Influence of Hydride "blisters" on the Failure of Zircaloy-4 Under Equal Biaxial Tension PDF Download

Author: Andrew L. Glendening
Publisher:
ISBN:
Category :
Languages : en
Pages : 84

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Author: A. Glendening
Publisher:
ISBN:
Category : Biaxial deformation
Languages : en
Pages : 18

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The fracture behavior of unirradiated Zircaloy-4 containing either solid hydride blisters or hydrided rims has been examined for the contrasting conditions of equal-biaxial and plane-strain tensile deformation at three temperatures (25°, 300°, and 375°C). Cold-worked and stress-relieved Zircaloy-4 sheet containing hydride blisters shows nearly identical failure strains in equal-biaxial and plane-strain tensile deformation for a wide range of blister or rim depths. In all cases, failure strains decrease rapidly with increasing hydride blister or rim thickness, especially in the ?100 ?m range. Test temperature has a significant effect on ductility with failure strains at 300° and 375°C being much greater than at room temperature. The results indicate that the ductility of material containing hydride rims/blisters greater than ? 30-40 ?m deep is limited by crack growth, which occurs in a mode I manner at 25°C but in a mixed mode I/II manner at ?300°C (and at higher failure strain levels).

Author: Cyril A. Migdal
Publisher: ASTM International
ISBN: 0803134932
Category : Antioxidants
Languages : en
Pages : 929

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This work presents papers from a December 2005 symposium held in Norfolk, Virginia, and sponsored by ASTM Committee D2 on Petroleum Products and Lubricants and its Subcommittees D02.09 on Oxidation and D02.C0 on Turbine Oils. Contributors include equipment manufacturers, end users, lubricant producers, lubricant additive suppliers, test equipment manufacturers, and standard test method developers. They share information on industry trends, evolving technologies, and changing equipment designs and operating conditions, with a focus on how these factors impact oxidation. Some topics covered include turbine oil performance limits, a new form of the rotating pressure vessel oxidation test, and degradation mechanisms leading to sludge and varnish in modern turbine oil formulations. B&w photos are included. There is no subject index. Migdal is affiliated with Chemtura Corporation.

Author: Kuan-Che Lan
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 182

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Hydride formation is one of the main degradation mechanisms of zirconium alloys in hydrogen-rich environments. When sufficient hydrogen is present, zirconium- hydride precipitates can be formed. Cracking of the brittle hydrides near a crack tip can initiate the growth of a crack leading to the premature failure of the material. Hydride formation is believed to be enhanced by the presence of residual or applied stresses. Therefore, the increase in the stress field ahead of a crack tip may promote precipitation of additional hydrides. In order to verify these phenomena, the effect of internal stresses on the zirconium-hydride-precipitate formation, and in turn, the influence of the hydrides on the subsequest intergranular strain evolution in a hexagonal-close-packed zircaloy-4 alloy were investigated, using neutron and x-ray diffraction. First, the evolution of intergranular strains in a zircaloy-4 was investigated in-situ, using neutron diffraction, to understand the deformation behavior at the microscopic length scale. A series of uniaxial tensile loads up to 500 MPa was applied to a round-bar tensile specimen in the as-received condition and the intergranular (hkl-specific) strains, parallel and perpendicular to the loading direction, were studied. The results provide a fundamental understanding of the anisotropic elastic-plastic deformation of the zirconium alloy under applied stresses. Then the hydride formation was examined by conducting qualitative phase mapping across the diameter of two tensile specimens charged with hydrogen gas for 1/2 hour and 1 hour, respectively. It was observed that the zirconium hydrides ([delta]-ZrH2) form a layer, in a ring shape, near the surface with a thickness of approximately 400 [mu]m. The hydrogen-charging effects on intergranular strains were investigated and compared to the as-received specimen. Second, spatially-resolved internal-strain mapping was performed on a fatigue pre-cracked compact-tension (CT) specimen using in-situ neutron diffraction under applied loads of 667 and d4,444 newtons, to determine the in-plane (parallel to the loading direction) and through-thickness (perpendicular to the loading direction) lattice-strain profiles around the crack tip. An increase in elastic lattice strains near the crack tip was observed with the increase in the applied stresses. The effect of hydrogen charging was also investigated on CT specimens electrochemically charged with hydrogen. X-ray diffraction results clearly showed the presence of zircomium hydrides on the surfaces of the specimen.

