bluuebunny/crossref_metadata_2025 huggingface dataset:
Calibration Techniques
Authors: Nelson GO
Published: March 2009

Preparing known concentrations of gas and vapor in air is an important function of any industrial hygiene laboratory. In this paper two systems for generating gas or vapor mixtures are compared: the simple static system and the more complex dynamic system. A completely automated dynamic system that controls the flow, temperature, humidity, and concentration of a gas or vapor mixture is also described.
4000 Years of Sheet Metal Forming
Authors: Pearce R
Published: March 2009

The whole spectrum of sheet metal forming from 3500 B.C. to the present day is reviewed briefly.
Hot Forming of Aluminum-Magnesium Alloy Sheet
Authors: Painter MJ , Pearce R
Published: March 2009

A range of aluminum-magnesium alloys (2 to 6 percent magnesium) have been deformed in uniaxial tension over the temperature range 300 to 500°C (572 to 932°F) and substantial increases in ductility have been demonstrated. Grain growth, however, limits ductility in the 2 percent magnesium alloy, while cavitation limits it in 6 percent magnesium alloy. It is suggested that dynamic recovery and perhaps a contribution from dynamic recrystallization are the metallurgical mechanisms responsible for this behavior.
A Method for the Determination of Ductility for Thin Metallic Materials
Authors: Engelmaier W
Published: March 2009

A method to determine the ductility of metallic foils, coatings, and films, either unsupported or as a layer in a thin composite with some carrier substrate, is described. The technique is based on a novel use of low-cycle fatigue concepts together with a fatigue ductility flex tester which subjects specimens to cyclic bending over mandrels to precisely controlled strains. This method yields the fatigue ductility which closely correlates to the true tensile fracture ductility. The technique is also useful for generic specifications, accelerated testing, and process parameter evaluations.
Stainless Steel Castings in New York City Water Tunnel No. 3
Authors: Andersen GA , Goldspiel S
Published: March 2009

Construction of the New York City Water Tunnel No. 3, designed to carry 7.5 million m3 (two billion gallons) of water per day, involves many state-of-the-art technological considerations. This also applies to metallurgical aspects involved and especially those related to stainless steel castings, which are used in large valves 914, 1219, and 2438 mm (36, 48, and 96 in.) in diameter and in their 2438-mm (96 in.) flowmeter components. These entail considerations of long-term corrosion resistance plus demanding dimensional stability over long periods of time and compromises that need not usually be considered for other high-quality stainless steel castings applications, such as chemical plant pressure vessel components.

This paper summarizes specific Bureau of Water Resource Development experiences and decisions reached during its work on the large butterfly valves.
Intergranular Stress-Corrosion Cracking Resistance of Austenitic Stainless Steel Castings
Authors: Hughes NR , Clarke WL , Delwiche DE
Published: March 2009

This paper evaluates the resistance to intergranular stress-corrosion cracking (IGSCC) in the boiling water reactor of several grades and compositions of austenitic stainless steel castings. A specific objective of this work was to predict the performance of Alloy Casting Institute CF3, CF3A, and CF8 castings in nuclear applications. Full-size welded pipe tests were performed on 10.16-cm-diameter (4 in.) centrifugal castings and small-specimen tests were performed on isothermally treated static and centrifugal castings. The environment for both series of tests consisted of oxygenated high-purity water at 288°C (550 ± 10°F). Axial loads were applied to the full-size pipes in a trapezoidal time-load wave shape with the peak stress exceeding the 288°C (550°F) yield strength of the material tested. For the small-specimen tests, either a constant-extension-rate test technique, a constant-load test technique, or a variable-load test technique was utilized. Both the pipe test and small-specimen tests consistently produce IGSCC in susceptible material such as sensitized AISI-304 stainless steel. Test results clearly indicate the influence of carbon content and δ-ferrite in determining IGSCC susceptibility of austenitic stainless steel castings in the aforementioned environment. Both low carbon content and the presence of critical quantities of ferrite in CF3, CF3A, and CF8 cast material are shown to promote high resistance to IGSCC. In contrast, AISI-304 with essentially zero ferrite (comparable carbon content to CF8) fails by IGSCC when tested similarly.
Electroslag Casting of Stainless Steel Valve Bodies
Authors: Mitchell A , Sidla G , Gupta D
Published: March 2009

The electroslag casting (ESC) process has been widely used in the Soviet Union for the production of stainless steel components. In this work we present the results of an examination of the ESC process for the production of stainless steel valve bodies. The 300-kg valve castings were made at the University of British Columbia and tested by nondestructive and destructive methods. We conclude that although this technique offers distinct quality and production advantages, there may be difficulties in reconciling the method with present code qualification requirements.
Ferrite Measurement and Control in Cast Duplex Stainless Steels
Authors: Aubrey LS , Wieser PF , Pollard WJ , Schoefer EA
Published: March 2009

Increased interest has been focused on the ability to predict and control the ferrite content of cast stainless steels with duplex austenitic/ferritic structures. To this end the interrelationship has been examined between the ferrite content in cast CF-type (19Cr-9Ni) stainless steels as estimated by optical microscopy, its magnetic response measured by the Magne-Gage and the Ferritescope, and its chemical composition. The range of ferrite contents examined extended from zero to 48 volume percent in casting sections measuring 27 mm (1 1/16 in.) in diameter to a maximum thickness of 152 mm (6 in.) in a step block casting.

