Download or read book Radiation induced segregation in Fe Cr Ni alloys written by A. D. Marwick and published by . This book was released on 1983 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Analyses of Radiation induced Segregation in Fe Cr Ni Alloys written by V. A. Pečenkin and published by . This book was released on 1995 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Radiation Induced Segregation of Phosphorus in Nickel and Fe Cr Ni Alloys written by CA. English and published by . This book was released on 1990 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation-induced segregation of phosphorus has been studied in nickel and Fe-15Cr-Ni alloys, with nickel content varying from 15 to 70 atomic%, using accelerator based techniques and secondary ion mass spectrometry. Experiments in pure nickel demonstrated that phosphorus segregates by an interstitial mechanism. The similarity of segregation in nickel and Fe-15Cr-Ni alloys suggests that this conclusion also applies to the alloys. We have confirmed that manganese segregates by solute-vacancy exchanges. Phosphorus, manganese, and silicon segregation in the alloys was found to be strongly dependent on nickel content. The composition dependence was, however, similar for all the solutes, independent of mechanism. Segregation was a minimum for nickel contents about 45 atomic%. Possible explanations for this are discussed.

Download or read book Evaluation of Radiation Induced Segregation in Fe Ni Cr Alloys written by Carlos Daniel Flores and published by . This book was released on 1994 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Radiation Induced Segregation on Precipitate Stability and Swelling in Irradiated Alloys written by VA. Pechenkin and published by . This book was released on 1999 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The radiation-induced segregation of alloy components near point defect sinks with a particular attention to Fe-Cr-Ni based alloys is analyzed. The influence of point defect generation rate on temperature ranges of stability for radiation-retarded M23C6 and radiation-induced Ni3Si precipitates in austenitic stainless steels is considered. A method of calculation of steady-state segregation-induced bias in irradiated binary alloys, taking into account Kirkendall forces and drift forces caused by point defect migration and formation energy gradients near sinks, is proposed. Contributions of various forces to the bias in Fe-Cr-Ni and V-Fe alloys are evaluated. The effect of void-precipitate association on swelling is analyzed. The radiation-induced segregation of components and segregation-induced bias for motionless and moving grain boundaries in a Fe-Cr-Ni alloy are calculated by solving the set of coupled diffusion equations for component and point defect concentrations.

Download or read book On Radiation induced Segregation and the Compositional Dependence of Swelling in Fe Ni Cr Alloys written by W. G. Wolfer and published by . This book was released on 1982 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On Radiation induced Segregation and the Compositional Dependence of Swelling in Fe Ni Cr Alloys written by W. G. Wolfer and published by . This book was released on 1982 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modelling of Radiation Induced Segregation in Austenitic Fe Alloys at the Atomistic Level written by Jean-Baptiste Piochaud and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In pressurized water reactors, under irradiation internal structures are subject of irradiation assisted stress corrosion cracking which is influenced by radiation induced segregation (RIS). In this work RIS of 316 stainless steels is modelled considering a model ternary Fe-10Ni-20Cr alloy. For this purpose we have built an Fe-Ni-Cr pair interaction model to simulate RIS at the atomistic level using an atomistic kinetic Monte Carlo approach. The pair interactions have been deduced from density functional theory (DFT) data available in the pure fcc systems but also from DFT calculations we have performed in the Fe-10Ni-20Cr target alloy. Point defect formation energies were calculated and found to depend strongly on the local environment of the defect. As a consequence, a rather good estimation of these energies can be obtained from the knowledge of the number and respective positions of the Ni and Cr atoms in the vicinity of the defect. This work shows that a model based only on interaction parameters between elements positioned in perfect lattice sites (solute atoms and vacancy) cannot capture alone both the thermodynamic and the kinetic aspect of RIS. A more accurate of estimating the barriers encountered by the diffusing species is required than the one used in our model, which has to depend on the saddle point environment. This study therefore shows thus the need to estimate point defect migration energies using the DFT approach to calibrate a model that can be used in the framework of atomic kinetic Monte Carlo simulations. We also found that the reproduction by our pair interaction model of DFT data for the self-interstitial atoms was found to be incompatible with the modelling of RIS under electron irradiation.

