real data obtained in the machining of Waspalloy, Haynes 282 and Inconel 718. Experimental data, in both Conventional and High Pressure Coolant (HPC environments, are set in four different states depending on materials grain size and Hard-ness (LGA, LGS, SGA and SGS. Results reveal that PCA method is useful for visualization of the process and detection of anomalies in online processes.

  20. Recrystallization of the ODS superalloy PM-1000

    International Nuclear Information System (INIS)

    Sandim, H.R.Z.; Hayama, A.O.F.; Raabe, D.

    2006-01-01

    The primary recrystallization of a -fiber textured coarse-grained oxide dispersion strengthened nickel-based superalloy (PM-1000) has been investigated by high-resolution electron backscatter diffraction. The annealing behavior of this alloy is quite complex. Even at high annealing temperatures (e.g. 1200 deg. C), recrystallization is only partial. The microstructure of this superalloy in the annealed state consists of a blurred subgrain structure, coarse grains with sizes of about 10-20 μm at the pre-existing grain boundaries and a significant fraction of small crystals in the interior of the recovered grains. These small grains are elongated and display anisotropic growth. In the present paper we present a detailed explanation for this peculiar microstructure. Particular focus is placed on the origin of the new grains in the recovered structure in a [1 0 0]-oriented grain

  1. Development of Wrought Superalloy in China

    Directory of Open Access Journals (Sweden)

    DU Jinhui

    2016-06-01

    Full Text Available Wrought superalloy development in China was reviewed in recent ten years. The achievement of basic research and development of industrial manufacture technologies were systematically described from the aspects of new alloys, new technologies of hot deformation. New alloys include: new disc materials 718Plus, GH4720Li and GH4065 alloy, combustion chamber alloy GH3230, and GH4706 alloy for gas turbine engines. New technologies include: ERS-CDS new technology of easy segregation materials, multi upsetting-drawing for improving the microstructure uniformity of bars, slow cooling and multi-cycle thermomechanical treatment for increasing hot plasticity of hard-to-work alloys. Finally, the further development of wrought superalloys was prospected.

  2. Initial Mechanical Testing of Superalloy Lattice Block Structures Conducted

    Science.gov (United States)

    Krause, David L.; Whittenberger, J. Daniel

    2002-01-01

    The first mechanical tests of superalloy lattice block structures produced promising results for this exciting new lightweight material system. The testing was performed in-house at NASA Glenn Research Center's Structural Benchmark Test Facility, where small subelement-sized compression and beam specimens were loaded to observe elastic and plastic behavior, component strength levels, and fatigue resistance for hundreds of thousands of load cycles. Current lattice block construction produces a flat panel composed of thin ligaments arranged in a three-dimensional triangulated trusslike structure. Investment casting of lattice block panels has been developed and greatly expands opportunities for using this unique architecture in today's high-performance structures. In addition, advances made in NASA's Ultra-Efficient Engine Technology Program have extended the lattice block concept to superalloy materials. After a series of casting iterations, the nickel-based superalloy Inconel 718 (IN 718, Inco Alloys International, Inc., Huntington, WV) was successfully cast into lattice block panels; this combination offers light weight combined with high strength, high stiffness, and elevated-temperature durability. For tests to evaluate casting quality and configuration merit, small structural compression and bend test specimens were machined from the 5- by 12- by 0.5-in. panels. Linear elastic finite element analyses were completed for several specimen layouts to predict material stresses and deflections under proposed test conditions. The structural specimens were then subjected to room-temperature static and cyclic loads in Glenn's Life Prediction Branch's material test machine. Surprisingly, the test results exceeded analytical predictions: plastic strains greater than 5 percent were obtained, and fatigue lives did not depreciate relative to the base material. These assets were due to the formation of plastic hinges and the redundancies inherent in lattice block construction

  3. RA Reactor operation and maintenance (I-IX), part VI, Task 3.08/04, Refurbishment of the RA reactor; Pogon i odrzavanje reaktora (I-IX), VI Deo, Zadatak 3.08/04 Remont reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Zecevic, V [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    During the period planned for maintenance and refurbishment of the RA reactor the gas reactor system including the ventilation system was inspected and tested, the components were cleaned. This report describes detailed instructions and actions concerning repair and decontamination of the gas and ventilation systems components.

  4. Effects of helium impurities on superalloys

    International Nuclear Information System (INIS)

    Selle, J.E.

    1977-07-01

    A review of the literature on the effects of helium impurities on superalloys at elevated temperatures was undertaken. The actual effects of these impurities vary depending on the alloy, composition of the gas atmosphere, and temperature. In general, exposure in helium produces significant but not catastrophic changes in the structure and properties of the alloys. The effects of these treatments on the structure, creep, fatigue, and mechanical properties of the various alloys are reviewed and discussed. Suggestions for future work are presented

  5. Thermomechanical fatigue in single crystal superalloys

    Directory of Open Access Journals (Sweden)

    Moverare Johan J.

    2014-01-01

    Full Text Available Thermomechanical fatigue (TMF is a mechanism of deformation which is growing in importance due to the efficiency of modern cooling systems and the manner in which turbines and associated turbomachinery are now being operated. Unfortunately, at the present time, relatively little research has been carried out particularly on TMF of single crystal (SX superalloys, probably because the testing is significantly more challenging than the more standard creep and low cycle fatigue (LCF cases; the scarcity and relative expense of the material are additional factors. In this paper, the authors summarise their experiences on the TMF testing of SX superalloys, built up over several years. Emphasis is placed upon describing: (i the nature of the testing method, the challenges involved in ensuring that an given testing methodology is representative of engine conditions (ii the behaviour of a typical Re-containing second generation alloy such as CMSX-4, and its differing performance in out-of-phase/in-phase loading and crystallographic orientation and (iii the differences in behaviour displayed by the Re-containing alloys and new Re-free variants such as STAL15. It is demonstrated that the Re-containing superalloys are prone to different degradation mechanisms involving for example microtwinning, TCP precipitation and recrystallisation. The performance of STAL15 is not too inferior to alloys such as CMSX-4, suggesting that creep resistance itself does not correlate strongly with resistance to TMF. The implications for alloy design efforts are discussed.

  6. 75 FR 67100 - Superalloy Degassed Chromium From Japan

    Science.gov (United States)

    2010-11-01

    ... Chromium From Japan AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty order on superalloy degassed chromium from Japan. SUMMARY... order on superalloy degassed chromium from Japan would be likely to lead to continuation or recurrence...

  7. 76 FR 8773 - Superalloy Degassed Chromium From Japan

    Science.gov (United States)

    2011-02-15

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-1090 (Review)] Superalloy Degassed Chromium From Japan AGENCY: United States International Trade Commission. ACTION: Termination of five-year... revocation of the antidumping duty order on superalloy degassed chromium from Japan would be likely to lead...

  8. Refurbishment of a Victorian terraced house for energy efficiency

    Science.gov (United States)

    Dimitriou, Angeliki

    The impacts of global warming are now obvious. The international community has committed itself to reduce CO2 emissions, the main contributor to the greenhouse effect, both at international and national levels. In the Kyoto Protocol signed in 1997, countries have committed to reduce their greenhouse gases emissions below their 1990 levels by the period 2008-2012. The UK specifically should reduce those emissions by 12.5%. Format reason, the UK has introduced a package of policies, which promote not only the use of renewable energy resources, but most importantly the reduction in energy use, with energy efficiency. Refurbishment of existing houses has and will contribute to the reduction of energy consumption. A Victorian mid-terraced house was studied in this report, and different refurbishment measures were tested, using two software programmes: TAS and SAP. The targets were to achieve certain levels of thermal comfort, to comply with the Building Regulation for building thermal elements and to achieve a high SAP rating. Then, the cost of each measure was calculated and its CO2 emissions were compared. Heat losses were mainly through the walls and roof. Roof and mainly wall refurbishment measures reduce the heating loads the most. Ground floor insulation does not contribute to the reduction of the heating loads, on the contrary it has detrimental effect in summer, where the cooling effect coming from the ground is being reduced. Window replacement achieves a very good performance in summer resulting in the reduction of overheating. Wall and roof insulation increase the SAP rating the most, between the building elements, but boiler replacement and upgrading of heating controls increase it more. According to the SAP rating, CO2 annual emissions are reduced the most by boiler replacement and then by wall and roof. The results given by the two softwares concerning which measure is more leads more to energy efficiency, are the same. Finally, if the measures which lead

  9. Life extension studies and refurbishing of C and I systems of Cirus

    International Nuclear Information System (INIS)

    Awale, P.K.; Sumanth, P.; Roy, Kallol; Bharadwaj, G.

    2005-01-01

    Effects of ageing and component obsolescence of C and I systems of Cirus has been studied, by classifying the C and I systems as (a) those which may affect the operating life of the plant and cannot be repaired/replaced without core-unloading and dismantling the reactor structure. (Group-A), (b) those components which can be repaired/replaced but with considerable difficulty (Group-B) and (c) those which do not affect plant operations and can be easily repaired or replaced (Group-C). Life extension studies included performance assessment, reliability centred evaluation, parametric deviations from base-line characteristics and identification of specific ageing phenomenon and examination of internals. Based on these studies a comprehensive ageing mitigation programme was evolved, necessitating suitable modifications, instrumentation upgradation and component repair/replacement. A major modification job has been to provide an alternate failed fuel detection (FFD) system, since the success rate of the present system, had been decreasing over the years. Further, taking advantage of the available refurbishing outage, a number of instruments and accessories, pertaining to Group-C, were also replaced with state-of-the-art, components. Consideration is also given to requirements of special reactor start-up instrumentation for sensing the initial low neutron count in presence of a high gamma background, during the ensuing reactor start-up with fresh fuel. (author)

  10. Refurbishment and extension of the terrace of Restaurant No.1

    CERN Multimedia

    2009-01-01

    Work to refurbish and extend part of the terrace of Restaurant No.1 started in the first week of October and should last about two months. This is just a small part of the wide-ranging site infrastructure consolidation programme that began in April 2009. The new terrace, covering a surface area of 1770 m2 (compared with 1650 m2 today), is scheduled to be completed by the end of 2010 and will run all the way around the Restaurant No.1 extension. Work on the latter will affect part of Building 501 during the period from April to October 2010. The new dining room will seat some 275 additional customers (see picture). Part of the Cedars car-park will remain closed until some time in December to provide site access for trucks transporting construction materials, plant, etc. CERN Bulletin

  11. Fuel management during Cirus refurbishing and re-commissioning

    International Nuclear Information System (INIS)

    Rai, K.K.; Srivastava, Alok; Ramesh, N.; Sharma, R.C.

    2006-01-01

    Cirus is a Heavy water moderated and Demineralised water cooled 40 MW(th) research reactor. Graphite is used as reflector. Natural uranium in metallic form and clad in aluminium is used as fuel. After over three decades of operation, signs of ageing started surfacing up. Refurbishment plan was drawn up based upon ageing studies and performance review. Core unloading was the foremost requirement for jobs like assessment of integrity of primary coolant underground pipelines. Refuelling is carried out during reactor shut down with primary coolant pumps in operation. During the fuel unloading with the gradual removal of assemblies, reduction in the gross flow of primary coolant was also envisaged. The scheme for core unloading was formulated with emphasis on optimization of fuel utilization, cooling to the fuel assemblies during transit and overall safety of equipment and personnel. After completion of refurbishing jobs, it was decided to install dummy assemblies in pile to facilitate commissioning of primary coolant system. A lot of difficulty was faced due to release of iron oxide flakes from the surface of primary coolant pipelines. The inlet feeders, valves and dummy assemblies had to be periodically flushed to get rid of iron oxide flakes deposited during the period. Various efforts made to get rid of iron oxide flakes included increasing the velocity by bypassing the core, installation of hollow dummy assemblies and installation of strainer at core inlet. The decision of fuel loading was made based upon the experience feedback with dummy assemblies and assessment of the pattern of release of iron oxide flakes. The dummy assemblies were replaced with uranium fuel assemblies. Fuelling work was carried out with Reactor hall crane with additional precautions. This paper describes the experience with handling of irradiated fuel assemblies to facilitate core unloading, experience with dummy assemblies and loading of fuel into the core and subsequent performance

  12. Abnormal flow behavior and necklace microstructure of powder metallurgy superalloys with previous particle boundaries (PPBs)

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Yongquan, E-mail: luckyning@nwpu.edu.cn [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Zhou, Cong; Liang, Houquan [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Fu, M.W., E-mail: mmmwfu@polyu.edu.hk [Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)

    2016-01-15

    Powder metallurgy (P/M) has been introduced as an innovative process to manufacture high performance components with fine, homogenous and segregation-free microstructure. Unfortunately, previous particle boundary (PPB) precipitated during the powder metallurgy process. Since undesirable PPB is detrimental to mechanical properties, hot extrusion or/and isothermal forging are needed. In present research, isothermal compression tests were conducted on P/M FGH4096 superalloys with typical PPBs. Abnormal flow behavior during high-speed deformation has been quantitatively investigated. Caused by the competition mechanism between work-hardening and dynamic-softening, abnormal flow behaves typical four stages (viz., work-hardening, stable, softening and steady). Microstructure observation for hardening or/and softening mechanism has been investigated. Meanwhile, necklace microstructure was observed by scanning electron microscope, and the grain fraction analysis was performed by using electron backscatter diffraction. Transmission electron microscopy was used for characterizing the boundary structure. Necklace microstructural mechanism for processing P/M superalloys has been developed, and the dynamic recrystallization model has also been conducted. Bulge–corrugation model is the primary nucleation mechanism for P/M superalloys with PPBs. When PPB is entirely covered with new grains, necklace microstructure has formed. Bulge–corrugation mechanism can repeatedly take place in the following necklace DRX.

  13. Welding Metallurgy of Nickel-Based Superalloys for Power Plant Construction

    Science.gov (United States)

    Tung, David C.

    Increasing the steam temperature and pressure in coal-fired power plants is a perpetual goal driven by the pursuit of increasing thermal cycle efficiency and reducing fuel consumption and emissions. The next target steam operating conditions, which are 760°C (1400°F) and 35 MPa (5000 psi) are known as Advanced Ultra Supercritical (AUSC), and can reduce CO2 emissions up to 13% but this cannot be achieved with traditional power plant construction materials. The use of precipitation-strengthened Nickel-based alloys (superalloys) is required for components which will experience the highest operating temperatures. The leading candidate superalloys for power plant construction are alloys 740H, 282, and 617. Superalloys have excellent elevated temperature properties due to careful microstructural design which is achieved through very specific heat treatments, often requiring solution annealing or homogenization at temperatures of 1100 °C or higher. A series of postweld heat treatments was investigated and it was found that homogenization steps before aging had no noticeable effect on weld metal microhardness, however; there were clear improvements in weld metal homogeneity. The full abstract can be viewed in the document itself.

  14. High Temperature Deformation Mechanisms in a DLD Nickel Superalloy

    Directory of Open Access Journals (Sweden)

    Sean Davies

    2017-04-01

    Full Text Available The realisation of employing Additive Layer Manufacturing (ALM technologies to produce components in the aerospace industry is significantly increasing. This can be attributed to their ability to offer the near-net shape fabrication of fully dense components with a high potential for geometrical optimisation, all of which contribute to subsequent reductions in material wastage and component weight. However, the influence of this manufacturing route on the properties of aerospace alloys must first be fully understood before being actively applied in-service. Specimens from the nickel superalloy C263 have been manufactured using Powder Bed Direct Laser Deposition (PB-DLD, each with unique post-processing conditions. These variables include two build orientations, vertical and horizontal, and two different heat treatments. The effects of build orientation and post-process heat treatments on the materials’ mechanical properties have been assessed with the Small Punch Tensile (SPT test technique, a practical test method given the limited availability of PB-DLD consolidated material. SPT testing was also conducted on a cast C263 variant to compare with PB-DLD derivatives. At both room and elevated temperature conditions, differences in mechanical performances arose between each material variant. This was found to be instigated by microstructural variations exposed through microscopic and Energy Dispersive X-ray Spectroscopy (EDS analysis. SPT results were also compared with available uniaxial tensile data in terms of SPT peak and yield load against uniaxial ultimate tensile and yield strength.

  15. Low-Cobalt Powder-Metallurgy Superalloy

    Science.gov (United States)

    Harf, F. H.

    1986-01-01

    Highly-stressed jet-engine parts made with less cobalt. Udimet 700* (or equivalent) is common nickel-based superalloy used in hot sections of jet engines for many years. This alloy, while normally used in wrought condition, also gas-atomized into prealloyed powder-metallurgy (PM) product. Product can be consolidated by hot isostatically pressing (HIPPM condition) and formed into parts such as turbine disk. Such jet-engine disks "see" both high stresses and temperatures to 1,400 degrees F (760 degrees C).

  16. Mechanical characterization of superalloys for space reactors

    International Nuclear Information System (INIS)

    Duchesne, J.

    1989-01-01

    The aim of this work is the selection of structural materials that can be used in the temperature range 600-900 0 C for a gas cooled space reactor producing electricity. Superalloys fit best the temperature range required. Five nickel base alloys are chosen for their good mechanical behaviour: HAYNES 230, HASTELLOY S, HASTELLOY X, HASTELLOY XR and PYRAD 38D. Metallography, tensile and hardness tests are realized. Sample contraction is evidenced for some creep tests, under low stress: 20MPa at 800 0 C, on HAYNES 230 and HASTELLOY X, probably related to the structural evolution of these materials corresponding to a decrease of the crystal parameter [fr

  17. The NNR requirements to address modification, modernization, refurbishment and ageing management

    International Nuclear Information System (INIS)

    Thugwane, Samuel

    2013-01-01

    The National Nuclear Regulator (NNR) is a national competent authority in South African which has been mandated under Act 47 of 1999 to provide for the protection of property people and environment. The NNR achieves its mandated by issuing Nuclear Authorisations in case of Nuclear Installations and Certificate of registration for the mining industry. Currently SAFARI-1 Research Reactor at Pelindaba site is the only Research Reactor that is licensed by NNR through a Process based licensing. SAFARI-1 is a 20 MW research reactor and has been in operation since 1965 and is approaching its full lifetime. Regular, periodic and systematic examination, inspection, maintenance and testing of all plant, systems, structures and components have been developed and implemented. Modification and refurbishment has been implemented over years since its construction. Ageing of structural components and obsolescence is now becoming a challenge; as a result, Ageing Management Programme has been developed to address these issues. In accordance with the NNR requirements any modification that the licensee plan to implement, must comply with NNR approved processes and procedures relating to control of such modification to the design of existing plant, facility or system design, including modifications that may be of a temporary nature

  18. The NNR requirements to address modification, modernization, refurbishment and ageing management

    Energy Technology Data Exchange (ETDEWEB)

    Thugwane, Samuel [National Nuclear Regulator, Pretoria (South Africa)

    2013-07-01

    The National Nuclear Regulator (NNR) is a national competent authority in South African which has been mandated under Act 47 of 1999 to provide for the protection of property people and environment. The NNR achieves its mandated by issuing Nuclear Authorisations in case of Nuclear Installations and Certificate of registration for the mining industry. Currently SAFARI-1 Research Reactor at Pelindaba site is the only Research Reactor that is licensed by NNR through a Process based licensing. SAFARI-1 is a 20 MW research reactor and has been in operation since 1965 and is approaching its full lifetime. Regular, periodic and systematic examination, inspection, maintenance and testing of all plant, systems, structures and components have been developed and implemented. Modification and refurbishment has been implemented over years since its construction. Ageing of structural components and obsolescence is now becoming a challenge; as a result, Ageing Management Programme has been developed to address these issues. In accordance with the NNR requirements any modification that the licensee plan to implement, must comply with NNR approved processes and procedures relating to control of such modification to the design of existing plant, facility or system design, including modifications that may be of a temporary nature.

  19. Ongoing refurbishment activities and strategy for the future operation of the BR2 reactor

    International Nuclear Information System (INIS)

    Koonen, E.; Gubel, P.

    1994-01-01

    The operation of the BR2 reactor with its second Be-matrix is foreseen up to mid-1995 or mid-1996. A life extension for another 15 years is envisaged considering programmatic, financial and technical aspects. At present, the second phase of the refurbishment programme is being executed. The major activities of this programme can be grouped under two headings: safety reassessment and ageing issues. The expected outcome end '93 is an assessment report defining extent, choosen options, prioritized activities, budget and a tentative planning for the preparation and execution of the refurbishment. These aspects together with the prospects of possible cooperation with other parties for the refurbishment programme and the future operation of BR2 will be evaluated by the CEN/SCK Board who has to take a decision early in 1994. Various scenarios are now being considered and evaluated for the refurbishment and the future BR2 operation regime. (author)

  20. Ongoing refurbishment activities and strategy for the future operation of the BR2 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Koonen, E; Gubel, P [BR2 Department, Belgian Nuclear Research Center, CEN/SCK, Mol (Belgium)

    1993-07-01

    The operation of the BR2 reactor with its second Be-matrix is foreseen up to mid-1995 or mid-1996. A life extension for another 15 years is envisaged considering programmatic, financial and technical aspects. At present, the second phase of the refurbishment programme is being executed. The major activities of this programme can be grouped under two headings: safety reassessment and ageing issues. The expected outcome end '93 is an assessment report defining extent, choosen options, prioritized activities, budget and a tentative planning for the preparation and execution of the refurbishment. These aspects together with the prospects of possible cooperation with other parties for the refurbishment programme and the future operation of BR2 will be evaluated by the CEN/SCK Board who has to take a decision early in 1994. Various scenarios are now being considered and evaluated for the refurbishment and the future BR2 operation regime. (author)

  1. The influences of attributes, skills and knowledge of managers on refurbishment project performance

    Science.gov (United States)

    Ishak, Nurfadzillah

    2018-02-01

    Recently, the momentum on the growth of national building industry shows the increasing of the demand in refurbishment works becomes a trend spreading over the Malaysia. However, the potential of these activities normally related with the complexity in technical aspect compared to new build schemes. It will be reflecting on the unsatisfactory project performance. A competent manager is required to have the appropriate attributes, skills and knowledge in able to perform all the duties associated with managing the refurbishment building projects. Therefore, this paper is to identify the most appropriate attributes, skills and knowledge that required for managers to indicate the relationship between the influences on the refurbishment projects performance. This finding is indicate the importance of development the personal attributes, skills, and knowledge of managers and adds as benefit of raising the profile and image of managers in refurbishment building industry through a dissemination of the findings.

  2. Ongoing refurbishment activities and strategy for the future operation of the BR2 reactor

    International Nuclear Information System (INIS)

    Koonen, E.; Gubel, P.

    1993-01-01

    The operation of the BR2 reactor with its second Be-matrix is foreseen up to mid-1995 or mid-1996. A life extension for another 15 years is envisaged considering programmatic, financial and technical aspects. At present, the second phase of the refurbishment programme is being executed. The major activities of this programme can be grouped under two headings: safety reassessment and ageing issues. The expected outcome end '93 is an assessment report defining extent, choosen options, prioritized activities, budget and a tentative planning for the preparation and execution of the refurbishment. These aspects together with the prospects of possible cooperation with other parties for the refurbishment programme and the future operation of BR2 will be evaluated by the CEN/SCK Board who has to take a decision early in 1994. Various scenarios are now being considered and evaluated for the refurbishment and the future BR2 operation regime. (author)

  3. Refurbishment, core conversion and safety analysis of Apsara reactor

    Energy Technology Data Exchange (ETDEWEB)

    Raina, V.K.; Sasidharan, K.; Sengupta, S. [Bhabha Atomic Research Centre, Mumbai (India)]. E-mail: nram@@apsara.barc.ernet.in

    1998-07-01

    Apsara, a 1 MWt pool type reactor using HEU fuel has been in operation at the Bhabha Atomic Research Centre, Trombay since 1956. In view of the long service period seen by the reactor it is now planned to carry out extensive refurbishment of the reactor with a view to extend its useful life. It is also proposed to modify the design of the reactor wherein the core will be surrounded by a heavy water reflector tank to obtain a good thermal neutron flux over a large radial distance from the core. Beam holes and the majority of the irradiation facilities will be located inside the reflector tank. The coolant flow direction through the core will be changed from the existing upward flow to downward flow. A delay tank, located inside the pool, is provided to facilitate decay of short lived radioactivity in the coolant outlet from the core in order to bring down radiation field in the operating areas. Analysis of various anticipated operational occurrences and accident conditions like loss of normal power, core coolant flow bypass, fuel channel blockage and degradation of primary coolant pressure boundary have been performed for the proposed design. Details of the proposed design modifications and the safety analyses are given in the paper. (author)

  4. Acoustical qualification of Teatro Nuovo in Spoleto before refurbishing works

    Science.gov (United States)

    Cocchi, Alessandro; Cesare Consumi, Marco; Shimokura, Ryota

    2004-05-01

    To qualify the acoustical quality of an opera house two different approaches are now available: one is based on responses of qualified listeners (subjective judgments) compared with objective values of selected parameters, the other on comparison tests conducted in suited rooms and on a model of the auditory brain system (preference). In the occasion of the refurbishment of an opera house known for the Two Worlds Festival edited yearly by the Italian Composer G. C. Menotti, a large number of measurements were taken with different techniques, so it is possible to compare the different methods and also the results with some geometrical criterion, based on the most simple rules of musical harmony, now neglected as our attention is attracted to computer simulations, computer aided measurement techniques and similar modern methods. From this work some link between well known acoustical parameters (not known at the time when architects sketched the shape of ancient opera houses) and geometrical criteria (well known at the time when ancient opera houses were built) will be shown.

  5. Technological energy and environmental refurbishment of historical Italian libraries

    Directory of Open Access Journals (Sweden)

    Alessandra Battisti

    2014-10-01

    Full Text Available Active libraries in Italy are around 13.000 and, taken as a whole, the property and management relate mainly to public institutions such as the state, regions, local authorities, cultural institutions, universities, and partly to religious institutions and individuals. In this paper is presented the work of studies and research, commissioned to the authors by the General Direction for Libraries of the Ministry of Heritage and Culture (Mibac, which ended recently, addressing the architectural, energy and environmental refurbishment of national historic libraries distributed on the Italian territory, with special focus on 4 among 46 owned by the Ministry of Culture (the Nazionale Centrale di Roma, the Nazionale Centrale in Florence, the national University of Turin and the Angelica in Rome believed by the authors and client as examples of recurring issues and ideals to lend itself to the construction of a model of intervention replicable on other historical Italian libraries.The main objective of the project is the identification of physical and perceptual factors of wear2, which threaten the conservation of the historical and artistic heritage of the historic center of Venice, with a particular focus on the effects of anthropogenic pressure linked to tourism, and the evaluation of their level of danger. A further objective is the recognition of measurable parameters (indicators for monitoring and, subsequently, mitigation strategies for the most significant phenomena.

  6. Modernization and Refurbishment of the RECH-1 Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Daie, J. [Nuclear Application Department, Chilean Nuclear Energy Commission (CCHEN), Santiago (Chile)

    2014-08-15

    The Chilean Nuclear Energy Commission (Comisión Chilena de Energía Nuclear, or CCHEN) has operated the RECH-1 research reactor since 1974. This reactor is located at La Reina Nuclear Centre in Santiago, Chile. It is a pool type reactor using LEU MTR fuel assemblies, light water as moderator and coolant, and beryllium as reflector. The reactor has been operated at the nominal power of 5 MW in a continuous shift of 20 hours per week, 48 weeks per year. The main utilizations of the RECH-1 reactor are radioisotope production and neutron activation analysis. Among the most relevant refurbishment and modernization campaigns undertaken at the reactor are: full core conversion to the use of LEU fuel, replacement of the cooling tower, improvement of the containment building by changing the doors and gates and by a better sealant for the penetrations, introduction of an additional source of water by connecting the raw water supply system to the emergency cooling system, improvement of the emergency ventilation system, introduction of a fire detection and alarm system for detection and mitigation to protect the I&C racks, introduction of a radioactive liquid release for those generated at the reactor, introduction of a delay tank degasification system and renewal of the environmental monitoring system. At present we are assessing the possibility of replacing the old analog electronics of control for new digital systems. Detailed descriptions of these diverse activities are presented in the paper. (author)

  7. Proceedings of the Conference on Refractory Alloying Elements in Superalloys

    International Nuclear Information System (INIS)

    1984-01-01

    Some papers about the use of refractory metals in superalloys are presented. Mechanical properties, thermodynamics properties, use for nuclear fuels and corrosion resistance of those alloys are studied. (E.G.) [pt

  8. Grinding of Inconel 713 superalloy for gas turbines

    Czech Academy of Sciences Publication Activity Database

    Čapek, J.; Kyncl, J.; Kolařík, K.; Beránek, L.; Pitrmuc, Z.; Medřický, Jan; Pala, Z.

    2016-01-01

    Roč. 16, č. 1 (2016), s. 14-15 ISSN 1213-2489 Institutional support: RVO:61389021 Keywords : Casting defects * Gas turbine * Grinding * Nickel superalloy * Residual stresses Subject RIV: JJ - Other Materials

  9. A high-throughput search for new ternary superalloys

    Science.gov (United States)

    Nyshadham, Chandramouli; Hansen, Jacob; Oses, Corey; Curtarolo, Stefano; Hart, Gus

    In 2006 an unexpected new superalloy, Co3[Al,W], was discovered. This new alloy is cobalt-based, in contrast to conventional superalloys, which are nickel-based. Inspired by this new discovery, we performed first-principles calculations, searching through 2224 ternary metallic systems of the form A3[B0.5C0.5], where A = Ni/Co/Fe and [B, C] = all binary combinations of 40 different elements chosen from the periodic table. We found 175 new systems that are better than the Co3[Al, W] superalloy. 75 of these systems are brand new--they have never been reported in experimental literature. These 75 new potential superalloys are good candidates for further experiments. Our calculations are consistent with current experimental literature where data exists. Work supported under: ONR (MURI N00014-13-1-0635).

  10. Energy Efficiency Performance in Refurbishment Projects with Design Team Attributes As A Mediator: A Pilot Study

    Science.gov (United States)

    Sekak, Siti Nor Azniza Ahmad; Rahmat Dr, Ismail, Prof.; Yunus, Julitta; Saád, Sri Rahayu Mohd; Hanafi Azman Ong, Mohd

    2017-12-01

    The Energy Efficiency (EE) plays an important role over the building life cycle and the implementation of EE in refurbishment projects has a significant potential towards the reduction of greenhouse gas emissions. However, the involvement of the design team at the early stage of the refurbishment projects will determine the success of EE implementations. Thus, a pilot study was conducted at the initial stage of the data collection process of this research to validate and verify the questionnaires.

  11. Home-made refurbishment of the instrumentation and control system of the TRIGA reactor of the University of Pavia

    International Nuclear Information System (INIS)

    Borio di Tigliole, A.; Cagnazzo, M.; Magrotti, G.; Manera, S.; Salvini, A.; Musitelli, G.; Nardo, R.

    2008-01-01

    The Instrumentation and Control (I and C) System of the TRIGA reactor of the University of Pavia was dated and, in order to grant a safe and continuous reactor operation for the future, it became necessary to substitute or to upgrade the system. Since the substitution of the I and C system with a new-made one was very difficult to be performed due to long authorization procedures, an home-made refurbishment was planned. Using commercial components of high quality, almost a complete substitution, channel-by-channel, of the I and C system was realized without changing the operating and safety logics. The system includes: - the Reactor Linear Power Channel and Chart Recorder; - the Reactor Percent Power Safety Channel; - the High Voltage and Low Voltage Power Supply; - the Automatic Reactor Power Control; - the Fuel Elements and Cooling-Water Temperatures Measuring Channels; - the Water Conductivity Measuring Channel. The refurbished I and C system shows a very good operational behavior and reliability and will assure a continuous operation of the reactor for the future

  12. Effect of Crystal Orientation on Fatigue Failure of Single Crystal Nickel Base Turbine Blade Superalloys

    Science.gov (United States)

    Arakere, Nagaraj K.; Swanson, Gregory R.

    2000-01-01

    High Cycle Fatigue (HCF) induced failures in aircraft gas-turbine engines is a pervasive problem affecting a wide range of components and materials. HCF is currently the primary cause of component failures in gas turbine aircraft engines. Turbine blades in high performance aircraft and rocket engines are increasingly being made of single crystal nickel superalloys. Single-crystal Nickel-base superalloys were developed to provide superior creep, stress rupture, melt resistance and thermomechanical fatigue capabilities over polycrystalline alloys previously used in the production of turbine blades and vanes. Currently the most widely used single crystal turbine blade superalloys are PWA 1480/1493 and PWA 1484. These alloys play an important role in commercial, military and space propulsion systems. PWA1493, identical to PWA1480, but with tighter chemical constituent control, is used in the NASA SSME (Space Shuttle Main Engine) alternate turbopump, a liquid hydrogen fueled rocket engine. Objectives for this paper are motivated by the need for developing failure criteria and fatigue life evaluation procedures for high temperature single crystal components, using available fatigue data and finite element modeling of turbine blades. Using the FE (finite element) stress analysis results and the fatigue life relations developed, the effect of variation of primary and secondary crystal orientations on life is determined, at critical blade locations. The most advantageous crystal orientation for a given blade design is determined. Results presented demonstrates that control of secondary and primary crystallographic orientation has the potential to optimize blade design by increasing its resistance to fatigue crack growth without adding additional weight or cost.

  13. A State of the Art Report on the Case Study of Hot Cell Decontamination and Refurbishment

    Energy Technology Data Exchange (ETDEWEB)

    Won, H. J.; Jung, C. H.; Moon, J. K.; Park, G. I.; Song, K. C

    2008-08-15

    As the increase of the operation age of the domestic high radiation facilities such as IMEF, PIEF and DFDF, the necessity of decontamination and refurbishment of hot cells in these facilities is also increased. In the near future, the possibilities of refurbishment of hot cells in compliance with the new regulations, the reuse of hot cells for the other purposes and the decommissioning of the facilities also exist. To prepare against the decontamination and refurbishment of hot cells, the reports on the refurbishment, decommissioning and decontamination experiences of hot cells in USA, Japan, France, Belgium and Great Britain were investigated. ANL of USA performed the project on the decontamination of hot cells. The purpose of the project was to practically eliminate the radioactive emissions of Rn-220 to the environment and to restore the hot cells to an empty restricted use condition. The five hot cells were emptied and decontaminated for restricted use. Chemical processing facility in JAEA of Japan was used for the reprocessing study of spent fuels, hot cells in CPF were refurbished from 1995 for the tests of the newly developed reprocessing process. In a first stage, decommissioning and decontamination were fully performed by the remote operation Then, decommissioning and decontamination were performed manually. By the newly developed process, they reported that the radiation exposure of workers were satisfactorily reduced. In the other countries, they also make an effort for the refurbishment and decontamination of hot cells and it is inferred that they accumulate experiences in these fields.

  14. Low temperature gaseous nitriding of Ni based superalloys

    DEFF Research Database (Denmark)

    Eliasen, K. M.; Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2010-01-01

    In the present work the nitriding response of selected Ni based superalloys at low temperatures is addressed. The alloys investigated are nimonic series nos. 80, 90, 95 and 100 and nichrome (Ni/Cr......In the present work the nitriding response of selected Ni based superalloys at low temperatures is addressed. The alloys investigated are nimonic series nos. 80, 90, 95 and 100 and nichrome (Ni/Cr...

  15. Development of a Refractory High Entropy Superalloy (Postprint)

    Science.gov (United States)

    2016-03-17

    hardened with HfC precipitates [2], Co-Re- or Co-Al-W-based alloys [3] or two-phase ( FCC + L12) refractory superalloys based on platinum group metals...Ni-based superalloys consisting of cuboids with the ordered L12 structure embedded in an FCC solid-solution matrix. Based on this microstructural...and 5). A comparison of the average atomic radii with the measured lattice parameters allows us to conclude that the disordered BCC phase forming

  16. Changes in the properties of superalloys by long term heating

    International Nuclear Information System (INIS)

    Susukida, H.; Tsuji, I.; Kawai, H.

    1976-01-01

    A laboratory study was conducted in order to determine the effect of long term heating (max. 10000h at 850 0 and 950 0 C) on the microstructure, tensile properties, hardness and stress rupture properties of four kinds of superalloys. These superalloys are two kinds of solid solution hardened Ni-base superalloys Hastelloy X and Inconel 617 and two kinds of dispersion strengthened Ni-base superalloys TD-Ni and TD-NiCr. The result of the study can be summarized as follows: (1) Solid solution hardened superalloys: Many precipitates were observed in the grains and on the grain boundaries after 100 hours of heating, and the precipitates became coarse-grained by over 1000 hours of heating. This tendency was remarkable when they were heated at 950 0 C. With the change of their microstructure, their mechanical properties also changed, particularly their tensile ductility decreased remarkably. (2) Dispersion strengthened superalloys: Their microstructure and mechanical properties were almost unchanged by long term heating. (3) The authors proposed ''solid solution hardening value'' in order to grasp quantitatively the solid solution hardening which has been discussed by the content of each element hitherto. (auth.)

  17. Homogenization Kinetics of a Nickel-based Superalloy Produced by Powder Bed Fusion Laser Sintering.

    Science.gov (United States)

    Zhang, Fan; Levine, Lyle E; Allen, Andrew J; Campbell, Carelyn E; Lass, Eric A; Cheruvathur, Sudha; Stoudt, Mark R; Williams, Maureen E; Idell, Yaakov

    2017-04-01

    Additively manufactured (AM) metal components often exhibit fine dendritic microstructures and elemental segregation due to the initial rapid solidification and subsequent melting and cooling during the build process, which without homogenization would adversely affect materials performance. In this letter, we report in situ observation of the homogenization kinetics of an AM nickel-based superalloy using synchrotron small angle X-ray scattering. The identified kinetic time scale is in good agreement with thermodynamic diffusion simulation predictions using microstructural dimensions acquired by ex situ scanning electron microscopy. These findings could serve as a recipe for predicting, observing, and validating homogenization treatments in AM materials.

  18. Saving money on rig refurbishments through foreign trade zones or duty-drawback

    International Nuclear Information System (INIS)

    Ward, R.J. Jr.

    1997-01-01

    The recent boom in day rates for rigs capable of drilling in deep water and harsh environments has created a frenzy of rig refurbishment activity in shipyards located in US Gulf states. In most instances, the destination for the rigs upon completion is the US Outer Continental Shelf (USOCS) in the Gulf of Mexico. The problem faced by contractors/operators planning to use US shipyards is that this circumstance has caused difficulty in shielding rigs and their foreign-sourced components from US Customs duties. Under US Customs law, a bona fide exportation requires severance from US commerce and joining to the commerce of some foreign country or, in the case of a vessel supply, a qualifying international voyage. The USOCS does not qualify as an exportation, nor do movements to drilling sites located on it qualify as an international voyage. Described here are two possible solutions to this economic dilemma and an example of how the foreign trade zone solution was applied by Global marine in its plans for upgrading some of its semisubmersible drilling rigs for deepwater USOCS work

  19. Segregation to grain boundaries in nimonic PE16 superalloy

    International Nuclear Information System (INIS)

    Nettleship, D.J.; Wild, R.K.

    1990-01-01

    Nimonic PE16 alloy is a nickel-based superalloy containing 34 wt.% iron and 16wt.% chromium with additions of molybdenum, titanium and aluminium. It is used in the fuel assembly of the UK advanced gas-cooled reactors (AGR). This component supports significant loads in service and its mechanical integrity is therefore of paramount importance. Mechanical properties may be influenced by the grain size and grain boundary composition, both of which can themselves alter during service. Scanning Auger microscopy is a well-established method for investigating grain boundaries, and has now been applied to the study of PE16. In order to expose PE16 grain boundary surfaces it is necessary to hydrogen charge samples and fracture by pulling in tension at a slow strain rate within the ultra-high vacuum chamber of the Auger microprobe. A series of casts of nimonic PE16 alloy that have received a range of thermal ageing treatments have been fractured in an intergranular manner and the grain boundary composition determined. Segregation of trace and minority elements, particularly Mo and P, has been detected at grain boundaries. Significant variations between different as-manufactured casts were observed, whilst ageing brought about the growth of chromium-rich particles on the grain boundaries. Ductile fracture in PE16 followed a path through Ti(C, N) particles. Many of these particles incorporated large amounts of sulphur. (author)

  20. ISOTHERMAL AND THERMOMECHANICAL FATIGUE OF A NICKEL-BASE SUPERALLOY

    Directory of Open Access Journals (Sweden)

    Carlos Carvalho Engler-Pinto Júnior

    2014-06-01

    Full Text Available Thermal gradients arising during transient regimes of start-up and shutdown operations produce a complex thermal and mechanical fatigue loading which limits the life of turbine blades and other engine components operating at high temperatures. More accurate and reliable assessment under non-isothermal fatigue becomes therefore mandatory. This paper investigates the nickel base superalloy CM 247LC-DS under isothermal low cycle fatigue (LCF and thermomechanical fatigue (TMF. Test temperatures range from 600°C to 1,000°C. The behavior of the alloy is strongly affected by the temperature variation, especially in the 800°C-1,000°C range. The Ramberg-Osgood equation fits very well the observed isothermal behavior for the whole temperature range. The simplified non-isothermal stress-strain model based on linear plasticity proposed to represent the thermo-mechanical fatigue behavior was able to reproduce the observed behavior for both in-phase and out-of-phase TMF cycling.

  1. Creep Behaviour of Modified Mar-247 Superalloy

    Directory of Open Access Journals (Sweden)

    Cieśla M.

    2016-06-01

    Full Text Available The paper presents the results of analysis of creep behaviour in short term creep tests of cast MAR-247 nickel-based superalloy samples made using various modification techniques and heat treatment. The accelerated creep tests were performed under temperature of 982 °C and the axial stresses of σ = 150 MPa (variant I and 200 MPa (variant II. The creep behaviour was analysed based on: creep durability (creep rupture life, steady-state creep rate and morphological parameters of macro- and microstructure. It was observed that the grain size determines the creep durability in case of test conditions used in variant I, durability of coarse-grained samples was significantly higher.

  2. Creep-fatigue of low cobalt superalloys

    Science.gov (United States)

    Halford, G. R.

    1982-01-01

    Testing for the low cycle fatigue and creep fatigue resistance of superalloys containing reduced amounts of cobalt is described. The test matrix employed involves a single high temperature appropriate for each alloy. A single total strain range, again appropriate to each alloy, is used in conducting strain controlled, low cycle, creep fatigue tests. The total strain range is based upon the level of straining that results in about 10,000 cycles to failure in a high frequency (0.5 Hz) continuous strain-cycling fatigue test. No creep is expected to occur in such a test. To bracket the influence of creep on the cyclic strain resistance, strain hold time tests with ore minute hold periods are introduced. One test per composition is conducted with the hold period in tension only, one in compression only, and one in both tension and compression. The test temperatures, alloys, and their cobalt compositions that are under study are given.

  3. Hydrogen Annealing Of Single-Crystal Superalloys

    Science.gov (United States)

    Smialek, James L.; Schaeffer, John C.; Murphy, Wendy

    1995-01-01

    Annealing at temperature equal to or greater than 2,200 degrees F in atmosphere of hydrogen found to increase ability of single-crystal superalloys to resist oxidation when subsequently exposed to oxidizing atmospheres at temperatures almost as high. Supperalloys in question are principal constituents of hot-stage airfoils (blades) in aircraft and ground-based turbine engines; also used in other high-temperature applications like chemical-processing plants, coal-gasification plants, petrochemical refineries, and boilers. Hydrogen anneal provides resistance to oxidation without decreasing fatigue strength and without need for coating or reactive sulfur-gettering constituents. In comparison with coating, hydrogen annealing costs less. Benefits extend to stainless steels, nickel/chromium, and nickel-base alloys, subject to same scale-adhesion and oxidation-resistance considerations, except that scale is chromia instead of alumina.

  4. Eddy Current Nondestructive Residual Stress Assessment in Shot-Peened Nickel-Base Superalloys

    International Nuclear Information System (INIS)

    Blodgett, M.P.; Yu, F.; Nagy, P.B.

    2005-01-01

    Shot peening and other mechanical surface enhancement methods improve the fatigue resistance and foreign-object damage tolerance of metallic components by introducing beneficial near-surface compressive residual stresses and hardening the surface. However, the fatigue life improvement gained via surface enhancement is not explicitly accounted for in current engine component life prediction models because of the lack of accurate and reliable nondestructive methods that could verify the presence of compressive near-surface residual stresses in shot-peened hardware. In light of its frequency-dependent penetration depth, the measurement of eddy current conductivity has been suggested as a possible means to allow the nondestructive evaluation of subsurface residual stresses in surface-treated components. This technique is based on the so-called piezoresistivity effect, i.e., the stress-dependence of electrical resistivity. We found that, in contrast with most other materials, surface-treated nickel-base superalloys exhibit an apparent increase in electrical conductivity at increasing inspection frequencies, i.e., at decreasing penetration depths. Experimental results are presented to illustrate that the excess frequency-dependent apparent eddy current conductivity of shot-peened nickel-base superalloys can be used to estimate the absolute level and penetration depth of the compressive residual stress layer both before and after partial thermal relaxation

  5. The impact of building orientation and discount rates on a Portuguese reference building refurbishment decision

    International Nuclear Information System (INIS)

    Brandão de Vasconcelos, Ana; Cabaço, António; Pinheiro, Manuel Duarte; Manso, Armando

    2016-01-01

    Refurbishment, as part of the construction industry, has a strong global impact, not only from the viewpoint of economies but also from social and energy-efficiency perspectives. A thermal refurbishment process, in particular, involves numerous decisions and choices; the decision-makers being ultimately confronted with two major questions: which criterion should be adopted in the choice of the refurbishment construction solutions and which refurbishment construction solutions should be chosen? In this paper, a criterion based on technical and economic points of view is proposed, aiming to identify the cost-optimal package of energy efficient solutions from among a set of possible refurbishment measures, within the life cycle of buildings. Sensitivity analyses are also performed so that the results may help the decision-maker choose the appropriate refurbishment solutions to be adopted when different discount rates and building orientations are taken into consideration. A total of seven scenarios, for a macroeconomic perspective, and nine, for a financial perspective, are performed. The costoptimal methodology adopted, following the Directive 2010/31/EU (2010) recommendations, is applied to a Portuguese reference building. The analysis carried out allows obtaining low global life cycle costs solutions and points towards nearly Zero Energy Building (nZEB) concept. The results are important for drawing national political instruments on buildings energy efficiency. - Highlights: •Building refurbishment decision based on technical and economic points of view. •35.000 Packages of thermal rehabilitation solutions considered. •Building orientation and discount rate impact on the cost-optimal package of solutions. •Portuguese reference building case base.