Based upon these tests, statistical relationships were developed to compute the ferrite content from the chemical composition. In addition, calibration procedures were developed for measuring the ferrite content by means of the Magne-Gage and Ferritescope with traceability to the National Bureau of Standards Coating Thickness Standards. The effect of section size on ferrite content is discussed.
Effect of Residual Tin Levels on Mechanical Properties of 12.5Cr Stainless Steel Castings
Authors: Morykwas S
Published: March 2009

Alloy 12.5 percent chromium (AMS 5350, ASTM A 743; Grade CA 15) is a corrosion-resistant and heat-resistant alloy with which a broad range of mechanical properties may be obtained through thermal processing. It is readily hardened and tempering temperatures up to 732°C (1350°F) produce a broad range of strength coupled with good impact resistance.

This paper presents the problems encountered within master alloy preparation and castings resulting from such preparation, with mechanical properties meeting specification requirements but resulting in field failures upon impact. Specific details regarding the chemical and mechanical property evaluations of the contaminated material are described.

Controlled additions of contaminant (tin) of varying concentrations were made to laboratory melts and subjected to specification test requirements. Test results show the deleterious effect of tin on impact values with no change in results when compared with standard specification mechanical property requirements. A request for changes in chemical composition residual elements has been made with supporting test data.
A New Low-Carbon 16Cr-5Ni Stainless Martensitic Cast Steel
Authors: Niederau HJ
Published: March 2009

A new low-carbon 16Cr-5Ni stainless martensitic cast steel (S + C 4405) is presented as an advancement of CA6NM with improved corrosion resistance, excellent ductility, less susceptibility to hardening cracks, and good weldability, filling the gap between CA6NM and CF8M. The chemical composition is balanced so that a homogeneous microstructure consisting of annealed martensite with small amounts of δ-ferrite and finely dispersed austenite is obtained after hardening and tempering. Because of limited δ-ferrite, the impact values obtained correspond to CA6NM, and limited austenite still allows yield strength values comparable to those of CA6NM.

Due to its excellent ductility combined with good fabricability, the material is also suitable for cryogenic applications down to −200°C. Furthermore, favorable fatigue tests, and particularly test results in artificial seawater, show a remarkable improvement over CA6NM. Pitting- and crevice-corrosion tests by the International Nickel Co. multiple-crevice tetrafluoroethylene washer method suggest a corrosion resistance between that of CA6NM and CF8M and that this steel is suitable for seawater application in connection with cathodic protection. Stress-corrosion cracking in hydrogen sulfide-containing media was investigated according to the National Association of Corrosion Engineers Specification MR-01-75, and the resistance of 16Cr-5Ni under sour-gas conditions was found to be superior to that of CA6NM. The castability of this alloy was found to be favorable and comparable to that of CA6NM.

These characteristics are important for the following applications: offshore engineering, seawater desalination, chemical and petrochemical industries, shipbuilding, cryogenics, power generation, food industry, paper machine construction, and especially for pumps, compressors, fittings, centrifuges, waterturbines, and ship propellers.
Thermal Behavior of a Graphite/Epoxy Composite in the Subcured State
Authors: Blankenship LD
Published: March 2009

Thermal diffusivities for a T300/5208 graphite/epoxy system were calculated from thermal conductivity, heat capacity, and density. These thermal diffusivity data were then used along with an infinite plate model having the fibers oriented in the direction perpendicular to the heat flow to predict temperature profiles during the curing process.
In-Plane Behavior of a Ribbon-Reinforced Composite
Authors: Yeow YT
Published: March 2009

Experimental and analytical procedures are used to ascertain the inplane behavior of a class of ribbon-reinforced composites containing different combinations of ribbon width, pattern, volume fraction, and amount of ribbon overlap. The rationale and description of four types of unidirectional and cross-ply composites are also given. One of the objectives of this study is to determine whether the analytical tools, based on classical laminated plate theory, developed for filamentary composites are suitable for the characterization of unnotched ribbon-reinforced composites.

The experimental results of the principal properties of the unidirectional composites indicate that the materials are orthotropic. In the longitudinal direction, the response is not affected by the ribbon width, pattern, and amount of ribbon overlap: however, influences of these parameters are observed in the transverse and in-plane shear directions. The transverse-to-longitudinal ratios (E22/E11 and σ22/σ11, modulus and strength ratios respectively) of the laminates containing 1.27-cm ribbons were found to vary from 0.78 to 0.91 for the modulus and 0.67 to 0.78 for the strength, depending on the ribbon pattern used. Good overall correlations are observed between the off-axis results and analyses.

