bluuebunny/crossref_metadata_2025 huggingface dataset:
Air, Soil, and Sea Galvanic Corrosion Investigation at Panama Canal Zone
Authors: Pelensky M. A. , Jaworski J. J. , Gallaccio A.
Published: September 2009

Various combinations of metals are used widely in military and industrial equipment. Many of these are deployed worldwide and in many situations under aggressive natural environmental conditions. The object of this study and this paper relates to the effects of subtropical environment on coupled, dissimilar structural metals of military interest. These include aluminum, brass, magnesium, Monel, steel, stainless steel, and titanium alloys. The environments are the atmosphere at Fort Sherman, soil (burial) at Fort Sherman, and seawater (total immersion) at Coco Solo, Panama Canal Zone. Results of this study should have significance in the selection of materials for design of equipment for use in these environments. The atmospheric specimens are rectangular, directly coupled, and offsetted. Offsetting was employed since this would lead to variability in galvanic effects over the exposed surfaces and edges. End grain attack, particularly at the edges of the tempered and aged light alloys, is of interest. For soil burial and seawater immersion, cylindrical specimens connected through a polyacrylate resin cylinder were used. These were selected as suitable and convenient for this purpose.

The atmospheric specimens were placed at site in April 1973, and the soil and seawater specimens were located during Oct. 1973. Atmospheric tests are expected to continue for a total period of four years and soil, five years; seawater tests are likely to continue for a total of three and one half years.

Atmospheric, soil, and seawater specimens are returned to the laboratory periodically during the test for examination and weight loss determination to assess the effects of each of the environments on the various galvanic couple combinations.

Only limited results are available at this early stage of the investigation. Accordingly, no final determination can be made at this time of the significance of results.
Localized Corrosion Attack on Carbon Steel—Case Histories of Service Failures
Authors: Suss H.
Published: September 2009

Four case histories of service failures attributable to some form of localized corrosion attack are reviewed. The initial case history covers a problem that developed because of the failure to follow operational procedures and because the wrong chemical was used for the inhibitor. The second case history covers an instance where the conjoint actions of the environment and cyclic loading (fatigue) promoted accelerated localized pitting attack rather than the usual loss in fatigue strength generally associated with corrosion fatigue. The third case history presents the potential concerns in using an improperly controlled corrosion protection system. The final case history reveals the perils of allowing systems to remain partially filled with stagnant solutions.

A major concern is the possibility that the same type of failures will recur. An approach for possible actions in programs for the prevention of premature corrosion failures is recommended.
Pitting Caused by Chlorides or Sulfates in Organic Media
Authors: Mansfeld F.
Published: September 2009

The pitting behavior of titanium and titanium alloys, pure nickel, aluminum 6061, and stainless steel Type 304 has been studied using electrochemical techniques in methanol in the presence of sulfates or chlorides. An important factor is the water content of these solutions. In anhydrous solutions of methanol and hydrochloric acid (HCl), passivation cannot occur for titanium and high corrosion rates are observed. Addition of water at a concentration as low as 0.6 percent leads to passivation. The passive region is limited to noble potentials by the pitting potential which, up to 2.5 percent water, increases linearly with water content and is more or less independent of water content for higher concentrations. Similar observations are made for methanol containing sulfuric acid (H2SO4). Aluminum 6061 suffers from severe pitting when polarized anodically in methanol with 0.1 or 1.0 N H2SO4. Pitting was observed also for nickel after anodic polarization experiments in 2 N H2SO4 in methyl alcohol (CH3OH). Iron, on the other hand, could not be passivated and pitting, therefore, did not occur. Pitting occurred for stainless steel Type 304 in 0.1 N H2SO4 in CH3OH at rather noble potentials in the transpassive region. These results indicate that the solvent can have a large influence on the pitting susceptibility of metals. Titanium is very resistant in aqueous media, but shows pitting behavior similar to aluminum in organic media. It is also found that sulfates which do not cause pitting in aqueous media, where they even might be used as inhibitors, cause severe pitting in organic media for certain materials. Perchlorates have also been found to induce pitting in methanol. Phosphates lead to passivation by formation of a film of high electronic resistance. While pitting occurs on titanium in methanol containing 0.1 N H2SO4, no localized attack was observed under the same conditions in ethanol, ethylene glycol, or isopropanol.
Interpretation of Pitting Corrosion Data from Statistical Prediction Interval Calculations
Authors: Crews D. L.
Published: September 2009

The National Bureau of Standards data for pitting corrosion of ductile iron and steel pipe in four soils and gray cast iron and 3-in. Bessemer steel pipe in one soil have been treated by statistical methods to obtain the prediction intervals of estimated pit depths as a function of time. In the nonaggressive soils which are representative of most pipe installations, these ductile iron and gray iron pipe exhibited less corrosion than the companion steel pipe.

