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in creator/contributor: "Bruemmer, S."

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Interfacial precipitation, segregation and deformation in alloy 600: Implications on primary-side IGSCC

A great many unknowns still exist concerning the mechanisms controlling intergranular stress corrosion cracking (IGSCC) of alloy 600 in high-temperature, deaerated water environments. Any proposed mechanism must involve the microstructure, microchemistry and mechanical properties of grain boundary regions. To facilitate basic understanding, specific aspects of alloy 600 metallurgy are reviewed and discussed. Interfacial carbide precipitation, chromium depletion, impurity segregation and local d… more

Date: April 1, 1993

Creator: Bruemmer, S. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Interfacial precipitation, segregation and deformation in alloy 600: Implications on primary-side IGSCC

Date: April 1, 1993

Creator: Bruemmer, S.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation hardening and radiation-induced chromium depletion effects on intergranular stress corrosion cracking of austenitic stainless steels

Available data on neutron-irradiated materials have been analyzed and correlations developed between fluence, yield strength, grain boundary chromium concentration and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in critical fluence (0.2 to 2.5 n/cm[sup 2]) for IGSCC are documented.In many cases, this variability is consistent with yield strength differences among irradiated materials. IGSCC correlated better to yield strength than to fluence fo… more

Date: March 1, 1993

Creator: Bruemmer, S. M. & Simonen, E. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Mechanistic issues for modeling radiation-induced segregation

Model calculations of radiation-induced chromium depletion and radiation-induced nickel enrichment at grain boundaries are compared to measured depletions and enrichments. The model is calibrated to fit chromium depletion in commercial purity 304 stainless steel irradiated in boiling water reactor (BWR) environments. Predicted chromium depletion profiles and the dose dependence of chromium concentration at grain boundaries are in accord with measured trends. Evaluation of chromium and nickel pr… more

Date: March 1, 1993

Creator: Simonen, E. P. & Bruemmer, S. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation hardening and radiation-induced chromium depletion effects on intergranular stress corrosion cracking of austenitic stainless steels

Available data on neutron-irradiated materials have been analyzed and correlations developed between fluence, yield strength, grain boundary chromium concentration and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in critical fluence (0.2 to 2.5 n/cm{sup 2}) for IGSCC are documented.In many cases, this variability is consistent with yield strength differences among irradiated materials. IGSCC correlated better to yield strength than to fluence fo… more

Date: March 1, 1993

Creator: Bruemmer, S. M. & Simonen, E. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Post-irradiation deformation characteristics of heavy-ion irradiated 304L SS

Post-irradiation deformation behavior in Ni-ion-irradiated 304L stainless steel (SS) is examined as a function of radiation dose and deformation temperature. For similar strain levels, specimens exhibit a transition from dislocation slip to deformation-induced twinning at 25C with increasing radiation dose. At 288C twinning is no longer observed and highly localized slip occurs by the formation of narrow ``channels`` containing a reduced defect density. The observations are discussed in terms o… more

Date: June 1, 1994

Creator: Cole, J. I. & Bruemmer, S. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Mechanistic issues for modeling radiation-induced segregation

Date: March 1, 1993

Creator: Simonen, E. P. & Bruemmer, S. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation-induced segregation: A microchemical gauge to quantify fundamental defect parameters

Defect Kinetic are evaluated for austenitic stainless alloys by comparing model predictions to measured responses for radiation-induced grain boundary segregation. Heavy-ions, neutrons and proton irradiations having substantial statistical bases are examined. The combined modeling and measurement approach is shown to be useful for quantifying fundamental defect parameters. The mechanism evaluation indicates vacancy, migration energies of 1.15 eV or less and a vacancy formation energy at grain b… more

Date: December 1, 1994

Creator: Simonen, E. P. & Bruemmer, S. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Grain-boundary Chemistry, Fracture Mode and Ductility Comparison for Iron and Nickel Tested at Cathodic Potentials

The fracture mode of iron and nickel tested at equal cathodic current densities was found to be a function of the grain boundary sulfur concentration with iron and nickel having transitions at 0.12 and 0.09 monolayers of sulfur, respectively. The reduction of area of iron and nickel tested at equal cathodic current densities also decreased similarly with increasing grain boundary sulfur concentrations. The similarity in the effect of hydrogen and sulfur on iron and nickel can be explained by th… more

Date: August 1, 1980

Creator: Jones, R. H.; Bruemmer, S. M.; Thomas, M. T. & Baer, D. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Metastable phase formation in Be-Nb intermetallic compounds

