bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theory and Application of Evaluation Tests for Detecting Susceptibility to Intergranular Attack in Stainless Steels and Related Alloys— Problems and Opportunities
Authors: Streicher MA 
Published: March 2009

The first evaluation methods for stainless steels, the 65 percent nitric acid and the copper sulfate-sulfuric acid tests, were originally simulated service tests. Later, when the results obtained with these tests were used to prevent failures by intergranular attack in other media, they were transformed into methods of general applicability for detecting susceptibility to intergranular attack. Since the 1949 ASTM symposium on this subject, several new methods have been introduced to accomplish this goal more rapidly and effectively. This has led to a large variety of ASTM test methods which also include the nickel-rich, chromium-bearing alloys.
In an overview of all current ASTM test practices for detecting susceptibility to intergranular attack, opportunities for improvements and simplifications are discussed. New data are presented on the properties of the various copper sulfate-sulfuric acid tests and on the performance of the new iron-chromium-molybdenum ferritic stainless steels in evaluation test solutions. The need for assessment criteria for determining the occurrence of intergranular attack in all test practices is emphasized with proposals for such criteria. A plan for a greatly reduced number of improved tests is proposed. The introduction of new melting, refining, and casting methods and of new iron-chromium-molybdenum stainless steels has increased the importance of evaluation test methods and the need for improvements in ASTM test practices.
Effect of Salt Water and High-Temperature Exposure on Boron-Aluminum Composites
Authors: Dardi LE , Kreider KG 
Published: March 2009

Boron-aluminum composites are being considered for aerospace applications, including jet engine fan blades and structural airframe components. The high specific modulus and strength of this material make it attractive in the design of these components while incorporating weight savings and increased structural efficiency. But two significant hostile environments are present that can jeopardize its outstanding properties; namely, enhanced corrosion in saltwater environments and high-temperature (air) exposures that are present in supersonic aircraft applications. This work was planned to identify critical properties that relate these environments to possible aerospace applications. In particular, the application of boron aluminum in jet engine fan blades was instrumental in the choice of experiment methods and analysis. Some of the findings in this investigation are summarized in the following.
Exposure of 2024 and 6061 matrix BORSIC + aluminum composites to synthetic sea salt spray at 95°F and 100 ksi bending stress results in matrix corrosion that is most severe with 2024 matrix material in the as-fabricated condition. Both 6061-F and 6061-T6 matrix composites exhibit general corrosion without preference for regions of high stress, whereas 2024-F and 2024-T6 matrix composites display depths of attack that are approximately twice as great on the tensile surfaces as the compressive surfaces. The flexural strengths of 6061-F and 6061-T6 matrix composites are unaffected by exposure for periods up to one month. The strength of BORSIC + 2024-F and BORSIC + 2024-T6 matrix composites can be reduced by as much as 100 percent and 14 percent, respectively, after one month as a result of matrix attack. The longitudinal strength of BORSIC filament is not degraded as a result of exposure to the humid salt environment.
The longitudinal strength of 61 v/o 5.7-mil BORSIC + 6061-F was degraded approximately 10 percent after 1000 h at 700°F. Transverse properties were unaffected. Uncoated 4.0-mil boron + 6061-F material exhibited a 12 percent decrease in longitudinal strength (175 × 103 psi to 154 × 103 psi) with the same exposure conditions. The transverse strength of this material was unaffected.
Although degradation of mechanical properties was achieved under these severe conditions, it is apparent that only the 2024 matrix alloy in saltwater exposure was found to be unsuitable for turbine engine fan blades.
Evaluation of Graphite Fiber Reinforced Plastic Composites for Use in Unlubricated Sliding Bearings
Authors: Brown RD , Blackstone WR 
Published: March 2009

