Download or read book The Effect of Helium on Microstructural Evolution and Mechanical Properties of Fe Cr Ni Alloys as Determined in a Spectral Tailoring Experiment written by and published by . This book was released on 1991 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fe-15Cr-XNi alloys irradiated at both low (0.66 to 1.2) and very high (27 to 58) helium/dpa levels exhibit significantly different levels of strengthening due to an unprecedented refinement of cavity microstructure at the very high helium levels. When compounded with the nickel dependence of helium generation, the cavity distribution for some irradiation conditions and alloy compositions can be driven below the critical radius for bubble-to-void conversion, leading to a delay in swelling. The critical radius also appears to be dependent on the nickel level. The refinement may not have resulted from the high helium levels alone, however but also may have been influenced by differences in displacement rate and temperature history in the two experiments.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1993 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1994-03 with total page 332 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 1993 with total page 1206 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 1218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fusion Energy Update written by and published by . This book was released on 1979 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1992 with total page 1138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992-07 with total page 1320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Isotopic Tailoring with 59Ni to Study the Effect of Helium on Microstructural Evolution and Mechanical Properties of Neutron irradiated Fe Cr Ni Alloys written by and published by . This book was released on 1992 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tensile testing on three model Fe-Cr-Ni alloys removed from four discharges of the 59Ni isotopic doping experiment in FFTF-MOTA indicates that helium/dpa ratios typical of fusion reactors do not produce changes in the yield strength or elongation that are significantly different from those at much lower helium generation rates. It also appears that tensile properties approach a saturation level that is dependent only on the final irradiation temperature, but not prior temperature history or thermomechanical starting condition. The saturation in mechanical properties reflects a similar saturation in microstructure that is independent of starting condition. The successful conduct of an isotopic doping experiment was found to require post-irradiation measurement of the helium levels in order to compensate for uncertainties in the cross sections for burn-out and burn-in of 59Ni and for uncertainties in neutron flux and spectra in the vicinity of the edge of the core.

Download or read book Isotopic Tailoring with Sup 59 Ni to Study the Effect of Helium on Microstructural Evolution and Mechanical Properties of Neutron irradiated Fe Cr Ni Alloys written by and published by . This book was released on 1992 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tensile testing on three model Fe-Cr-Ni alloys removed from four discharges of the 59Ni isotopic doping experiment in FFTF-MOTA indicates that helium/dpa ratios typical of fusion reactors do not produce changes in the yield strength or elongation that are significantly different from those at much lower helium generation rates. It also appears that tensile properties approach a saturation level that is dependent only on the final irradiation temperature, but not prior temperature history or thermomechanical starting condition. The saturation in mechanical properties reflects a similar saturation in microstructure that is independent of starting condition. The successful conduct of an isotopic doping experiment was found to require post-irradiation measurement of the helium levels in order to compensate for uncertainties in the cross sections for burn-out and burn-in of 59Ni and for uncertainties in neutron flux and spectra in the vicinity of the edge of the core.

Download or read book The Influence of Helium on Mechanical Properties of Model Austenitic Alloys Determined Using Sup 59 Ni Isotopic Tailoring and Fast Reactor Irradiation written by and published by . This book was released on 1990 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this effort is to study the separate and synergistic effects of helium and other important variables on the evolution of microstructure and macroscopic properties during irradiation of structural metals. The alloys employed in this study were nominally Fe-15Cr-25Ni, Fe-15Cr-25Ni-0.04P and Fe-15Cr-45Ni (wt %) in both the cold worked and annealed conditions. Tensile testing and microscopy continue on specimens removed from the first, second and third discharges of the 59Ni isotopic doping experiment. The results to date indicate that helium/dpa ratios typical of fusion reactors (4 to 19 appm/dpa) do not lead to significant changes in the yield strength of model Fe-Cr-Ni alloys. Measurements of helium generated in undoped specimens from the second and third discharges show that the helium/dpa ratio increases during irradiation in FFTF due to the production of 59Ni. In specimens doped with 59Ni prior to irradiation, the helium/dpa ratio can increase, decrease or remain the same during the second irradiation interval. This behavior occurs because the cross sections for the production and burnout of 59Ni are very sensitive to core location and the nature of neighboring components. 14 refs., 5 figs., 3 tabs.

Download or read book Effects of Radiation on Materials written by Arvind S. Kumar and published by ASTM International. This book was released on 1994 with total page 1319 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Review written by Oak Ridge National Laboratory and published by . This book was released on 1985 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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Download or read book Microstructural Evolution of Neutron Irradiated Fe Cr Ni Alloys at 495 C in Response to Changes in the Helium DPA Ratio written by FA. Garner and published by . This book was released on 1990 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of three Fe-15Cr-XNi alloys in both annealed and cold worked conditions was irradiated in the fast flux test facility (FFTF) at 495°C to 14 dpa. The experiment was developed to determine the separate and synergistic effects of nickel and phosphorus content, cold work, and helium/dpa ratio. This experiment was conducted without introducing variations in displacement rate, a variable known to strongly influence microstructural evolution. Each alloy condition was irradiated in two variants, one with natural nickel and one enhanced with the 59Ni isotope. The latter variant produces helium/dpa ratios typical of fusion reactor spectra while the former yields a much lower level of helium. The results show that helium alters the microstructural evolution somewhat at 495°C, but its effect is relatively small compared to the influences of the other variables studied. Increases in starting dislocation density, nickel content, or phosphorus level all retard swelling temporarily while higher rates of helium generation usually, but not always, accelerate swelling. Phosphorus addition of 0.04 wt% not only decreased swelling but led to refinement of dislocation loop microstructure and stabilization of dislocation networks created by cold working. Phosphide precipitates did not form at this temperature and dose level.

Download or read book Helium Generation Rates in Isotopically Tailored Fe Cr Ni Alloys Irradiated in FFTF written by and published by . This book was released on 1991 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three Fe-Cr-Ni alloys have been doped with 0.4% 59Ni for side-by-side irradiations of doped and undoped materials in order to determine the effects of fusion-relevant levels of helium production on microstructural development and mechanical properties. The alloys were irradiated in three successive cycles of the Materials Open Test Assembly (MOTA) located in the Fast Flux Test Facility (FFTF). Following irradiation, helium levels were measured by isotope dilution mass spectrometry. The highest level of helium achieved in doped alloys was 172 appm at 9.1 dpa for a helium(appm)-to-dpa ratio of 18.9. The overall pattern of predicted helium generation rates in doped and undoped alloys is in good agreement with the helium measurements.

Download or read book The Influence of Helium on Mechanical Properties of Model Austenitic Alloys Determined Using 59Ni Isotopic Tailoring and Fast Reactor Irradiation written by and published by . This book was released on 1991 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tensile testing on model Fe-Cr-Ni alloys removed from four discharges of the 59Ni isotopic doping experiment in FFTF indicates that helium/dpa ratios typical of fusion reactors do not produce changes in the yield strength or elongation that are significantly different from those at much lower helium generation rates. It also appears that tensile properties approach a saturation level that is dependent only on the final irradiation temperature, but not prior temperature history or thermomechanical starting condition. 14 refs., 4 figs., 1 tab.