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Progress in passive solar energy systems. Volume 8. Part 1

Description: This book presents the papers given at a conference sponsored by the US DOE, the Solar Energy Research Institute, SolarVision, Inc., and the Southern California Solar Energy Society. The topics considered at the conference included sizing solar energy systems for agricultural applications, a farm scale ethanol production plant, the EEC wind energy RandD program, the passive solar performance assessment of an earth-sheltered house, the ARCO 1 MW photovoltaic power plant, the performance of a dendritic web photovoltaic module, second generation point focused concentrators, linear fresnel lens concentrating photovoltaic collectors, photovoltaic conversion efficiency, amorphous silicon thin film solar cells, a photovoltaic system for a shopping center, photovoltaic power generation for the utility industry, spectral solar radiation, and the analysis of insolation data.
Date: January 1, 1983
Creator: Hayes, J. & Andrejko, D.A.

Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Paducah Gaseous Diffusion Plant site

Description: Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. The U-235 atoms are ionized when precisely tuned laser light -- of appropriate power, spectral, and temporal characteristics -- illuminates the uranium vapor and selectively photoionizes the U-235 isotope. A programmatic document for use in screening DOE site to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the PGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. 65 refs., 15 tabs.
Date: September 1, 1991
Creator: Marmer, G.J.; Dunn, C.P.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Yuen, C.R. et al.

EOCR building wake effects on atmospheric diffusion. Technical memo

Description: A series of 22 simultaneous releases of three gaseous tracers was conducted around the EOCR test reactor building at the Idaho National Engineering Laboratory in SE Idaho. Hourly average gaseous tracer concentrations were sampled on several concentric sampling arcs and at a limited number of elevated locations. Winds and temperatures were measured on a nearby 30mm tower. Complete data appendices provide tracer concentration measurements, temperatures, winds and detailed wind statistics, derived diffusion statistics, and plots and analyses.
Date: January 1, 1981
Creator: Start, G.E.; Hukari, N.F.; Sagendorf, J.F.; Cate, J.H. & Dickson, C.R.

Safety approach to the selection of design criteria for the CRBRP reactor refueling system

Description: The selection of safety design criteria for Liquid Metal Fast Breeder Reactor (LMFBR) refueling systems required the extrapolation of regulations and guidelines intended for Light Water Reactor refueling systems and was encumbered by the lack of benefit from a commercially licensed predecessor other than Fermi. The overall approach and underlying logic are described for developing safety design criteria for the reactor refueling system (RRS) of the Clinch River Breeder Reactor Plant (CRBRP). The complete selection process used to establish the criteria is presented, from the definition of safety functions to the finalization of safety design criteria in the appropriate documents. The process steps are illustrated by examples.
Date: January 1, 1979
Creator: Meisl, C J; Berg, G E & Sharkey, N F

On the cells of origin of radiogenic thyroid cancer: New studies based on an old idea

Description: We have presented evidence that the functional thyroid follicles (follicular units, FU) which are formed in grafts of monodispersed rat thyroid cells, and hence the thyroid tumors which later develop in such grafts, are clonal in origin. Recent studies have been designed to investigate: whether cell number-dependent inhibition of promotion-progression is mediated by remote hormonal feed-back, local cell-cell interactions, or both; the cell population kinetics of the clonogen subpopulation during goitrogenesis and goiter involution; and the effect of prolonged exposure to high levels of TSH (thyrotropin) on the capacity of the clonogens to give rise to functional FU. The results indicate that local cell-cell interactions play an important role in the cell number-dependent suppression of neoplastic promotion-progression. They also show that if sufficient thyroid cells are grafted, the thyroid-pituitary axis can be reestablished in thyroidectomized rats fed normal diets. In such animals given iodine deficient diets, the FU that develop in the thyroid grafts shift their secretory pattern to increase the ratio of T3 (triiodothyronine) to T4 (thyroxine), and thus conserve the available iodine. Finally, the clonogenic subpopulation is conserved during both goitrogenesis and goiter involution. When they are transplanted to thyroidectomized recipients, clonogens from two types of goiters form FU that are morphologically indistinguishable from those that develop in grafts of normal thyroid clonogens. Furthermore, the secretion of T3 and T4 by such grafts is dependent on the grafted clonogen number, and hence FU formation, and not on the total number of thyroid cells transplanted. We conclude that the thyroid clonogens, the presumptive cancer progenitor cells, have many of the characteristics of stem cells.
Date: January 1, 1990
Creator: Clifton, K.H.; Domann, F.E. & Groch, K.M.

