Download or read book The Effects of Nickel on Microstructural Development and Microchemical Changes in Neutron Irradiated Fe Cr Mn Based Steels written by H. Takahashi and published by . This book was released on 1992 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Effects of Radiation on Materials written by Roger E. Stoller and published by ASTM International. This book was released on 1992 with total page 1315 pages. Available in PDF, EPUB and Kindle. Book excerpt: Symposium held in Nashville, Tennessee, June 1990. Almost two-thirds of these 91 papers are authored by researchers outside of the US (including information on research in the former USSR, Japan, and Europe). Topics include: current commercial power reactor systems; microstructural characterization
Download or read book Metals Abstracts written by and published by . This book was released on 1994 with total page 1584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence on Nickel Content on Microstructures of Fe Cr Ni Austenitic Ternaries Irradiated with Fast Neutrons Or Heavy Ions written by FA. Garner and published by . This book was released on 1992 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microstructural and microchemical evolution of Fe-15Cr-XNi and ISCr-85Ni austenitic alloys irradiated with fast neutrons at 510 and 538°C and heavy ions at 675°C was investigated to determine whether common mechanisms of nickel's influence on microstructural development existed under different irradiation conditions. A surprising commonality for these two types of irradiations was observed involving nickel-dependent void densities, dislocation and loop dominance of dislocation structures, and fluence dependence of swelling, void density, and solute segregation. Quantitative analyses of microstructure and microchemistry data snowed that the variation of dislocation sink strength with nickel addition may provide the major mechanisms by which swelling depends on nickel content. Other processes, such as nickel's influence on the mobility of vacancies and the different segregation behavior at sessile and mobile defects, also cooperate to produce the overall behavior.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 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 1990 with total page 946 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microstructural Characterization of Irradiated Fe Cu Ni P Model Steels written by and published by . This book was released on 1987 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microstructure of Fe-Cu-Ni-P model pressure vessel steels after neutron irradiation and thermal aging has been characterized by atom probe field-ion microscopy and augmented by transmission electron microscopy. High densities of small, roughly spherical or disc shaped copper clusters/precipitates were observed in the neutron irradiated alloys that contained copper. Small spherical phosphorus clusters were observed in the irradiated copper-free alloys, and copper phosphides were observed in a high phosphorus Fe-Cu-Ni-P alloy. None of these clusters/precipitates were observed in the thermally aged materials. The increases in the tensile and yield strengths that were observed after neutron irradiation resulted from these clusters and other lattice defects.
Download or read book RADIATION INDUCED MICROSTRUCTURAL DEVELOPMENT AND MICROCHEMICAL CHANGES IN Fe Cr Mn Ni SOLUTE BEARING ALLOYS written by H. TAKAHASHI and published by . This book was released on 1990 with total page 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 1986 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microstructure Evolution in Proton irradiated Austenitic Fe Cr Ni Alloys Under LWR Core Conditions written by Jian Gan and published by . This book was released on 1999 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microstructural Changes in Neutron Irradiated Commercial Alloys written by WL. Bell and published by . This book was released on 1982 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Ductility and Hardening of Neutron Irradiated Fe Cr and Fe Cr Ni Steels written by N. Igata and published by . This book was released on 1992 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fe-Cr and Fe-Ni-Cr steels are candidate alloys for fusion reactor materials. For future design it is important to clarify the general rules of mechanical properties for those alloys irradiated at higher fluence and at higher temperatures. In this investigation, to find general rules for irradiation effects, twelve kinds of commercial Fe-Cr and Fe-Ni-Cr steels were irradiated in JMTR. The total flux was 6 x 1025n/m2, and the irradiation temperature was 743 to 848 K. Yield strength, tensile strength, and uniform ductility at room temperature were observed for all specimens before and after irradiation, and work-hardening exponents were obtained from stress-strain curves of those specimens. In all cases, uniform ductility was equal to the work-hardening exponent, there was a close relationship between strength and uniform ductility, and there was no anomalous behavior in these alloy series. Further study was made of Fe-9Cr-2Mo steel, which was irradiated to 3 x 1026 n/m2 at 673 to 923 K in EBR-II. Electron micrographs for controlled or irradiated specimens were used for the analysis of the change of strength by irradiation. The strength and uniform ductility was interpreted from microstructural aspects.
Download or read book The Influence of Nickel Content on Microstructures of Fe Cr Ni Austenitic Alloys Irradiated with Nickel Ions 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 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.
Download or read book Microstructural and Microchemical Evolution During Fast Neutron Irradiation in Nickel and Nickel Silicon Alloys Doped with Isotopically Controlled Boron written by T. Muroga and published by . This book was released on 1994 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pure nickel and Ni-2wt%Si doped with several levels of boron- 10 (10B) and natural boron(nB) were irradiated in FFTF at 679, 793 and 873 K and 40 dpa, for the purpose of examining the applicability of. boron addition to the study of helium effects. The comparison of B and nB doped specimens showed that boron addition enhances cavity nucleation and growth via its transmutation effect and suppresses the nucleation via its chemical effect. Generally the transmutation effect was dominant at higher temperatures. In Ni-Si alloys, boron's chemical effect in suppressing the cavity density was stronger than that in pure nickel. Ni3Si precipitates were observed at 679 K but not at 793 and 873 K. Radiation-induced segregation of silicon at grain boundaries was most prominent at 793 K. The influence of boron addition on Ni3Si precipitation or the segregation of silicon is not yet clear.
Download or read book Nickel Ion Irradiation Effects on the Microstructure of 2 1 4 Cr 1 Mo Steel and a Comparison with Neutron Irradiation Data written by RA. Dodd and published by . This book was released on 1987 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: A 2 1/4 Cr 1% Mo steel, heat treated to consist of upper and lower bainite and ferrite, has been shown to undergo substantial microstructural modification when irradiated with 14-MeV nickel ions at 500°C to 350 dpa at the peak damage depth. The original cementite (Fe3C) in upper and lower bainite was replaced by Chi phase, M7C3 and M2C in upper bainite, and Chi and M7C3 in lower bainite. The originally precipitate-free ferrite contained a significant fraction of G phase after irradiation. The replacement of Fe3C by M7C3 and M2C is consistent with the fact that M7C3 and M2C form in a quenched and tempered 2 1/4 Cr 1 Mo steel, but at higher tempering temperatures than does Fe3C. On the other hand, Chi and G phases have not been reported to occur in this steel as a result of thermal treatments. The steel is resistant to void swelling, which amounted to 0.2% or less even at the rather high dpa levels employed in this study. The quantitative data for precipitate and void number densities and sizes agree quite well with a companion neutron irradiation study of the same steel possessing an identical microstructure.
Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 1646 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Void Swelling and Microstructural Change in Neutron Irradiated Type 316 Stainless Steel written by M. Itoh and published by . This book was released on 1987 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microstructural observations were made on cold-worked Type 316 stainless steel following fast neutron irradiation to a peak neutron fluence of 1.3 x 1027 n/m2 (E > 0.1 MeV) at temperatures from 400 to 620°C. The results show that nickel depletion in the matrix after neutron irradiation is related to the formation of phosphides and void swelling. Phosphorus in solution retards not only the recovery of dislocations but also the development of nickel- and silicon-rich phases, and this results in suppressing nickel depletion in the matrix and an extension of the transient regime in void swelling. Phosphides are formed during the transient regime at temperatures from 490 to 570°C. After phosphides are formed, retardation effects on both dislocation recovery and the formation of nickel- and silicon-rich phases are lost, and this leads to the onset of void swelling.
