bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tube-Burst Response of Irradiated Zircaloy Spent-Fuel Cladding
Authors: Bauer AA , Lowry LM , Gallagher WJ 
Published: March 2009

Transient-heating tube-burst tests were conducted on a 50.8-cm length of Zircaloy cladding obtained from spent-fuel rods irradiated in the H. B. Robinson power reactor to a peak burn-up of 30 MWD/kg. Internal electrical resistance heaters were used to achieve nominal heating rates of 28°C/s for the tests. The tests were conducted in steam and the independent experimental variable was the initial level of helium pressurization.
Tube burst pressures varied from 0.965 to 12.514 MPa. Corresponding burst stresses and temperatures varied from 7.5 MPa and 1135°C to 99.1 MPa and 734°C, respectively. Failure strains ranged up to 46 percent when burst occurred at upper (α + β) and β-phase temperatures and up to 30 percent for failures occurring at lower temperatures.
No significant difference in burst behavior between unirradiated and spent nuclear fuel Zircaloy cladding was observed experimentally. No influence of axial restraint on burst strains was noted.
Effect of Oxygen on the Deformation of Zircaloy-2 at Elevated Temperatures
Authors: Rizkalla AS , Holt RA , Jonas JJ 
Published: March 2009

During some hypothetical loss-of-coolant accidents (LOCA), Zircaloy fuel sheathing is expected to reach temperatures in excess of 1273 K and to oxidize rapidly. The objective of the current work was to determine the effect of oxygen on the mechanical behavior of Zircaloy-2 at temperatures above 1273 K.
Zircaloy-2 containing 1 200, 4 000, 8 000, and 12 000 ppm oxygen was deformed in compression at 1275, 1375, and 1475 K at constant true strain rates of 10-4 to 10-1 s-1. The flow stress of Zircaloy-2 increases by a factor of 3 to 4 as the oxygen concentration is increased from 1200 to 12 000 ppm. Approximately half of this increase is due to solid solution strengthening by oxygen and approximately half to the effect of oxygen on the volume fraction of the much stronger α-zirconium. The stress exponent of the strain rate of both phases appears to be unaffected by oxygen, being 3.5 to 4.0 for β-zirconium and 5 to 6 for α-zirconium. In the (α + β)-phase field, the stress sensitivity at low strain rates is low, suggesting that some form of boundary sliding mechanism contributes to flow.
The stress-strain curves are either “normal” flow curves, with work hardening and saturation of the flow stress, or “abnormal” flow curves, in which a maximum or peak stress is reached at low strains, followed by flow softening. The flow stress peaks are attributed to an aging or clustering effect that occurs when the α phase is enriched in iron and chromium, and the flow softening is attributed to strain-enhanced declustering or coarsening of the precipitates.
Interaction of Oxidation and Creep in Zircaloy-2
Authors: Burton B , Donaldson AT , Reynolds GL 
Published: March 2009