Download or read book Modeling Radiation Induced Segregation in Iron Chromium Alloys written by and published by . This book was released on 2015 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation induced segregation in ferritic Fe-Cr alloys is studied by Atomistic Kinetic Monte Carlo simulations that include di usion of chemical species by vacancy and interstitial migration, recombination, and elimination at sinks. The parameters of the di usion model are tted to DFT calculations. Transport coe cients that control the coupling between di usion of defects and chemical species are measured in dilute and concentrated alloys. Radiation induced segregation near grain boundaries is directly simulated with this model. We nd that the di usion of vacancies toward sinks leads to a Cr depletion. Meanwhile, the di usion of self-interstitials causes an enrichment of Cr in the vicinity of sinks. For concentrations lower than 15%Cr, we predict that sinks will be enriched with Cr for temperatures lower than a threshold. When the temperature is above this threshold value, the sinks will be depleted in Cr. These results are compared to previous experimental studies and models. Cases of radiation induced precipitation and radiation accelerated precipitation are considered.

Download or read book Radiation induced Changes in Microstructure written by F. A. Garner and published by ASTM International. This book was released on 1987 with total page 919 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radiation induced Segregation and the Relationship to Physical Properties in Irradiated Austenitic Alloys written by and published by . This book was released on 2002 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation-induced changes in composition are studied because these changes can degrade failure of materials irradiated in nuclear reactors. In this work, the effect of alloy composition on radiation-induced segregation, hardening, and void swelling is presented. Five alloys, Fe-18Cr-8Ni, Fe-16Cr-13Ni, Fe-18Cr-40Ni, Fe-16Cr-13Ni+Mo, and Fe-16Cr-13Ni+Mo+P (all compositions in wt. %), were irradiated with 3.2 MeV protons at 400 C to a dose of 0.5 displacements per atom. The change in grain boundary composition was measured using field emission gun scanning transmission electron microscopy and the hardening was measured using Vickers indentation. Void swelling is calculated from the void size distribution measured using transmission electron microscopy. After irradiation, Cr depletes and Ni enriches at grain boundaries. Increasing bulk Ni concentration causes greater Cr depletion and Ni enrichment at grain boundaries. For alloys with 16 Cr, the addition of P reduces the Cr depletion and Ni enrichment. Hardening does not directly correlate with composition, but a framework for isolating the effect of hardening and segregation on cracking is suggested. The amount of void swelling in the irradiated material is shown to correspond inversely with segregation. Those alloys with greater segregation tend to swell less.

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 Fundamentals of Radiation Materials Science written by GARY S. WAS and published by Springer. This book was released on 2016-07-08 with total page 1014 pages. Available in PDF, EPUB and Kindle. Book excerpt: The revised second edition of this established text offers readers a significantly expanded introduction to the effects of radiation on metals and alloys. It describes the various processes that occur when energetic particles strike a solid, inducing changes to the physical and mechanical properties of the material. Specifically it covers particle interaction with the metals and alloys used in nuclear reactor cores and hence subject to intense radiation fields. It describes the basics of particle-atom interaction for a range of particle types, the amount and spatial extent of the resulting radiation damage, the physical effects of irradiation and the changes in mechanical behavior of irradiated metals and alloys. Updated throughout, some major enhancements for the new edition include improved treatment of low- and intermediate-energy elastic collisions and stopping power, expanded sections on molecular dynamics and kinetic Monte Carlo methodologies describing collision cascade evolution, new treatment of the multi-frequency model of diffusion, numerous examples of RIS in austenitic and ferritic-martensitic alloys, expanded treatment of in-cascade defect clustering, cluster evolution, and cluster mobility, new discussion of void behavior near grain boundaries, a new section on ion beam assisted deposition, and reorganization of hardening, creep and fracture of irradiated materials (Chaps 12-14) to provide a smoother and more integrated transition between the topics. The book also contains two new chapters. Chapter 15 focuses on the fundamentals of corrosion and stress corrosion cracking, covering forms of corrosion, corrosion thermodynamics, corrosion kinetics, polarization theory, passivity, crevice corrosion, and stress corrosion cracking. Chapter 16 extends this treatment and considers the effects of irradiation on corrosion and environmentally assisted corrosion, including the effects of irradiation on water chemistry and the mechanisms of irradiation-induced stress corrosion cracking. The book maintains the previous style, concepts are developed systematically and quantitatively, supported by worked examples, references for further reading and end-of-chapter problem sets. Aimed primarily at students of materials sciences and nuclear engineering, the book will also provide a valuable resource for academic and industrial research professionals. Reviews of the first edition: "...nomenclature, problems and separate bibliography at the end of each chapter allow to the reader to reach a straightforward understanding of the subject, part by part. ... this book is very pleasant to read, well documented and can be seen as a very good introduction to the effects of irradiation on matter, or as a good references compilation for experimented readers." - Pauly Nicolas, Physicalia Magazine, Vol. 30 (1), 2008 “The text provides enough fundamental material to explain the science and theory behind radiation effects in solids, but is also written at a high enough level to be useful for professional scientists. Its organization suits a graduate level materials or nuclear science course... the text was written by a noted expert and active researcher in the field of radiation effects in metals, the selection and organization of the material is excellent... may well become a necessary reference for graduate students and researchers in radiation materials science.” - L.M. Dougherty, 07/11/2008, JOM, the Member Journal of The Minerals, Metals and Materials Society.