Amorphous structures or metastable crystalline phases are produced in sputter-deposited Beryllium-Niobium (Be-Nb) alloys (5-15 at. % Nb) depending on the substrate temperature. The metastable phases transform to the stable Be{sub 12}Nb, Be{sub 17}Nb{sub 2}Nb phases on annealing at temperatures >800{degree}C. No Be{sub 5}Nb phase was found and the Be{sub 17}Nb{sub 2} phase is stable to low temperature. The Be{sub 12}Nb phase appeared to have a stoichiometric range of about 5.5 to 7.7 at. % Nb. T… more

Date: November 1, 1990

Creator: Brimhall, J.L.; Charlot, L.A. & Bruemmer, S.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Grain boundary chromium concentration effects on the IGSCC and IASCC of austenitic stainless steels

Comparisons are made between grain boundary composition and intergranular stress corrosion cracking (IGSCC) of 304 and 309 austenitic stainless steels in high-temperature water environments. Chromium depletion had the dominant effect on cracking resistance with the extent of IG cracking controlled by the interfacial chromium concentration. The minimum chromium concentration required to promote cracking was a function of the applied strain rate during slow-strain-rate tensile tests in 288 C air-… more

Date: August 1, 1993

Creator: Bruemmer, S. M.; Arey, B. W. & Charlot, L. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Assessment of stress-corrosion cracking in a water-cooled ITER

Water-cooled, near-term reactors will operate under conditions at which SCC is possible; however, control of material purity and processing and coolant chemistry can either eliminate or greatly reduce the probability of this type of structural failure. This evaluation has focused on an assessment of water impurity effects on SCC of austenitic stainless steel at temperatures below 100{degree}C and on the conditions controlling sensitization in the fusion heat of Type 316 SS and the fusion materi… more

Date: April 1, 1989

Creator: Jones, R. H. & Bruemmer, S. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Irradiation-assisted stress corrosion cracking considerations at temperatures below 288{degree}C

Irradiation-assisted stress corrosion cracking (IASCC) occurs above a critical neutron fluence in light-water reactor (LWR) water environments at 288 C, but very little information exists to indicate susceptibility as temperatures are reduced. Potential low-temperature behavior is assessed based on the temperature dependencies of intergranular (IG) SCC in the absence of irradiation, radiation-induced segregation (RIS) at grain boundaries and micromechanical deformation mechanisms. IGSCC of sens… more

Date: March 1, 1995

Creator: Simonen, E. P.; Jones, R. H. & Bruemmer, S. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Interfacial segregation and deformation of superplastically deformed Al-Mg-Mn alloys

Microstructural and microchemical studies have been carried out on superplastically deformed Al-Mg-Mn (AA5083-type) alloys. Grain boundary composition was measured using a Scanning Auger Microprobe (SAM) and an Analytical Transmission Electron Microscope (ATEM), while conventional TEM was used for microstructural evaluation. Non-equilibrium segregation of Si to grain boundaries following deformation was measured by both techniques. Significant interfacial Si enrichment was only detected in gage… more

Date: March 1, 1995

Creator: Vetrano, J.S.; Lavender, C.A. & Bruemmer, S.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement and modeling of radiation-induced grain boundary grain boundary segregation in stainless steels

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{degrees}C. Measured Fe, Ni, and Cr segregation increased sharply with irradiation dose (from 0 to 5 dpa) and temperature (from 175 to about 350{degrees}C). However, grain boundary concentrations did not chan… more

Date: August 1, 1995

Creator: Bruemmer, S. M.; Charlot, L. A. & Simonen, E. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effect of prior deformation on sensitization development in stainless steel during continuous cooling

Continuous cooling sensitization (CCS) occurs in austenitic stainless steel (SS) weldment HAZs where the material is subjected to weld-induced plastic deformation, and non-linear heating and cooling cycles. The primary purpose of this investigation was to quantitatively determine the effects of prior deformation on CCS. In addition, these results were used to develop a CCS data base for comparison to a recently published sensitization prediction model (SSDOS). Continuous cooling thermal cycling… more

Date: September 1, 1991

Creator: Simmons, J. W.; Atteridge, D. G. & Bruemmer, S. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Spent Fuel and Fuel Pool Component Integrity. Annual Report, FY 1980

During program FY 1980 staff members of the Spent Fuel and Fuel Pool Component Integrity Program at Pacific Northwest Laboratory (PNL) completed the following major tasks: represented DOE on the international Behavior of Fuel Assemblies in Storage (BEFAST) Committee; the program manager, A.B. Johnson, Jr., participated in an International Survey of Water Reactor Spent Fuel Storage Experience, which was conducted jointly by the International Atomic Energy Agency (Vienna) and the Nuclear Energy A… more

