Download or read book Fission fusion Correlations for Swelling and Microstructure in Stainless Steels written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The initial irradiated structural materials data base for fusion applications will be developed in fission reactors. Hence, this data may need to be adjusted using physically-based procedures to represent behavior in fusion environments, viz. - fission-fusion correlations. Such correlation should reflect a sound mechanistic understanding, and be verified in facilities which most closely simulate fusion conditions. In this paper we review the effects of only one of a number of potentially significant damage variables, the helium to displacement per atom ratio, on microstructural evolution in austenitic stainless steels. Dual-ion and helium preinjection data are analyzed to provide mechanistic guidance; these results appear to be qualitatively consistent with a more detailed comparison made between fast (EBR-II) and mixed (HFIR) spectrum neutron data for a single heat of 20% cold-worked 316 stainless steel. These two fission environments bound fusion (He/dpa ratios. A model calibrated to the fission reactor data is used to extrapolate to fusion conditions. Both the theory and broad empirical observation suggest that helium to dpa ratios have both a qualitative and quantitative influence on microstructural evolution; and that the very high and low ratios found in HFIR and EBR-II may not result in behavior which brackets intermediate fusion conditions.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Composite Model of Microstructural Evolution in Austenitic Stainless Steel Under Fast Neutron Irradiation written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A rate-theory-based model has been developed which includes the simultaneous evolution of the dislocation and cavity components of the microstructure of irradiated austenitic stainless steels. Previous work has generally focused on developing models for void swelling while neglecting the time dependence of the dislocation structure. These models have broadened our understanding of the physical processes that give rise to swelling, e.g., the role of helium and void formation from critically-sized bubbles. That work has also demonstrated some predictive capability by successful calibration to fit the results of fast reactor swelling data. However, considerable uncertainty about the values of key parameters in these models limits their usefulness as predictive tools. Hence the use of such models to extrapolate fission reactor swelling data to fusion reactor conditions is compromised.
Download or read book Fusion Energy Update written by and published by . This book was released on 1980 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Composite Model of Microstructural Evolution in Austenitic Stainless Steel Under Fast Neutron Irradiation written by GR. Odette and published by . This book was released on 1987 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: A rate-theory-based model has been developed which includes the simultaneous evolution of the dislocation and cavity components of the microstructure of irradiated austenitic stainless steels. Previous work has generally focused on developing models for void swelling while neglecting the time dependence of the dislocation structure. These models have broadened our understanding of the physical processes that give rise to swelling, for example, the role of helium and void formation from critically-sized bubbles. That work has also demonstrated some predictive capability by successful calibration to fit the results of fast reactor swelling data. However, considerable uncertainty about the values of key parameters in these models limits their usefulness as predictive tools. Hence, the use of such models to extrapolate fission reactor swelling data to fusion reactor conditions is compromised.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1982 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1989 with total page 890 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindeks written by and published by . This book was released on 1986 with total page 1574 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impact of Swelling on Fusion Reactor First Wall Lifetime written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The impact of swelling in 20% cold-worked Type 316 stainless steel on first wall lifetime is assessed. Three separate predictive swelling correlations, two of which are empirically derived from available fission reactor data and one which is largely based upon a theoretical model, have been used. The swelling equations have been incorporated into a materials lifetime code that examines the temperature-stress-strain-radiation effects history of fusion components. The code has been applied to the INTOR, DEMO, and STARFIRE first wall designs.
Download or read book The Effect of Helium on Swelling in Stainless Steel written by GR. Odette and published by . This book was released on 1982 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction of displacement damage and transmutant helium is thought to be an important factor in the evolution of cavity microstructures. A plausible sequence of events involves the growth of bubbles to a critical size or critical number of helium atoms. Above this critical size, determined by the local point defect fluxes, the cavities grow rapidly as voids. Cavities growing at matrix-precipitate interfaces convert to voids at a lower helium content than matrix cavities due to surface energy and other effects. Such precipitate-associated voids are the major source of swelling in austenitic stainless steels in fast reactors. Because of several competing mechanisms, the increased helium to displacement (He/dpa) ratios characteristic of fusion and mixed-spectrum fission reactors can lead to either significant increases or decreases in net cavity swelling when compared with fast reactors. Cavity density is believed to be a critical factor and it is increased at higher He/dpa ratios. We use a calibrated rate theory swelling model to examine the combined effect of cavity density and helium generation rate; the influence of precipitates is also modeled. At very high cavity densities, which may be produced at high He/dpa ratios, a bifurcation in the swelling path is observed: precipitate-associated voids give way to matrix bubbles and reduced swelling. At lower cavity densities swelling is enhanced at higher helium levels, primarily due to reduced incubation exposures. Most significantly, the theory predicts nonmonotonic swelling behavior as a function of the He/dpa ratio. These results have important implications with respect to use of fast spectrum (low He/dpa ratio) and mixed-spectrum (high He/dpa ratio) fission reactor data to predict swelling in fusion spectra at intermediate He/dpa ratios. Indeed, the model suggests the peak swelling is near the fusion He/dpa ratio for some austenitic stainless steels.
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration. Technical Information Center and published by . This book was released on 1976 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1993 with total page 1216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Energy Research Abstracts written by and published by . This book was released on 1977 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975-12 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Microstructure on Swelling and Tensile Properties of Neutron Irradiated Types 316 and 405 Stainless Steels written by KR. Garr and published by . This book was released on 1973 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small-sheet tensile samples of Types 316 and 405 stainless steels were encapsulated together and irradiated in EBR-II at about 400 C (752 F) to a total fluence of 3.3 x 1022 n/cm2 with 2.3 x 1022 n/cm2 fast (E>0.1 MeV). A variety of microstructures was produced in each alloy prior to irradiation. In Type 316 stainless steel, swelling increased with the amount of carbide precipitation prior to irradiation, implying that carbon in solution impedes void formation. Cold-working 25 percent suppressed void formation. No swelling was observed in Type 405 stainless steel. Irradiation caused an increase in the yield and tensile strengths, and a decrease in ductility in all cases except the cold-worked Type 316 stainless steel. These latter samples showed a decrease in yield and tensile strengths and an increase in ductility due to the reversion of ? martensite to austenite.