Prediction interval calculations are useful for quantitative analysis of corrosion data which has considerable inherent scatter and where service life is determined by the failure at relatively few points.
Solution Chemistry of Pitting of Iron in Artificial Seawater
Authors: Petersen C. W.
Published: September 2009

The mechanism of pitting corrosion in carbon steel in a simulated seawater environment was studied by obtaining data on the chemical changes which occur with time in the pit and cathode solutions. Quantitative measurements were made of pH; sodium, magnesium, calcium, iron, chlorine, sulfate concentrations, and weight loss. The solutions used in the analysis were generated by using a recently developed artificial pit which not only provided a sufficient amount of solution but also made it possible to obtain specimens from specific locations in the cell itself. The results show a depletion of magnesium, calcium, chlorine, and sulfate in the cathode region while sodium and hydroxyl ion concentrations increased. Inside the pit the chlorine, iron, and hydrogen ion concentrations rose while the calcium, magnesium, and sodium concentrations dropped. Based on the results of these tests, it is shown that the decrease in pH in the pit is greatly enhanced by the magnesium and calcium reactions occurring at the cathode and by the formation of iron colloids (Fe(OH)4− and Fe(OH)2+).
Use of Rapid-Scan Potentiodynamic Techniques to Evaluate Pitting and Crevice Corrosion Resistance of Iron-Chromium-Nickel Alloys
Authors: Morris P. E.
Published: September 2009

Rapid-scan potentiodynamic polarization techniques were utilized to determine pitting potentials (Ep) for Types 304 and 316 stainless steel in 25°C, 4 percent sodium chloride. Decreasing the test time by increasing the potential scan rate prevented the development of crevice attack, thereby permitting Ep to be measured accurately and reproducibly. A close examination of the rapid-scan polarization curve for Type 304 stainless steel in the potential region above Ep revealed two distinct linear segments. Static potential test results indicated that the more active linear segment was a response due to pitting attack, and the more noble linear segment was a response due to crevice attack. These observations suggest that if a rapid-scan potentiodynamic technique is employed, then pitting and crevice corrosion resistance might be measured by a single test procedure. In addition to the effect of potential scan rate, it was found that the test electrode surface finish is an important consideration in the determination of pitting resistance or crevice resistance or both.
The Influence of Temperature on the Elastic Constants of Some Commercial Steels
Authors: Garofalo F. , Malenock P. R. , Smith G. V.
Published: September 2009

Elastic moduli in tension and in shear have been determined at various temperatures between 75 and 1500 F for 21 different commercial steels, both carbon and alloyed.

With increasing temperature both the tensile and shear moduli decrease approximately linearly until a certain temperature is reached beyond which a more rapid decrease is observed; this temperature is 700, 900, and 1300 F for carbon, alloyed ferritic, and austenitic stainless steels, respectively. Poisson's ratio does not change significantly with temperature.

Very good agreement is found between the data obtained in this investigation and results, determined both statically and dynamically, that have been reported by various other investigators.
Methods for Determining the Elastic Constants of Nonmetallic Materials
Authors: Kuenzi E. W.
Published: September 2009

Test methods are described for determining the elastic properties of wood, plywood, glass-fabric laminates, and a variety of sandwich core materials. The experimental procedures were developed over a period of years and are used extensively at the Forest Products Laboratory in connection with research on these materials. Methods representing practice that is regarded as the best at present are described in detail where necessary. Alternative methods and their disadvantages are discussed briefly.
A Mid-Century of Metallography-Retrospect and Aspect
Authors: Wyman L. L.
Published: September 2009