  6. The effects of acoustical refurbishment of classrooms on teachers’ perceived noise exposure and noise-related health symptoms

    DEFF Research Database (Denmark)

    Kristiansen, Jesper; Lund, Søren Peter; Persson, Roger

    2015-01-01

    lessons with circa 2 dB(A) in both schools. Conclusion: The acoustical refurbishment was associated with a reduction in classroom reverberation time and activity sound levels in both schools. The acoustical refurbishment was associated with a reduction in the teachers’ perceived noise exposure...... of RT and activity sound levels were measured before and after refurbishment. Data on perceived noise exposure, disturbance attributed to different noise sources, voice symptoms, and fatigue after work were collected over a year in a total of six consecutive questionnaires. Results: Refurbished......, the mean classroom reverberation time was 0.68 (school A) and 0.57 (school B) and 0.55 s in sham refurbished classrooms. After refurbishment, the RT was approximately 0.4 s in both schools. Activity sound level measurements confirmed that the intervention had reduced the equivalent sound levels during...

  7. Refurbishment programme of the reactor and progress of work

    International Nuclear Information System (INIS)

    Astruc, J.M.

    1992-01-01

    During 20 years of operation, since its start-up the ILL there have been some problems, like ruptured heavy water collector, in the upper part of the reflector tank, replacement of all the beam tubes due to the evolution of the mechanical characteristics of the aluminium alloy under irradiation. Some days after regular shutdown for maintenance, an inspection of the internal elements of the reactor discovered cracks on the grids which ensure the regular flow of cooling water. The investigations showed that the cracks are due to a design fault, aggravated by the effects of mechanical fatigue on highly irradiated material. It was not possible to repair the cracked grid, and it had to be replaced. This involved the dismantling of the internals parts of the reactor tank. The reactor refurbishment programme was set up. It provides for the replacement of the reactor block, the coupling sleeves, the anti turbulence grids and the diffuser, and of the ancillary elements. The main items to be replaced are: the reactor block consisting of the reactor vessel and its cover, known as the 'upper structure'; the heavy water collectors; connecting sleeves between the reactor block and the flanges of the various beam tubes. These three items constitute the primary circuit in the swimming pool. It is also planned to replace some internal parts of the reactor tank, such as the beam-tubes, the grid and diffuser and the chimney. Some parts of the present reactor, which are not at the end of their life, would be reused, for instance the two cold sources, the safety rods, and some other pieces. The parts replaced would be cut up and packaged in accordance with current standards and disposed of. All items are in principle to be replaced by identical equipment. This concerns in particular performance, mechanical characteristics and the choice of materials. The replacement of the reactor block necessitates a complete dismantling of the equipment in the reactor block, and of the structures in

  8. Coordination Devices in the Refurbishment Design Process: A Partial-Correlation Approach

    Directory of Open Access Journals (Sweden)

    Azlan Shah Ali

    2009-12-01

    Full Text Available Building refurbishment is an important sector in the Malaysian construction industry. The increase the number of building renovations, alterations, extensions and extensive repair works contributed to the high demand for refurbishment projects. However, refurbishment projects are more difficult to manage compared to new-built, due to uncertainty factors inherent in the projects. Therefore, this paper identifies factors that contributed to uncertainty and shows how it affects design performance of refurbishment projects. This paper was also extended to the used of coordination devices to improve design performance from the effect of uncertainty in the projects. Partial-correlation technique was used in data analysis to check any significant moderate effects of coordination devices to control the negative effect of uncertainty on design performance of refurbishment projects. Four (4 coordination devices involved in the partial-correlation tests. The results concluded that the use of lateral relations and architect’s characteristics are most likely reducing the uncertainty of client attributes towards design completeness before work started on site.

  9. Prediction of recrystallisation in single crystal nickel-based superalloys during investment casting

    Directory of Open Access Journals (Sweden)

    Panwisawas Chinnapat

    2014-01-01

    Full Text Available Production of gas turbines for jet propulsion and power generation requires the manufacture of turbine blades from single crystal nickel-based superalloys, most typically using investment casting. During the necessary subsequent solution heat treatment, the formation of recrystallised grains can occur. The introduction of grain boundaries into a single crystal component is potentially detrimental to performance, and therefore manufacturing processes and/or component geometries should be designed to prevent their occurrence. If the boundaries have very low strength, they can degrade the creep and fatigue properties. The root cause for recrystallisation is microscale plasticity caused by differential thermal contraction of metal, mould and core; when the plastic deformation is sufficiently large, recrystallisation takes place. In this work, numerical and thermo-mechanical modelling is carried out, with the aim of establishing computational methods by which recrystallisation during the heat treatment of single crystal nickel-based superalloys can be predicted and prevented prior to their occurrence. Elasto-plastic law is used to predict the plastic strain necessary for recrystallisation. The modelling result shows that recrystallisation is most likely to occur following 1.5–2.5% plastic strain applied at temperatures between 1000 ∘C and 1300 ∘C; this is validated with tensile tests at these elevated temperatures. This emphasises that high temperature deformation is more damaging than low temperature deformation.

  10. Preparation of Inconel 740 superalloy by electron beam smelting

    Energy Technology Data Exchange (ETDEWEB)

    You, Xiaogang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Tan, Yi, E-mail: tanyi@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); You, Qifan; Shi, Shuang; Li, Jiayan [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Ye, Fei [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Wei, Xin [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China)

    2016-08-15

    A novel method, namely electron beam smelting (EBS) technology was used to prepare the Inconel 740 superalloy. The microstructures, hardness and oxidation behavior were characterized and compared with the traditionally prepared Inconel 740 superalloy. The results imply that the solution treatment gives rise to the coarsening of γ′ precipitates, with further aging treatment, the γ′ precipitates with size of less than 30 nm are distributed dispersively in the matrix, leading to a decreasing of the lattice parameters and an increasing of the misfit. The γ′ precipitates result in shearing mechanism of weakly pair coupling. The EBS 740 superalloy produces better properties than that prepared in the traditional method in both precipitation strengthening effect and oxidation resistance. - Highlights: • Electron beam smelting, a new method, was used to prepare the Inconel 740 superalloy. • The EBS 740 shows higher strengthening effect than 740 made in traditional method. • The EBS 740 shows better oxidation resistance than traditional 740. • It shows application prospect of EBS technology in preparing Ni-base superalloys.

  11. Analysis of the cost for the refurbishment of small hydropower plants

    International Nuclear Information System (INIS)

    Ogayar, B.; Vidal, P.G.; Hernandez, J.C.

    2009-01-01

    In view of all the concerns associated with fossil fuels and energy demand it is appropriate to investigate the large number of abandoned small hydropower plants. In order to solve the difficulty implied, by a viability study on the refurbishment of a small hydropower plant, a series of simple equations has been developed based on the economic optimization of the different elements. These equations can also be used for completely new hydropower plants. The result of this study will allow us to obtain quite approximate costs for the refurbishment of old hydropower plants, or the construction of new ones. These data on costs will act as a reference to examine real possibilities of refurbishment through different tools of financial and economic analysis. Although the equations developed have used unitary prices referring to Spain, they will be applicable to other countries just changing those prices for those of the country, required. (author)

  12. Making the home consume less - putting energy efficiency on the refurbishment agenda

    Energy Technology Data Exchange (ETDEWEB)

    Stiess, Immanuel; Deffner, Jutta (Inst. for Social-Ecological Research ISOE GmbH (Germany)). e-mail: stiess@isoe.de; Zundel, Stefan (Lausitz Univ. of Applied Sciences (Germany))

    2009-07-01

    Private home owners can reduce their energy use significantly and move towards a low carbon lifestyle by retrofitting their homes in an energy efficient standard. Despite high awareness for energy efficiency and rising energy prices, home owners only slowly take this opportunity to cut down their personal energy use and carbon emission significantly. In many cases, maintenance and repair activities only result in incremental improvements of energy efficiency. Thus, the dynamics of refurbishment seems to have a conservative bias. Against this background, we will present results from an empirical survey, focussing on home owners' maintenance and refurbishment decisions. Drawing on approaches from social-psychology, lifestyle analysis and evolutionary economics, we will explore the impact of attitudes, lifestyle orientations, cognitive frameworks and social resources on refurbishment decision especially on energy efficient ones and present a model integrating the most important driving factors.

  13. Noburnium: Systems design of niobium superalloys

    Science.gov (United States)

    Misra, Abhijeet

    2005-11-01

    A systems-based approach, integrating quantum mechanical calculations with efficient experimentation, was employed to design niobium-based superalloys. The microstructural concept of gamma-gamma' nickel-based superalloys was adopted, where, the coherent gamma ' aluminides act both as the strengthening phase and a source of aluminum for Al2O3 passivation. Building on previous research, the selected bcc-type ordered aluminide was L2 1 structured Pd2HfAl phase. Comprehensive phase relations were measured on Nb-Pd-Hf-Al prototype alloys, and key tie-tetrahedra were identified. Aluminide precipitation in a bcc matrix was demonstrated in designed Nb+Pd2HfAl alloys. Thermodynamic databases were developed by integrating first-principles calculations with measured phase relations. Atomic volume models were developed for the bcc matrix and the Pd2HfAl phase and matrix elements which would reduce lattice misfit were identified. An experimental 2-phase alloy demonstrated a misfit of 3%. A modified Wagner's model was used to predict the required transient properties to form external Al2O3. The principal oxidation design goal was to decrease the oxygen permeability ( NSOx DO ) divided by the aluminum diffusivity (DAl) by 5 orders of magnitude. A multicomponent mobility database was developed to predict the diffusivities. Guided by first-principles calculations the effect of alloying elements on the oxygen diffusivity in Nb was measured, and the mobility database was experimentally validated. Based on the mobility database, it was found that increasing Al solubility in the bcc matrix greatly increased Al diffusivity. Alloying elements were identified that would increase Al solubility in the bcc matrix. Prototype alloys were prepared and the best oxidation performance was exhibited by a bcc+Nb2Al Nb-Hf-Al alloy, which exhibited parabolic oxidation behavior at 1300°C. The alloy was shown to have achieved the required 5 orders of magnitude reduction in the design parameter. The

  14. Thermo-Viscoplastic Behavior of Ni-Based Superalloy Haynes 282 and Its Application to Machining Simulation

    Directory of Open Access Journals (Sweden)

    Marcos Rodríguez-Millán

    2017-12-01

    Full Text Available Ni-based superalloys are extensively used in high-responsibility applications in components of aerospace engines and gas turbines with high temperature service lives. The wrought, γ’-strengthened superalloy Haynes 282 has been recently developed for applications similar to other common superalloys, such as Waspaloy or Inconel 718, with improved creep behavior, thermal stability, and fabrication ability. Despite the potential of Haynes 282, there are still important gaps in the knowledge of the mechanical behavior of this alloy. In fact, it was not possible to find information concerning the mechanical behavior of the alloy under impulsive loading. This paper focuses on the mechanical characterization of the Haynes 282 at strain rates ranging from 0.1 to 2800 s−1 and high temperatures ranging from 293 to 523 K using Hopkinson bar compression tests. The experimental results from the thermo-mechanical characterization allowed for calibration of the Johnson–Cook model widely used in modeling metallic alloy’s responses under dynamic loading. Moreover, the behavior of Haynes 282 was compared to that reported for Inconel 718, and the results were used to successfully model the orthogonal cutting of Haynes 282, being a typical case of dynamic loading requiring previous characterization of the alloy.

  15. Oxide-assisted crack growth in hold-time low-cycle-fatigue of single-crystal superalloys

    Directory of Open Access Journals (Sweden)

    Suzuki Akane

    2014-01-01

    Full Text Available Compressive hold-time low-cycle fatigue is one of the important damage modes in Ni-based superalloy hot-gas path components. In strain controlled LCF, the compressive hold typically degrades fatigue life significantly due to creep relaxation and the resultant generation of tensile stress upon returning to zero strain. Crack initiation typically occurs on the surface, and therefore, the cracks are covered with layers of oxides. Recent finite element modeling based on experimental observations has indicated that the in-plane compressive stress in the alumina layer formed on the surface of the bond coat assists rumpling and, eventually, leads to initiation of cracks. The stress in the oxide layer continues to assist crack extension by pushing the alumina layer along the crack front during the compressive hold. In-situ measurements of the growth strains of alumina were performed using high energy synchrotron X-rays at Argonne National Lab. Specimens of single-crystal superalloys with and without aluminide coatings were statically pre-oxidized to form a layer of alumina at 1093 and 982 ∘C. For the in-situ synchrotron measurements, the specimens were heated up to the pre-oxidation temperatures with a heater. The alumina layers on both bare and coated specimens show compressive in-plane strains at both temperatures. The oxide strains on the superalloys showed dependency on temperature; on the other hand, the oxide strains in the aluminide coatings were insensitive to temperature. The magnitude of the compressive strains was larger on the superalloys than the ones on the aluminide coatings.

  16. Refurbishment of Pakistan research reactor (PARR-1) for stainless steel lining of the reactor pool

    International Nuclear Information System (INIS)

    Salahuddin, A.; Israr, M.; Hussain, M.

    2002-01-01

    Pakistan Research Reactor-1 (PARR-1) is a pool-type research reactor. Reactor aging has resulted in the increase of water seepage from the concrete walls of the reactor pool. To stop the seepage, it was decided to augment the existing pool walls with an inner lining of stainless steel. This could be achieved only if the pool walls could be accessed unhindered and without excessive radiation doses. For this purpose a partial decommissioning was done by removing all active core components including standard/control fuel elements, reflector elements, beam tubes, thermal shield, core support structure, grid plate and the pool's ceramic tiles, etc. An overall decommissioning program was devised which included procedures specific to each item. This led to the development of a fuel transport cask for transportation, and an interim fuel storage bay for temporary storage of fuel elements (until final disposal). The safety of workers and the environment was ensured by the use of specially designed remote handling tools, appropriate shielding and pre-planned exposure reduction procedures based on the ALARA principle. During the implementation of this program, liquid and solid wastes generated were legally disposed of. It is felt that the experience gained during the refurbishment of PARR-1 to install the stainless steel liner will prove useful and better planning and execution for the future decommissioning of PARR-1, in particular, and for other research reactors like PARR-2 (27 kW MNSR), in general. Furthermore, due to the worldwide activities on decommissioning, especially those communicated through the IAEA CRP on 'Decommissioning Techniques for Research Reactors', the importance of early planning has been well recognized. This has made possible the implementation of some early steps like better record keeping, rehiring of trained manpower, and creation of interim and final waste storage. (author)

  17. Refurbishment and retrofitting of SF6 gas storage tanks of the pelletron accelerator

    International Nuclear Information System (INIS)

    Reddy, G.R.; Datar, V.M.; Parulekar, Y.M.

    2015-01-01

    The BARC-TIFR Pelletron Accelerator Facility has completed more than twenty six years of successful round-the-clock operation, serving diverse users from institutions within and outside DAE. The main accelerating structure and associated subsystems are housed in the accelerator tank under SF 6 gas medium. During maintenance of the accelerator, the SF 6 gas present in the accelerator tank is transferred in the four storage tanks located on the terrace of the building open to outside environment. These four storage tanks (with ∼ 1/4th of the main tank volume each) are ∼ 4.27 m in diameter and ∼ 10 m in height each and are supported on RCC ring beams which are monolithically connected with the RCC structure below. Over the years, the anchor bolts and the base plates of support structure of storage tanks were found corroded and the foundation RCC ring beam indicated a few corrosion cracks. Health assessment of relevant structures and components were carried out. Considering the limitations of existing anchorage and also giving due considerations for reparability and replaceability, a new anchorage system was designed. The entire refurbishment and retrofitting works pertaining to the four SF 6 gas storage tanks was executed in a time bound manner to comply with the then PASC (Particle Accelerator Safety Committee) recommendations successfully, without disrupting the operations of the round-the-clock running Pelletron Accelerator facility. In addition, the thickness measurements for the storage tanks were performed. The relief valves and rupture disc assemblies across the storage tanks were replaced and reinstalled after introducing appropriate manual valves as suggested by the PASC. A new test set up was fabricated to perform pneumatic testing at the recommended pressure off-line for these relief valves and rupture disc assemblies prior to reinstallation. This paper describes the comprehensive rehabilitation and retrofitting procedures that were carried out at the

  18. Metallurgical optimisation of PM superalloy N19

    Directory of Open Access Journals (Sweden)

    Locq Didier

    2014-01-01

    Full Text Available Microstructures of the new PM superalloy N19 have been investigated for various heat treatments in order to reach the best compromise between static strength and cyclic resistance. One subsolvus and several supersolvus heat treatments were applied to produce fine (7 μm and medium (25 μm grain sizes, respectively. The alloy is shown to be quite sensitive to the cooling conditions after solutioning as the γ′ hardening precipitates, both secondary and tertiary, have a direct influence on mechanical properties. Two cooling conditions after solutioning produce a high crack propagation resistance at 650 °C with dwell time cycles, which is one of the basic requirements. The low cycle fatigue behaviour appears to be correlated to the grain size, which determines the origin of crack initiation (from ceramic inclusions or not. The other mechanical properties (tensile, creep remain above target levels. Despite the medium size grain microstructure in the supersolvus condition, a high level of mechanical strength is observed in N19 at elevated temperature. It is understood that further improvement in properties can be achieved by developing coarse grain microstructures.

  19. Boride particles in a powder metallurgy superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Witt, M C; Charles, J A

    1985-12-01

    Using optical and electron metallography, the composition, morphology, and distribution of M/sub 3/B/sub 2/ borides in as-hipped (hot isostatically pressed) samples of the powder metallurgy superalloy Nimonic AP1 have been determined. Two types of boride are present depending on the HIP temperature. Hipping below the boride solvus results in low-aspect ratio particles, distributed both inter- and intragranularly. Hipping above the boride solvus produces high-aspect ratio particles which are exclusively intergranular. A small difference in both lattice parameter and composition has been measured. Electron energy loss spectroscopy of the particles has confirmed the presence of boron, and laser ion-induced mass analysis has indicated a low carbon level. The higher susceptibility to edge cracking during forging of material hipped above the boride solvus is related to the boride morphology. Studies of the subsequent recrystallization of the forged samples have indicated that necklace formation is neither inhibited nor accelerated by the presence of grain boundary borides. 18 references.

  20. Evaluation of powder metallurgy superalloy disk materials

    Science.gov (United States)

    Evans, D. J.

    1975-01-01

    A program was conducted to develop nickel-base superalloy disk material using prealloyed powder metallurgy techniques. The program included fabrication of test specimens and subscale turbine disks from four different prealloyed powders (NASA-TRW-VIA, AF2-1DA, Mar-M-432 and MERL 80). Based on evaluation of these specimens and disks, two alloys (AF2-1DA and Mar-M-432) were selected for scale-up evaluation. Using fabricating experience gained in the subscale turbine disk effort, test specimens and full scale turbine disks were formed from the selected alloys. These specimens and disks were then subjected to a rigorous test program to evaluate their physical properties and determine their suitability for use in advanced performance turbine engines. A major objective of the program was to develop processes which would yield alloy properties that would be repeatable in producing jet engine disks from the same powder metallurgy alloys. The feasibility of manufacturing full scale gas turbine engine disks by thermomechanical processing of pre-alloyed metal powders was demonstrated. AF2-1DA was shown to possess tensile and creep-rupture properties in excess of those of Astroloy, one of the highest temperature capability disk alloys now in production. It was determined that metallographic evaluation after post-HIP elevated temperature exposure should be used to verify the effectiveness of consolidation of hot isostatically pressed billets.

  1. Mechanical characterization of superalloys for space reactors

    International Nuclear Information System (INIS)

    Duchesne, J.

    1989-01-01

    The purpose of this work is the choice of materials usable between 600 and 900 0 C for nuclear space reactor structures. The main criterion of selection for these materials is their good creep behaviour. Consequently, macroscopic theories of creep and several extrapolation methods were described. Superalloys seem the best materials for the studied range of temperatures. Five of them, base nickel, ones unusual in nuclear industry were selected for their good mechanical properties. Three of them are industrial alloys: the first, HAYNES 230 is a recent one, HASTELLOY S and X are more standard materials. The last two, HASTELLOY XR and PYRAD 38 D are issued from special fabrications. Creep tests metallographic investigations, hardness and tensile tests were performed. A contraction of samples was observed during some creep tests under a low stress, 20MPa at 800 0 C, for HAYNES 230 and HASTELLOY X. This could be due to a structural evolution of these materials connected to a decrease of the cristalline parameter. In addition, correlations were observed between certain characteristics determined from slow tensile tests and short duration creep tests. These correlations present a large interest because, at the present time, creep tests cannot be executed on irradiated materials in our laboratories. Consequently creep behaviour of irradiated materials seem may be deduced. Further studies are needed to explain and confirm the behaviour of the most interesting materials under low stresses: HAYNES 230 and HASTELLOY XR to anticipate their behaviour in working conditions [fr

  2. Surface alloying of nickel based superalloys by laser

    International Nuclear Information System (INIS)

    Rodriguez, G.P.; Garcia, I.; Damborenea, J.J. de

    1998-01-01

    Ni based superalloys present a high oxidation resistance at high temperature as well as good mechanical properties. But new technology developments force to research in this materials to improve their properties at high temperature. In this work, two Ni based superalloys (Nimonic 80A and Inconel 600) were surface alloyed with aluminium using a high power laser. SEM and EDX were used to study the microstructure of the obtained coatings. Alloyed specimens were tested at 1.273 K between 24 and 250 h. Results showed the generation of a protective and continuous coating of alumina on the laser treated specimens surface that can improve oxidation resistance. (Author) 8 refs

  3. RA Reactor operation and maintenance (I-IX), part VII, Task 3.08/04, Refurbishment of the RA reactor

    International Nuclear Information System (INIS)

    Zecevic, V.

    1963-12-01

    This volume covers the following reports concerned with the maintenance and repair work of the RA reactor: repair of the technical water system; maintenance of the transportation equipment; vacuuming and drying during refurbishment; repair and decontamination of the distillation device; and the report on participation of the operational dosimetry division in the RA reactor refurbishment activities

  4. Castability of Traditionally Wrought Ni-Based Superalloys for USC Steam Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Jablonski, P D; Cowen, C J; Hawk, J A; Evens, N; Maziasz, P

    2011-02-27

    The high temperature components within conventional coal fired power plants are manufactured from ferritic/martensitic steels. In order to reduce greenhouse gas emissions the efficiency of pulverized coal steam power plants must be increased. The proposed steam temperature in the Advanced Ultra Supercritical (A-USC) power plant is high enough (760°C) that ferritic/martensitic steels will not work due to temperature limitations of this class of materials; thus Ni-based superalloys are being considered. The full size castings are quite substantial: ~4in thick, several feet in diameter and weigh 5-10,000lb each half. Experimental castings were quite a bit smaller, but section size was retained and cooling rate controlled in order to produce relevant microstructures. A multi-step homogenization heat treatment was developed in order to better deploy the alloy constituents. The castability of two traditionally wrought Ni-based superalloys to which minor alloy adjustments have been made in order to improve foundry performance is further explored.

  5. Additive Manufacturing of Nickel Superalloys: Opportunities for Innovation and Challenges Related to Qualification

    Science.gov (United States)

    Babu, S. S.; Raghavan, N.; Raplee, J.; Foster, S. J.; Frederick, C.; Haines, M.; Dinwiddie, R.; Kirka, M. K.; Plotkowski, A.; Lee, Y.; Dehoff, R. R.

    2018-06-01

    Innovative designs for turbines can be achieved by advances in nickel-based superalloys and manufacturing methods, including the adoption of additive manufacturing. In this regard, selective electron beam melting (SEBM) and selective laser melting (SLM) of nickel-based superalloys do provide distinct advantages. Furthermore, the direct energy deposition (DED) processes can be used for repair and reclamation of nickel alloy components. The current paper explores opportunities for innovation and qualification challenges with respect to deployment of AM as a disruptive manufacturing technology. In the first part of the paper, fundamental correlations of processing parameters to defect tendency and microstructure evolution will be explored using DED process. In the second part of the paper, opportunities for innovation in terms of site-specific control of microstructure during processing will be discussed. In the third part of the paper, challenges in qualification of AM parts for service will be discussed and potential methods to alleviate these issues through in situ process monitoring, and big data analytics are proposed.

  6. Creep Crack Initiation and Growth Behavior for Ni-Base Superalloys

    Science.gov (United States)

    Nagumo, Yoshiko; Yokobori, A. Toshimitsu, Jr.; Sugiura, Ryuji; Ozeki, Go; Matsuzaki, Takashi

    The structural components which are used in high temperature gas turbines have various shapes which may cause the notch effect. Moreover, the site of stress concentration might have the heterogeneous microstructural distribution. Therefore, it is necessary to clarify the creep fracture mechanism for these materials in order to predict the life of creep fracture with high degree of accuracy. In this study, the creep crack growth tests were performed using in-situ observational testing machine with microscope to observe the creep damage formation and creep crack growth behavior. The materials used are polycrystalline Ni-base superalloy IN100 and directionally solidified Ni-base superalloy CM247LC which were developed for jet engine turbine blades and gas turbine blades in electric power plants, respectively. The microstructural observation of the test specimens was also conducted using FE-SEM/EBSD. Additionally, the analyses of two-dimensional elastic-plastic creep finite element using designed methods were conducted to understand the effect of microstructural distribution on creep damage formation. The experimental and analytical results showed that it is important to determine the creep crack initiation and early crack growth to predict the life of creep fracture and it is indicated that the highly accurate prediction of creep fracture life could be realized by measuring notch opening displacement proposed as the RNOD characteristic.

  7. A phenomenological creep model for nickel-base single crystal superalloys at intermediate temperatures

    Science.gov (United States)

    Gao, Siwen; Wollgramm, Philip; Eggeler, Gunther; Ma, Anxin; Schreuer, Jürgen; Hartmaier, Alexander

    2018-07-01

    For the purpose of good reproduction and prediction of creep deformation of nickel-base single crystal superalloys at intermediate temperatures, a phenomenological creep model is developed, which accounts for the typical γ/γ‧ microstructure and the individual thermally activated elementary deformation processes in different phases. The internal stresses from γ/γ‧ lattice mismatch and deformation heterogeneity are introduced through an efficient method. The strain hardening, the Orowan stress, the softening effect due to dislocation climb along γ/γ‧ interfaces and the formation of dislocation ribbons, and the Kear–Wilsdorf-lock effect as key factors in the main flow rules are formulated properly. By taking the cube slip in \\{100\\} slip systems and \\{111\\} twinning mechanisms into account, the creep behavior for [110] and [111] loading directions are well captured. Without specific interaction and evolution of dislocations, the simulations of this model achieve a good agreement with experimental creep results and reproduce temperature, stress and crystallographic orientation dependences. It can also be used as the constitutive relation at material points in finite element calculations with complex boundary conditions in various components of superalloys to predict creep behavior and local stress distributions.

  8. Building performance simulation as a design tool for refurbishment of buildings

    NARCIS (Netherlands)

    Hensen, J.L.M.; Bartak, M.; Drkal, F.; Dunovska, T.; Lain, M.; Matuska, T.; Schwarzer, J.; Sourek, B.; Bednar, T.

    2004-01-01

    This paper attempts to outline the current state-of-the-art regarding the use of building performance simulation as a design tool for refurbishment of buildings. This is illus-trated by means of three recent studies for conversion of historical buildings (an early 20th century factory, and a water

  9. LECA refurbishment project or how to get ready for the next ten years

    Energy Technology Data Exchange (ETDEWEB)

    Boussard, Francois; Bois, Dominique; Blanc, Jean Yves

    2005-01-01

    Around 1995, CEA decided a strategy for its hot laboratories: Closing LAMA - Grenoble and LHA - Saclay, after RM2 - Fontenay-aux-Roses. Refurbishing and gathering irradiated material studies in LECI - Saclay. Refurbishing LECA - Cadarache for irradiated fuel examinations. Reprocessing pilot experiments being located in Atalante - Marcoule. Started up in 1964, LECA has got an exploitation license up to August 2005. In 2001, safety authorities agreed to extend it up to 2015, provided an extensive refurbishment is undertaken which includes civil engineering works to achieve the building earthquake resistance, based on 3D-computations and withstanding maximum historically likely earthquake, improving confinement by decontaminating, adding steel boxes inside cells, changing ventilation system and creating a mobile upper cell on the cell roof, changing power supplies, shielded glasses and most manipulators, improving travelling crane, fire protection, radioactivity monitoring and alarms, installing a new device for characterizing and evacuating wastes, decreasing the fissile mass stored inside the facility (source term). Most of the work should be ended by the end of 2005. Afterwards five cells, which do not withstand earthquake, will be deconstructed within 3 years. By mid 2004, 60 % of tasks are completed and all contracts are awarded. The total final cost is 97 M Euro, 80% of which regarding the only LECA refurbishment. (Author)

  10. Physicochemical characteristics and occupational exposure to coarse, fine and ultrafine particles during building refurbishment activities

    Energy Technology Data Exchange (ETDEWEB)

    Azarmi, Farhad; Kumar, Prashant, E-mail: p.kumar@surrey.ac.uk, E-mail: prashant.kumar@cantab.net; Mulheron, Mike [University of Surrey, Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences (United Kingdom); Colaux, Julien L.; Jeynes, Chris [University of Surrey, Faculty of Engineering and Physical Sciences, Ion Beam Centre (United Kingdom); Adhami, Siavash; Watts, John F. [University of Surrey, The Surface Analysis Laboratory, Faculty of Engineering and Physical Sciences (United Kingdom)

    2015-08-15

    Understanding of the emissions of coarse (PM{sub 10} ≤10 μm), fine (PM{sub 2.5} ≤2.5 μm) and ultrafine particles (UFP <100 nm) from refurbishment activities and their dispersion into the nearby environment is of primary importance for developing efficient risk assessment and management strategies in the construction and demolition industry. This study investigates the release, occupational exposure and physicochemical properties of particulate matter, including UFPs, from over 20 different refurbishment activities occurring at an operational building site. Particles were measured in the 5–10,000-nm-size range using a fast response differential mobility spectrometer and a GRIMM particle spectrometer for 55 h over 8 days. The UFPs were found to account for >90 % of the total particle number concentrations and <10 % of the total mass concentrations released during the recorded activities. The highest UFP concentrations were 4860, 740, 650 and 500 times above the background value during wall-chasing, drilling, cementing and general demolition activities, respectively. Scanning electron microscopy, X-ray photoelectron spectroscopy and ion beam analysis were used to identify physicochemical characteristics of particles and attribute them to probable sources considering the size and the nature of the particles. The results confirm that refurbishment activities produce significant levels (both number and mass) of airborne particles, indicating a need to develop appropriate regulations for the control of occupational exposure of operatives undertaking building refurbishment.

  11. A Guide to Energy Efficient Refurbishment. Maintenance and Renewal in Educational Buildings. Building Bulletin 73.

    Science.gov (United States)

    Department for Education and Employment, London (England). Architects and Building Branch.

    With little or relatively modest investment, schools being refurbished or undergoing maintenance can make disproportionately large gains in energy efficiency that can also result in large financial savings. This document offers guidance on the selection of appropriate measures that can improve a facility's energy efficiency, depending on the type…

  12. Low Cost Heat Treatment Process for Production of Dual Microstructure Superalloy Disks

    Science.gov (United States)

    Gayda, John; Gabb, Tim; Kantzos, Pete; Furrer, David

    2003-01-01

    There are numerous incidents where operating conditions imposed on a component mandate different and distinct mechanical property requirements from location to location within the component. Examples include a crankshaft in an internal combustion engine, gears for an automotive transmission, and disks for a gas turbine engine. Gas turbine disks are often made from nickel-base superalloys, because these disks need to withstand the temperature and stresses involved in the gas turbine cycle. In the bore of the disk where the operating temperature is somewhat lower, the limiting material properties are often tensile and fatigue strength. In the rim of the disk, where the operating temperatures are higher than those of the bore, because of the proximity to the combustion gases, resistance to creep and crack growth are often the limiting properties.

  13. An Overview of Ageing Management and Refurbishment of Research Reactors at Trombay

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, R. C.; Raina, V. K. [Bhabha Atomic Research Centre, Mumbai (India)

    2014-08-15

    Three nuclear research reactors have been in operation at Bhabha Atomic Research Centre, Mumbai, India. India has a rich experience of about 120 research reactor operating years including ageing management. A well structured programme is in force for plant life management, refurbishment and upgrading reactors in operation. Apsara, commissioned in August 1956, was the first research reactor. Apsara is a 1 MW{sub th} swimming pool type of reactor with a movable core loaded with enriched uranium fuel and immersed in demineralized light water pool, which serves as coolant, moderator and reflector besides providing radiation shielding. Apsara was shut down during May 2009 for partial decommissioning and upgrading to a 2 MW reactor with several safety upgrades, e.g. a LEU based reactor core with higher neutron flux, a new reactor building meeting seismic qualification criteria and two independent shutdown devices. Cirus, a 40 MW{sub th} tank type reactor utilizing heavy water as moderator, graphite as reflector, demineralized light water as primary coolant and natural uranium metal as fuel; has been in operation since 1960. After about three decade of operation, the availability factor started declining mainly due to outage of equipment exhibiting signs of ageing. After ageing studies and performance review, refurbishment requirements were identified. A programme for refurbishment was drawn that included safety upgrades like civil repairs to the emergency storage reservoir to meet seismic qualification criteria and a new iodine removal system for better efficiency. The reactor was shut down during 1997 for execution of this refurbishment programme. After completion of refurbishment, the reactor was brought back into operation during 2003. It has completed about seven years of safe operation after refurbishment with a significant increase in availability factor from 70% to about 90%. The reactor was permanently shut down during December 2010. The reactor core was unloaded

  14. Cobalt-free nickel-base superalloys

    International Nuclear Information System (INIS)

    Koizumi, Yutaka; Yamazaki, Michio; Harada, Hiroshi

    1979-01-01

    Cobalt-free nickel-base cast superalloys have been developed. Cobalt is considered to be a beneficial element to strengthen the alloys but should be eliminated in alloys to be used for direct cycle helium turbine driven by helium gas from HTGR (high temp. gas reactor). The elimination of cobalt is required to avoid the formation of radioactive 60 Co from the debris or scales of the alloys. Cobalt-free alloys are also desirable from another viewpoint, i.e. recently the shortage of the element has become a serious problem in industry. Cobalt-free Mar-M200 type alloys modified by the additions of 0.15 - 0.2 wt% B and 1 - 1.5 wt% Hf were found to have a creep rupture strength superior or comparable to that of the original Mar-M200 alloy bearing cobalt. The ductility in tensile test at 800 0 C, as cast or after prolonged heating at 900 0 C (the tensile test was done without removing the surface layer affected by the heating), was also improved by the additions of 0.15 - 0.2% B and 1 - 1.5% Hf. The morphology of grain boundaries became intricated by the additions of 0.15 - 0.2% B and 1 - 1.5% Hf, to such a degree that one can hardly distinguish grain boundaries by microscopes. The change in the grain boundary morphology was considered, as suggested previously by one of the authors (M.Y.), to be the reason for the improvements in the creep rupture strength and tensile ductility. (author)

  15. BIM-Based Timber Structures Refurbishment of the Immovable Heritage Listed Buildings

    Science.gov (United States)

    Henek, Vladan; Venkrbec, Václav

    2017-12-01

    The use of Building information model (BIM) design tools is no longer an exception, but a common issue. When designing new buildings or complex renovations using BIM, the benefits have already been repeatedly published. The essence of BIM is to create a multidimensional geometric model of a planned building electronically on a computer, supplemented with the necessary information in advance of the construction process. Refurbishment is a specific process that combines both - new structures and demolished structures, or structures that need to be dismantled, repaired, and then returned to the original position. Often it can be historically valuable part of the building. BIM-based repairs and refurbishments of the constructions, especially complicated repairs of the structures of roof trusses of immovable heritage listed buildings, have not yet been credibly presented. However, the use of BIM tools may be advantageous in this area, because user can quickly response to the necessary changes that may be needed during refurbishments, but also in connection with the quick assessment and cost estimation of any unexpected additional works. The paper deals with the use of BIM in the field of repairs and refurbishment of the buildings in general. The emphasis on monumentally protected elements was priority. Advantage of the proposal research is demonstrated on case study of the refurbishment of the immovable heritage listed truss roof. According to this study, this construction was realized in the Czech Republic. Case study consists of 3D modelled truss parts and the connected technological workflow base. The project work was carried out in one common model environment.

  16. Nanosize boride particles in heat-treated nickel base superalloys

    International Nuclear Information System (INIS)

    Zhang, H.R.; Ojo, O.A.; Chaturvedi, M.C.

    2008-01-01

    Grain boundary microconstituents in aged nickel-based superalloys were studied by transmission electron microscopy techniques. A nanosized M 5 B 3 boride phase, possibly formed by intergranular solute desegregation-induced precipitation, was positively identified. The presence of these intergranular nanoborides provides reasonable clarification of a previously reported reduction of grain boundary liquation temperature during the weld heat affected zone thermal cycle

  17. Multiscale modelling of single crystal superalloys for gas turbine blades

    NARCIS (Netherlands)

    Tinga, T.

    2009-01-01

    Gas turbines are extensively used for power generation and for the propulsion of aircraft and vessels. Their most severely loaded parts, the turbine rotor blades, are manufactured from single crystal nickel-base superalloys. The superior high temperature behaviour of these materials is attributed to

  18. Double minimum creep of single crystal Ni-base superalloys

    Czech Academy of Sciences Publication Activity Database

    WU, X.; Wollgramm, P.; Somsen, C.; Dlouhý, Antonín; Kostka, A.; Eggeler, G.

    2016-01-01

    Roč. 112, JUN (2016), s. 242-260 ISSN 1359-6454 R&D Projects: GA ČR(CZ) GA14-22834S Institutional support: RVO:68081723 Keywords : Single crystal Ni-base superalloys * Primary creep * Transmission electron microscopy * Dislocations * Stacking faults Subject RIV: JG - Metallurgy Impact factor: 5.301, year: 2016

  19. Precipitation in Powder Metallurgy, Nickel Base Superalloys: Review of Modeling Approach and Formulation of Engineering (Postprint)

    Science.gov (United States)

    2016-12-01

    AFRL-RX-WP-JA-2016-0333 PRECIPITATION IN POWDER- METALLURGY , NICKEL-BASE SUPERALLOYS: REVIEW OF MODELING APPROACH AND FORMULATION OF...PRECIPITATION IN POWDER- METALLURGY , NICKEL- BASE SUPERALLOYS: REVIEW OF MODELING APPROACH AND FORMULATION OF ENGINEERING (POSTPRINT) 5a...and kinetic parameters required for the modeling of γ′ precipitation in powder- metallurgy (PM), nickel-base superalloys are summarized. These

  20. A Comparison of the Plastic Flow Response of a Powder Metallurgy Nickel Base Superalloy (Postprint)

    Science.gov (United States)

    2017-04-01

    AFRL-RX-WP-JA-2017-0225 A COMPARISON OF THE PLASTIC-FLOW RESPONSE OF A POWDER- METALLURGY NICKEL-BASE SUPERALLOY (POSTPRINT) S.L...COMPARISON OF THE PLASTIC-FLOW RESPONSE OF A POWDER- METALLURGY NICKEL-BASE SUPERALLOY (POSTPRINT) 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT...behavior at hot-working temperatures and strain rates of the powder- metallurgy superalloy LSHR was determined under nominally-isothermal and transient

  1. Report on participation of the operational dosimetry division in refurbishment of the RA reactor, Task 3.08/04-13

    International Nuclear Information System (INIS)

    Ninkovic, M.

    1963-01-01

    During the refurbishment of the RA reactor, from January to June 1963 the division of operational division had a very important role and comprehensive tasks. To enable safety of the staff it was necessary to provide protection clothes, personnel dosemeters; permanent monitoring of radiation doses; strict control of the procedures for completing the planned maintenance and repair operations to avoid contamination of the personnel and working space. The refurbishment activities described in this report are: removal of fuel from the core; refurbishment of the heavy water system; decontamination of the distillation equipment; repair of the gas system

  2. Recent Advances in Creep Modelling of the Nickel Base Superalloy, Alloy 720Li.

    Science.gov (United States)

    Harrison, William; Whittaker, Mark; Williams, Steve

    2013-03-20

    Recent work in the creep field has indicated that the traditional methodologies involving power law equations are not sufficient to describe wide ranging creep behaviour. More recent approaches such as the Wilshire equations however, have shown promise in a wide range of materials, particularly in extrapolation of short term results to long term predictions. In the aerospace industry however, long term creep behaviour is not critical and more focus is required on the prediction of times to specific creep strains. The current paper illustrates the capability of the Wilshire equations to recreate full creep curves in a modern nickel superalloy. Furthermore, a finite-element model based on this method has been shown to accurately predict stress relaxation behaviour allowing more accurate component lifing.

  3. Analytical cell decontamination and shielding window refurbishment. Final report, March 1984-March 1985

    International Nuclear Information System (INIS)

    Smokowski, R.T.

    1985-01-01

    This is a report on the decontamination and refurbishment of five inactive contaminated analytical cells and six zinc bromide filled shielding windows. The analytical cells became contaminated during the nuclear fuel reprocessing carried out by Nuclear Fuel Services from 1966 to 1972. The decontamination and decommissioning (D and D) work was performed in these cells to make them useful as laboratories in support of the West Valley Demonstration Project. To accomplish this objective, unnecessary equipment was removed from these cells. Necessary equipment and the interior of each cell were decontaminated and repaired. The shielding windows, essentially tanks holding zinc bromide, were drained and disassembled. The deteriorated, opaque zinc bromide was refined to optical clarity and returned to the tanks. All wastes generated in this operation were characterized and disposed of properly. All the decontamination and refurbishment was accomplished within 13 months. The Analytical Hot Cell has been turned over to Analytical Chemistry for the performance high-level waste (HLW) characterization analysis

  4. Decision-making process to shut down, refurbish/modify, or decommission research reactors

    International Nuclear Information System (INIS)

    Stover, R.L.; Murphie, W.E.

    1992-01-01

    Most US research reactors were built more than 20 years ago and some more than 40 years ago. Many have undergone refurbishments and modifications to update their safety systems and experimental capabilities. But changing safety bases, social concerns, and budget constraints have required research reactor operators to continually make decisions to shut down or refurbish/modify their facilities. These decisions involve potential replacement of reactor equipment that has reached its lifetime limits. Changes in philosophy and operation of the reactors are also factors to be considered. In this paper, each of the four factors involved in the decision-making process are discussed in detail. Then, several examples from DOE research reactors in the United States are discussed. Finally, some general conclusions are given to aid in the decision-making process

  5. Refurbish research and test reactors corresponding to global age of nuclear energy

    International Nuclear Information System (INIS)

    Mishima, Kaichiro; Oyama, Yukio; Okamoto, Koji; Yamana, Hajime; Yamaguchi, Akira

    2011-01-01

    This special article featured arguments for refurbishment of research and test reactors corresponding to global age of nuclear energy, based on the report: 'Investigation of research facilities necessary for future joint usage' issued by the special committee of Atomic Energy Society of Japan (AESJ) in September 2010. It consisted of six papers titled as 'Introduction-establishment of AESJ special committee for investigation', 'State of research and test reactors in Japan', 'State of overseas research and test reactors', 'Needs analysis for research and test reactors', 'Proposal of AESJ special committee' and 'Summary and future issues'. In order to develop human resources and promote research and development needed in global age of nuclear energy, research and test reactors would be refurbished as an Asian regional center of excellence. (T. Tanaka)

  6. Refurbishment and upgrading of Iron Gates I Hydroelectric and Navigation System on the Danube River

    International Nuclear Information System (INIS)

    Scvortov, F.; Vasiliu, A.; Rosca, N.

    1996-01-01

    This work shows the problems of the refurbishing the hydroelectric units of the Iron Gates 1 Hydroelectric and Navigation System, operating since 1970. Their long and intensive utilization leads to the necessity of their refurbishment. One is demonstrated by detailed studies that it is sensible and efficient to perform both rehabilitation of the existent hydroelectric units and their power increasing from 175 MW to 190 MW, and prior to all these, as a first step, to install an additional hydroelectric unit (G7) for each system with a capacity of 190 MW. Complex technical and energetic-economical problems appear in realizing this objective due to the necessity of analysing a great volume of data in view of taking a correct decision. (author). 7 figs

  7. Sustainable refurbishment of exterior walls and building facades. Final report, Part A - Methods and recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Hakkinen, T. (ed.)

    2012-11-01

    This report is the final report of Sustainable refurbishment of building facades and exterior walls (SUSREF). SUSREF project was a collaborative (small/medium size) research project within the 7th Framework Programme of the Commission and it was financed under the theme Environment (including climate change) (Grant agreement no. 226858). The project started in October 1st 2009 and ended in April 30th 2012. The project included 11 partners from five countries. SUSREF developed sustainable concepts and technologies for the refurbishment of building facades and external walls. This report together with SUSREF Final report Part B and SUSREF Final Report Part C introduce the main results of the project. Part A focuses on methodological issues. The descriptions of the concepts and the assessment results of the developed concepts are presented in SUSREF Final report part B (generic concepts) and SUSREF Final report Part C (SME concepts). (orig.)

  8. Bruce A refurbishment - preparatory work completed, major tasks to begin soon

    International Nuclear Information System (INIS)

    Boyd, F.

