bluuebunny/crossref_metadata_2025 huggingface dataset:
An Assessment of Reactor Pressure Vessel Irradiated Materials Considerations
Authors: Stahlkopf KE , Marston TU
Published: February 2009

Regulatory action has contributed almost 4% to the accumulated outage time of the nuclear plants. This translates into a loss of between $66 million and $280 million to the economy. Radiation-embrittlement-related regulatory actions and associated outages are predicted for the future. This paper evaluates the current regulations related to radiation embrittlement and discusses some of the current embrittlement issues. Weaknesses in the regulations are identified and recommendations for future research to overcome these weaknesses are presented.
Calibration of the Side-Grooved Modified Wedge-Opening-Load Specimen
Authors: LeFort P , Mowbray DF
Published: February 2009

The modified wedge-opening-load (WOL) specimen introduced by Novak and Rolfe is now commonly employed to establish crack growth rate and threshold of stress corrosion cracking KIscc data. The present paper is concerned with the stress intensity factor solution for this specimen with 10% side grooving. Finite element and experimental compliance studies were undertaken to define the stress intensity factor solution in terms of crack mouth opening displacement. The analytical and experimental results obtained were found to be in excellent agreement. The results also verify the use of Wilson's finite element stress intensity calibration of the T-type WOL specimen when the effect of the side grooves is accounted for.
Effect of Temperature on Stress Corrosion Cracking of 300M Steel
Authors: Ryder JT , Pickel FM
Published: February 2009

The effect of temperature on stress corrosion cracking of high-carbon 300M high-strength steel in deionized water was investigated. Tests were conducted with wedge-opening-load specimens at 0, 23, and 90°C. Stress corrosion crack growth rates above the stress corrosion cracking threshold KIscc were found to increase with increasing temperature and to be essentially constant at each temperature. The crack growth rates appeared to be described by an Arrhenius-type rate expression. The apparent stress corrosion cracking threshold KIscc at 23°C was approximately 12.1 MPa · m½ (11 ksi·in.½) and at 90°C, 16.5 MPa·m½ (15 ksi·in.½). At 0°C, KIscc appeared to be lower than at 23°C.
Computer-Controlled Decreasing Stress Intensity Technique for Low Rate Fatigue Crack Growth Testing
Authors: Saxena A , Hudak SJ , Donald JK , Schmidt DW
Published: February 2009

An automated test system utilizing computer control was developed to obtain crack growth rate data down to the fatigue crack growth threshold with a decreasing stress intensity technique and compact type specimens. The starting stress intensity range ΔK0 was chosen to yield crack growth rates in the range of 2.54 × 10−8 m/cycle (10−6 in./cycle) and subsequent values of ΔK are controlled to the equation ΔK = ΔK0 exp [C(a − a0)] (a0 and a are the initial and instantaneous crack lengths and C is a test variable). Crack length is continuously monitored by using the elastic compliance technique, thereby enabling ΔK to be decreased continuously. Comparison crack growth data were also obtained by the more conventional constant load amplitude or K-increasing method. Excellent agreement was observed between data obtained from the two procedures for a Society of Automotive Engineers 1045 steel at load ratios R of 0.1 and 0.5, an A356-T6 sand-cast aluminum alloy at load ratios of 0.1 and 0.8, and a 2219-T851 aluminum alloy at a load ratio of 0.1.
Frequency, Stress Ratio, and Potential Effects on Fatigue Crack Growth of HY130 Steel in Salt Water
Authors: Vosikovsky O
Published: February 2009

Fatigue crack growth rates over wide ranges of stress intensities (from threshold to nearly critical stress intensity) were measured on HY130 steel in 3.5% sodium chloride aqueous solution at several cyclic frequencies, stress ratios, and potentials. The growth rates are compared with reference data measured in laboratory air. The growth rate curves for both environments can be approximated by two linear sections converging at low stress intensity ranges to the same threshold, which depends only on the stress ratio. The upper parts of the lines with lower slopes converge again to the point where maximum stress intensity approaches its terminal value. As a result, the maximum environmental acceleration of crack growth appears at intermediate stress intensities, and it increases with decreasing frequency and potential. Data indicate a relatively low susceptibility of HY130 steel to corrosion fatigue. With increasing stress ratio R the fatigue crack growth threshold is shifted to lower stress intensity ranges by the same amount in both air and salt water environments. The effect of R on growth rate can be introduced into a power law expression.
Mechanical Properties in Bending at Elevated Temperature of High Strength Copper Alloy Flat Spring Materials
Authors: Fox A , Fuchs EO
Published: February 2009