Conforming shoe-type specimens of radial fiber graphite/epoxy, tangential fiber graphite/epoxy, and radial fiber graphite/polyimide were fabricated and evaluated as bearing materials. Their performance was compared against that of specimens cut from commercially available Teflon-lined (TFE-lined) bearings of MS 21240 type. All the test specimens were run against hardened steel sleeves. Test conditions included bearing loads ranging from 9 to 30 ksi (6.2 × 107 to 20.7 × 107 N/m2); oscillatory motion of ±25 deg at 30 or 60 cpm (0.5 or 1.0 Hz); equilibrium sleeve temperatures at the start of test ranging from 80 to 400°F (300 to 477 K); and test durations of 2 h except where earlier specimen failure occurred. Compressive strength and thermal conductivity measurements were also made on the graphite/epoxy materials.
At temperatures of 350°F (450 K) and lower, the TFE material exhibited the best friction and wear characteristics of the four materials tested. The graphite/polyimide material exhibited friction and wear performance superior to that of either of the graphite/epoxy materials over the range of conditions used. At combinations of high load and temperatures in excess of 350°F (450 K), the wear rate of graphite/polyimide material was comparable to that of the TFE material, although friction was higher.
Evaluation of the Toughness of Thick Medium-Strength Steels by Using Linear-Elastic Fracture Mechanics and Correlations Between KIc and Charpy V-Notch
Authors: Marandet B , Sanz G 
Published: March 2009

Fracture toughness of medium strength steels (A533B, 2.25Cr-1Mo, electroslag welds, cast steels …) with different heat treatments was investigated by using big compact specimens.
The comparison of Charpy V and KIc transition curves shows that a very good correlation exists between the transition temperatures defined by these two tests. By defining TKIc as the temperature at which KIc = 100 Mpa√m and TK 28 as the temperature at which Charpy V-notch (CVN) = 28 J, the relationship is
TKIc = 9 + 1.37 TK 28 (°C)
The fact that the slope of this straight line is not one makes the existence of a direct correlation between KIc and CVN impossible. Nevertheless, this relationship may be used to predict accurately KIc from CVN. If one shifts the KIc versus temperature curves in order for TKIc and TK 28 to coincide, KIc and CVN are related by
KIc = 19 (KV)½(MPa√m, J)
Predicting KIc versus temperature curve from the Charpy V transition curve can thus be achieved in several steps.
Determination of Stress Intensities of Through-Cracks in a Plate Structure Under Uncertain Boundary Conditions by Means of Strain Gages
Authors: Kitagawa H , Ishikawa H 
Published: March 2009

It is often required to determine the values of the stress-intensity factors at a tip of a given two-dimensional through-crack even when some of the boundary conditions are not exactly given.
A new method is proposed for determination of this kind of stress-intensity factor by combining experimental stress-analysis techniques, fracture mechanics, and variational methods.
In this paper, the stresses on the boundary of a small domain surrounding a crack tip were measured by electric resistance strain gages, and the stress-intensity factors were calculated by variational method. Sufficient accuracy was obtained. For convenience of applications, a method by means of a calculating table was proposed.
Experimental Verification of the JIc and Equivalent Energy Methods for the Evaluation of the Fracture Toughness of Steels
Authors: Marandet B , Sanz G 
Published: March 2009

The critical value JIc and the apparent fracture toughness KBd are measured with a single small specimen (compact tension or three-point-bend bar) loaded in the elastic-plastic range. Initiation is detected during loading by an electrical potential method.
For the steels studied here (2.25Cr-1Mo, electroslag weld, manganese cast steel), the KIc values deduced from JIc are in agreement with the KIc values directly measured with thick specimens in the transition-temperature range. Furthermore, the equivalent energy procedure gives the same results as those obtained by the J-integral method.
Oxidation of Zirconium During a High-Temperature Transient
Authors: Sawatzky A , Ledoux GA , Jones S 
Published: March 2009