This introductory presentation is devoted primarily to the “how and why” of ASTM Committee E-4 organization, and the impelling reasons for its material expansion of activities into many spheres of effort that now are a part of modern metallography. Committee E-4 began as a committee on microscope magnifications; then, as other means of structure analysis became available, it has always been in the forefront to establish organized effort to develop these methods. This has not only led to the expansion of subcommittee activities within E-4, but even more importantly, has instigated the formation of other technical committees of the Society such as E-7 on Nondestructive Testing and the Joint Committee on Powder Diffraction Standards which sponsors the Standard X-ray Diffraction Index which is recognized world-wide. The inherent concern of E-4 in microstructure is still manifest in its Photomi-crographic Exhibit each “show-year,” and which is of outstanding excellence because of the basic requirement that entries be instructive, rather than merely “attractive.” An early appreciation of the potentialities of electron micrography caused E-4 to initiate organized effort in this field, not only making outstanding contributions to the techniques and literature in this field through a series of STP's but which also led directly to the subsequently developed spheres of activity in electron microprobe and ion emission microscopy. The inception of these various fields of effort herein mentioned, as well as several others, are directly correlated with the technical papers presented in this symposium.
Quantitative Microstructural Analysis
Authors: DeHoff R. T.
Published: September 2009

This paper is presented as a review, not of the literature, but of the techniques of quantitative microstructural analysis. It contains all of the important relationships which permit the estimation of the geometric properties of three-dimensional structures from measurements made upon both sections (reflection microscopy) and slices (transmission microscopy) taken through the structure. The emphasis is upon what geometric properties are accessible to quantitative determination and upon the nature of the assumptions that underlie their measurement. An appreciable part of the content is devoted to semiquantitative methods, that is, to the analysis of systems in which one or more simplifying geometric assumptions are permissible. The inclusion of a section on the statistics of microstructural analysis, which deals with methods for estimating the number of measurements required to obtain a given level of accuracy, makes this paper selfcontained.
Electron Microscopy Applied to a Unidirectionally Solidified Al-Al3Ni Eutectic Alloy
Authors: Tice W. K. , Lasko W. R. , Lemkey F. D.
Published: September 2009

Optical methods, replicas, and thin foils prepared by both ultramicrotomy and electropolishing techniques, as well as direct surface analysis by emission microscopy, were evaluated in order to characterize the interfacial crystallography and morphology of unidirectionally solidified Al-Al3Ni eutectic specimens. Replicas gave somewhat limited data due to the presence of subtle artifacts created during metallographic preparation, while emission microscopy gave considerably more topographical definition than that obtained by optical methods. Microtomed sections also proved to be of little value due to the plastic deformation induced by cutting. On the other hand, thin foils prepared by electropolishing methods clearly resolved the morphology of the dispersed Al3Ni phase and permitted direct determination of the interfacial plane, as well as the cristallographic orientation relationships between Al-Al3Ni. The A3Ni rods were found to be bounded by prismatic facets which were coincident with low index planes of aluminum lying in the ⟨110⟩ zone axis.
Evaluation of Specimen Preparation and the Use of Standards in Electron Probe Microanalysis
Authors: Yakowitz H.
Published: September 2009

The magnitude of systematic and statistical errors in electron probe microanalysis due to faulty specimen preparation is discussed theoretically and experimentally. It is shown that this error increases as the energy of the X-ray line being monitored decreases and also as the X-ray emergence angle decreases. Specific specimens are chosen to illustrate various preparation problems in metallurgy, petrography, and biology. Generalizing from these, certain useful instrumental adjuncts can be listed; these adjuncts tend to allow the effects of the specimen surface on the analysis to be controlled more rigorously. Several conductive coatings commonly used are evaluated in terms of electron and optical transparency, adherence, X-ray attenuation, and thermal and electrical conductivity. Finally, a brief survey of standards employed in electron probe microanalysis is made. Situations for which nonelemental standards are required are outlined. The choice of standards for various types of work is discussed.
Irradiation Tests of Several Steels for Reactor Pressure Vessels
Authors: Hasegawa M.
Published: September 2009

The first trial irradiation tests of pressure vessel steels scheduled by the Steel Irradiation Joint Committee of Japan (SIJC) were begun in 1963 and completed in 1967.