The yield strength and modulus of elasticity in bending for several high strength copper alloy flat spring materials were determined in the temperature range 23 to 232°C (73 to 450°F) by both static and dynamic measurements. Results obtained by both methods are compared with those obtained by using a simple, short-time stress-relaxation test, and their applicability to the design of flat springs or connectors is discussed. The short-time stress-relaxation test is proposed as a simple acceptance test for flat spring materials. The alloys studied include one copper-nickel-tin alloy strengthened by spinodal decomposition (92% copper-4% nickel-4% tin), copper beryllium alloy (CA 172), copper cadmium alloy (CA 162), and copperiron-phosphorus alloy (CA 196). Long-time stress-relaxation data (2000 h) for the temperature range 23 to 232°C (73 to 450°F) confirm the observations made during the short-time relaxation tests, which showed that for extended service life applications springs made from either precipitation heat-treated CA 172 or appropriately aged 9244 alloy would operate satisfactorily at temperatures below 121°C (250°F) while those made from either of the other two alloys would not. Similar conclusions could not be drawn on the basis of bending yield strength.
Evaluation of Correction Methods for Determining Load-Independent Knoop Microhardness
Authors: Young CT , Rhee SK
Published: February 2009

The correction methods proposed in the literature for determining load-independent Knoop microhardness were surveyed. The methods were evaluated by using the results from seven samples and two testers. Adding a constant correction factor for each sample to the measured long diagonals to obtain the unrecovered diagonal lengths was found to be quite successful. The correction factor includes terms from elastic recovery, visibility error, and calibration error. This factor, when applied, corrects the elastic recovery in the diagonals and the systematic errors associated with the tester employed, and thus results in Knoop hardness numbers independent of load and tester, which can be taken as the true hardness. The correction factor is load-independent but varies with sample and tester.

Two methods in the literature, a trial and error approach and an extrapolation technique, were found to work equally well for the seven samples in determining the correction factors and the load-independent hardness numbers. The approach attempting to correct the applied load with a term representing the minimum indenting load proved to be unsatisfactory.
Interlaboratory Measurements of Amphibole and Chrysotile Fiber Concentration in Water
Authors: Chopra KS
Published: February 2009

This paper presents the results of an evaluation of high-magnification microscopic techniques used to analyze fiber contamination in water conducted by an ASTM Task Group under Subcommittee E04.11 on Electron Metallography. These techniques offer a feasible means of measuring relatively low levels of fiber contamination in environmental water samples. Other bulk-type methods lack the needed sensitivity and selectivity. The transmission electron microscope is the best basic instrument for the analysis, particularly when it is equipped with selected area electron diffraction and energy-dispersive spectroscopy capabilities. The mean fiber concentrations by different groups agree within a factor of two. The interlaboratory reproducibility of 50% can be expected in relatively clean water samples unless the concentration is low. In samples with high concentrations of interfering solids, the precision will not be as good. Interlaboratory reproducibility of 25% is as good as the method can provide. When applied on a broad scale there are variable and significant losses associated with the condensation washing of samples containing amphibole. The losses are low and less varible when condensation washing is used to prepare samples containing chrysotile.
Comparison of Cotton Fiber Fineness and Maturity on Air-Flow Instruments
Authors: Lawson R , Ramey HH
Published: February 2009

Fineness and maturity measures were compared on two groups of cotton samples tested with the Micronaire, Arealometer, and IIC-Shirley fineness/maturity tester; one group was also tested with the Causticaire and sodium hydroxide maturity methods. Most correlations of the various parameters were high for Group A samples composed of four cultivars of Gossypium hirsutum L. The correlations were usually lower for Group B, which was made up of three species and several cultivars. Comparable parameters from different instruments were not always on the same level because of different calibration standards and procedures. However, if the correlation between methods is high, one can move from one measurement to another with a regression equation.
Proportional Biaxial Cyclic Hardening of Annealed Oxygen-Free High-Conductivity Copper
Authors: Lamba HS , Sidebottom OM
Published: February 2009

Cyclic-dependent hardening of annealed metals is by now a well-known experimental phenomenon. The annealed metal, when cycled between equal tensile and compressive strain limits, develops increasing stresses with each strain reversal. However, most previous experimental work on cyclic hardening has been restricted to axial or torsional loading. In this investigation hollow circular cylinders of annealed oxygen-free high-conductivity copper were subjected to combined axial-torsional cyclic proportional strain histories. The stress-strain histories for different proportional strain paths were correlated on the basis of effective stresses and strains defined previously by Tresca and Mises, and the correlations using Tresca's definitions were shown to be more representative than those of Mises. Power law hardening constants were determined for each stress-strain reversal. The power law hardening constants for axial cycling were predicted with reasonable accuracy from the corresponding torsional constants by employing correlations based on Tresca's definitions of effective stresses and strains.
Improvement of Sheet Metal Strength by Localized Thermal Shocks
Authors: Trasi SR , Hsu TR
Published: February 2009

In two previous papers, the authors presented results of a new process of introducing beneficial residual stresses in a sheet metal strip containing a small circular hole by a single thermal shock applied over an annular region concentric with the hole. In this paper, it is shown that multiple thermal shocks over separate annular regions are considerably more advantageous in introducing such beneficial residual stresses in the same sheet metal and in permitting wider tolerances for such variables as locations, sizes of shock zones, and strengths of the shocks for desired degree of benefit.
Biaxial Analogs of Triaxial Stresses
Authors: Ehrenburg DO
Published: February 2009