A physical model describing oxidation and oxygen diffusion under non-isothermal conditions is presented. It assumes (a) equilibrium at phase interfaces, as is usual in the treatment of diffusion, and (b) oxygen supersaturation of the β-zirconium to precipitate α-zirconium on cooling. An important consideration, not required in isothermal diffusion, is that the equilibrium oxygen concentrations in the α- and β-phases decrease with temperature.
During isothermal oxidation at temperatures above 850°C, the phase distribution is zirconium dioxide (ZrO2/α/β. This model predicts that on slow cooling, oxygen in the β-region diffuses to the α/β interface leading to a depletion of oxygen in this region with a corresponding increase in the thickness of the α-layer. With more rapid cooling, α-zirconium is precipitated in the β-region near the α/β interface. The oxygen concentration of the β-region is determined not by the maximum temperature in the transient but by the lowest temperature at which appreciable diffusion is still possible.
Zircaloy Cladding Behavior During Irradiation Tests Under Power-Cooling-Mismatch Conditions
Authors: Hobbins RR , Smolik GR , Gibson GW 
Published: March 2009

The behavior of Zircaloy-clad fuel rods for light water reactors under off-normal operating conditions is being studied in the Power Burst Facility. Fuel rods from three irradiation experiments conducted under power-cooling-mismatch conditions have been examined destructively in remote handling facilities. The postirradiation examinations of these pressurized water reactor-type rods have included visual and photographic examination, physical dimensioning, and metallography.
The examinations have revealed the collapse of the Zircaloy cladding onto the fuel pellets and into the gaps between pellets (waisting) of these fuel rods. In some cases, severe oxidation on the external surface of the cladding from Zircaloy-steam reaction and on the internal surface from Zircaloy-uranium dioxide (Zr-UO2) reaction caused embrittlement of the cladding which resulted in cladding cracking and fuel rod fracture.
Cladding temperatures were estimated from the microstructures using a correlation between temperature, time, and the combined thickness of the zirconium dioxide (ZrO2) and oxygen-stabilized alpha layers. Using this method, cladding temperatures up to 1640 K have been estimated on the fuel rods tested.
Cladding collapse occurred at temperatures estimated to be in the range of 1020 to 1170 K. The reactor coolant system pressure was 14.5 to 15.2 MPa and the rods were prepressurized to pressures within the range 2.6 to 3.8 MPa.
Corrosion Monitoring of Steam Generating Heavy Water Reactor Pressure Tubes
Authors: Sheppard MF , Tyzack C 
Published: March 2009

The corrosion of zirconium alloys under boiling water reactor (BWR) conditions is enhanced by irradiation; therefore, it was necessary to verify the expected behavior in steam generating heavy water reactor (SGHWR) of pressure tabes manufactured by different routes. Specimens of each material and others of interest were exposed to the coolant inside perforated fuel cans replacing fuel pins in otherwise standard SGHWR fuel clusters. After irradiation, specimens were decrudded chemically and weight gains were measured. Hydrogen pick-up was found by hot vacuum degassing. Specimens were also examined metallographically.
Weight gains from irradiations up to 531 effective full-power days (EFPD) generally show a reasonably linear correlation with the fast fluence to which they have been exposed. There is a variation in corrosion rate between Zircaloy-2 materials of different histories; a quench treatment at the billet stage seems to be beneficial. Metallographic examination of specimens and fuel cladding showed the presence of nodular corrosion after exposure ia reactor in oxygenated water. The extent of nodular formation varied with material and generally followed the weight gain patterns. The paper includes a discussion on mechanistic aspects of nodular corrosion.
Hydrogen up-take by the specimens appears to be largely independent of corrosion weight gain making percentage pick-up figures of dubious value. The amounts of hydrogen taken-up, however, are small, representing less than 5 percent for many materials. Extrapolation of results to the expected full reactor life indicates that neither loss of section by corrosion nor hydrogen pick-up by the pressure tube should be life limiting.
Effects of Time on Damping Ratio of Clays
Authors: Marcuson WF , Wahls HE 
Published: March 2009