Download or read book Characterisation of Radiation Damage by Transmission Electron Microscopy written by M.L Jenkins and published by CRC Press. This book was released on 2000-11-21 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Characterization of Radiation Damage by Transmission Electron Microscopy details the electron microscopy methods used to investigate complex and fine-scale microstructures, such as those produced by fast-particle irradiation of metals or ion implantation of semiconductors. The book focuses on the methods used to characterize small point-defect clusters, such as dislocation loops, because the coverage in general microscopy textbooks is limited and omits many of the problems associated with the analysis of these defects. The book also describes in situ, high-resolution, and analytical techniques. Techniques are illustrated with examples, providing a solid overview of the contribution of TEM to radiation damage mechanisms. The book is most useful to researchers in, or entering into, the field of defect analysis in materials.

Download or read book Radiation induced Grain Boundary Segregation in Austenitic Stainless Steels written by and published by . This book was released on 1994 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation-induced segregation (RIS) to grain boundaries in Fe-Ni-Cr-Si stainless alloys has been measured as a function of irradiation temperature and dose. Heavy-ion irradiation was used to produce damage levels from 1 to 20 displacements per atom (dpa) at temperatures from 175 to 550°C. Measured Fe, Ni, and Cr segregation increased sharply with irradiation dose (from G to 5 dpa) and temperature (from 175 to about 350°C). However, grain boundary concentrations did not change significantly as dose or temperatures were further increased. Although interfacial compositions were similar, the width of radiation-induced enrichment or depletion profiles increased consistently with increasing dose or temperature. Impurity segregation (Si and P) was also measured, but only Si enrichment appeared to be radiation-induced. Grain boundary Si peaked at levels approaching 10 at% after irradiation doses to 10 dpa at an intermediate temperature of 325°C. No evidence of grain boundary silicide precipitation was detected after irradiation at any temperature. Equilibrium segregation of P was measured in the high-P alloys, but interfacial concentration did not increase with irradiation exposure. Comparisons to reported RIS in neutron-irradiated stainless steels revealed similar grain boundary compositional changes for both major alloying and impurity elements.

Download or read book Effects of Radiation on Materials written by N. H. Packan and published by ASTM International. This book was released on 1990 with total page 679 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Effects of Radiation on Materials: Fourteenth International Symposium was presented at Andover, MA, June 1988. The symposium was sponsored by ASTM Committee E-10 on Nuclear Technology and Applications. The papers from the first three days of the symposium appear in the two volumes of this publication. Volume I encompasses radiation damage- induced microstructures; point defect, solute, and gas atom effects; atomic-level measurement techniques; and applications of theory. Volume II includes mechanical behavior, all papers dealing with pressure-vessel steels, breeder reactor components, dosimetry, and nuclear fuels. The fourth day of the symposium was devoted to the single topic of reduced-activation materials (see TK9204). The two volumes are separately sold at $127 and $128 respectively; each is independently indexed. Annotation copyrighted by Book News, Inc., Portland, OR.