Reactor physics input to the safety analysis report for the High Flux Isotope Reactor

Description: HFIR specific, few group neutron and coupled neutron-gamma libraries have been prepared. These are based on data from ENDF/B-V and beginning-of-life (BOL) conditions. The neutron library includes actinide data for curium target rods. Six critical experiments, collectively designated HFIR critical experiment 4, were analyzed. Calculated k-effective was 2% high at BOL-typical conditions but was 1.0 at end-of-life-typical conditions. The local power density distributions were calculated for each of the critical experiments. The axially averaged values at a given radius were frequently within experimental error. However at individual points, the calculated local power densities were significantly different from the experimentally derived values (several times greater than experimental uncertainty). A reassessment of the foil activation data with transport theory techniques seems desirable. Using the results of the critical experiments study, a model of current HFIR configuration was prepared. As with the critical experiments, BOL k-effective was high (3%). However, end-of-life k-effective was high (2%). The end-of-life concentrations of fission products were compared to those generated using the ORIGEN code. Agreement was generally good through differences in the inventories of some important nuclides, Xe and I, need to be understood. End-of-cycle curium target isotopics based on measured, discharged target rods were compared to calculated values and agreement was good. Axial flux plots at various irradiation positions were generated. Time-dependent power distributions based on two-dimensional calculations were provided.
Date: March 1, 1992
Creator: Primm, R.T. III.

Radiation resistance testing of high-density polyethylene. [Gamma rays]

Description: Mechanical tests following gamma inrradiation and creep tests during irradiation have been conducted on high-density polyethylene (HDPE) to assess the adequacy of this material for use in high-integrity containers (HICs). These tests were motivated by experience in nuclear power plants in which polyethylene electrical insulation detoriorated more rapidly than expected due to radiation-induced oxidation. This suggested that HDPE HICs used for radwaste disposal might degrade more rapidly than would be expected in the absence of the radiation field. Two types of HDPE, a highly cross-linked rotationally molded material and a non-cross-linked blow molded material, were used in these tests. Gamma-ray irradiations were performed at several dose rates in environments of air, Barnwell and Hanford backfill soils, and ion-exchange resins. The results of tensile and bend testing on these materials following irradiation will be presented along with preliminary results on creep during irradiation.
Date: January 1, 1983
Creator: Dougherty, D.R. & Adams, J.W.

Selected data from thermal-spring areas, southwestern Montana

Description: During 1975 to 1977 the Montana district of the US Geological Survey collected and assembled data describing the flow, temperature, and chemical characteristics of thermal and related waters. The work was part of an assessment of the geothermal resources of southwestern Montana, excluding Yellowstone Park. Representative data are presented here from 24 thermal springs and 3 deep wells where water temperatures exceed 38/sup 0/C (100/sup 0/F). Initially, the data base included references reported by Waring (1965). The data base also included unpublished chemical analyses of water samples and related data collected during 1959 to 1973 by the Montana State Board of Health (now Montana Department of Health and Environmental Sciences), the Montana Bureau of Mines and Geology, and by graduate students for theses. Results of analyses and engineering reports were collected from landowners, and additional published and unpublished data were collected by Geological Survey investigators during 1967 to 1975. Tabulation of the data revealed wide discrepancies in reported parameters for some sites. Inadequate description of the sampling sites limited the value of much of the previously reported data, because most of the thermal springs were characterized by multiple outlets. Field measurements of rate, specific conductance, pH, and temperature of flow at the various outlets, particularly those having the highest temperatures, were compared with previously reported determinations.
Date: May 1, 1978
Creator: Leonard, R.B.; Brosten, T.M. & Midtlyng, N.A.