In the event of a loss-of-coolant accident in water-cooled reactors, the Zircaloy-2 cladding is subjected to a rapid increase in temperature and stress in an oxidizing environment. Accurate numerical values of creep parameters are thus required for use in tube deformation models that predict fuel cladding behavior during such an accident. Also, it is necessary to know quantitatively the effect of oxidation on creep behavior.
Creep tests have been performed in the temperature range 1000 to 1925 K on Zircaloy-2. In this temperature range, the material undergoes a phase transformation from α to β phase at ∼1100 K. Tensile creep results on these two phases have been performed in vacuum. The α-phase material was tested in strip form in a conventional creep machine, although to obtain data at high temperatures in the β phase, resistance-heated wire specimens were used. The creep of both the α and β phases of Zircaloy in the unoxidized condition can be satisfactorily represented by the Dorn equation for dislocation creep controlled by lattice diffusion:ε˙i=AiGibikT(σGi)niDiwhere i = α, β and the creep parameters Ai and ni take the values:Aα=1.67×1011Aβ=0.6nα=5.36nβ=3.7
Further experiments are reported on the influence of oxygen on creep. The first series of experiments on material with oxygen in uniform solid solution indicate that oxygen has no effect on the creep of β-phase material until the solubility limit of oxygen is reached. However, the creep of α-phase material is significantly modified by the presence of dissolved oxygen. Creep rate is shown to decrease according to the expressionε˙=ε˙0exp⁡(−βC)where ε˙0 is the creep rate of Zircaloy-2 containing no dissolved oxygen, β is a constant at a given stress and temperature, and C is the oxygen concentration. Numerical values of β are discussed in the text.
Creep of duplex α + β phase is also investigated using techniques both of equilibrating the structure at test temperature before testing and also admitting measured quantities of oxygen during test. Using these techniques combined with experiments at different temperatures permits a wide range of structures to be obtained and transient effects to be observed. The relationships between the different morphologies of the duplex material, the relative proportions of the two phases, and creep behavior are discussed.
Grain boundary sliding in β-phase Zircaloy-2 is also investigated. The rate of sliding is shown to vary, with stress raised to a power slightly greater than unity with an activation energy close to that for lattice diffusion, and results are interpreted in terms of sliding controlled by diffusion between undulations in the boundary geometry. The geometry required to satisfy the observed rates of sliding is estimated. It is shown that oxygen has no effect on sliding, although nitriding inhibits sliding.
Field Validation of Water Quality Criteria for Hydrophobic Pollutants
Authors: Schnoor JL 
Published: March 2009

A comparison of laboratory and field bioconcentration factors (BCFs) is made for a variety of hydrophobic pollutants, including dieldrin, dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDD), dichlorodiphenyldichloroethylene (DDE), chlordane, polychlorinated biphenyl (PCB), and heptachlor epoxide. The bioconcentration factors calculated from field data in Iowa rivers, the Coralville Reservoir in Iowa, Lake Ontario, and Lake Superior are within a factor of 1 to 4 of laboratory-derived bioconcentration factors in the fat of fish. The U.S. Environmental Protection Agency's water quality criteria are also within a factor of 1 to 4 of estimated field concentrations which would result in a maximum permissible tissue concentration (MPTC). Field bioconcentration factors normalized on a fat or oil basis correlate with the octanol-water partition coefficient of 13 hydrophobic pollutants.
Bioconcentration data were utilized in a mathematical model to calculate the fate and transport of dieldrin in the Coralville Reservoir. The author demonstrates that laboratory-derived BCFs can be used in fate and effects modeling with order-of-magnitude results or better.
Use of the Hazard Assessment Approach for Evaluating the Impact of Chlorine and Ammonia in Pueblo, Colorado, Domestic Wastewaters on Water Quality in the Arkansas River
Authors: Lee GF , Jones RA , Newbry BW , Heinemann TJ 
Published: March 2009

A short-term, intensive study has been conducted on the potential impact of the chlorine, and to a lesser extent the ammonia and nitrite, associated with the domestic wastewater discharge from the city of Pueblo, Colo. on the water quality (beneficial uses) of the Arkansas River downstream from the discharge. The hazard assessment approach was used in the planning of the study and in data interpretation.
The wastewater treatment plant (WWTP) effluent mixed slowly with the river, forming a narrow effluent plume extending downstream for about 1000 m; in this “zone of mixing” contaminant concentrations were sufficient to kill caged fathead minnows in 4 days or less. A continuous “zone of passage” existed past the discharge in which no visually apparent adverse effects on caged fish were found in 4 days' exposure.
Chlorine concentration decreased with the distance downstream of the discharge, but, based on the concentrations found, there is a potential for chlorine impact on aquatic life for a distance of about 15 km. Outside the zone of physical mixing of the effluent and the river, nitrite and un-ionized ammonia concentrations were below the corresponding Colorado water quality guidelines; however, questions regarding their impact on the water quality within this zone were raised and need to be addressed in future studies.
Microstructures Versus Properties of 29-4 Ferritic Stainless Steel
Authors: Aggen G , Deverell HE , Nichol TJ 
Published: March 2009