Date: September 1, 1981

Creator: Johnson, A. B., (Jr.); Bailey, W. J.; Bradley, E. R.; Bruemmer, S. M. & Langstaff, D. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Radiation-induced grain boundary segregation in austenitic stainless steels

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{degrees}C. Measured Fe, Ni, and Cr segregation increased sharply with irradiation dose (from G to 5 dpa) and temperature (from 175 to about 350{degrees}C). However, grain boundary concentrations did not change si… more

Date: November 1, 1994

Creator: Bruemmer, S. M.; Charlot, L. A.; Vetrano, J. S. & Simonen, E. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Defect-solute interactions near irradiation grain boundaries

Defect-solute interactions control radiation-induced segregation (RIS) to interfacial sinks, such as grain boundaries, in metallic materials. The best studied system in this regard has been austenitic stainless steels. Measurements of grain boundary composition indicate that RIS of major alloying elements are in reasonable agreement with inverse-Kirkendall predictions. The steep and narrow composition profiles are shown to result from limited back diffusion near the boundary. Subsequently, defe… more

Date: November 1, 1993

Creator: Simonen, E. P.; Vetrano, J. S.; Heinisch, H. L. & Bruemmer, S. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Effect of precipitate structure on hot deformation of Al-Mg-Mn alloys

The size and nature of precipitates have strong effects on microstructural evolution from the cold-worked state through the course of deformation at high temperatures. Through selected heat treatments and minor alloying alterations the precipitate structure of AA5083 has been manipulated. Minor additions of Zr have been used to create fine (50 to 100 nm) precipitates. The number and size distribution of medium-sized (<1 {mu}m) Mn-rich precipitates were modified by increasing the Mn concentratio… more

Date: October 1, 1993

Creator: Vetrano, J. S.; Lavender, C. A.; Smith, M. T. & Bruemmer, S. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Irradiation-assisted stress corrosion cracking of fusion reactor material

Irradiation-assisted stress-corrosion cracking (IASCC) is a phenomenon produced by radiation-induced alterations in the material and environment. These alternations include radiation-induced segregation and depletion of specific elements at grain boundaries, radiation creep and hardening and radiolytic effects induced in the aqueous environment. This phenomenon has been clearly identified as an active crack growth mechanism for in-core components in fission reactor must be considered as a poten… more

Date: August 1, 1990

Creator: Jones, R. H.; Simonen, E. P. & Bruemmer, S. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Temperature and strain-rate effects on deformation mechanisms in irradiated stainless steel

Analysis of the deformation microstructures in ion-irradiated stainless steel shows twinning to be the predominant deformation mode at room temperature. Dislocation channelling also occurs under slow strain rate conditions. Stresses required for twinning were calculated by the model of Venables and are compatible with observed yield stresses in neutron-irradiated material if loops are the principal twin source. Computation of the expected radiation hardening from the defect structure, based on … more

Date: November 1, 1994

Creator: Brimhall, J. L.; Cole, J. I.; Vetrano, J. S. & Bruemmer, S. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Phase stability in Be-Nb and Be-Nb-Zr intermetallics

Sputter deposition of Be-Nb alloys at low temperature (30{degrees}C) produces an amorphous phase for compositions >5 at.% Nb. A metastable crystalline phase which can be considered a highly faulted form of the Be{sub 12}Nb occurs at higher deposition temperatures or by low-temperature annealing of the amorphous phase. Because of structural similarities, this metastable phase is a precursor to the formation of either Be{sub 12}Nb or Be{sub 17}Nb{sub 2} upon high temperature annealing. There was … more

Date: September 1, 1991

Creator: Brimhall, J.L.; Charlot, L.A. & Bruemmer, S.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Irradiation effects on the electrochemistry and corrosion resistance of stainless steel

Nickel-ion irradiation at 500{degrees}C is shown to have a strong effect on the surface electrochemistry and intergranular corrosion of stainless steel. Measured current densities in a 1N H{sub 2}SO{sub 4} solution at room temperature are increased at active-passive, passive, and transpassive potentials. Irradiation effects on the current decay behavior and susceptibility to intergranular corrosion were similar for a microcrystalline, fine-grained stainless alloy and for a very large-grained st… more

Date: April 1, 1992

Creator: Bruemmer, S. M.; Arey, B. W.; Windisch, C. F., Jr. & Cole, J. I.

Item Type: Article

Partner: UNT Libraries Government Documents Department