In the case of composite materials such as concrete and natural rocks, fracture is resisted by internal friction, cohesion of the matrix, and adhesion at the interfaces. Although the behavior of an interface is clearly understood only when it is acted on by tensile forces, rock mechanics is primarily concerned with compressive forces. The apparent difficulty is circumvented by breaking down any given stress system into two components: an isotropic pressure and a tensile biaxial stress. The strength indicated by the latter component is precisely equal to that of the given stress system. Thus a condition of triaxial compression can be transformed into one of biaxial tension. An analysis based on this transformation indicates that the strength of composite materials in equal biaxial compression is considerably greater than in unconfined compression; this relationship becomes the keystone of a strength theory for composite materials.
A New Fixture for Fatigue Testing
Authors: Min BK , Raj R
Published: February 2009

A new type of fixture has been designed for low cycle fatigue testing. The fixture provides good alignment and reduces the setup time to a minimum. It is especially useful for testing at elevated temperatures. If specimens with uniform cross section in the gage length are used, then the need for a diametral strain gage is eliminated. The fixture is presently being used to measure low cycle fatigue crack growth in 316 stainless steel at elevated temperatures.
Compliance Correction for Determining Load-Line Energies for Compact Fracture Toughness Specimens
Authors: Server WL
Published: February 2009

A compliance correction technique has been used to calculate energies in the compact specimen test measured at the specimen loading line using the machine ram displacement. The compliance-corrected results for nine pressure vessel steels tested at temperatures of room temperature, 71°C, and 177°C have been compared with the direct measurement (standard clip gage) approach, and the results show essentially a 1:1 relationship with a correlation coefficient of 0.997. This technique should be useful for determining elevated temperature, ductile fracture toughness values and for tests in which the normal clip gage (or other technique) fails to operate.
A Modified Procedure for Measuring the Maximum Specific Gravity of Bituminous Paving Mixtures
Authors: Ishai I , Tons E , Chritz AP
Published: February 2009

An accurate measurement of the maximum specific gravity of bituminous paving mixtures Gmm is needed for a reliable air voids analysis of the mixtures in the design and control phases. Since most actual bituminous mixtures combine absorptive aggregates, some difficulties have been encountered with the use of some current procedures for measuring Gmm. This paper presents a procedure for measuring the maximum specific gravity with the use of methanol. The good wetting ability of the methanol, together with its insignificant dissolvent characteristic, enables it to be used as a volumetric liquid for realistic measurements of Gmm. These properties eliminate the difficulties in expelling the trapped air bubbles even without vacuum as well as ensure almost no asphalt dissolution and thus no penetration of liquid inside the aggregate surface voids that are impermeable to asphalt. In general, the test was found to be fast and simple, with highly repeatable results.
Strain Criteria for Fatigue Fracture of Metals at High-Cycle Loading
Authors: Troshchenko VT
Published: February 2009

The paper deals with the features of inelastic straining and fatigue fracture of metals in high-cycle loading. It is shown that the use of cyclic strains enables one to study the kinetics of cyclic deformation and fatigue damage accumulation with different loading histories, to consider the stress-strain state of structural elements with stress concentration, to formulate strain criteria for the fatigue fracture of metals involving various factors, and to develop methods for the accelerated determination of the fatigue limit.
Effect of Measurement Precision and Data Processing Procedures on Variability in Fatigue Crack Growth Rate Data
Authors: Wei RP , Wei W , Miller GA
Published: February 2009

Variability in experimental data on fatigue crack growth kinetics reflects contributions not only from material property variations and environmental and other uncontrolled variables but also from measurement precision used in determining the primary data (that is, crack length versus elapsed cycles) and the subsequent data processing procedures in determining rates from the primary data. To assess the contributions of measurement precision and data processing procedures to variability, computer simulation of primary fatigue crack growth data was made for a number of measurement intervals and precisions. These simulated data were analyzed by several data processing procedures.

Variability in the derived growth rate data was found to depend strongly on the magnitude of the measurement interval relative to the measurement precision. This variability was reduced by data processing procedures, such as incremental polynominal methods, that fitted a smooth curve through portions of the primary data. Such procedures, however, can introduce statistically significant bias into the derived data on crack growth kinetics; this bias may or may not cause large errors in predicted fatigue life. Because variability associated with crack length measurement interval and precision and with data processing procedures can be quite large and is incorporated in an unknown way into much of the published data on fatigue crack growth rate, caution should be exercised in drawing statistical inferences regarding material differences from such data. Suitable procedures that would allow assessment of material differences from experimental crack growth data need to be developed.
Statistical Analysis of Notch Toughness Data
Authors: Koons GF
Published: February 2009