The subject of this investigation is a low interstitial 29Cr-4Mo ferritic stainless steel developed and patented by E.I. duPont de Nemours and Co., Inc. The alloy, commonly known as 29-4, is characterized by exceptionally high resistance to chloride pitting and stress corrosion cracking and by comparatively good room temperature toughness and ductility.
Sheet specimens from a commercial heat were exposed for times up to 100 h at temperatures from 371 to 982°C (700 to 1800°F). Metallographic changes that were observed were correlated to changes in impact and tensile properties, crevice corrosion in ferric chloride, and intergranular corrosion resistance in ferric sulfate-sulfuric acid. Excess phase identifications and studies of failure modes were conducted on selected samples.
Two embrittlement regions were found centered at about 482°C (900°F) and 760°C (1400°F). The lower temperature embrittlement region is quite narrow and was ascribed to 475°C (885°F) embrittlement. No deterioration in corrosion resistance was detected in this embrittlement region. Embrittlement occurred much more rapidly in the higher temperature region and existed over a wide temperature range. Crevice corrosion resistance and corrosion resistance to ferric sulfate- sulfuric acid deteriorated rapidly in this embrittlement region. Changes in mechanical properties and corrosion resistance upon heat treating in the region were ascribed primarily to the precipitation of sigma and chi phases.
Super Waspaloy Microstructure and Properties
Authors: Deye DJ , Couts WH 
Published: March 2009

Waspaloy is currently one of the more widely used alloys for turbine disk applications in the aerospace industry. However, higher engine performance demands by aircraft engine manufacturers have resulted in a number of approaches by material suppliers to upgrade the alloy. These approaches range from simple compositional modifications to a combination of chemistry modifications coupled with thermal mechanical processing. One such approach resulted in what is now commonly referred to as Super Waspaloy.
Tension, low-cycle fatigue, and creep rupture tests of Waspaloy and Super Waspaloy forgings were conducted from room temperature to 1089 K (1500°F), after which material properties were reviewed and correlated with the disk microstructure.
Microstructure and Mechanical Properties of INCOLOY Alloy 800 After 14 Years of Service as a Catalyst Tube in a Steam-Methane Reformer
Authors: Mankins WL , Wenschhof DE 
Published: March 2009

An INCOLOY Alloy 800 catalyst tube, which served satisfactorily in a steam-methane reformer for more than 14 years, was removed for examination. The tube had been heated to temperatures varying along its length from 540 to 815°C (1000 to 1500°F).
The deepest penetration of intergranular oxidation was only 0.33 mm (0.013 in.) on the outer surface.
Room-temperature tensile properties and stress-rupture properties improved significantly with the precipitation of carbides at higher temperatures and gamma prime at the lower temperatures. Gamma prime was the principal strengthening phase, and mechanical properties show that ductility was retained.
Rare, discrete, blocky particles of sigma phase found in one section of the tube were determined to be innocuous.
Adhesion of Steel Tire Cord to Rubber Compounds Mutual Influence of Brass and Rubber Compounds on the Adhesion
Authors: Bourrain MP 
Published: March 2009

A study was made on strands to define the evolution of the original adhesion as well as thermic aging adhesion both under and free from moisture conditions. The following parameters have been recorded: composition of brass, brass thickness and the formulations of calendered rubber compounds that are representative of the compounds found in tire manufacturing.
The resulting graphic curves show a displacement of maximal adhesion depending essentially on the copper content, on the adhesion promoters used in rubber compounds (cobalt salt or resorcinol-silica-hexamethylene tetramine system), and on the sulfur content with as much regard to the original adhesion as to the aging adhesion.
The influence of the brass plating thickness agrees with the results of a study made on the diffusion of sulfur in brass by the means of X-ray photoelectron spectroscopy [XPS or electron spectroscopy for chemical analysis (ESCA)].
Degradation of Adhesion of Coated Tire Cords to Rubber by Atmospheric Pollutants
Authors: Hartz RE , Adams HT 
Published: March 2009

