Download or read book Microstructure Modeling of a 316L Stainless Steel Irradiated with Electrons written by J. Henry and published by . This book was released on 2000 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented here is a first step in an effort to develop a rate theory model useful for the prediction of microstructural evolution of austenitic stainless steels in typical irradiation conditions for PWR core internals. An important difficulty associated with this type of model is the lack of well known material parameters (apparent defect migration energies, bias factors, etc.), which depend on the composition of the alloy and on the presence of impurities. The approach adopted here consists in finding an adequate set of parameters which results in a good agreement between model predictions and microstructural data after irradiating a 316L stainless steel at different temperatures in a 1 MeV electron microscope. Model results can then be compared with microstructural data corresponding to different irradiation conditions. We have chosen here to perform irradiations at low damage rate using 3 MeV electrons, which is a simpler case compared for example with neutron irradiations. We have found that calculated and measured densities of interstitial loops are in good agreement if a small fraction of the generated defects is considered to be in the form of di-interstitials, in accordance with molecular dynamics results. In the future, we intend to modify the model for the case of neutron irradiations. The same procedure as implemented here for the choice of material parameters (i.e., 1 MeV electron irradiations) will be carried out for different types of austenitic stainless steels. Model predictions will then be compared with microstructural observations obtained after irradiations of the steels up to different doses in an experimental reactor.
Download or read book Effects of Radiation on Materials written by Margaret L. Hamilton and published by ASTM International. This book was released on 2000 with total page 1266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Composite Model for Segregation and Microstructural Evolution Under Electron Irradiation written by S. Watanabe and published by . This book was released on 2000 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have investigated radiation-induced segregation (RIS) near a grain boundary in an austenitic stainless steel under electron irradiation taking into account the simultaneous evolution of faulted dislocation loops and network dislocations by a composite model. It has been found that dislocation free zones (DLFZ) formed in the vicinity of the grain boundary by the irradiation, and we carried out direct observation of the DLFZ formation by in-situ irradiation in a high-voltage electron microscope (HVEM). Prediction of temperature and dose dependence of DLFZ formation agreed with experimental results. The inter-relationship between RIS and DLFZ formation near a grain boundary has been substantially clarified. RIS and DLFZ were understood considering point defect and solute flow associated with the excess defect to the grain boundary.
Download or read book Radiation Effects on the Mechanical Properties and Microstructure of Type 304 Stainless Steel written by J. S. Armijo and published by . This book was released on 1964 with total page 94 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 Microstructure of Irradiated Materials Volume 373 written by Ian M. Robertson and published by . This book was released on 1995-04-03 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of the symposium, which was held at the 1994 MRS Fall Meeting, was on the changes produced in the microstructure of metals, ceramics, and semiconductors by irradiation with energetic particles. This proceedings volume contains invited and contributed papers. Among the topics are computer simulation of displacement cascade damage in metals; radiation effects in ceramic insulators; and computer simulation of thermal annealing effects of self implanted silicon. Annotation copyright by Book News, Inc., Portland, OR
Download or read book Microstructure Evolution During Irradiation Volume 439 written by Ian M. Robertson and published by . This book was released on 1997-06-25 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book from MRS discusses the evolution of a material's microstructure as a result of its interaction with energetic particles such as ions, neutrons or electrons. The book is inter-disciplinary and emphasizes all classes of materials including metals, intermetallic compounds, ceramics, polymers, superconductors, semiconductors and insulators. A strong focus is placed on experimental techniques for measuring and quantifying damage and microstructure changes, and on computer simulation techniques for predicting and understanding this phenomena. Topics include: ion-implantation damage in semiconductors; radiation damage in metals; radiation damage in ceramics; radiation effects in polymers and beam-induced effects.
Download or read book Swelling in Electron Irradiated Type 316 Stainless Steel written by FA. Garner and published by . This book was released on 1975 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: To study void swelling behavior for clues regarding the anticipated performance of Type 316 stainless steel in fast reactor environments, two series of electron irradiation experiments were conducted. The first series of experiments were conducted on material which was prototypic of fast test reactor (FTR) steels in composition, but not microstructure. The results indicated that swelling values exceeding 100 percent could easily be obtained in annealed Type 316 and that cold rolling of this material could lead to an increase in the incubation fluence and a reduction in the subsequent swelling rate. The void volume fraction in both the annealed and cold-rolled specimens developed at a constant rate after the incubation period.