Laboratory tests with a Hardin oscillator were used to study the time-dependent characteristics of the damping ratio of isotropically consolidated specimens of kaolinite and calcium bentonite. Damping was determined using a steady-state method and from the decay of free vibrations. After completion of primary consolidation, the dynamic response was studied as a function of time for both drained and undrained conditions.
The damping ratio decreased approximately 12 percent for kaolinite and 25 percent for bentonite per logarithmic cycle of a dimensionless time ratio during secondary compression. To evaluate the effects of time in clay soils, at least one test should be continued to five to ten times the time at the end of primary consolidation.
Errors due to diffusion of air into the specimen were eliminated by using a mercury jacket around the specimen. The apparatus damping constant was found to vary significantly from test to test because of minor variations in the apparatus setup, and hence the apparatus must be recalibrated for each test.
Dynamic Properties of Mass Concrete
Authors: Saucier KL , Carpenter L 
Published: March 2009

The objective of this study was to determine the tensile strength, cyclical behavior, and stress-strain relationships for concrete under loading conditions ( 1 to 10 Hz) such as could be produced by an earthquake.
Dynamic direct tension tests and stress-reversal tests were conducted on core specimens from two concrete mixtures representative of mass concrete. Test procedures were developed for cyclical loading and loading to failure in 0.25 to 0.025 s, which represent one fourth of a cycle having a frequency of 1 to 10 Hz. Stress-strain measurements were made on selected specimens. The procedures used could be modified to become ASTM test methods for direct-tension and stress-reversal tests of rock.
The tests indicated that there was no significant difference in tensile strength determined statically or dynamically on dry specimens. A 30 percent increase in strength was indicated for wet specimens tested dynamically. Very little hysteresis was evident in the tensile stress-strain curves. The results should be useful in studies conducted to determine the earthquake resistance of mass-concrete structures.
Toxicity Testing in the United Kingdom for the Evaluation of Oil Slick Dispersants
Authors: Norton MG , Franklin FL , Blackman RAA 
Published: March 2009

Until recently, the toxicity of dispersants approved for use in U.K. waters was evaluated by a static bioassay on the dispersant alone.
Following the 1974 Dumping at Sea Act, dispersant evaluation methods were reviewed and dispersants are now licensed for sea (offshore) or for beach use, based on two tests to assess the environmental effect of the dispersant use.
The “sea” test assesses the toxicity to Crangon crangon of a chemically dispersed oil and compares it with the toxicity of the oil alone. Mortality is measured over a period of 100 min at an oil concentration of 1000 ppm.
The “beach” test assesses the toxicity of the dispersant alone to a typical intertidal organism, Patella vulgata, by spraying with dispersant and rinsing in a simulated tidal cycle. Mortalities are measured after 72 h and compared with those of an oil control.
The rationale behind the development of these tests is described, together with the experimental results. The U.K. criteria for licensing products on the basis of these test results are also discussed.
Some Guidelines for Oil-Spill Control in Coastal Environments, Based on Field Studies of Four Oil Spills
Authors: Gundlach ER , Hayes MO , Ruby CH , Ward LG , Blount AE , Fischer IA , Stein RJ 
Published: March 2009

It is essential to understand the factors influencing the distribution, damage and long-term persistence of oil spills in order to adequately plan for, and apply appropriate cleanup techniques. Based on the study of two massive spills [Metula, 47 700 t (53 000 tons)]; [Urquiola, 22 500 to 27 000 t (25 000 to 30 000 tons)] and two smaller spills under ice conditions [Bouchard 65, 248 t (276 tons); Ethel H., 1350 t (1500 tons)], these factors are (1) wind stress and water currents, (2) beach activity and grain size, (3) tidal stage, (4) wave energy, (5) oil quantity and composition, and (6) ice effects, where applicable.
Coastal environments vary significantly in terms of resultant damage from spilled oil. Subsequent cleanup by dispersants or mechanical means should be planned accordingly. Considering the aforementioned factors, as well as initial biological effects, a classification of coastal environments in terms of potential oil spill damage has been developed. In order of increasing vulnerability, these environments are: (1) exposed, steeply dipping or cliffed rocky shores; (2) eroding wave-cut platforms; (3) fine-sand beaches; (4) coarse-sand beaches; (5) exposed, compacted tidal flats; (6) mixed sand and gravel beaches; (7) gravel beaches; (8) sheltered rocky coasts; (9) sheltered tidal flats; and (10) salt marshes and mangroves. This classification can be used to delineate oil-sensitive environments as part of an overall contingency plan to limit damage during an oil spill.
Apparatus for Application of Chemical Dispersants on Open Sea
Authors: Allen TE 
Published: March 2009

A chemical dispersant spraying system for use on seagoing workboats has been developed. Using two spray booms, the system can spray a path up to 18.3 m (60 ft) wide at a speed of 8 knots, thus covering approximately 0.27 km2/h (67 acres per hour). The design is based on the use of “self-mix surfactant,” which requires little mixing energy for effective dispersion of the oil slick. Three of these systems have been completed for Clean Atlantic Associates, an oil spill cleanup cooperative.
The system is made up of an apparatus for deploying and supporting two 9.1-m (30 ft) spray booms, a 33.6-kW (45 hp) pump skid for pumping a mixture of seawater and dispersant, and Marine Portable 1892.5 litre (500 gal) tankage for storing the dispersant.
The spray apparatus is designed to be attached to the bow of the boat. This allows the boom to spray the mixture of seawater and dispersant ahead of the bow wake. Subsequent mixing energy is provided by the bow wake. When not using a self-mix dispersant, additional mixing energy can be provided by breaker boards; however, these are not included in this system.
Seawater is drawn from an overboard suction line, proportioned with the chemical dispersant at a typical ratio of 33 to 1, and pumped at high pressure, 0.62 to 0.69 N/m2 (90 to 100 psi), through fan-type nozzles.
The entire system is readily adaptable to various sizes and shapes of vessels, and operates independently of the vessel to which it is mounted.
Thermal Conductivity Measurements on High-Temperature Fibrous Insulations by the Hot-Wire Method
Authors: Jackson AJ , Adams J , Millar RC 
Published: March 2009

We have developed equipment to determine the “thermal conductivity” of insulating materials, in the temperature range 25° to 1600°C, by the hot-wire method. We have based our method on the German draft standard DIN 51046 and on the work of Padgett and Davis at the British Ceramic Research Association (BCRA). The method has been applied to measurements on polycrystalline alumina fibers, where the “thermal conductivities” range from 0.03 to 0.8 W/m-K. This paper gives details of our experiences with the hot-wire method and indicates some areas where we have found difficulties that are not completely covered in the specification.
In order to assess the value of “thermal conductivity” data obtained by the hot-wire method, we have, where possible, tried to compare our results with those obtained by parallel-plate methods. The dangers of making such a comparison are indicated, but the agreement between the results obtained by the two different methods gives us confidence in their reliability for insulation design.
Laboratory and Field Investigations of Moisture Absorption and Its Effect on Thermal Performance of Various Insulations
Authors: Dechow FJ , Epstein KA 
Published: March 2009

Much work has been done in Europe, Canada, and the United States with respect to the effect of moisture on the thermal efficiency of various insulations. However, very little research has been done to orient the laboratory test methods to the actual field conditions in which the various insulations will be used.
This paper reports on the moisture performance characteristics of various thermal insulations under laboratory conditions and under actual field conditions. The various moisture effects, such as freeze-thaw cycling in the presence of water, water absorption, and water vapor transmission, which occur in insulations in upside-down roof systems and below-grade applications, reduced the thermal efficiency of all insulations tested. This loss of thermal resistance of the common insulating materials using both laboratory methods and field data is related to the volume of water present in the insulations. The minimum performance criteria for insulations exposed to the various laboratory test methods and to actual field conditions are also discussed. The insulations investigated include fiber glass, fiberboard, expanded (bead) polystyrene, extruded polystyrene, polyurethanes, and cellular glass. The effect of various top coverings for upside-down roof applications on the thermal resistance performance of insulations is also discussed.