Surface effects on sputtered atoms and their angular and energy dependence

Description: A comprehensive three-dimensional Monte Carlo computer code, Ion Transport in Materials and Compounds (ITMC), has been developed to study in detail the surfaces related phenomena that affect the amount of sputtered atoms and back-scattered ions and their angular and energy dependence. A number of important factors that can significantly affect the sputtering behavior of a surface can be studied in detail, such as having different surface properties and composition than the bulk and synergistic effects due to surface segregation of alloys. These factors can be important in determining and lifetime of fusion reactor first walls and limiters. The ITMC Code is based on Monte Carlo methods to track down the path and the damage produced by charged particles as they slow down in solid metal surfaces or compounds. The major advantages of the ITMC code are its flexibility and ability to use and compare all existing models for energy losses, all known interatomic potentials, and to use different materials and compounds with different surface and bulk composition to allow for dynamic surface composition to allow for dynamic surface composition changes. There is good agreement between the code and available experimental results without using adjusting parameters for the energy losses mechanisms. The ITMC Code is highly optimized, very fast to run and easy to use.
Date: April 1, 1985
Creator: Hassanein, A.M.

Summary of the research and development effort on open-cycle coal-fired gas turbines

Description: Extensive experience gained with gas turbines operating not only with coal as fuel but also with dusty inlet air and with dirty fuels (such as heavy oils and blast furnace gas) as well as petroleum catalytic cracking units was reviewed. All this experience indicates that the particulate content of the hot gases fed to the turbine must be kept to less than approx. 1 ppM to keep turbine bucket erosion to an acceptable level for turbine inlet temperatures of 1500/sup 0/F or more. Dropping the turbine inlet temperature below 1110/sup 0/F makes it possible to obtain turbine bucket lives of around 3 yr with approx. 100 ppM of particulates if a number of compromises are made in the turbine design. A buildup of deposits in the turbine is a serious problem if sulfates or chlorides are present in the gas stream and the turbine inlet temperature is above approx. 1110/sup 0/F. At this temperature level, these materials become soft and sticky and form films on the blades that accumulate deposits of the silicates and oxides present in the ash of a coal-fired combustor. Extensive experience with many types of cyclone separators shows that they can be used to reduce the particulate content to as low as approx. 100 ppM under the best conditions. Granular bed filters have yielded similar performance. Electrostatic precipitators are not effective above approx. 1110/sup 0/F because the dust deposits on insulators become conducting and short out the grids. The only effective way found to reduce the particulate content of blast furnace gas and gas from coal gasification units to the approx. 1 ppM required for a high-temperature gas turbine is to cool the gas and pass it through a two-stage water scrubber or equivalent before burning it. In brief, it appears doubtful that any of the ...
Date: October 1, 1979
Creator: Lackey, M.E.

What can be learned with fast neutrons

Description: The DOE/NSF Nuclear Science Advisory Committee (NSAC) is preparing a new Long Range Plan for the development of nuclear science. This document, written as input to the Long Range Plan subcommittees; describes a number of ways that experiments with incident neutrons impact on outstanding problems in nuclear reactions and spectroscopy. It is argued that major extensions of present capabilities are required to carry out these experiments.
Date: June 1, 1983
Creator: Dietrich, F.S.

West Hackberry Strategic Petroleum Reserve site brine-disposal monitoring, Year I report. Volume IV. Bibliography and supporting data for physical oceanography. Final report. [421 references]

Description: This project centers around the Strategic Petroleum Site (SPR) known as the West Hackberry salt dome which is located in southwestern Louisiana and which is designed to store 241 million barrels of crude oil. Oil storage caverns are formed by injecting water into salt deposits, and pumping out the resulting brine. Studies described in this report were designed as follow-on studies to three months of pre-discharge characterization work, and include data collected during the first year of brine leaching operations. The objectives were to: (1) characterize the environment in terms of physical, chemical and biological attributes; (2) determine if significant adverse changes in ecosystem productivity and stability of the biological community are occurring as a result of brine discharge; and (3) determine the magnitude of any change observed. Volume IV contains the following: bibliography; appendices for supporting data for physical oceanography, and summary of the physical oceanography along the western Louisiana coast.
Date: February 1, 1983
Creator: DeRouen, L.R.; Hann, R.W.; Casserly, D.M.; Giammona, C. & Lascara, V.J. (eds.)

X-ray microscopy using grazing-incidence reflections optics

Description: The role of Kirkpatrick-Baez microscopes as the workhorse of the x-ray imaging devices is discussed. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics.
Date: June 30, 1983
Creator: Price, R.H.

Cooling-load implications for residential passive-solar-heating systems

Description: Ongoing research on quantifying the cooling loads in residential buildings, particularly buildings with passive solar heating systems, is described, along with the computer simulation model used for calculating cooling loads. A sample of interim results is also presented. The objective of the research is to develop a simple analysis method, useful early in design, to estimate the annual cooling energy requirement of a given building.
Date: January 1, 1983
Creator: Jones, R.W. & McFarland, R.D.

Hanford Site ground-water monitoring for January through June 1988

Description: The Pacific Northwest Laboratory monitors ground-water quality at the Hanford Site for the US Department of Energy to assess the impact of Site operations on the environment. Work undertaken between January and June 1988 included monitoring ground-water elevations across the Site, and monitoring hazardous chemicals and radionuclides in ground water. Water levels continued to rise in areas receiving increased recharge (e.g., beneath B Pond) and decline in areas where the release of water to disposal facilities has been terminated (e.g., U Pond). The major areas of ground-water contamination defined by monitoring activities are (1) carbon tetrachloride in the 200-West Area; (2) cyanide in and north of the 200-East and 200-West Areas; (3) hexavalent chromium contamination in the 100-B, 100-D, 100-F, 100-H, 100-K, and 200-West Areas; (4) chlorinated hydrocarbons in the vicinity of the Solid Waste Landfill and 300 Area; (5) uranium in the 100-F, 100-H, 200-West, and 300 Areas; and (6) tritium and nitrate across the Site. In addition, several new analytical initiatives were undertaken during this period. These include cyanide speciation in the BY Cribs plume, inductively coupled argon plasma/mass spectrometry (ICP/MS) measurements on a broad selection of samples from the 100, 200, 300, and 600 Areas, and high sensitivity gas chromatography measurements performed at the Solid Waste Landfill-Nonradioactive Dangerous Waste Landfill. 23 figs., 25 tabs.
Date: May 1, 1989
Creator: Evans, J.C.; Bryce, R.W. & Sherwood, D.R.

Recent improvements in beam diagnostic instrumentation

Description: In high-current machines, such as LAMPF and the envisioned Hanford Engineering Development Laboratory (HEDL) Fusion Materials Irradiation Test (FMIT) Facility linac, hands-on maintenance is desired Beam spill must be kept extremely low; therefore, attention must be given to beam fringes (tails). Beam matching to the structure becomes increasingly important. Equipment capable of accurately measuring transverse beam profiles over a range spanning more than four orders of magnitude and longitudinal phase profiles over ranges spanning more than three orders of magnitude is described. Errors in 100-MeV transverse emittance measurements are explored and experimental emittance measurements made with three different methods are compared. Advantages of one nondestructive method are developed.
Date: January 1, 1979
Creator: Sander, O.R.; Jameson, R.A. & Patton, R.D.

Aquatic Pathways Model to predict the fate of phenolic compounds. Appendixes A through D

Description: Organic materials released from energy-related activities could affect human health and the environment. We have developed a model to predict the fate of spills or discharges of pollutants into flowing or static bodies of fresh water. A computer code, Aquatic Pathways Model (APM), was written to implement the model. The APM estimates the concentrations of chemicals in fish tissue, water and sediment, and is therefore useful for assessing exposure to humans through aquatic pathways. The major pathways considered are biodegradation, fish and sediment uptake, photolysis, and evaporation. The model has been implemented with parameters for the distribution of phenols, an important class of compounds found in the water-soluble fractions of coal liquids. The model was developed to estimate the fate of liquids derived from coal. Current modeling efforts show that, in comparison with many pesticides and polyaromatic hydrocarbons (PAH), the lighter phenolics (the cresols) are not persistent in the environment. For the twelve phenolics studied, biodegradation appears to be the major pathway for elimination from aquatic environments. A pond system simulation of a spill of solvent-refined coal (SRC-II) materials indicates that phenol, cresols, and other single cyclic phenolics are degraded to 16 to 25 percent of their original concentrations within 30 hours. Adsorption of these compounds into sediments and accumulation by fish was minor. Results of a simulated spill of a coal liquid (SRC-II) into a pond show that APM predicted the allocation of 12 phenolic components among six compartments at 30 hours after a small spill. The simulation indicated that most of the introduced phenolic compounds were biodegraded. The phenolics remaining in the aquatic system partitioned according to their molecular weight and structure. A substantial amount was predicted to remain in the water, with less than 0.01% distributed in sediment or fish.
Date: April 1, 1983
Creator: Aaberg, R.L.; Peloquin, R.A.; Strenge, D.L. & Mellinger, P.L.