Download or read book Void Formation in Cold Worked Type 316 Stainless Steel Irradiated with 1 MeV Protons written by DW. Keefer and published by . This book was released on 1975 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cold-worked Type 316 stainless steel was irradiated at 500and 600°C with 1-MeV protons. The dependence of void formation on displacement damage, irradiation temperature, and microstructure was studied by transmission electron microscopy. Cold working delays the onset of swelling and reduces it, via a reduction in void size, at both irradiation temperatures. Inhomogeneity in the cold-worked microstructure leads to inhomogeneity in the disposition of voids. Swelling at 600°C is greater than at 500°C; the voids are less numerous but larger at the higher temperature. No change in the cold-worked microstructure can be detected by transmission electron microscopy after 500°C irradiation to 23 displacements per atom. Irradiation to a comparable damage level at 600°C results in almost complete elimination of the cold-worked microstructure. Comparison of the results is made with data from reactor irradiation experiments.
Download or read book Effects of Radiation on Materials written by and published by . This book was released on 2000 with total page 1296 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 The Microstructural Evolution and Swelling Behavior of Type 316 Stainless Steel Irradiated in HFIR written by S. Hamada and published by . This book was released on 1990 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solution annealed (SA) and 20% cold worked (CW) Type 316 (UNS S 31600) stainless steels were irradiated in the high flux isotope reactor (HFIR) to 55 dpa and to 3445 appm helium at 300 to 500°C. The irradiated specimens were examined by transmission electron microscopy (TEM) to evaluate microstructural evolution. At irradiation temperatures of 400°C and below, there was very little difference in the microstructural and swelling behavior between SA and CW material. A high concentration of fine bubbles was uniformly dispersed in the matrix. Swelling was very low (
Download or read book An Investigation of Microstructures and Yield Strengths in Irradiated Austenitic Stainless Steels Using Small Specimen Techniques written by MB. Toloczko and published by . This book was released on 1996 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transmission electron microscopy (TEM) specimens of a first core heat of 316 stainless steel, in both the solution annealed and 20% cold worked condition, were irradiated to 46 dpa at 420°C, to 49 dpa at 520°C, and to 34 dpa at 600°C in FFTF/MOTA. Prior to irradiation, some of the specimens were pre-implanted with approximately 100 appm of helium over one-third of the specimen thickness. Microstructures and mechanical properties of these specimens were examined. Microstructural data was taken from unimplanted zones and were consistent with data in the literature for unimplanted 316 SS. Where possible, irradiation hardening of the alloys was experimentally evaluated by microhardness and shear punch. For comparison, irradiation hardening was also calculated using a barrier hardening model and the microstructural data. Experimentally measured values of yield stress were in agreement with the range of values reported in the literature regardless of helium pre-implantation and were similar to the calculated values.
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 Welding the Inconel 718 Superalloy written by S.G.K. Manikandan and published by Elsevier. This book was released on 2019-05-29 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Welding the Inconel 718 Superalloy: Reduction of Micro-segregation and Laves Phases explores the day-to-day welding business in Alloy 718 and presents solutions to avoid or minimize micro-segregation. It considers the limitations of changing from lab scale models to actual production models and presents new technologies with proven experimental background. Various case studies are presented within the text, as well as proposed solutions backed by experimental evidence. Items previewed in this edition include enhanced cooling rates in the GTA welding process with cryogenic cooling and enhanced dendrite refinement using modified pulse waveform. This work will be useful to researchers from the aerospace, space, power generation, nuclear, and chemical industries, as well as students interested in superalloys and welding. - Resolves the industrial limitations in reducing the formation of laves phases in the welding of alloy 718 - Presents case studies in industrial applications - Discusses new technologies with proven experimental background - Includes a comparison of laves size and distribution between GTAW, EBW, LBW and FW
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975 with total page 700 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 1994-06 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