In the usual method for analyzing notch toughness values only a few specific notch impact measurements are selected for experimental study. In obtaining these results, many of the experimental data are not used quantitatively. Some experimenters have used a four-parameter function, called the hyperbolic tangent, to summarize impact test data that can be assumed to follow an S-shaped pattern. The proposed method of analysis uses the parameters of this function rather than the actual impact test results to analyze changes in the notch toughness of metals. This method allows one to study the effect of the experimental variables on the shape of the entire curve rather than on one specific point on the curve. In addition, the curve parameters can be used to predict temperatures associated with any notch toughness measurement. An estimate of the variability of the prediction can also be calculated.
Application of Fatigue Life Prediction Techniques to Materials Substitution
Authors: Sherman AM
Published: February 2009

The applicability of a computer-based fatigue life predictive technique to materials substitution has been tested by performing a fatigue design analysis on an automobile frame crossmember. The original steel component and an alternate aluminum design were instrumented and installed in a test car, and the vehicle was driven over a standard rough road durability route to record road load histories. The recorded histories were used with a previously developed computer-based predictive technique to obtain component life predictions. Laboratory-program loading of samples of the two materials using the recorded histories confirmed the accuracy of the life predictions. Finally, by taking into account both material property differences and structural design parameters, it was shown that a service history obtained from one component can be used to predict the fatigue life of the component made of alternative materials. This procedure can be of significant value in the consideration of materials substitutions even in situations where design changes accompany the substitution.
Acoustic Emission Monitoring of High-Temperature Cyclic Oxidation Damage in a Titanium-Aluminum-Vanadium Alloy
Authors: Baram JC , Itzhak D , Rosen M
Published: February 2009

The feasibility of using acoustic emission techniques to monitor high-temperature thermal cycling oxidation damage in Ti-6Al-4V was studied between 600 and 900°C. Acoustic emission distribution analysis was applied to discriminate between different mechanical processes that lead to spalling of the oxide layers. It has been proven that acoustic emission follows very closely the exact material oxidation damage mechanism. Plastic deformation and partial stress relief in the oxide alloy system give rise to increasing emission of low peak amplitude pulses. Cracking and fracture of the oxide's scale, followed by spalling, produce a high rate of acoustic emission, with an increased fraction of high peak amplitude pulses. Nondestructive monitoring of oxidation damage in Ti-6Al-4V by acoustic emission was shown to be able to predict the onset of catastrophic spalling of the oxide's scale.
Three-Point Bending at Large Deflections of Beams with Different Moduli of Elasticity in Tension and Compression
Authors: Paolinelis SG , Paipetis SA , Theocaris PS
Published: February 2009

An analytical investigation of three-point bending at large deflections was carried out with materials exhibiting different moduli of elasticity in tension and in compression. It was found that the solutions developed by the authors elsewhere for equal moduli materials were still valid, provided that load and beam depths were replaced by equivalent values derived by multiplying the actual values by factors that were functions of the moduli ratio only. The moduli ratio, even for small deviations from unity, was found to influence the behavior of the system considerably. Interaction with friction at the supports could render experimental results unreliable, and hence complete knowledge of the reaction forces during the bending test, both by magnitude and direction, appears to be necessary. Experimental evidence appears to support the present theoretical predictions.
A Critical Evaluation of Pulse Collectors for Utilities
Authors: Jensen RM
Published: February 2009

Several types of fabric filters are used to remove fly ash from the products of combustion of large coal-fired power plants. This article compares two types of cylindrical bags: inside collectors and outside, or pulse, collectors. A synopsis of the evolution of the outside collector precedes a discussion of the merits and shortcomings of both types of collectors. Various claims made by adherents of outside collectors are then discussed. Finally, the costs of replacing bags in the two types of collectors are compared.
A Biaxial Fatigue Machine for Elevated Temperature Testing
Authors: Brown MW , Miller KJ
Published: February 2009

A biaxial fatigue rig has been developed to study failure under low cycle fatigue conditions. The tubular specimen can be subjected to axial load, torque, and internal pressure enabling a wide range of stress/strain states to be obtained under strain-controlled conditions. A four zone furnace has been developed for elevated temperature tests, while allowing strains to be measured from the gauge length.
Stress Intensity Factors for Single-Edge-Crack Solid and Hollow Round Bars Loaded in Tension
Authors: Bush AJ
Published: February 2009

Dimensionless stress intensity factors were determined for single-edge-crack solid and hollow round bars loaded in tension. These factors were calculated from experimental compliance (inverse slope of load-displacement curve) measurements made over a range of dimensionless crack depths (lengths) from 0.05 to 0.65. The tests were made with 76-mm (3-in.) diameter solid and hollow round bars notched on one side and loaded in axial tension. The hollow bar had an inner to outer diameter ratio of 0.33. A comparison was made with data in the literature for rectangular bars; for a crack depth to diameter ratio of 0.0001 the dimensionless stress intensity factor for a solid round bar is 0.55 compared with 2.0 for a rectangular bar.
Stress-Strain Characteristics of Reinforcing Steel Bars Under Cyclic Loading
Authors: Desayi P , Iyengar KTSR , Reddy TS
Published: February 2009