Atmospheric conditions, whether at room temperature or in high temperature ovens, do not consist of pure environments. Resorcinol-formaldehyde-latex (RFL) dipped nylon and polyester tire cords lose adhesion to rubber stocks upon exposure to environmental pollutants. Adhesion degradation is most severe upon exposure to ozone and ozone-ultraviolet light. Other degradants such as nitric oxide, nitrogen dioxide, sulfur dioxide, heat, and air have a much lesser effect on adhesion loss. Degradation is caused by attack of the olefinic double bonds of the butadiene component of the rubber latex to reduce sites for cure with stock formulations. Addition of proprietary waxes to the RFL dip provides protection from adhesion loss during exposure by blooming to the surface of the dip on the cord.
Brass coated steel rapidly loses adhesion upon exposure to nitrogen dioxide and sulfur dioxide. However, humidity and heat do not affect adhesion loss. Corrosion of the metals catalyzed by acidic pollutants eliminates sites for cure to the sulfur adducts of the adhesion stocks.
Effects of Specimen Geometry on the J1-R Curve for ASTM A533B Steel
Authors: Vassilaros MG , Joyce JA , Gudas JP 
Published: March 2009

Two experiments were performed with ASTM A533B steel to evaluate effects of compact specimen geometry on the JI versus crack growth resistance curve and evaluate validity limits for J-controlled crack growth. Side groove depth and crack length ratios were investigated with 1T compact tension specimens (1TCT) of HSST-02 plate. An investigation of thickness to ligament ratios over a broad range was conducted with 2T plan compact specimens using HSST-03 plate. All tests were performed at 150°C (302°F) using a computer-interactive unloading compliance test procedure.
Results showed that side grooves straightened the crack growth. With HSST-02 plate, total side groove depth of 20 percent is required to eliminate crack tunneling. With this steel, side grooves served to reduce JIc from nonside groove measurements and also resulted in less measurement variability. A change in slip mode from planar to cross-slip did not affect the tearing modulus measurement, which was shown to be insensitive to thickness to ligament ratios ranging from 0.63 to 3.89. The minimum ω required for J-controlled crack growth for this material was shown to be on the order of one when considering less than 6 percent crack extension.
Measurement of Crack Growth Resistance of A533B Wide Plate Tests
Authors: Garwood SJ 
Published: March 2009

Nine 500-mm-wide, 110-mm-thick A533B Class I wide plates were tested at +70°C (158°F). Three crack types were used: (1) semi-elliptical, (2) surface notched, and (3) through-thickness center cracked. Various notch depths were employed. The progress of the stable propagating ductile tear resulting in the specimen from the use of the relatively stiff wide-plate rig was marked periodically using an unloading technique.
Estimates of the crack propagation resistance JR-curves for these tests were made and compared to resistance curves obtained from small scale laboratory bend specimens.
The crack morphology exhibited by the surface notched wide-plate specimens, which propagate in the through-thickness direction, was essentially normal ductile rupture in contrast to the through-thickness crack, which showed mostly shear rupture.
Semi-elliptical notched specimens initially behaved in a similar fashion to the surface notched, and after penetration of the plate thickness, continuing propagation behaved as a center cracked plate.
Derivations of a simple estimation formula for the JR-curves for the surface notched and semi-elliptical geometries have been made. Using these formulas, comparisons of all tests with the crack propagating in the L-T and L-S orientations were made.
The results of large-scale tension and large- and small-scale bend tests indicate that laboratory tests give reasonable lower bound estimates of the more structurally relevant tension situation in the L-T orientation where full-plate-thickness bend specimens are employed.
In the L-S orientation much more restrictive thickness requirements are necessary to achieve conservative estimates from laboratory bend tests and as an initial guideline the requirement B &gt; 25(JR/σY) is suggested for surface notched geometries although this may not be restrictive enough for very ductile materials.
Statistical Characterization of Fracture in the Transition Region
Authors: Landes JD , Shaffer DH 
Published: March 2009