The axial stress-strain response of all cross-ply laminates is always between the longitudinal and transverse response curves. This averaging behavior of the cross-ply laminates is due to the substantial contribution of the 90-deg laminae to the axial response of the composite. Further in-plane studies on the cross-ply laminates indicate that the trends of the moduli and strengths, for laminates containing ribbons which are packed hexagonally, are parabolic with respect to the inclination of the 0-deg laminae and the axial load. For cross-ply laminates containing ribbons packed in a staggered manner, the properties may be assumed to be isotropic. The average axial-to-longitudinal ratios (Ex/E11 and σx/σ11) for the cross-ply laminate are 0.91 for the modulus and 0.82 for the strength. The correlations between experiment and analysis show that the predictions are generally conservative, especially in terms of strengths. This is primarily due to the presence of interlaminar reinforcing effects, which are not considered in the analysis. In addition, variations in stacking sequence do not affect the response of all the laminates tested. Based on macroscopic and microscopic observations of the fractured specimens and the results presented here, it would be conclusive to say that freeedge effects are substantially reduced when ribbon reinforcement is used.
Construction and Use of Toughness Maps in a Fracture Analysis of the Micromechanics of Composite Failure
Authors: Wells JK , Beaumont PWR
Published: March 2009

Analytical expressions are presented that predict the debonding and pullout lengths observed in brittle fiber composites. These characteristic lengths are combined with models of four toughening mechanisms to calculate the work of fracture of a composite. The results are presented as maps showing not only contours of toughness but also the dominant toughening micromechanism. The toughness is largely determined by six material parameters, each map demonstrating the combined effect of changing two of these simultaneously.

Maps are presented for glass-fibers in epoxy and carbon-fibers in epoxy. Their use is demonstrated by showing the effects of hygrothermal aging on the toughness of the composites.
Effects of Spectrum Variations on Fatigue Life of Composites
Authors: Badaliance R , Dill HD , Potter JM
Published: March 2009

This program was performed to evaluate the effects of load history variations on the durability of composite structures in order to outline procedures for developing load spectra for design and test. A total of 36 constant amplitude and 184 spectrum fatigue tests were performed. The test specimen was a simple center hole coupon made of AS/3501-6 graphite/epoxy prepregs. Two different layups, fiber dominated (48/48/4) and matrix dominated (16/80/4), were evaluated. The spectrum variations found to have greatest effect were those that increased the number or magnitude of the high loads in the spectrum. Addition of overloads caused more than an order of magnitude reduction in life. A 5 percent increase in test limit stress caused about 60 percent decrease in life. Variations found to have smaller impact on life were those that changed the lesser loads in the spectrum.
Stiffness Degradation of Fiber-Reinforced Composites under Uniaxial Tensile, Pure Torsional, and Biaxial Fatigue at Cryogenic Temperature
Authors: Wang SS , Chim ES-M , Socie DF
Published: March 2009

A study on stiffness degradation of glass fiber-reinforced composite laminates subjected to uniaxial tensile, pure torsional, and biaxial cyclic fatigue loading at cryogenic temperature is presented. The tensorial nature of stiffness change in the composite material is discussed first to establish a basis for fatigue experiments. Uniaxial tensile and pure torsional cryogenic fatigue tests were conducted to provide references for the study of more complicated multiaxial fatigue. Biaxial cryogenic fatigue under cyclic tension-torsion loading was then performed to examine the effect of complex states of cyclic stress. Stiffness deterioration in terms of changes of elastic constants during fatigue is studied for the cases of various loading conditions. The fundamental nature of cryogenic fatigue degradation in the composite material is investigated. Basic damage mechanisms and mechanics associated with the stiffness change during cyclic fatigue are discussed. Implications of the cyclic stiffness degradation on cryogenic fatigue failure and on the design and analysis of cryogenic composite structures and components are also discussed.
Fatigue Response of Composite Laminates with Internal Flaws
Authors: Gibbins MN , Stinchcomb WW
Published: March 2009

Quasi-static response and fatigue response under tension-tension loading, R = 0.1, to 106 cycles were evaluated for two laminate types. (±45/0)s and (90/0)s, of T300-5208. All laminates contained a longitudinal notch embedded in the 0-deg plies. Results were compared with previous fatigue studies of the same laminates with a transverse notch embedded in the 0-deg plies. Nondestructive investigation methods used to evaluate damage included acoustic emission, ultrasonic attenuation, C-scan, soft X-radiography, thermography, and stiffness change. Results show that damage initiation and growth depend more on laminate type than on notch orientation. Constraining plies of ±45 deg provided better interfiber splitting resistance and delamination resistance than constraining plies of 90 deg. All nondestructive investigation techniques showed good correlation throughout the testing.
Reinforced and Nonreinforced Reaction Injection Molding Machines for Production of Polyurethane Specimens for Material Development, Evaluation, and Quality Control
Authors: Schneider FW
Published: March 2009

