Download or read book The Modeling of Radiation Induced Phosphorus Segregation at Point Defect Sinks in Dilute Fe P Alloys written by IA. Stepanov and published by . This book was released on 2004 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Both the intergranular and intragranular segregation of phosphorus may significantly contribute to irradiation embrittlement of reactor pressure vessel steels. The modeling of phosphorus radiation-induced segregation at cylindrical (dislocations), spherical (precipitates and voids) and flat (sample surfaces, grain boundaries) point defect sinks has been carried out in order to compare the kinetics and extent of segregation at various point defect sinks. Dilute Fe-P alloys relevant to model and VVER-440 pressure vessel steels were considered.

Download or read book Effects of Radiation on Materials written by Martin L. Grossbeck and published by ASTM International. This book was released on 2004 with total page 767 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Radiation on Materials written by Stan T. Rosinski and published by ASTM International. This book was released on 2001 with total page 879 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Physical Methods for Materials Characterisation written by Peter E. J. Flewitt and published by CRC Press. This book was released on 2017-12-06 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt: This completely revised and expanded new edition covers the full range of techniques now available for the investigation of materials structure and accurate quantitative determination of microstructural features within materials. It continues to provide the best introductory resource for understanding the interrelationship between microstructure and physical, mechanical, and chemical properties, as well as selection and application of techniques for both basic and applied studies. In particular, changes have been made to reflect developments in analysis of nanoscale and biological materials.

Download or read book Modeling of Phosphorus Accumulation on Grain Boundaries in Iron Alloys Under Irradiation written by IA. Stepanov and published by . This book was released on 2001 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Kinetics of phosphorus accumulation on grain boundaries (GB) in iron-based alloys is treated theoretically, taking into account both the radiation-induced segregation (RIS) in the matrix and the Gibbsian adsorption (GA) at GB. For steady-state conditions analytical expressions are derived for component profiles near GB and component concentrations on GB. Modeling of phosphorus accumulation at GB in iron alloys is carried out using two different models: 1) the McLean's model generalized to take into account the radiation-enhanced phosphorus diffusion via vacancy and interstitial mechanisms as well as RIS near GB, 2) a model of RIS in a ternary Fe-P-Ni alloy accounting for the binding energy of phosphorus atoms with interstitials as well as a possibility of high phosphorus content near GB at high irradiation doses. Predictions of modeling are analyzed regarding the dependence on temperature, dose and Fe and P diffusion parameters available for iron alloys. It is shown that the GB phosphorus concentration calculated as a function of temperature reveals one or two maxima depending on dose and the choice of material parameters.

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 Predictions of Interfacial Phosphorus Segregation in Irradiated Ferritic Steels written by RG. Faulkner and published by . This book was released on 1994 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: A recently developed model for irradiation-induced solute segregation (IRS) is overviewed and applied to the case of phosphorus segregation to grain boundaries in a ferritic matrix. The effects on IRS of irradiation temperature, dose rate and dislocation networks acting as additional point defect sinks are examined. Phosphorus is predicted to segregate at relatively low irradiation temperatures in the range ~ 110°-300°C, depending on dose rate, with peak segregation occurring at ~ 120°C and ~ 150°C at thermal and fast reactor core dose rates, respectively. The principal effect of increasing the matrix dislocation density is to reduce the magnitude of the solute segregation without change in peak temperature.

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 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 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 Development of Computational Tools for Predicting Thermal and Radiation Induced Solute Segregation at Grain Boundaries in Fe based Alloys written by and published by . This book was released on 2016 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation induced segregation (RIS) has been frequently reported in structural materials such as austenitic, ferritic, and ferritic-martensitic stainless steels (SS) that have been widely used in light water reactors (LWRs). RIS has been linked to secondary degradation effects in SS including irradiation induced stress corrosion cracking (IASCC). Earlier studies on thermal segregation in Fe based alloys found that metalloids elements such as P, S, Si, Ge, Sn etc. embrittle the materials when enrichment was observed at grain boundaries (GBs). RIS of Fe-Cr- Ni based austenitic steels has been modeled in the U.S. 2015 fiscal year (FY2015), which identified the pre-enrichment due to thermal segregation can have an important role on the subsequent RIS. The goal of this work is to develop thermal segregation models for alloying elements in steels for future integration with RIS modeling.

Download or read book Metals Abstracts written by and published by . This book was released on 1992 with total page 1796 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermodynamic and Kinetic Modeling on Thermal Segregation of Phosphorus in Iron written by and published by . This book was released on 2016 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation induced segregation (RIS) has been frequently reported in structural materials such as austenitic, ferritic, and ferritic-martensitic stainless steels (SS) that have been widely used in light water reactors (LWRs). RIS has been linked to secondary degradation effects in SS including irradiation induced stress corrosion cracking (IASCC). Earlier studies on thermal segregation in Fe based alloys found that metalloids elements such as P, S, Si, Ge, Sn etc. embrittle the materials when enrichment was observed at grain boundaries. RIS of Fe-Cr-Ni based austenitic steels has been modeled in the U.S. 2015 fiscal year (FY2015), which identified the pre-enrichment due to thermal segregation can have an important role on the subsequent RIS. The goal of this work is to develop thermal segregation models for alloying elements in steels for future integration with RIS modeling.

Download or read book Physics Briefs written by and published by . This book was released on 1993 with total page 1288 pages. Available in PDF, EPUB and Kindle. Book excerpt: