bluuebunny/crossref_metadata_2025 huggingface dataset:
Megascopic Description of Coal with Particular Reference to Seams in Southern Illinois
Authors: Cameron AR
Published: March 2009

Polished column samples representing the Davis, Dekoven, No. 5, and No. 6 seams of southern Illinois were studied megascopically. The lithotypes identified were vitrain, clarain (bright and dull), durain, and fusain. Partings also were determined. Layers on the polished surfaces were identified down to a thickness of 1 mm. On the basis of these data, the seams were divided into petrographically distinctive intervals which were characterized as bright, semibright, semidull, and dull, depending upon the proportions of vitrain and bright clarain present. A comparison of profiles suggested that each seam has its own characteristic pattern and that this pattern has lateral persistence as indicated by the No. 6 seam profiles. A comparison of polished column data with in-situ descriptions for the No. 6 seam was less satisfactory, revealing only general similarities. Maceral contents determined on a number of the megascopically identified layers from two of the columns studied showed wide ranges for some of the lithotypes, particularly bright and dull clarain and durain, even though mean maceral contents increased and decreased according to predictable patterns. Mineral matter appeared to be a major factor in decreasing the luster of some layers resulting in their assignment to durain and dull clarain.
Life Expectancy of Recycled Asphalt Paving
Authors: Taylor NH
Published: March 2009

In 1929, three types of failure occurred in large areas of asphalt surfacing in Singapore. Research undertaken in 1930 to 1931 at the University of London, appeared to indicate the causes. The problem was not only that of preparing revised specifications but that of finding economical means of maintaining the failed surfacings. Recycling was found to be possible in each case, and the recycled material had a life of from 25 to 30 years. In 1947, a contracting company was formed in Bombay, India, for recycling defective asphalt surfacings in that city, and contracts for such work have continued to be placed with the company. Many of the surfaces treated in the first contract are still serviceable while some have been recycled for the second time. Only minor modifications of mixing plant are used and no proprietary additives were found to be necessary. Success depends entirely on effective laboratory control, and the life expectancy of a recycled asphalt surfacing need be no less than that of a surfacing prepared from entirely new materials.
Mixture Properties of Recycled Central Plant Materials
Authors: Epps JA , Little DN , O'Neal RJ , Gallaway BM
Published: March 2009

The objectives of the research reported are to (a) define the material properties of central plant recycled mixes in Texas, (b) compare properties of these recycled mixes with conventional paving mixtures normally used in Texas, (c) evaluate the performance of the pavements containing central plant recycled mixes, and (d) compare performance of pavements constructed with recycled and conventional paving mixtures.

Hveem, Marshall, resilient modulus, indirect tensile, direct tensile, and water sensitivity properties are reported for the recycled mixtures compacted both in the laboratory and under normal field procedures. Bituminous mixtures investigated include recycled asphalt concrete and recycled portland cement concrete.

Performance is reported in terms of serviceability index as measured by a ride meter and by the use of a visual condition survey.

The results of this study indicate that suitable bituminous mixtures can be produced by central plant recycling operations. Performance of pavements containing recycled mixtures appears to be suitable.
Engineering and Manufacturing Development of a New Metric Fastener — 12-Spline Flange Bolt
Authors: Kasuba R , Shugart J
Published: March 2009

This paper discusses the engineering and manufacturing development of metric 12-spline flange bolts from “blue sky” ideas through final stages of analysis, testing, and manufacturing.

This fastener was developed in the course of a program to study the development of an Optimum Metric Fastener System (OMFS). Finite element techniques, photoelastic tests, and extensive structural as well as wrenching tests were used to establish a final configuration commensurate with preselected engineering and economic criteria. The developed and manufactured 12-spline flange bolt performance characteristics can be described by lower bearing pressures, lower head stress concentration factors, and lower head spring rates than those found in existing hexagon head designs. Additionally, substantial raw material savings are predicted. Metric 12-spline flange bolts are documented in OMFS-9 (also under consideration as ANSI B18.2.5).
A Rapid and Sensitive Quantitative Method for Determining Oil in Water
Authors: Griffith K , Thomas D , Ferrin C , Deem C
Published: March 2009

This paper concerns the quantitative determination of oil in water by turbidity measurement. The method is sensitive to 0.5 ppm (volume) or less and is rapid and reasonably accurate. The method is not intended to replace the various extractive methods for determining absolute values of oil content. It is most useful when many samples must be run to determine when corrective adjustments are required. The equipment is not delicate and is portable, which makes it ideal for field testing. Turbidity is affected by the kind of oil, contaminants, shear rate, shear time, and temperature. These parameters are discussed, and their effects are shown with experimental data.
Applicability of a Measurement System: Sensor Response and Representativeness
Authors: MacCready PB
Published: March 2009

A complete view of the management (acquiring and use) of meteorological data requires the consideration of many factors, from the dynamic response characteristics of the sensor to the time and spatial representiveness of the final numerical quantity produced. The mathematical techniques for quantifying the various factors associated with a particular measurement are well developed. This paper reviews some fundamentals of the response and errors of typical meteorological sensors, with an emphasis on the sort of responses and errors that arise when the instrument is used in the real turbulent atmosphere, and also reviews factors of averaging and representativeness. Broader aspects of representativeness are also discussed from the perspective of incorporating the measurements into complete atmospheric descriptions or models.
Remote Sensing of the Atmosphere from Environmental Satellites
Authors: Allison LJ , Wexler R , Laughlin CR , Bandeen WR
Published: March 2009

The use of satellites for the remote sensing of the earth and its atmosphere is reviewed. Meteorological satellites have been in use since 1960. The polar orbiting satellites at 650 to 1500 km make 12 to 14 orbits daily with nearly full earth coverage. The geosynchronous satellites at 36 000 km remain approximately fixed in space relative to the earth and view the same area continuously.

Cameras obtaining earth images in the visible detect clouds and monitor storm systems. Infrared radiometers measure temperatures of the surface or cloud tops and also determine amounts of ozone and water vapor in the atmosphere. Radiometers sensitive to different spectral regions in absorption bands (such as carbon dioxide [CO2] at 15 and 4.3 μm) are used to determine atmospheric vertical temperature profiles.

The earth's radiation budget is determined from satellite measurements of the reflected solar radiation and the emitted longwave terrestrial radiation.

Atmospheric winds are obtained by cloud tracking from geosynchronous satellites. A major problem is height determination. Infrared “window” measurements of the brightness temperature from clouds provide some information on cloud top heights, but cloud emisisivity and sensor resolution are still sources of error.

Microwave imagery has been used to determine rainfall intensities over the ocean, snow, and ice cover and flood mapping through clouds. It has also been possible to distinguish between first and multiyear ice. There is a potential capability for measuring soil moisture using long-wavelength (21 cm) radiometers. Landsat visual and near-infrared measurements also allow flood monitoring and observations of crop growth.

The Nimbus 4 Backscatter Ultraviolet (BUV) instrument has provided seven years of measurements from which total ozone and vertical ozone distribution can be determined.

Future missions include TIROS N satellites with improved capabilities for measuring sea surface temperatures, mapping snow and ice fields, monitoring global ozone, and continued measurements of the earth's radiation budget. SEASAT A will be devoted to oceanographic measurements.

Nimbus G sensors will observe certain atmospheric pollutants, oceanic parameters, and weather and climate variables. The Shuttle, in addition to serving as a launch vehicle for free flying satellites, will make periodic calibration checks of instruments on the free flyers and provide facilities for developing, testing, and demonstrating new remote sensors.
Effects on Atmospheric Diffusion of Meteorological Processes in Coastal Zones
Authors: Raynor GS
Published: March 2009

Meteorological processes in coastal zones differ from those inland because of the surface discontinuity between land and water. The differences in temperature between the two surfaces give rise to sea or lake breeze circulations, which can transport pollutants in nongradient directions and recirculate them over source areas. The step change in surface characteristics at the land-water interface also causes the formation of internal boundary layers that have different transport velocities and diffusion rates than those of the unmodified air upwind or above the boundary. These features require a more extensive measurement program and more versatile diffusion models than are needed for inland sites.
Distribution of Atmospheric Ozone and How It Is Measured
Authors: London J
Published: March 2009

The total amount of ozone in a vertical column has been measured spectroscopically at near ultraviolet and visible wavelengths, using ground- and satellite-based instruments. The vertical distribution of ozone from the surface up to approximately 100 km has been measured by a variety of techniques—chemical and optical— and from a number of observing platforms, including balloon, rocket, and satellite platforms. The various methods presently used for determining the atmospheric ozone distribution are reviewed, along with a discussion of their advantages and disadvantages.

The observed average distribution of total ozone for the period 1958-1975 shows the expected geographic and seasonal variations. The variations of total ozone, including hemispheric differences, are clearly associated with large-scale circulation processes in the lower stratosphere. Approximately ten years of observations of the vertical ozone distribution, up through the ozone maximum, also show geographic and seasonal variations strongly related to the lower stratosphere circulation. The distribution above the maximum, however, results from the interaction of photochemistry and stratospheric motions.
Description and Review of Global Measurements of Atmospheric Species from the Global Atmospheric Sampling Program (GASP)
Authors: Gauntner DJ , Holdeman JD , Briehl D , Humenik FM
Published: March 2009

A large volume of atmospheric constituent data is being collected in the global air lanes by specially equipped B-747 aircraft. This NASA program also obtains data from the similarly equipped NASA CV-990 aircraft during dedicated flights as in a recent near pole-to-pole latitude survey mission. Aerosol composition data are also collected with a NASA F-106 aircraft. Present measurements include ozone, carbon monoxide, water vapor, aerosol and condensation nuclei number densities, sulfates, and nitrates. Meteorological and flight parameters are also recorded for use in data analysis. The present aircraft operations obtain data between 6 and 13.5 km from 65 deg N between Europe and the North Pacific, and from 23 deg S over South America and 42 deg S over New Zealand. Typical constituent data from the aircraft operations during the first one and a half years are presented. Instrumentation is discussed.
Impact of Stratospheric Ozone on Tropospheric Concentrations
Authors: Reiter ER
Published: March 2009

Estimates of the natural background levels of stratospheric ozone (O3) in the lower troposphere are made using both stratospheric mass-balance calculations and radioactive fallout data. There is excellent agreement between both approaches, suggesting that there is a natural background of O3 of approximately 20 percent of the federal 1-h max value (the concentration not to be exceeded for longer than 1 h) or roughly 30 μ/g. The maximum stratospheric O3 concentrations in the lower troposphere on occasion can approach, and even exceed, this federal guideline value.
Note on Ozone, Carbon Monoxide, and Particulate Matter Concentrations
Authors: Catala J , Tejera MD , Zurita ME
Published: March 2009

A study of ozone variations near the ground at Madrid between February and December 1976, and the relation between ozone, carbon monoxide, and particulate matter concentrations during the same period are presented.
Calculation Methods for Predicting Smoke Movement in Building Fires and Designing Smoke Control Systems
Authors: Wakamatsu T
Published: March 2009

This paper proposes a basic direction for building systems designs based on scientific methods of quantitative evaluation in order to ensure human safety in building fires. Herein are described the position of the smoke control system as a subsystem of the whole system and the methods of designing the subsystem. Design of the subsystem is intended to produce a rational smoke control system best suited to each individual building based on computer simulation predictions of smoke flow or pressure distribution in the building. An outline of calculations on flowrate and pressure, concentration of smoke and gases, and thermal conditions is given. Calculations are divided into three steps according to the required level of accuracy, and these steps may be used appropriately, depending on specific goals. As an example of their application, the author demonstrates the design of a simplified smoke control system method, showing that it can provide simple, quantitative evaluation of the effectiveness of various smoke control systems under different conditions.
A Place for Voluntary Standards
Authors: Stevens RE
Published: March 2009

Voluntary standards are defined as standards used voluntarily. Of the more than 23 000 voluntary engineering standards in use today, most are commercial standards. The preparation of these standards represents the contributions of thousands of experts who write “consensus” standards that in some way affect every product, service, process, or environment. The future of voluntary standards will be assured if those standards are adequate and their use satisfactory.
International Standardization: Advantages, Progress, and Problems
Authors: Witteveen J , Twilt L
Published: March 2009

Four basic requirements of fire safety standards are proposed: the system of international rules must be objective, practical, mandatory, and consistent. Taking into account the state of the art, the fulfillment of these basic conditions is subjected to some substantial constraints. A very important constraint appears to emerge from the inconsistency between the quantification of levels of protection and the quantification of measures to meet the required levels. Other constraints follow from political and legal considerations. A discussion on these constraints is presented, and recommendations are given to face the identified problems.
Some General Remarks on Corona Discharges
Authors: Perkins JR
Published: March 2009

Saint Elmo's Fire was probably the first recorded form of corona. During stormy weather at sea, there appeared occasionally flamelike reddish or bluish lights on the tops of masts and on the ends of yardarms [1]. Sailors associated it with a benign protection and called it after their patron saint, Saint Elmo. Many years later Benjamin Franklin would claim, but not explain, that the sailors were right and that the wet masts and spars were acting as lightning rods, and were protecting. Because the rounded head of the mast wore this light like a crown or halo, it was later referred to as corona (the Latin word for crown) by the Latin-oriented scholars of those days. Many years later, as sources of high-voltage electricity were developed, the same light-like phenomena were observed in the laboratory and were traditionally referred to also as corona. Its usage persisted throughout the years, and the term corona is commonly used now to describe electrical discharge phenomena occurring either internally or externally, in or on electrical apparatus or devices.
Measurement of Partial Discharges in Inductive Apparatus: Transformers and Rotating Machines
Authors: Dakin TW
Published: March 2009

Much of the high-voltage inductive electrical apparatus such as transformers, reactors, motors, and generators cannot be considered as a simple lumped capacitance as is frequently done in the analysis of partial discharge circuit measurements. Particularly when the discharge occurs at a location remote from the accessible terminals for measurement of the equipment, a significant, often high, inductance occurs between the discharge site and the measurement terminals. Also, there is a distributed capacitance in parallel with this inductance, and a distributed shunt capacitance to ground. This is illustrated in Fig. 6.1. In practical apparatus, this inductive capacitance network is not usually as uniform from one end to the other, as Fig. 6.1 might indicate schematically, in an oversimplified way. This figure indicates only a sectionalized winding, and much of the apparatus is usually more complex than this. For example, no mutual inductance coupling is included in Fig. 6.1; also, no interleaving of high- and low-voltage windings or potential taps are indicated. These may introduce additional capacitance to ground at certain locations along the high-voltage winding. The inductive capacitance network of most windings, if analyzed in detail, is indeed very complex.
Corona Endurance Tests
Authors: McMahon EJ
Published: March 2009

Shortly after the end of World War II, scientists and engineers started to report on the mechanism of dielectric breakdown of solid organic insulating materials. During the first ten years, considerable effort was directed toward the effects of corona (partial discharges) on the surface of candidate materials with little attention paid to internal degradation leading to breakdown.
Acoustical Techniques for Detecting and Locating Electrical Discharges
Authors: Harrold RT
Published: March 2009

Acoustical detection of electrical discharges was perhaps the earliest technology used by man as he became aware of lightning flashes and the associated sound of thunder during rainstorms. Presumably, for millions of years man knew that the sound of thunder gave an early warning of an approaching storm (Lucretius (95-55 BC) was aware that lightning is seen before thunder is heard [1]). But not until more recent history, when man could record time accurately and measure the velocity of sound waves in air (Marsenne (1588–1648) measured the speed of sound in air using a pendulum and reported a value of 316.46 m/s [2].), could he estimate the distance to the lightning discharge that caused the sound waves (DeLisle [3] in 1738). With the dawn of the electrical age (circa 1874 [4]), it was apparent that high-voltage sparks in air produced acoustic emissions in a similar fashion, but on a much reduced scale, to lightning. As increasingly higher voltages were used, electrical coronas at highly stressed regions on electrical apparatus, such as the uninsulated conductors of high-voltage power lines, could be seen by eye in the dark, and their associated acoustic emissions heard by ear.
Irradiation and Thermal Effects on the Tensile Properties of Inconel-718
Authors: Ward AL , Steichen JM , Knecht RL
Published: March 2009

The effects of neutron irradiation and out-of-flux aging on the tensile properties of wrought and weld-deposited Inconel-718 have been investigated following fast-reactor irradiation to total fluences ranging from 0.55 × 1022 neutrons (n)/cm2 (∼400°C) (752°F) to 6.6 × 1022 n/cm2 (649°C) (1200°F) and thermal exposure at 538 and 649°C (1000 and 1200°F) for durations to 10 000 h. Classical irradiation hardening is exhibited by this very strong material following irradiation at low temperature (∼400°C) (752°F) to relatively low fluence (∼1022 n/cm2) and also at high temperature when very high fluence (6.6 × 1022 n/cm2) is accumulated. At test temperatures ≥538°C (1000°F), ductility losses arising from helium embrittlement are evident for all irradiation conditions and at high fluences are so severe as to restrict the strength to lower than expected values.

Low postirradiation strength, compared to that following out-of-flux aging for equivalent durations, suggests that irradiation accelerates the thermal overaging process at 538°C (1000°F). At 649°C (1200°F), the results are obscured by embrittlement and coincident limitations on strain hardenability.
Development and Evaluation of a Stress-Free Swelling Correlation for 20 Percent Cold-Worked Type 316 Stainless Steel
Authors: Garner FA , Laidler JJ , Guthrie GL
Published: March 2009

Sufficient data have been accumulated on the swelling behavior of 20 percent cold-worked Type 316 stainless steel to make predictions of the anticipated swelling in the fast test reactor (FTR). A predictive stress-free swelling correlation has been developed employing a limited data base developed in the Experimental Breeder Reactor-II (EBR-II). Insight gained from electron and ion simulation experiments aided in the correlation development. Application of this correlation to environments other than fast reactor core regions requires consideration of the differences in neutron spectrum and displacement rate in such environments.
Dependence of Void Swelling on the Electron Vacancy Concentration
Authors: Watkin JS
Published: March 2009

Large variations have been noted between the swelling of different iron, chromium, nickel alloys and suggestions have been made that the differences are due to variations in the carbon, silicon, phosphorus, and nickel content of the alloys. Harries has postulated that variations in the solute concentration of the gamma matrix could be responsible for the different swelling behavior and that the formation of any second phase which leads to a depletion in the solute concentration will in turn lead to an impairment in swelling resistance. The swelling of several commercial alloys irradiated at 600°C (1112°F) in the Dounreay Fast Reactor lend general support to Harries' suggestion and the swelling at 30 atomic displacements per atom (dpa) has been shown to increase with the calculated equilibrium fraction of sigma phase. A superior correlation has been shown to exist between the swelling and calculated electron vacancy concentration of the matrix and a critical value of 2.58 electron vacancies per atom has been observed above which swelling increases rapidly and below which swelling is small.
Evaluation of the Maine Yankee Reactor Beltline Materials
Authors: Wullaert RA , Sheckherd JW , Smith RW
Published: March 2009

Tension and Charpy V-notch specimens of the base metal, heat-affected zone metal, and weld metal from the beltline region of the Maine Yankee pressure vessel (Type A533B-1 steel) were irradiated in an accelerated surveillance capsule. The specimens were exposed to a fluence of 1.3 × 1019 neutrons (n)/cm2 (>1 MeV) at 550 °F (288 °C). Charpy V-notch specimens of a standard reference material (SRM) were also irradiated in the surveillance capsule as a correlation monitor for dosimetry. Irradiation increased the yield and ultimate strength and decreased the ductility of all of the Maine Yankee materials. The yield strength increased 50 percent for the weld metal and 35 percent for the base and heat-affected zone materials. Radiation-induced shifts in the Charpy V-notch curves at the 30 ft∙lb, 50 ft∙lb, and 35-mil levels were measured. The decrease in the Charpy upper shelf energy was also measured. The largest temperature shift occured at the 35-mil level for all materials, and this shift was used to determine the adjusted reference temperature. The increase in reference temperature ranged from 140°F (60°C) for the base metal to 345°F (174°C) for the weld metal. The weld metal also showed the largest drop in the Charpy upper-shelf energy (44 percent) versus 23 to 31 percent for the other materials.

The critical beltline material for determining the new operating limit curves for the reactor was the weld metal, with an adjusted reference temperature of 315°F (157°C) and a Charpy upper-shelf value of 57 ft∙lb. The high copper and phosphorus content of the weld (0.36 percent copper, 0.015 percent phosphorus) caused the irradiated Charpy data to fall above the general trend curve for Type A533B steel. A trend curve for the weld metal was constructed using independently generated irradiation data on the same weld metal.
Displacement Spike Annealing in Iron at Reactor Temperatures
Authors: Beeler JR , Beeler MF
Published: March 2009

Displacement spike annealing computer experiments were done for body-centered cubic (bcc) and face-centered cubic (fcc) iron using five different annealing models. Each model predicted a greater number of free interstitials than free vacancies. The number of annihilation events was increased by an increase in cluster migration and decreased by an increase in the clustering interaction radius. The largest number of surviving defects occurred when clusters of four or more defects were immobile and a small clustering interaction radius was assigned.
Neutron Displacement Damage Cross Sections for Structural Metals
Authors: Doran DG , Graves NJ
Published: March 2009

Irradiation test data on reactor structural materials should include, in addition to fluence, the displacing dose expressed as displacements per atom (dpa) or damage energy per atom (depa). This provides a spectrum-dependent parameter that serves as a starting point for data correlations, as well as an exposure unit that is common to both neutron and charged-particle irradiations. To make this possible, displacement damage cross sections for neutrons have been calculated for aluminum, vanadium, chromium, iron, nickel, copper, zirconium, columbium, molybdenum, tantalum, tungsten, lead, and stainless steel using evaluated nuclear data files (ENDF/B-IV) data and the Lindhard energy partition model. These data extend to 20 MeV, hence cover the energy ranges of primary interest for both fission and fusion reactor applications. Tables are given in a standardized energy group structure. Figures are included to show the relative contributions of the various neutron scattering processes to both the primary knock-on atom spectra and the damage cross sections. A brief description of calculational procedures is given.
Bedding and Backfilling of Buried Pipe Conduits
Authors: Spangler MG
Published: March 2009

Rigid pipe sewer and culvert installations are frequently weakened by failure to install the pipe in a high-quality bedding which will laterally distribute the upward reaction on the bottom of the pipe. If the reaction is caused to be concentrated, the bending moment in the pipe wall is seriously increased, and failure in the form of cracking or spalling may result.

Another construction feature which may lead to difficulty is failure to place the sidefill soil in intimate contact with the sides of the pipe. Every pound of active lateral pressure which can be brought to bear against the sides of the pipe increases its ability to carry vertical load practically one for one.

The writer indicates that a pipe on a high-quality bedding with favorable conditions for the development of active lateral pressure on the pipe sides will carry approximately 2½ times as much load as the same pipe on a poor-quality bedding with no opportunity for side pressure to develop.
A New Design Method for Buried Concrete Pipe
Authors: Parmelee RA
Published: March 2009

Utilizing the results from an extensive parametric study of various soilpipe systems as obtained from the comprehensive computer program NUPIPE, a simplified method for the design of buried concrete pipe has been developed. This paper presents the basis and development of this system design approach which yields realistic results, yet is simple and easy to use. The design method can be carried out with the aid of a pocket electronic calculator, and the design equations can be programmed for a minicomputer, or a programmable pocket calculator.
Application of Fractographic-Microstructural Correlations in Evaluating Failure Mechanisms in Two Types of Steels
Authors: Steele JH , Lentz DF
Published: March 2009

Steel alloys exhibit a variety of fracture mechanisms depending upon their composition, heat treatment, degree of cold working, and environmental and stress conditions. Determination of the operative mechanisms from fractographic features requires that comparisons be made between observed features and those which are characteristic of cleavage, ductile rupture, or intergranular or hydrogen embrittlement. In most cases this involves generating controlled laboratory fractures under conditions which will produce each type individually. In addition, a correlation of microstructural and fractographic features must be obtained to characterize these different mechanisms. Illustrations of these two important aspects of fractographic analyses will be presented for fracture processes occurring in drawn cup walls of low carbon sheet steel and in bending tests of a quenched and tempered plate steel.
Fractographic Analysis of Low Cycle Fatigue Specimens from a Failed Steam Turbine Rotor
Authors: Kramer LD
Published: March 2009

Because the TVA Gallatin Number 2 steam turbine rotor burst resulted from creep-low cycle fatigue interaction, the present study was undertaken to establish the effect of strain range, increasing hold times, and degree of segregation in the intermediate temperature range corresponding to Gallatin origin conditions. Manganese-sulfide (MnS) inclusions were found to be preferential initiation sites independent of hold-time duration, surface oxide spiking, and most strain ranges, but no significant decrease in specimen cyclic lives was observed to occur with variable MnS concentrations corresponding to different locations in the rotor. Fractographic simulation of the Gallatin origin was obtained by imposing a 23-h hold time on bore segregated material at 427°C and a 2.98 percent strain range. Periphery material or decreasing hold times to a 4-h cycle caused a change from intergranular to transgranular fracture at 427°C. When selected hold-time tests were interrupted at less than 20 percent of expected cyclic life, early cracking was observed with the largest MnS linkup distance occurring in bore segregated material.
Strength, Toughness, and Flaw Tolerance of 25.4-mm (1-in.) Alloy Steel Lifting Chain
Authors: McCartney RF , Pellegrino JV
Published: March 2009

The interrelationship of strength, toughness, and flaw tolerance of 25.4-mm (1-in.) alloy steel lifting chain procured from five chain manufacturers has been investigated. Both International Standards Organization (ISO) Grade 63 and Grade 80 chains were tested. The susceptibility of these chains to sudden fracture in service in the presence of flaws is of interest to producers and users, and it was anticipated that the results would be helpful in arriving at a recommended upper limit of strength consistent with safety, inspection, and economic considerations.

Small round-bar tension-test and Charpy impact-test specimens were machined from each chain to characterize the materials. Fracture-mechanics calculations of critical flaw sizes then were conducted by using a Charpy-KIc correlation. The results showed that the Grade 80 chain, having a Rockwell C hardness (HRC) of 40, is susceptible to brittle fracture in the presence of small flaws. Tension tests on specimens from chain samples containing machined flaws 2.54 mm (0.1 in.) deep confirmed the calculations. Grade 80 chain containing the machined flaw fractured at less than half the load required to break unnotched chain; however, Grade 63 chain, having a HRC of 33, was virtually unaffected by the presence of a 2.54-mm (0.1-in.) deep flaw.
Effect of the Amount and Shape of Inclusions on the Directionality of Ductility in Carbon-Manganese Steels
Authors: Takada H , Kaneko K , Inoue T , Kinoshita S
Published: March 2009

The present work has been made to elucidate the quantitative effects of the amount and shape of inclusions in carbon-manganese steel plates on the tensile and impact ductilities in connection with test directions.

The influence of rolling conditions on ductility can be expressed as a function of the shape parameter of the inclusions in terms of the aspect ratio of elliptical manganese sulflde on the polished surface.

Tensile and impact ductilities in transverse and through-thickness directions were improved by rare earth metal (REM) additions to such an extent that the ductilities of REM-treated steel specimens were nearly the same as those of the REM-free steel specimens, although the inclusion content of the former was as much as two or three times more than that of the latter.

Efforts were made to express ductility in one parameter regardless of the inclusion shape and test directions, and it was found that the ductility was closely related to an inclusion area fraction on the ductile fracture surface.
Fracture Properties of a Cold-Worked Mild Steel
Authors: Ripling EJ
Published: March 2009

An AISI 1018 steel was rolled various amounts between 0 and 50 percent, after which it was partially stress relieved, and the following properties measured: smooth tensile, Charpy V-notch versus test temperature, fracture toughness, stress corrosion cracking susceptibility, and fatigue crack growth rate.

The yield strength was increased almost three-fold by rolling, and the upper-shelf Charpy V-notch toughness was reduced to approximately one third its unrolled value. The fracture toughness was only moderately changed, and the crack growth rate in fatigue (da/dN) unchanged by rolling. There was no subcritical crack growth in distilled water on sustained loading to KI values just less than KIC for periods up to 64 h; however, da/dN in distilled water was higher than its dry value if fatigue loading was slow.
Correlation Between Fatigue Crack Propagation and Low Cycle Fatigue Properties
Authors: Majumdar S , Morrow J
Published: March 2009

Fatigue crack propagation is treated as a succession of fatigue crack initiation events. The cyclic stress and strain experienced by elements ahead of the crack tip are computed by means of an elastic-plastic analysis and the cumulative fatigue damage is evaluated from low cycle fatigue properties of the metal. If it is assumed that the appropriate element width is related to the microstructure size of the metal, a significant deviation from the log-log linear relationship usually assumed to exist between the crack propagation rate, da/dN, and the stress intensity range, ΔK, is predicted. The analysis indicates that at small values of ΔK, da/dN rapidly decreases until it approaches zero at a “threshold” value of ΔK.

Fatigue crack propagation data for eight steels from Barsom's work are compared with predictions from the analysis using low cycle fatigue properties and values of the microstructure size based on Gurland's correlation between yield strength and the dimensions of the microstructural units responsible for strengthening in steels. In all cases the estimate of da/dN for a given ΔK was within a factor of two of the measured values.
Effect of Stress Concentration on Fatigue-Crack Initiation in HY-130 Steel
Authors: Barsom JM , McNicol RC
Published: March 2009

The useful fatigue life of structural components is determined by the sum of the elapsed load cycles required to initiate a fatigue crack and to propagate the crack from subcritical size to critical dimensions. Thus, to predict the service life of many steel structures and to establish safe inspection intervals, an understanding of the fatigue-crack-initiation and fatigue-crack-propagation behavior in steel is required. In the present study, the fatigue-crack-initiation life in HY-130 steel was investigated by testing specimens having widely varying notch acuities. The variation in notch acuity covered the range from fatigue-cracked specimens to polished, unnotched specimens, and fatigue-crack-initiation data were obtained in the range 103 to 106 cycles. The data were analyzed by using linear-elastic fracture-mechanics concepts and the theory of stress concentration in notched specimens.

The results showed that the number of elapsed load cycles required to initiate a fatigue crack in a notched specimen is related to the ratio of the fluctuation of the stress-intensity facor, ΔKI, to the square root of the notch-tip radius, ρ. Fatigue-crack-initiation life can also be expressed in terms of the fluctuation of the maximum stress at the notch tip, Δσmax, because ΔKI/√ρ can be related to Δσmax. Moreover, preliminary observations suggested that the fatigue-crack-initiation threshold in martensitic steels of various yield strengths tested under zero-to-tension load fluctuation can be predicted by the equation ΔKσysρ=0.6 is the 0.2 percent offset yield strength.

By using a weakest-link statistical model, it was shown that surface irregularities can appreciably decrease the fatigue-initiation life of structural components.
Evaluation of the Fatigue Crack Initiation Properties of Type 403 Stainless Steel in Air and Steam Environments
Authors: Clark WG
Published: March 2009

Fatigue crack initiation data were generated for Type 403 martensitic stainless steel in laboratory air and oxygenated steam environments. Tests were conducted with 1-in.-thick blunt notched compact tension specimens and the results analyzed and expressed in terms of both fracture mechanics and maximum stress parameters.
Rapid Calculation of Fatigue Crack Growth by Integration
Authors: Brussat TR
Published: March 2009

A procedure is described for drastically reducing the computation time in calculating crack growth for variable-amplitude fatigue loading when the loading sequence is periodic. By the proposed procedure, the crack growth, r, per loading period is approximated as a smooth function and its reciprocal is integrated, rather than summing crack growth cycle by cycle. The savings in computation time result since only a few pointwise values of r must be computed to generate an accurate interpolation function for numerical integration. Further time savings can be achieved by selecting the stress intensity coefficient (stress intensity divided by load) as the argument of r. Once r has been obtained as a function of stress intensity coefficient for a given material, environment, and loading sequence, it applies to any configuration of cracked structure. Any of a broad range of prediction models (such as “retardation models”) may be used in conjunction with the proposed procedure. Agreement with results obtained using cycle by cycle summation is demonstrated, for two retardation models.
Adhesion Measurement: Recent Progress, Unsolved Problems, and Prospects
Authors: Mittal KL
Published: March 2009

In this paper, the term “basic adhesion” is used to signify the summation of all interfacial intermolecular interactions, whereas the term “practical adhesion” is used to represent the forces or the work required for the disruption—either at the interface or in the interfacial region—of the adhering system. There are many factors which influence practical adhesion, and these are discussed in detail. The relationship between practical adhesion and basic adhesion is discussed. Basic adhesion cannot be determined by the commonly used techniques for measuring practical adhesion. The virtues of an ideal practical adhesion test are outlined. Some of the techniques for adhesion measurement of thin films, thick films, and coatings are discussed briefly, and references are made to the recent reviews on this topic.

For a given adhering system, different techniques yield different practical adhesion values. The difficulties involved in adhesion measurement are highlighted, and the unresolved problems are brought into sharper focus.

The failure surfaces should be examined using surface analytical tools to ascertain the locus of failure, which is important in understanding the mechanism of failure.
Thin-film Adhesion and Adhesive Failure—A Perspective
Authors: Mattox DM
Published: March 2009

A practical definition of “good adhesion” is that the interfacial region (or nearby material) does not fail under service conditions nor at unacceptably low stress levels under test conditions. Adhesion is a macroscopic property that depends on the chemical and mechanical bonding across the interfacial region, the intrinsic stress and stress gradients, and the adhesive failure mode. The failure mode depends on the interfacial structure and the stress to which the interface is subjected. Good adhesion is promoted by: (1) strong bonding across the interfacial region, (2) low stress gradients, either from intrinsic or applied stress, (3) absence of easy fracture modes, and (4) no long-term degradation modes. Adhesion testing must take into account the possible deformation and fracture modes, and a testing program must be devised to test all aspects of adhesion.
Measurements of Film-Substrate Bond Strength by Laser Spallation
Authors: Vossen JL
Published: March 2009

Laser spallation is a technique for detaching thin films from substrates by impinging a pulsed, high-energy laser beam onto the back side of a substrate (made opaque in the case of transparent substrates). The explosive evaporation of absorbing material on the back side sends a recoil compressive shock wave through the substrate toward the film-substrate interface. The substrate then snaps back in tension. Threshold values for film detachment can yield information about the film-substrate bonds without contact with or disturbance of the film surface. Thus damage propagated to the interface from film surface disturbance is eliminated. In some cases it is possible to examine [for example, by Auger electron spectroscopy (AES)] the spalled dot and the region of the substrate from which it was spalled to determine the locus of failure and to obtain information about interface formation.
Adhesion Measurement on Thin Evaporated Films
Authors: Kuwahara K , Hirota H , Umemoto N
Published: March 2009

Methods to evaluate the adhesion of thin evaporated films to their substrate were devised. One was to pull down and the other to twist off a rod whose bottom was cemented with epoxy to the film. The critical force or torque to strip off the film from the substrate was taken as a measure of the adhesion. It was important to maintain adequate temperature and humidity [16 °C (61 °F) and below 60 percent] during the cementing and measurement, to assure the high adhesion of the cement and the reproducibility of the result.

The adhesion of thin films of aluminum, silver, and copper to substrates of mild steel and glass was studied, along with the adhesion of epoxy and other cements. It was found that the critical force and torque were proportional not to the 3rd power as expected but rather to the 2.5 ∼ 2.9th power of the rod diameter. In the case of thin films, the dispersion of the measured values was very large. The dispersion and also the ratio of tensile to shear adhesive strength increased rapidly with the decrease in adhesion. This is contrary to the effects of the small dispersion, the independence of the dispersion, and the ratio on the adhesion in the case of cement itself. Also mentioned is an experiment on the fracture of brittle substrates such as silicon wafers which sometimes happened during the measurement.
Adhesion Measurement Technique for Soldered Thick-Film Conductors
Authors: Leven SS
Published: March 2009

This paper describes the results of an experiment to determine practical screening and quality-assurance procedures to preclude excessive adhesion degradation, due to solder leaching, in gold alloy/solder systems in thick-film hybrid microcircuits. These results include a comparative rating between the materials tested, along with criteria for rating different materials.

Four environmental stresses were compared to determine which one to use as a quality-assurance test for adhesion decay. The test method consisted of soldering copper pins to conductor pads on the substrate, and then pull-testing the pins to the destruction of the conductor/substrate bonds, both before and after environmental stresses. This method provides a measurement of both tensile adhesion between the soldered conductor and the substrate and adhesion degradation promoted by the environmental stress.

Seven thick-film conductor materials and three solder compositions were used, making a total of 21 conductor/solder systems tested. Pins were soldered to each of the seven conductor materials with each of the three solders. Adhesion measurements were made immediately, again after a minimum three-day shelf life, and also after each environmental stress. The median force-per-unit-area values for each conductor/solder/environmental stress combination were tabulated and plotted. The results are presented to show the relative degradations of the different materials.

Based on the results of the experiment, the temperature cycling stress appears to be the most practical stress to use as a screening procedure for solder leaching. Guidelines are presented for performing the screening test and for determining a rating for any material combination.
Adhesion of Flame-Sprayed Coatings
Authors: Ingham HS
Published: March 2009

The ASTM Test for Adhesion or Cohesive Strength of Flame-Sprayed Coatings (C 633-69) is a bond test consisting of coating a flat end face of a 2.5-cm-diameter rod of substrate material, attaching this coating with an epoxy adhesive to the face of another rod, and subjecting the assembly to tensile load normal to the plane of the coating. Flame-sprayed coatings include wire, rod, or powder sprayed by combustion flame, plasma spray, arc gun, and detonation processes. Bond strengths of such coatings range from about 0.05 N/m2 to greater than 0.7 N/m2. A problem with the test method is a tendency for some adhesives to penetrate the porosity of these coatings and thereby influence strength results. An attempt to determine adhesive penetration by testing different thicknesses of coating is described. Tests of bond strength versus thickness of the thinner coatings gave erratic results. To avoid penetration the procedures require a coating thickness minimum of 0.4 mm, and there is a list of recommended adhesives in the standard method. Other related test procedures, as well as round-robin testing which led to the prescribed procedures of ASTM Method C 633-69, also will be described.
Adhesion Testing of Deposit-Substrate Combinations
Authors: Dini JW , Johnson HR
Published: March 2009

For quantitative measurements of adhesion in coating-substrate combinations, the means most often used at Sandia Laboratories are ring shear, conical-head tension, and I-beam tension tests. Details presented for each test include specimen size, shape, and preparation, and the manner in which the test is performed. The pros and cons of each test are discussed in the light of substantial practical experience, and data for the various deposit-substrate combinations are included.
Testing to Determine the Effect of High-Pressure Hydrogen Environments on the Mechanical Properties of Metals
Authors: Chandler WT , Walter RJ
Published: March 2009

Equipment and procedures used in performing tension, fracture mechanics, fatigue, and creep tests on metal specimens in high-pressure hydrogen are described. Important test parameters, in particular, hydrogen purity and methods of achieving high purity are considered. The interpretation and use of data obtained from the various tests in high-pressure hydrogen are discussed.