Fracture toughness results are measured in the transition region for an ASTM A471 Ni-Cr-Mo-V steel on two specimen sizes 1T compact tension (CT) and 4T-CT. The results are typical for steels in the transition in that the smaller specimen toughness values are greater than the larger specimen results. Two explanations are given for this behavior. One explanation, based on loss of constraint, suggests that small specimens cannot be used to characterize the toughness of a large structure in the transition region. A second explanation, based on a statistical model, suggests that small specimen results when properly analyzed can be used to characterize the toughness of large structures.
The results of these tests and others support the statistical model as the proper explanation for the observed difference in toughness between small and large specimens in the transition. The model gives a method for analyzing small specimen results to properly predict the toughness of a large structure.
Load Relaxation Testing and Material Constitutive Relations
Authors: Hart EW 
Published: March 2009

The phenomenon of load relaxation for a specimen in a tension test configuration is not in itself a material property. The resultant record of load P as a function of elapsed time t is dependent on the conditions of loading in the test as well as on the material elastic and inelastic properties. For this reason, the term “load” relaxation seems preferable to “stress” relaxation as a nomenclature for the test, and we shall employ this term in the paper.
In order to deduce the intrinsic material flow properties from the testing results it is desirable to convert the load-time record P(t) to a specimen record of stress versus strain rate σ(ϵ). In some cases the explicit time dependence is significant, and so each stress-strain rate point can also be associated with the current time t if desired. This data conversion can be always accomplished.
In the following we shall describe the method of data analysis that is desirable for determining the inelastic constitutive relations of a material. We shall discuss some refinements of the experimental technique that have proven very important in such analysis. We shall then illustrate the expected results for several types of ideal material behavior and finally show the type of results and conclusions for some real materials and test conditions.
Room-Temperature Stress Relaxation of High-Strength Strip and Wire Spring Steels—Procedures and Data
Authors: Idermark SUV , Johansson ER 
Published: March 2009

Stress relaxation of strip spring steels was investigated with the vibrating string technique. The modified AISI 301 austenitie stainless steel had the lowest relaxation rate up to 170 h followed by a standard AISI 301 stainless steel, a martensitic stainless chromium steel (Type 420), a texture rolled carbon steel (Type 1078), and a hardened and tempered carbon steel (Type 1074). A high elastic limit had a beneficial effect in lowering the stress relaxation rate. The stress relaxation rate for the carbon steels was accelerated after an initial period. The specimens that had an acceleration in stress relaxation also exhibited a simultaneous change in stress-strain behavior as proved by tension testing.
Helical extension wire springs were tested at constant length in a test rig. The modified AISI 301 austenitie stainless steel had the best relaxation properties, followed by a 17-7 precipitation hardenable steel and a standard AISI 302 austenitie stainless steel. An increase in prestress level decreased the stress relaxation as measured at the same testing stress. Springs coiled from wire with the highest values of yield and tensile strength gave the lowest relaxation rate.
A Review of the Constant Strain-Rate Stress Corrosion Cracking Test
Authors: Kim CD , Wilde BE 
Published: March 2009

A review of six years operational experience in using the slow strain test procedure has indicated several unique advantages associated with dynamic strain techniques and also identified an area of limitation.
The chief advantage of the dynamic slow strain test procedure is that it is much more aggressive in producing stress corrosion cracking (SCC) than conventional constant-strain or constant-load tests, so that the testing time is considerably reduced. The procedure reduces the incubation period for crack nucleation by virtue of continuous straining above the elastic limit on smooth surfaces, and avoids the pitfalls associated with reducing incubation times by means of precracking and other methods. With the latter methods, marked chemical inhomogeneities in an environment have been observed so that spurious results are obtained.
The slow strain test is also ideally suited, on a “go-no-go” basis, for rapid sorting or screening of environment/metal or environment/metallurgical-condition combinations which can produce SCC. However, the test is not suitable for ranking materials with regard to their resistance to SCC when the strength levels and microstructure vary widely. Furthermore, because of the test severity, discretion must be exercised in translating susceptibility to SCC observed in the laboratory to anticipated performance in service.