ASTM Specification A302 Grade B, modified A302B with nickel, HY-80, and several other domestic-made low-alloy high strength steels were selected. Specimens were prepared from heavy thick plates up to 250 mm thickness, and experimental plates up to 50 mm thickness, both of which contained weld zones. Specimens from ASTM Committee E-10 were adopted as a reference material.

Througout the test sequence, other objectives were to clarify the preliminary effects on irradiation of (a) steel melting processes, for example, vacuum degassing, basic oxygen (L-D) converter smelting, or aluminumnitride treating; (b) thickness of plates and microstructures as affected by heat treatment; (c) welding and stress relieving; and (d) specimen size.

All specimens were encapsulated in newly designed helium-tight aluminum sheaths. A fusible metal gap was used to control high-temperature irradiation, and to ensure uniformity of neutron flux a rotating retractable rig device was adopted. The irradiation tests were carried out in the BR-2 reactor of the Centre d'#x00E9;tude de l'#x00E9;nergie Nucléaire (CEN) in Belgium, and the postirradiation tests were carried out in the center's radiation laboratory. In almost all cases fast neutron fluxes ranged from 3 to 4 x 1019 n/cm2 (over 1 MeV), and irradiation temperatures were 75 and 260 C.

Postirradiation tests included tension, impact, hardness, and microstructure examinations, but evaluation of the results were based mainly on the transition curves derived from standard Charpy impact tests. Significant results were as follows: (1) The effects of smelting practice are noticeable; the L-D process and the aluminum-nitride treatment, in particular, show good effects on the reduction of irradiation sensitivity. (2) The irradiation sensitivity of thick plates is largely influenced by thickness, that is, mass effect—and heat treatment. (3) In general, weld zones are somewhat more sensitive than the parent metal. (4) The shift of transition temperature (ATr) of the ASTM reference steel falls into the range of the trend band established by studies in the United States, but most specimens show much less sensitivity than the reference steel as measured by ATr except for long-time heated experimental specimens.
Development of Fuel Cladding for Fast Reactors
Authors: Cunningham G. W.
Published: September 2009

The U. S. Atomic Energy Commission is conducting an extensive program directed toward the development of thin-wall small diameter tubing that can remain in the fast reactor environment for periods up to three years at temperatures to 800 C, strains to 3 percent, and a total fluence of 3 × 10 23 nvt. Austenitic stainless steels have been selected as the reference material with vanadium alloys as the primary backup material. Emphasis has been placed upon quality assurance for commercially produced stainless tubing. The experimental program also includes extensive work on sodium corrosion and radiation damage.
Neutron Dosimetry for Fast-Reactor Irradiation and Surveillance Testing
Authors: Yoshikawa H. H. , McElroy W. N.
Published: September 2009

Dosimetry for fast-reactor irradiation experiments introduces problems not encountered in thermal reactors. The difference in neutron spectrum causes quite different responses among candidate dosimetry materials. Moreover, the damage modes in fast-reactor irradiations and in thermal reactor irradiations may be quite different. This work is aimed at developing adequate methods for spectral determinations, neutron dosimetry, and damage correlation for fast-reactor tests.

Spectral determinations have been performed using a multiple foil activation technique (SAND-II). The SAND-II analysis provides integral neutron flux data with an absolute accuracy of 10 to 30 percent. Intercomparison of analytical results, neutron spectrometer results, and SAND-II determinations indicate reasonable agreement among all three techniques.

While the SAND-II technique provides fluence data, threshold and resonance monitors are simpler to use. A slight modification of monitoring procedures used in thermal reactors suffices for fast-reactor dosimetry. Results from activation monitors in EBR-II and ECEL indicate the feasibility of the monitoring methods.

Damage correlation techniques depend on the mechanisms causing damage. Two of the mechanisms causing property changes during fast-reactor irradiations are displacement production and helium generation by neutron reactions. The fluence dependence for these mechanisms illustrate the need for correlation analyses.
Postirradiation Tensile Behavior of 300 Series Stainless Steels
Authors: Holmes J. J. , Robbins R. E. , Lovell A. J.
Published: September 2009