    2006-01-01

    Over the past year Bruce Power has been planning and organizing for an extensive refurbishment of the Units 1 and 2 of the Bruce A station. Now the company and its several major contractors are ready to proceed with the most challenging aspects of the actual work. The largest tasks are the replacement of the 8 steam generators and of the 480 complete fuel channels in each unit Bruce Power has created a separate website connected to their basic one to provide ongoing information about the progress of the work. The following brief note is intended to provide an outline of this challenging refurbishment program and to invite readers to visit this website to follow its progress. To provide background the writer was accorded an informative and interesting tour of the units by Rob Liddle, of Bruce Power, on September 28, 2006 the day after the ceremony commemorating the Douglas Point station held at the Bruce site. (author)

  9. The Efficacy of Waste Management Plans in Australian Commercial Construction Refurbishment Projects

    Directory of Open Access Journals (Sweden)

    Mary Hardie

    2012-11-01

    Full Text Available Renovation and refurbishment of the existingcommercial building stock is a growing area oftotal construction activity and a significantgenerator of waste sent to landfill in Australia. Awritten waste management plan (WMP is awidespread regulatory requirement forcommercial office redevelopment projects. Thereis little evidence, however, that WMPs actuallyincrease the quantity of waste that is ultimatelydiverted from landfill. Some reports indicate anabsence of any formal verification or monitoringprocess by regulators to assess the efficacy ofthe plans. In order to gauge the extent of theproblem a survey was conducted of twenty fourconsultants and practitioners involved incommercial office building refurbishment projectsto determine the state of current practice withregard to WMPs and to elicit suggestions withregard to ways of making the process moreeffective. Considerable variation in commitmentto recycling policies was encountered indicatinga need to revisit waste minimisation practices ifthe environmental performance of refurbishmentprojects is to be improved.

  10. On Stakeholders and the Decision Making Process Concerning Sustainable Renovation and Refurbishment in Sweden, Denmark and Cyprus

    DEFF Research Database (Denmark)

    Gohardani, Navid; Björk, Folke; Jensen, Per Anker

    2013-01-01

    This article examines the decision making process related to sustainable renovation and refurbishment in buildings. The utilized methodology identifies three distinct phases in order to instigate an engagement in sustainable renovation, by means of questionnaires and semi-structured interviews...

  11. Refurbishment of the transportation equipment, Task 3.08/04-10

    International Nuclear Information System (INIS)

    Nikolic, M.; Bratic, A.

    1963-01-01

    Transportation equipment at the RA reactor includes the bridge crane in the reactor hall, another smaller crane, bridge crane in spent fuel storage space, crane for handling the fuel containers n the room 099 and cart of the transportation channel. Regular testing and maintenance during reactor operation was not considered sufficient, and for that reason the repair and maintenance actions were done during the refurbishment of the reactor while it has been shut-down

  12. Experience feedback on the refurbishment of the LECA hot laboratory at Cadarache

    International Nuclear Information System (INIS)

    Grandjean, Jean-Paul; Autran, Bernard; Blanc, Jean-Yves

    2007-01-01

    Full text: After ten years of renovation work, the LECA hot laboratory refurbishment project has finally been completed which means it is now time to draw a few conclusions. Refurbishment of LECA was needed to enable PIE in this laboratory up to 2015. Improvements were made according to the laboratory safety assessment in March 2001. More than 400,000 working hours were clocked up without any serious accidents. The overall radiological record remained below 0.4 man.Sv for this period despite a high contamination level in the venting system and hot cells. The total fissile mass was decreased by a factor of three, and contamination was also considerably reduced. The project was finalised two years later than expected, mainly due to difficulties with two contracts on civil engineering work to improve seismic resistance and on inserting stainless steel casing into some hot cells. Renovation work on existing structures was underestimated, as was the time required to re-commission the cells. The fact that the total number of external staff working inside the facility at the same time was limited also slowed work down. This delay affected the research programmes mainly over the last two years. On the whole, 85 % of all experimentation activities were nevertheless continued during refurbishment. New steps for refurbishment have already been planned so as to extend the LECA service life once again. A line of lead-shielded cells - not designed to withstand current earthquake standards - will be demolished before the end of 2008, and civil engineering operations have been programmed for 2013-2014 so the facility will be able to withstand a maximum design earthquake. (authors)

  13. Application of the ALARP principle to a major refurbishment project at Sellafield

    International Nuclear Information System (INIS)

    Hendrickson, W.R.; Coates, R.

    1989-01-01

    A formalised structured approach to the ALARP principle has been developed and is being applied to occupational radiation exposure on a major refurbishment project at Sellafield. The processes consider the conceptual and subsequent detailed design stages, planning and operational control and incorporates a dose feedback and review system. The approach has led to significant dose savings so far on the project, with recorded doses being significantly less than the doses estimated at the preliminary assessment stage. (author)

  14. Refurbishment of BR2 (Phase 4 and 5)[1997 Scientific Report of the Belgian Nuclear Research Centre

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P.; Dekeyser, J.; Van der Auwera, J.

    1998-07-01

    The extensive refurbishment of the BR-2 materials testing reactor should allow another 10 to 15years of continued operation. The refurbishment programme is required in order to comply with modern safety standards, to enhance the reliability of operation, and to compensate for the ageing of the installations of a facility that has reached about 35 years of intensive service. The main objectives and achievements of phase 4 and 5 are described.

  15. Analysis of laser beam weldability of Inconel 738 superalloy

    International Nuclear Information System (INIS)

    Egbewande, A.T.; Buckson, R.A.; Ojo, O.A.

    2010-01-01

    The susceptibility of pre-weld heat treated laser beam welded IN 738 superalloy to heat affected zone (HAZ) cracking was studied. A pre-weld heat treatment that produced the minimal grain boundary liquation resulted in a higher level of cracking compared to those with more intergranular liquation. This deviation from the general expectation of influence of intergranular liquation extent on HAZ microfissuring is attributable to the reduction in the ability of the base alloy to accommodate welding tensile stress that accompanied a pre-weld heat treatment condition designed to minimize intergranular liquation. Furthermore, in contrast to what has been generally reported in other nickel-based superalloys, a decrease in laser welding speed resulted in increased HAZ cracking in the IN 738, which can be attributed to exacerbated process instability at lower welding speeds.

  16. Phase Stability of a Powder Metallurgy Disk Superalloy

    Science.gov (United States)

    Gabb, Timothy P.; Gayda, John; Kantzos, P.; Telesman, Jack; Gang, Anita

    2006-01-01

    Advanced powder metallurgy superalloy disks in aerospace turbine engines now entering service can be exposed to temperatures approaching 700 C, higher than those previously encountered. They also have higher levels of refractory elements, which can increase mechanical properties at these temperatures but can also encourage phase instabilities during service. Microstructural changes including precipitation of topological close pack phase precipitation and coarsening of existing gamma' precipitates can be slow at these temperatures, yet potentially significant for anticipated disk service times exceeding 1,000 h. The ability to quantify and predict such potential phase instabilities and degradation of capabilities is needed to insure structural integrity and air worthiness of propulsion systems over the full life cycle. A prototypical advanced disk superalloy was subjected to high temperature exposures, and then evaluated. Microstructural changes and corresponding changes in mechanical properties were quantified. The results will be compared to predictions of microstructure modeling software.

  17. Microstructure evolution during dynamic recrystallization of hot deformed superalloy 718

    International Nuclear Information System (INIS)

    Wang, Y.; Shao, W.Z.; Zhen, L.; Zhang, X.M.

    2008-01-01

    Microstructure evolution during dynamic recrystallization (DRX) of superalloy 718 was studied by optical microscope and electron backscatter diffraction (EBSD) technique. Compression tests were performed at different strains at temperatures from 950 deg. C to 1120 deg. C with a strain rate of 10 -1 s -1 . Microstructure observations show that the recrystallized grain size as well as the fraction of new grains increases with the increasing temperature. A power exponent relationship is obtained between the dynamically recrystallized grain size and the peak stress. It is found that different nucleation mechanisms for DRX are operated in hot deformed superalloy 718, which is closely related to deformation temperatures. DRX nucleation and development are discussed in consideration of subgrain rotation or twinning taking place near the original grain boundaries. Particular attention is also paid to the role of continuous dynamic recrystallization (CDRX) at both higher and lower temperatures

  18. Surface modification, microstructure and mechanical properties of investment cast superalloy

    OpenAIRE

    M. Zielińska; K. Kubiak; J. Sieniawski

    2009-01-01

    Purpose: The aim of this work is to determine physical and chemical properties of cobalt aluminate (CoAl2O4) modifiers produced by different companies and the influence of different types of modifiers on the grain size, the microstructure and mechanical properties of high temperature creep resisting superalloy René 77.Design/methodology/approach: The first stage of the research work took over the investigations of physical and chemical properties of cobalt aluminate manufactured by three diff...

  19. Powder-metallurgy superalloy strengthened by a secondary gamma phase.

    Science.gov (United States)

    Kotval, P. S.

    1971-01-01

    Description of experiments in which prealloyed powders of superalloy compositions were consolidated by extrusion after the strengthening by precipitation of a body-centered tetragonal gamma secondary Ni3 Ta phase. Thin foil electron microscopy showed that the mechanical properties of the resultant powder-metallurgy product were correlated with its microstructure. The product exhibited high strength at 1200 F without loss of ductility, after thermomechanical treatment and aging.

  20. Deformation-phase transformation coupling mechanism of white layer formation in high speed machining of FGH95 Ni-based superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jin [School of Mechanical and Automotive Engineering, Qilu University of Technology, Jinan, Shandong 250353 (China); Liu, Zhanqiang, E-mail: melius@sdu.edu.cn [School of Mechanical Engineering, Shandong University, Jinan, Shandong 250061 (China); Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Shandong University, Ministry of Education, Shandong (China); Lv, Shaoyu [School of Mechanical Engineering, Shandong University, Jinan, Shandong 250061 (China)

    2014-02-15

    Ni-based superalloy represents a significant metal portion of the aircraft critical structural and engine components. When these critical structural components in aerospace industry are manufactured with the objective to reach high reliability levels and excellent service performance, surface integrity is one of the most relevant parameter used for evaluating the quality of finish machined surfaces. In the study of surface integrity, the formation white layer is a very important research topic. The formation of white layer on the Ni-based superalloy machined surface will reduce the machined parts service performance and fatigue life. This paper was conducted to determine the effects of cutting speed on white layer formation in high speed machining of FGH95 Ni-based superalloy. Optical microscope, scanning electron microscope and X-ray diffraction were employed to analyze the elements and microstructures of white layer and bulk materials. The statistical analysis for grain numbers was executed to study the influence of cutting speed on the grain refinement in the machined surface. The investigation results showed that white layer exhibits significantly different microstructures with the bulk materials. It shows densification, no obvious structural features characteristic. The microstructure and phase of Ni-based solid solution changed during cutting process. The increase of cutting speed causes the increase of white layer thickness when the cutting speed is less than 2000 m/min. However, white layer thickness reduces with the cutting speed further increase. The higher the cutting speed, the more serious grains refinement in machined surface. 2-D FEM for machining FGH95 were carried out to simulate the cutting process and obtained the cutting temperature field, cutting strain field and strain rate field. The impact mechanisms of cutting temperature, cutting strain and strain rates on white layer formation were analyzed. At last, deformation-phase transformation

  1. Rafting in single crystal nickel-base superalloys – An overview

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Page 1 ... aircraft engines as well as land-based power generation applications. Microstruc- ture and high temperature mechanical properties are the major factors controlling the performance of SX ... Single crystal (SX) superalloys are a group of nickel-base superalloys. They exhibit superior high temperatur mechanical ...

  2. Erosion–corrosion behaviour of Ni-based superalloy Superni-75 in ...

    Indian Academy of Sciences (India)

    microscopy/energy-dispersive analysis (SEM/EDAX) and electron probe micro ... gas turbines and they have designated this alloy as superalloy Superni-75. ... The nickel-based superalloy Superni-75 (19·5Cr-3Fe-0·3Ti-0·1C- Balance Ni) was ...

  3. The oxidation of aluminide diffusion coatings containing platinum used for the protection of IN738 superalloy

    International Nuclear Information System (INIS)

    Hanna, M.D.; Haworth, C.W.

    1993-01-01

    Aluminide coatings, as used for the protection against oxidation of most nickel-base superalloy components in modern jet engines, have been formed by a diffusion process on IN738 to give a coating that is essentially NiAl containing Al-rich precipitates. Aluminide coatings containing platinum have also been produced by initially depositing a thin layer (several microns thick) of Pt on the superalloy prior to the aluminisation process. Depending upon the details of the processing (such as the thickness of the Pt or the Al flux during the diffusion process) the structure of the coating on being formed was essentially either PtAl/sub 2/, PtAl or NiAl, or a mixture of these phases, but after some hours heat treatment at a high temperature (equivalent to service) was converted to either NiAl (containing Pt), or PtAl (containing Ni) or a mixture of PtAl and NiAl. The oxidation rate of these coatings at different temperatures between 800 and 1000 deg. C was studied using an automatic recording micro-balance and compared with the oxidation rate of a simple aluminide coating and of uncoated IN738. Further longer-term oxidation tests, including cyclic tests, were also undertaken. The Pt containing coatings gave approximately the same performance, and some were slightly better than the simple aluminide coatings, (and much better than the uncoated IN738). Both sections through the oxidised surface of the Al/sub 2/O/sub 3/ scale formed on the coatings were examined using optical microscopy and the SEM. The coating/scale interface on the platinum aluminide was seen to be slightly convoluted. It was more adherent and showed less tendency to spall than that formed on the simple aluminide coating. (author)

  4. Fatigue strain mapping via digital image correlation for Ni-based superalloys: The role of thermal activation on cube slip

    International Nuclear Information System (INIS)

    Mello, Alberto W.; Nicolas, Andrea; Sangid, Michael D.

    2017-01-01

    A deformation mechanism map for a Ni-based superalloy is presented during cyclic loading at low (300 °C), intermediate (550 °C), and high (700 °C) temperatures for low (0.7%) and high (1.0%) applied strain amplitudes. Strain mapping is performed via digital image correlation (DIC) during interrupted fatigue experiments at elevated temperatures at 1, 10, 100 and 1000 cycles, for each specified loading and temperature condition. The DIC measurements are performed in a scanning electron microscope, which allows high-resolution measurements of heterogeneous slip events and a vacuum environment to ensure stability of the speckle pattern for DIC at high temperatures. The cumulative fatigue experiments show that the slip bands are present in the first cycle and intensify with number of cycles; resulting in highly localized strain accumulation. The strain mapping results are combined with microstructure characterization via electron backscatter diffraction. The combination of crystal orientations and high-resolution strain measurements was used to determine the active slip planes. At low temperatures, slip bands follow the {111} octahedral planes. However, as temperature increases, both the {111} octahedral and {100} cubic slip planes accommodate strain. The activation of cubic slip via cross-slip within the ordered intermetallic γ’ phase has been well documented in Ni-based superalloys and is generally accepted as the mechanism responsible for the anomalous yield phenomenon. The results in this paper represent an important quantifiable study of cubic slip system activity at the mesoscale in polycrystalline γ-γ’ Ni-based superalloys, which is a key advancement to calibrate the thermal activation components of polycrystalline deformation models.

  5. Influence of γ' precipitates on Portevin–Le Chatelier effect of Ni-based superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yulong [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei 230027 (China); Tian, Chenggang [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Fu, Shihua, E-mail: fushihua@ustc.edu.cn [CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei 230027 (China); Han, Guoming [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Cui, Chuanyong, E-mail: chycui@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, Qingchuan, E-mail: zhangqc@ustc.edu.cn [CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei 230027 (China)

    2015-06-25

    The γ′ precipitate plays a critical role in improving the mechanical properties of Ni-based superalloys. An undesirable phenomenon referred to as the Portevin–Le Chatelier (PLC) effect always appears in Ni-based superalloys deformed within specific ranges of strain rate and temperature. In order to systematically investigate the influence of the γ′ precipitates on the PLC effect, four Ni-based superalloys with various γ′ contents were designed and fabricated. Microscopic observations from transmission electron microscopy (TEM) indicated that the volume fraction of the γ′ phase was consistent with the designed value. Furthermore, analysis of energy dispersive spectroscopy (EDS) results revealed that the γ matrix of all the alloys consisted of the same components. Uniaxial tensile tests were performed at strain rates and temperatures ranging from 1×10{sup −4} to 3×10{sup −3} s{sup −1} and 300–500 °C, respectively. We found that the ultimate strength increased while the elongation decreased with increasing γ′ content. In addition, the serration changed from type A to type B and to type C with increasing temperature, decreasing strain rate or increasing γ′ content; the amplitude of type B serrations was described by unimodal or bimodal distributions. Increasing volume fraction of γ′ precipitates shifted the region in which the PLC effect occurred, to the range of low temperatures and high strain rates. Moreover, the serration amplitude increased with increasing γ′ content at a given temperature, which indicated that the γ′ precipitate increases the dynamic strain ageing (DSA) effect.

  6. Fatigue strain mapping via digital image correlation for Ni-based superalloys: The role of thermal activation on cube slip

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Alberto W.; Nicolas, Andrea; Sangid, Michael D., E-mail: msangid@purdue.edu

    2017-05-17

    A deformation mechanism map for a Ni-based superalloy is presented during cyclic loading at low (300 °C), intermediate (550 °C), and high (700 °C) temperatures for low (0.7%) and high (1.0%) applied strain amplitudes. Strain mapping is performed via digital image correlation (DIC) during interrupted fatigue experiments at elevated temperatures at 1, 10, 100 and 1000 cycles, for each specified loading and temperature condition. The DIC measurements are performed in a scanning electron microscope, which allows high-resolution measurements of heterogeneous slip events and a vacuum environment to ensure stability of the speckle pattern for DIC at high temperatures. The cumulative fatigue experiments show that the slip bands are present in the first cycle and intensify with number of cycles; resulting in highly localized strain accumulation. The strain mapping results are combined with microstructure characterization via electron backscatter diffraction. The combination of crystal orientations and high-resolution strain measurements was used to determine the active slip planes. At low temperatures, slip bands follow the {111} octahedral planes. However, as temperature increases, both the {111} octahedral and {100} cubic slip planes accommodate strain. The activation of cubic slip via cross-slip within the ordered intermetallic γ’ phase has been well documented in Ni-based superalloys and is generally accepted as the mechanism responsible for the anomalous yield phenomenon. The results in this paper represent an important quantifiable study of cubic slip system activity at the mesoscale in polycrystalline γ-γ’ Ni-based superalloys, which is a key advancement to calibrate the thermal activation components of polycrystalline deformation models.

  7. The Mechanical Properties of Candidate Superalloys for a Hybrid Turbine Disk

    Science.gov (United States)

    Gabb, Timothy P.; MacKay, Rebecca A.; Draper, Susan L.; Sudbrack, Chantal K.; Nathal, Michael V.

    2013-01-01

    The mechanical properties of several cast blade superalloys and one powder metallurgy disk superalloy were assessed for potential use in a dual alloy hybrid disk concept of joined dissimilar bore and web materials. Grain size was varied for each superalloy class. Tensile, creep, fatigue, and notch fatigue tests were performed at 704 to 815 degC. Typical microstructures and failure modes were determined. Preferred materials were then selected for future study as the bore and rim alloys in this hybrid disk concept. Powder metallurgy superalloy LSHR at 15 micron grain size and single crystal superalloy LDS-1101+Hf were selected for further study, and future work is recommended to develop the hybrid disk concept.

  8. High temperature oxidation and corrosion behavior of Ni-base superalloy in He environment

    International Nuclear Information System (INIS)

    Lee, Gyoeng Geun; Park, Ji Yeon; Jung, Su jin

    2010-11-01

    Ni-base superalloy is considered as a IHX (Intermediate Heat Exchanger) material for VHTR (Very High Temperature Gas-Cooled Reactor). The helium environment in VHTR contains small amounts of impure gases, which cause oxidation, carburization, and decarburization. In this report, we conducted the literature survey about the high temperature behavior of Ni-base superalloys in air and He environments. The basic information of Ni-base superalloy and the basic metal-oxidation theory were briefly stated. The He effect on the corrosion of Ni-base superalloy was also summarized. This works would provide a brief suggestion for the next research topic for the application of Ni-base superalloy to VHTR

  9. High-Rise Refurbishment: The Energy-Efficient Upgrade of Multi-Story Residences in the European Union

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Some 36 million European households are in high-rise residences, one in six of all households, and yet many of the buildings are in urgent need of refurbishment. This study, which is one in a series being conducted on behalf of the International Energy Agency addressing the energy performance of the existing IEA-wide building stock, identifies a Europe-wide cost-effective energy saving potential of 28% from energy-efficient refurbishment of the high-rise residential building stock. Attainment of this potential would imply a 1.5% reduction of Europe's total final energy demand and annual CO2 emissions savings of 35 Mt. In practice only the less efficient buildings need to be refurbished to realise these stockaverage savings and for these buildings typical savings in heating energy from refurbishment of between 70 and 80% are identified. Buildings in general suffer from a variety of barriers that tend to prevent their occupants from maintaining and refurbishing them to levels of comfort and energy performance that would be justified over the longer term, but collective housing in general is particularly susceptible to market failures. Many occupants do not own the property while their landlords usually have little motivation to finance improvements. Refurbishment requires collective agreement on a capital investment, which is difficult to establish especially when some occupants expect to live in the building over the longer-term but others only for the short-term. Furthermore, in most cases the occupants of high-rise residences are not among the wealthier members of society and they find it difficult to raise capital for longer-term investments. It is not surprising, then, to find that this section of the building stock is the most neglected and that there remain significant cost-effective opportunities for it to be refurbished in a way that improves comfort, saves energy, reduces CO2 emissions and significantly improves the urban environment.

  10. Densifying the city: urban recycle as a strategic system to refurbish the built environment

    Directory of Open Access Journals (Sweden)

    Vittorino Belpoliti

    2015-11-01

    Full Text Available The persisting economic crisis and the necessity for more sustainable construction processes imply the need for innovative strategies to reuse the existing building stock. Retrofit and recycling plans are already active for whole city districts, adopting the urban densification strategy to reduce the consumption of resources, promoting the functional, technological, and energy refurbishment of the existing city districts The study introduces considerations and tools to increase the efficiency of retrofit action onto abandoned and degraded area through the improvement of their energy and environmental performances. 

  11. Motier church - refurbishment of heating system; Kirche Motier Sanierung der Raumheizung

    Energy Technology Data Exchange (ETDEWEB)

    Grizzetti, V.

    2003-07-01

    This final report for the Swiss Federal Office for Energy describes the refurbishment of the space heating system of the historical church in Motier, Switzerland. The 50-year old, inefficient electrical direct heating system of the church, which is a listed building, and the new, heat pump-based system are described. Heating energy is distributed via a warm-air system, geothermal energy provides the primary heat source for the heat pump. Technical details of the heating characteristics and energy consumption of the old and new heating systems are presented in the form of tables and diagrams. The maintenance of the heating system's ventilation unit is also discussed.

  12. Refurbishment of damaged tools using the combination of GTAW and laser beam welding

    Directory of Open Access Journals (Sweden)

    J. Tušek

    2014-10-01

    Full Text Available This paper presents the use of two welding processes for the refurbishment of damaged industrial tools. In the first part the problem is presented followed by the comparison of GTAW and laser welding in terms of repair welding of damaged tools. The macrosections of the welds show the difference between both welding processes in repairing of damaged tools. At the conclusion the main findings are presented. In many cases it is useful to use both welding processes in order to achieve better weld quality and to make welding more economical. The order of the technology used depends on the tool material, the use of the tool and the tool damage.

  13. Applying a CPLD for Refurbishment of a Multi-channel Pulse Height Analyzer

    International Nuclear Information System (INIS)

    Leetragunpichitchai, Supalerk; Thong-Aram, Decho; Ploykrachang, Kamontip

    2007-08-01

    Full text: This research applied a CPLD for construction of a 100 MHz, 2048 channel, Wilkinson type analog to digital converter (ADC) circuits for refurbishment of an original multi-channel pulse height analyzer (PHA) ADC. Introduction of the CPLD could reduce the complexity of the circuits, equipment size and also the power consumption while the operation speed was increased. The linearity test of the ADC was found to be excellent with an R2 = 0.9995 and a maximum pulse rate of 48.828 k cps could be converted in this system. Therefore the developed system was appropriate for replacing the original ADC

  14. Refurbishment of small hydropower plants in Romania; Sanierung von Kleinwasserkraftwerken in Rumaenien

    Energy Technology Data Exchange (ETDEWEB)

    Gmeinbauer, Joerg [Wien Energie GmbH, Wien (Austria)

    2010-07-01

    In 2008 Wien Energie subsidiary Wienstrom GmbH participated in three public auctions of Hidroelectrica S.A. for the sale of old small hydro power plants in Romania. Together with strategic partners Wienstrom could successfully compete against local and international competition and acquired 31 small hydro power plants with a total installed capacity of around 20 MW. The plants were integrated into the newly established Vienna Energy Forta Naturala Srl. and are being completely refurbished at the moment. Wien Energie consequently is already the third largest operator of small hydro power plants in Romania. (orig.)

  15. Production and Characterization of WC-Reinforced Co-Based Superalloy Matrix Composites

    Science.gov (United States)

    Özgün, Özgür; Dinler, İlyas

    2018-05-01

    Cobalt-based superalloy matrix composite materials were produced through the powder metallurgy technique using element powders at high purity and nano-sized wolfram carbide (WC) reinforcement in this study. An alloy that had the same chemical composition as the Stellite 6 alloy but not containing carbon was selected as the matrix alloy. The powder mixtures obtained as a result of mixing WC reinforcing member and element powders at the determined ratio were shaped by applying 300 MPa of pressure. The green components were sintered under argon atmosphere at 1240 °C for 120 minutes. The densities of the sintered components were determined by the Archimedes' principle. Microstructural characterization was performed via X-ray diffraction analysis, scanning electron microscope examinations, and energy-dispersive spectrometry. Hardness measurements and tensile tests were performed for determining mechanical characteristics. The relative density values of the sintered components increased by increasing the WC reinforcement ratio and they could almost reach the theoretical density. It was determined from the microstructural examinations that the composite materials consisted of fine and equiaxed grains and coarse carbides demonstrating a homogeneous dispersion along the microstructure at the grain boundaries. As it was the case in the density values, the hardness and strength values of the composites increased by increasing the WC ratio.

  16. Microstructural Changes during High Temperature Service of a Cobalt-Based Superalloy First Stage Nozzle

    Directory of Open Access Journals (Sweden)

    A. Luna Ramírez

    2016-01-01

    Full Text Available Superalloys are a group of alloys based on nickel, iron, or cobalt, which are used to operate at high temperatures (T > 540°C and in situations involving very high stresses like in gas turbines, particularly in the manufacture of blades, nozzles, combustors, and discs. Besides keeping its high resistance to temperatures which may approach 85% of their melting temperature, these materials have excellent corrosion resistance and oxidation. However, after long service, these components undergo mechanical and microstructural degradation; the latter is considered a major cause for replacement of the main components of gas turbines. After certain operating time, these components are very expensive to replace, so the microstructural analysis is an important tool to determine the mode of microstructure degradation, residual lifetime estimation, and operating temperature and most important to determine the method of rehabilitation for extending its life. Microstructural analysis can avoid catastrophic failures and optimize the operating mode of the turbine. A case study is presented in this paper.

  17. Hot deformation behavior of delta-processed superalloy 718

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y., E-mail: wangyanhit@yahoo.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); School of Aeronautics and Astronautics, Central South University, Changsha 410083 (China); Shao, W.Z.; Zhen, L.; Zhang, B.Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-03-25

    Research highlights: {yields} The peak stress for hot deformation can be described by the Z parameter. {yields} The grain size of DRX was inversely proportional to the Z parameter. {yields} The dissolution of {delta} phases was greatly accelerated under hot deformation. {yields}The {delta} phase stimulated nucleation can serve as the main DRX mechanism. - Abstract: Flow stress behavior and microstructures during hot compression of delta-processed superalloy 718 at temperatures from 950 to 1100 deg. C with strain rates of 10{sup -3} to 1 s{sup -1} were investigated by optical microscopy (OM), electron backscatter diffraction (EBSD) technique and transmission electron microscopy (TEM). The relationship between the peak stress and the deformation conditions can be expressed by a hyperbolic-sine type equation. The activation energy for the delta-processed superalloy 718 is determined to be 467 kJ/mol. The change of the dominant deformation mechanisms leads to the decrease of stress exponent and the increase of activation energy with increasing temperature. The dynamically recrystallized grain size is inversely proportional to the Zener-Hollomon (Z) parameter. It is found that the dissolution rate of {delta} phases under hot deformation conditions is much faster than that under static conditions. Dislocation, vacancy and curvature play important roles in the dissolution of {delta} phases. The main nucleation mechanisms of dynamic recrystallization (DRX) for the delta-processed superalloy 718 include the bulging of original grain boundaries and the {delta} phase stimulated DRX nucleation, which is closely related to the dissolution behavior of {delta} phases under certain deformation conditions.

  18. Study of the oxidation kinetics of the MA 956 superalloy

    International Nuclear Information System (INIS)

    Garcia-Alonso, M.C.; Gonzalez-Carrasco, J.L.; Escudero, M.L.

    1998-01-01

    This work deals with the oxidation kinetics of the MA 956 superalloy in the temperature range of 800-1,200 degree centigree for up to 200 h exposure. During oxidation the alloy develops a fine, compact and very well adhered α-alumina layer, the thickness of which increases with increasing time and temperature. The oxidation kinetics obeys a sub parabolic type behaviour. The scale growth seems to occur by two different oxidation mechanisms; above 1,050 degree centigree, the oxidation process would be controlled by α-alumina, and below 900 degree centigree by γ-alumina. (Author) 17 refs

  19. Oxidation behavior and compositional analysis of aluminized superalloy

    International Nuclear Information System (INIS)

    Khalid, F.A.; Nawaz, F.

    2003-01-01

    The high temperature oxidation behavior of superalloy specimens used for the manufacture of turbine blades has been examined using scanning electron microscopy (SEM) and fine-probe spot and line scan EDS microanalysis techniques. The performance of aluminized coating applied to the specimens has also been examined. It was observed that complex oxides are formed in both coated and uncoated specimens. However the coated specimens revealed a greater stability of gamma phase and integrity of aluminized coating as compared with uncoated specimens. The microchemical and microstructural changes that occurred during oxidation have been analyzed to examine characteristics of oxide layers. (author)

  20. Microstructural causes of negative creep in cast superalloys

    International Nuclear Information System (INIS)

    Frank, G.

    1990-01-01

    The dissertation examines by means of microstructural investigations and modelling calculations two types of superalloys: the nickel-base cast alloy IN 738 LC (γ'-hardened, containing MC and M 23 C 6 carbides), and the cobalt-base cast alloy FSX 414 (containing M 23 C 6 carbides, solid solution-hardened). The task was to determine the causes of microstructural volume contraction, in order to improve and facilitate explanation and extrapolation of the materials' long-term behaviour at high temperatures, and to derive if possible information on appropriate measures preventing negative creep, which may lead to critical damage of bolted joints, for instance. (orig./MM) [de

  1. The effectiveness of environment assessment tools to guide refurbishment of Australian residential aged care facilities: A systematic review.

    Science.gov (United States)

    Neylon, Samantha; Bulsara, Caroline; Hill, Anne-Marie

    2017-06-01

    To determine applicability of environment assessment tools in guiding minor refurbishments of Australian residential aged care facilities. Studies conducted in residential aged care settings using assessment tools which address the physical environment were eligible for inclusion in a systematic review. Given these studies are limited, tools which have not yet been utilised in research settings were also included. Tools were analysed using a critical appraisal screen. Forty-three publications met the inclusion criteria. Ten environment assessment tools were identified, of which four addressed all seven minor refurbishment domains of lighting, colour and contrast, sound, flooring, furniture, signage and way finding. Only one had undergone reliability and validity testing. There are four tools which may be suitable to use for minor refurbishment of Australian residential aged care facilities. Data on their reliability, validity and quality are limited. © 2017 AJA Inc.

  2. Refurbishment of the rotating rack of the OSU TRIGA MKII reactor

    International Nuclear Information System (INIS)

    Higginbotham, J.F.; Dodd, B.; Pratt, D.S.; Anderson, T.V.

    1992-01-01

    Many TRIGA reactors have experienced operational difficulties with the rotating racks used for sample irradiation. Generally the rack gradually becomes more difficult to rotate until it finally seizes. The recommended action at that point is replacement of the entire facility at a significant cost. The purpose of this paper is to describe the symptoms leading to rack failure and to present the results of a refurbishment procedure that does not involve the use of solvents which create mixed chemical and radioactive hazardous waste. The primary reason for rack failure is the buildup of sludge produced through irradiation of lubrication oil. The refurbishment procedure involves using a commercially available degreasing solution which can be pumped into and out of the rack with the objective of removing this sludge. The solution used is sold under the trade name 'Simple Green'. No radioactive material was detected on smear or air samples taken of the work area during the reifurbishment activities and the rack rotates freely in both direction even after eighteen months of operation. The only disadvantage to performing this procedure has been the need to maintain a very aggressive contamination control program when unloading samples from the rack. A very fine particulate material attaches to the outside of tubes used to encapsulate samples. This material can produce contamination levels of 10,000 dpm/100 cm 2 in the worst cases but will typically produce local hot spots on the order of 1000 dpm. (author)

  3. The Prevelence of SBS and Absenteeism among Children in Urban Refurbished Private Preshools

    Directory of Open Access Journals (Sweden)

    Salleh Naziah Muhamad

    2016-01-01

    Full Text Available The preschool education is compulsory to children in Malaysia. This regulation has encouraged more premises to be refurbished as a pre-school building. This paper examines the pupils’ absenteeism and the prevalence of Sick Building Symptoms (SBS initiated in congested private preschool with different ventilation strategies. The study analysed data from the attendance record of 10 classrooms and the questionnaire surveys administered to 151 parents about their children health symptoms once they were leaving the schools building. Questions on SBS used 5-point likert scale with symptoms concern on nose, eye, head, throat, skin, breath and tiredness. The descriptive and chi-square test applied to obtain the association of SBS and ventilation strategies in the classrooms. With quantitative and qualitative explanation, the unhealthy environment in refurbished pre-schools explained. Running nose, coughing and sore throat frequently reported in air-conditioning (AC classrooms. The higher absent rate found in AC classrooms. These symptoms show there were weaknesses in ventilation performance and environment in the selected preschools. Further analyses on objective measurements in future research are strongly recommended.

  4. Exposure management in a hot-cell decontamination and refurbishment campaign

    International Nuclear Information System (INIS)

    Courtney, J.C.; Ferguson, K.R.; Chesnovar, D.L.; Huebner, M.F.

    1984-01-01

    We developed a minicomputer-based system to provide rapid access to personnel dosimetry data during a campaign to decontaminate and refurbish a hot-cell at the Hot Fuel Examination Facility (HFEF) Complex. This system allows project management to estimate doses for future tasks, assess the effectiveness of decontamination and personnel protection techniques, and balance exposures among members of various skill groups. As the campaign progresses, projected total exposures can be minimized by tradeoffs between estimated doses during decontamination and estimated dose savings during the refurbishment phase. The effectiveness of various dose-reduction procedures can be compared on the basis of data from a few cell entries before more extensive routine operations are scheduled. Because the radiation fields vary significantly with location in the cell, we find that measurements of whole-body, skin, and extremity doses are more valuable than dose-rate information. Penetrating and skin radiation doses to personnel can be compared to administrative guidelines. This helps us to select the most effective combination of protective clothing. For example, leaded gauntlets reduce the dose rate to the workers' hands, but their use can increase the time required for some in-cell tasks. Hence, use of gauntlets can lead to higher whole-body and skin doses. The program is written for the HFEF Complex Harris/6 minimainframe computer with a disk-monitor operating system

  5. High temperature deformation mechanisms of L12-containing Co-based superalloys

    Science.gov (United States)

    Titus, Michael Shaw

    Ni-based superalloys have been used as the structural material of choice for high temperature applications in gas turbine engines since the 1940s, but their operating temperature is becoming limited by their melting temperature (Tm =1300degrees C). Despite decades of research, no viable alternatives to Ni-based superalloys have been discovered and developed. However, in 2006, a ternary gamma' phase was discovered in the Co-Al-W system that enabled a new class of Co-based superalloys to be developed. These new Co-based superalloys possess a gamma-gamma' microstructure that is nearly identical to Ni-based superalloys, which enables these superalloys to achieve extraordinary high temperature mechanical properties. Furthermore, Co-based alloys possess the added benefit of exhibiting a melting temperature of at least 100degrees C higher than commercial Ni-based superalloys. Superalloys used as the structural materials in high pressure turbine blades must withstand large thermomechanical stresses imparted from the rotating disk and hot, corrosive gases present. These stresses induce time-dependent plastic deformation, which is commonly known as creep, and new superalloys must possess adequate creep resistance over a broad range of temperature in order to be used as the structural materials for high pressure turbine blades. For these reasons, this research focuses on quantifying high temperature creep properties of new gamma'-containing Co-based superalloys and identifying the high temperature creep deformation mechanisms. The high temperature creep properties of new Co- and CoNi-based alloys were found to be comparable to Ni-based superalloys with respect to minimum creep rates and creep-rupture lives at 900degrees C up to the solvus temperature of the gamma' phase. Co-based alloys exhibited a propensity for extended superlattice stacking fault formation in the gamma' precipitates resulting from dislocation shearing events. When Ni was added to the Co-based compositions

  6. Precipitate microstructure evolution in exposed IN738LC superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Strunz, Pavel, E-mail: strunz@ujf.cas.cz [Nuclear Physics Institute ASCR, CZ-25068 Řež near Prague (Czech Republic); Petrenec, Martin [Institute of Physics of Materials of the AS CR, Brno (Czech Republic); Gasser, Urs [Laboratory for Neutron Scattering, PSI, CH-5232 Villigen (Switzerland); Tobiáš, Jiří; Polák, Jaroslav [Institute of Physics of Materials of the AS CR, Brno (Czech Republic); Šaroun, Jan [Nuclear Physics Institute ASCR, CZ-25068 Řež near Prague (Czech Republic)

    2014-03-15

    Highlights: • Evolution of γ′-phase morphology in IN738LC Ni-base superalloy was examined by SANS. • In situ tests at high temperatures revealed trimodal precipitate distribution. • Formation, dissolution and (slow) kinetics of small γ′ precipitates was determined. • Equilibrium volume fraction of γ′ phase is significantly higher than 45%. • The small γ′ precipitates arise regardless the application of the mechanical load. -- Abstract: Nickel base superalloy IN738LC has been studied after low-cycle fatigue by Small Angle Neutron Scattering (SANS). Samples subjected to high-temperature low-cycle fatigue were annealed at various temperatures to change the size and the distribution of precipitates. Ex and in situ SANS and TEM studies were performed. It was found that additional precipitates are formed either during slow cooling from high temperatures or after reheating above 570 °C. Their size and distribution were evaluated. The precipitates arise regardless the application of the mechanical load. Nevertheless, these small precipitates influence low-cycle fatigue resistance. From the SANS data, it can be also deduced that the equilibrium volume fraction of γ′-precipitates at temperatures from room temperature to 825 °C is significantly higher than 45%. The kinetics of formation of small and medium-size γ′ precipitates at 700 and 800 °C was determined as well.

  7. Effects of cobalt in nickel-base superalloys

    Science.gov (United States)

    Tien, J. K.; Jarrett, R. N.

    1983-01-01

    The role of cobalt in a representative wrought nickel-base superalloy was determined. The results show cobalt affecting the solubility of elements in the gamma matrix, resulting in enhanced gamma' volume fraction, in the stabilization of MC-type carbides, and in the stabilization of sigma phase. In the particular alloy studied, these microstructural and microchemistry changes are insufficient in extent to impact on tensile strength, yield strength, and in the ductilities. Depending on the heat treatment, creep and stress rupture resistance can be cobalt sensitive. In the coarse grain, fully solutioned and aged condition, all of the alloy's 17% cobalt can be replaced by nickel without deleteriously affecting this resistance. In the fine grain, partially solutioned and aged condition, this resistance is deleteriously affected only when one-half or more of the initial cobalt content is removed. The structure and property results are discussed with respect to existing theories and with respect to other recent and earlier findings on the impact of cobalt, if any, on the performance of nickel-base superalloys.

  8. Failure mechanisms of superhard materials when cutting superalloys

    International Nuclear Information System (INIS)

    Focke, A.E.; Westermann, F.E.; Ermi, A.; Yavelak, J.; Hoch, M.

    1975-01-01

    The present research studies the reasons for the failure of tungsten carbide tools while cutting superalloys. There is a continuous layer of the superalloy in the bottom of the crater which from time to time is torn away locally, taking tungsten carbide crystal with it. Under recommended cutting conditions a plateau (unworn cutting surface) separates the crater from the cutting edge of the tool when cutting AISI 4340. This plateau is totally absent in all cutting of Inconel 718, even in short, two-minute tests. The crater intersects the cutting edge--only a thin wedge of carbide is left which either breaks off or deforms and wears very rapidly. Temperature measurements carried out by use of an infrared detector aimed on the corner of the tungsten carbide indicate at recommended speeds a sharp rise of the temperature at the beginning of the cutting operation, then a steady-state very slow increase as the cutting continues, and finally just before tool failure a very rapid increase in the temperature again. Scanning and replica electron microscopy through the crater and flank face shows that both under the crater and in the back of the cutting edge a fairly deep layer of ''disturbed metal'' exists in which the tungsten carbide grains are much smaller and have much more rounded edges than in the original material. 10 figures, 4 tables

  9. Microstrain evolution during creep of a high volume fraction superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Ma, S. [Materials Department, New Mexico Tech, Socorro, NM 87801 (United States); Brown, D. [Los Alamos National Laboratory, Los Alamos, NM (United States); Bourke, M.A.M. [Los Alamos National Laboratory, Los Alamos, NM (United States); Daymond, M.R. [Rutherford Appleton Laboratory, ISIS Facility, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Majumdar, B.S. [Materials Department, New Mexico Tech, Socorro, NM 87801 (United States)]. E-mail: majumdar@nmt.edu

    2005-06-15

    The creep of superalloys containing a high volume fraction of {gamma}' phase is significantly influenced by initial misfit and by the evolution of internal stresses. An in situ neutron diffraction technique was used to monitor elastic microstrains in a polycrystalline superalloy, CM247 LC. The misfit was nearly zero at room temperature and it increased to -0.17% at 900 deg. C. These values are rationalized in terms of thermal mismatch using an eigenstrain formulation and a simple formula is derived to relate the thermal mismatch to the misfit strain. During creep at 425 MPa at 900 deg. C, the material exhibited primarily tertiary behavior. For grains with [0 0 1] axis close to the loading direction, the elastic microstrain in the loading direction increased with creep time for the {gamma}' phase, whereas the opposite occurred for the {gamma} phase. These results are explained in terms of constrained deformation in the narrow {gamma} channels and by an interface dislocation buildup. TEM analysis of the crept microstructure provides evidence of the interface dislocation network.

  10. The effect of refurbishing a UK steel plant on PM10 metal composition and ability to induce inflammation

    Directory of Open Access Journals (Sweden)

    Maynard Robert L

    2005-05-01

    Full Text Available Abstract Background In the year 2000 Corus closed its steel plant operations in Redcar, NE of England temporarily for refurbishment of its blast furnace. This study investigates the impact of the closure on the chemical composition and biological activity of PM10 collected in the vicinity of the steel plant. Methods The metal content of PM10 samples collected before during and after the closure was measured by ICP-MS in order to ascertain whether there was any significant alteration in PM10 composition during the steel plant closure. Biological activity was assessed by instillation of 24 hr PM10 samples into male Wistar rats for 18 hr (n = 6. Inflammation was identified by the cellular and biochemical profile of the bronchoalveolar lavage fluid. Metal chelation of PM10 samples was conducted using Chelex beads prior to treatment of macrophage cell line, J774, in vitro and assessment of pro-inflammatory cytokine expression. Results The total metal content of PM10 collected before and during the closure period were similar, but on reopening of the steel plant there was a significant 3-fold increase (p 10 collected during the reopened period, as well as significant increases in albumin (p 10 from the pre-closure and closure periods did not induce any significant alterations in inflammation or lung damage. The soluble and insoluble extractable PM10 components washed from the reopened period both induced a significant increase in neutrophil cell number (p 10 from the re-opened period stimulated J774 macrophages to generate TNF-α protein and this was significantly prevented by chelating the metal content of the PM10 prior to addition to the cells. Conclusion PM10-induced inflammation in the rat lung was related to the concentration of metals in the PM10 samples tested, and activity was found in both the soluble and insoluble fractions of the particulate pollutant.

  11. Refurbishment and modification of existing protective shipping packages (for 30-inch UF{sub 6} cylinders) per USDOT specification No. USA-DOT-21PF-1A

    Energy Technology Data Exchange (ETDEWEB)

    Housholder, W.R. [Nuclear Containers, Incorporated, Elizabethton, TN (United States)

    1991-12-31

    This paper addresses the refurbishment procedures for existing shipping containers for 30-inch diameter UF{sub 6} cylinders in accordance with DOT Specification 21PF-1 and the criteria used to determine rejection when such packages are unsuitable for refurbishment.

  12. Near-surface residual stresses and microstructural changes after turning of a nickel-based superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Schlauer, Christian

    2003-07-01

    Nickel-based superalloys are precipitation hardened alloys with complex compositions. They are used in aircraft engines and land-based gas turbines in load bearing structural components that are exposed to high temperatures. Failure mechanisms in this environment are high and low cycle fatigue, creep, and corrosion. During manufacturing, residual stresses are often introduced into the material due to inhomogeneous plastic deformations, both intentionally and unintentionally. One such manufacturing process is metal cutting, which introduces residual stresses in the surface layer. The stress state in the near-surface zone of components is of special interest as the surface often experiences peak loads and cracks have their starting point there. In this thesis, near-surface residual stress distributions and microstructural changes are studied in the nickel-based superalloy Inconel 718 for two different turning operations, face grooving and facing. Process variables are in both cases cutting speed and feed that have been varied between (10 and 1200) m/min and (0.01 and 0.5) mm, respectively. The first turning technique face grooving, which gives cutting conditions similar to orthogonal cutting, showed a clear dependency of the residual stresses on the cutting speed. The tensile stress at the surface, the maximum compressive stress below the surface, and the thickness of the affected layer increase with increasing cutting speed. The tensile stresses are constrained to a thin surface layer and compressive residual stresses below the surface dominate the depth profile of the residual stresses. Only at low cutting speed, residual stresses were largely avoided. The second turning technique facing confirmed the dependency of the residual stresses on the cutting speed and revealed a similar dependency on the feed. Microstructural investigations of near-surface cross-sections by means of transmission electron microscopy showed a zone where the grains had undergone plastic

  13. Advanced Scale Bridging Microstructure Analysis of Single Crystal Ni-Base Superalloys

    Czech Academy of Sciences Publication Activity Database

    Parsa, A. B.; Wollgramm, P.; Buck, H.; Somsen, C.; Kostka, A.; Povstugar, I.; Choi, P.-P.; Raabe, D.; Dlouhý, Antonín; Müller, J.; Spiecker, E.; Demtroder, K.; Schreuer, J.; Neuking, K.; Eggeler, G.