This paper presents test results for 22 high strength deformed bars and nine mild steel bars subjected to monotonic repeated and reversed axial loading to determine the stress-strain behavior. Equations have been proposed for the stress-strain curves and have been compared with test results. Satisfactory agreement was obtained.
Truncated Sequential Sampling Plan for Use in Determining the Grade of Wool
Authors: Reals HC , Muse D
Published: February 2009

The objective of average fiber diameter measurement is to determine the grade of a lot of wool with a reasonable degree of certainty. A sequential sampling plan for each of the 16 U.S. Department of Agriculture (USDA) grades of grease wool was developed in an effort to reduce the minimum number of fiber measurements specified for grade determination. The sequential sampling plan was applied to 61 samples representing 14 USDA grades of grease wool. Forty-four (72%) of the samples were determined to be in the proper grade on a sequential basis before the currently prescribed minimum number of fibers were measured.
Reliability of Results of Analyses After Multiple Testing of Petroleum Products
Authors: Zanker A
Published: February 2009

A formula for the estimation of the reliability of analyses after multiple testing of petroleum products was developed and published as ASTM Standard Practice for the Utilization of Test Data to Determine Conformance with Specifications (D 3244-77). A nomograph included in this paper allows the solution of the complicated formula easily, quickly, and with reasonable accuracy.
A Rapid Test for the Assessment of Steel Sheet and Tinplate Properties
Authors: Ludwigson DC
Published: February 2009

The “RAPID-n” test is capable of measuring accurately the yield and ultimate strengths, elongation, strain-hardening exponent, and strain ratio of steel sheet, tinplate, and other sheet materials in less than 5 min from sample reception. Five units are now in service.
Fitting Curves to Toughness Data
Authors: Oldfield W
Published: February 2009

Curve-fitting (regression) procedures for toughness data have been examined. Approaches using the normal probability function and the tanh function to model the transition between brittle and ductile behavior have been briefly reviewed. The objectives of fitting such curves have been summarized in the context of the study of nuclear pressure vessel steels as (1) convenient summarization of test data to permit comparison of materials and testing methods; (2) development of statistical statements concerning the data, and (3) the study of changes in material behavior, particularly radiation damage. These objectives impose differing demands on the curves, which result in several versions of each approach. The computational and mathematical procedures that can be used with the tanh function have been described in detail, with examples of the different curves that can be fitted to the data. Six different algorithms to be used for situations involving different constraints have been summarized. Weighted regression has been reviewed briefly, with emphasis on the use of models to describe the changes in variance between the different modes of material behavior.
Reproducibility of the Surface Area of Some Powders as Measured by the Monosorb® Surface-Area Analyzer Using the Brunauer-Emmett-Teller Equation
Authors: Ace HL , Parsons DS
Published: February 2009

The precision of the measurement of the specific surface area of powders was studied for 15 different materials. Measurements were obtained in such a way that both instrument and sampling contributions to the total errors could be estimated. The overall coefficient of variation was 6.5%. The instrument reproducibility was 2.7%. The total reproducibility of free-flowing powders was 4.2%, but for non-free-flowing powders, which are hard to sample, the total reproducibility was 8.5%.
A Statistical Analysis of X-ray Stress Measurement by the Gaussian Curve-Fitting Method
Authors: Kurita M
Published: February 2009

Simplified equations for calculating peak position and its standard deviation caused by counting statistics, which is a fundamental source of scatter in X-ray stress measurement, are derived for the Gaussian curve-fitting method. These equations when used with an inexpensive microcomputer will facilitate a precise and rapid residual stress determination. The time required for calculating the peak position and its standard deviation with such a microcomputer is only 0.9 s.

The residual stress in a hardened structural steel, Type JIS S45C, was measured. The standard deviation in the stress as measured by the Gaussian curve method was smaller than that by the parabola method, which until now has been the most widely used technique.

The variation in peak position in the Gaussian curve method with the various selections of data points used in the calculation is also smaller than that in the parabola method. Since the correction for background has little influence on the results, it can be omitted to reduce the measurement time.
A Constant Force System for Delayed Fracture Experiments
Authors: Wycherley GW , Henshall SG
Published: February 2009

A loading system has been developed to apply constant tensile forces to test pieces for delayed fracture investigations. The basic element of the system is a high compliance ring in which the test piece is loaded across the ring diameter after precompressing the ring in a universal testing machine. Details of ring compliance and forces achievable for rings cut from readily available pipes are given and simple techniques for monitoring the applied force are described. A reduction in cross-sectional area of 30 to 40%, consequent upon effective crack growth during testing, would result in about a 1% decrease in force for a ratio of compliances of ring to test piece of 5.5 to 1.
Simultaneous Determination of Shear and Young's Moduli in Composites
Authors: Fischer S , Roman I , Harel H , Marom G , Wagner HD
Published: February 2009