Calculated k-effectives for plutonium critical experiments. Consolidated Fuel Reprocessing Program

Description: Design criteria for a reprocessing facility for Liquid Metal Fast Breeder Reactor fuel are presently being developed. One major issue of concern is the criticality safety of all equipment (dissolver, centrifuge, holding tanks, etc.) that is used to contain the plutonium solution. The purpose of this work is to evaluate the validity of the SCALE code system for application to plutonium systems when used with cross section data from the 27-group ENDF/B-IV and 16-group Hansen-Roach libraries (available in SCALE). Previous work has been done in this area, but it was limited to one-dimensional discrete ordinates calculations. Twelve sets of critical plutonium experiments yielding a total of thirty-eight computational models are considered. The experiments were performed in spherical, cylindrical, and slab geometries covering a wide range of fuel composition. The hydrogen-to-plutonium atom ratio varied from 3695 for an infinite dilute system to 0.04 for damp, plutonium oxide polystyrene experiments. The SCALE system employs several codes for criticality calculations, but only two are used in this work. Criticality Safety Analysis Sequence Number 1 (CSAS1) uses discrete ordinates theory to calculate k-eff, and its application is limited to one-dimensional calculations. Criticality Safety Analysis Sequence Number 2 (CSAS2) uses Monte Carlo methods to calculate k-eff, and its application includes three dimensional systems. Calculated results of the 38 models using both cross sections libraries are presented. The calculated k-effectives vary from a high of 1.04119 +- 4.87E-3 to a low of 0.99458 +- 4.66E-3. The majority of the k-effectives vary between 1.01 and 1.03 illustrating a systematic overestimation of k-eff. Some of the one dimensional experiments were modeled with both CSAS1 and CSAS2 to see if the calculated k-effectives show any significant dependency on the code used.
Date: January 1, 1984
Creator: Easter, M.E.; Dodds, H.L. & Primm, R.T. III

Comparison of the SASSYS/SAS4A radial core expansion reactivity feedback model and the empirical correlation for FFTF

Description: The present emphasis on inherent safety for LMR designs has resulted in a need to represent the various reactivity feedback mechanisms as accurately as possible. The dominant negative reactivity feedback has been found to result from radial expansion of the core for most postulated ATWS events. For this reason, a more detailed model for calculating the reactivity feedback from radial core expansion has been recently developed for use with the SASSYS/SAS4A Code System. The purpose of this summary is to present an extension to the model so that it is more suitable for handling a core restraint design as used in FFTF, and to compare the SASSYS/SAS4A results using this model to the empirical correlation presently being used to account for radial core expansion reactivity feedback to FFTF.
Date: January 1, 1987
Creator: Wigeland, R.A.

Electric power monthly, January 1991. [Contains glossary]

Description: This publication provides monthly statistics at the national, Census division, and state levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and average revenue per kilowatthour of electricity sold. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel. 4 figs., 48 tabs.
Date: January 17, 1991
Creator: Available, Not

