Download or read book Radiation induced Solute Segregation in Ferritic Stainless Steels written by Gary John Mahon and published by . This book was released on 1986 with total page 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 Modeling the Effects of Oversize Solute Additions on Radiation Induced Segregation in Austenitic Stainless Steels written by GS. Was and published by . This book was released on 2005 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oversize solute additions to stainless steels hold promise for reducing radiation-induced segregation (RIS), possibly delaying the onset and severity of irradiation-assisted stress-corrosion cracking (IASCC). The Modified Inverse Kirkendall (MIK) model for RIS in austenitic stainless steels was adapted to include the effects of defect trapping, which is expected to be caused by oversized solutes, on RIS. The model accounts for the sensitivity of RIS to both dose rate and temperature. Model results show that the primary contribution to the reduction in RIS occurs through vacancy trapping and recombination with migrating interstitials, requiring strong solute binding energies on the order of 1.0 eV. The maximum reduction in RIS due to defect trapping increases with dose rate and temperature. The general trends of the model are consistent with experimental data from proton and neutron irradiations.

Download or read book Radiation Induced Solute Segregation and Stress Corrosion Cracking Study of AISI 304 and AISI 304L Stainless Steels written by WJ. Liu and published by . This book was released on 1994 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation induced solute segregation (RIS) of chromium, nickel, and minor elements (e.g., Si, P, S, etc.) in the vicinity of grain boundaries and its influences on intergranular stress corrosion cracking (IGSCC) of commercial purity AISI 304 and AISI 304L austenitic stainless steels were investigated in this study. High energy protons were used for producing irradiation environment.

Download or read book Solute Segregation and Void Formation on Grain Boundaries in Electron Irradiated Type 316 Stainless Steel written by S. Ohnuki and published by . This book was released on 1985 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation-induced segregation and void formation on grain boundaries in titanium-modified Type 316 stainless steel were investigated by electron irradiation and X-ray microanalysis (EDX). Strong enrichment and depletion of solutes were observed on grain boundaries during irradiation. Moreover, preferential void formation on grain boundaries occurred and grain boundary migration was induced by the irradiation. These facts indicate that grain boundaries act as preferential sinks for radiation-induced point defects, and the sink behavior may be changed by the development of the segregation under irradiation.

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 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radiation induced Segregation in Austenitic Stainless Steels written by and published by . This book was released on 1991 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement and Modeling of Radiation induced Grain Boundary Segregation in Stainless Steels written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Determination of Radiation Induced Segregation Susceptibility in Austenitic Stainless Steels written by Hilaire Mansoux and published by . This book was released on 1994 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Modelling of Combined Radiation Induced and Thermal Non Equilibrium Segregation of Chromium in Neutron Irradiated Austenitic Stainless Steels written by CC. Goodwin and published by . This book was released on 1999 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model of the radiation-induced segregation (RIS) and thermal non- equilibrium segregation (TNES) at grain boundaries has been established within a phenomenological theory. This model indicates that the magnitude and extent of segregation is dependent upon the formation of solute-point defect complexes that migrate to grain boundaries. Theoretical predictions are made for the TNES and RIS of chromium in austenitic stainless steels for the first time. The results indicate that for TNES, chromium creates a positive binding energy in the complex, and is thus enriched at the grain boundary. For RIS, chromium produces a negative binding energy in the complex, and is thus depleted at the grain boundary. The combined effect of the two segregation mechanisms is discussed in relation to the evolution of the segregation profile exhibited by the grain boundary. The segregation profiles are shown to be illustrative of analytically measured profiles for similarly treated materials.

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.

Download or read book The Influence of Pre irradiation Heat Treatments on Thermal Non equilibrium and Radiation induced Segregation Behavior in Model Austenitic Stainless Steel Alloys written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of pre-irradiation heat treatments on thermal non-equilibrium grain boundary segregation (TNES) and subsequent radiation-induced grain boundary segregation (RIS) is studied in a series of model austenitic stainless steels. The alloys used for this study are based on AISI 316 stainless steel and have the following nominal compositions: Fe-16Cr-13Ni-1.25Mn (base 316), Fe-16Cr-13Ni-1.25Mn-2.0Mo (316 + Mo) and Fe-16Cr-13Ni-1.25Mn-2.0Mo-0.07P (316 + Mo + P). Samples were heat treated at temperatures ranging from 1100 to 1300 C and cooled at 4 different rates (salt brine quench, water quench, air cool and furnace cool) to evaluate the effect of annealing temperature and quench rate on TNES. The alloys were than processed with the treatment (temperature and cooling rate) that resulted in the maximum Cr enrichment. Alloys with and without the heat treatment to enrich the grain boundaries with Cr were characterized following irradiation to 1 dpa at 400 C with high-energy protons in order to understand the influence of alloying additions and pre-irradiation grain boundary chemistry on irradiation-induced elemental enrichment and depletion profiles. Various mechanistic models will be examined to explain the observed behavior.