    2015-01-01

    Roč. 17, č. 2 (2015), s. 216-230 ISSN 1438-1656 Institutional support: RVO:68081723 Keywords : High temperature materials * Nickel based superalloys * EPMA * HRTEM Subject RIV: JG - Metallurgy Impact factor: 1.817, year: 2015

  14. High Temperature Degradation of Powder-processed Ni-based Superalloy

    Czech Academy of Sciences Publication Activity Database

    Luptáková, Natália; Pizúrová, Naděžda; Roupcová, Pavla; Dymáček, Petr

    2015-01-01

    Roč. 22, č. 2 (2015), s. 85-94 ISSN 1335-0803 Institutional support: RVO:68081723 Keywords : powder materials * polycrystalline Ni-based superalloy * creep machine grips * oxidation Subject RIV: JG - Metallurgy

  15. High temperature properties of polycrystalline γ"'-strengthened cobalt-base superalloys

    International Nuclear Information System (INIS)

    Bauer, Alexander

    2016-01-01

    The recent discovery of a stable γ"'-phase in Co-based superalloys opened up a pathway for the development of a new high temperature material class, which is similar in microstructure and properties to the modern γ"'-hardened Ni-based superalloys. In this work, the first attempt was done to check the influence of several for Ni-based superalloys typical alloying elements on the properties of the new Co-based superalloys. It became clear that the basic characteristics of the first experimental alloys are similar to those of the γ"'-hardened Ni-based alloys. The results of the multinary experimental alloys show that, based on the insight gained so far, targeted alloy development is possible. These materials have the potential to be used as disc materials in turbines.

  16. Nickel-base superalloy powder metallurgy: state-of-the-art

    International Nuclear Information System (INIS)

    Allen, M.M.; Athey, R.L.; Moore, J.B.

    1975-01-01

    Development of powder metallurgical methods for fabrication of Ni-base superalloy turbine engine disks is reviewed. Background studies are summarized and current state-of-art is discussed for the F100 jet engine, advanced applications, and forging processes

  17. Recovery of creep properties of the nickel-base superalloy nimonic 105

    CSIR Research Space (South Africa)

    Girdwood, RB

    1996-01-01

    Full Text Available Uniaxial constant stress creep tests were performed on the wrought nickel-base superalloy Nimonic 105. Entire creep curves were recorded and curve shapes analysed using the Theta Projection Concept. Rejuventive procedures were applied to pre...

  18. Microstructural studies of carbides in MAR-M247 nickel-based superalloy

    Science.gov (United States)

    Szczotok, A.; Rodak, K.

    2012-05-01

    Carbides play an important role in the strengthening of microstructures of nickel-based superalloys. Grain boundary carbides prevent or retard grain-boundary sliding and make the grain boundary stronger. Carbides can also tie up certain elements that would otherwise promote phase instability during service. Various types of carbides are possible in the microstructure of nickel-based superalloys, depending on the superalloy composition and processing. In this paper, scanning electron and scanning transmission electron microscopy studies of carbides occurring in the microstructure of polycrystalline MAR-M247 nickel-based superalloy were carried out. In the present work, MC and M23C6 carbides in the MAR-M247 microstructure were examined.

  19. Design of high entropy alloys based on the experience from commercial superalloys

    Science.gov (United States)

    Wang, Z.; Huang, Y.; Wang, J.; Liu, C. T.

    2015-01-01

    High entropy alloys (HEAs) have been drawing increasing attention recently and gratifying results have been obtained. However, the existing metallurgic rules of HEAs could not provide specific information of selecting candidate alloys for structural applications. Our brief survey reveals that many commercial superalloys have medium and even to high configurational entropies. The experience of commercial superalloys provides a clue for helping us in the development of HEAs for structural applications.

  20. Effects of cutting parameters on machinability characteristics of Ni-based superalloys: a review

    Directory of Open Access Journals (Sweden)

    Kaya Eren

    2017-12-01

    Full Text Available Nickel based superalloys offer high strength, corrosion resistance, thermal stability and superb thermal fatigue properties. However, they have been one of the most difficult materials to machine due to these properties. Although we are witnessing improved machining strategies with the developing machining, tooling and inspection technologies, machining of nickel based superalloys is still a challenging task due to in-process strains and post process part quality demands.

  1. Predicting the morphologies of {\\gamma}' precipitates in cobalt-based superalloys

    OpenAIRE

    Jokisaari, Andrea M.; Naghavi, Shahab S.; Wolverton, Chris; Voorhees, Peter W.; Heinonen, Olle G.

    2017-01-01

    Cobalt-based alloys with {\\gamma}/{\\gamma}' microstructures have the potential to become the next generation of superalloys, but alloy compositions and processing steps must be optimized to improve coarsening, creep, and rafting behavior. While these behaviors are different than in nickel-based superalloys, alloy development can be accelerated by understanding the thermodynamic factors influencing microstructure evolution. In this work, we develop a phase field model informed by first-princip...

  2. The Effect of Forging Variables on the Supersolvus Heat-Treatment Response of Powder-Metallurgy Nickel-Base Superalloys

    Science.gov (United States)

    2014-12-01

    AFRL-RX-WP-JA-2015-0160 THE EFFECT OF FORGING VARIABLES ON THE SUPERSOLVUS HEAT-TREATMENT RESPONSE OF POWDER - METALLURGY NICKEL-BASE SUPERALLOYS... POWDER - METALLURGY NICKEL- BASE SUPERALLOYS (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6. AUTHOR...treatment (SSHT) of two powder - metallurgy , gamma–gamma prime superalloys, IN-100 and LSHR, was established. For this purpose, isothermal, hot

  3. An integrated design process for a zero-energy refurbishment prototype for post-war residential buildings in the Netherlands

    NARCIS (Netherlands)

    Konstantinou, T.; Klein, T.; Guerra Santin, O.; Boess, S.U.; Silvester, S.

    2015-01-01

    Although refurbishment is a necessary step to reach the ambitious energy and decarbonisation targets for 2020 and 2050, which require an eventual reduction up to 90% in CO2 emissions, the rate of renovation is still relatively low. There is an increasing demand to upgrade both the physical condition

  4. Case study of a not-so-ordinary building - the Cowra Shire administration building ESD refurbishment

    Energy Technology Data Exchange (ETDEWEB)

    Halperin, M.; Arch, B. [Mahalath Halperin Architects Pty Ltd., Armidale (Australia). RAIA Country Division

    2004-07-01

    In refurbishing the Cowra Administration Building, Mahalath Halperin Architects transformed a concrete and glass building of the 1960s into an energy efficient and environmentally responsible building, yet looks to all intents and purposes like an 'ordinary building'. To some, it is simply a newer, nicer building with bright colours, open spaces and a pleasant work environment. But whilst not necessarily being outwardly different in issues of being a 'green building', the resultant building shows that there are many small yet easily achievable ways to be green. That it is not hard, and is in fact beneficial, to reduce energy consumption and overheads, take advantage of the sun (despite its poor orientation) and take on environmental responsibility. (orig.)

  5. Refurbishment implications on long-term waste management strategies at Point Lepreau

    International Nuclear Information System (INIS)

    Hickman, C.

    2011-01-01

    This paper discusses Point Lepreau Generating Station's waste management experiences during the Refurbishment outage. In short, Point Lepreau GS has been challenged during the outage due to the amount of low and intermediate level waste that has been generated compared to that which was expected, which has driven the need to develop a new waste management strategy in the middle of the outage. The paper presents an overview of pre-outage waste handling, what process changes and schedule changes occurred during the outage, and provides a discussion of the operational and financial consequences of those changes. Key issues highlighted by the paper include the need for adequate provision of waste management facilities during large outages, the importance of ensuring that contractors have a stake in waste minimization activities, and long term waste management implications that need to be considered for large outages.

  6. Start-up of Cirus after refurbishment outage and observations during approach to criticality

    International Nuclear Information System (INIS)

    Singh, Tej; Singh, Kanchhi; Sengupta, S.N.

    2004-10-01

    The report presents various physics related aspects of the startup of Cirus reactor after the prolonged refurbishment outage. The special nuclear instrumentation scheme adopted to ensure safe startup of the reactor is described. Salient observations made and physics measurements carried out during various approaches to criticality are covered. One of the significant observations concerned a major reactivity anomaly during the approach to criticality. After due investigations the cause of the anomaly was attributed to the inadvertent wetting of the graphite reflector which houses the reactor regulating and protection system ion chambers. The report also includes salient observations during raising of reactor power to high levels. The wet reflector also resulted in a significant difference measured between the thermal and neutronic power of the reactor. In view of the reactivity anomaly, the core reactivity variation with time was closely followed and compared with computations. As expected the reactivity anomaly reduced gradually with time. (author)

  7. Main refurbishment activities on electronic and electrical equipment for the FRG-1 research reactor

    International Nuclear Information System (INIS)

    Blom, K.H.; Krull, W.

    1997-01-01

    As GKSS intends to operate the research reactor FRG-1 safely and reliably for many years to come, the plant is constantly refurbished and upgraded both in the interests of safety and operational reasons. The following electronic and electrical systems have been replaced or improved since 1990: Information and signalling systems; Emergency power plant (permit applied for); External and internal lightning protection system; Reactor protection system (in part); Safety lighting; Alarm and staff locating system; Control room telephone system; Closed-circuit television system; Beam tube controls; Storage plant for radioactive liquid waste; Ambient dose rate measuring system; Meteorological measuring system; Control and measuring system for the primary cooling circuit; Control rod drives; Control rod control system; Soft start for the secondary pumps; Control and switching devices for the emergency power plant; Trailing cable installation for the reactor bridge; Main-voltage distribution systems/cable routes. (author). 13 figs, 1 tab

  8. Scout house in Koeniz - Refurbishment of the heating system; Pfadiheim Weiermatt, Sanierung Waermeversorgung - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Messerli, A. [Neuenschwander - Neutair AG, Berne (Switzerland); Jenni, H. [Heimverein Falkenstein, Koeniz (Switzerland)

    2004-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project carried out in Koeniz, Switzerland. The report examines how the energy situation at the local scout house was improved. The work included the refurbishment of the heating system using solar collectors, intelligently controlled heat pumps, a photovoltaics installation and even solar-powered street lighting. The project, which received a substantial echo from the general public, is described. The scouts were directly involved in the project and, in part, in the construction work. This, according to the authors, enhanced the educational aspect of the project. The report presents details on the various installations and is illustrated with schematics and photos. Also, the results of monitoring and measurements made are presented.

  9. Studies on phase kinetics of new superalloys

    International Nuclear Information System (INIS)

    Weisbrodt, A.; Penkalla, H.J.; Schubert, F.; Nickel, H.

    1990-08-01

    At the development of new ODS (Oxide-Dispersion-Strengthened) alloys for components being exposed to hot-gas temperatures nickel-base alloys and ODS alloys have been investigated. The experimental work mainly referred to phase investigations of thermally loaded samples. The addition of alloying elements will have a decisive influence on the γ'-phase fraction, γ'-lattice parameter, the morphology as well as the coarsening behaviour of the γ'-phase under temperature load. The main characteristics of ODS alloys are Y,Al-mixed oxides and microstructural inhomogenities. As for MA6000 a Time-Temperature-Precipitation diagram has been elaborated. By means of the improved computer programme PHASCALC for phase and N v (= average electron vacancy concentration) - value calculation many microstructural parameters such as the γ/γ'-misfit, the solution of the γ'-phase and melting temperatures can be determined. Tensile tests made at temperatures above 900deg C have shown that the strengthening parameters are dependent on alloy composition, temperature conditions, γ'-phase fraction and oxide dispersion content. (orig.) [de

  10. Choosing the Energy Sources Needed for Utilities in the Design and Refurbishment of Buildings

    Directory of Open Access Journals (Sweden)

    Pavel Atănăsoae

    2018-03-01

    Full Text Available This paper presents a method for choosing the energy sources that are needed for the following building utilities following building: lighting, domestic hot water, heating, ventilation, and air conditioning. The novelty of this paper consists of applying the concept of the energy hub and considering the cost of carbon dioxide emissions when selecting the available energy sources in the building’s location. The criterion for selecting the energy sources is the minimum overall cost of all forms of energy that are consumed in the building over its estimated lifetime. In order to estimate the overall costs, it is necessary to know the power that is installed and provided by the energy production technologies that are inside the building, as well as the capacity of energy that is required from outside energy sources. An office building that was proposed for refurbishment has been investigated as a case study. In the paper, we have analysed four scenarios. The results indicate that more favourable alternative solutions can be obtained compared to the traditional scenario (Scenario 4—heat and electricity by public utility networks. The overall costs are 46.17% (212,671 EUR lower in Scenario 1, 25.35% (116,770 EUR lower in Scenario 2, and 10.89% (50,150 EUR lower in Scenario 3. Additionally, the carbon dioxide emissions are 22.98% (49 tonnes CO2/year lower in Scenario 1 and 8.91% (19 tonnes CO2/year lower in Scenario 2. Thus, renewable energy sources can occupy a growing share of the total energy consumption of the building. The proposed algorithm can be used for both the refurbishment of existing buildings and the design of new buildings.

  11. A containment analysis for SBLOCA in the refurbished Wolsong-1 Nuclear Power Plant

    International Nuclear Information System (INIS)

    Kim, Tech-Mo; Park, Jong-Ho

    2011-01-01

    Highlights: → The CANDU safety analysis has been accomplished for the refurbished Wolsong-1 NPP. → GOTHIC and SMART-IST codes and new methodology are used for the containment analysis. → The parametric studies for Iodine Chemistry (IMOD-2) model are performed. → And, IMOD-2 model is very sensitive to paint thickness and dousing water pH. → The radioactive doses to the public in SBLOCA event are far below the acceptable limits. - Abstract: A small break leading to a loss of coolant accident (SBLOCA), being one of the topic accidents in the nuclear plant diagnosis in recent years, has been analysed and evaluated for the refurbished Wolsong-1 Nuclear Power Plant (NPP). The Industry Standard Toolset (IST) codes developed by CANDU (Canadian Deuterium Uranium reactor) Owners Group and updated models including design change parameters are applied newly to the event analyses. The GOTHIC code has been used for the containment thermal-hydraulic analysis of Wolsong-1. Also, the SMART-IST code fitted in the Iodine Chemistry (IMOD-2) model has been used to predict nuclide behavior within the containment considering various aspects. The IMOD-2 was incorporated into SMART-IST as a module dealing with chemical transformations and mass transfer of iodine species in containment. IMOD-2 model is very sensitive to paint and chemicals. The parametric studies for the IMOD-2 model are performed to decide the analysis value set. The iodine release amount increases as the paint thickness increases. But, the iodine release amount increases as the water pH (dousing and primary heat transport (PHT)) decreases. The developed containment analysis methodology and the results of SBLOCA without Emergency Coolant Injection (ECI) are presented herein. Under the most heat-up conditions, the radionuclide release from the failed fuel into the containment and subsequently to the environment is such that the radioactive doses to the public are below the acceptable limits.

  12. Refurbishment of PSI-Hotlaboratory to comply with requested safety standards after 40 years of operation

    International Nuclear Information System (INIS)

    Bart, G.; Hofer, R.; Wiezel, L.

    2001-01-01

    The PSI Hotlaboratory has started its operation in 1962. From the very beginning the hotcell wing served for handling and gross PIE analysis of reactor core internals and highly active material from accelerator target stations. In the radiochemistry wing micro structural and chemical analyses of small, highly active samples were subsequently performed with equipment installed in individual lead shielded cells. The radiochemistry wing also served for radiopharmaceutical nuclide dispatching and actinide ceramics preparation. Several constructions and building enlargements have been added since 1962 and similarly, the safety infrastructure was improved case wise. In the course of reevaluating the principal safety documentation for the Hotlaboratory, during 1994-95 it was realized that the building concept with its class A radioactive areas did not comply any more with modern safely standards, in particular with fire protection regulations and operator safety. In accident scenario analyses it was further demonstrated that radio nuclide release to the environment could cause intolerable health risks to the surrounding population. It was therefore decided to principally refurbish the building infrastructure particularly with respect to fire protection, media, and laboratory instrumentation and control. The chosen concept consists in adding a so called media installation corridor on top and along the radiochemistry wing from which the individual labs, on two floors are reached by vertical media access channels. Since the reconstruction outage time had to be minimized and there was not enough storage capacity to remove the whole Hotlaboratory equipment at once, a stepwise reconstruction was planned with separation of specified blocks of labs which are freed from samples (but still contain specially encapsulated, internally contaminated glove boxes and lead shielded cells) and which are accessed from the building outside, while the rest of the labs are still (or again) in

  13. Microstructure-sensitive Crystal Viscoplasticity for Ni-base Superalloys Targeting Long-term Creep-Fatigue Interaction Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Neu, Richard W.

    2017-09-30

    The aim of this project is to develop a microstructure-sensitive crystal viscoplasticity (CVP) model for single-crystal Ni-base superalloys to model the behavior of the material and components in the hot gas path sections of industrial gas turbines (IGT). Microstructure degradation associated with aging critical to predicting long-term creep-fatigue interactions will be embedded into the model through the γ' precipitate morphology evolution by coupling the coarsening drivers and kinetics into the constitutive equations of the CVP model. Model parameters will be determined using new experimental protocols that involve systematically artificially aging the alloy under different stress conditions to determine the relationship between the size and morphology g' precipitates on the creep and thermomechanical fatigue response.

  14. Investigation of selected thermo-physical properties in the Co-based superalloy: Experiment and application study

    Directory of Open Access Journals (Sweden)

    J. Kasala

    2010-01-01

    Full Text Available Thermo-physical properties are the critical input parameters in computational models of solidification and casting simulations. In thermodynamics, the enthalpy is quotient of thermodynamic potential of a system, which can be used to calculate the useful work obtainable from a closed thermodynamic system under constant pressure. Differential thermal analysis has been used to study melting and solidification paths in the cobalt based superalloy FSX-414. The temperature enthalpy curve was determined from differential thermal analysis curves obtained from solidification curves. A solidification simulation of a cobalt base multi-component alloy casting was carried out to predict cooling and shrinkage porosity in the casting of a turbine engine vane segment. The effect of latent heat on the heat transfer calculation was considered by enthalpy method.

  15. Microstructure-sensitive Crystal Viscoelasticity for Ni-base Superalloys Targeting Long-term Creep-Fatigue Interaction Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Neu, Richard W

    2016-09-30

    The aim of this project is to develop a microstructure-sensitive crystal viscoplasticity (CVP) model for single-crystal Ni-base superalloys to model the behavior of the material and components in the hot gas path sections of industrial gas turbines (IGT). Microstructure degradation associated with aging critical to predicting long-term creep-fatigue interactions will be embedded into the model through the γ' precipitate morphology evolution by coupling the coarsening drivers and kinetics into the constitutive equations of the CVP model. Model parameters will be determined using new experimental protocols that involve systematically artificially aging the alloy under different stress conditions to determine the relationship between the size and morphology g' precipitates on the creep and thermomechanical fatigue response.

  16. Small might be beautiful, but bigger performs better: Scale economies in “green” refurbishments of apartment housing

    International Nuclear Information System (INIS)

    Michelsen, Claus; Rosenschon, Sebastian; Schulz, Christian

    2015-01-01

    The energy efficiency of the residential housing stock plays a key role in strategies to mitigate climate change and global warming. In this context, it is frequently argued that private investment and the quality of thermal upgrades are too low in the light of the challenges faced and the potential energy cost savings. While many authors address the potential barriers for investors to increase energy efficiency, studies on the capabilities of different investors to reduce energy requirements of their property are scarce. This study investigates potential advantages of housing company's size, i.e. economies of scale, economies of scope and institutional learning in thermal upgrades of residential housing. Based on unique data on energy consumption in 102,307 apartment buildings in Germany, we present new evidence for the advantages and disadvantages of a housing company's size in “green” retrofitting projects. Our estimations show, that large housing companies outperform private landlords by far in high effort refurbishment projects. In contrast, private landlords appear to have advantages in low effort, incremental refurbishment activities. We demonstrate that a substantial share of the advantages of larger firms can be associated with specialization (i.e. repeated projects). The results offer new options for policy makers to refine the support schemes toward a low carbon housing stock. - Highlights: • First study to analyze the effects of housing companies size on “green” refurbishment • Economies of scale, scope and learning all affect energy efficiency refurbishments. • Specialization on distinct refurbishments influences outcome of thermal upgrades. • Analysis based on a large and unique sample of apartment buildings in Germany

  17. Laser aided direct metal deposition of Inconel 625 superalloy: Microstructural evolution and thermal stability

    International Nuclear Information System (INIS)

    Dinda, G.P.; Dasgupta, A.K.; Mazumder, J.

    2009-01-01

    Direct metal deposition technology is an emerging laser aided manufacturing technology based on a new additive manufacturing principle, which combines laser cladding with rapid prototyping into a solid freeform fabrication process that can be used to manufacture near net shape components from their CAD files. In the present study, direct metal deposition technology was successfully used to fabricate a series of samples of the Ni-based superalloy Inconel 625. A high power CO 2 laser was used to create a molten pool on the Inconel 625 substrate into which an Inconel 625 powder stream was delivered to create a 3D object. The structure and properties of the deposits were investigated using optical and scanning electron microscopy, X-ray diffraction and microhardness test. The microstructure has been found to be columnar dendritic in nature, which grew epitaxially from the substrate. The thermal stability of the dendritic morphology was investigated in the temperature range 800-1200 deg. C. These studies demonstrate that Inconel 625 is an attractive material for laser deposition as all samples produced in this study are free from relevant defects such as cracks, bonding error and porosity.

  18. Conductivity Profile Determination by Eddy Current for Shot Peened Superalloy Surfaces Toward Residual Stress Assessment

    International Nuclear Information System (INIS)

    Shen, Y.; Lo, C. C. H.; Frishman, A. M.; Lee, C.; Nakagawa, N.

    2007-01-01

    This paper describes an eddy current model-based method for inverting near-surface conductivity deviation profiles of surface treated materials from swept-high frequency eddy current (SHFEC) data. This work forms part of our current research directed towards the development of an electromagnetic nondestructive technique for assessing residual stress of shot-peened superalloy components. The inversion procedure is based on the use of a parameterized function to describe the near-surface conductivity as a function of depth for a shot-peened surface, and the laterally uniform multi-layer theory of Cheng, Dodd and Deeds to calculate the resulting coil impedance deviations. The convergence of the inversion procedure has been tested against synthesized eddy current data. As a demonstration, the conductivity deviation profiles of a series of Inconel 718 specimens, shot peened at various Almen intensities, have been obtained by inversion. Several consistency tests were conducted to examine the reliability of the inverted conductivity profiles. The results show that conductivity deviation profiles can be reliably determined from SHFEC data within the accuracy of the current measurement system

  19. Laser aided direct metal deposition of Inconel 625 superalloy: Microstructural evolution and thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Dinda, G.P., E-mail: dindag@focushope.edu [Center for Advanced Technologies, Focus: HOPE, Detroit, MI 48238 (United States); Center for Laser Aided Intelligent Manufacturing, University of Michigan, Ann Arbor, MI 48109 (United States); Dasgupta, A.K. [Center for Advanced Technologies, Focus: HOPE, Detroit, MI 48238 (United States); Mazumder, J. [Center for Laser Aided Intelligent Manufacturing, University of Michigan, Ann Arbor, MI 48109 (United States)

    2009-05-25

    Direct metal deposition technology is an emerging laser aided manufacturing technology based on a new additive manufacturing principle, which combines laser cladding with rapid prototyping into a solid freeform fabrication process that can be used to manufacture near net shape components from their CAD files. In the present study, direct metal deposition technology was successfully used to fabricate a series of samples of the Ni-based superalloy Inconel 625. A high power CO{sub 2} laser was used to create a molten pool on the Inconel 625 substrate into which an Inconel 625 powder stream was delivered to create a 3D object. The structure and properties of the deposits were investigated using optical and scanning electron microscopy, X-ray diffraction and microhardness test. The microstructure has been found to be columnar dendritic in nature, which grew epitaxially from the substrate. The thermal stability of the dendritic morphology was investigated in the temperature range 800-1200 deg. C. These studies demonstrate that Inconel 625 is an attractive material for laser deposition as all samples produced in this study are free from relevant defects such as cracks, bonding error and porosity.

  20. Additive Manufacturing of Nickel-Base Superalloy IN100 Through Scanning Laser Epitaxy

    Science.gov (United States)

    Basak, Amrita; Das, Suman

    2018-01-01

    Scanning laser epitaxy (SLE) is a laser powder bed fusion (LPBF)-based additive manufacturing process that uses a high-power laser to consolidate metal powders facilitating the fabrication of three-dimensional objects. In the present study, SLE is used to produce samples of IN100, a high-γ' non-weldable nickel-base superalloy on similar chemistry substrates. A thorough analysis is performed using various advanced material characterization techniques such as high-resolution optical microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and Vickers microhardness measurements to characterize and compare the quality of the SLE-fabricated IN100 deposits with the investment cast IN100 substrates. The results show that the IN100 deposits have a finer γ/γ' microstructure, weaker elemental segregation, and higher microhardness compared with the substrate. Through this study, it is demonstrated that the SLE process has tremendous potential in the repair and manufacture of gas turbine hot-section components.

  1. Micromechanical Behavior of Single-Crystal Superalloy with Different Crystal Orientations by Microindentation

    Directory of Open Access Journals (Sweden)

    Jinghui Li

    2015-01-01

    Full Text Available In order to investigate the anisotropic micromechanical properties of single-crystal nickel-based superalloy DD99 of four crystallographic orientations, (001, (215, (405, and (605, microindentation test (MIT was conducted with different loads and loading velocities by a sharp Berkovich indenter. Some material parameters reflecting the micromechanical behavior of DD99, such as microhardness H, Young’s modulus E, yield stress σy, strain hardening component n, and tensile strength σb, can be obtained from load-displacement relations. H and E of four different crystal planes evidently decrease with the increase of h. The reduction of H is due to dislocation hardening while E is related to interplanar spacing and crystal variable. σy of (215 is the largest among four crystal planes, followed by (605, and (001 has the lowest value. n of (215 is the lowest, followed by (605, and that of (001 is the largest. Subsequently, a simplified elastic-plastic material model was employed for 3D microindentation simulation of DD99 with various crystal orientations. The simulation results agreed well with experimental, which confirmed the accuracy of the simplified material model.

  2. Low heat input welding of nickel superalloy GTD-111 with Inconel 625 filler metal

    Energy Technology Data Exchange (ETDEWEB)

    Athiroj, Athittaya; Wangyao, Panyawat; Hartung, Fritz; Lothongkum, Gobboon [Chulalongkorn Univ., Bangkok (Thailand). Dept. of Metallurgical Engineering

    2018-03-01

    GTD-111 precipitation-strengthened nickel-based superalloy is widely used in blades of gas turbine engines which operate at high temperature and in a hot localized corrosion atmosphere. After long-term exposure to high temperature, γ' precipitate is known to exhibit catastrophic changes in size and distribution which cause deterioration of its properties and failure of the component. In this study, a damaged blade removed from a land-based gas turbine generator was subjected to nonpre-heat-treated GTAW and laser welding repair with various welding powers in the range of 135 to 295 J x mm{sup -1}, followed by post-weld heat treatment (PWHT) at 1473 K for 7200 s and strain aging at 1118 K for 86 400 s. Results show no significant relationship between welding powers, size and area fraction of the γ' precipitate in the fcc γ matrix in both GTAW and laser-welded specimens. The final γ' precipitate size and distribution depend mainly on PWHT parameters as γ' precipitates in all GTAW and laser welded specimens showed similar size and area fraction independently of the heat input from welding. Unmixed zones are observed in all laser welding specimens which may cause preferential weld corrosion during service. Microcrack occurrence due to welding and PWHT processes is also discussed.

  3. Fiber laser welding of nickel based superalloy Inconel 625

    Science.gov (United States)

    Janicki, Damian M.

    2013-01-01

    The paper describes the application of single mode high power fiber laser (HPFL) for the welding of nickel based superalloy Inconel 625. Butt joints of Inconel 625 sheets 0,8 mm thick were laser welded without an additional material. The influence of laser welding parameters on weld quality and mechanical properties of test joints was studied. The quality and mechanical properties of the joints were determined by means of tensile and bending tests, and micro hardness tests, and also metallographic examinations. The results showed that a proper selection of laser welding parameters provides non-porous, fully-penetrated welds with the aspect ratio up to 2.0. The minimum heat input required to achieve full penetration butt welded joints with no defect was found to be 6 J/mm. The yield strength and ultimate tensile strength of the joints are essentially equivalent to that for the base material.

  4. Computer aided design of nickel-base superalloys

    International Nuclear Information System (INIS)

    Lawrence, P.J.

    1988-01-01

    This paper describes a computer aided design process for Ni-base superalloys developed and employed at ASEA Brown Boveri. The technique involves a series of modules each of which predicts a particular property of a hypothetical new composition. In the first stage of the development of this design techniques modules were produced to predict phase stability, using PHACOMP, and high temperature creep strength and hot corrosion resistance, using multiple linear regression equations derived from the data in the literature. Alloys designed using these technique are also discussed and, in particular, shortcomings of the design process are highlighted. This information was then used to produce a revamped design methodology involving extra modules, including prediction of an alloy's gamma-prime content. (orig.)

  5. N18, powder metallurgy superalloy for disks: Development and applications

    Energy Technology Data Exchange (ETDEWEB)

    Guedou, J.Y.; Lautridou, J.C.; Honnorat, Y. (SNECMA, Evry (France). Materials and Processes Dept.)

    1993-08-01

    The preliminary industrial development of a powder metallurgy (PM) superalloy, designated N18, for disk applications has been completed. This alloy exhibits good overall mechanical properties after appropriate processing of the material. These properties have been measured on both isothermally forged and extruded billets, as well as on specimens cut from actual parts. The temperature capability of the alloy is about 700 C for long-term applications and approximately 750 C for short-term use because of microstructural instability. Further improvements in creep and crack propagation properties, without significant reduction in tensile strength, are possible through appropriate thermomechanical processing, which results in a large controlled grain size. Spin pit tests on subscale disks have confirmed that the N18 alloy has a higher resistance than PM Astrology and is therefore an excellent alloy for modern turbine disk applications.

  6. Electron-microscopic investigations of dispersion-strengthened superalloys

    International Nuclear Information System (INIS)

    Schroeder, J.H.; Arzt, E.

    1988-01-01

    Oxide dispersion strengthened (ODS) superalloys possess a high creep strength up to temperatures above 1000 0 C. This is due to a fine dispersion of incoherent Y 2 O 3 particles in connection with a highly elongated grain structure. To investigate the production and properties of ODS alloys, the grain structure was studied and the shape and distribution of dispersoids were characterized after each of the various production steps. Because the interactions between lattice dislocations and dispersoids control the deformation behaviour at high temperatures, the dislocation-dispersoid configurations in crept specimens have been studied by a TEM stereo technique and under weak-beam conditions. It was possible to detect strain fields around the dispersoids using TEM. The results lead to an improved understanding of dispersion strengthening at high temperatures and provide guidelines for the optimum use of this strengthening mechanism. (orig.) [de

  7. Effect of heat treatment on the microstructure, texture and elastic anisotropy of the nickel-based superalloy CM247LC processed by selective laser melting

    International Nuclear Information System (INIS)

    Muñoz-Moreno, R.; Divya, V.D.; Driver, S.L.; Messé, O.M.D.M.; Illston, T.; Baker, S.; Carpenter, M.A.; Stone, H.J.

    2016-01-01

    Selective laser melting (SLM) of nickel-based superalloys is of great interest for the aerospace industry due to its capability for producing components with complex geometries. However, an improved understanding of the effect of SLM and subsequent post deposition heat treatments on the microstructure and mechanical properties is required to ensure that components with good structural integrity are produced. In this study, the microstructure, texture and elastic anisotropy of the nickel-based superalloy, CM247LC, in the as-SLM and heat-treated states have been analysed. The as-SLM microstructure showed fine elongated cells with a preferential alignment of <001> along the build direction and a significant intercellular misorientation. Heat treatments at temperatures below 1230 °C resulted in a progressive recovery of the microstructure, whilst heat treatments above this temperature gave rise to a recrystallised microstructure. The extent to which nucleation and growth of the γ′ precipitates and secondary particles were affected by increasing the heat treatment temperature was also characterised. The bulk elastic anisotropy of all samples was measured by resonant ultrasound spectroscopy (RUS) and was found to be consistent with the local textures obtained by electron backscatter diffraction (EBSD). It was observed that the initially strong elastic anisotropy exhibited by the as-SLM material was significantly reduced in the recrystallised samples, although some anisotropy was retained as a result of their elongated grain microstructures.

  8. Effect of heat treatment on the microstructure, texture and elastic anisotropy of the nickel-based superalloy CM247LC processed by selective laser melting

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz-Moreno, R., E-mail: rociomunozmoreno@gmail.com [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Divya, V.D. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Driver, S.L. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ (United Kingdom); Messé, O.M.D.M. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Illston, T.; Baker, S. [Materials Solutions, Unit 8, Great Western Business Park, McKenzie Way, Worcester WR4 9GN (United Kingdom); Carpenter, M.A. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ (United Kingdom); Stone, H.J. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

    2016-09-30

    Selective laser melting (SLM) of nickel-based superalloys is of great interest for the aerospace industry due to its capability for producing components with complex geometries. However, an improved understanding of the effect of SLM and subsequent post deposition heat treatments on the microstructure and mechanical properties is required to ensure that components with good structural integrity are produced. In this study, the microstructure, texture and elastic anisotropy of the nickel-based superalloy, CM247LC, in the as-SLM and heat-treated states have been analysed. The as-SLM microstructure showed fine elongated cells with a preferential alignment of <001> along the build direction and a significant intercellular misorientation. Heat treatments at temperatures below 1230 °C resulted in a progressive recovery of the microstructure, whilst heat treatments above this temperature gave rise to a recrystallised microstructure. The extent to which nucleation and growth of the γ′ precipitates and secondary particles were affected by increasing the heat treatment temperature was also characterised. The bulk elastic anisotropy of all samples was measured by resonant ultrasound spectroscopy (RUS) and was found to be consistent with the local textures obtained by electron backscatter diffraction (EBSD). It was observed that the initially strong elastic anisotropy exhibited by the as-SLM material was significantly reduced in the recrystallised samples, although some anisotropy was retained as a result of their elongated grain microstructures.

  9. Microstructural analysis of laser weld fusion zone in Haynes 282 superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Osoba, L.O. [Department of Mechanical and Manufacturing Engineering, University of Manitoba, Winnipeg, Manitoba, R3T 5V6 (Canada); Ding, R.G. [Department of Metallurgy and Materials Engineering, University of Birmingham, Birmingham B15 2TT (United Kingdom); Ojo, O.A., E-mail: ojo@cc.umanitoba.ca [Department of Mechanical and Manufacturing Engineering, University of Manitoba, Winnipeg, Manitoba, R3T 5V6 (Canada)

    2012-03-15

    Analytical electron microscopy and spectroscopy analyses of the fusion zone (FZ) microstructure in autogenous laser beam welded Haynes 282 (HY 282) superalloy were performed. The micro-segregation patterns observed in the FZ indicate that Co, Cr and Al exhibited a nearly uniform distribution between the dendrite core and interdendritic regions while Ti and Mo were rejected into the interdendritic liquid during the weld solidification. Transmission electron diffraction analysis and energy dispersive X-ray microanalysis revealed the second phase particles formed along the FZ interdendritic region to be Ti-Mo rich MC-type carbide particles. Weld FZ solidification cracking, which is sometimes associated with the formation of {gamma}-{gamma}' eutectic in {gamma}' precipitation strengthened nickel-base superalloys, was not observed in the HY 282 superalloy. Modified primary solidification path due to carbon addition in the newly developed superalloy is used to explain preclusion of weld FZ solidification cracking in the material. - Highlights: Black-Right-Pointing-Pointer A newly developed superalloy was welded by CO{sub 2} laser beam joining technique. Black-Right-Pointing-Pointer Electron microscopy characterization of the weld microstructure was performed. Black-Right-Pointing-Pointer Identified interdendritic microconstituents consist of MC-type carbides. Black-Right-Pointing-Pointer Modification of primary solidification path is used to explain cracking resistance.

  10. Effect of tensile mean stress on fatigue behavior of single-crystal and directionally solidified superalloys

    Science.gov (United States)

    Kalluri, Sreeramesh; Mcgaw, Michael A.

    1990-01-01

    Two nickel base superalloys, single crystal PWA 1480 and directionally solidified MAR-M 246 + Hf, were studied in view of the potential usage of the former and usage of the latter as blade materials for the turbomachinery of the space shuttle main engine. The baseline zero mean stress (ZMS) fatigue life (FL) behavior of these superalloys was established, and then the effect of tensile mean stress (TMS) on their FL behavior was characterized. At room temperature these superalloys have lower ductilities and higher strengths than most polycrystalline engineering alloys. The cycle stress-strain response was thus nominally elastic in most of the fatigue tests. Therefore, a stress range based FL prediction approach was used to characterize both the ZMS and TMS fatigue data. In the past, several researchers have developed methods to account for the detrimental effect of tensile mean stress on the FL for polycrystalline engineering alloys. However, the applicability of these methods to single crystal and directionally solidified superalloys has not been established. In this study, these methods were applied to characterize the TMS fatigue data of single crystal PWA 1480 and directionally solidified MAR-M 246 + Hf and were found to be unsatisfactory. Therefore, a method of accounting for the TMS effect on FL, that is based on a technique proposed by Heidmann and Manson was developed to characterize the TMS fatigue data of these superalloys. Details of this method and its relationship to the conventionally used mean stress methods in FL prediction are discussed.

  11. Microstructural analysis of laser weld fusion zone in Haynes 282 superalloy

    International Nuclear Information System (INIS)

    Osoba, L.O.; Ding, R.G.; Ojo, O.A.

    2012-01-01

    Analytical electron microscopy and spectroscopy analyses of the fusion zone (FZ) microstructure in autogenous laser beam welded Haynes 282 (HY 282) superalloy were performed. The micro-segregation patterns observed in the FZ indicate that Co, Cr and Al exhibited a nearly uniform distribution between the dendrite core and interdendritic regions while Ti and Mo were rejected into the interdendritic liquid during the weld solidification. Transmission electron diffraction analysis and energy dispersive X-ray microanalysis revealed the second phase particles formed along the FZ interdendritic region to be Ti–Mo rich MC-type carbide particles. Weld FZ solidification cracking, which is sometimes associated with the formation of γ–γ' eutectic in γ' precipitation strengthened nickel-base superalloys, was not observed in the HY 282 superalloy. Modified primary solidification path due to carbon addition in the newly developed superalloy is used to explain preclusion of weld FZ solidification cracking in the material. - Highlights: ► A newly developed superalloy was welded by CO 2 laser beam joining technique. ► Electron microscopy characterization of the weld microstructure was performed. ► Identified interdendritic microconstituents consist of MC-type carbides. ► Modification of primary solidification path is used to explain cracking resistance.

  12. Influence of Short-time Oxidation on Corrosion Properties of Directionally Solidified Superalloys with Different Orientations

    Directory of Open Access Journals (Sweden)

    MA Luo-ning

    2016-07-01

    Full Text Available In order to investigate the corrosion performance on intersecting and longitudinal surfaces of unoxidized and oxidized directionally solidified superalloys, Ni-base directionally solidified superalloy DZ125 and Co-base directionally solidified superalloy DZ40M were selected. Oxidation behavior on both alloys with different orientations was investigated at 1050℃ at different times, simulating the oxidation process of vanes or blades in service; subsequent electrochemical performance in 3.5%NaCl aqueous solution was studied on two orientations of unoxidized and oxidized alloys, simulating the corrosion process of superalloy during downtime. The results show that grain boundaries and sub-boundaries of directionally solidified superalloys are susceptible to corrosion and thus longitudinal surface with lower area fraction of grain boundaries has higher corrosion resistance. Compared to intersecting surface of alloys, the structure of grain boundaries of longitudinal surface is less conducive to diffusion and thus the oxidation rate on longitudinal surface is lower. Formation of oxide layers on alloys after short-time oxidation provides protective effect and enhances the corrosion resistance.

  13. Constitutive modeling of a nickel base superalloy -with a focus on gas turbine applications

    Energy Technology Data Exchange (ETDEWEB)

    Almroth, Per

    2003-05-01

    Gas turbines are used where large amounts of energy is needed, typically as engines in aircraft, ferries and power plants. From an efficiency point of view it is desirable to increase the service temperature as much as possible. One of the limiting factors is then the maximum allowable metal temperatures in the turbine stages, primarily in the blades of the first stage, that are exposed to the highest gas temperatures. Specially designed materials are used to cope with these severe conditions, such as the nickel base superalloy IN792. In order to be able to design the components for higher temperatures and tighter tolerances, a detailed understanding and computationel models of the material behaviour is needed. The models presented in this work have been developed with the objective of being physically well motivated, and with the intention of avoiding excessive numbers of parameters. The influence of the parameters should also be as easy as possible to interpret. The models are to describe the behaviour of IN792, under conditions typically found for a gas turbine blade. Specifically the high- and intermediate temperature isothermal modelling of IN792 have been addressed. One main issue when characterising the material and calibrating the models is the use of relevant tests, that are representative of component conditions. Therefore isothermal tests with an eye on the typical environment of a turbine blade have been planned and performed. Using numerical optimization techniques the material parameters for the isothermal behaviour of IN792 at 650 deg and 850 deg have been estimated. The good overall calibration results for these specific temperatures, using the presented modeling concept and nonstandard constitutive tests, suggests that the model can describe the behaviour of IN792 in gas turbine hot part applications.

  14. Refurbishment of the transportation equipment, Task 3.08/04-10; Podzadatak 3.08/04-10 Remont transportnih uredjaja

    Energy Technology Data Exchange (ETDEWEB)

    Nikolic, M; Bratic, A [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    Transportation equipment at the RA reactor includes the bridge crane in the reactor hall, another smaller crane, bridge crane in spent fuel storage space, crane for handling the fuel containers n the room 099 and cart of the transportation channel. Regular testing and maintenance during reactor operation was not considered sufficient, and for that reason the repair and maintenance actions were done during the refurbishment of the reactor while it has been shut-down.

  15. Austro-Hungarian Public Building Refurbishment and Energy Efficiency Measures - A Case Study on a Public Building in Sarajevo

    Science.gov (United States)

    Salihbegović, Amira; Čaušević, Amir; Rustempašić, Nerman; Avdić, Dženis; Smajlović, Esad

    2017-10-01

    Among other pieces of architectural historical heritage in Sarajevo, and Bosnia-Herzegovina in general, the Austro-Hungarian architecture has preserved its original architectural, artistic and engineering characteristics. Both residential and public representative urban blocks, streets and squares are of distinguishable ambience in the architectural and urban image of the city and are testifying about our architectural past. A number of buildings is valorised and protected by law in terms of their architectural, artistic and historical value. In addition, these buildings have a distinct functional, ambiental, historical, and even aesthetical value. To make them last longer, refurbishment of these buildings is challenging and presents potential and multiple benefits for the city, and beyond. Refurbishing built environment through functional reorganizing, redesign and energy efficiency measures applications could result in prolonged longevity, architectural identity preservation and interior comfort improvement. Besides, implemented measures for energy efficiency, through the refurbishment process, should optimize the needs for energy consumption in treated buildings. This paper defines options in comfort improvements and redesign, without implying risks to the building longevity, analyses interventions and energy efficiency measures which would enable potential energy saving assessment in the refurbishment process of masonry buildings. This paper also discusses the different techniques that can be adopted for conservation and preservation of historical masonry buildings from the Austro-Hungarian period dealing with energy efficiency. The works were preceded by historical research and on-site investigations. This paper describes a methodology to quantify their vulnerability. A scheme of structural retrofitting is suggested following the research conducted. Revitalization of the building consisted in the reconstruction of the old building structure, creating the inner

  16. Energy refurbishment of the Italian residential building stock: energy and cost analysis through the application of the building typology

    International Nuclear Information System (INIS)

    Ballarini, Ilaria; Corrado, Vincenzo; Madonna, Francesco; Paduos, Simona; Ravasio, Franco

    2017-01-01

    The European residential building stock is largely composed of buildings with poor energy performance, therefore basic retrofit actions could lead to significant energy savings. However, energy refurbishment measures should be identified in accurate way, taking into account the technical viability and aiming both to increase the building energy performance and to restrain the costs. The present article investigates the effects of different measures applied to the Italian residential building stock by using the building typology, which consists of 120 building types, representative of six construction ages, four building sizes and five climatic zones. A quasi-steady state model has been used to calculate the energy performance; the economic evaluation has been carried out as specified in the EU cost-optimal comparative methodology (Directive 2010/31/EU). The most effective measures and packages of measures, in terms of energy saving and global cost reduction, are identified and discussed. The results are addressed to important purposes for energy policy, as for instance: (a) to provide political authorities with the most effective energy efficiency measures as to encourage retrofit processes through the allocation of financial incentives, (b) to offer a knowledge-base for developing energy refurbishment scenarios of residential building stocks and forecasting future energy resource demand. - Highlights: • Investigation of energy savings and cost effectiveness of the Italian housing stock refurbishments. • Application of the building typology approach of the IEE-TABULA project. • Knowledge-base for bottom-up models of the building stock energy performance. • Supporting the political authorities to promote effective refurbishment measures.

  17. Renewable-based low-temperature district heating for existing buildings in various stages of refurbishment

    DEFF Research Database (Denmark)

    Brand, Marek; Svendsen, Svend

    2013-01-01

    Denmark is aiming for a fossil-free heating sector for buildings by 2035. Judging by the national heating plan, this will be achieved mainly by a further spread of DH (district heating) based on the renewable heat sources. To make the most cost-effective use of these sources, the DH supply...... and, for 98% of the year, to below 60 °C. However for the temperatures below 60 °C a low-temperature DH substation is required for DHW (domestic hot water) heating. This research shows that renewable sources of heat can be integrated into the DH system without problems and contribute to the fossil...... temperature should be as low as possible. We used IDA–ICE software to simulate a typical Danish single-family house from the 1970s connected to DH at three different stages of envelope and space heating system refurbishment. We wanted to investigate how low the DH supply temperature can be without reducing...

  18. A containment analysis for SBLOCA without ECI in the refurbished Wolsong-1 Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T.M.; Moon, B.J.; Bae, C.J.; Lee, S.H.; Choi, C.J.; Lee, D.S. [NSSS, Korea Power Engineering Company, Inc., Daejeon (Korea, Republic of); Kim, S.M. [NETEC, Korea Hydro and Nuclear Power Company, Inc., Daejeon (Korea, Republic of)

    2010-07-01

    A small break leading to loss of coolant accident (SBLOCA), being one of the topic accidents in the nuclear plant diagnosis in recent years, has been analyzed and evaluated for the refurbished Wolsong-1 Nuclear Power Plant (NPP). The industry standard toolset (IST) codes developed by CANDU Owners Group and updated models including design change parameters are applied to the event analyses. GOTHIC code has been used for the containment analysis of Wolsong-1. Also, SMART-IST code fitted in the Iodine Chemistry (IMOD-2) model has been used to predict nuclide behavior within the containment considering various aspects. IMOD-2 was incorporated into SMART-IST as a module dealing the chemical transformations and mass transfer of iodine species in containment. IMOD-2 model is very sensitive to paint and chemicals. The parameter studies for IMOD-2 model are performed to decide the analysis value set. The developed methodology and the results of SBLOCA without ECI are presented herein. Under the most heat-up conditions, the radionuclide release from the failed fuel into the containment and subsequently to the environment is such that the radioactive doses to the public are below the acceptable limits. (author)

  19. Point Lepreau refurbishment project programmable digital comparator (PDC) replacement for SDS1 and SDS2

    International Nuclear Information System (INIS)

    Ichiyen, N.M.; Chan, D.; Thompson, P.D.

    2003-01-01

    NB Power is tentatively planning to conduct an 18-month maintenance outage of the Point Lepreau Generating Station (PLGS) starting in April 2007. The scope of the outage was determined from the outcome of a two year study (Phase 1) involving a detailed condition assessment of the station which examined issues relating to ageing and obsolescence, along with a detailed review of Safety and Licensing issues associated with extended operation. In order to minimize schedule and regulatory risk for the Refurbishment project, pre-project work was initiated in early 2002. This program is called Phase 2 ESA (Early Start Activities). As part of the Phase 1 assessments it was concluded that replacement of the PDCs (Programmable Digital Comparators) for both shutdown systems was required in order to ensure operation of the plant for a further 25-30 years. Critical tasks were identified related to PDC replacement as part of the Phase 2 ESA program. This paper describes the activities that have taken place in the Phase 2 ESA program as well as the plan for future work for the PDC replacement for SDS 1 (Shutdown System Number One) and SDS2 (Shutdown System Number Two). (author)

  20. In-Space Repair and Refurbishment of Thermal Protection System Structures for Reusable Launch Vehicles

    Science.gov (United States)

    Singh, M.

    2007-01-01

    Advanced repair and refurbishment technologies are critically needed for the thermal protection system of current space transportation systems as well as for future launch and crew return vehicles. There is a history of damage to these systems from impact during ground handling or ice during launch. In addition, there exists the potential for in-orbit damage from micrometeoroid and orbital debris impact as well as different factors (weather, launch acoustics, shearing, etc.) during launch and re-entry. The GRC developed GRABER (Glenn Refractory Adhesive for Bonding and Exterior Repair) material has shown multiuse capability for repair of small cracks and damage in reinforced carbon-carbon (RCC) material. The concept consists of preparing an adhesive paste of desired ceramic with appropriate additives and then applying the paste to the damaged/cracked area of the RCC composites with an adhesive delivery system. The adhesive paste cures at 100-120 C and transforms into a high temperature ceramic during reentry conditions. A number of plasma torch and ArcJet tests were carried out to evaluate the crack repair capability of GRABER materials for Reinforced Carbon-Carbon (RCC) composites. For the large area repair applications, Integrated Systems for Tile and Leading Edge Repair (InSTALER) have been developed and evaluated under various ArcJet testing conditions. In this presentation, performance of the repair materials as applied to RCC is discussed. Additionally, critical in-space repair needs and technical challenges are reviewed.

  1. Refurbishment of the Primary Cooling System of the Puspati Triga Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ramli, S.; Zakaria, M. F.; Masood, Z. [Malaysian Nuclear Agency, Kajang (Malaysia)

    2014-08-15

    The refurbishment of the 27 year old primary cooling system of the 1 MW PUSPATI TRIGA reactor was completed in April 2010 over an eight month outage. The project was implemented with the dual objective of meeting current user needs as well as a future reactor core power upgrade. Hence the cooling system was partly modernized to cater for a 3 MW{sub th} reactor by installing higher capacity heat exchangers and pumps while maintaining the piping and valve sizes. The old 1 MW tube and shell heat exchanger, which had lost 25% of its heat exchange capacity, was replaced with two 1.5 MW plate type heat exchangers. Several manually operated valves were replaced with motorized units to allow remote operation from the control room. The installed cooling system was flushed with distilled water and then subjected to hydrostatic pressure tests. In the cold run test, the system was operated for an hour for every pump and heat exchanger combination while all operating parameters were checked. In the hot run test, the same was done at four levels of increasing reactor power, and dose measurements were also recorded. The paper gives the design, installation, testing and commissioning details of the project. (author)

  2. Shakedown Tests for Refurbished and Upgraded Frames and Initiation of Alloy 709 Creep Rupture Tests

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moser, Jeremy L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hawkins, Charles S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lara-Curzio, Edgar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-01

    This report describes the shakedown tests conducted on the upgraded frames, and initiation of creep rupture tests on refurbished frames. SS316H, a reference material for Alloy 709, was used in shakedown tests, and the tests were conducted at 816 degree C under three stress levels to accumulate 1% creep strain. 1/4” gage diameter specimen design was used. The creep rupture tests on Alloy 709 were initiated at 600 degree C under 330 MPa to target 1,500 h rupture time. 12 specimens with 3/8” gage diameter were prepared from the materials with 6 heat treatment conditions, 2 from each. The required mechanical load under 330MPa was calculated to be 5,286 lb for the 3/8” gage diameter specimen. Among the ART frames, 7 frames are equipped with 10,000 lb load cell including #5 to 8 and #88 to 90, and can be used. 7 tests were thus started in this stage of project, and remaining 5 will be continued whenever any of the 7 tests is completed.

  3. Energy Refurbishment of an Office Building with Hybrid Photovoltaic System and Demand-Side Management

    Directory of Open Access Journals (Sweden)

    Giovani Almeida Dávi

    2017-08-01

    Full Text Available On-site photovoltaic (PV and battery systems intend to improve buildings energy performance, however battery costs and monetary incentives are a major drawback for the introduction of these technologies into the electricity grids. This paper proposes an energy refurbishment of an office building based on multi-objective simulations. An innovative demand-side management approach is analyzed through the PV and battery control with the purpose of reducing grid power peaks and grid imported energy, as well as improving the project economy. Optimization results of load matching and grid interaction parameters, complemented with an economic analysis, are investigated in different scenarios. By means of battery use, the equivalent use of the grid connection is reduced by 12%, enhancing the grid interaction potential, and 10% of load matching rates can be increased. Project improvements indicate the grid connection capacity can be reduced by 13% and significant savings of up to 48% are achieved on yearly bills. The economy demonstrates the grid parity is only achieved for battery costs below 100 €/kWh and the payback period is large: 28 years. In the case with only PV system, the grid parity achieves better outcomes and the payback time is reduced by a half, making this a more attractive option.

  4. In search of a holistic, sustainable and replicable model for complete energy refurbishment in historic buildings

    Directory of Open Access Journals (Sweden)

    Marija S. Todorović

    2012-12-01

    Full Text Available The reduction of greenhouse gas emissions in buildings offers one of the most promising opportunities for developed and developing countries to cooperate in achieving the realization of significant energy efficiency improvements. However, achieving sustainability is not an easy task unless there is synergy with/between energy efficiency improvement and renewable energy sources (RES - these are not at present in widespread dissemination and use. This paper recognizes the synergetic relationship between conservation and sustainability. At present, the role of heritage conservation in achieving sustainability has not yet been fully recognized, nor have heritage needs been well integrated into sustainability initiatives. Historic buildings are inherently sustainable. Preservation maximizes the use of existing materials and infrastructures, reduces waste, and preserves the historical character of older towns and cities. Sustainability begins with preservation. Taking into account the original climatic adaptations of historic buildings, today’s sustainable technology can supplement inherent sustainable features without compromising their unique historical character. Furthermore, a number of paper reviews and case studies with related methodologies outline the need to implement the latest current knowledge and technologies (BPS - Building Performance Simulation and CFD - Computational Fluid Dynamics for use in the refurbishment design process, as well as highlighting the crucial importance of sustainability, relevant benchmarking and rating system development.

  5. A comparative study of the corrosion resistance of incoloy MA 956 and PM 2000 superalloys

    Directory of Open Access Journals (Sweden)

    Maysa Terada

    2010-12-01

    Full Text Available Austenitic stainless steels, titanium and cobalt alloys are widely used as biomaterials. However, new medical devices require innovative materials with specific properties, depending on their application. The magnetic properties are among the properties of interest for some biomedical applications. However, due to the interaction of magnetic materials with Magnetic Resonance Image equipments they might used only as not fixed implants or for medical devices. The ferromagnetic superalloys, Incoloy MA 956 and PM 2000, produced by mechanical alloying, have similar chemical composition, high corrosion resistance and are used in high temperature applications. In this study, the corrosion resistance of these two ferritic superalloys was compared in a phosphate buffer solution. The electrochemical results showed that both superalloys are passive in this solution and the PM 2000 present a more protective passive film on it associated to higher impedances than the MA 956.

  6. A new method in prediction of TCP phases formation in superalloys

    International Nuclear Information System (INIS)

    Mousavi Anijdan, S.H.; Bahrami, A.

    2005-01-01

    The purpose of this investigation is to develop a model for prediction of topologically closed-packed (TCP) phases formation in superalloys. In this study, artificial neural networks (ANN), using several different network architectures, were used to investigate the complex relationships between TCP phases and chemical composition of superalloys. In order to develop an optimum ANN structure, more than 200 experimental data were used to train and test the neural network. The results of this investigation shows that a multilayer perceptron (MLP) form of the neural networks with one hidden layer and 10 nodes in the hidden layer has the lowest mean absolute error (MAE) and can be accurately used to predict the electron-hole number (N v ) and TCP phases formation in superalloys

  7. Degradation of creep properties in a long-term thermally exposed nickel base superalloy

    International Nuclear Information System (INIS)

    Zrnik, J.; Strunz, P.; Vrchovinsky, V.; Muransky, O.; Novy, Z.; Wiedenmann, A.

    2004-01-01

    When exposed for long time at elevated temperatures of 430 and 650 deg. C the nickel base superalloy EI 698 VD can experience a significant decrease in creep resistance. The cause of the creep degradation of nickel base superalloy is generally attributed to the microstructural instability at prolonged high temperature exposure. In this article, the creep-life data, generated on long thermally exposed nickel base superalloy EI698 VD were related to the local microstructural changes observed using SEM and TEM analysing techniques. While structure analysis provided supporting evidence concerning the changes associated with grain boundary carbide precipitation, no persuasive evidence of a morphological and/or dimensional gamma prime change was showed. For clarifying of the role of gamma prime precipitates on alloy on creep degradation, the SANS (small angle neutron scattering) experiment was crucial in the characterization of the bulk-averaged gamma prime morphology and its size distribution with respect to the period of thermal exposure

  8. Zinc-induced embrittlement in nickel-base superalloys by simulation and experiment

    Science.gov (United States)

    Otis, Richard; Waje, Mahesh; Lindwall, Greta; Jefferson, Tiffany; Lange, Jeremy; Liu, Zi-Kui

    2017-09-01

    The high cost of Re has driven interest in processes for recovering Re from scrap superalloy parts. In this work thermodynamic modelling is used to study Zn-induced embrittlement of a superalloy and to direct experiments. Treating superalloy powder with Zn vapour reduces the average particle size after milling from approximately ?m to 0.5-10 ?m, vs. ?m for untreated powder. Simulations predict the required treatment time to increase with temperature. Agreement between predictions and experiments suggests that an embrittling liquid forms in less than an hour of Zn vapour treatment between 950-1000 ?C and partial pressures of Zn between 14-34 kPa (2-5 psi).

  9. Alloying effects of refractory elements in the dislocation of Ni-based single crystal superalloys

    Directory of Open Access Journals (Sweden)

    Shiyu Ma

    2016-12-01

    Full Text Available The alloying effects of W, Cr and Re in the [100] (010 edge dislocation cores (EDC of Ni-based single crystal superalloys are investigated using first-principles based on the density functional theory (DFT. The binding energy, Mulliken orbital population, density of states, charge density and radial distribution functions are discussed, respectively. It is clearly demonstrated that the addition of refractory elements improves the stability of the EDC systems. In addition, they can form tougher bonds with their nearest neighbour (NN Ni atoms, which enhance the mechanical properties of the Ni-based single crystal superalloys. Through comparative analysis, Cr-doped system has lower binding energy, and Cr atom has evident effect to improve the systemic stability. However, Re atom has the stronger alloying effect in Ni-based single crystal superalloys, much more effectively hindering dislocation motion than W and Cr atoms.

  10. A Review on Inertia and Linear Friction Welding of Ni-Based Superalloys

    Science.gov (United States)

    Chamanfar, Ahmad; Jahazi, Mohammad; Cormier, Jonathan

    2015-04-01

    Inertia and linear friction welding are being increasingly used for near-net-shape manufacturing of high-value materials in aerospace and power generation gas turbines because of providing a better quality joint and offering many advantages over conventional fusion welding and mechanical joining techniques. In this paper, the published works up-to-date on inertia and linear friction welding of Ni-based superalloys are reviewed with the objective to make clarifications on discrepancies and uncertainties reported in literature regarding issues related to these two friction welding processes as well as microstructure, texture, and mechanical properties of the Ni-based superalloy weldments. Initially, the chemical composition and microstructure of Ni-based superalloys that contribute to the quality of the joint are reviewed briefly. Then, problems related to fusion welding of these alloys are addressed with due consideration of inertia and linear friction welding as alternative techniques. The fundamentals of inertia and linear friction welding processes are analyzed next with emphasis on the bonding mechanisms and evolution of temperature and strain rate across the weld interface. Microstructural features, texture development, residual stresses, and mechanical properties of similar and dissimilar polycrystalline and single crystal Ni-based superalloy weldments are discussed next. Then, application of inertia and linear friction welding for joining Ni-based superalloys and related advantages over fusion welding, mechanical joining, and machining are explained briefly. Finally, present scientific and technological challenges facing inertia and linear friction welding of Ni-based superalloys including those related to modeling of these processes are addressed.

  11. Crack initiation modeling of a directionally-solidified nickel-base superalloy

    Science.gov (United States)

    Gordon, Ali Page

    Combustion gas turbine components designed for application in electric power generation equipment are subject to periodic replacement as a result of cracking, damage, and mechanical property degeneration that render them unsafe for continued operation. In view of the significant costs associated with inspecting, servicing, and replacing damaged components, there has been much interest in developing models that not only predict service life, but also estimate the evolved microstructural state of the material. This thesis explains manifestations of microstructural damage mechanisms that facilitate fatigue crack nucleation in a newly-developed directionally-solidified (DS) Ni-base superalloy components exposed to elevated temperatures and high stresses. In this study, models were developed and validated for damage and life prediction using DS GTD-111 as the subject material. This material, proprietary to General Electric Energy, has a chemical composition and grain structure designed to withstand creep damage occurring in the first and second stage blades of gas-powered turbines. The service conditions in these components, which generally exceed 600°C, facilitate the onset of one or more damage mechanisms related to fatigue, creep, or environment. The study was divided into an empirical phase, which consisted of experimentally simulating service conditions in fatigue specimens, and a modeling phase, which entailed numerically simulating the stress-strain response of the material. Experiments have been carried out to simulate a variety of thermal, mechanical, and environmental operating conditions endured by longitudinally (L) and transversely (T) oriented DS GTD-111. Both in-phase and out-of-phase thermo-mechanical fatigue tests were conducted. In some cases, tests in extreme environments/temperatures were needed to isolate one or at most two of the mechanisms causing damage. Microstructural examinations were carried out via SEM and optical microscopy. A continuum

  12. Corrosion Behavior of Superalloys in Hot Lithium Molten Salt

    International Nuclear Information System (INIS)

    Cho, Soo-Haeng; Hur, Jin-Mok; Seo, Chung-Seok; Park, Seoung-Won

    2006-01-01

    The Li-reduction process involves the chemical reduction of spent fuel oxides by liquid lithium metal in a molten LiCl salt bath at 650 .deg. C followed by a separate electrochemical reduction of lithium oxide (Li 2 O), which builds up in the salt bath. This process requires a high purity inert gas atmosphere inside remote hot cell nuclear facility to prevent unwanted Li oxidation and fires during the handling of chemically active Li metal. In light of the limitations of the Li-reduction process, a direct electrolytic reduction technology is being developed by KAERI to enhance process safety and economic viability. The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. Even so, the electrochemical process vessel must be resilient at ∼ 650 .deg. C in the presence of oxygen to enable high processing rates and an extended service life. But, the mechanism and the rate of the corrosion of metals in LiCl-Li 2 O molten salt under oxidation condition are not clear. In the present work, the corrosion behavior and corrosion mechanism of superalloys have been studied in the molten salt of LiCl-Li 2 O under oxidation condition

  13. Structural Performance of Inconel 625 Superalloy Brazed Joints

    Science.gov (United States)

    Chen, Jianqiang; Demers, Vincent; Cadotte, Eve-Line; Turner, Daniel; Bocher, Philippe

    2017-02-01

    The purpose of this work was to investigate tensile and fatigue behaviors of Inconel 625 superalloy brazed joints after transient liquid-phase bonding process. Brazing was performed in a vacuum furnace using a nickel-based filler metal in a form of paste to join wrought Inconel 625 plates. Mechanical tests were carried out on single-lap joints under various lap distance-to-thickness ratios. The fatigue crack initiation and crack growth modes were examined via metallographic analysis, and the effect of local stress on fatigue life was assessed by finite element simulations. The fatigue results show that fatigue strength and endurance limit increase with overlap distance, leading to a relatively large scatter of results. Fatigue cracks nucleated in the high-stressed region of the weld fillets from brittle eutectic phases or from internal brazing cavities. The present work proposes to rationalize the results by using the local stress at the brazing fillet. When using this local stress, all fatigue-obtained results find themselves on a single S- N curve, providing a design curve for any joint configuration in fatigue solicitation.

  14. Kinetics of Grain Growth in 718 Ni-Base Superalloy

    Directory of Open Access Journals (Sweden)

    Huda Z.

    2014-10-01

    Full Text Available The Haynes® 718 Ni-base superalloy has been investigated by use of modern material characterization, metallographic and heat treatment equipment. Grain growth annealing experiments at temperatures in the range of 1050 – 1200 oC (1323–1473K for time durations in the range of 20 min-22h have been conducted. The kinetic equations and an Arrhenius-type equation have been applied to compute the grain-growth exponent n and the activation energy for grain growth, Qg, for the investigated alloy. The grain growth exponent, n, was computed to be in the range of 0.066-0.206; and the n values have been critically discussed in relation to the literature. The activation energy for grain growth, Qg, for the investigated alloy has been computed to be around 440 kJ/mol; and the Qg data for the investigated alloy has been compared with other metals and alloys and ceramics; and critically analyzed in relation to our results.

  15. The precipitation behavior of superalloy ATI Allvac 718Plus

    Energy Technology Data Exchange (ETDEWEB)

    Zickler, Gerald A.; Schnitzer, Ronald; Leitner, Harald [Department of Physical Metallurgy and Materials Testing, Christian Doppler Laboratory Early Stages of Precipitation, Montanuniversitaet Leoben (Austria); Radis, Rene [Christian Doppler Laboratory Early Stages of Precipitation, Institute of Materials Science and Technology, Vienna University of Technology (Austria); Institute for Materials Science and Welding, Graz University of Technology (Austria); Kozeschnik, Ernst [Christian Doppler Laboratory Early Stages of Precipitation, Institute of Materials Science and Technology, Vienna University of Technology (Austria); Stockinger, Martin [Boehler Schmiedetechnik GmbH and Co. KG., Kapfenberg (Austria)

    2010-03-15

    ATI Allvac 718Plus is a novel nickel-based superalloy, which was designed for heavy-duty applications in aerospace gas turbines. The precipitation kinetics of the intermetallic {delta} (Ni{sub 3}Nb) and {gamma}' (Ni{sub 3}(Al,Ti)) phases in this alloy are of scientific as well as technological interest because of their significant influence on the mechanical properties. Important parameters like grain size are controlled by coarse {delta} precipitates located at grain boundaries, whereas small {gamma}' precipitates are responsible for strengthening by precipitation hardening. In the present study, the microstructure is investigated by three-dimensional atom probe tomography and simulated by computer modeling using the thermo-kinetic software MatCalc. The results of numerical simulations and experimental data are compared and critically discussed. It is shown that the chemical compositions of the phases change during isothermal aging, and the precipitation kinetics of {delta} and {gamma}' phases interact with each other as shown in a time temperature precipitation (TTP) plot. The TTP plot shows C-shaped curves with characteristic discontinuities in the temperature range, where simultaneous and concurrent precipitation of the {delta} and {gamma}' phases occurs. This leads to a competition in the diffusion of Nb and Al, which are partly present in both phases. Thus, the present study gives important information on heat treatments for ATI Allvac 718Plus in order to achieve the desired microstructure and mechanical properties. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  16. Niobium-base superalloys via powder metallurgy technology

    International Nuclear Information System (INIS)

    Loria, E.A.

    1987-01-01

    This paper provides some insight into an area that has been neglected, namely the possibility of developing high-strength, niobium-base alloys by improved oxidation resistance via the consolidation of rapidly solidified powders. Powder metallurgy (P/M) is an attractive processing technique because of its flexibility and versatility, and it may provide the alloys with properties and workability not obtainable via metal casting. A critical review of both U.S. and Russian literature is presented along with suggestions on the most promising compositions and processing techniques available to meet these competing goals. Previous work on many niobium alloys reveals that long term properties are retained well above those obtained on nickel-base superalloys. Cast and wrought alloys extend specific strength beyond 1200 0 C (2200 0 F), but lack oxidation resistance. Remarkable oxidation resistance is obtained, however, on miniature castings of certain ternary alloys which are too brittle for any processing. A better understanding of the oxidation mechanism is necessary before the proper P/M (RST) approach is taken on compositions which could provide compatibility between the two competing goals through grain refinement and a homogeneous distribution of the contributory phases. Finally, ways to up-scale production of Nb powder are discussed, including thermodynamic feasibility for the direct reduction of NbCl/sub 5/ in a 1.5 MW plasma reactor

  17. Friction Freeform Fabrication of Superalloy Inconel 718: Prospects and Problems

    Science.gov (United States)

    Dilip, J. J. S.; Janaki Ram, G. D.

    2014-01-01

    Friction Freeform Fabrication is a new solid-state additive manufacturing process. The present investigation reports a detailed study on the prospects of this process for additive part fabrication in superalloy Inconel 718. Using a rotary friction welding machine and employing alloy 718 consumable rods in solution treated condition, cylindrical-shaped multi-layer friction deposits (10 mm diameter) were successfully produced. In the as-deposited condition, the deposits showed very fine grain size with no grain boundary δ phase. The deposits responded well to direct aging and showed satisfactory room-temperature tensile properties. However, their stress rupture performance was unsatisfactory because of their layered microstructure with very fine grain size and no grain boundary δ phase. The problem was overcome by heat treating the deposits first at 1353 K (1080 °C) (for increasing the grain size) and then at 1223 K (950 °C) (for precipitating the δ phase). Overall, the current study shows that Friction Freeform Fabrication is a very useful process for additive part fabrication in alloy 718.

  18. Microstructural characteristics of high-temperature oxidation in nickel-base superalloy

    International Nuclear Information System (INIS)

    Khalid, F.A.

    1997-01-01

    Superalloys are used for aerospace and nuclear applications where they can withstand high-temperature and severe oxidizing conditions. High-temperature oxidation behavior of a nickel-base superalloy is examined using optical and scanning electron microscopical techniques. The morphology of the oxide layers developed is examined, and EDX microanalysis reveals diffusion of the elements across the oxide-metal interface. Evidence of internal oxidation is presented, and the role of structural defects is considered. The morphology of the oxide-metal interface formed in the specimens exposed in steam and air is examined to elucidate the mechanism of high-temperature oxidation

  19. Mechanical Behavior of Three-Dimensional Braided Nickel-Based Superalloys Synthesized via Pack Cementation

    Science.gov (United States)

    Lippitz, Nicolas; Erdeniz, Dinc; Sharp, Keith W.; Dunand, David C.

    2018-03-01

    Braided tubes of Ni-based superalloys are fabricated via three-dimensional (3-D) braiding of ductile Ni-20Cr (wt pct) wires followed by post-textile gas-phase alloying with Al and Ti to create, after homogenization and aging, γ/ γ' strengthened lightweight, porous structures. Tensile tests reveal an increase in strength by 100 MPa compared to as-braided Ni-20Cr (wt pct). An interrupted tensile test, combined with X-ray tomographic scans between each step, sheds light on the failure behavior of the braided superalloy tubes.

  20. Process of welding gamma prime-strengthened nickel-base superalloys

    Science.gov (United States)

    Speigel, Lyle B.; White, Raymond Alan; Murphy, John Thomas; Nowak, Daniel Anthony

    2003-11-25

    A process for welding superalloys, and particularly articles formed of gamma prime-strengthened nickel-base superalloys whose chemistries and/or microstructures differ. The process entails forming the faying surface of at least one of the articles to have a cladding layer of a filler material. The filler material may have a composition that is different from both of the articles, or the same as one of the articles. The cladding layer is machined to promote mating of the faying surfaces, after which the faying surfaces are mated and the articles welded together. After cooling, the welded assembly is free of thermally-induced cracks.

  1. Energy analysis and refurbishment proposals for public housing in the city of Bari, Italy

    International Nuclear Information System (INIS)

    Di Turi, Silvia; Stefanizzi, Pietro

    2015-01-01

    From the perspectives of the energy and the environment, building stock should be considered a useful resource in the struggle against greenhouse gas emissions and scarcity of energy resources. The aim of this work is to provide an example of the application of a methodology to evaluate the energy needs of the building stock of a city and to determine the possible strategies for energy planning. This paper aims to obtain an estimate, on an urban scale, of the energy needs and CO 2 emissions of the public residential buildings of Bari. This estimate is achieved by evaluating the critical issues of the built heritage, the most common architectural typologies and the heating systems in the territory of the city of Bari in southern Italy, as well as the possible strategies for upgrading energy efficiency, through the combined use of energy software and geo-referenced systems. Furthermore, several possible interventions are assumed to improve the energy performance of buildings in not only environmental terms but also economic terms through the instrument of cost–benefit analysis. The ultimate goal is to compare the different intervention strategies to determine which demonstrate greater cost effectiveness and feasibility for future energy planning. - Highlights: • An evaluation of the energy needs of existing buildings in a city in Southern Italy is provided. • Possible refurbishment strategies are evaluated. • An economic analysis is carried out to understand the feasibility of interventions. • An estimate on an urban scale of the energy-saving potential of public housing in Bari is provided

  2. Refurbishment priorities at the Russian coal-fired power sector for cleaner energy production case studies

    Energy Technology Data Exchange (ETDEWEB)

    P. Grammelis; N. Koukouzas; G. Skodras; E. Kakaras; A. Tumanovsky; V. Kotler [Centre for Research and Technology Hellas/Institute of Solid Fuels Technology and Applications (CERTH/ISFTA), Ptolemaida (Greece)

    2006-11-15

    The paper reviews the current status of the coal-fired power sector in Russia, the prospects for renovation activities based on Clean Coal Technologies (CCT) and presents two case studies on potential refurbishment projects. Data were collected for 180 thermoelectric units with capacity higher than 100 MWe and the renovation needs of the power sector, among the retrofitting, repowering and reconstruction options, were estimated through a multi-criteria analysis. The most attractive system to renovate a power plant between the Supercritical Combustion (SC) and the Fluidized Bed Combustion (FBC) technologies was evaluated. The application of each of the aforementioned technologies at the Kashirskaya and Shaturskaya power plants was studied and their replication potential in the Russian coal-fired power plant park was examined. Nowadays, the installed capacity of coal-fired power plants in the Russian Federation is 29.3 GWe, while they account for about 19% of the total electricity generation in the area. The low efficiency and especially the advanced age are the determinant factors for renovation applications at the Russian units. Even in the more conservative modernization scenario, over 30% of the thermoelectric units have to be repowered or reconstructed. Concrete proposals about the profitable and reliable operation of two Russian thermoelectric units with minimized environmental effects were elaborated. A new unit of 315 MWe with supercritical steam parameters and reburning for NOx abatement is envisaged to upgrade Unit 1 of Kashirskaya power station, while new circulating fluidized bed (CFB) boilers of the same steam generation is the most promising renovation option for the boilers of Unit 1 in Shaturskaya power station. 11 refs., 15 figs., 7 tabs.

  3. Design of a braze alloy for fast epitaxial brazing of superalloys

    Science.gov (United States)

    Piegert, S.; Laux, B.; Rösier, J.

    2012-07-01

    For the repair of directionally solidified turbine components made of nickel-based superalloys, a new high-temperature brazing method has been developed. Utilising heterogeneous nucleation on the crack surface, the microstructure of the base material can be reproduced, i.e. single crystallinity can be maintained. In contrast to commonly used eutectic braze alloys, such as nickel-boron or nickel-silicon systems, the process is not diffusion controlled but works with a consolute binary base system. The currently applied epitaxial brazing methods rely on isothermal solidification diffusing the melting point depressants into the base material until their concentration is reduced so that the liquid braze solidifies. Contrary, the identified Ni-Mn consolute system enables a temperature driven epitaxial solidification resulting in substantially reduced process duration. The development of the braze alloys was assisted using the CALPHAD software Thermo-Calc. The solidification behaviour was estimated by kinetic calculations with realistic boundary conditions. Finally, the complete system, including braze alloy as well as substrate material, was modelled by means of DICTRA. Subsequently, the thermodynamic properties of the braze alloys were experimentally analysed by DSC measurements. For brazing experiments 300 μm wide parallel gaps were used. Complete epitaxial solidification, i.e. the absence of high-angle grain boundaries, could be achieved within brazing times being up to two orders of magnitude shorter compared to diffusion brazing processes. Theoretically and experimentally evaluated process windows reveal similar shapes. However, a distinct shift has to be stated which can be ascribed to the limited accuracy of the underlying thermodynamic databases.

  4. Identifying and Understanding Environment-Induced Crack propagation Behavior in Ni-based Superalloy INCONEL 617

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Longzhou

    2012-11-30

    The nickel-based superalloy INCONEL 617 is a candidate material for heat exchanger applications in the next-generation nuclear plant (NGNP) system. This project will study the crack propagation process of alloy 617 at temperatures of 650°C-950°C in air under static/cyclic loading conditions. The goal is to identify the environmental and mechanical damage components and to understand in-depth the failure mechanism. Researchers will measure the fatigue crack propagation (FCP) rate (da/dn) under cyclic and hold-time fatigue conditions, and sustained crack growth rates (da/dt) at elevated temperatures. The independent FCP process will be identified and the rate-controlled sustained loading crack process will be correlated with the thermal activation equation to estimate the oxygen thermal activation energy. The FCP-dependent model indicates that if the sustained loading crack growth rate, da/dt, can be correlated with the FCP rate, da/dn, at the full time dependent stage, researchers can confirm stress-accelerated grain-boundary oxygen embrittlement (SAGBOE) as a predominate effect. Following the crack propagation tests, the research team will examine the fracture surface of materials in various cracking stages using a scanning electron microscope (SEM) and an optical microscope. In particular, the microstructure of the crack tip region will be analyzed in depth using high resolution transmission electron microscopy (TEM) and electron energy loss spectrum (EELS) mapping techniques to identify oxygen penetration along the grain boundary and to examine the diffused oxygen distribution profile around the crack tip. The cracked sample will be prepared by focused ion beam nanofabrication technology, allowing researchers to accurately fabricate the TEM samples from the crack tip while minimizing artifacts. Researchers will use these microscopic and spectroscopic results to interpret the crack propagation process, as well as distinguish and understand the environment or

  5. Effect of carbon additions on the as-cast microstructure and defect formation of a single crystal Ni-based superalloy

    International Nuclear Information System (INIS)

    Al-Jarba, K.A.; Fuchs, G.E.

    2004-01-01

    In an effort to reduce grain defects in large single crystal Ni-base superalloy components, carbon is intentionally added. In this study, the effect of carbon additions on the microstructure and solidification defect formation of a model Ni-based superalloy, LMSX-1, was examined. The results show that the tendency of the alloy to form all types of solidification defects decreased as the carbon content increased. The as-cast microstructures also exhibited a decrease in the amount of γ-γ' eutectic structure and an increase in the volume fraction of carbides and porosity, as the carbon content was increased. The carbides formed in these alloys were mostly of script-type MC carbides which formed continuous, dendritic networks in the interdendritic region. Microprobe analysis of the as-cast structures showed that the partitioning coefficients did not change with carbon additions. Therefore, the reduction in defect formation with increasing carbon content could not be attributed to changes in segregation behavior of alloying elements. Instead, the presence of these carbides in the interdendritic regions of the alloy appeared to have prevented the thermosolutal fluid flow

  6. Multi-Scale Computational Modeling of Ni-Base Superalloy Brazed Joints for Gas Turbine Applications

    Science.gov (United States)

    Riggs, Bryan

    Brazed joints are commonly used in the manufacture and repair of aerospace components including high temperature gas turbine components made of Ni-base superalloys. For such critical applications, it is becoming increasingly important to account for the mechanical strength and reliability of the brazed joint. However, material properties of brazed joints are not readily available and methods for evaluating joint strength such as those listed in AWS C3.2 have inherent challenges compared with testing bulk materials. In addition, joint strength can be strongly influenced by the degree of interaction between the filler metal (FM) and the base metal (BM), the joint design, and presence of flaws or defects. As a result, there is interest in the development of a multi-scale computational model to predict the overall mechanical behavior and fitness-for-service of brazed joints. Therefore, the aim of this investigation was to generate data and methodology to support such a model for Ni-base superalloy brazed joints with conventional Ni-Cr-B based FMs. Based on a review of the technical literature a multi-scale modeling approach was proposed to predict the overall performance of brazed joints by relating mechanical properties to the brazed joint microstructure. This approach incorporates metallurgical characterization, thermodynamic/kinetic simulations, mechanical testing, fracture mechanics and finite element analysis (FEA) modeling to estimate joint properties based on the initial BM/FM composition and brazing process parameters. Experimental work was carried out in each of these areas to validate the multi-scale approach and develop improved techniques for quantifying brazed joint properties. Two Ni-base superalloys often used in gas turbine applications, Inconel 718 and CMSX-4, were selected for study and vacuum furnace brazed using two common FMs, BNi-2 and BNi-9. Metallurgical characterization of these brazed joints showed two primary microstructural regions; a soft

  7. High-temperature and low-stress creep anisotropy of single-crystal superalloys

    Czech Academy of Sciences Publication Activity Database

    Jacome, L. A.; Nortershauser, P.; Heyer, J. K.; Lahni, A.; Frenzel, J.; Dlouhý, Antonín; Somsen, C.; Eggeler, G.

    2013-01-01

    Roč. 61, č. 8 (2013), s. 2926-2943 ISSN 1359-6454 R&D Projects: GA ČR(CZ) GA202/09/2073 Institutional support: RVO:68081723 Keywords : superalloy single crystals * creep anisotropy * rafting * dislocations * deformation mechanisms Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.940, year: 2013

  8. σ and η Phase formation in advanced polycrystalline Ni-base superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Antonov, Stoichko, E-mail: santonov@hawk.iit.edu [Illinois Institute of Technology, 10 W. 32nd Street, Chicago, IL 60616 (United States); Huo, Jiajie; Feng, Qiang [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Isheim, Dieter; Seidman, David N. [Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208 (United States); Northwestern University Center for Atom Probe Tomography (NUCAPT), 2220 Campus Drive, Evanston, IL 60208 (United States); Helmink, Randolph C.; Sun, Eugene [Rolls-Royce Corporation, 450 S. Meridian Street, Indianapolis, IN 46225 (United States); Tin, Sammy [Illinois Institute of Technology, 10 W. 32nd Street, Chicago, IL 60616 (United States)

    2017-02-27

    In polycrystalline Ni-base superalloys, grain boundary precipitation of secondary phases can be significant due to the effects they pose on the mechanical properties. As new alloying concepts for polycrystalline Ni-base superalloys are being developed to extend their temperature capability, the effect of increasing levels of Nb alloying additions on long term phase stability and the formation of topologically close packed (TCP) phases needs to be studied. Elevated levels of Nb can result in increased matrix supersaturation and promote the precipitation of secondary phases. Long term thermal exposures on two experimental powder processed Ni-base superalloys containing various levels of Nb were completed to assess the stability and precipitation of TCP phases. It was found that additions of Nb promoted the precipitation of η-Ni{sub 6}AlNb along the grain boundaries in powder processed, polycrystalline Ni-base superalloys, while reduced Nb levels favored the precipitation of blocky Cr and Mo – rich σ phase precipitates along the grain boundary. Evaluation of the thermodynamic stability of these two phases in both alloys using Thermo-calc showed that while σ phase predictions are fairly accurate, predictions of the η phase are limited.

  9. Creep deformation and microstructural examination of a prior thermally exposed nickel base superalloy

    Czech Academy of Sciences Publication Activity Database

    Zrník, J.; Strunz, Pavel; Vrchovinský, V.; Muránsky, O.; Horňák, P.; Wiedenmann, A.

    2004-01-01

    Roč. 274 (2004), s. 925-930 ISSN 1013-9826 R&D Projects: GA AV ČR KSK1010104 Keywords : superalloy * thermal exposition * creep Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.278, year: 2004

  10. SANS investigation of precipitate microstructure in nickel-base superalloys Waspaloy and DT750

    Czech Academy of Sciences Publication Activity Database

    Strunz, Pavel; Zrník, J.; Seliga, T.; Penkalla, H.J.

    2006-01-01

    Roč. 2, č. 23 (2006), s. 363-368 ISSN 0044-2968 R&D Projects: GA ČR GA202/06/0601 Institutional research plan: CEZ:AV0Z10480505 Keywords : small-angle-neutron scattering * superalloys * precipitation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.897, year: 2006

  11. Ledges and grooves at γ/γ′ interfaces of single crystal superalloys

    Czech Academy of Sciences Publication Activity Database

    Parsa, A. B.; Wollgramm, P.; Buck, H.; Kostka, A.; Somsen, C.; Dlouhý, Antonín; Eggeler, G.

    2015-01-01

    Roč. 90, MAY (2015), s. 105-117 ISSN 1359-6454 R&D Projects: GA ČR(CZ) GA14-22834S Institutional support: RVO:68081723 Keywords : Ni-base single crystal superalloys * γ/γ′ interfaces * Interface dislocations * Rafting * Grooves Subject RIV: JG - Metallurgy Impact factor: 5.058, year: 2015

  12. Fundamental studies of electron beam welding of heat-resistant superalloys for nuclear plants, 5

    International Nuclear Information System (INIS)

    Arata, Yoshiaki; Terai, Kiyohide; Nagai, Hiroyoshi; Shimizu, Shigeki; Aota, Toshiichi.

    1978-01-01

    In this paper, the mechanical properties of base metal, its electron beam and TIG weld joint of superalloys for nuclear plants were made clear and compared with each other. As a result, it has been clarified that electron beam weld joint is superior to TIG weld joint and nearly comparable to base metal. (author)

  13. Microstructural study of weld fusion zone of TIG welded IN 738LC nickel-based superalloy

    International Nuclear Information System (INIS)

    Ojo, O.A.; Richards, N.L.; Chaturvedi, M.C.

    2004-01-01

    The weld fusion zone microstructure of a commercial aerospace superalloy IN 738 was examined. Elemental segregation induced interdendritic microconstituents were identified to include terminal solidification product M 3 B 2 and Ni 7 Zr 2 in association with γ-γ' eutectic constituent, which require proper consideration during the development of optimum post weld heat treatment

  14. High temperature oxidation characteristics of developed Ni-Cr-W superalloys in air

    International Nuclear Information System (INIS)

    Suzuki, Tomio; Shindo, Masami

    1996-11-01

    For expanding utilization of the Ni-Cr-W superalloy, which has been developed as one of new high temperature structural materials used in the advanced High Temperature Gas-cooled Reactors (HTGRs), in various engineering fields including the structural material for heat utilization system, the oxidation behavior of this alloy in air as one of high oxidizing environments becomes one of key factors. The oxidation tests for the industrial scale heat of Ni-Cr-W superalloy with the optimized chemical composition and five kinds of experimental Ni-Cr-W alloys with different Cr/W ratio were carried out at high temperatures in the air compared with Hastelloy XR. The conclusions were obtained as follows. (1) The oxidation resistance of the industrial scale heat of Ni-Cr-W superalloy with the optimized chemical composition was superior to that of Hastelloy XR. (2) The most excellent oxidation resistance was obtained in an alloy with 19% Cr of the industrial scale heat of Ni-Cr-W superalloy. (author)

  15. MC Carbide Characterization in High Refractory Content Powder-Processed Ni-Based Superalloys

    Science.gov (United States)

    Antonov, Stoichko; Chen, Wei; Huo, Jiajie; Feng, Qiang; Isheim, Dieter; Seidman, David N.; Sun, Eugene; Tin, Sammy

    2018-04-01

    Carbide precipitates in Ni-based superalloys are considered to be desirable phases that can contribute to improving high-temperature properties as well as aid in microstructural refinement of the material; however, they can also serve as crack initiation sites during fatigue. To date, most of the knowledge pertaining to carbide formation has originated from assessments of cast and wrought Ni-based superalloys. As powder-processed Ni-based superalloys are becoming increasingly widespread, understanding the different mechanisms by which they form becomes increasingly important. Detailed characterization of MC carbides present in two experimental high Nb-content powder-processed Ni-based superalloys revealed that Hf additions affect the resultant carbide morphologies. This morphology difference was attributed to a higher magnitude of elastic strain energy along the interface associated with Hf being soluble in the MC carbide lattice. The composition of the MC carbides was studied through atom probe tomography and consisted of a complex carbonitride core, which was rich in Nb and with slight Hf segregation, surrounded by an Nb carbide shell. The characterization results of the segregation behavior of Hf in the MC carbides and the subsequent influence on their morphology were compared to density functional theory calculations and found to be in good agreement, suggesting that computational modeling can successfully be used to tailor carbide features.

  16. Freckle Defect Formation near the Casting Interfaces of Directionally Solidified Superalloys.

    Science.gov (United States)

    Hong, Jianping; Ma, Dexin; Wang, Jun; Wang, Fu; Sun, Baode; Dong, Anping; Li, Fei; Bührig-Polaczek, Andreas

    2016-11-16

    Freckle defects usually appear on the surface of castings and industrial ingots during the directional solidification process and most of them are located near the interface between the shell mold and superalloys. Ceramic cores create more interfaces in the directionally solidified (DS) and single crystal (SX) hollow turbine blades. In order to investigate the location of freckle occurrence in superalloys, superalloy CM247 LC was directionally solidified in an industrial-sized Bridgman furnace. Instead of ceramic cores, Alumina tubes were used inside of the casting specimens. It was found that freckles occur not only on the casting external surfaces, but also appear near the internal interfaces between the ceramic core and superalloys. Meanwhile, the size, initial position, and area of freckle were investigated in various diameters of the specimens. The initial position of the freckle chain reduces when the diameter of the rods increase. Freckle area follows a linear relationship in various diameters and the average freckle fraction is 1.1% of cross sectional area of casting specimens. The flow of liquid metal near the interfaces was stronger than that in the interdendritic region in the mushy zone, and explained why freckle tends to occur on the outer or inner surfaces of castings. This new phenomenon suggests that freckles are more likely to occur on the outer or inner surfaces of the hollow turbine blades.

  17. Freckle Defect Formation near the Casting Interfaces of Directionally Solidified Superalloys

    Directory of Open Access Journals (Sweden)

    Jianping Hong

    2016-11-01

    Full Text Available Freckle defects usually appear on the surface of castings and industrial ingots during the directional solidification process and most of them are located near the interface between the shell mold and superalloys. Ceramic cores create more interfaces in the directionally solidified (DS and single crystal (SX hollow turbine blades. In order to investigate the location of freckle occurrence in superalloys, superalloy CM247 LC was directionally solidified in an industrial-sized Bridgman furnace. Instead of ceramic cores, Alumina tubes were used inside of the casting specimens. It was found that freckles occur not only on the casting external surfaces, but also appear near the internal interfaces between the ceramic core and superalloys. Meanwhile, the size, initial position, and area of freckle were investigated in various diameters of the specimens. The initial position of the freckle chain reduces when the diameter of the rods increase. Freckle area follows a linear relationship in various diameters and the average freckle fraction is 1.1% of cross sectional area of casting specimens. The flow of liquid metal near the interfaces was stronger than that in the interdendritic region in the mushy zone, and explained why freckle tends to occur on the outer or inner surfaces of castings. This new phenomenon suggests that freckles are more likely to occur on the outer or inner surfaces of the hollow turbine blades.