An experimental method is described to calculate both shear and Young's moduli of composite materials by three-point bending. The proposed procedure includes appropriate corrections for certain extraneous effects. The importance of the two basic ratios, E/G, which is an indicator of the degree of anisotropy of the material, and L/d, the span-to-depth ratio, is underlined.
Design of a Dynamic Gear Test Rig
Authors: Crawford RJ , Brown D
Published: February 2009

A test rig for plastic spur gears has been designed and built, based on the principle of an eddy current dynamometer. This offers considerable advantages over existing gear test rigs in that the torque level is infinitely variable and it can be adjusted if necessary during testing. A special noncontacting tooth breakage detector was also developed to stop the tests immediately if failure had occurred.

An extension to the basic test procedure is also described whereby real life loading situations can be easily simulated with a minicomputer coupled to the dynamometer.
Hydrogen Embrittlement of Zinc Coatings
Authors: Horvick EW
Published: February 2009

A brief review is given of hydrogen embrittlement of zinc-coated steel. Most of the steel that is hot dip galvanized is low carbon grade and, as such, little if any hydrogen embrittlement is incurred. Much of the steel that is electroplated is higher carbon grade and, thus, possibly subject to this problem. Methods of overcoming this are suggested. Most of the study on the subject has been with still plating; very little has been done with barrel plating.

An investigation on the effect of alkaline zinc electroplating on embrittlement of hardened parts under barrel plating conditions is reviewed. A pertinent consideration was the verification of previous observations that the use of zincate solutions reduce hydrogen embrittlement compared to those formulated with cyanide. Although many techniques have been used to measure the hydrogen embrittlement level, a simplified bend test with inherent advantages was used here.

A description of cathode surface preparation and embrittlement testing is discussed. Results are analyzed and interpretation of this is developed.
Multiaxial Fatigue: A Survey of the State of the Art
Authors: Garud YS
Published: February 2009

This paper surveys the current state of knowledge concerning multiaxial fatigue. Developments are presented in chronological order and are discussed so as to supplement existing reviews in this field. Emphasis is placed primarily on the criteria or methods of evaluation of fatigue strength under general multiaxial loading at room temperature. The survey indicates that the early development of the criteria was based on extensions of static yield theories to fatigue under combined stresses. These are stress-based criteria limited primarily to high-cycle fatigue. Most of the later criteria are strain-based. These criteria fall into two broad groups: the equivalent stress or strain type and the critical plane type. Most of these criteria commonly lack considerations of the cyclic stress-strain response. Their application to nonproportional loading suffers from difficulties in implementation or from inconsistencies with results of experiments. Recent approaches fall in the category of continuous damage evaluation methods. At present, these appear to be abstract or difficult to implement. All the above criteria are critically examined and compared. With this background, a new plastic work approach, proposed by the author, is discussed briefly.
Estimation of Cavitation Erosion with Incubation Periods and Material Properties
Authors: Veerabhadra Rao P , Martin CS , Syamala Rao BC , Lakshmana Rao NS
Published: February 2009

A detailed study of the normalized correlations between the incubation period tc and the properties of various materials tested in a rotating disk device indicates that, at very high intensities, the strength properties influence the duration of tc. The analysis of extensive data from other laboratories for cavitation and liquid impingement erosion also indicates that, while both energy and strength properties influence the duration of tc, the latter ones predominate for a majority of cases. A fatigue-type failure occurs during tc. For estimating the time required to pierce a metallic specimen in a rotating device a relationship tp = 160 tc0.44 is proposed. A detailed study of normalized correlations between erosion resistance (inverse of erosion rate) and tc values of different materials tested in the rotating disk shows that correlations are good. Analysis of data from eight other investigators clearly points out the validity and the usefulness of this type of prediction.
Sampling Plans with Low Consumers' Risk
Authors: Tye JB
Published: February 2009

When a low consumers' risk is required it can be controlled through the use of a sampling plan. This plan starts with the average outgoing quality limit and works through the limiting quality level to arrive at the sampling plan. Very large sample sizes are required.
Quality Control of Tests Conducted on Bituminous Mixtures in Quebec
Authors: Zaikoff P , Bouchard A , Langlois R
Published: February 2009

The quality assurance system of the Quebec Ministry of Transport uses laboratory test results to evaluate the quality of bituminous concretes. The success of the system depends to a large extent on the reliability of these results. To evaluate on a day-to-day basis the reliability of the results, the Ministry developed a method to control the quality of laboratory tests based on the precision and accuracy of the test method used (that is, interlaboratory control) and on the reliability of results obtained by each laboratory (that is, within-laboratory control). The application of such a method has permitted the Ministry to obtain and even increase the confidence that the quality assurance system will succeed. It has also allowed the Ministry to detect and correct certain weaknesses attributed either to the test methods or the laboratories.
Precision Strain Measurement at Elevated Temperatures Using a Capacitance Probe
Authors: Keusseyan RL , Li C-Y
Published: February 2009