Environmental report for calendar year 1989

Description: This report gives the results of the environmental activities and monitoring programs at the Princeton Plasma Physics Laboratory (PPPL) for Calendar Year 1989 (CY89). The report is prepared to provide the US Department of Energy (DOE) and the public with information on the level of radioactive and nonradioactive pollutants, if any, added to the environment as a result of PPPL operations. The objective of the environmental report is to document evidence that DOE facility environmental protection programs adequately protect the environment and the public health. During CY89, there were no accidents, incidents, or occurrences that had a significant impact on PPPL facilities or program operations. The accidental overfilling of an underground storage tank (UST) during 1988, along with the discovery of residual hydrocarbons in the soil of an area used for unloading fuel oil trucks over the last 30 years, has the potential for a minor environmental impact and has resulted in a costly clean up in this area. Surface water analyses for both radioactive and nonradioactive pollutants have shown nothing above normally expected background values. Ambient tritium levels at less than 100 pCi/liter (3.7 Bq/liter) were measured in D-site well water. New groundwater monitoring wells were added in 1989 as a requirement for the groundwater part of our New Jersey Pollutant Discharge Elimination System (NJPDES) permit. Initial sampling of these wells indicated the presence of lead in two shallow wells next to the detention basin. Radiation exposure via airborne effluents into the environment is still at insignificant levels; however, a stack monitor for tritium is planned for 1990 to ensure compliance with new EPA regulations. Off-site surface water, soils, and biota continued to be analyzed for radioactive baselines in CY89. 51 refs., 27 figs., 40 tabs.
Date: March 1, 1991
Creator: Stencel, J.R. & Turrin, R.P.

California Basin study (CaBS): DOE west coast basin program

Description: The overall objective of our research continues to be elucidation of the transport pathways and transformations of organic matter in the California Basins region, with particular reference to the role of macrozooplankton in upper waters. We have concentrated on C and N pathways and fluxes to data, and will continue to investigate these further (seasonal aspects, and the role of zooplankton carnivory in zooplankton-medicated C and N flux, for example).
Date: January 1, 1990
Creator: Small, L.F.

Computation of invariant tori in 2 1/2 degrees of freedom

Description: Approximate invariant tori in phase space are found using a non-perturbative, numerical solution of the Hamilton-Jacobi equation for a nonlinear, time-periodic Hamiltonian. The Hamiltonian is written in the action-angle variables of its solvable part. The solution of the Hamilton-Jacobi equation is represented as a Fourier series in the angle variables but not in the time' variable. The Fourier coefficients of the solution are regarded as the fixed point of a nonlinear map. The fixed point is found using a simple iteration or a Newton-Broyden iteration. The Newton-Broyden method is slower than the simple iteration, but it yields solutions at amplitudes that are significant compared to the dynamic aperture.' Invariant tori are found for the dynamics of a charged particle in a storage ring with sextupole magnets. 10 refs., 3 figs., 3 tabs.
Date: January 1, 1991
Creator: Gabella, W.E. (Colorado Univ., Boulder, CO (USA). Dept. of Physics); Ruth, R.D. & Warnock, R.L. (Stanford Linear Accelerator Center, Menlo Park, CA (USA))

Phase formation at bonded vanadium and stainless steel interfaces

Description: The interface between vanadium bonded to stainless steel was studies to determine whether a brittle phase formed during three joining operations. Inertia friction welds between V and 21-6-9 stainless steel were examined using TEM. In the as-welded condition, a continuous, polygranular intermetallic layer about 0.25 {mu}m thick was present at the interface. This layer grew to about 50 {mu}m thick during heat treatment at 1000{degrees}C for two hours. Analysis of electron diffraction patterns confirmed that this intermetallic was the {omega} phase. The interface between vanadium and type 304, SANDVIK SAF 2205, and 21-6-9 stainless steel bonded by a co-extrusion process had intermetallic particles at the interface in the as-extruded condition. Heat treatment at 1000{degrees}C for two hours caused these particles to grow into continuous layers in all three cases. Based on the appearance, composition and hardness of this interfacial intermetallic, it was also concluded to be {omega} phase. Bonding V to type 430 stainless steel by co-extrusion caused V-rich carbides to form at the interface due to the higher concentration of C in the type 430 than in the other stainless steels investigated. The carbide particles initially present grew into a continuous layer during a two-hour heat treatment at 1000{degrees}C. Co-hipping 21-6-9 stainless steel tubing with V rod resulted in slightly more concentric specimens than the co-extruded ones, but a continuous layer of the {omega} phase formed during the hipping operation. This brittle layer could initiate failure during subsequent forming operations. The vanadium near the stainless steel interface in the co-extruded and co-hipped tubing in some cases was harder than before heat treatment. It was concluded that this hardening was due to thermal straining during cooling following heat treatment and that thermal strains might present a greater problem than seen here when longer tubes are used in actual applications.
Date: January 1, 1992
Creator: Summers, T.S.E.