Download or read book Modeling the Effect of Irradiation and Post irradiation Annealing on Grain Boundary Composition in Austenitic Fe Cr Ni Alloys written by and published by . This book was released on 1998 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many irradiation effects in Fe-Cr-Ni alloys such as radiation-induced segregation, radiation-enhanced diffusion, and void swelling are known to vary with bulk alloy composition. The development of microstructural and microchemical changes during irradiation and during post-irradiation annealing is determined by the rate of diffusion of point defects and alloying elements. To accurately predict the changes in grain boundary chemistry due to radiation-induced segregation and post-irradiation annealing, the composition dependence of diffusion parameters, such as the migration energy, must be known. A model has been developed which calculates migration diffusivity. The advantages of this calculational method are that a single set of input parameters can be used for a wide range of bulk alloy compositions, and the effects of local order can easily be incorporated into the calculations. A description of the model is presented, and model calculations are compared to segregation measurements from seven different iron-chromium-nickel alloys, irradiated with protons to doses from 0.1 to 3.0 dpa at temperatures between 200 C and 600 C. Results show that segregation trends can be modeled using a single set of input parameters with the difference between model calculation and measurement being less than 5 at%, but usually less than 2 at%. Additionally, model predictions are compared to grain boundary composition measurements of neutron irradiated 304 stainless steel following annealing. For the limited annealing data available, model calculations correctly predict the magnitude and time scale for recovery of the grain boundary composition.
Download or read book Modeling of Radiation induced Segregation in Austenitic Fe Cr Ni Alloys written by Todd Randall Allen and published by . This book was released on 1997 with total page 926 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 1983 with total page 1226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Grain Boundary Sensitive Design in Fe and Ni Based Alloys for Materials Response in Irradiation Environments written by Christopher Michael Barr and published by . This book was released on 2016 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ni and Fe based fcc alloys are frequently used as critical structural materials in nuclear energy applications. However, despite extensive studies, fundamental questions remain regarding point defect migration and solute segregation to grain boundaries after high temperature irradiation and corrosion. Specifically, a systematic study on the role of grain size and grain boundary character must be completed to develop insights into new material or processing routes that have enhanced radiation tolerance, improved corrosion resistance, and thermal stability. In this dissertation, an experimental approach is used to examine the response of grain boundary character and grain size in a both model and engineering alloys under extreme environments. After severe plastic deformation and thermomechanical processing to induce a range of grain boundary types and grain sizes, heavy ion irradiation was carried out at a range of temperatures. Post-irradiation analysis of specific grain boundaries using TEM/STEM and atom probe tomography is used to examine the interaction of irradiation induced defects, defect denuded zones, and deleterious Cr solute segregation as function of grain boundary character and grain size. The results indicate variations observed in the Cr depletion and defect evolution as a function of the grain boundary plane and coherency. The ultrafine grain size indicated a grain size dependent response with reduced defect size. Overall, the work highlights the critical role for considering both the grain boundary character distribution and ultrafine grain sizes for the development of new advanced alloys for extreme environments.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975-08 with total page 958 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Nuclear Materials written by and published by Elsevier. This book was released on 2020-07-22 with total page 4871 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials in a nuclear environment are exposed to extreme conditions of radiation, temperature and/or corrosion, and in many cases the combination of these makes the material behavior very different from conventional materials. This is evident for the four major technological challenges the nuclear technology domain is facing currently: (i) long-term operation of existing Generation II nuclear power plants, (ii) the design of the next generation reactors (Generation IV), (iii) the construction of the ITER fusion reactor in Cadarache (France), (iv) and the intermediate and final disposal of nuclear waste. In order to address these challenges, engineers and designers need to know the properties of a wide variety of materials under these conditions and to understand the underlying processes affecting changes in their behavior, in order to assess their performance and to determine the limits of operation. Comprehensive Nuclear Materials, Second Edition, Seven Volume Set provides broad ranging, validated summaries of all the major topics in the field of nuclear material research for fission as well as fusion reactor systems. Attention is given to the fundamental scientific aspects of nuclear materials: fuel and structural materials for fission reactors, waste materials, and materials for fusion reactors. The articles are written at a level that allows undergraduate students to understand the material, while providing active researchers with a ready reference resource of information. Most of the chapters from the first Edition have been revised and updated and a significant number of new topics are covered in completely new material. During the ten years between the two editions, the challenge for applications of nuclear materials has been significantly impacted by world events, public awareness, and technological innovation. Materials play a key role as enablers of new technologies, and we trust that this new edition of Comprehensive Nuclear Materials has captured the key recent developments. Critically reviews the major classes and functions of materials, supporting the selection, assessment, validation and engineering of materials in extreme nuclear environments Comprehensive resource for up-to-date and authoritative information which is not always available elsewhere, even in journals Provides an in-depth treatment of materials modeling and simulation, with a specific focus on nuclear issues Serves as an excellent entry point for students and researchers new to the field