  18. Erosion–corrosion behaviour of Ni-based superalloy Superni-75

    Indian Academy of Sciences (India)

    The super-heater and re-heater tubes of the boilers used in thermal power plants are ... mechanism, resulting in the tube wall thinning and premature failure. The nickel-based superalloys can be used as boiler tube materials to increase the ...

  19. Proposal for the risk management implementation phase in oil field development project by adding value on the refurbishment of critical equipment

    Directory of Open Access Journals (Sweden)

    Hamid Abdul

    2017-01-01

    Full Text Available Refurbishment process is a conceptual stage in product life cycle. It is utilized in existing equipment in the field by adding value to recondition and repaired equipment. The main interest of this paper is to implement and design risk management implementation phase in oil field development project on the refurbishment of critical equipment in oil and gas industry. This paper is provided base on research and experiences in risk management and learned from practical team in industry which matched by an application in oil field development project in refurbishment of critical equipment. A framework of implementation phase for risk management in oil field development project in refurbishment critical equipment were reviewed and added value on communication skills of the project team to the stakeholder and organization, which support to external body and vice-versa. Risk management framework can be used for reference of refurbishment process with simply process and developed with same concept for the next wide development project in industry.

  20. Development of advanced P/M Ni-base superalloys for turbine disks

    Directory of Open Access Journals (Sweden)

    Garibov Genrikh S.

    2014-01-01

    Full Text Available In the process of evolution of powder metallurgy in Russia the task permanently formulated was the following: to improve strength properties of P/M superalloys without application of additional complex HIPed blanks deformation operation. On the other hand development of a turbine disk material structure to ensure an improvement in aircraft engine performance requires the use of special HIP and heat treatment conditions. To ensure maximum strength properties of disk materials it is necessary to form a structure which would have optimum size of solid solution grains, γ′-phases and carbides. Along with that heating of the material up to a temperature determined by solvus of an alloy ensures a stable and reproducible level of mechanical properties of the disks. The above-said can be illustrated by successful mastering of new complex-alloyed VVP-class superalloys with the use of powder size − 100 μm. Application of special HIP and heat treatment conditions for these superalloys to obtain the desired grain size and the strengthening γ′-phase precipitates allowed a noticeable improvement in ultimate tensile strength and yield strength up to ≥1600 MPa and ≥1200 MPa respectively. 100 hrs rupture strength at 650 ∘C and 750 ∘C was improved up to 1140 MPa and 750 MPa respectively. P/M VVP nickel-base superalloys offer higher characteristics in comparison with many superalloys designed for the same purposes. HIPed disc compacts manufactured from PREP-powder have a homogeneous micro- and macrostructure, a stable level of mechanical properties.

  1. Solid solution strengthening and diffusion in nickel- and cobalt-based superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Rehman, Hamad ur

    2016-07-01

    Nickel and cobalt-based superalloys with a γ-γ{sup '} microstructure are known for their excellent creep resistance at high temperatures. Their microstructure is engineered using different alloying elements, that partition either to the fcc γ matrix or to the ordered γ{sup '} phase. In the present work the effect of alloying elements on their segregation behaviour in nickel-based superalloys, diffusion in cobalt-based superalloys and the temperature dependent solid solution strengthening in nickel-based alloys is investigated. The effect of dendritic segregation on the local mechanical properties of individual phases in the as-cast, heat treated and creep deformed state of a nickel-based superalloy is investigated. The local chemical composition is characterized using Electron Probe Micro Analysis and then correlated with the mechanical properties of individual phases using nanoindentation. Furthermore, the temperature dependant solid solution hardening contribution of Ta, W and Re towards fcc nickel is studied. The room temperature hardening is determined by a diffusion couple approach using nanoindentation and energy dispersive X-ray analysis for relating hardness to the chemical composition. The high temperature properties are determined using compression strain rate jump tests. The results show that at lower temperatures, the solute size is prevalent and the elements with the largest size difference with nickel, induce the greatest hardening consistent with a classical solid solution strengthening theory. At higher temperatures, the solutes interact with the dislocations such that the slowest diffusing solute poses maximal resistance to dislocation glide and climb. Lastly, the diffusion of different technically relevant solutes in fcc cobalt is investigated using diffusion couples. The results show that the large atoms diffuse faster in cobalt-based superalloys similar to their nickel-based counterparts.

  2. Solid solution strengthening and diffusion in nickel- and cobalt-based superalloys

    International Nuclear Information System (INIS)

    Rehman, Hamad ur

    2016-01-01

    Nickel and cobalt-based superalloys with a γ-γ ' microstructure are known for their excellent creep resistance at high temperatures. Their microstructure is engineered using different alloying elements, that partition either to the fcc γ matrix or to the ordered γ ' phase. In the present work the effect of alloying elements on their segregation behaviour in nickel-based superalloys, diffusion in cobalt-based superalloys and the temperature dependent solid solution strengthening in nickel-based alloys is investigated. The effect of dendritic segregation on the local mechanical properties of individual phases in the as-cast, heat treated and creep deformed state of a nickel-based superalloy is investigated. The local chemical composition is characterized using Electron Probe Micro Analysis and then correlated with the mechanical properties of individual phases using nanoindentation. Furthermore, the temperature dependant solid solution hardening contribution of Ta, W and Re towards fcc nickel is studied. The room temperature hardening is determined by a diffusion couple approach using nanoindentation and energy dispersive X-ray analysis for relating hardness to the chemical composition. The high temperature properties are determined using compression strain rate jump tests. The results show that at lower temperatures, the solute size is prevalent and the elements with the largest size difference with nickel, induce the greatest hardening consistent with a classical solid solution strengthening theory. At higher temperatures, the solutes interact with the dislocations such that the slowest diffusing solute poses maximal resistance to dislocation glide and climb. Lastly, the diffusion of different technically relevant solutes in fcc cobalt is investigated using diffusion couples. The results show that the large atoms diffuse faster in cobalt-based superalloys similar to their nickel-based counterparts.

  3. Effects of electrical discharge surface modification of superalloy Haynes 230 with aluminum and molybdenum on oxidation behavior

    International Nuclear Information System (INIS)

    Bai, C.-Y.

    2007-01-01

    The effects of the electrical discharge alloying (EDA) process on improving the high temperature oxidation resistance of the Ni-based superalloy Haynes 230 have been investigated. The 85 at.% Al and 15 at.% Mo composite electrode provided the surface alloying materials. An Al-rich layer is produced on the surface of the EDA specimen alloyed with positive electrode polarity, whereas, many discontinuous piled layers are attached to the surface of the EDA superalloy when negative electrode polarity is selected. The oxidation resistance of the specimen alloyed with positive electrode polarity is better than that of the unalloyed superalloy, and the effective temperature of oxidation resistance of the alloyed layer can be achieved to 1100 o C. Conversely, the oxidation resistance of the other EDA specimen alloyed with negative electrode polarity is even worse than that of the unalloyed superalloy

  4. Focused Ion Beam Nanotomography of ruthenium-bearing nickel-base superalloys with focus on cast-microstructure and phase stability

    International Nuclear Information System (INIS)

    Cenanovic, Samir

    2012-01-01

    The influence of rhenium and ruthenium on the multi component system nickel-base superalloy is manifold and complex. An experimental nickel-base superalloy containing rhenium and ruthenium within defined contents, named Astra, was used to investigate the influences of these two elements on the alloy system. The last stage solidification of nickel-base superalloys after Bridgman casting and the high temperature phase stability of these alloys, could be explored with the aid of focused ion beam nanotomography. FIB-nt therefore was introduced and realized at the chair of General Materials Properties of the University Erlangen-Nuremberg. Cast Astra alloys are like other nickel-base superalloys morphologically very inhomogeneous and affected by segregation. In the interdendritic region different structures with huge γ' precipitates are formed. These inhomogeneities and remaining eutectics degrade the mechanical properties, witch makes an understanding of the subsiding processes at solidification of residual melt important for the casting process and the heat treatment. This is why the last stage solidification in the interdendritic region was analyzed. With the help of focused ion beam nanotomography, three different structures identified from 2-D sections could be assigned to one original 3-D structure. It was pointed out, that only the orientation of the plane of the 2-D cut influences the appearance in the 2-D section. The tomography information was used to explain the development during solidification and to create a model of last stage solidification. The interdendritic region is solidifying under the development of eutectic islands. The structure nucleates eutectically epitaxially at primary dendrite arms, with formation of fine γ/γ' precipitates. During solidification the γ' precipitates coarsen in a rod-like structure, and end up in large γ' precipitates. Simulations and other investigations could approve this model. First three

  5. Cyclic Oxidation of High Mo, Reduced Density Superalloys

    Directory of Open Access Journals (Sweden)

    James L. Smialek

    2015-11-01

    Full Text Available Cyclic oxidation was characterized as part of a statistically designed, 12-alloy compositional study of 2nd generation single crystal superalloys as part of a broader study to co-optimize density, creep strength, and cyclic oxidation. The primary modification was a replacement of 5 wt. % W by 7% or 12% Mo for density reductions of 2%–7%. Compositions at two levels of Mo, Cr, Co, and Re were produced, along with a midpoint composition. Initially, polycrystalline vacuum induction samples were screened in 1100 °C cyclic furnace tests using 1 h cycles for 200 h. The behavior was primarily delimited by Cr content, producing final weight changes of −40 mg/cm2 to −10 mg/cm2 for 0% Cr alloys and −2 mg/cm2 to +1 mg/cm2 for 5% Cr alloys. Accordingly, a multiple linear regression fit yielded an equation showing a strong positive Cr effect and lesser negative effects of Co and Mo. The results for 5% Cr alloys compare well to −1 mg/cm2, and +0.5 mg/cm2 for Rene′ N4 and Rene′ N5 (or Rene′ N6, respectively. Scale phases commonly identified were Al2O3, NiAl2O4, NiTa2O6, and NiO, with (Ni,CoMoO4 found only on the least resistant alloys having 0% Cr and 12% Mo. Scale microstructures were complex and reflected variations in the regional spallation history. Large faceted NiO grains and fine NiTa2O6 particles distributed along NiAl2O4 grain boundaries were typical distinctive features. NiMoO4 formation, decomposition, and volatility occurred for a few high Mo compositions. A creep, density, phase stability, and oxidation balanced 5% Cr, 10% Co, 7% Mo, and 3% Re alloy was selected to be taken forward for more extensive evaluations in single crystal form.

  6. Microstructural aspects of Ni-based superalloy 693

    International Nuclear Information System (INIS)

    Dutta, R.S.; Sengupta, P.; Tewari, R.; Kain, V.; Dey, G.K.; Sharma, A.K.; Raj, K.

    2009-01-01

    Alloy 693 is an austenitic, precipitation-hardenable Ni-based superalloy. It is a promising material for high temperature fuel cell, petrochemical processing industry, high temperature waste and biomass incinerators and as thermal processing equipment, burner nozzles, melter pot material and in other areas. Microstructure plays quite often a major role in regulating the properties of the materials. Keeping this in view, optical microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM) were employed to characterize the microstructure of Alloy 693. Microanalyses of the phases were performed by using electron probe microanalysis (EPMA) and TEM along with energy dispersive spectroscopy (EDS). The alloy in as-received condition under an optic microscope and SEM revealed the presence of predominantly finer intergranular precipitates and randomly distributed coarser precipitates of various morphologies. EPMA of spherical-shaped coarse precipitate indicated that the major constituent of this precipitate has been chromium. Besides this, niobium-rich irregular-shaped coarse precipitate was also detected. The finer grain boundary precipitates in the alloy appeared to be of Cr-carbide. TEM examination on as-received alloy indicated very uniform distribution of a large volume fraction of fine precipitates in the austenite matrix. Selected area diffraction (SAD) pattern, dark-field TEM and detailed analyses confirmed that these fine precipitates have been ordered Ni 3 Al type phase. TEM investigation also revealed the presence of coarse particles of various morphologies. Analyses of such particles indicated this phase as M 6 C type. EDS analyses indicated that the major constituents of these coarse particles have been Cr and Ni. Minor elements like Fe, Al and Nb were also detected in all the particles with some variation of their contents from particle to particle. TEM investigation on annealed (1373 K/30 minutes, WQ) specimen of Alloy 693

  7. Refurbishment, Modernization and Ageing Management Program of The 3MW TRIGA Mark-II Research Reactor of Bangladesh

    International Nuclear Information System (INIS)

    Salam, M. A.

    2013-01-01

    The 3 MW TRIGA MK-II research reactor of Bangladesh Atomic Energy Commission (BAEC) achieved its first criticality on 14 September 1986. The reactor has been used for manpower training, radioisotope production and various R and D activities in the field of neutron activation analysis, neutron radiography and neutron scattering. Reactor Operation and Maintenance Unit (ROMU) is responsible for operation and maintenance of the research reactor. During the past twenty seven years ROMU carried out several refurbishments, replacement, modification and modernization activities in the reactor facility. The major tasks carried out under refurbishment program were replacement of the corrosion damaged N-16 decay tank by a new one, replacement of the fouled shell and tube type heat exchanger by a plate type one, modification of the shielding arrangements around the N-16 decay tank and ECCS system and solving the radial beam port-1 leakage problem. All of these refurbishment activities were performed under an annual development project (ADP) funded by Bangladesh government. BAEC research reactor (RR) was operated by analogue console system from its commissioning to July, 2011. Old analog based console has been replaced by digital console on June, 2012. Modernization program for the reactor control console due to obsolescence and unavailability of spare parts of I and C system was vital to restore the safe operation of the reactor. Considering these facts, installation of a digital control console and I and C system based on the state-of-the-art digital technology became necessary. Reactor digital console system installation tasks were performed under another ADP funded project by Bangladesh government. Now the reactor is operating with the digital control system. Besides this, the Neutron Radiography (NR) facility has been modernized by the addition of a digital neutron radiography set-up at the tangential beam port. The Neutron Scattering (NS) facility also has been upgraded

  8. Refurbishment, Modernization and Ageing Management Program of The 3MW TRIGA Mark-II Research Reactor of Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Salam, M. A. [Atomic Energy Research Establishment, Dhaka (Bangladesh)

    2013-07-01

    The 3 MW TRIGA MK-II research reactor of Bangladesh Atomic Energy Commission (BAEC) achieved its first criticality on 14 September 1986. The reactor has been used for manpower training, radioisotope production and various R and D activities in the field of neutron activation analysis, neutron radiography and neutron scattering. Reactor Operation and Maintenance Unit (ROMU) is responsible for operation and maintenance of the research reactor. During the past twenty seven years ROMU carried out several refurbishments, replacement, modification and modernization activities in the reactor facility. The major tasks carried out under refurbishment program were replacement of the corrosion damaged N-16 decay tank by a new one, replacement of the fouled shell and tube type heat exchanger by a plate type one, modification of the shielding arrangements around the N-16 decay tank and ECCS system and solving the radial beam port-1 leakage problem. All of these refurbishment activities were performed under an annual development project (ADP) funded by Bangladesh government. BAEC research reactor (RR) was operated by analogue console system from its commissioning to July, 2011. Old analog based console has been replaced by digital console on June, 2012. Modernization program for the reactor control console due to obsolescence and unavailability of spare parts of I and C system was vital to restore the safe operation of the reactor. Considering these facts, installation of a digital control console and I and C system based on the state-of-the-art digital technology became necessary. Reactor digital console system installation tasks were performed under another ADP funded project by Bangladesh government. Now the reactor is operating with the digital control system. Besides this, the Neutron Radiography (NR) facility has been modernized by the addition of a digital neutron radiography set-up at the tangential beam port. The Neutron Scattering (NS) facility also has been upgraded

  9. Refurbishing the reactor protection systems of VVER-440/230 and VVER-1000/320 nuclear power plants with exclusively digital IandC systems

    International Nuclear Information System (INIS)

    Martin, M.

    1997-01-01

    The refurbishment of reactor protection systems of nuclear power plants is based on two sets of requirements: engineering aspects such as performance, qualification and licensing, as well as interfaces to other systems; and cost-benefit relationships, ease of service and maintenance as well as installation during scheduled outages. A number of WWER-440 and WWER-1000 nuclear plants have announced their intention to refurbish their protection systems. Since 1994, these plants have been placing orders with Siemens for new protection systems, including the neutron flux monitoring system utilizing the advanced system TELEPERM XS. This exclusively digital IandC system provides an excellent foundation for the remaining plant service life

  10. Microstructural Characterization of a Polycrystalline Nickel-Based Superalloy Processed via Tungsten-Intert-Gas-Shaped Metal Deposition

    Science.gov (United States)

    Clark, Daniel; Bache, Martin R.; Whittaker, Mark T.

    2010-12-01

    Recent trials have produced tungsten-inert-gas (TIG)-welded structures of a suitable scale to allow an evaluation of the technique as an economic and commercial process for the manufacture of complex aeroengine components. The employment of TIG welding is shown to have specific advantages over alternative techniques based on metal inert gas (MIG) systems. Investigations using the nickel-based superalloy 718 have shown that TIG induces a smaller weld pool with less compositional segregation. In addition, because the TIG process involves a pulsed power source, a faster cooling rate is achieved, although this rate, in turn, compromises the deposition rate. The microstructures produced by the two techniques differ significantly, with TIG showing an absence of the detrimental delta and Laves phases typically produced by extended periods at a high temperature using MIG. Instead, an anisotropic dendritic microstructure was evident with a preferred orientation relative to the axis of epitaxy. Niobium was segregated to the interdendritic regions. A fine-scale porosity was evident within the microstructure with a maximum diameter of approximately 5 μm. This porosity often was found in clusters and usually was associated with the interdendritic regions. Subsequent postdeposition heat treatment was shown to have no effect on preexisting porosity and to have a minimal effect on the microstructure.

  11. Predictive Analysis for the Thermal Diffusion of the Plasma-Assisted Machining of Superalloy Inconel-718 Based on Exponential Smoothing

    Directory of Open Access Journals (Sweden)

    Chen Shao-Hsien

    2018-01-01

    Full Text Available Nickel base and titanium base materials have been widely applied to engines in aerospace industry, and these engines are essential components of airplanes. The machining characteristics of aerospace materials may cause machining cutters to be worn down in a short time and thus reduce the accuracy of processing. The plasma-assisted machining adopted in the research is a kind of the complex machining method. In the cases of nickel base and titanium base alloys, the method can heat workpieces in an extremely short duration to soften the materials for the ease of cutting so that the cutting force, cutter wear, and machining cost will all be reduced. The research adopted plasma heating to soften parts of the materials and aimed to explore the heating of nickel base alloy. The temperature variation of the materials was investigated and measured by adjusting the current and feed velocity. Moreover, Inconel-718 superalloy was adopted for the comparison with nickel base alloy for the observation of the influence and change brought by heat, and the method of exponential smoothing was adopted to conduct the prediction and analysis of thermal diffusion for understanding the influence and change brought by electric current on nickel base materials. Finally, given the current from 20 A to 80 A and feed velocity from 1,000 mm/min to 3,000 mm/min, the influence of thermal diffusion was investigated and the related model was built.

  12. RA Reactor operation and maintenance (I-IX), part VII, Task 3.08/04, Refurbishment of the RA reactor; Pogon i odrzavanje reaktora (I-IX), VII Deo, Zadatak 3.08/04 Remont reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Zecevic, V [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    This volume covers the following reports concerned with the maintenance and repair work of the RA reactor: repair of the technical water system; maintenance of the transportation equipment; vacuuming and drying during refurbishment; repair and decontamination of the distillation device; and the report on participation of the operational dosimetry division in the RA reactor refurbishment activities.

  13. Long Term Asset Management Strategy for Refurbishment and Replacement of Nuclear Power Plants in Korea

    International Nuclear Information System (INIS)

    Boo, M.H.; Lee, J.G.; Park, J.S.

    2012-01-01

    LTAM strategy was developed for the component level to efficiently manage aging and obsolescence. Systematic monitoring and proactive measures against aging mechanism will reduce unplanned loss due to failure of large components. Also, financial risk for lost power production will be minimized on the basis of fleet-wide LTAM strategies. (author)

  14. Cyclic Oxidation and Hot Corrosion of NiCrY-Coated Disk Superalloys

    Science.gov (United States)

    Gabb, Timothy P.; Miller, Robert A.; Sudbrack, Chantal K.; Draper, Susan L.; Nesbitt, James A.; Rogers, Richard B.; Telesman, Ignacy; Ngo, Vanda; Healy, Jonathan

    2016-01-01

    Powder metallurgy disk superalloys have been designed for higher engine operating temperatures through improvement of their strength and creep resistance. Yet, increasing disk application temperatures to 704 degrees Centigrade and higher could enhance oxidation and activate hot corrosion in harmful environments. Protective coatings could be necessary to mitigate such attack. Cylindrical coated specimens of disk superalloys LSHR and ME3 were subjected to thermal cycling to produce cyclic oxidation in air at a maximum temperature of 760 degrees Centigrade. The effects of substrate roughness and coating thickness on coating integrity after cyclic oxidation were considered. Selected coated samples that had cyclic oxidation were then subjected to accelerated hot corrosion tests. This cyclic oxidation did not impair the coating's resistance to subsequent hot corrosion pitting attack.

  15. Cyclic Oxidation and Hot Corrosion of NiCrY-Coated Disk Superalloy

    Science.gov (United States)

    Gabb, Tim; Miller, R. A.; Sudbrack, C. K.; Draper, S. L.; Nesbitt, J.; Telesman, J.; Ngo, V.; Healy, J.

    2015-01-01

    Powder metallurgy disk superalloys have been designed for higher engine operating temperatures through improvement of their strength and creep resistance. Yet, increasing disk application temperatures to 704 C and higher could enhance oxidation and activate hot corrosion in harmful environments. Protective coatings could be necessary to mitigate such attack. Cylindrical coated specimens of disk superalloys LSHR and ME3 were subjected to thermal cycling to produce cyclic oxidation in air at a maximum temperature of 760 C. The effects of substrate roughness and coating thickness on coating integrity after cyclic oxidation were considered. Selected coated samples that had cyclic oxidation were then subjected to accelerated hot corrosion tests. The effects of this cyclic oxidation on resistance to subsequent hot corrosion attack were examined.

  16. Liquation Cracking in the Heat-Affected Zone of IN738 Superalloy Weld

    Directory of Open Access Journals (Sweden)

    Kai-Cheng Chen

    2018-05-01

    Full Text Available The main scope of this study investigated the occurrence of liquation cracking in the heat-affected zone (HAZ of IN738 superalloy weld, IN738 is widely used in gas turbine blades in land-based power plants. Microstructural examinations showed considerable amounts of γ’ uniformly precipitated in the γ matrix. Electron probe microanalysis (EPMA maps showed the γ-γ’ colonies were rich in Al and Ti, but lean in other alloy elements. Moreover, the metal carbides (MC, fine borides (M3B2 and M5B3, η-Ni3Ti, σ (Cr-Co and lamellar Ni7Zr2 intermetallic compounds could be found at the interdendritic boundaries. The fracture morphologies and the corresponding EPMA maps confirmed that the liquation cracking in the HAZ of the IN738 superalloy weld resulted from the presence of complex microconstituents at the interdendritic boundaries.

  17. Metallurgical joining of engine parts. Inertia welding of nickel superalloy HP compressor disks

    International Nuclear Information System (INIS)

    Ferte, J.P.

    1993-01-01

    The main part of this paper describes upside metallurgical and mechanical work done at SNECMA, on inertia welding of powder metallurgy nickel base superalloys ASTROLOY and N18, allowing appliance of this process to engine parts : Inertia welding of superalloys leads to deap microstructural changes in the H.A.Z. which have been, as well as upset, correlated to process parameters, weld geometry and base material microstructure; a full mechanical testing of welds shown properties equivalent to base material ones up to 650 C except for fatigue crack growth behavior under specific conditions (T>600 C-hold time at maximum load) which is drastically reduced for in weld plane propagation. A significant improvement of this later property has been done through post-welding heat treatment and optimization of welding parameters. Last part of this paper summarize the main teachings gained, on the complete welding procedure, from welding of scale one parts. (orig.)

  18. On the microstructural origin of primary creep in nickel-base superalloys

    International Nuclear Information System (INIS)

    Heilmaier, M.; Reppich, B.

    1997-01-01

    The nature of primary creep in nickel-base superalloys is strongly correlated to the different hardening species present in the material. In fine-grained single-phase material the classical assumption of a homogeneous dislocation distribution enables the prediction of the transition from normal via sigmoidal to inverse primary creep with decreasing applied stress σ. In coarse-grained material the back stress σ b of hard subgrain boundaries evolving during plastic deformation must be additionally taken into account. Second-phase particles influence creep in a 2-fold manner via reducing the effective stress σ eff , namely directly by the stress σ p * for particle overcoming, and indirectly by increasing the dislocation density ρ. The proposed approach accounts for the observed pronounced normal primary creep in particle-strengthened superalloys. (orig.)

  19. Intermediate Co/Ni-base model superalloys — Thermophysical properties, creep and oxidation

    International Nuclear Information System (INIS)

    Zenk, Christopher H.; Neumeier, Steffen; Engl, Nicole M.; Fries, Suzana G.; Dolotko, Oleksandr; Weiser, Martin; Virtanen, Sannakaisa; Göken, Mathias

    2016-01-01

    The mechanical properties of γ′-strengthened Co–Ni–Al–W–Cr model superalloys extending from pure Ni-base to pure Co-base superalloys have been assessed. Differential scanning calorimetry measurements and thermodynamic calculations match well and show that the γ′ solvus temperature decreases with increasing Co-content. The γ/γ′ lattice misfit is negative on the Ni- and positive on the Co-rich side. High Ni-contents decelerate the oxidation kinetics up to a factor of 15. The creep strength of the Ni-base alloy increases by an order of magnitude with additions of Co before it deteriorates strongly upon higher additions despite an increasing γ′ volume fraction.

  20. Extension of an anisotropic creep model to general high temperature deformation of a single crystal superalloy

    International Nuclear Information System (INIS)

    Pan, L.M.; Ghosh, R.N.; McLean, M.

    1993-01-01

    A physics based model has been developed that accounts for the principal features of anisotropic creep deformation of single crystal superalloys. The present paper extends this model to simulate other types of high temperature deformation under strain controlled test conditions, such as stress relaxation and tension tests at constant strain rate in single crystals subject to axial loading along an arbitrary crystal direction. The approach is applied to the SRR99 single crystal superalloy where a model parameter database is available, determined via analysis of a database of constant stress creep curves. A software package has been generated to simulate the deformation behaviour under complex stress-strain conditions taking into account anisotropic elasticity. (orig.)

  1. Development of superalloys for 1700 C ultra-efficient gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Hiroshi [National Institute for Materials Science, Tsukuba, Ibaraki (Japan). High Temperature Materials Center

    2010-07-01

    Mitigation of global warming is one of the most outstanding issues for the humankind. The Japanese government announced that it will reduce its greenhouse gas emissions by 25% from the 1990 level by 2020 as a medium-term goal. One of the promising approaches to achieving this is to improve the efficiency of thermal power plants emitting one-third of total CO{sub 2} gas in Japan. The key to improving the thermal efficiency is high temperature materials with excellent temperature capabilities allowing higher inlet gas temperatures. In this context, new single crystal superalloys for turbine blades and vanes, new coatings and turbine disk superalloys have been successfully developed for various gas turbine applications, typically 1700 C ultra-efficient gas turbines for next generation combine cycle power plants. (orig.)

  2. Atomic force microscopy imaging to measure precipitate volume fraction in nickel-based superalloys

    International Nuclear Information System (INIS)

    Bourhettar, A.; Troyon, M.; Hazotte, A.

    1995-01-01

    In nickel-based superalloys, quantitative analysis of scanning electron microscopy images fails in providing accurate microstructural data, whereas more efficient techniques are very time-consuming. As an alternative approach, the authors propose to perform quantitative analysis of atomic force microscopy images of polished/etched surfaces (quantitative microprofilometry). This permits the measurement of microstructural parameters and the depth of etching, which is the main source of measurement bias. Thus, nonbiased estimations can be obtained by extrapolation of the measurements up to zero etching depth. In this article, the authors used this approach to estimate the volume fraction of γ' precipitates in a nickel-based superalloy single crystal. Atomic force microscopy images of samples etched for different times show definition, homogeneity, and contrast high enough to perform image analysis. The result after extrapolation is in very good agreement with volume fraction values available from published reports

  3. Computer Aided Design of Ni-Based Single Crystal Superalloy for Industrial Gas Turbine Blades

    Science.gov (United States)

    Wei, Xianping; Gong, Xiufang; Yang, Gongxian; Wang, Haiwei; Li, Haisong; Chen, Xueda; Gao, Zhenhuan; Xu, Yongfeng; Yang, Ming

    The influence of molybdenum, tungsten and cobalt on stress-rupture properties of single crystal superalloy PWA1483 has been investigated using the simulated calculation of JMatPro software which ha s been widely used to develop single crystal superalloy, and the effect of alloying element on the stability of strengthening phase has been revealed by using the Thermo-Calc software. Those properties calculation results showed that the increasing of alloy content could facilitate the precipitation of TCP phases and increase the lattice misfit between γ and γ' phase, and the effect of molybdenum, tantalum was the strongest and that of cobalt was the weakest. Then the chemical composition was optimized, and the selected compositions showed excellent microstructure stability and stress-rupture properties by the confirmation of d-electrons concept and software calculation.

  4. Microstructure of the Nickel-Base Superalloy CMSX-4 Fabricated by Selective Electron Beam Melting

    Science.gov (United States)

    Ramsperger, Markus; Singer, Robert F.; Körner, Carolin

    2016-03-01

    Powder bed-based additive manufacturing (AM) processes are characterized by very high-temperature gradients and solidification rates. These conditions lead to microstructures orders of magnitude smaller than in conventional casting processes. Especially in the field of high performance alloys, like nickel-base superalloys, this opens new opportunities for homogenization and alloy development. Nevertheless, the high susceptibility to cracking of precipitation-hardenable superalloys is a challenge for AM. In this study, electron beam-based AM is used to fabricate samples from gas-atomized pre-alloyed CMSX-4 powder. The influence of the processing strategy on crack formation is investigated. The samples are characterized by optical and SEM microscopy and analyzed by microprobe analysis. Differential scanning calorimetry is used to demonstrate the effect of the fine microstructure on characteristic temperatures. In addition, in situ heat treatment effects are investigated.

  5. On post-weld heat treatment cracking in tig welded superalloy ATI 718Plus

    Science.gov (United States)

    Asala, G.; Ojo, O. A.

    The susceptibility of heat affected zone (HAZ) to cracking in Tungsten Inert Gas (TIG) welded Allvac 718Plus superalloy during post-weld heat treatment (PWHT) was studied. Contrary to the previously reported case of low heat input electron beam welded Allvac 718Plus, where HAZ cracking occurred during PWHT, the TIG welded alloy is crack-free after PWHT, notwithstanding the presence of similar micro-constituents that caused cracking in the low input weld. Accordingly, the formation of brittle HAZ intergranular micro-constituents may not be a sufficient factor to determine cracking propensity, the extent of heat input during welding may be another major factor that influences HAZ cracking during PWHT of the aerospace superalloy Allvac 718Plus.

  6. Heat affected zone liquation cracking in electron beam welded third generation nickel base superalloys

    International Nuclear Information System (INIS)

    Ojo, O.A.; Wang, Y.L.; Chaturvedi, M.C.

    2008-01-01

    The weldability of directionally solidified nickel base superalloy TMS-75 and TMS-75+C was investigated by autogenous bead-on-plate electron beam welding. The analysis of microsegregation that occurred during solidification of the as-cast alloys indicated that while W and Re segregated into the γ dendrites of both the alloys, Ta, Hf and C were rejected into the interdendritic liquid in the TMS-75+C. Heat affected zone intergranular liquation cracking was observed in both the materials and was observed to be closely associated with liquated γ-γ' eutectic microconstituent. The TMS-75+C alloy, however, exhibited a reduced extent of HAZ cracking compared to TMS-75. Suppression of terminal solidification reaction involving non-invariant γ-γ' eutectic transformation due to modification of primary solidification path by carbon addition is suggested to be an important factor contributing to reduced susceptibility of TMS-75+C alloy to HAZ liquation cracking relative to the TMS-75 superalloy

  7. Effect of cobalt on microstructural parameters and mechanical properties of Ni-base single crystal superalloys

    International Nuclear Information System (INIS)

    Suzuki, Takanobu; Imai, Hachiro; Yokokawa, Tadaharu; Kobayashi, Toshiharu; Koizumi, Yutaka; Harada, Hiroshi

    2007-01-01

    The alloying effect of Cobalt (Co) to microstructural parameters and mechanical properties, such as partitioning ratios of alloying elements and creep strength, of Re-bearing Ni-base single crystal superalloys have been investigated. The second generation single crystal superalloys, TMS-82+, Ni-7.8Co-4.9Cr-1.9Mo-8.7W-5.3Al-6.0Ta-2.4Re-0.1Hf, in mass% (8Co) was compared to a Co-free (0Co) and 15 mass% Co (15Co) alloy which had the same chemical composition as TMS-82+ except that Co was changed. It was shown that the partitioning ratios of alloying elements trend to k(=X γ /X' γ )=1, as the content of Co was increased. Furthermore, it was found that there was suitable content of Co for the creep strength under various temperature-stress conditions. (author)

  8. STUDY OF THE MECHANICAL PROPERTIES OF INCONEL 718 SUPERALLOY AFTER HOT TENSILE TESTS

    Directory of Open Access Journals (Sweden)

    Tarcila Sugahara

    2014-10-01

    Full Text Available This research work investigated some important mechanical properties of Inconel 718 superalloy using hot tensile tests like conventional yield strength to 0.2% strain (σe , ultimate strength (σr , and specific elongation (εu . Samples were strained to failure at temperatures of 600°C, 650°C, 700°C, 750°C, 800°C and 850°C and strain rate of 0.5 mm/min (2 × 10–4 s–1 according to ASTM E-8. The results showed higher values σe of yield strength at 700°C, this anomalous behavior can be attributed to the presence of hardening precipitates as observed in the TTT diagram of superalloy Inconel 718. Examination of the sample’s surfaces tensile fracture showed that with increasing temperature test the actuating mechanism changes from intergranular fracture to coalescence of the microcavities.

  9. Phase Transformations in Nickel base Superalloy Inconel 718 during Cyclic Loading at High Temperature

    Directory of Open Access Journals (Sweden)

    Michal Jambor

    2017-06-01

    Full Text Available Nickel base superalloys are hi-tech materials intended for high temperature applications. This property owns a complex microstructure formed by matrix of Ni and variety of precipitates. The type, form and the amount of these phases significantly affect the resulting properties of these alloys. At sufficiently long exposure to high temperatures, the transformation phase can occur, which can lead to degradation of properties of these alloys. A cyclic plastic deformation can accelerate these changes, and they could occur at significantly lower temperatures or in shorter time of exposure. The aim of this study is to describe phase transformation, which can occur by a cyclic plastic deformation at high temperatures in nickel base superalloy Inconel 718.

  10. Grain Boundary Engineering the Mechanical Properties of Allvac 718Plus(Trademark) Superalloy

    Science.gov (United States)

    Gabb, Timothy P.; Telesman, Jack; Garg, Anita; Lin, Peter; Provenzano, virgil; Heard, Robert; Miller, Herbert M.

    2010-01-01

    Grain Boundary Engineering can enhance the population of structurally-ordered "low S" Coincidence Site Lattice (CSL) grain boundaries in the microstructure. In some alloys, these "special" grain boundaries have been reported to improve overall resistance to corrosion, oxidation, and creep resistance. Such improvements could be quite beneficial for superalloys, especially in conditions which encourage damage and cracking at grain boundaries. Therefore, the effects of GBE processing on high-temperature mechanical properties of the cast and wrought superalloy Allvac 718Plus (Allvac ATI) were screened. Bar sections were subjected to varied GBE processing, and then consistently heat treated, machined, and tested at 650 C. Creep, tensile stress relaxation, and dwell fatigue crack growth tests were performed. The influences of GBE processing on microstructure, mechanical properties, and associated failure modes are discussed.

  11. The Effectiveness of a NiCrY-Coating on a Powder Metallurgy Disk Superalloy

    Science.gov (United States)

    Gabb, Timothy P.; Miller, Robert A.; Nesbitt, James A.; Draper, Susan L.; Rogers, Richard B.; Telesman, Jack

    2018-01-01

    Protective ductile coatings could be necessary to mitigate oxidation and corrosion attack on superalloy disks in some turbine engine applications. However, the effects of coatings on fatigue life of the disk during service are an important concern. The objective of this study was to investigate how such a coating could perform after varied post-coating processing. Cylindrical gage fatigue specimens of powder metallurgy-processed disk superalloy LSHR were coated with a NiCrY coating, shot peened, preparation treated, exposed, and then subjected to fatigue at high temperature. The effects of varied shot peening, preparation treatment, and exposures on fatigue life with and without the coating were compared. Each of these variables and several of their interactions significantly influenced fatigue life.

  12. Cyclic plastic response of nickel-based superalloy at room and at elevated temperatures

    Czech Academy of Sciences Publication Activity Database

    Polák, Jaroslav; Petrenec, Martin; Chlupová, Alice; Tobiáš, Jiří; Petráš, Roman

    2015-01-01

    Roč. 57, č. 2 (2015), s. 119-125 ISSN 0025-5300 R&D Projects: GA ČR(CZ) GA13-23652S; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : cyclic plasticity * elevat ed temperature * superalloys * hysteresis loop * statistical theory Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.266, year: 2015

  13. Computational and Experimental Design of Fe-Based Superalloys for Elevated-Temperature Applications

    Energy Technology Data Exchange (ETDEWEB)

    Liaw, Peter K. [Univ. of Tennessee, Knoxville, TN (United States); Fine, Morris E. [Northwestern Univ., Evanston, IL (United States); Ghosh, Gautam [Northwestern Univ., Evanston, IL (United States); Asta, Mark D. [Univ. of California, Berkeley, CA (United States); Liu, Chain T. [Auburn Univ., AL (United States); Sun, Zhiqian [Univ. of Tennessee, Knoxville, TN (United States); Huang, Shenyan [Univ. of Tennessee, Knoxville, TN (United States); Teng, Zhenke [Univ. of Tennessee, Knoxville, TN (United States); Wang, Gongyao [Univ. of Tennessee, Knoxville, TN (United States)

    2012-04-13

    Analogous to nickel-based superalloys, Fe-based superalloys, which are strengthened by coherent B2- type precipitates are proposed for elevated-temperature applications. During the period of this project, a series of ferritic superalloys have been designed and fabricated by methods of vacuum-arc melting and vacuum-induction melting. Nano-scale precipitates were characterized by atom-probe tomography, ultrasmall- angle X-ray scattering, and transmission-electron microscopy. A duplex distribution of precipitates was found. It seems that ferritic superalloys are susceptible to brittle fracture. Systematic endeavors have been devoted to understanding and resolving the problem. Factors, such as hot rolling, precipitate volume fractions, alloy compositions, precipitate sizes and inter-particle spacings, and hyperfine cooling precipitates, have been investigated. In order to understand the underlying relationship between the microstructure and creep behavior of ferric alloys at elevated temperatures, in-situ neutron studies have been carried out. Based on the current result, it seems that the major role of β' with a 16%-volume fraction in strengthening ferritic alloys is not load sharing but interactions with dislocations. The oxidation behavior of one ferritic alloy, FBB8 (Fe-6.5Al-10Ni-10Cr-3.4Mo-0.25Zr-0.005B, weight percent), was studied in dry air. It is found that it possesses superior oxidation resistance at 1,023 and 1,123 K, compared with other creep-resistant ferritic steels [T91 (modified 9Cr-1Mo, weight percent) and P92 (9Cr-1.8W-0.5Mo, weight percent)]. At the same time, the calculation of the interfacial energies between the -iron and B2-type intermetallics (CoAl, FeAl, and NiAl) has been conducted.

  14. Interdiffusion between Ni-based superalloy and MCrAlY coating

    DEFF Research Database (Denmark)

    Dahl, Kristian Vinter; Hald, John; Horsewell, Andy

    2006-01-01

    Interdiffusion at the interface between a Co-36.5Ni-17.5Cr-8Al-0.5Y, MCrAlY coating and the underlying IN738 superalloy was studied in a large matrix of specimens isothermally heat treated for up to 12,000 hours at temperatures 875oC, 925oC or 950oC. Modelled results using the finite difference...

  15. Rapid solidification and dynamic compaction of Ni-base superalloy powders

    Science.gov (United States)

    Field, R. D.; Hales, S. J.; Powers, W. O.; Fraser, H. L.

    1984-01-01

    A Ni-base superalloy containing 13Al-9Mo-2Ta (in at. percent) has been characterized in both the rapidly solidified condition and after dynamic compaction. Dynamically compacted specimens were examined in the as-compacted condition and observations related to current theories of interparticle bonding. In addition, the recrystallization behavior of the compacted material at relatively low temperature (about 0.5-0.75 Tm) was investigated.

  16. Crystallographic, microstructure and mechanical characteristics of dynamically processed IN718 superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, A.D., E-mail: ads.hpu@gmail.com [Department of Physics, Himachal Pradesh University, Shimla 171005 (India); Sharma, A.K. [Terminal Ballistics Research Laboratory, Chandigarh 160030 (India); Thakur, N. [Department of Physics, Himachal Pradesh University, Shimla 171005 (India)

    2014-06-01

    Highlights: • Measurement of detonation velocity and compaction of powder are achieved together. • A plastic explosive detonation results into dense compacts without grain-growth. • We have studied crystallographic, micromechanical and microstructural features. • The results show no segregation within the compacts. • Density (98%), microhardness (470 ± 3)H{sub v}, microstrain (0.3%), UTS (806 MPa) are obtained. - Abstract: Dynamic consolidation of IN718 superalloy powder without grain-growth and negligible density gradient is accomplished through explosively generated shock wave loading. The compaction of powder and measurement of detonation velocity are achieved successfully in a single-shot experiment by employing instrumented detonics. A plastic explosive having a detonation velocity of the order of 7.1 km/s in a direct proximity with superalloy powder is used for the consolidation process. The compacted specimens are examined for structural, microstructure and mechanical characteristics. X-ray diffraction (XRD) study suggests intact crystalline structure of the compacts. A small micro-strain (0.26%) is observed by using Williamson–Hall method. Wavelength dispersive spectroscopy indicates no segregation within the shock processed superalloy compacted specimens. The monoliths investigated for fractography by using field emission scanning electron microscopy (FE-SEM) show original dendritic structure accompanied by re-solidified molten regions across the interparticle boundaries. Depth-sensing indentations (at 1.96 N) on compacted specimens show excellent micro-hardness of the order of (470 ± 3)H{sub v}. Tensile and compressive strengths of the superalloy monolith are observed to be 806 and 822 MPa, respectively.

  17. On γ and γ' phases composition in IN-100 superalloy after high-temperature exposure

    International Nuclear Information System (INIS)

    Matteazzi, P.; Principi, G.; Ramous, E.

    1981-01-01

    The chemistry and volume fraction of UPSILON' phase in IN-100 superalloy after high-temperature exposure in furnace and in service have been examined. Increasing the time of exposure aluminium plus titanium content remains nearly constant and very close to 25 at.%; the little decrease of nickel together with the increase of iron and molybdenum suggest that the last two elements are preferentially occupying Ni-type sites, according to the pair potential model of UPSILON'. (orig.)

  18. Discussion of "Investigation of Oxide Bifilms in Investment Cast Superalloy IN100 Parts I and II"*

    Science.gov (United States)

    Campbell, John

    2017-10-01

    Fuchs and Kaplan carried out experiments in an attempt to ascertain whether oxide bifilms were present in a vacuum-cast Ni-base superalloy but concluded negatively. Although this author challenged their interpretation of their findings, both parties had overlooked the presence in the alloy of boron which is now known to inhibit bifilm formation. However, even though boron can help significantly, improved filling system designs remain important if other damaging entrainment defects are to be avoided.

  19. Analysis of microstructure in electro-spark deposited IN718 superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Anisimov, E.; Khan, A.K.; Ojo, O.A., E-mail: olanrewaju.ojo@umanitoba.ca

    2016-09-15

    The microstructure of electro-spark deposited (ESD) superalloy IN718 was studied by the use of scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques. In converse to general assumption, the extremely high cooling rate involved in the ESD process did not produce partitionless solidification that is devoid of second phase microconstituents in the material, nano-sized Laves phase and MC carbide particles were observed within the deposited layer. Notwithstanding the several thermal cycles involved in the process, the extremely low heat input of the process produced a deposited region that is free of the main strengthening phase of the alloy, γ″ phase precipitates, which is in contrast to what have been reported on laser deposition. Nevertheless, application of the standard full heat treatment of the alloy resulted in extensive formation of the γ″ phase precipitates and δ phase precipitates, the most stable secondary phase of the alloy, with nearly, if not complete, dissolution of the Laves phase particles. Furthermore, the XPS analysis done in the study revealed the formation of nano-oxides within the deposited layer, which increased the microhardness of the superalloy in the as-deposited condition and inhibited its grain growth during post-process heat treatment. The microstructure analysis done in this work is crucial to the understanding of properties of the superalloy processed by the ESD technique. - Highlights: •Electron microscopy analyses of electro-spark deposited IN 718 superalloy were performed. •Nano-sized secondary phase particles were observed within the deposited layer. •The study shows that the ESD did not produce partitionless solidification of the alloy.