Download or read book AEM and AES of Radiation induced Segregation in Proton irradiated Stainless Steels written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radiation Induced Segregation in High Chromium Ferritic martensitic Steels written by and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: High Cr ferritic/martensitic (F/M) steels including nano-featured oxide dispersion strengthened steels (NF-ODS) are a candidate material class for advanced fission and fusion nuclear reactor designs. F/M steels have excellent high temperature strength, low swelling rates and the recent developments in NF-ODS steels has improved their high temperature creep performance. A concern for F/M steels is their radiation induced segregation (RIS) response while in-service. RIS occurs when atomic fluxes preferentially couple to point defect fluxes to defect sinks such as grain boundaries (GBs). For F/M steels no conclusive trends or dependencies on the RIS response have been drawn. Interfaces, including grain boundaries and precipitate-matrix interfaces can alter the RIS response. The grain boundary structure could change the point defect interaction at the GB. Changes in the point defect kinetics at a grain boundary could therefore alter the RIS response at the boundary. Furthermore, oxide nanoclusters in NF-ODS steel act as sinks for point defects under irradiation. The surface area and number density of these nanoclusters in NF-ODS steels could alter the point defect fluxes to GBs. Analytical microscopy techniques were conducted to determine the role of grain boundary structure and nanocluster dispersion on the RIS response in irradiated F/M steels. Here, a 9 wt. % Cr model alloy which simulates the structure of commercially available steels and 14YWT NF-ODS alloy was irradiated under numerous conditions. Both alloys were investigated using STEM/EDS and GB misorientation analysis. Experimental results indicate a preferential segregation of Cr to specific GB misorientations in the model F/M steel. Findings in the NF-ODS alloy indicates the stability of nanoclusters within the alloy alters the concentration gradient of the point defects near irradiated GBs. Based on these results, new theories on the role of interfaces in irradiated F/M steels was developed including a rate theory model which accounts for the GB misorientation angle within the RIS model. These theories will stimulate the development of new F/M steels which are highly resistant to RIS while in-service.

Download or read book Measurement and Modeling of Radiation induced Grain Boundary Grain Boundary Segregation in Stainless Steels written by and published by . This book was released on 1995 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Grain boundary radiation-induced segregation (RIS) in Fe-Ni-Cr stainless alloys has been measured and modelled 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 0 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. Impurity segregation (Si and P) was also measured, but only Si enrichment appeared to be radiation-induced. Grain boundary Si levels peaked at an intermediate temperature of (approximately)325°C reaching levels of (approximately)8 at. %. Equilibrium segregation of P was measured in the high-P alloys, but interfacial concentration did not increase with irradiation exposure. Examination of reported RIS in neutron-irradiated stainless steels revealed similar effects of irradiation dose on grain boundary compositional changes for both major alloying and impurity element's. The Inverse Kirkendall model accurately predicted major alloying element RIS in ion- and neutron-irradiated alloys over the wide range of temperature and dose conditions. In addition, preliminary calculations indicate that the Johnson-Lam model can reasonably estimate grain boundary Si enrichment if back diffusion is enhanced.

Download or read book Radiation Induced Segregation in 20Cr 25Ni Nb Stainless Steels by HVEM Simulation written by Mark Andrew Ashworth and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Influence of Pre Irradiation Heat Treatments on Thermal Non Equilibrium and Radiation Induced Segregation Behavior in Model Austenitic Stainless Steel Alloys written by GS. Was and published by . This book was released on 2004 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of pre-irradiation heat treatments on thermal non-equilibrium grain boundary segregation (TNES) and subsequent radiation-induced grain boundary segregation (RIS) is studied in a series of model austenitic stainless steels. The alloys used for this study are based on AISI 316 stainless steel and have the following nominal compositions: Fe-16Cr-13Ni-1.25Mn (base 316), Fe-16Cr-13Ni-1.25Mn-2.0Mo (316 + Mo) and Fe-16Cr-13Ni-1.25Mn-2.0Mo-0.07P (316 + Mo + P). Samples were heat treated at temperatures ranging from 1100 to 1300°C and cooled at four different rates (salt brine quench, water quench, air cool and furnace cool) to evaluate the effect of annealing temperature and quench rate on TNES. The alloys were then processed with the treatment (temperature and cooling rate) that resulted in the maximum Cr enrichment. Alloys with and without the heat treatment to enrich the grain boundaries with Cr were characterized following irradiation to 1 dpa at 400°C with high-energy protons in order to understand the influence of alloying additions and pre-irradiation grain boundary chemistry on irradiation-induced elemental enrichment and depletion profiles. Various mechanistic models will be examined to explain the observed behavior.