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 324 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 1995-07 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Irradiation Effects on Fe Cr Alloys written by Rong Hu and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferritic chromium steels are important structural materials for future nuclear fission and fusion reactors due to their advantages over traditional austenitic steels, including low swelling rates, better thermal fatigue resistance, and lower thermal expansion coefficients. Radiation-induced segregation or depletion (RIS/RID) of solute atoms at grain boundaries is considered to be a potentially significant phenomenon for structural materials because of its potentially detrimental role in affecting microstructure and furthermore mechanical properties. However, the behaviour of Cr at grain boundaries in ferritic steels is not well understood. Both segregation and depletion of Cr at grain boundary under irradiation have been previously observed and no clear dependency on irradiation condition or alloy type has been presented. Furthermore, ferritic alloys are known to undergo hardening and embrittlement after thermal aging in the temperature range of 300-550DC and this phenomenon is related with a and a' phase separation occurring in the solid solution. However the low temperature a-a' miscibility gap in the currently used phase diagram is extrapolated from high temperature results and conflicts with many experimental observations. To understand the Cr behaviour at gram boundaries in ferritic steels under irradiation, a systematic approach combining SEM/EBSD, FIB specimen preparation and APT analysis has been developed and successfully applied to a Fe- 15.2at%Cr to investigate the effect of pre-irradiation chemistry, grain boundary misorientation, impurities, irradiation damage, irradiation depth, and other possible factors to get a better understanding of RIS/RID phenomena. Both low sigma boundaries and randomly selected high angle boundaries have been investigated in detail. Systematic differences between the behaviour of different classes of boundaries had been observed, and the operating mechanisms are also discussed in this thesis. The maximum separation method has been applied on APT data to study the C- enriched clusters and Cr-enriched clusters, which were not directly visible on the atom maps. The composition of the Cr-enriched clusters was consistent with a' phase and the irradiation was found to accelerate the nucleation rather than the growth of these clusters. Such results provided important information in re- determining the a-a' phase boundary.
Download or read book Materials Transactions JIM written by and published by . This book was released on 1994 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precipitation Sensitivity to Alloy Composition in Fe Cr Mn Austenitic Steels Developed for Reduced Activation for Fusion Application written by RL. Klueh and published by . This book was released on 1990 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Special austenitic steels are being designed in which alloying elements like molybdenum, niobium, and nickel are replaced with manganese, tungsten, vanadium, titanium, and/or tantalum to reduce the long-term radioactivity induced by fusion reactor irradiation. However, the new steels still need to have properties otherwise similar to commercial steels like Type 316. Precipitation strongly affects strength and radiation-resistance in austenitic steels during irradiation at 400 to 600°C, and precipitation is also usually quite sensitive to alloy composition. The initial stage of development was to define a base Fe-Cr-Mn-C composition that formed stable austenite after annealing and cold-working, and resisted recovery or excessive formation of coarse carbide and intermetallic phases during elevated temperature annealing. These studies produced a Fe-12Cr-20Mn-0.25C base alloy. The next stage was to add the minor alloying elements titanium, vanadium, phosphorous, and boron for more strength and radiation-resistance. One of the goals was to produce fine MC precipitation behavior similar to the Ti-modified Fe-Cr-Ni prime candidate alloy (PCA). Additions of Ti + V + P + B produced fine MC precipitation along network dislocations and recovery/re-crystallization resistance in 20% cold-worked material aged at 800° for 168 h, whereas tungsten, titanium, W + Ti, or Ti + P + B additions did not. Addition of W +Ti + V + P + B also produced fine MC, but caused some ? phase formation and more recrystallization as well. These new alloys, therefore, achieved several of the initial design goals. Their fine MC precipitation and recovery/recrystallization behavior during aging is similar to that of the PCA. Calculations show that the new steels have over 103 times less long-term radioactivity than Type 316.
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 Government Reports Announcements Index written by and published by . This book was released on 1992 with total page 1244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts Index written by and published by . This book was released on 1996 with total page 1622 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 1994 with total page 998 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compositional Redistribution in Fe Ni Cr Alloys Under Proton Irradiation written by T. Kimoto and published by . This book was released on 1987 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The compositional redistribution in the direction of depth in austenitic Fe-Ni-Cr-Si-C alloys under 200-keV proton irradiation was examined experimentally using the cross-section technique. After the solution-annealed Fe-25.5Ni-14.7Cr-0.97Si-0.026C and Fe-25.7Ni-14.5Cr-2.85Si-0.026C alloys were irradiated at 873 K by 200-keV protons to the dose of 175 dpa at the peak-damage position for the different irradiation times of 0.1 and 1.37 Ms, the depth profile of composition was measured with an energy dispersive X-ray microanalyzer. Significant depletion of nickel and enrichment of chromium were observed in the peak-damage region ranging from about 0.85 to 1.05 ?m in depth, similarly in both the short-time (0.1 Ms) and long-time (1.37 Ms) irradiations. Slight enrichment of iron and slight depletion of silicon were also observed in the peak-damage region. The observed compositional changes in the peak-damage region is in good qualitative agreement with theoretical prediction, although some quantitative discrepancies between them remain.
Download or read book Composition Depth Profiles and the Effects of Annealing for Ion implated Alloys written by Arthur B. Campbell and published by . This book was released on 1979 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