A new type of capacitance displacement measuring system has been developed. The gage is directly attached to the specimen for measurements at elevated temperatures. This system has been successfully used in materials testing at temperatures up to 600°C with excellent repeatability and resolution in strain in the 10−6 range. Good temperature stability of the entire system is required to achieve the reported capabilities.
Characterization of the Crack Toughness Behavior of Structural Steels by the Tearing Modulus Parameter and Acoustic Emission
Authors: Khan MA , Shoji T , Takahashi H
Published: February 2009

The combination of elastic-plastic fracture mechanics and acoustic emission techniques is used for evaluating the fracture toughness behavior of structural steels. The results show that for certain situations the acoustic emission technique can be used to accurately estimate the J integral at a growing crack and therefore provide predictive information regarding failure in laboratory specimens of different geometries and sizes. The invariance of the normalized J resistance curve is demonstrated for the compact and bend configurations. A simple and realistic test method is proposed for the evaluation of a critical value of the J integral and the tearing modulus parameter in cases in which the scatter is of particular concern. Correlation between acoustic emission and the tearing modulus parameter is presented that permits an acoustic “rating” of the material. In addition, the significance of an extending ductile tear on the structural integrity in terms of tearing modulus and acoustic emission is discussed.
Acoustic Emission During Unloading of Elastically Stressed Magnesium Alloy
Authors: Lee SS , Williams JH
Published: February 2009

Acoustic emission (AE) has been recorded for a magnesium alloy that has been quasi-statically cycled elastically between zero load and tension. Delayed AE was observed during both loading and unloading, and the stress delay during unloading is further studied. An analytical expression is written for the AE unloading stress delay which is an elastic constitutive parameter. The potential use of these results for the acoustic emission monitoring of elastic stress states is discussed.
An Introduction to Some Precision and Accuracy of Measurement Problems
Authors: Grubbs FE
Published: February 2009

Errors of measurement and the imprecision and inaccuracy of instruments are defined with the aid of appropriate statistical analyses often required in such a treatment. Techniques are given for estimating and characterizing the parameters related to precision and accuracy of measurement. The concepts are highlighted with illustrative examples of the methodology, and useful precision and accuracy statements are advanced.
Effect of Weathering at Different Exposure Angles on the Tensile Impact Resistance of Thermoplastics
Authors: Yamasaki RS , Blaga A
Published: February 2009

The ability of a thermoplastic to serve as an exterior building component depends to a large extent on its impact strength and the retention of this property during service. A study was undertaken of the effect of the Canadian climate on the tensile impact strength (TIS) of eight clear and opaque commercial thermoplastic sheets exposed at different angles, and on the mechanism responsible for their loss of impact strength. The TIS of unexposed thermoplastics ranged from 98 kJ/m2 for poly(methyl methacrylate) (PMMA) to 1225 kJ/m2 for ultraviolet-stabilized polycarbonate, surface unprotected (PC). Following south/vertical (S/V) and horizontal (H) exposure the TIS of these thermoplastics was reduced from 20% S/V and 30% H for PMMA after five years to 65% S/V and 85% H for PC with a protective film after one year. For most of the thermoplastics tested, loss of TIS may be attributed to deterioration of ability to undergo plastic deformation, rendering the material more brittle.
Comparison of Aluminum Powder Average Particle Diameter Values Determined by Various Methods
Authors: Ping SW
Published: February 2009

Average particle diameters (APDs) from alloyed aluminum powders were obtained by three methods including these instruments: (1) Fisher Sub-Siever Sizer®, (2) Elzone Particle Counter®, and (3) the Microtrac. Although each method was relatively fast and gave consistent results, when compared against each other the differences observed were significant. These differences were caused by the instrumentation and mathematical expressions used in each technique. Generally, the Microtrac and Elzone volume mode APD results were similar for the −325 mesh powders and were approximately double the Fisher APDs for the −270+325 and −325 mesh air-atomized powders. Fisher APDs for spherical powders can be estimated by using the Elzone surface area mode APD values. The Elzone could detect much larger (up to 380-µm) particle diameters than the Microtrac (176 µm) or the Fisher (50 µm) and, therefore, analyzed more accurately the coarser powders. Scanning electron micrographs showed surface roughness and particle size distribution of the powders.
Tensile Properties of A357-T6 Aluminum Castings
Authors: McLellan DL
Published: February 2009

Consideration of high-strength aluminum alloy castings as primary aircraft structure requires assurance that these products will possess structural integrity. Current industrial design practices place factors on properties or loads to offset the unknown characteristics of castings in recognition that the only absolute guarantee of properties is achievable through destructive tests. This paper presents an evaluation of tensile properties and their relationships to physical parameters for A357-T6 castings as an attempt to improve product assurance through nondestructive inspections. By improving both production controls and the measurements of significant physical conditions, it is believed that adequate product assurance can be developed to make these materials competitive with various wrought aluminum alloy fabricated structures.
Latitudes of Viscosity Index Values
Authors: Baylé GG
Published: February 2009