Author: Gerry D. Moan
Publisher: ASTM International
ISBN: 0803128959
Category : Nuclear fuel claddings
Languages : en
Pages : 891

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Annotation The 41 papers of this proceedings volume were first presented at the 13th symposium on Zirconium in the Nuclear Industry held in Annecy, France in June of 2001. Many of the papers are devoted to material related issues, corrosion and hydriding behavior, in-reactor studies, and the behavior and properties of Zr alloys used in storing spent fuel. Some papers report on studies of second phase particles, irradiation creep and growth, and material performance during loss of coolant and reactivity initiated accidents. Annotation copyrighted by Book News, Inc., Portland, OR.

Author: A. W. Sommer
Publisher:
ISBN:
Category : Hydrogen
Languages : en
Pages : 44

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Author: Alan Russell
Publisher: John Wiley & Sons
ISBN: 0471708534
Category : Technology & Engineering
Languages : en
Pages : 440

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This junior/senior textbook presents fundamental concepts ofstructure property relations and a description of how theseconcpets apply to every metallic element except iron. Part One of the book describes general concepts of crystalstructure, microstructure and related factors on the mechanical,thermal, magnetic and electronic properties of nonferrous metals,intermetallic compounds and metal matrix composites. Part Two discusses all the nonferrous metallic elements from twoperspectives: First it explains how the concepts presented in PartOne define the properties of a particular metallic element and itsalloys. Second is a description of the major engineering uses ofeach metal. This section features sidebar pieces describingparticular physical property oddities, engineering applications andcase studies. An Instructor's Manual presenting detailed solutionsto all the problems in the book is available from the Wileyeditorial department. An Instructor's Manual presenting detailed solutions to all theproblems in the book is available from the Wiley editorialdepartment.

Author: K L Murty
Publisher: Elsevier
ISBN: 0857097458
Category : Technology & Engineering
Languages : en
Pages : 441

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Light water reactors (LWRs) are the predominant class of nuclear power reactors in operation today; however, ageing and degradation can influence both their performance and lifetime. Knowledge of these factors is therefore critical to safe, continuous operation. Materials ageing and degradation in light water reactors provides a comprehensive guide to prevalent deterioration mechanisms, and the approaches used to handle their effects.Part one introduces fundamental ageing issues and degradation mechanisms. Beginning with an overview of ageing and degradation issues in LWRs, the book goes on to discuss corrosion in pressurized water reactors and creep deformation of materials in LWRs. Part two then considers materials' ageing and degradation in specific LWR components. Applications of zirconium alloys in LWRs are discussed, along with the ageing of electric cables. Materials management strategies for LWRs are then the focus of part three. Materials management strategies for pressurized water reactors and VVER reactors are considered before the book concludes with a discussion of materials-related problems faced by LWR operators and corresponding research needs.With its distinguished editor and international team of expert contributors, Materials ageing and degradation in light water reactors is an authoritative review for anyone requiring an understanding of the performance and durability of this type of nuclear power plant, including plant operators and managers, nuclear metallurgists, governmental and regulatory safety bodies, and researchers, scientists and academics working in this area. - Introduces the fundamental ageing issues and degradation mechanisms associated with this class of nuclear power reactors - Considers materials ageing and degradation in specific light water reactor components, including properties, performance and inspection - Chapters also focus on material management strategies

Author: Manfred P. Puls
Publisher: Springer Science & Business Media
ISBN: 1447141954
Category : Science
Languages : en
Pages : 475

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By drawing together the current theoretical and experimental understanding of the phenomena of delayed hydride cracking (DHC) in zirconium alloys, The Effect of Hydrogen and Hydrides on the Integrity of Zirconium Alloy Components: Delayed Hydride Cracking provides a detailed explanation focusing on the properties of hydrogen and hydrides in these alloys. Whilst the emphasis lies on zirconium alloys, the combination of both the empirical and mechanistic approaches creates a solid understanding that can also be applied to other hydride forming metals. This up-to-date reference focuses on documented research surrounding DHC, including current methodologies for design and assessment of the results of periodic in-service inspections of pressure tubes in nuclear reactors. Emphasis is placed on showing how our understanding of DHC is supported by progress in general understanding of such broad fields as the study of hysteresis associated with first order phase transformations, phase relationships in coherent crystalline metallic solids, the physics of point and line defects, diffusion of substitutional and interstitial atoms in crystalline solids, and continuum fracture and solid mechanics. Furthermore, an account of current methodologies is given illustrating how such understanding of hydrogen, hydrides and DHC in zirconium alloys underpins these methodologies for assessments of real life cases in the Canadian nuclear industry. The all-encompassing approach makes The Effect of Hydrogen and Hydrides on the Integrity of Zirconium Alloy Component: Delayed Hydride Cracking an ideal reference source for students, researchers and industry professionals alike.