Download or read book Relationship Between Swelling and Irradiation Creep in Cold worked PCA Stainless Steel Irradiated to 78 Dpa at 00 C written by and published by . This book was released on 1993 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The eighth and final irradiation segment for pressurized tubes constructed from the fusion Prime Candidate Alloy (PCA) has been completed in FFTF. At 178 dpa and -400°C, the irradiation creep of 20% cold-worked PCA has become dominated by the {open_quotes}creep disappearance{close_quotes} phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels employed in this test. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however, requiring the use of several non-traditional techniques to extract the creep coefficients. No failures occurred in these tubes, even though the swelling ranged from -20 to -40%.
Download or read book Relationship Between Swelling and Irradiation Creep in Cold worked PCA Stainless Steel Irradiated to approximately 178 Dpa at approximately 400 degrees C written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The eighth and final irradiation segment for pressurized tubes constructed from the fusion Prime Candidate Alloy (PCA) has been completed in FFTF. At 178 dpa and [approximately]400[degrees]C, the irradiation creep of 20% cold-worked PCA has become dominated by the [open-quotes]creep disappearance[close-quotes] phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels employed in this test. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however, requiring the use of several non-traditional techniques to extract the creep coefficients. No failures occurred in these tubes, even though the swelling ranged from [approximately]20 to [approximately]40%.
Download or read book The Relationship Between Swelling and Irradiation Creep in 20 Cold Worked 316 Stainless Steel written by MB. Toloczko and published by . This book was released on 2000 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The relationship between swelling and irradiation creep was investigated using eight sets of pressurized tubes, representing two heats of 20% cold-worked 316 stainless steel irradiated at either 550°C, 575°C, 600°C, and 670°C in the FFTF-MOTA to doses of 79-84 dpa. After reaching these exposures, the tubes were clearly being affected by the "creep cessation" phenomenon. Many of the tubes had already reached the previously observed maximum strain rate of 0.33%/dpa characteristic of creep cessation. Fortuitous failure of fourteen tubes allowed the separation of creep and swelling strains in the creep cessation regime, showing that the maximum strain rate limitation was reached long before the maximum swelling rate of 1%/dpa was reached. Thus, the creep contribution was declining as the swelling rate increased throughout the irradiation.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1983 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Comprehensive Nuclear Materials written by Todd R Allen and published by Elsevier. This book was released on 2011-05-12 with total page 3552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Nuclear Materials, Five Volume Set discusses the major classes of materials suitable for usage in nuclear fission, fusion reactors and high power accelerators, and for diverse functions in fuels, cladding, moderator and control materials, structural, functional, and waste materials. The work addresses the full panorama of contemporary international research in nuclear materials, from Actinides to Zirconium alloys, from the worlds' leading scientists and engineers. Critically reviews the major classes and functions of materials, supporting the selection, assessment, validation and engineering of materials in extreme nuclear environment Fully integrated with F-elements.net, a proprietary database containing useful cross-referenced property data on the lanthanides and actinides Details contemporary developments in numerical simulation, modelling, experimentation, and computational analysis, for effective implementation in labs and plants
Download or read book Irradiation Creep and Swelling of AISI 316 to Exposures of 130 Dpa at 385 to 400 C written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The creep and swelling of AISI 316 stainless steel have been studied at 385 to 400°C in EBR-II to doses of 130 dpa. Most creep capsules were operated at constant stress and temperature but mid-life changes in these variable were also made. This paper concentrates on the behavior of the 20% cold-worked condition but five other conditions were also studied. Swelling at less than or equal to00°C was found to lose the sensitivity to stress exhibited at higher temperatures while the creep rate was found to retain linear dependencies on both stress and swelling rate. The creep coefficients extracted at 400°C agree with those found in other experiments conducted at higher temperatures. In the temperature range of less than or equal to400°C, swelling is in the recombination-dominated regime and the swelling rate falls strongly away from the approx. 1%/dpa rate observed at higher temperatures. These lower rates of creep and swelling, coupled with the attainment of high damage levels without failure, encourage the use of AISI 316 in the construction of water-cooled fusion first walls operating at temperatures below 400°C. 23 refs., 8 figs.