An alternative and simple procedure for the evaluation of numerical precisions of viscosity index values is developed. The procedure extends the former mathematical treatment of Marmin and Sommelet, resulting in greatly simplified equations. The extended relations allow easy calculation of precision figures for the revised methods of viscosity index calculation in view of the adaptation to Celsius reference temperatures.
Influence of Cold Work on the In-Pile Stress Rupture Strength of 16Chromium-16Nickel-Niobium Austenitic Stainless Steels
Authors: Closs KD , Schaefer L
Published: February 2009

The in-pile stress rupture strength of three casts of 16Cr-16Ni-Nb stainless steel was investigated. Different pretreatments were used, namely solution annealing plus various cold-working levels up to 20%. Thermal stability under irradiation and the high-temperature embrittlement of the different material conditions were studied. The specimens were irradiated in the form of electrically heated pressurized tubes at irradiation temperatures ranging from 615 to 720°C. Irradiation time was up to 4800 h, corresponding to a maximum fast neutron fluence (E > 0.1 MeV) of 8.2 × 1025 n/m2.

Neutron irradiation caused a marked reduction in stress rupture strength for the solution-annealed and the cold-worked specimens. For the solution-annealed tubes, this reduction was mainly attributed to high-temperature embrittlement; the decrease in rupture strain was less pronounced for the cold-worked tubes. The reduction in stress rupture strength came mainly from an increase in creep rate. As far as stress rupture strength and creep strength at high irradiation temperatures were concerned, the 15% cold-worked 16Cr-16Ni-Nb steel was superior to the other cold-work levels.
Precision Secondary Resistors
Authors: Starr CD , Graule RS
Published: February 2009

Data on the stability of resistance of four types of secondary standards containing either Manganin® (a copper-manganese-nickel alloy) or nickel-chromium-aluminum-copper resistance wire have been measured for 19 secondary standards. The standards range from 0.01 to 1000 ohms and have been tested annually for about 7 to 14 years, although one standard has been in use and tested for 33 years. The change in resistance in parts per million is documented, and causes for the change are suggested. For the most part, the stability of resistance of the precision secondary standards is much less than the manufactured tolerance of ± 30 ppm/year.
Phase Analysis of Standard and Molybdenum-Modified Mar-M509 Superalloys
Authors: Bišs V
Published: February 2009

Phase characterization studies have been conducted by an ASTM Task Group on interlaboratory specimens of three Mar-M509-type superalloys heat treated to simulate service conditions. The results of the studies, employing X-ray and electron diffraction analysis and energy dispersive X-ray analysis, showed that the alloys contain (a) script-type metal-carbon (MC) carbides, (b) two types of eutectics (both containing M23C6-type carbides), (c) M23C6 carbides precipitated in the vicinity of script-type MC carbides and M23C6 eutectics, and (d) very fine MC carbides precipitated along crystallographic planes of the matrix phase. The molybdenum-modified Alloys XC-224 and XC-224Fe also contain M6C carbides. The compositional and crystallographic data for the phases are presented and discussed.
Gypsum Content of Cements Used in Concrete Cured by Accelerated Methods
Authors: Al-Rawi RS
Published: February 2009

The effects of the gypsum content of cement on several engineering properties of concrete cured by accelerated and normal methods were investigated. It is shown that increased gypsum content results in a significant decrease in the slump of concrete and that there is an optimum gypsum content, considerably higher for accelerated-cured concrete than for normally cured concrete, at which maximum strength is obtained.

Contrary to prevailing theory, the increase in the compressive strength of accelerated-cured concrete with increased gypsum content is too small to warrant a gypsum content higher than that for normal curing conditions. In addition, insufficient SO3 content cannot be the only cause for the reduction in the later-age strength of accelerated-cured concrete compared with that of normally cured concrete. The optimum gypsum content under accelerated curing conditions may be used without risk of reduction in the durability of concrete caused by excessive, delayed expansion.
Verification of Compliance Corrections Used in Determining Load-Line Energies from Dynamic Load-Time Data
Authors: McConnell P
Published: February 2009

Absorbed energy is readily determined by integrating the load versus load-line displacement function. However, in dynamic testing (strain rate approximately 10/s), load-time data are more conveniently obtained. Conversion of load-time data to the energy absorbed by a test specimen during an instrumented impact test requires that the energy absorbed by the test machine be deleted from the total energy represented by the area under the load-time curve. A technique is described whereby previously reported compliance corrections have been experimentally verified. A test specimen is allowed to deflect to an accurately known value. Integration of the quasi-load-deflection curve yields the energy absorbed by the specimen. This value is shown to compare favorably with that obtained from the compliance-corrected load-time curve.