  20. CYCLIC STRAIN LOCALIZATION IN CAST NICKEL BASED SUPERALLOY INCONEL 792-5A AT ROOM TEMPERATURE

    Czech Academy of Sciences Publication Activity Database

    Petrenec, Martin; Man, Jiří; Obrtlík, Karel; Polák, Jaroslav

    308/2005, č. 86 (2005), s. 269-274 ISSN 1429-6055. [Metody oceny struktury oraz wlasności materialów i wyrobów. Ustroń-Jaszowiec, 07.12.2005-09.12.2005] Institutional research plan: CEZ:AV0Z20410507 Keywords : low cycle fatigue * superalloy * cyclic strain localization Subject RIV: JL - Materials Fatigue, Friction Mechanics

  1. Misorientation related microstructure at the grain boundary in a nickel-based single crystal superalloy

    International Nuclear Information System (INIS)

    Huang, Ming; Zhuo, Longchao; Liu, Zhanli; Lu, Xiaogang; Shi, Zhenxue; Li, Jiarong; Zhu, Jing

    2015-01-01

    The mechanical properties of nickel-based single crystal superalloys deteriorate with increasing misorientation, thus the finished product rate of the casting of single crystal turbine airfoils may be reduced due to the formation of grain boundaries especially when the misorientation angle exceeds to some extent. To this day, evolution of the microstructures at the grain boundaries with misorientation and the relationship between the microstructures and the mechanical properties are still unclear. In this work a detailed characterization of the misorientation related microstructure at the grain boundary in DD6 single crystal superalloy has been carried out using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques; the elemental distribution at the grain boundaries has been analyzed by energy dispersive (EDS) X-ray mapping; and the effect of precipitation of μ phases at the grain boundary on the mechanical property has been evaluated by finite element calculation. It is shown that the proportion of γ phase at the grain boundaries decreases, while the proportion of γ′ phase at the grain boundaries increases with increasing misorientation; the μ phase is precipitated at the grain boundaries when the misorientation angle exceeds about 10° and thus it could lead to a dramatic deterioration of the mechanical properties, as well as that the enrichment of Re and W gradually disappears as the misorientation angle increases. All these factors may result in the degradation of the mechanical properties at the grain boundaries as the misorientation increases. Furthermore, the finite element calculation confirms that precipitation of μ phases at the grain boundary is responsible for the significant deterioration of the mechanical properties when the misorientation exceeds about 10°. This work provides a physical imaging of the microstructure for understanding the relationship between the mechanical properties and the misorientation

  2. Behaviour and damage of a superalloy prepared by hot isostatic compression

    International Nuclear Information System (INIS)

    Dubiez-Le-Goff, Sophie

    2003-01-01

    This work deals with the behavior and damage of Udimet 720 superalloy prepared by hot isostatic compression. This alloy is considered for manufacturing turbine disks of high temperature reactors (HTR). The material choice for HTR turbine disk depends on the following criteria: a good creep resistance until 700 C, a good behaviour under an helium impure atmosphere, a possible implementation under a disk of 1.5 m diameter. (author) [fr

  3. The influence of high temperature on the microstructure properties of Ni-based superalloy

    Czech Academy of Sciences Publication Activity Database

    Luptáková, Natália; Král, Petr; Dymáček, Petr

    2014-01-01

    Roč. 14, č. 4 (2014), s. 190-198 ISSN 1335-8987. [Deformation and Fracture in PM Materials. Stará Lesná, 26.10.2014-29.10.2014] R&D Projects: GA MPO FR-TI4/406; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : powder materials * Ni-based PM superalloy * grip of creep machine * oxidation Subject RIV: JG - Metallurgy

  4. Anisotropic constitutive equations for the viscoplastic behaviour of the single crystal superalloy CMSX-4

    International Nuclear Information System (INIS)

    Fleury, G.; Schubert, F.

    1997-09-01

    Nickel-base superalloy blades of the first rotor stage in a gas turbine have to withstand extremely severe thermomechanical loading conditions. Single crystal blades exhibit a highly anisotropic deformation behaviour and are subjected to triaxial stress fields induced by complex cooling systems. Consequently the prediction of their deformation behaviour requires constitutive equations based on multiaxial formulations. The microstructural evolution of γ/γ' superalloys during the service time modifies the material properties and has therefore to be taken into account in the constitutive equations. For the modelling of the anisotropic, viscoplastic behaviour of single crystal blades taking into account the evolution of the microstructure, a microstructure-dependent, orthotropic Hills potential, whose anisotropy coefficients are connected to the edge length of the γ'-particles, is applied. The prediction was validated by investigating the deformation behaviour of the superalloy CMSX-4 in the range of temperatures [750 C-950 C]. If the shape of γ'-particles remain cubic, for example, in creep testing at low temperatures (up to about 850 C), the microstructure-dependent potential leads to the cubic version of the Hills potential. The prediction is in good agreement with creep results for left angle 001 right angle - and left angle 111 right angle - orientated specimens but overestimates the creep resistance of left angle 011 right angle - orientated specimens. (orig.)

  5. Phase-transformation and subgrain-deformation characteristics in a cobalt-based superalloy

    International Nuclear Information System (INIS)

    Benson, M.L.; Reetz, B.; Liaw, P.K.; Reimers, W.; Choo, H.; Brown, D.W.; Saleh, T.A.; Klarstrom, D.L.

    2011-01-01

    Research highlights: → The mechanical behavior of a cobalt-based superalloy was investigated. → Two diffraction techniques were used to study deformation mechanisms of materials. → In-situ neutron diffraction provides the volume-averaged information. → The peak-profile analysis reveals the information on a subgrain level. → The material exhibited a transformation texture for the HCP phase under loading. - Abstract: A complimentary set of experiments, in situ neutron diffraction and ex situ synchrotron X-ray diffraction, were used to study the phase-transformation and subgrain-deformation characteristics of a cobalt-based superalloy. The neutron diffraction indicated a strain-induced phase transformation in the cobalt-based superalloy under uniaxial tension and compression. The synchrotron X-ray diffraction revealed stacking-fault accumulation and twinning under the same loading conditions. The extent of transformation was found to be greater under tension than under compression. Tensile plastic strains below 2% were accommodated by the stacking-fault creation, while those greater than 2% were accommodated by the phase transformation. Twinning was found to be more active under compressive loading than under tensile loading.

  6. Molecular dynamics simulation of edge dislocation piled at cuboidal precipitate in Ni-based superalloy

    International Nuclear Information System (INIS)

    Yashiro, Kisaragi; Naito, Masato; Tomita, Yoshihiro

    2003-01-01

    In order to clarify the fundamental mechanism of dislocations in the γ/γ' microstructure of Ni-based superalloy, three molecular dynamics simulations are conducted on the behavior of edge dislocations nucleated from a free surface and proceeding in the pure Ni matrix (γ) toward cuboidal Ni 3 Al precipitates (γ') under shear force. One involves dislocations near the apices of two precipitates adjoining each other with the distance of 0.04 μm, as large as the width of the γ channel in real superalloys. Others simulate dislocations piled at the precipitates as well, however, the scale of the microstructure is smaller than that in real superalloys by one order of magnitude, and one of them have precipitates with atomistically sharp edge. Dislocations are pinned at precipitates and bowed-out in the γ channel, then they begin to penetrate into the precipitate at the edge in both the real-scale and smaller microstructures when the precipitates have blunt edges. On the other hand, an edge dislocation splits into a superpartial in the γ' precipitate and a misfit screw dislocation bridging between two adjacent precipitates at the atomistically sharp edge of γ' precipitates. It is also observed that two superpartials glide in the precipitate as a superdislocation with anti-phase boundary (APB), of which the width is evaluated to be about 4 nm. (author)

  7. Kink structures induced in nickel-based single crystal superalloys by high-Z element migration

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Fei; Zhang, Jianxin [Key Laboratory for Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Mao, Shengcheng [Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124 (China); Jiang, Ying [Center of Electron Microscopy and State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Feng, Qiang [National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Shen, Zhenju; Li, Jixue; Zhang, Ze [Center of Electron Microscopy and State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Han, Xiaodong [Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124 (China)

    2015-01-05

    Highlights: • Innovative kink structures generate at the γ/γ′ interfaces in the crept superalloy. • Clusters of heavy elements congregate at the apex of the kinks. • Dislocation core absorbs hexagonal structural high-Z elements. - Abstract: Here, we investigate a new type of kink structure that is found at γ/γ′ interfaces in nickel-based single crystal superalloys. We studied these structures at the atomic and elemental level using aberration corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The core of the dislocation absorbs high-Z elements (i.e., Co and Re) that adopt hexagonal arrangements, and it extrudes elements (i.e., Ni and Al) that adopt face centered cubic (fcc) structures. High-Z elements (i.e., Ta and W) and Cr, which is a low-Z element, are stabilized in body centered cubic (bcc) arrangements; Cr tends to behave like Re. High-Z elements, which migrate and adopt a hexagonal structure, induce kink formation at γ/γ′ interfaces. This process must be analyzed to fully understand the kinetics and dynamics of creep in nickel-based single crystal superalloys.

  8. Microstructural response to heat affected zone cracking of prewelding heat-treated Inconel 939 superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, M.A., E-mail: mgonzalez@comimsa.com.mx [Facultad de Ingenieria Mecanica y Electrica (FIME-UANL), Av. Universidad s/n. Ciudad Universitaria, C.P.66451 San Nicolas de los Garza, N.L. (Mexico); Martinez, D.I., E-mail: dorairma@yahoo.com [Facultad de Ingenieria Mecanica y Electrica (FIME-UANL), Av. Universidad s/n. Ciudad Universitaria, C.P.66451 San Nicolas de los Garza, N.L. (Mexico); Perez, A., E-mail: betinperez@hotmail.com [Facultad de Ingenieria Mecanica y Electrica (FIME-UANL), Av. Universidad s/n. Ciudad Universitaria, C.P.66451 San Nicolas de los Garza, N.L. (Mexico); Guajardo, H., E-mail: hguajardo@frisa.com [FRISA Aerospace, S.A. de C.V., Valentin G. Rivero No. 200, Col. Los Trevino, C.P. 66150, Santa Caterina N.L. (Mexico); Garza, A., E-mail: agarza@comimsa.com [Corporacion Mexicana de Investigacion en Materiales S.A. de C.V. (COMIMSA), Ciencia y Tecnologia No.790, Saltillo 400, C.P. 25295 Saltillo Coah. (Mexico)

    2011-12-15

    The microstructural response to cracking in the heat-affected zone (HAZ) of a nickel-based IN 939 superalloy after prewelding heat treatments (PWHT) was investigated. The PWHT specimens showed two different microstructures: 1) spherical ordered {gamma} Prime precipitates (357-442 nm), with blocky MC and discreet M{sub 23}C{sub 6} carbides dispersed within the coarse dendrites and in the interdendritic regions; and 2) ordered {gamma} Prime precipitates in 'ogdoadically' diced cube shapes and coarse MC carbides within the dendrites and in the interdendritic regions. After being tungsten inert gas welded (TIG) applying low heat input, welding speed and using a more ductile filler alloy, specimens with microstructures consisting of spherical {gamma} Prime precipitate particles and dispersed discreet MC carbides along the grain boundaries, displayed a considerably improved weldability due to a strong reduction of the intergranular HAZ cracking associated with the liquation microfissuring phenomena. - Highlights: Black-Right-Pointing-Pointer Homogeneous microstructures of {gamma} Prime spheroids and discreet MC carbides of Ni base superalloys through preweld heat treatments. Black-Right-Pointing-Pointer {gamma} Prime spheroids and discreet MC carbides reduce the intergranular HAZ liquation and microfissuring of Nickel base superalloys. Black-Right-Pointing-Pointer Microstructure {gamma} Prime spheroids and discreet blocky type MC carbides, capable to relax the stress generated during weld cooling. Black-Right-Pointing-Pointer Low welding heat input welding speeds and ductile filler alloys reduce the HAZ cracking susceptibility.

  9. A continuum model for the anisotropic creep of single crystal nickel-based superalloys

    International Nuclear Information System (INIS)

    Prasad, Sharat C.; Rajagopal, K.R.; Rao, I.J.

    2006-01-01

    In this paper, we extend the constitutive theory developed by Prasad et al. [Prasad SC, Rao IJ, Rajagopal KR. A continuum model for the creep of single crystal nickel-base superalloys. Acta Mater 2005;53(3):669-79], to describe the creep anisotropy associated with crystallographic orientation in single crystal nickel-based superalloys. The constitutive theory is cast within a general thermodynamic framework that has been developed to describe the response of materials capable of existing in multiple stress free configurations ('natural configurations'). Central to the theory is the prescription of the forms for the stored energy and rate of dissipation functions. The stored energy reflects the fact that the elastic response exhibits cubic symmetry. The model takes into account the fact that the symmetry of single crystals does not change with inelastic deformation. The rate of dissipation function is also chosen to be anisotropic, in that it reflects invariance to transformations that belong to the cubic symmetry group. The model is used to simulate uniaxial creep of single crystal nickel-based superalloy CMSX-4 for loading along the , and orientations. The predictions of the theory agree well with the experimental data

  10. A new method to predict the metadynamic recrystallization behavior in a typical nickel-based superalloy

    International Nuclear Information System (INIS)

    Lin, Y.C.; Chen, Xiao-Min; Chen, Ming-Song; Wen, Dong-Xu; Zhou, Ying; He, Dao-Guang

    2016-01-01

    The metadynamic recrystallization (MDRX) behaviors of a typical nickel-based superalloy are investigated by two-pass hot compression tests and four conventional stress-based conventional approaches (offset stress method, back-extrapolation stress method, peak stress method, and mean stress method). It is found that the conventional stress-based methods are not suitable to evaluate the MDRX softening fractions for the studied superalloy. Therefore, a new approach, 'maximum stress method', is proposed to evaluate the MDRX softening fraction. Based on the proposed method, the effects of deformation temperature, strain rate, initial average grain size, and interpass time on MDRX behaviors are discussed in detail. Results show that MDRX softening fraction is sensitive to deformation parameters. The MDRX softening fraction rapidly increases with the increase of deformation temperature, strain rate, and interpass time. The MDRX softening fraction in the coarse-grain material is lower than that in the fine-grain material. Moreover, the observed microstructures indicate that the initial coarse grains can be effectively refined by MDRX. Based on the experimental results, the kinetics equations are established and validated to describe the MDRX behaviors of the studied superalloy. (orig.)

  11. Implementation of a structural dependent model for the superalloy IN738LC in ABAQUS-code

    International Nuclear Information System (INIS)

    Wolters, J.; Betten, J.; Penkalla, H.J.

    1994-05-01

    Superalloys, mainly consisting of nickel, are used for applications in aerospace as well as in stationary gas turbines. In the temperature range above 800 C the blades, which are manufactured of these superalloys, are subjected to high centrifugal forces and thermal induced loads. For computer based analysis of the thermo-mechanical behaviour of the blades models for the stress-strain behaviour are necessary. These models have to give a reliable description of the stress-strain behaviour, with emphasis on inelastic affects. The implementation of the model in finite element codes requires a numerical treatment of the constitutive equations with respect to the given interface of the used code. In this paper constitutive equations for the superalloy IN738LC are presented and the implementation in the finite element code ABAQUS with the numerical preparation of the model is described. In order to validate the model calculations were performed for simple uniaxial loading conditions as well as for a complete cross section of a turbine blade under combined thermal and mechanical loading. The achieved results were compared with those of additional calculations by using ABAQUS, including Norton's law, which was already implemented in this code. (orig.) [de

  12. Tensile properties and temperature-dependent yield strength prediction of GH4033 wrought superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jianzuo [State Key Laboratory of Coal Mine Disaster Dynamics and Control and College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Li, Weiguo, E-mail: wgli@cqu.edu.cn [State Key Laboratory of Coal Mine Disaster Dynamics and Control and College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Zhang, Xianhe; Kou, Haibo; Shao, Jiaxing; Geng, Peiji; Deng, Yong [State Key Laboratory of Coal Mine Disaster Dynamics and Control and College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Fang, Daining [LTCS and College of Engineering, Peking University, Beijing 100871 (China)

    2016-10-31

    The tensile properties of superalloy GH4033 have been evaluated at temperatures ranging from room temperature to 1000 °C. Fracture surfaces and precipitation were observed using a field-emission scanning electron microscope (FE-SEM). The alloy mainly consisted of γ’ precipitate particles homogeneously dispersed in the γ matrix interior. The effects of dynamic strain aging and precipitation on the strength were verified. A temperature-dependent yield strength model was developed to describe the temperature and precipitation effects on the alloy's yield behaviour. The model is able to consider the effect of precipitation strengthening on the yield strength. The yield behaviour of the precipitation-strengthened superalloy was demonstrated to be adequately predictable over a wide range of temperatures. Note that this model reflects the quantitative relationship between the yield strength of the precipitation-strengthened superalloy and the temperature, the elastic modulus, the specific heat capacity at constant pressure, Poisson's ratio, the precipitate particle size and the volume fraction of the particles.

  13. The High Temperature Tensile and Creep Behaviors of High Entropy Superalloy.

    Science.gov (United States)

    Tsao, Te-Kang; Yeh, An-Chou; Kuo, Chen-Ming; Kakehi, Koji; Murakami, Hideyuki; Yeh, Jien-Wei; Jian, Sheng-Rui

    2017-10-04

    This article presents the high temperature tensile and creep behaviors of a novel high entropy alloy (HEA). The microstructure of this HEA resembles that of advanced superalloys with a high entropy FCC matrix and L1 2 ordered precipitates, so it is also named as "high entropy superalloy (HESA)". The tensile yield strengths of HESA surpass those of the reported HEAs from room temperature to elevated temperatures; furthermore, its creep resistance at 982 °C can be compared to those of some Ni-based superalloys. Analysis on experimental results indicate that HESA could be strengthened by the low stacking-fault energy of the matrix, high anti-phase boundary energy of the strengthening precipitate, and thermally stable microstructure. Positive misfit between FCC matrix and precipitate has yielded parallel raft microstructure during creep at 982 °C, and the creep curves of HESA were dominated by tertiary creep behavior. To the best of authors' knowledge, this article is the first to present the elevated temperature tensile creep study on full scale specimens of a high entropy alloy, and the potential of HESA for high temperature structural application is discussed.

  14. French experience on renewing I and C systems in NPPs. Feedback from assessing nuclear instrumentation system (RPN) refurbishment at French CP0-series plants

    International Nuclear Information System (INIS)

    Elsensohn, O.; Fradet, F.; Peron, J.C.; Soubies, B.

    2003-01-01

    In 1996, the utility operating France's nuclear power plants launched feasibility studies for the refurbishment of the nuclear instrumentation system (RPN classed category A) installed in its CPO-series (900 MWe) units. The system was ultimately upgraded with digital I and C system, using a SPINLINE 3 platform. This article describes feedback from an evaluation conducted on the refurbishment by the Institute of Radiological Protection and Nuclear Safety (IRSN), technical support arm of the Directorate General for Nuclear Safety and Radiological Protection (DGSNR). The study begins with a historical overview of the refurbishing operation, then discusses the IRSN assessment method and the lessons learned from this first major revamp of an I and C system in the French nuclear reactor series. Based on its previous experience in evaluating I and C systems for P4/P'4 (1300 MWe) and N4 (1450 MWe) plants and to account for the first-ever aspect of such an upgrade, IRSN partitioned its assessment into four phases. This approach enabled taking into account the impact of RPN refurbishment at every level - system, hardware and qualification, software, operation, onsite requalification, health physics, fire protection and human factors. All six units in the CPO series have now been equipped with the new digital RPN. (authors)

  15. Vacuuming and drying during refurbishment, Task 3.08/04-11; Podzadatak 3.08/04-11 Vakuumiranje i susenje u toku remonta

    Energy Technology Data Exchange (ETDEWEB)

    Nikolic, M; Crnilovic, M [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    The following tasks were completed during RA reactor refurbishment: vacuuming the gas system; vacuuming of the heavy water system for collecting the leftover heavy water; drying the heavy water system to remove the demineralized water; drying the distillation system; vacuuming the heavy water system before filling with heavy water; leak testing of the complete reactor system.

  16. A Closed-Loop Supply Chain under Retail Price and Quality Dependent Demand with Remanufacturing and Refurbishing

    Science.gov (United States)

    Christy, A. Y.; Fauzi, B. N.; Kurdi, N. A.; Jauhari, W. A.; Saputro, D. R. S.

    2017-06-01

    The demand of a product is linearly dependent on the retail price and quality of the product. We address a closed-loop supply chain where the manufacturer manufactures products according to the demand and sells them through a retailer in the market. A third party collects the used products from costumers and sends to the manufacturer to increase the quality. If the products can retrieve the original quality, thus the process is called remanufacturing. Not every products can retrieve the original quality, thus manufacturer refurbish this products with lower price. We construct four different scenarios - centralized and decentralized led by manufacturer, retailer, and third party. From the comparison of the result obtained in the numerical example, we conclude that the joint profit obtained under centralized, manufacturer-led, and retailer-led policies is higher than third party-led policy.

  17. A study of design features of civil works of nuclear installations facilitating their eventual refurbishing, renewal, dismantling or demolition

    International Nuclear Information System (INIS)

    Paton, A.A.; Benwell, P.; Irwin, T.F.; Hunter, I.

    1984-03-01

    This report describes a study that has been carried out to identify civil engineering features which could be incorporated in future gas cooled and light water cooled nuclear power plants to facilitate their decommissioning. The report reviews the problems likely to be met in decommissioning present day nuclear power plants and concludes that there is a number of such features which could be introduced in future designs to overcome or eliminate the problems. The report identifies and describes these features and recommends that further work be carried out to confirm their feasibility. The study briefly considered the possibility of refurbishing nuclear plants and concluded that this is not a realistic option in present circumstances. (author)

  18. The Architectural and Environmental Refurbishment of Industrialised Residential Construction. The example of the Selva Cafaro Quarter in Naples

    Directory of Open Access Journals (Sweden)

    Massimo Perriccioli

    2012-10-01

    Full Text Available This essay presents the experimental research conducted over the past years by the CHED (Concept House and Environmental Design Research Unit at the “Eduardo Vittoria” School of Architecture and Design in Ascoli Piceno, focused on the theme of Social Housing. The CHED is a temporary research team that proposes a union between diverse know-how, cultures, skills and specialisations, working towards a method of theoretical and conceptual investigation and design and building experiments in the field of innovative construction for sustainable dwelling. In particular, the experience outlined in this text relates to a design experiment completed between 2010 and 2011 and outside the borders of the Marche region, in agreement with the City of Naples' Assessorato all’Edilizia e al Centro Storico (Department of Building and the Historical Centre and focused on the architectural and environmental refurbishment of the residential quarter of Selva Cafaro in San Pietro a Patierno (Naples.

  19. Performance evaluation of operational energy use in refurbishment, reuse, and conservation of heritage buildings for optimum sustainability

    Directory of Open Access Journals (Sweden)

    O.K. Akande

    2016-09-01

    Full Text Available The operational phase of a building project has increasingly gained importance with their energy performance becoming valuable and determining their operational excellence. In most heritage building projects (HBPs, the operational energy use aspects are less considered, and a systematic way of analyzing their energy performance following project delivery is often lacking. The aim of this study is to evaluate the operational performance of refurbishment and reuse of UK listed church projects. The objective is to assess the operational energy use with a view to optimizing their sustainable performance. The methodology includes eight selected case study buildings refurbished and converted for multipurpose use. The case study approach provided qualitative insights into how the study contributes to a more structured requirements for energy management in HBPs with specific attention to energy-efficient building operations. The findings show the need to focus on fundamental areas of operational management (i.e. by developing and implementing more focused policy on operational energy performance of heritage buildings to minimize the energy required to operate them. The challenges of implementing changes in operational energy performance improvement of heritage buildings are addressed in the form of recommendations that could lead to real results. The study concludes that leveraging these areas requires commitment from all heritage building stakeholders because they all have substantial roles in harmonizing the requirement for the project׳s sustainability and not just the building operators. Meanwhile, baseline project planning, periodic updating, monitoring, and managing the energy use pattern are suggested as measures that could greatly facilitate better energy performance to optimizing their sustainable reuse compared with the traditional approach of trying to improve their thermal performance.

  20. Microstructural characterization, formation mechanism and fracture behavior of the needle δ phase in Fe–Ni–Cr type superalloys with high Nb content

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Yongquan, E-mail: luckyning@nwpu.edu.cn [School of Materials Science & Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); Huang, Shibo [Anshan Iron & Steel Group Corporation Bayuquan Subsidiary Company, Bayuquan 115007 (China); Fu, M.W. [Department of Mechanical Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Dong, Jie [Inspection & Research Institute of Boiler & Pressure Vessel of Jiangxi Province, Nanchang 330029 (China)

    2015-11-15

    Microstructural characterization, formation mechanism and fracture behavior of the needle δ phase in Fe–Ni–Cr type superalloys with high Nb content (GH4169, equivalent to Inconel 718) have been quantitatively investigated in this research. The typical microstructures of δ phases with the stick, mixed and needle shapes obviously present in Inconel 718 after the isothermal upsetting at the temperature of 980–1060 °C with the initial strain rate of 10{sup −3}–10{sup −1} s{sup −1}. It is found that the shape of the δ phase has a great effect on the mechanical properties of the alloy, viz., the stick δ phase behaves good plasticity and the needle δ phase has good strength. In addition, the needle δ phase can be used to control the grain size as it can prevent grain growth. The combined effect of the localized necking and microvoid coalescence leads to the final ductile fracture of the GH4169 components with the needle δ phase. Both dislocation motion and atom diffusion are the root-cause for the needle δ phase to be firstly separated at grain boundary and then at sub-boundary. The formation mechanism of the needle δ phase is the new finding in this research. Furthermore, it is the primary mechanism for controlling the needle δ phase in Fe–Ni–Cr type superalloys with high Nb content. - Highlights: • Shape of the δ phase takes great effect on mechanical property. • Needle δ phase plays a great role to prevent grain growth. • Needle δ phase can enhance the fracture strength. • Microstructure mechanism of the needle δ phase has been investigated. • Fracture behavior of the needle δ phase has been studied.

  1. First-principles calculations for the elastic properties of Ni-base model superalloys: Ni/Ni3Al multilayers

    International Nuclear Information System (INIS)

    Yun-Jiang, Wang; Chong-Yu, Wang

    2009-01-01

    A model system consisting of Ni[001](100)/Ni 3 Al[001](100) multi-layers are studied using the density functional theory in order to explore the elastic properties of single crystal Ni-based superalloys. Simulation results are consistent with the experimental observation that rafted Ni-base superalloys virtually possess a cubic symmetry. The convergence of the elastic properties with respect to the thickness of the multilayers are tested by a series of multilayers from 2γ'+2γ to 10γ'+10γ atomic layers. The elastic properties are found to vary little with the increase of the multilayer's thickness. A Ni/Ni 3 Al multilayer with 10γ'+10γ atomic layers (3.54 nm) can be used to simulate the mechanical properties of Ni-base model superalloys. Our calculated elastic constants, bulk modulus, orientation-dependent shear modulus and Young's modulus, as well as the Zener anisotropy factor are all compatible with the measured results of Ni-base model superalloys R1 and the advanced commercial superalloys TMS-26, CMSX-4 at a low temperature. The mechanical properties as a function of the γ' phase volume fraction are calculated by varying the proportion of the γ and γ' phase in the multilayers. Besides, the mechanical properties of two-phase Ni/Ni 3 Al multilayer can be well predicted by the Voigt–Reuss–Hill rule of mixtures. (classical areas of phenomenology)

  2. Machine learning assisted first-principles calculation of multicomponent solid solutions: estimation of interface energy in Ni-based superalloys

    Science.gov (United States)

    Chandran, Mahesh; Lee, S. C.; Shim, Jae-Hyeok

    2018-02-01

    A disordered configuration of atoms in a multicomponent solid solution presents a computational challenge for first-principles calculations using density functional theory (DFT). The challenge is in identifying the few probable (low energy) configurations from a large configurational space before DFT calculation can be performed. The search for these probable configurations is possible if the configurational energy E({\\boldsymbol{σ }}) can be calculated accurately and rapidly (with a negligibly small computational cost). In this paper, we demonstrate such a possibility by constructing a machine learning (ML) model for E({\\boldsymbol{σ }}) trained with DFT-calculated energies. The feature vector for the ML model is formed by concatenating histograms of pair and triplet (only equilateral triangle) correlation functions, {g}(2)(r) and {g}(3)(r,r,r), respectively. These functions are a quantitative ‘fingerprint’ of the spatial arrangement of atoms, familiar in the field of amorphous materials and liquids. The ML model is used to generate an accurate distribution P(E({\\boldsymbol{σ }})) by rapidly spanning a large number of configurations. The P(E) contains full configurational information of the solid solution and can be selectively sampled to choose a few configurations for targeted DFT calculations. This new framework is employed to estimate (100) interface energy ({σ }{{IE}}) between γ and γ \\prime at 700 °C in Alloy 617, a Ni-based superalloy, with composition reduced to five components. The estimated {σ }{{IE}} ≈ 25.95 mJ m-2 is in good agreement with the value inferred by the precipitation model fit to experimental data. The proposed new ML-based ab initio framework can be applied to calculate the parameters and properties of alloys with any number of components, thus widening the reach of first-principles calculation to realistic compositions of industrially relevant materials and alloys.

  3. Hot isostatic pressing of single-crystal nickel-base superalloys: Mechanism of pore closure and effect on Mechanical properties

    Directory of Open Access Journals (Sweden)

    Epishin Alexander I.

    2014-01-01

    Full Text Available Pore annihilation was investigated in the single-crystal nickel-base superalloy CMSX-4. HIP tests at 1288 °C/103 MPa were interrupted at different times, then the specimens were investigated by TEM, metallography and density measurements. The kinetics of pore annihilation was determined. The pore closure mechanism was identified as plastic deformation on the octahedral slip systems. A model describing the kinetics of pore closure has been developed on the base of crystal plasticity and large strain theory. Mechanical tests with the superalloy CMSX-4 and the Ru-containing superalloy VGM4 showed, that HIP significantly increases the fatigue life at low temperatures but has no effect on creep strength.

  4. Effects of Temperature and Pressure of Hot Isostatic Pressing on the Grain Structure of Powder Metallurgy Superalloy.

    Science.gov (United States)

    Tan, Liming; He, Guoai; Liu, Feng; Li, Yunping; Jiang, Liang

    2018-02-24

    The microstructure with homogeneously distributed grains and less prior particle boundary (PPB) precipitates is always desired for powder metallurgy superalloys after hot isostatic pressing (HIPping). In this work, we studied the effects of HIPping parameters, temperature and pressure on the grain structure in PM superalloy FGH96, by means of scanning electron microscope (SEM), electron backscatter diffraction (EBSD), transmission electron microscope (TEM) and Time-of-flight secondary ion spectrometry (ToF-SIMS). It was found that temperature and pressure played different roles in controlling PPB precipitation and grain structure during HIPping, the tendency of grain coarsening under high temperature could be inhibited by increasing HIPping pressure which facilitates the recrystallization. In general, relatively high temperature and pressure of HIPping were preferred to obtain an as-HIPped superalloy FGH96 with diminished PPB precipitation and homogeneously refined grains.

  5. Report on participation of the operational dosimetry division in refurbishment of the RA reactor, Task 3.08/04-13; Podzadatak 3.08/04-13 Izvestaj o ucescu Odseka operativne dozimetrije RZ u remontnim radovima na Reaktoru RA

    Energy Technology Data Exchange (ETDEWEB)

    Ninkovic, M [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    During the refurbishment of the RA reactor, from January to June 1963 the division of operational division had a very important role and comprehensive tasks. To enable safety of the staff it was necessary to provide protection clothes, personnel dosemeters; permanent monitoring of radiation doses; strict control of the procedures for completing the planned maintenance and repair operations to avoid contamination of the personnel and working space. The refurbishment activities described in this report are: removal of fuel from the core; refurbishment of the heavy water system; decontamination of the distillation equipment; repair of the gas system.

  6. Experimental Design for Evaluation of Co-extruded Refractory Metal/Nickel Base Superalloy Joints

    International Nuclear Information System (INIS)

    ME Petrichek

    2005-01-01

    Prior to the restructuring of the Prometheus Program, the NRPCT was tasked with delivering a nuclear space reactor. Potential NRPCT nuclear space reactor designs for the Prometheus Project required dissimilar materials to be in contact with each other while operating at extreme temperatures under irradiation. As a result of the high reactor core temperatures, refractory metals were the primary candidates for many of the reactor structural and cladding components. They included the tantalum-base alloys ASTAR-811C and Ta-10W, the niobium-base alloy FS-85, and the molybdenum base alloys Moly 41-47.5 Rhenium. The refractory metals were to be joined to candidate nickel base alloys such as Haynes 230, Alloy 617, or Nimonic PE 16 either within the core if the nickel-base alloys were ultimately selected to form the outer core barrel, or at a location exterior to the core if the nickel-base alloys were limited to components exterior to the core. To support the need for dissimilar metal joints in the Prometheus Project, a co-extrusion experiment was proposed. There are several potential methods for the formation of dissimilar metal joints, including explosive bonding, friction stir welding, plasma spray, inertia welding, HIP, and co-extrusion. Most of these joining methods are not viable options because they result in the immediate formation of brittle intermetallics. Upon cooling, intermetallics form in the weld fusion zone between the joined metals. Because brittle intermetallics do not form during the initial bonding process associated with HIP, co-extrusion, and explosive bonding, these three joining procedures are preferred for forming dissimilar metal joints. In reference to a Westinghouse Astronuclear Laboratory report done under a NASA sponsored program, joints that were fabricated between similar materials via explosive bonding had strengths that were directly affected by the width of the diffusion barrier. It was determined that the diffusion zone should not exceed

  7. Effect of solution heat treatment on the precipitation behavior and strengthening mechanisms of electron beam smelted Inconel 718 superalloy

    Energy Technology Data Exchange (ETDEWEB)

    You, Xiaogang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Tan, Yi, E-mail: tanyi@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Shi, Shuang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Yang, Jenn-Ming [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095 (United States); Wang, Yinong [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Li, Jiayan; You, Qifan [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China)

    2017-03-24

    Inconel 718 superalloy was fabricated by electron beam smelting (EBS) technique. The effect of solution heat treatment on the precipitation behavior and mechanical properties of EBS 718 superalloys were studied, the strengthening mechanisms were analyzed and related to the mechanical properties. The results indicate that the optimized microstructures can be acquired by means of EBS, which is attributed to the rapid cooling rate of approximately 280 ℃/min. The solution heat treatment shows a great impact on the microstructures, precipitation behavior and mechanical properties of EBS 718 superalloy. The γ'' phase shows an apt to precipitate at relatively lower solution temperatures followed by aging, while the γ' precipitates are prone to precipitate at higher temperatures. When solution treated at 1150 ℃, the γ' precipitates are dispersively distributed in the matrix with size and volume fraction of 8.43 nm and 21.66%, respectively, a Vickers hardness of approximately 489 HV{sub 0.1} is observed for the aged superalloy. The precipitation strengthening effect of EBS 718 superalloy could be elucidated by considering the interaction between the dislocations and γ''/γ' precipitates. The shearing of γ' is resisted by the coherency strengthening and formation of antiphase boundary (APB), which shows equal effect as weakly coupled dislocation (WCD) model. And for γ'', the strengthening effect is much more prominent with the primary strengthening mechanism of ordering. Moreover, it is interestingly found that the strengthening mechanism of stacking fault (SF) shearing coexists with APB shearing, and SF shearing plays a major role in strengthening of EBS 718 superalloy.

  8. Morphology Dependent Flow Stress in Nickel-Based Superalloys in the Multi-Scale Crystal Plasticity Framework

    Directory of Open Access Journals (Sweden)

    Shahriyar Keshavarz

    2017-11-01

    Full Text Available This paper develops a framework to obtain the flow stress of nickel-based superalloys as a function of γ-γ’ morphology. The yield strength is a major factor in the design of these alloys. This work provides additional effects of γ’ morphology in the design scope that has been adopted for the model developed by authors. In general, the two-phase γ-γ’ morphology in nickel-based superalloys can be divided into three variables including γ’ shape, γ’ volume fraction and γ’ size in the sub-grain microstructure. In order to obtain the flow stress, non-Schmid crystal plasticity constitutive models at two length scales are employed and bridged through a homogenized multi-scale framework. The multi-scale framework includes two sub-grain and homogenized grain scales. For the sub-grain scale, a size-dependent, dislocation-density-based finite element model (FEM of the representative volume element (RVE with explicit depiction of the γ-γ’ morphology is developed as a building block for the homogenization. For the next scale, an activation-energy-based crystal plasticity model is developed for the homogenized single crystal of Ni-based superalloys. The constitutive models address the thermo-mechanical behavior of nickel-based superalloys for a large temperature range and include orientation dependencies and tension-compression asymmetry. This homogenized model is used to obtain the morphology dependence on the flow stress in nickel-based superalloys and can significantly expedite crystal plasticity FE simulations in polycrystalline microstructures, as well as higher scale FE models in order to cast and design superalloys.

  9. Market influence on the low carbon energy refurbishment of existing multi-residential buildings

    International Nuclear Information System (INIS)

    Atkinson, Jonathan G.B.; Jackson, Tim; Mullings-Smith, Elizabeth

    2009-01-01

    This paper explores the relationship between the energy market; the political and regulatory context; and energy design decisions for existing multi-residential buildings, to determine what form the energy market landscape would take if tailored to encourage low carbon solutions. The links between market dynamics, Government strategies, and building designs are mapped to understand the steps that achieve carbon reduction from building operation. This is achieved using a model that takes financial and energy components with market and design variables to provide net present cost and annual carbon outputs. The financial component applies discounted cash flow analysis over the building lifespan, with discount rates reflecting contractual characteristics; the carbon component uses Standard Assessment Procedure (SAP) 2005. A scenario approach is adopted to test alternative strategies selected to encourage low carbon solutions in two residential and two office designs. The results show that the forward assumption of energy price escalation is the most influential factor on energy investment, together with the expected differentiation between the escalation of gas and electricity prices. Using this, and other influencing factors, the research reveals trends and strategies that will achieve mainstream application of energy efficiency and microgeneration technologies, and reduce carbon emissions in the existing multi-residential sector.

  10. High-cycle fatigue behavior of Co-based superalloy 9CrCo at elevated temperatures

    OpenAIRE

    Wan, Aoshuang; Xiong, Junjiang; Lyu, Zhiyang; Li, Kuang; Du, Yisen; Chen, Kejiao; Man, Ziyu

    2016-01-01

    A modified model is developed to characterize and evaluate high-cycle fatigue behavior of Co-based superalloy 9CrCo at elevated temperatures by considering the stress ratio effect. The model is informed by the relationship surface between maximum nominal stress, stress ratio and fatigue life. New formulae are derived to deal with the test data for estimating the parameters of the proposed model. Fatigue tests are performed on Co-based superalloy 9CrCo subjected to constant amplitude loading a...

  11. Dendritic coarsening of γ' phase in a directionally solidified superalloy during 24,000 h of exposure at 1173 K

    International Nuclear Information System (INIS)

    Li, H.; Wang, L.; Lou, L.H.

    2010-01-01

    Dendritic coarsening of γ' was investigated in a directionally solidified Ni-base superalloy during exposure at 1173 K for 24,000 h. Chemical homogeneity along different directions and residual internal strain in the experimental superalloy were measured by electronic probe microanalysis (EPMA) and electron back-scattered diffraction (EBSD) technique. It was indicated that the gradient of element distribution was anisotropic and the inner strain between dendrite core and interdendritic regions was different even after 24,000 h of exposure at 1173 K, which influenced the kinetics for the dendrite coarsening of γ' phase.

  12. The effects of ruthenium on the phase stability of fourth generation Ni-base single crystal superalloys

    International Nuclear Information System (INIS)

    Sato, Atsushi; Harada, Hiroshi; Yokokawa, Tadaharu; Murakumo, Takao; Koizumi, Yutaka; Kobayashi, Toshiharu; Imai, Hachiro

    2006-01-01

    The formation of topologically close-packed (TCP) phases in nickel-base single crystal superalloys causes considerable degradation of the mechanical properties. It has recently been found that platinum-group metals can be effective in controlling the precipitation of such phases, and this extent of precipitation control requires further investigation. This study compares Ru-containing and non-Ru-containing single crystal superalloys. Scanning electron microscopy microstructural observations showed that the rate of TCP phase precipitations decreased through Ru addition. Transmission electron microscopy microstructural observations showed that the P phase, one of the TCP phases, was eliminated through the addition of Ru. The occurrence of this phenomenon will be discussed

  13. The effects of Re addition to the nanostructure of a Ni-Cr-Al model superalloy

    International Nuclear Information System (INIS)

    Yoon, K.E.; Seidman, D.N.; Noebe, R.D.

    2004-01-01

    Full text: The refractory elements, such as W, Mo, Ta, and Re, have been at the center of focus since the late 1970s for the development of single-crystal turbine-blades, and they have improved significantly the high-temperature properties of Ni-based superalloys. The optimum mechanical properties and operating temperature of single-crystal blades are achieved by increasing the total amounts of refractory elements. In spite of the improvement of mechanical properties of Ni-based superalloys utilizing the addition of refractory elements, their effects on the microstructure of superalloys are mostly unidentified at the subnano- to nanoscale. Rhenium (2 at.%) was added to a model ternary Ni-8.5 at.% Cr-10 at.% Al superalloy to study its effects on the temporal evolution. The temporal evolution of γ' (L1 2 ) precipitates in a Ni-Cr-AI-Re FCC alloy, aged at 1073 K from 0.25 to 264 h, is investigated by transmission-electron and three-dimensional atom-probe (3DAP) microscopies. The coarsening kinetics of γ' precipitates is investigated by measuring the mean radius, number density of precipitates and matrix supersaturation, and compared with Umantsev-Olson's (UO) coarsening theory for multicomponent alloys. The coarsening experiments do not agree with the time dependencies prediction of UO theory. The cluster-diffusion-coagulation mechanism is involved in coarsening, as well as evaporation-condenzation mechanism, and is suggested to generate discrepancy between the experiments and theory. The addition of Re reduces the lattices parameter misfit between the matrix and precipitates. Therefore, unlike other Ni-based superalloys, this Ni-Cr-AI-Re alloy does not undergo the sphere-to-cube morphological transition and maintains the spheroidal morphology of the γ' precipitates for extended aging times. In addition, the γ' precipitates do not align along [100] direction, even at the longest aging time of 264 h. Contrary to a commercial superalloy Rene N6, significant Re

  14. Thermal evolution behavior of carbides and γ′ precipitates in FGH96 superalloy powder

    International Nuclear Information System (INIS)

    Zhang Lin; Liu Hengsan; He Xinbo; Rafi-ud-din; Qu Xuanhui; Qin Mingli; Li Zhou; Zhang Guoqing

    2012-01-01

    The characteristics of rapidly solidified FGH96 superalloy powder and the thermal evolution behavior of carbides and γ′ precipitates within powder particles were investigated. It was observed that the reduction of powder size and the increase of cooling rate had transformed the solidification morphologies of atomized powder from dendrite in major to cellular structure. The secondary dendritic spacing was measured to be 1.02–2.55 μm and the corresponding cooling rates were estimated to be in the range of 1.4 × 10 4 –4.7 × 10 5 K·s −1 . An increase in the annealing temperature had rendered the phase transformation of carbides evolving from non-equilibrium MC′ carbides to intermediate transition stage of M 23 C 6 carbides, and finally to thermodynamically stable MC carbides. The superfine γ′ precipitates were formed at the dendritic boundaries of rapidly solidified superalloy powder. The coalescence, growth, and homogenization of γ' precipitates occurred with increasing annealing temperature. With decreasing cooling rate from 650 °C·K −1 to 5 °C·K −1 , the morphological development of γ′ precipitates had been shown to proceed from spheroidal to cuboidal and finally to solid state dendrites. Meanwhile, a shift had been observed from dendritic morphology to recrystallized structure between 900 °C and 1050 °C. Moreover, accelerated evolution of carbides and γ' precipitates had been facilitated by the formation of new grain boundaries which provide fast diffusion path for atomic elements. - Highlights: ► Microstructural characteristic of FGH96 superalloy powder was investigated. ► The relation between microstructure, particle size, and cooling rate was studied. ► Thermal evolution behavior of γ′ and carbides in loose FGH96 powder was studied.

  15. Strain-induced γ{sup '}-coarsening during aging of Ni-based superalloys under uniaxial load. Modeling and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mushongera, Leslie T.

    2016-07-28

    Turbine blades which are used in the hot paths of aerospace or industrial gas turbines are usually manufactured as casted single crystalline parts. However, even though grain boundaries are excluded, the degradation behavior of respectively developed single crystal nickel-base superalloys, is still quite complex involving a number of very different microscopic effects. One of these is the diffusion-limited coarsening of the γ{sup '}-precipitates. Long-term aging or creep loading along the <100> crystallographic orientation results in the anisotropic coarsening of the γ{sup '}-precipitates. In the end, the microstructure contains quite large, irregularly shaped precipitates or plate-like precipitates aligned either parallel (P-type rafts) or perpendicular (N-type rafts) to the loading direction. This behavior is detrimental for the properties of these materials since their superior properties emanate from the size, morphology and distribution of the γ{sup '}-precipitates [R. Reed: Cambridge University Press, (2006)]. In order to efficiently design these materials, the phenomenon of coarsening should be known in detail to optimize the materials accurately. On this background, the general objective of this thesis is to develop an integrated computational approach for simulating morphological evolution in single crystal Ni-base superalloys. As a first step towards that aim, a multi-component phase field model coupled to inputs from CALPHAD-type and kinetic databases for the relevant driving forces was developed based on the grand-potential formalism similar to Plapp [Phys. Rev. E, 84: 031601 (2011)]. The thermodynamic formulation of the model was validated by comparisons to ThermoCalc equilibrium calculations and DICTRA sharp-interface simulations. Phase field approaches that allow for anisotropies of the interfacial energy sufficiently high so that the interface develops sharp corners due to missing crystallographic orientations were formulated. This

  16. Formation and Dissolution of gamma ' Precipitates in IN792 Superalloy at Elevated Temperatures

    Czech Academy of Sciences Publication Activity Database

    Strunz, Pavel; Petrenec, Martin; Polák, Jaroslav; Gasser, U.; Farkas, G.