Download or read book Influence of Cold Work Level on the Irradiation Creep and Creep Rupture of Titanium modified Austenitic Stainless Steels written by and published by . This book was released on 1992 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: A titanium-modified austenitic type stainless steel was tested at three cold work levels to determine its creep and creep rupture properties under both thermal aging and neutron irradiation conditions. Both the thermal and irradiation creep behavior exhibit a complex non-monotonic relationship with cold work level that reflects the competition between a number of stress-sensitive and temperature-dependent microstructural processes. Increasing the degree of cold work to 30% form the conventional 20% level was detrimental to its performance, especially for applications above 550°C. The 20% cold work level is preferable to the 10% level, in terms of both in- reactor creep rapture response and initial strength.
Download or read book Irradiation Creep in Type 316 Stainless Steel and US PCA with Fusion Reactor He written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Irradiation creep was investigated in type 316 stainless steel (316 SS) and US Fusion Program PCA using a tailored spectrum of the Oak Ridge Research Reactor in order to achieve a He/dpa value characteristic of a fusion reactor first wall. Pressurized tubes with stresses of 20 to 470 MPa were irradiated at temperatures of 330, 400, 500, and 600°C. It was found that irradiation creep was independent of temperature in this range and varied linearly with stress at low stresses, but the stress exponent increased to 1.3 and 1.8 for 316 SS and PCA, respectively, at higher stresses. Specimens of PCA irradiated in the ORR and having helium levels up to 200 appM experienced a 3 to 10 times higher creep rate than similar specimens irradiated in the FFTF and having helium levels below 20 appM. The higher creep rates are attributed to either a lower flux or the presence of helium. A mechanism involving interstitial helium-enhanced climb is proposed. 17 refs.
Download or read book Irradiation induced Creep in 316 and 304L Stainless Steels Fast Neutrons written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent results are presented from the in-reactor creep experiments that are being conducted by Argonne National Laboratory. The experiments consist of four subassemblies that contain helium-pressurized as well as unstressed capsules of 316 and 304L stainless steels in several metallurgical conditions. Experiments are being irradiated in row 7 of the EBR-II sodium-cooled fast breeder reactor. Three of the subassemblies are being irradiated at temperatures near 400°C, and the fourth subassembly is being irradiated at a temperature of 550°C. Creep and swelling strains were determined by profilometer measurements on the full length of the capsules after each irradiation cycle. The accumulated neutron dose on the 304L capsules at 385°C was 45 dpa; on the 316 capsules at 400°C, 40 dpa; and on the 316 capsules at 550°C, 25 dpa. It was found that the in-reactor creep rates were linearly dependent on hoop stress, with the exception being capsules of 316 stainless steel that had been given long-term carbide aging treatment and then irradiated at 550°C. Those capsules exhibited much higher creep and swelling rates than their unaged counterparts. For the metallurgical conditions where significant swelling was observed (solution-annealed 304L and aged 316 stainless steels), it was found that the in-reactor creep rates were readily fit to a model that related the creep rates to accumulated swelling. Additionally, it was found that the stress-normalized creep rate for 20%-cold-worked 316 stainless steel at a temperature of 550°C was 1.6 times that observed at 400°C.
Download or read book Reanalysis of Swelling and Irradiation Creep Data on 316 Type Stainless Steels Irradiated in the FFTF and Ph nix Fast Reactors written by MB. Toloczko and published by . This book was released on 2000 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: In comparing results of irradiation creep experiments conducted by researchers in France and those by researchers at Pacific Northwest National Laboratory in the United States, quite different values for the creep-swelling coupling coefficient were reported. The differing coefficients complicated the understanding of the growing data base on irradiation creep. However, upon careful consideration, the French and US results showed key differences in experimental technique and analysis. The French and US irradiation creep experiments were conducted with several important differences that were initially thought to be of little consequence. One difference was related to whether stress-free swelling or stress-enhanced swelling was measured and used in calculating the creep strains. Inspection of irradiation creep results published by the French also showed their technique for extracting the creep-swelling coupling coefficient was different than that used by the present authors. In an effort to better understand the origin of the differing creep coefficients, data from the French and US experiments was reanalyzed taking into account these differences. In performing this reanalysis, completely consistent results were obtained.
