Microstructural Evolution of Neutron Irradiated Fe-Cr-Ni Alloys at 495°C in Response to Changes in the Helium/DPA Ratio PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Microstructural Evolution of Neutron Irradiated Fe-Cr-Ni Alloys at 495°C in Response to Changes in the Helium/DPA Ratio PDF full book. Access full book title Microstructural Evolution of Neutron Irradiated Fe-Cr-Ni Alloys at 495°C in Response to Changes in the Helium/DPA Ratio by FA. Garner. Download full books in PDF and EPUB format.
Author: FA. Garner Publisher: ISBN: Category : Cold work Languages : en Pages : 13
Book Description
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.
Author: FA. Garner Publisher: ISBN: Category : Cold work Languages : en Pages : 13
Book Description
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.
Author: H. Kawanishi Publisher: ISBN: Category : Cold work Languages : en Pages : 11
Book Description
Three ternary austenitic alloys(Fe-15Cr-25Ni, Fe-15Cr-25Ni-0.04P, Fe-15Cr-45Ni in both annealed and cold worked conditions) were irradiated at 465°C to 0.15, 0.28, and 0.42 dpa at above core position in the Fast Flux Test Facility utilizing the Materials Open Test Assembly to study the separate and synergistic effects of He/dpa ratio, phosphorus addition, nickel content and cold work level on microstructural evolution and hardening. The helium/dpa ratio was varied by isotopic doping with 59Ni to enhance the production rate of helium. The helium production rate was evaluated to be 62 appm He/dpa in the 59Ni-doped specimens and 0.26 appm He/dpa in the undoped specimens.
Author: Publisher: ISBN: Category : Languages : en Pages : 21
Book Description
A series of Fe-Cr-Ni ternary alloy, were irradiated to 12-14 dpa in the Oak Ridge Research Reactor (ORR). In this experiment, most of helium atoms were produced by the 58Ni(n, [gamma])59Ni(n, [alpha])56Fe sequential reaction, and, therefore, the helium generation rate was almost proportional to the nickel content, ranging from 27 to 58 appm He/dpa in 20 to 45 wt.% Ni alloys. Irradiation temperatures were 330, 400, 500 and 600°C, and the specimen variables were the nickel level, the chromium level and cold working. The high levels helium, combined with details of the temperature history, were found to have dominated microstructural development, sometimes overwhelming and even reversing the action of a given material variable. Microscopy examination showed that there was an unprecedented refinement of cavity microstructure at all temperatures, which accounts for the substantial alterations in both swelling and mechanical properties observed in earlier studies.
Author: H. Takahashi Publisher: ISBN: Category : Depletion Languages : en Pages : 10
Book Description
Microstructural changes and solute segregation in austenitic Fe-Cr-Mn-Ni alloys have been studied after neutron irradiation to 25 dpa (maximum) in FFTF/MOTA. Voids were nucleated in all of the specimens in the temperature range of 420 to 650°C, and a swelling peak was observed to form at 550°C. The void suppression effect of nickel additions did not occur in these alloys. Precipitates were formed in the matrix and/or on grain boundaries and were mostly identified as M23C6. The composition in the grain boundary area changed, and the chromium (Cr) concentration near the precipitates became higher. On the other hand, manganese and chromium were depleted, and nickel was enriched in the grain boundary area, but without precipitation. Other phases such as ferrite and sigma could not be recognized. Thus, it was revealed that the addition of nickel to Fe-Cr-Mn alloy stabilizes the austenite even in the grain boundary area where segregation is marked.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
An experiment conducted at ~400 degrees C on simple model austenitic alloys (Fe-15Cr-16Ni and Fe-15Cr-16Ni-0.25Ti, both with and without 500 appm boron) irradiated in the FFTF fast reactor at seven different dpa rates clearly shows that lowering of the atomic displacement rate leads to a pronounced reduction in the transient regime of void swelling. While the steady state swelling rate (~1%/dpa) of these alloys is unaffected by changes in the dpa rate, the transient regime of swelling can vary from
Author: WL. Bell Publisher: ISBN: Category : Ion bombardment Languages : en Pages : 13
Book Description
The effect of reactor irradiation on the microstructural stabilities of several high-nickel-content superalloys was evaluated by transmission electron microscopy. The alloys include Nimonic PE16 and the Inconel alloys 706 and 718. Specimens were irradiated in sealed, unstressed, sodium-filled capsules in the Experimental Breeder Reactor II. Irradiation temperatures ranged from 399 to 649°C (750-1200°F); specimens accumulated a peak fluence of 6 x 1022 n/cm2, E > 0.1 MeV. While little or no microstructural changes were observed in Nimonic PE16, the Inconels exhibited overaging precipitation effects -- in particular, the formation of the stable overaging precipitate, eta -- which increased with temperature in the range studied. Inconel 706 exhibited the more pronounced overaging effects, i.e., larger and coarser eta plates, consistent with its higher titanium-to-aluminum ratio. In general, the precipitation features noted in all three alloys were similar to those observed in identical material after ion bombardment with high energy nickel ions at comparable temperatures. (The latter work was presented in a similar symposium and published in ASTM STP 611). The ion bombardment work has thus correctly predicted the microstructural response of these alloys to fast neutron irradiation.
Author: Publisher: ISBN: Category : Languages : en Pages : 8
Book Description
The objectives of this effort is to identify the mechanisms involved in the radiation-induced evolution of microstructure in materials intended for fusion applications. The results of this study are useful in interpreting the results of several other ongoing experiments involving either spectral or isotopic tailoring to study the effects of helium on microstructure evolution. Ion-irradiated Fe-15Cr-XNi (X = 20, 35, 45, 60, 75) ternary alloys and a 15Cr-85Ni binary alloy were examined after bombardment at 675°C and compared to earlier observations made on these same alloys after irradiation in EBR-II at 510 or 538°C. The response of the ion-irradiated microstructures to nickel content appears to be very consistent with that of neutron irradiation even though there are four orders of magnitude difference in displacement rate and over 200°C difference in temperature. It appears that the transition to higher rates of swelling during both types of irradiation is related to the operation of some mechanisms that is not directly associated with void nucleation. 6 refs., 8 figs.
Author: T. Muroga Publisher: ISBN: Category : Austenitic alloys Languages : en Pages : 12
Book Description
Fe-16Cr-17Ni ternary alloy and those with addition of 0.024P, 0.1P and 0.1P+0.25Ti were irradiated with fast neutrons in FFTF/MOTA at 793 K and 874 K to 33 dpa and 60 dpa. For the purpose of investigating helium production effect, two levels of 10B were doped for each alloy. The microstructures and their relation with tensile properties were examined. The yield stress change was correlated with the density of phosphide precipitates.
Author: H. Watanabe Publisher: ISBN: Category : Ion irradiation Languages : en Pages : 15
Book Description
A series of Fe-Cr-35Ni alloys was irradiated to doses ranging from 12 to 36 dpa with fast neutrons at 375-600°C and to 59-117 dpa at 675°C with Ni+ ions. The primary purpose of this study was to examine the effect of silicon and titanium on both microstructural evolution and the tendency of Fe-Cr-35Ni alloys to spinodally decompose during irradiation. As expected, the addition of these solutes suppresses void swelling and alters the microstructural evolution. They do not appear, however, to suppress the tendency toward spinodal-like decomposition, but only to change somewhat the microstructural consequences of the decomposition.
Author: FA. Garner
Author: FA. Garner
Author: H. Kawanishi
Author: 
Author: Jian Gan
Author: H. Takahashi
Author: 
Author: WL. Bell
Author: 
Author: T. Muroga
Author: H. Watanabe