    2016-01-01

    Roč. 6, č. 2 (2016), č. článku 37. ISSN 2075-4701 R&D Projects: GA ČR GB14-36566G; GA MŠk(CZ) LM2011019 EU Projects: European Commission(XE) 283883 - NMI3-II Institutional support: RVO:61389005 ; RVO:68081723 Keywords : metals * high temperature alloys * superalloy * precipitation * neutron scattering * in-situ neutron diffraction * small-angle neutron scattering Subject RIV: BM - Solid Matter Physics ; Magnetism; JL - Materials Fatigue, Friction Mechanics (UFM-A) Impact factor: 1.984, year: 2016

  17. Microstructural investigation of thermally aged nickel-based superalloy 718Plus

    International Nuclear Information System (INIS)

    Whitmore, Lawrence; Ahmadi, Mohammad Reza; Stockinger, Martin; Povoden-Karadeniz, Erwin; Kozeschnik, Ernst; Leitner, Harald

    2014-01-01

    The effects of thermal aging upon the nickel-based 718Plus superalloy are investigated and modelled. Yield strength and micro-hardness measurements are made after solution annealing and after aging at 788 °C for 4 h. In order to explain the differences in strength and hardness, a detailed investigation of the microstructure is performed using transmission electron microscopy. The size and phase fraction of the γ′ precipitates are measured and related to the measured hardness and yield strength using a theoretical model of precipitation strengthening based on the shearing of precipitates in terms of coherency strengthening and the formation of an antiphase boundary

  18. Development of a Ni-based superalloy with cellular structure and interconnected micro porosity

    International Nuclear Information System (INIS)

    Bernabe, A.; Lopez, E.; Gil-Sevillano, J.

    1998-01-01

    A cellular metallic material with interconnected porosity of controlled size of an order of 10 μm has been developed by electrochemical dissolution of tungsten grains in a W-Ni-Fe heavy alloy. The nickel superalloy with sponge structure and high surface/volume ratio can also be processed recycling chips from heavy metal machining (Patent number p9700191, 1997). Applications for the new materials could be found as support for catalysts, high temperature filters for corrosive fluids, burners, etc. (Author) 10 refs

  19. Precipitate Contribution to the Acoustic Nonlinearity in Nickel-Based Superalloy

    Institute of Scientific and Technical Information of China (English)

    Chung-Seok KIM; Cliff J.LISSENDEN

    2009-01-01

    The influence of γ' precipitate on the acoustic nonlinearity is investigated for a nickel-based superalloy,which is subjected to creep deformation.During creep deformation,the cuboidal γ' precipitate is preferentially coarsened in a direction perpendicular to the applied stress axis.The length and shape factor of the γ' precipitate increase with creep time.The increase of relative acoustic nonlinearity with increasing fraction of creep life is discussed in relation to the rafting of γ' precipitate,which is closely related to the scattering and distortion of the acoustic wave.

  20. Mesoscale modeling and simulation of microstructure evolution during dynamic recrystallization of a Ni-based superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fei [University of Nottingham, Department of Mechanical, Materials and Manufacturing Engineering, Nottingham (United Kingdom); Shanghai Jiao Tong University, Institute of Forming Technology and Equipment, Shanghai (China); Cui, Zhenshan [Shanghai Jiao Tong University, Institute of Forming Technology and Equipment, Shanghai (China); Ou, Hengan [University of Nottingham, Department of Mechanical, Materials and Manufacturing Engineering, Nottingham (United Kingdom); Long, Hui [University of Sheffield, Department of Mechanical Engineering, Sheffield (United Kingdom)

    2016-10-15

    Microstructural evolution and plastic flow characteristics of a Ni-based superalloy were investigated using a simulative model that couples the basic metallurgical principle of dynamic recrystallization (DRX) with the two-dimensional (2D) cellular automaton (CA). Variation of dislocation density with local strain of deformation is considered for accurate determination of the microstructural evolution during DRX. The grain topography, the grain size and the recrystallized fraction can be well predicted by using the developed CA model, which enables to the establishment of the relationship between the flow stress, dislocation density, recrystallized fraction volume, recrystallized grain size and the thermomechanical parameters. (orig.)

  1. Synergistic erosion/corrosion of superalloys in PFB coal combustor effluent

    Science.gov (United States)

    Benford, S. M.; Zellars, G. R.; Lowell, C. E.

    1981-01-01

    Two Ni-based superalloys were exposed to the high velocity effluent of a pressurized fluidized bed coal combustor. Targets were 15 cm diameter rotors operating at 40,000 rpm and small flat plate specimens. Above an erosion rate threshold, the targets were eroded to bare metal. The presence of accelerated oxidation at lower erosion rates suggests erosion/corrosion synergism. Various mechanisms which may contribute to the observed oxide growth enhancement include erosive removal of protective oxide layers, oxide and subsurface cracking, and chemical interaction with sulfur in the gas and deposits through damaged surface layers.

  2. Creep-rupture behavior of iron superalloys in high-pressure hydrogen

    Science.gov (United States)

    Bhattacharyya, S.; Peterman, W.

    1984-01-01

    The creep-rupture properties of five iron-base and one cobalt-base high temperature alloys were investigated to assess the feasibility of using the alloys as construction materials in a Stirling engine. The alloys were heat treated and hardness measurements were taken. Typical microstructures of the alloys are shown. The creep-rupture properties of the alloys were determined at 760 and 815 C in 15.0 MPa H2 for 200 to 1000 hours. Plots of rupture life versus stress for the six superalloys are presented along with creep strain-time plots.

  3. Phase transformation and liquid density redistribution during solidification of Ni-based superalloy Inconel 718

    Directory of Open Access Journals (Sweden)

    Wang Ling

    2012-08-01

    Full Text Available The influences of chemical segregation and phase transformation on liquid density variation during solidification of Ni-based supperalloy Inconel 718 were investigated using SEM and EDS. It was found that significant segregation in liquid prompts high Nb phase to precipitate directly from liquid, which results in the redistribution of alloy elements and liquid density in their vicinity. The term “inter-precipitate liquid density” is therefore proposed and this concept should be applied to determine the solidification behavior of superalloy Inconel 718.

  4. Superior creep strength of a nickel-based superalloy produced by selective laser melting

    Energy Technology Data Exchange (ETDEWEB)

    Pröbstle, M., E-mail: martin.proebstle@fau.de [Department of Materials Science & Engineering Institute I, Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstraße 5, D-91058 Erlangen (Germany); Neumeier, S.; Hopfenmüller, J.; Freund, L.P. [Department of Materials Science & Engineering Institute I, Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstraße 5, D-91058 Erlangen (Germany); Niendorf, T. [Institut für Werkstofftechnik (Materials Engineering), Universität Kassel, Mönchebergstr. 3, D-34125 Kassel (Germany); Schwarze, D. [SLM Solutions GmbH, Roggenhorster Straße 9c, D-23556 Lübeck (Germany); Göken, M. [Department of Materials Science & Engineering Institute I, Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstraße 5, D-91058 Erlangen (Germany)

    2016-09-30

    The creep properties of a polycrystalline nickel-based superalloy produced via selective laser melting were investigated in this study. All heat treatment conditions of the additively manufactured material show superior creep strength compared to conventional cast and wrought material. The process leads to a microstructure with fine subgrains. In comparison to conventional wrought material no Niobium rich δ phase is necessary to control the grain size and thus more Niobium is available for precipitation hardening and solid solution strengthening resulting in improved creep strength.

  5. Ir-based refractory superalloys by pulse electric current sintering (PECS) process (II prealloyed powder)

    Science.gov (United States)

    Huang, C.; Yamabe-Mitarai, Y.; Harada, H.

    2002-02-01

    Five prealloyed powder samples prepared from binary Ir-based refractory superalloys were sintered at 1800 °C for 4 h by Pulse Electric Current Sintering (PECS). No metal loss was observed during sintering. The relative densities of the sintered specimens all exceeded 90% T.D. The best one was Ir-13% Hf with the density of 97.82% T.D. Phases detected in sintered samples were in accordance with the phase diagram as expected. Fractured surfaces were observed in two samples (Ir-13% Hf and Ir-15% Zr). Some improvements obtained by using prealloyed powders instead of elemental powders, which were investigated in the previous studies, were presented.

  6. Inhomogeneous dislocation structure in fatigued INCONEL 713 LC superalloy at room and elevated temperatures

    International Nuclear Information System (INIS)

    Petrenec, Martin; Obrtlik, Karel; Polak, Jaroslav

    2005-01-01

    The dislocations arrangement was studied using transmission electron microscopy in specimens of polycrystalline INCONEL 713 LC superalloy cyclically strained up to failure with constant total strain amplitudes at temperatures 300, 773, 973 and 1073 K. Planar dislocation arrangements in the form of bands parallel to the {1 1 1} planes were observed in specimens cycled at all the temperatures. The bands showed up as thin slabs of high dislocation density cutting both the γ channels and γ' precipitates. Ladder-like bands were observed at room temperature

  7. Cyclic plastic response of nickel-based superalloy at room and at elevated temperatures

    International Nuclear Information System (INIS)

    Polak, Jaroslav; Petrenec, Martin; Chlupova, Alice; Tobias, Jiri; Petras, Roman

    2015-01-01

    Nickel-based cast IN 738LC superalloy has been cycled at increasing strain amplitudes at room temperature and at 800 C. Hysteresis loops were analyzed using general statistical theory of the hysteresis loop. Dislocation structures of specimens cycled at these two temperatures were studied. They revealed localization of the cyclic plastic strain in the thin bands which are rich in dislocations. The analysis of the loop shapes yields effective stresses of the matrix and of the precipitates and the probability density function of the critical internal stresses at both temperatures. It allows to find the sources of the high cyclic stress.

  8. Computational Design of Creep-Resistant Alloys and Experimental Validation in Ferritic Superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Liaw, Peter

    2014-12-31

    A new class of ferritic superalloys containing B2-type zones inside parent L21-type precipitates in a disordered solid-solution matrix, also known as a hierarchical-precipitate strengthened ferritic alloy (HPSFA), has been developed for high-temperature structural applications in fossil-energy power plants. These alloys were designed by the addition of the Ti element into a previously-studied NiAl-strengthened ferritic alloy (denoted as FBB8 in this study). In the present research, systematic investigations, including advanced experimental techniques, first-principles calculations, and numerical simulations, have been integrated and conducted to characterize the complex microstructures and excellent creep resistance of HPSFAs. The experimental techniques include transmission-electron microscopy, scanningtransmission- electron microscopy, neutron diffraction, and atom-probe tomography, which provide detailed microstructural information of HPSFAs. Systematic tension/compression creep tests revealed that HPSFAs exhibit the superior creep resistance, compared with the FBB8 and conventional ferritic steels (i.e., the creep rates of HPSFAs are about 4 orders of magnitude slower than the FBB8 and conventional ferritic steels.) First-principles calculations include interfacial free energies, anti-phase boundary (APB) free energies, elastic constants, and impurity diffusivities in Fe. Combined with kinetic Monte- Carlo simulations of interdiffusion coefficients, and the integration of computational thermodynamics and kinetics, these calculations provide great understanding of thermodynamic and mechanical properties of HPSFAs. In addition to the systematic experimental approach and first-principles calculations, a series of numerical tools and algorithms, which assist in the optimization of creep properties of ferritic superalloys, are utilized and developed. These numerical simulation results are compared with the available experimental data and previous first

  9. Investigation of grain competitive growth during directional solidification of single-crystal nickel-based superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xinbao [National Energy R and D Center of Clean and High-Efficiency Fossil-Fired Power Generation Technology, Xi' an Thermal Power Research Institute Co. Ltd., Xi' an (China); Northwestern Polytechnical University, State Key Laboratory of Solidification Processing, Xi' an (China); Liu, Lin; Zhang, Jun [Northwestern Polytechnical University, State Key Laboratory of Solidification Processing, Xi' an (China)

    2015-08-15

    Grain competitive growth of nickel-based single-crystal superalloys during directional solidification was investigated. A detailed characterization of bi-crystals' competitive growth was performed to explore the competitive grain evolution. It was found that high withdrawal rate improved the efficiency of grain competitive growth. The overgrowth rate was increased when the misorientation increased. Four patterns of grain competitive growth with differently oriented dispositions were characterized. The results indicated that the positive branching of the dendrites played a significant role in the competitive growth process. The effect of crystal orientation and heat flow on the competitive growth can be attributed to the blocking mechanism between the adjacent grains. (orig.)

  10. Creep, Fatigue and Environmental Interactions and Their Effect on Crack Growth in Superalloys

    Science.gov (United States)

    Telesman, J.; Gabb, T. P.; Ghosn, L. J.; Smith, T.

    2017-01-01

    Complex interactions of creep/fatigue/environment control dwell fatigue crack growth (DFCG) in superalloys. Crack tip stress relaxation during dwells significantly changes the crack driving force and influence DFCG. Linear Elastic Fracture Mechanics, Kmax, parameter unsuitable for correlating DFCG behavior due to extensive visco-plastic deformation. Magnitude of remaining crack tip axial stresses controls DFCG resistance due to the brittle-intergranular nature of the crack growth process. Proposed a new empirical parameter, Ksrf, which incorporates visco-plastic evolution of the magnitude of remaining crack tip stresses. Previous work performed at 704C, extend the work to 760C.

  11. Products, practices and processes: exploring the innovation potential for low-carbon housing refurbishment among small and medium-sized enterprises (SMEs) in the UK construction industry

    International Nuclear Information System (INIS)

    Killip, Gavin

    2013-01-01

    Scenario-based studies agree that the technical potential for CO 2 emissions reduction from the housing stock is large. This paper explores how a market might be developed for the refurbishment activities assumed in these scenarios, taking the existing market for repair, maintenance and improvement (RMI) as its starting point. Interviews with 16 small and medium-sized enterprises (SMEs) in the construction industry reveal the interdependence of products, practices and processes in housing renovation activities. Conservative practice as well as innovation can be understood as the outcome of multi-lateral influences on firms from other firms, clients, the material buildings and products in their working lives, and from regulations and regulators. Contractors' openness to innovation is contingent on an informal approach to risk assessment, taking account of cost, time efficiency, client demands, and installer confidence in the reliability of the resulting work. The implications of the research are discussed in relation to the need for new practices and processes on refurbishment projects, raising questions for future research on key questions of quality assurance, performance over time, the application of standards, and vocational training. -- Highlights: •Repair, maintenance and improvement works are triggers for low-carbon refurbishment. •Millions of property owners and small firms make for fragmented decision-making. •Actor-Network Theory is used to frame decision-making processes for refurbishment. •Small builders can be innovative if clients allow time and money for experimentation. •Energy policy for existing homes needs to engage with the construction sector

  12. Point Lepreau Refurbishment Project. Programmable digital comparator (PDC) replacement for SDS1 and SDS2 - update 1

    International Nuclear Information System (INIS)

    Fraser, K.G.; Ichiyen, N.M.; Condor, A.E.; Thompson, P.D.

    2005-01-01

    NB Power is tentatively planning to conduct an 18-month maintenance outage of the Point Lepreau Generating Station starting in April 2008. The scope of the outage was determined from the outcome of a two year study (Phase 1) involving a detailed condition assessment of the station which examined issues relating to ageing and obsolescence, along with a detailed review of Safety and Licensing issues associated with extended operation. In order to minimize schedule and regulatory risk for the Refurbishment project, pre-project work was initiated in early 2002. This program is called Phase 2 ESA (Early Start Activities). As part of the Phase 1 assessments it was concluded that replacement of the Programmable Digital Comparators for both shutdown systems was required in order to ensure operation of the plant for a further 25-30 years. Critical tasks were identified related to PDC replacement as part of the Phase 2 ESA program. This paper describes the progress of the Phase 2 ESA program as well as the planned future (Phase 2) work for the PDC replacement for both shutdown systems. (author)

  13. Does demolition or refurbishment of old and inefficient homes help to increase our environmental, social and economic viability?

    International Nuclear Information System (INIS)

    Power, Anne

    2008-01-01

    The issue of whether to demolish or refurbish older housing has been debated for over a century. It has been an active policy area since the late 1880s, when the Government first authorised the statutory demolition of insanitary slums. In the 1960s, revulsion at the scale of 'demolition blight' and new building caused a rethink, leading to a major reinvestment in inner city neighbourhoods of older housing. In the past 5 years, debate on demolition and new building has been intensified by the Government's Sustainable Communities Plan of 2003, with its proposals for large-scale clearance and building. Environmental arguments about renovating the existing stock have gained increasing prominence as people have sought to defend their communities from demolition. The evidence on whether demolition would reduce the amount of greenhouse gases we emit into the atmosphere is unclear and disputed. This paper summarises the evidence and arguments, and attempts to clarify the most realistic, achievable route to major reductions in energy use in homes

  14. Optimal and Sustainable Plant Refurbishment in Historical Buildings: A Study of an Ancient Monastery Converted into a Showroom in Florence

    Directory of Open Access Journals (Sweden)

    Carla Balocco

    2013-04-01

    Full Text Available The aim of this research is to study the possibility and sustainability of retrofit and refurbishment design solutions on historical buildings converted to different uses and often clashing with their original purpose and architectural features. The building studied is an ancient monastery located in the historical center of Florence (Italy. Today the original cloister is covered over by a single glazed pitched roof and used as a fashion showroom. Our proposed solution concerns a reversible and sustainable plant design integrated with an active transparent building casing. The existing glazed pitched roof was reconsidered and re-designed as part of the existing heating, ventilation and air conditioning (HVAC plant system, based on the functioning of an active thermal buffer to control the high heat flow rates and external thermal loads due to solar radiation. Hourly whole building energy analysis was carried out to check the effectiveness and energy sustainability of our proposed solution. Results obtained showed, from the historical-architectural, energy and environmental points of view, its sustainability due to the building-plant system integration and interaction with its location, the external climatic conditions and defined expected uses, in particular with reference to indoor thermal comfort.

  15. Does demolition or refurbishment of old and inefficient homes help to increase our environmental, social and economic viability?

    Energy Technology Data Exchange (ETDEWEB)

    Power, Anne [London School of Economics, Houghton Street, London WC2A 2AE (United Kingdom); Sustainable Development Commission, Room 101, 55 Whitehall, c/o 3-8 Whitehall Place, London SW1A 2HH (United Kingdom)

    2008-12-15

    The issue of whether to demolish or refurbish older housing has been debated for over a century. It has been an active policy area since the late 1880s, when the Government first authorised the statutory demolition of insanitary slums. In the 1960s, revulsion at the scale of 'demolition blight' and new building caused a rethink, leading to a major reinvestment in inner city neighbourhoods of older housing. In the past 5 years, debate on demolition and new building has been intensified by the Government's Sustainable Communities Plan of 2003, with its proposals for large-scale clearance and building. Environmental arguments about renovating the existing stock have gained increasing prominence as people have sought to defend their communities from demolition. The evidence on whether demolition would reduce the amount of greenhouse gases we emit into the atmosphere is unclear and disputed. This paper summarises the evidence and arguments, and attempts to clarify the most realistic, achievable route to major reductions in energy use in homes. The arguments that apply to housing also apply to most other buildings and therefore to the overall built environment, which accounts for half of all carbon emissions. Three main sources of evidence have helped in the development of this paper, but there are many other studies we draw on in the discussion.

  16. Influence of composition on precipitation behavior and stress rupture properties in INCONEL RTM740 series superalloys

    Science.gov (United States)

    Casias, Andrea M.

    Increasing demands for energy efficiency and reduction in CO2 emissions have led to the development of advanced ultra-supercritical (AUSC) boilers. These boilers operate at temperatures of 760 °C and pressures of 35 MPa, providing efficiencies close to 50 pct. However, austenitic stainless steels typically used in boiler applications do not have sufficient creep or oxidation resistance. For this reason, nickel (Ni)-based superalloys, such as IN740, have been identified as potential materials for AUSC boiler tube components. However, IN740 is susceptible to heat-affected-zone liquation cracking in the base metal of heavy section weldments. To improve weldability, IN740H was developed. However, IN740H has lower stress rupture ductility compared to IN740. For this reason, two IN740H modifications have been produced by lowering carbon content and increasing boron content. In this study, IN740, IN740H, and the two modified IN740H alloys (modified 1 and 2) were produced with equiaxed grain sizes of 90 ìm (alloys IN740, IN740H, and IN740H modified 1 alloys) and 112 µm (IN740H modified 2 alloy). An aging study was performed at 800 °C on all alloys for 1, 3, 10, and 30 hours to assess precipitation behavior. Stress rupture tests were performed at 760 °C with the goal of attaining stress levels that would yield rupture at 1000 hours. The percent reduction in area was measured after failure as a measure of creep ductility. Light optical, scanning electron, and transmission electron microscopy were used in conjunction with X-ray diffraction to examine precipitation behavior of annealed, aged, and stress rupture tested samples. The amount and type of precipitation that occurred during aging prior to stress rupture testing or in-situ during stress rupture testing influenced damage development, stress rupture life, and ductility. In terms of stress rupture life, IN740H modified 2 performed the best followed by IN740H modified 1 and IN740, which performed similarly, and IN740

  17. Refurbishment of primary coolant pump stuffing boxes for RAPS-1,2

    International Nuclear Information System (INIS)

    Rshikesan, P.B.; Shirolkar, K.M.; Ahmad, S.N.

    2006-01-01

    Primary coolant pumps (PCPs) are the most critical equipment in PHWR and stuffing box is one of the critical parts of the PCP. The stuffing box houses the mechanical seals, radial bearings, throttle bushings and stationary part of wearing ring. During overhauling of PCPs it was observed that the cracks are developing on the inside face of the stuffing box and at the bolt holes where the lower bearing housing is fixed. Since consequence of failure of stuffing box will be a break in primary system boundary a detailed investigation was carried out to find out cause of failure. An immediate procurement of these from OEM (Original Equipment Manufacturer) was not feasible and indigenous procurement of such a large and precision-machined PCP component would have called for extensive development work. Under the circumstances, the only immediate option left was to repair and re-use these failed stuffing boxes. However, repair of these stuffing boxes was considered to be very difficult job as weld repair could cause distortion and any other option was not found suitable. Since the industry was not geared up to produce such components, a decision to carry out a heavy weld build up after removing the cracks up to root, was taken after considering various other options. Major weld repair and subsequent machining was carried out successfully on four stuffing boxes and subsequently these have been put in to service. The paper covers the investigations done, various options considered, how the weld repairs were carried out and the salient features of the indigenous development taken up. (author)

  18. Evaluation of powder metallurgical processing routes for multi-component niobium silicide-based high-temperature alloys

    Energy Technology Data Exchange (ETDEWEB)

    Seemueller, Hans Christoph Maximilian

    2016-03-22

    Niobium silicide-based composites are potential candidates to replace nickel-base superalloys for turbine applications. The goal of this work was to evaluate the feasibility and differences in ensuing properties of various powder metallurgical processing techniques that are capable of manufacturing net-shape turbine components. Two routes for powder production, mechanical alloying and gas atomization were combined with compaction via hot isostatic pressing and powder injection molding.

  19. Handbook of International alloy Compositions and Designations. Volume II. Superalloys

    Science.gov (United States)

    1978-12-01

    Aubert et Duval, 92200 Neuilly-sur-Seine, Paris, France C-0180 August Dreckshage Eisen und Stahl, 4800 Bielefeld, West Germany C-0021 Avesta Jernverks...Aktiebolag, 774 01 Avesta , Sweden B C-0087 Babcock & Wilcox, Beaver Falls, Pennsylvania 15010 C-0126 Bergische Stahl-lndustrie, (BSD 5630 Remscheid...C-0033) C-0021 Avesta Jernverks Aktiebolag, 774 01 Avesta , Sweden C-0022 Howmet Turbine Components Corporation, (Div. of PUG), Muskegon, Michigan

  20. Oxidation behavior of HVOF sprayed Ni-5Al coatings deposited on Ni- and Fe-based superalloys under cyclic condition

    International Nuclear Information System (INIS)

    Mahesh, R.A.; Jayaganthan, R.; Prakash, S.

    2008-01-01

    Ni-5Al coating was obtained on three superalloy substrates viz. Superni 76, Superni 750 and Superfer 800 using high velocity oxy-fuel (HVOF) spray process. Oxidation studies were carried out on both bare and coated superalloy substrates in air at 900 deg. C for 100 cycles. The weight change was measured at the end of each cycle and observed that the weight gain was high in Superni 750 alloy when compared to Superni 76 and Superfer 800. A nearly parabolic oxidation behavior was observed for Ni-5Al coated Superni 750 and Superfer 800 alloys but a Ni-5Al coated Superni 76 substrate showed a slight deviation. The scale was analysed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) and electron probe microanalysis (EPMA). The coating increased the oxidation resistance for all the alloy substrates at 900 deg. C. Among the three-coated superalloys, Superfer 800 substrate has shown the best resistance to oxidation. The protective nature of the Ni-5Al coated superalloys was due to the formation of protective oxide scales such as NiO, Al 2 O 3 and Cr 2 O 3

  1. Modeling Long-term Creep Performance for Welded Nickel-base Superalloy Structures for Power Generation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Chen [GE Global Research, NIskayuna, NY (United States); Gupta, Vipul [GE Global Research, NIskayuna, NY (United States); Huang, Shenyan [GE Global Research, NIskayuna, NY (United States); Soare, Monica [GE Global Research, NIskayuna, NY (United States); Zhao, Pengyang [GE Global Research, NIskayuna, NY (United States); Wang, Yunzhi [GE Global Research, NIskayuna, NY (United States)

    2017-02-28

    The goal of this project is to model long-term creep performance for nickel-base superalloy weldments in high temperature power generation systems. The project uses physics-based modeling methodologies and algorithms for predicting alloy properties in heterogeneous material structures. The modeling methodology will be demonstrated on a gas turbine combustor liner weldment of Haynes 282 precipitate-strengthened nickel-base superalloy. The major developments are: (1) microstructure-property relationships under creep conditions and microstructure characterization (2) modeling inhomogeneous microstructure in superalloy weld (3) modeling mesoscale plastic deformation in superalloy weld and (4) a constitutive creep model that accounts for weld and base metal microstructure and their long term evolution. The developed modeling technology is aimed to provide a more efficient and accurate assessment of a material’s long-term performance compared with current testing and extrapolation methods. This modeling technology will also accelerate development and qualification of new materials in advanced power generation systems. This document is a final technical report for the project, covering efforts conducted from October 2014 to December 2016.

  2. Microstructural characterization of a modified 706-type Ni-Fe superalloy by small-angle neutron scattering and electron microscopy

    Czech Academy of Sciences Publication Activity Database

    Del Genovese, D.; Strunz, Pavel; Mukherji, D.; Gilles, R.; Rösler, J.

    36A, - (2005), s. 3439-3450 ISSN 1073-5623 Institutional research plan: CEZ:AV0Z10480505 Keywords : superalloys * small-angle neutron scattering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.232, year: 2005

  3. Superalloys. Volume 2. 1977-February 1978 (citations from the NTIS data base). Report for 1977--Feb 78

    International Nuclear Information System (INIS)

    Smith, M.F.

    1978-03-01

    Federally-funded research on cobalt- and nickel-based superalloys is cited. Casting and powder metallurgy of these alloys are covered. Properties such as heat resistance, corrosion resistance, microstructure, fracture, and creep are described. The use of these materials in nuclear reactors, gas turbine parts, and high-temperature equipment is a major part of this compilation

  4. Transformed model fitting. A straightforward approach to evaluation of anisotropic SANS from nickel-base single-crystal superalloys

    International Nuclear Information System (INIS)

    Strunz, P.

    1999-01-01

    Schematic description of a special evaluation procedure for data treatment of anisotropic Small-Angle Neutron Scattering (SANS) is presented. The use of the discussed procedure is demonstrated on a data taken from investigation of precipitation in single-crystal nickel-base superalloys. (author)

  5. Influence of dwell times on the thermomechanical fatigue behavior of a directionally solidified Ni-base superalloy

    Czech Academy of Sciences Publication Activity Database

    Guth, S.; Petráš, Roman; Škorík, Viktor; Kruml, Tomáš; Man, Jiří; Lang, K. H.; Polák, Jaroslav

    2015-01-01

    Roč. 80, NOV (2015), s. 426-433 ISSN 0142-1123 R&D Projects: GA MŠk(CZ) EE2.3.30.0063 Institutional support: RVO:68081723 Keywords : Nickel base superalloy * Thermomechanical fatigue * Dwell time * Lifetime behavior * Damage mechanisms Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.162, year: 2015

  6. Enhancing the Oxidation Performance of Wrought Ni-Base Superalloy by Minor Additions of Active Elements

    Science.gov (United States)

    Tawancy, H. M.

    2016-12-01

    We show that the oxidation performance of Cr2O3-forming superalloy based upon the Ni-Cr-W system is significantly improved by the presence of minor concentrations of La, Si and Mn, which outweigh the detrimental effect of high W concentration in the alloy. Although Cr2O3 is known to transform into volatile CrO3 at temperatures ≥950 °C, the respective protection is extended to temperatures reaching 1150 °C, which has also been correlated with the beneficial effects of La, Si and Mn. During high-temperature oxidation, an inner protective La- and Si-modified layer of α-Cr2O3 in contact with the superalloy substrate is developed and shielded by an outermost layer of MnCr2O4. The distribution of La and Si in the inner oxide layer has been characterized down to the scale of transmission electron microscopy, and the possible mechanisms underlying their beneficial effects are elucidated.

  7. Role of tantalum in the hot corrosion of a Ni-base single crystal superalloy

    International Nuclear Information System (INIS)

    Chang, J.X.; Wang, D.; Liu, T.; Zhang, G.; Lou, L.H.; Zhang, J.

    2015-01-01

    Highlights: • Ta is beneficial to hot corrosion resistance. • Ta promoted the formation of a new type sulphide TaS 2 . • Thermodynamic factors affect the constituent of sulphide layer. • Ta can substitute Cr for sulphur catcher in hot corrosion. • The result provides new perspective in hot corrosion resistant superalloys design. - Abstract: Hot corrosion behaviour of a Ni-base single crystal superalloy with low Cr, Ti and high Ta contents in molten sodium sulphate (Na 2 SO 4 ) at 900 °C in static air was investigated using the “deposit recoat” method. The corrosion scale was composed of an outer NiO layer, an inner Al 2 O 3 -dominant oxide network layer and a (CrS x(1.000

  8. Experimental investigation on the spiral trepanning of K24 superalloy with femtosecond laser

    Science.gov (United States)

    Wang, Maolu; Yang, Lijun; Zhang, Shuai; Wang, Yang

    2018-05-01

    Film cooling holes are crucial for improving the performance of the aviation engine. In the paper, the processing of the film cooling holes on K24 superalloy by femtosecond laser is investigated. By comparing the three different drilling methods, the spiral trepanning method is chosen, and all the drilling experiments are carried out in this way. The experimental results show that the drilling of femtosecond laser pulses has distinct merits against that of the traditional long pulse laser, which can realize the "cold" processing with less recasting layer and less crack. The influence of each process parameter on roundness and taper, which are the important parameters to measure the quality of holes, is analyzed in detail, and the method to decrease it is proposed. To further reduce the recasting layer, the processing quality of the inner wall of the micro hole is investigated by scanning electron microscopy (SEM) equipped with energy disperse spectroscopy (EDS), the mechanism of the femtosecond laser interaction with K24 superalloy is further revealed. The investigation to the film hole machining by femtosecond laser has important practical significance.

  9. Fatigue Resistance of the Grain Size Transition Zone in a Dual Microstructure Superalloy Disk

    Science.gov (United States)

    Gabb, T. P.; Kantzos, P. T.; Telesman, J.; Gayda, J.; Sudbrack, C. K.; Palsa, B. S.

    2010-01-01

    Mechanical property requirements vary with location in nickel-based superalloy disks. To maximize the associated mechanical properties, heat treatment methods have been developed for producing tailored microstructures. In this study, a specialized heat treatment method was applied to produce varying grain microstructures from the bore to the rim portions of a powder metallurgy processed nickel-based superalloy disk. The bore of the contoured disk consisted of fine grains to maximize strength and fatigue resistance at lower temperatures. The rim microstructure of the disk consisted of coarse grains for maximum resistance to creep and dwell crack growth at high temperatures up to 704 C. However, the fatigue resistance of the grain size transition zone was unclear, and needed to be evaluated. This zone was located as a band in the disk web between the bore and rim. Specimens were extracted parallel and transverse to the transition zone, and multiple fatigue tests were performed at 427 and 704 C. Mean fatigue lives were lower at 427 C than for 704 C. Specimen failures often initiated at relatively large grains, which failed on crystallographic facets. Grain size distributions were characterized in the specimens, and related to the grains initiating failures as well as location within the transition zone. Fatigue life decreased with increasing maximum grain size. Correspondingly, mean fatigue resistance of the transition zone was slightly higher than that of the rim, but lower than that of the bore. The scatter in limited tests of replicates was comparable for all transition zone locations examined.

  10. High Temperature Degradation of Powder-processed Ni-based Superalloy

    Directory of Open Access Journals (Sweden)

    Natália Luptáková

    2015-05-01

    Full Text Available The aim of present work is to study the high temperature degradation of the powder-processed polycrystalline superalloy Ni-15Cr-18Co-4Al-3.5Ti-5Mo. This superalloy has been applied as material for grips of a creep machine. The material was exposed at 1100 °C for about 10 days at 10 MPa stress. During the creep test occurred unacceptable creep deformation of grips as well as severe surface oxidation with scales peeling off. Three types of the microstructure were observed in the studied alloy: (i unexposed state; (ii heat treated (annealing - 10 min/1200 °C and (iii after using as a part of the equipment of the creep machine during the creep test. It is shown that the microstructure degradation resulting from the revealed γ´ phase fcc Ni3(Al,Ti particles preferentially created at the grain boundaries of the samples after performing creep tests affects mechanical properties of the alloy and represents a significant contribution to all degradation processes affecting performance and service life of the creep machine grips. Based on investigation and obtained results, the given material is not recommended to be used for grips of creep machine at temperatures above 1000 °C.

  11. Solidification behaviors of a single-crystal superalloy under lateral constraints

    International Nuclear Information System (INIS)

    Zhuangqi Hu; Huaming Wang

    1993-01-01

    The effect of lateral constraints ahead of solidification interface on the solidification behaviors of a newly developed hot corrosion resistant single-crystal nickel-base superalloy was investigated under commercial single-crystal production conditions. The lateral constraints or section variations ahead of solidification front were found to have drastic influences both on the modes of solidification and the profiles of solute segregation. As lateral constraints were imposed ahead of the directionally solidifying interface, the solidification microstructure of the single-crystal superalloy changed suddenly, through a γ/γ' eutectic-free zone which is characterized by an extremely-fine and highly-developed dendrite network, from the original well-branched dendritic structure to a fine cellular-dendrite or regular cell structure, accompanying which the primary arm spacing, the severity of segregation and the amount of microporosity decreased remarkably. The newly formed cellular dendrite or cell structure transforms always gradually to the initial coarse dendrite structure as the lateral constraint is finally released whether gradually or sharply. Moreover, an abnormal porosity zone was readily observed in the initial section beneath and away from the eutectic-free zone. The solidification microstructural changes were attributed to the drastic dynamical changes in local solidification cooling conditions and in momentum transport during solidification due to the presence of lateral constraint

  12. High-temperature γ (FCC/γ′ (L12 Co-Al-W based superalloys

    Directory of Open Access Journals (Sweden)

    Knop Matthias

    2014-01-01

    Full Text Available Interim results from the development of a polycrystalline Co-Al-W based superalloy are presented. Cr has been added to provide oxidation resistance and Ni has then been added to widen and stabilise the γ′ phase field. The alloy presented has a solvus of 1010 °C and a density of 8.7 g cm−3. The room temperature flow stress is over 1000 MPa and this reduces dramatically above 800 °C. The flow stress anomaly is observed. A microstructure with both ∼ 50 nm γ′ produced on cooling and larger 100–200 nm γ′ can be obtained. Isothermal oxidation at 800 °C in air for 200 h gave a mass gain of 0.96 mg cm−2. After hot deformation in the 650–850 °C temperature range, both anti phase boundaries (APBs and stacking faults could be observed. An APB energy of 71 mJ m−2 was measured, which is comparable to that found in commercial nickel superalloys.

  13. Cyclic Oxidation and Hot Corrosion Behavior of Nickel-Iron-Based Superalloy

    Science.gov (United States)

    Chellaganesh, D.; Adam Khan, M.; Winowlin Jappes, J. T.; Sathiyanarayanan, S.

    2018-01-01

    The high temperature oxidation and hot corrosion behavior of nickel-iron-based superalloy are studied at 900 ° and 1000 °C. The significant role of alloying elements with respect to the exposed medium is studied in detail. The mass change per unit area was catastrophic for the samples exposed at 1000 °C and gradual increase in mass change was observed at 900 °C for both the environments. The exposed samples were further investigated with SEM, EDS and XRD analysis to study the metallurgical characteristics. The surface morphology has expressed the in situ nature of the alloy and its affinity toward the environment. The EDS and XRD analysis has evidently proved the presence of protective oxides formation on prolonged exposure at elevated temperature. The predominant oxide formed during the exposure at high temperature has a major contribution toward the protection of the samples. The nickel-iron-based superalloy is less prone to oxidation and hot corrosion when compared to the existing alloy in gas turbine engine simulating marine environment.

  14. Characterization and Modeling of Microstructure Development in Nickel-base Superalloy Welds

    Energy Technology Data Exchange (ETDEWEB)

    Babu, S.S.; David, S.A.; Miller, M.K.; Vitek, J.M.

    1999-11-01

    Welding is important for economical reuse and reclamation of used and failed nickel-base superalloy blades, respectively [1]. Solidification and solid state decomposition of {gamma} (Face Centered Cubic, FCC) phase into {gamma}{prime} (L1{sub 2}-ordered) phase control the properties of these welds. In previous publications, the microstructure development in electron beam welds of PWA-1480 alloy [2] and laser beam welds of CMSX-4 alloy [3] were presented. These results showed that the weld cracking in these alloys were associated with low melting point eutectic at the dendrite boundaries [1,2]. The eutectic-{gamma}{prime} precipitation was reduced at rapid weld cooling rates and the partitioning between {gamma}-{gamma}{prime} phase was found to be far from equilibrium conditions [3,4]. This observation was related to diffusional growth of {gamma}{prime} precipitate into {gamma} phase. Subsequent to the above work, the precipitation characteristics of {gamma}{prime} phase from {gamma} phase were evaluated during continuous cooling conditions [5]. The results show that the number density of {gamma} precipitates increased with an increase in cooling rate. However, the details of this decomposition and also the fine-scale elemental partitioning characteristics between {gamma}-{gamma}{prime} were not investigated. In this paper, the precipitation characteristics of {gamma}{prime} from {gamma} during continuous cooling conditions were investigated with transmission electron microscopy, and atom probe field ion microscopy. In addition, thermodynamic and kinetic models were used to describe microstructure development in Ni-base superalloy welds.

  15. Study on Plastic Deformation Characteristics of Shot Peening of Ni-Based Superalloy GH4079

    Science.gov (United States)

    Zhong, L. Q.; Liang, Y. L.; Hu, H.

    2017-09-01

    In this paper, the X-ray stress diffractometer, surface roughness tester, field emission scanning electron microscope(SEM), dynamic ultra-small microhardness tester were used to measure the surface residual stress and roughness, topography and surface hardness changes of GH4079 superalloy, which was processed by metallographic grinding, turning, metallographic grinding +shot peening and turning + shot peening. Analysized the effects of shot peening parameters on shot peening plastic deformation features; and the effects of the surface state before shot peening on shot peening plastic deformation characteristics. Results show that: the surface residual compressive stress, surface roughness and surface hardness of GH4079 superalloy were increased by shot peening, in addition, the increment of the surface residual compressive stress, surface roughness and surface hardness induced by shot peening increased with increasing shot peening intensity, shot peening time, shot peening pressure and shot hardness, but harden layer depth was not affected considerably. The more plastic deformation degree of before shot peening surface state, the less increment of the surface residual compressive stress, surface roughness and surface hardness induced by shot peening.

  16. The Formation and Evolution of Shear Bands in Plane Strain Compressed Nickel-Base Superalloy

    Directory of Open Access Journals (Sweden)

    Bin Tang

    2018-02-01

    Full Text Available The formation and evolution of shear bands in Inconel 718 nickel-base superalloy under plane strain compression was investigated in the present work. It is found that the propagation of shear bands under plane strain compression is more intense in comparison with conventional uniaxial compression. The morphology of shear bands was identified to generally fall into two categories: in “S” shape at severe conditions (low temperatures and high strain rates and “X” shape at mild conditions (high temperatures and low strain rates. However, uniform deformation at the mesoscale without shear bands was also obtained by compressing at 1050 °C/0.001 s−1. By using the finite element method (FEM, the formation mechanism of the shear bands in the present study was explored for the special deformation mode of plane strain compression. Furthermore, the effect of processing parameters, i.e., strain rate and temperature, on the morphology and evolution of shear bands was discussed following a phenomenological approach. The plane strain compression attempt in the present work yields important information for processing parameters optimization and failure prediction under plane strain loading conditions of the Inconel 718 superalloy.

  17. Synergistic effect of rhenium and ruthenium in nickel-based single-crystal superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Yu, X.X. [Department of Physics, Tsinghua University, Beijing 100084 (China); Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Wang, C.Y., E-mail: cywang@mail.tsinghua.edu.cn [Department of Physics, Tsinghua University, Beijing 100084 (China); Central Iron and Steel Research Institute, Beijing 100081 (China); Zhang, X.N. [Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124 (China); Yan, P. [Central Iron and Steel Research Institute, Beijing 100081 (China); Zhang, Z., E-mail: zezhang@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

    2014-01-05

    Highlights: • Re and Ru synergistic effects in nickel-based superalloys are investigated. • The Al site occupation of Re atom in the γ′ phase is observed directly. • The addition of Ru results in the repartitioning of Re to γ phase. -- Abstract: The microstructures of ternary Ni–Al–Re and quaternary Ni–Al–Re–Ru single-crystal alloys were investigated at atomic and electronic levels to clarify the synergistic effect of Re and Ru in nickel-based single-crystal superalloys. In the Ni–Al–Re alloy, it was directly observed that Re atom occupied the Al site of γ′ phase. In the Ni–Al–Re–Ru alloy, the mechanisms of Re repartition between γ and γ′ phases were proposed. In the dendritic cores, high concentrations of Re exceeded the solubility limit of γ′ phase and partitioned to γ phase, which led to the homogenization. In the interdendritic regions, Ru resulted in the repartitioning of Re to γ phase which was proved by transmission electron microscopy and first-principles calculations.

  18. Control of microstructure and mechanical properties of laser solid formed Inconel 718 superalloy by electromagnetic stirring

    Science.gov (United States)

    Liu, Fencheng; Cheng, Hongmao; Yu, Xiaobin; Yang, Guang; Huang, Chunping; Lin, Xin; Chen, Jing

    2018-02-01

    The coarse columnar grains and special interface in laser solid formed (LSFed) Inconel 718 superalloy workpieces seriously affect their mechanical properties. To improve the microstructure and mechanical properties of LSFed Inconel 718 superalloy, electromagnetic stirring (EMS) was introduced to alter the solidification process of the molten pool during LSF. The results show that EMS could not completely eliminate the epitaxially growing columnar grains, however, the strong convection of liquid metals can effectively influence the solid-liquid interface growing mode. The segregation of alloying elements on the front of solid-liquid interface is inhibited and the degree of constitutional supercooling decreases correspondingly. Comparing the microstructures of samples formed under different process parameters, the size and amount of the γ+Laves eutectic phases formed in interdendritic area decrease along with the increasing magnetic field intensity, resulting in more uniformly distributed alloying elements. The residual stress distribution is proved to be more uniform, which is beneficial to the grain refinement after recrystallilzaiton. Mechanical properties testing results show an improvement of 100 MPa in tensile strength and 22% in elongation was obtained after EMS was used. The high cycle fatigue properties at room temperature was also improved from 4.09 × 104 cycles to 8.21 × 104 cycles for the as-deposited samples, and from 5.45 × 104 cycles to 12.73 × 104 cycles for the heat treated samples respectively.

  19. Very High Cycle Fatigue of Ni-Based Single-Crystal Superalloys at High Temperature

    Science.gov (United States)

    Cervellon, A.; Cormier, J.; Mauget, F.; Hervier, Z.; Nadot, Y.

    2018-05-01

    Very high cycle fatigue (VHCF) properties at high temperature of Ni-based single-crystal (SX) superalloys and of a directionally solidified (DS) superalloy have been investigated at 20 kHz and a temperature of 1000 °C. Under fully reversed conditions (R = - 1), no noticeable difference in VHCF lifetimes between all investigated alloys has been observed. Internal casting pores size is the main VHCF lifetime-controlling factor whatever the chemical composition of the alloys. Other types of microstructural defects (eutectics, carbides), if present, may act as stress concentration sites when the number of cycles exceed 109 cycles or when porosity is absent by applying a prior hot isostatic pressing treatment. For longer tests (> 30 hours), oxidation also controls the main crack initiation sites leading to a mode I crack initiation from oxidized layer. Under such conditions, alloy's resistance to oxidation has a prominent role in controlling the VHCF. When creep damage is present at high ratios (R ≥ 0.8), creep resistance of SX/DS alloys governs VHCF lifetime. Under such high mean stress conditions, SX alloys developed to retard the initiation and creep propagation of mode I micro-cracks from pores have better VHCF lifetimes.

  20. Spray forming and mechanical properties of a new type powder metallurgy superalloy

    International Nuclear Information System (INIS)

    Jia Chong-Lin; Ge Chang-Chun; Xia Min; Gu Tian-Fu

    2015-01-01

    The deposited billet of a new type powder metallurgy (PM) superalloy FGH4095M for use in turbine disk manufacturing has been fabricated using spray forming technology. The metallurgical quality of the deposited billet was analyzed in terms of density, texture, and grain size. Comparative research was done on the microstructure and mechanical properties between the flat disk preform prepared with hot isostatic pressing (HIP) and the same alloy forgings prepared with HIP followed by isothermal forging (IF). The results show that the density of the spray-formed and nitrogen-atomized deposit billet is above 99% of the theoretical density, indicating a compact structure. The grains are uniform and fine. The billet has weak texture with a random distribution in the spray deposition direction and perpendicular to the direction of deposition. A part of atomizing nitrogen exists in the preform in the form of carbonitride. Nitrogen-induced microporosity causes the density reduction of the preform. Compared with the process of HIP+IF, the superalloy FGH4095M after HIP has better mechanical properties at both room temperature and high temperature. The sizes of the γ′ phase are finer in microstructure of the preform after HIP in comparison with the forgings after HIP+IF. This work shows that SF+HIP is a viable processing route for FGH4095M as a turbine-disk material. (paper)