This paper describes the principle of metering and impingement mixing of reaction injection molding (RIM) reactants. Efficient mixing is achieved at turbulent mixing conditions in the mixing chamber. Key factor is the Reynolds' number of the system, depending on the viscosities of the reactants, design, and size of the mixing device, arrangement of nozzles, etc. Mixing conditions are discussed at different ratios of reactants, introduction of additional fluid components to the mixing chamber, mixing of reactants with suspended solid fillers in accordance to reinforced reaction injection molding (RRIM) and lead lag phenomena. The basic requirements for the reactants are outlined for successful processing in accordance to the impingement principle, control of rheology of the initial mixture, effect of air loading, solid fillers, and aftermixing devices. The principles of some RIM and RRIM machines are demonstrated by examples as well as available laboratory RIM and RRIM machines with mold arrangements for the production of specimens under realistic conditions for material development and evaluation, followed by guidelines for aftermixer designs and gate configurations.
Equipment for Processing Microcellular Urethanes by the Reaction Injection Molding Process
Authors: Ashe WA
Published: March 2009

This presentation outlines the equipment requirements for processing microcellular and reinforced Reaction Injection Molding (RIM). The presentation will review the following areas: mixing and metering equipment, mix heads, neucleation devices, molds clamps, and molds.
Testing: Thermal Expansion of Reinforced and Nonreinforced Urethane Materials
Authors: Heckla WE
Published: March 2009

This paper reports factors that influence the determination of the coefficient of thermal expansion of reinforced and nonreinforced urethane materials.

The factors investigated were repeated test cycling of the specimen, additional post-curing, and preconditioning the specimens at various relative humidity levels. In addition, the results of an interlaboratory round robin program are presented to show the expected precision of the test method when the above factors are controlled.
Crack Initiation and Propagation Approaches to Fatigue Analysis
Authors: Nelson DV , Socie DF
Published: March 2009

Commonly used analysis methods for predicting “uniaxial” crack initiation and propagation lives in notched structural components are summarized. Experimental trends in the crack initiation and propagation behavior of notched laboratory specimens are presented and discussed in terms of the influence of such factors as notch stress concentration and stress gradient, nature of the loading, residual stress, etc. Conditions for which fatigue life tends to be governed by crack growth considerations are identified. A criterion for nonpropagating cracks is examined. Examples showing how design factors influence the selection of crack initiation or propagation approaches are given. Potential advantages of a better understanding of small crack behavior at notches are noted.
Maintenance Scheduling Based on Accumulated Crack Growth
Authors: Berens AP , Gallagher JP
Published: March 2009

Currently United States Air Force aircraft structures are inspected and maintained in accordance with a Force Structural Maintenance (FSM) plan. Because actual aircraft mission usage is different for each individual aircraft structure in a force of aircraft, the schedule for individual structural inspections and modifications is adjusted to account for differences in the crack growth accumulation rate. Scheduling adjustments are based on continuous direct or indirect measurements of a potential crack length through individual aircraft tracking.

The purpose of this paper is to describe (1) the logistics/maintenance environment in which the tracking program operates, (2) the crack length projection procedures embedded within the tracking program, and (3) the accuracy requirements for the procedures employed. Accuracy requirements are studied through an analysis of potential errors that are possible in the projections of calendar time to critical crack length. The analysis isolates the effect of potential errors in the estimate of current crack length and compares this component of the total error with those due to the unknown future flying rate and the unknown future stress environment severity. The method permits comparison of prediction precisions for competing tracking systems, and conversely, provides realistic accuracy goals for the development of new systems. Numerical examples are presented based on data from current tracking programs.
The Role of Servocontrolled Testing in the Development of the Theory of Viscoplasticity Based on Total Strain and Overstress
Authors: Krempl E
Published: March 2009

The rate-dependent properties of AISI Type 304 stainless steel and of the high-strength Ti-7Al-2Cb-1Ta alloy obtained with tension specimens using a servocontrolled testing machine at room temperature are discussed. Tests involve strain rates between 10−8 and 10−2 s−1, strain rate changes, relaxation periods, stress rates between 10−1 and 102 MPa s−1, and creep periods.

The viscoplasticity model based on total strain and overstress is introduced and shown to qualitatively reproduce the properties observed under strain control. The theory is then examined for its qualitative prediction under stress control, and it is found that the average creep rate need not increase with an increase in stress owing to the overstress (effective stress) dependence of the creep rate. Numerical experiments illustrate this property, which is then confirmed by real experiments.

The theory has two material functions representing work hardening and rate dependence. A method of determining the function representing rate dependence from strain rate change tests is discussed. For Type 304 stainless steel this function is represented by two equivalent expressions which can be used from static (10−8 s−1) to dynamic strain rates (103 s−1). A rate sensitivity factor M (akin to the m-factor used in materials science) is introduced. It is shown to vary with overstress or strain rate.
Determination of First and Second Order Work-Hardening and Rate-Sensitivity Coefficients for Oxygen-Free, High-Conductivity (OFHC) Copper and 99.99 Percent Aluminum
Authors: Christodoulou N , Jonas JJ , Canova GR
Published: March 2009

In order to provide data for process modeling, work-hardening and rate-sensitivity coefficients of the first and second order were determined for oxygen-free, high-conductivity copper and 99.99 percent aluminum. For this purpose, tension tests were carried out at room temperature and with constant rates of deformation varying from 5 × 10−4 to 1 s−1. In each test, a constant true strain rate was applied at the minimum cross-section of specially machined samples by means of a computer-interfaced, servo-controlled hydraulic testing machine. The work-hardening coefficient, H = (∂ ln σ/∂ε)˙ε, the rate sensitivity of the work-hardening rate, Bσ = (∂H/∂ ln ˙ε)σ, and the curvature term, C = −(∂H/∂ ln σ)˙ε, were determined from the flow curves of continuous tests. By performing strain rate changes at constant structure τ and measuring the immediate stress changes, the “instantaneous” rate sensitivity, M = (∂ ln σ/∂ ln ˙ε)τ, was also established. The dependence of the coefficients derived in this way on stress and strain rate is described. From the variation of M with σ and ˙ε, the coefficients P = −(∂M/∂ ln ˙ε)σ and Q = (∂M/∂ ln σ)˙ε were evaluated. It was determined that an additional strain of 0.2 had to be imposed on the sample to take it from the UTS condition (H = 1) to the condition H + Bσ = 1. The latter is associated with the onset of flow localization, and the additional strain of 0.2 is a measure of the retarding effect of Bσ on the flow localization process. To assess the effect of impurities, a Haasen plot (Mσ versus σ) was constructed, which indicated that the copper was solution hardened due to the presence of ≅200 ppm of Ag + Mg + S, while there was no effect of solutes in the aluminum.
Creep of Aluminum under Combined Longitudinal and Shear Stresses
Authors: Gacougnolle JL , Peltier JF , de Fouquet J
Published: March 2009

The creep behavior of aluminum in primary and secondary stages has been studied under combined stresses at about 473 K. A new creep machine was designed on which the specimen is free to rotate. Thus the rotation of the specimen in addition to its elongation could be observed during creep in tension. A small constant torque is added to the tensile load for limited periods. The response of the creep of aluminum to this new stress has been analyzed. The torsional anelastic strain observed is similar to the anelastic back flow in tensile creep. The evolution of the parameters of anelastic strain and the torsional plastic strain indicates the origin of a new process of deformation before the end of primary creep.
Specimen-Test Machine Coupling and Its Implications for Plastic Deformation Models
Authors: Holbrook JH , Swearengen JC , Rohde RW
Published: March 2009

A unified and detailed evaluation of the coupling between specimen and test machine is presented. It is demonstrated that an accurate formulation of the specimen/machine coupling relation requires exact additivity of elastic and plastic strain contributions, and that additivity is only possible with a specific set of definitions for these strains. When these definitions are implemented to ensure additivity, two strain-dependent terms in the coupling relation are identified that have been treated as constants in previous studies. One term is shown to account for the decreasing true total strain rate with increasing plastic strain at a fixed crosshead speed. The second term accounts for strain dependence of the combined specimen/machine modulus due to change in length and area of the specimen.

Several applications of the coupling relation are given that illustrate the importance of treating the specimen and test machine as a well-defined system when inferring information about plastic-deformation models from raw data. Topics covered include (1) effect of machine stiffness on work-hardening behavior, (2) variation of total and plasticstrain rate during tensile deformation, (3) effect of machine stiffness on stress relaxation behavior, (4) relationship between stress rates before and after a change in crosshead speed, and (5) deductions about mobile dislocation density from observed stress-time behavior.
Experimental Investigation of Nonelastic Deformation Emphasizing Transient Phenomena by Using a State Variable Approach
Authors: Alexopoulos P , Keusseyan RL , Wire GL , Li C-Y
Published: March 2009

This paper reviews the development of a deformation model based on a state variable approach for nonelastic deformation. The material parameters required can be determined by a combination of load relaxation and constant displacement rate tests. The experimental procedures, methods of data analysis, and the physical significance of the material parameters are discussed. The deformation model has been used to simulate a variety of deformation phenomena and has been compared with experimental data.
Some Critical Experimental Tests of the MATMOD Constitutive Equations with Respect to Directional Hardening and Cyclic Deformation
Authors: Miller AK , Ziaai-Moayyed AA
Published: March 2009

Cyclic torsion data on pure aluminum and Type 304 stainless steel have been generated recently that test several assumptions and predictions of the MATMOD equations (a unified, broad, phenomenological model for nonelastic deformation). Generally the new data support the model, but in at least one area they suggest a needed improvement. Firstly, the data show that when back stresses are measured by a Bauschinger effect technique (as opposed to the usual stress-drop method) the ratio of the steady-state back stress to flow stress is essentially a constant, independent of the flow stress level; this helps confirm a key assumption in the equations, but also suggests the need for an additional directionally-hardenable contribution to the strain rate. Secondly, strain softening is observed within some of the hysteresis loops, especially at large strain ranges after cyclic hardening; this is in agreement with predictions of the model. Finally, the peak back stresses observed at a given strain range are observed to increase along with the isotropic strength level; this behavior differs from that predicted by the constitutive equations.
Prediction of Stress-Strain Response under General Multiaxial Loading
Authors: Garud YS
Published: March 2009

This paper deals with verification of a mathematical model capable of predicting rate-independent elastic-plastic stress-strain response of materials subjected to general multiaxial loading. The model is based on the concepts of incremental plasticity and a new hardening rule. Its application to predict steady response is illustrated for the case of combined cyclic out-of-phase (nonproportional) axial and torsional loading. The predictions are presented in the form of computer-generated hysteresis loops showing axial and torsional stress-strain response. The predicted response is shown to be in good agreement with available test results on two metals. Capabilities, limitations, and extensions of the model are briefly discussed in relation to the observed and predicted response.
A Relationship Between Theory and Experiment for a State Variable Constitutive Equation
Authors: Stouffer DC , Bodner SR
Published: March 2009

A state variable constitutive equation that can be solved for the state variables can then be used to calculate the state variable histories from the stress and strain histories observed during an experiment. This was done using the Bodner-Partom flow equation for wrought René 95 at 650°C. The evolution equation was determined for a state variable that characterizes the resistance to plastic flow, and some properties of a damage state variable were established. Analysis of the tensile and creep data suggested that two different mechanisms were active during deformation. A limited number of experimental results were compared with the response calculated from the flow and evolution equations.
Deformation Microstructures and Mechanical Equations of State
Authors: Turner APL , Hasegawa T
Published: March 2009

Results of experiments involving various monotonic and cyclic deformation paths and annealing treatments are described. The results show that a state variable theory for constitutive behavior must be based on several independent parameters. Correlations which show that different mechanical responses may depend on the same state variables are discussed. Transmission electron microscopy (TEM) characterizations of the microstructures developed during the tests are reported. Some correlations between microstructure and mechanical behavior are shown, but other cases are reported where no correlation can be found.
Multiaxial Creep of Textured Zircaloy-4
Authors: Murty KL , Adams BL
Published: March 2009

Extremes of anisotropic multiaxial creep behaviors were considered by analyzing the strain rate ratios versus applied stress ratio for highly cold-worked stress-relieved and partially recrystallized Zircaloy-4 tubings. Power-law creep was modeled by using the upper-bound estimate with the assumption that prism, basal, and pyramidal slip modes are possible mechanisms. Experimental strain rate ratios were compared with those calculated by statistical averaging of crystallite behavior using the crystallite orientation distribution function (CODF). The experimental data on the stress-relieved material were in excellent agreement with the model predictions based on basal slip as the dominant deformation mode. Data on partially recrystallized material were in reasonable agreement with the predictions based on a combination of basal and prism slip modes.

These results are also correlated with the Von-Mises—Hill phenomenological description with appropriate contractile strain ratios (anisotropy parameters), R and P. The parameter R is relatively insensitive to partial recrystallization and is related to the basal pole angle. The P-parameter, however, is shown to be very sensitive to fabrication procedures and is greater than unity for well-annealed material with split prism pole distributions. As the amount of cold work increased, P-parameter decreased to well below unity.
Subsurface Variability—The Key to Investigation of Coral Atoll
Authors: Angemeer J , McNeilan TW
Published: March 2009

Coral atolls are one of the most complex and variable foundation environments in which carbonate materials are encountered. Unlike most terrigenous deposits where the presence of bedrock resolves most foundation problems, in coralline deposits loose particulate material or cavities can underlie rock. If, however, the subsurface profile is reasonably consistent, the bearing capacity of shallow foundations in these carbonates is good and can be evaluated with conventional analytic techniques. Hence, assessing the variability and adequately delineating the subsurface profile are key factors in field investigations. Since atolls are often remote, investigations consisting of a number of conventional borings are often sufficient for simple bearing structures. Driven probes to supplement limited boring data are potentially advantageous. For more complex structures, the behavior of atoll carbonates necessitates that field investigation requirements be evaluated for the specific project.
In Situ Electrical Resistivity Measurements of Calcareous Sediments
Authors: Hulbert MH , Lambert DN , Bennett RH , Freeland GL , Burns JT , Sawyer WB , Field P
Published: March 2009

A four-electrode resistivity probe was successfully designed for use in the upper layers of unconsolidated submarine sediments, with emplacement by vibratory driving. Measurements with this probe in calcareous sediments off the southeast coast of Florida indicate an average conductivity of 1.0 mho/m and a range of 0.4 to 1.4 mho/m.
Geotechnical Properties of Calcareous Rocks of Southern Florida
Authors: Saxena SK
Published: March 2009

This paper presents the geotechnical properties of young calcareous rocks of southern Florida. The rocks covered are Miami, Key Largo, and Fort Thompson limestones. The paper briefly details the formation and areal extent of the rocks and then evaluates several samplers for obtaining maximum recovery in a relatively undisturbed form. Evaluation of the properties is based on field and laboratory tests. The field tests included seismic refraction studies, downhole and crosshole wave velocity studies, and Menard Pressuremeter tests. The laboratory tests comprised index tests and strength and deformation evaluation tests. In addition to the usual unconfined compression tests, this investigation reports the results of the Ko-triaxial tests on the rock specimens.

The range of values for porosity, compressive strength, and modulus from various tests is presented. The discussion provides a rationale for the difference in values obtained from the tests. The suitability of various tests in providing a representative mechanical behavior is discussed.
Driven Piling in Calcareous Soils
Authors: Dougherty JJ , Hunt HW
Published: March 2009

Steel H-piles are a readily available means of providing structure support over deep calcareous formations. With knowledgeable design, cast steel tip protection, and competent field direction, H-piles can be driven through mixed formations to dependable bearing. Pipe, thin-shell, timber, or precast are less certain to reach bearing in good condition. Caissons can be used but are subject to overruns and delays in some formations. In many areas, pulled and load-tested piles have proved the value of the tip-protected H for difficult driving.
Laboratory Research in the Development and Testing of Inhibited Coolants in Boiling Heat-Transfer Conditions
Authors: Mercer AD
Published: March 2009

An investigation of the performance of corrosion inhibitors for ethanediol-based coolants for internal combustion engines and the development of test methods for studying the behavior of coolants in nucleate boiling conditions are described. Inhibitor formulations are reported which provide good protection to cast iron, an aluminium alloy, copper, brass and solder. Three types of test procedures involving high rates of metal-to-coolant heat transfer have been developed in which the effects of the composition, flow rate, pressure and temperature of the coolant and of the heat flux through the metal on the surface temperature of test specimens can be followed. Results are provided for a formulation consisting of sodium sebacate and benzotriazole and some comparisons made with an existing formulation.
Research and Development Efforts in Military Antifreeze Formulations
Authors: Conley JH , Jamison RG
Published: March 2009

The U.S. Army was convinced as early as 1941 that a composition type antifreeze was desirable. The Army's needs are much more complex and operating conditions more severe than the individual automobile owner's. Army vehicles must be in the best possible operating condition at all time. These vehicles may be sent to almost any part of the world, and have to be combat ready on short notice. Operating conditions can be severe, requiring both highway and off-highway operation. Heat loads on the vehicle's cooling system vary depending upon the loads being carried and the terrain over which they are required to travel.

Indiscriminate use of commercial antifreeze coolants could result in cooling system failure. Mixtures of two good antifreeze formulations could have a direct effect on the corrosion protection of cooling system metals. In combat situations this could be disasterous.
Use of Electrochemical Techniques for Corrosion Testing of Antifreezes
Authors: O'Brien EF , Hirozawa ST , Wilson JC
Published: March 2009

Two electrochemical techniques were used for corrosion testing of antifreezes. The first method, the galvanic test procedure, evaluates corrosion in galvanic bimetallic couples commonly found in automotive cooling systems. It identifies the anode (major corroding metal) in the couple, gives useful corrosion rates in as little as 24 h, and can generate corrosion rates as a function of time. Thus, more detailed data can be obtained more rapidly than with the standard glassware corrosion test, which gives only a weight loss measurement after two weeks of testing. Test results were compared for a number of antifreezes obtained with this electrochemical method and with ASTM Corrosion Test for Engine Coolants in Glassware (D 1384-70) and ASTM Simulated Service Corrosion Testing of Engine Coolants (D 2570-73). These results show good correlation between the methods but also point out some areas where the electrochemical method can give misleading data.

The second method, the resistance polarization method, determines the corrosion rate on a freely corroding metal and is thus used to evaluate corrosion of a metal not galvanically coupled to another metal. An example is shown in which this method was used in combination with the galvanic method to obtain information on a corrosion mechanism; that is, the effect of localized corrosion of one metal on the corrosion losses in a galvanic couple. An antifreeze was selected for which the corrosion losses from the ASTM D 1384 method did not correlate with the corrosion rate measured by the galvanic method. The corrosion rate determined by resistance polarization correlated much better with these weight loss results. This indicates that the mechanism is predominantly controlled by local corrosion processes, which account for the major portion of weight losses seen in the ASTM D 1384 method.

The patented corrosion cell used with the electrochemical methods was developed in the BASF Wyandotte laboratory and is designed to be versatile, rugged, and simple. It duplicates the anodic polarization curve for 430 stainless steel in 1.0 N H2SO4 obtained in the ASTM Standard Reference Method for Making Potentiostatic and Potentiodynamic Anodic Polarization Measurements (G 5–72).