Download or read book Effect of the Degree of Cold Work on the Irradiation Induced Swelling of Type 316 Stainless Steel written by KD. Challenger and published by . This book was released on 1975 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of the degree of cold work, as measured by X-ray line broadening techniques, on the irradiation-induced swelling of Type 316 stainless steel has been studied using 5-MeV nickel ions as the bombarding species. The level of cold work is expressed in terms of nonuniform lattice strain, ?. A critical value of ? exists below which swelling is a strongly decreasing function of ?, and above which a saturation of the effect occurs such that further increases in ? have very little influence on the swelling behavior. The critical value of ? increases with increasing temperature and ion dose. The implications of these results on the design of an liquid metal fast breeder reactor fuel rod are discussed.
Download or read book Effects of Prior Stress History on Irradiation Induced Creep written by GL. Wire and published by . This book was released on 1976 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this paper is to report the results of an experimental study to determine the effects of previous irradiation history on the fast-flux neutron irradiation creep behavior of 20 percent cold-worked Type 316 stainless steel for liquid metal fast breeder reactor (LMFBR) application. Previous irradiation creep experiments have involved monitoring the irradiation creep strain of specimens held at constant stress while irradiated at approximately constant temperature and flux. Under these conditions, the irradiation creep rates have been observed to vary with neutron exposure. Application of these "creep curve" data to design and analysis of reactor core structural materials requires some knowledge of how the creep rate at a given point in time depends upon the previous stress history.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1982-09 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Irradiation Creep Due to SIPA Under Cascade Damage Conditions written by FA. Garner and published by . This book was released on 1994 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper derives the relationships between void swelling and irradiation creep due to SIPA and SIG under cascade damage conditions in an irradiated pressurized tube. It is found that at low swelling rates irradiation creep is a major contribution to the total diametral strain rate of the tube, whereas at high swelling rate the creep becomes a minor contribution. The anisotropy of the corresponding dislocation structure is also predicted to decline as the swelling rate increases. The theoretical predictions are found to agree very well with experimental results.
Download or read book Influence of Cold Work on the Creep rupture Properties of Type 347 Stainless Steel written by Warren Daniel Rowland and published by . This book was released on 1953 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Theoretical Model of Accelerated Irradiation Creep at Low Temperatures by Transient Interstitial Absorption written by ML. Grossbeck and published by . This book was released on 1992 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: A theoretical model has been developed using the reaction rate theory of radiation effects to explain experimental results that showed higher than expected values of irradiation creep at low temperatures in the Oak Ridge research reactor (ORR). The customary assumption that the point-defect concentrations are at steady state was not made; rather, the time dependence of the vacancy and interstitial concentrations and the creep rate were explicitly calculated. For temperatures below about 100 to 200°C, the time required for the vacancy concentration to reach steady state exceeds the duration of the experiment. For example, if materials parameters typical of austenitic stainless steel are used, the calculated vacancy transient dose at 100°C is about 100 dpa. At 550°C this transient is over by 10-8 dpa. During the time that the vacancy population remains lower than its steady-state value, dislocation climb is increased since defects of primarily one type (interstitials) are being absorbed. Using the time-dependent point-defect concentrations, the dislocation climb velocity has been calculated as a function of time and a climb-enabled glide creep model has been invoked. The extended transient time for the vacancies leads to high creep rates at low temperatures. In agreement with experimental observations, a minimum in the temperature dependence of creep is predicted at a temperature between 50 and 350°C. The temperature at which the minimum occurs decreases as the irradiation dose increases. Predicted values of creep at 8 dpa are in good agreement with the results of the ORR-MFE-67/7J experiment.
Download or read book Initial Results of Swelling and Irradiation Creep Interaction Testing written by JP. Foster and published by . This book was released on 1982 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: An EBR-II irradiation test, designated as WSA-60, was established to provide swelling and irradiation creep interaction data when these two effects interact simultaneously in opposition. This type of behavior occurs under irradiation in cylindrical tubing containing an internal heat source and external heat sink. The WSA-60 test consists of encapsulated fuel pins wherein the capsules comprise the test samples.