A discussion on the usefulness of the electrochemical methods for testing antifreezes concludes the paper.
Chemical Properties as a Tool for Maintaining High-Quality Engine Antifreeze Coolants in the Marketplace
Authors: Yates TP , Siano M
Published: March 2009

Engine coolants, antirusts, and antifreezes have certain chemical properties which are useful for their identification and stability measurement. These properties include pH, ash, water content, reserve alkalinity, and chlorides. The ASTM test developed for each chemical property is discussed, highlighting the relative benefits of each. Application to products in the marketplace will include: assisting in developing new formulations, aiding in monitoring inhibitor depletion in corrosion tests, assisting in ensuring high quality production standards, assisting in settling customer complaints, aiding in classifying competitive products and assisting in identifying premium versus low quality antifreeze coolants.
Detecting Coolant Corrosivity with Electrochemical Sensors
Authors: Baboian R , Haynes GS
Published: March 2009

The corrosivity of engine antifreeze coolants depends on many factors including inhibitor concentration. Degradation of these antifreeze inhibitors occurs with time in service and therefore leads to increased corrosivity. This paper describes a low cost coolant sensor capable of detecting the corrosivity of engine coolant in-situ. The system is based on electrochemical principles and consists of a sensing probe, electronics package, and an indicating device. Electrochemical theory and supporting data for the system will be presented.
Evaluating the Corrosion Resistance of Aluminum Heat Exchanger Materials
Authors: Dorward RC
Published: March 2009

Exposure of a number of aluminum alloys to cyclic laboratory corrosion tests in modified ASTM corrosive water (ASTM Corrosion Test for Engine Coolants in Glassware (D 1384-70)) shows that metallographic cross-sectioning procedures are required for a meaningful assessment of performance. Simple weight loss determinations, by themselves, do not give an accurate measure of corrosion behavior when attack is localized as it normally is in aluminum alloys. Electrochemical tests are useful for assessing inhibitor effectiveness and galvanic corrosion effects. However, without a detailed correlation with the type and rate of actual corrosion mechanism (pitting, crevice attack, intergranular corrosion), they should not be used for lifetime predictions.
Limiting Factors in the Spectrophotometric Analysis of Minor Components of Blended Metal Powders
Authors: Javier-Son AC , Kachelmeier EJ , Reynolds GH
Published: March 2009

The accuracy of chemical analysis of minor components of blended metal powders is dependent on good mixing conditions, representative sampling, complete sample dissolution, and sensitivity of measurement system.

An accurate, precise, and sensitive analytical procedure has been developed which facilitates the use of large sample sizes of blended metal powders and overcomes the difficulties of sample dissolution. The technique involves homogenization of the metal blends by arc melting in an inert atmosphere and analysis of the resulting arc-melted button and slag by atomic absorption spectrophotometry. Methods of eliminating interferences in atomic absorption determinations are discussed. Mathematicial correction can be applied in lieu of slag analysis which cuts down the analysis time by 50 percent. A mechanism for slag formation is proposed.
Assessment of the Accuracy of Spectrophotometric Measurements and Methodologies
Authors: Burke RW , Mavrodineanu R
Published: March 2009

Modern day spectrophotometers are used to perform both relative and absolute transmittance or absorbance measurements. In order to discuss these two distinct functions, this paper is divided essentially into two parts. The first part discusses the instrumental parameters that must be verified in order to assure that the measurement is accurate and outlines the several types of National Bureau of Standards (NBS) standard reference materials (SRM) that are currently available, or in process, for performing these verifications. The second part of the paper focuses on analytical method accuracy and describes a number of spectrophotometric procedures that have been widely used at NBS with the belief that they produce accurate results. In instances where sufficient data exist, the accuracy of these procedures is reexamined by comparison of the spectrophotometric values with those obtained by the accepted definitive isotope dilutionmass spectometric method. The paper concludes with some projections on the possible future use of ultraviolet-visible absorption spectrophotometry as a practical, multielement technique.
Contamination Control in Trace Element Analysis
Authors: Zief M
Published: March 2009

Contamination problems inherent in analysis at the ultratrace (<1 µg/g) element level are reviewed. Suggestions for controlling systematic errors in the following parameters are offered: the sample, the laboratory, containers, and reagents.

The addition of the blanks contributed from each of these sources comprises the total analytical blank in an analysis. Inasmuch as high blanks invalidate most ultratrace analyses, reduction in the size and variability of the blank components is a major step in attaining higher accuracy.
The Quality of Analysis Depends on Written Procedures
Authors: Rowe WA
Published: March 2009

The quality of chemical analysis is seriously impeded when no written procedures are available. There is a gap in the traceability of the results between specimen submitted and results reported. Documentation of the analysis is incomplete. The recipient of the results, who must draw conclusions about his materials from those results, relies solely on the reputation of the laboratory or the analyst who made the analyses in judging the quality of the results. Written procedures close the quality gap by revealing the method by which the results were obtained.

In order to become accredited by an official agency, a laboratory must prove its ability to provide quality analyses. Proof includes qualified personnel, calibrated equipment, a system of records, and written procedures. Examples of accredited laboratories are those clinical laboratories licensed by the Center for Disease Control to accept human specimens through interstate commerce.

Useful written procedures include certain topics; among these are the scope or applicability and limitations, a list of materials, sampling practice, step-wise procedures, interpretations of results, and special forms to record the analysis. Each of these topics will be discussed.