The effects of neutron irradiation on the tensile properties of several austenitic stainless steels are considered over a wide fluence and temperature range. At low fluence levels (about 1020 neutrons (n)/cm2, E > 1 MeV), displacement damage results in radiation hardening if the irradiation and test temperatures are below one half the absolute melting temperature (0.5 Tm) of the steel. Above 0.5 Tm, hardening no longer exists, but a ductility loss due to helium embrittlement is observed. The temperature above which radiation hardening is no longer significant increases with increasing fluence. Elevated temperature hardening after fast reactor irradiations is the result of void formation. The hardening observed after thermal reactor irradiations appears to be due to the formation of gas filled bubbles, but the nature of the gas is not clear.
Determining the Functional Life of Turbine Oils
Authors: Hall D A
Published: September 2009

The life of a turbine oil in a given application depends on such environmental factors as temperature, degree of agitation, presence of water, and active chemicals. The chemical composition of the oil is also very important.

The functional life of a new oil can be determined by comparing it with other oils of known performance in various long-term and short-term oxidation tests, and by inhibitor content. The functional life of a used oil from a turbine system can be determined by comparing its performance in these same tests with the performance of the same oil when new. The same tests are also useful in setting lot acceptance limits for evaluating incoming shipments of oil. However, in this case, the testing will have to be confined to the short-term variety.

Four tests for determining functional life of turbine oil are described and their usefulness discussed.
Synthetic prostheses, silicone, teflon, and etheron, with laboratory and clinical studies, including full jaw substitutions
Authors: Brown J. B. , Fryer M. P. , Ohlwiler O. , Kollias P. , Templeton J. B.
Published: September 2009

Since our earlier report in the Annals of Surgery in September 1960 on laboratory and clinical study of dimethyl silozane (Silicone) and halogenated carbon (Teflon), continued study and work has been carried on with these materials and with diisocynate polyether (Etheron). Because of numerous inquiries from individuals and from surgical services as to the present state of decision and of acceptance of these materials, it is thought that this report is indicated.
Principles of Polymer Implant Applications
Authors: Stone W. , Yasuda H. , Seiderman M. , Ore S.
Published: September 2009

Metals and plastics as functioning replacements are becoming an important and interesting development in modern surgery. Attempts to substitute chemically inert materials for defective organs or parts of organs were made in early medical history, but only in the past 20 years have these efforts met with any consistent success. It is interesting that eye surgeons were among the first in this field, although the size and delicacy of the usable structures in the eye would seem inconsistent with such work.

An important basic problem in the development of implants is the retention in tissues of the “incompletely covered foreign body.” This was first described and studied (for the past 15 years) in eye tissues. The concept of the incompletely covered foreign body has application in nearly every field of surgery.

Previously, it was believed that, for a would to heal, like epithelial cells must meet and join like cells. With the plastic artificial cornea it has now been shown that a wound can heal and create a barrier to bacteria and fluids with epithelial cells ending at a connective tissue barrier. The principles making possible the retention in tissues of the incompletely covered foreign body are discussed.

The utilization in tissues of the post-enucleation movable implant and plastic artificial cornea is described, and the uses of methyl methacrylate, silicones, Teflon, and hydrophilic polymers as related to the implantation of plastic artificial corneas, retinal detachment surgery, glaucoma drainage tubes, the repair of bony defects, replacing the vitreous of the eye, and substitution for the eye's crystalline lens are reported. Also mentioned are the problems which are encountered in implant material and fabrication.

The possibilities of the incompletely covered foreign body, especially in other branches of surgery, are pointed out.
Abstract Surface Properties and Wettability of Plastics
Authors: Zisman W. A.
Published: September 2009

Present knowledge of the ability of aqueous and nonaqueous liquids to spread and wet polymeric solid surfaces is reviewed and related to the surface energy of the solid and surface tension of the liquid. A discussion is then given of the effect on the wetting properties of addition agents dissolved either in the liquid phase or in the polymer. Since the relations of these properties and of surface roughness to adhesion are now well established, the subject of adhesion and adhesives for use in polymer implants can be treated with much more simplicity and confidence than had been possible in the past. The close relation of friction between solids and their adhesion is explained and then illustrated through a discussion of the effects of coatings and of addition agents on the frictional behavior of plastics.
Designing and Fabricating with Rigid Polymers
Authors: Pierson O. L.
Published: September 2009

A vocabulary of important properties of rigid polymers is presented and compared with some older materials such as metals, wood and glass. Those properties which affect the design of parts intended for long-term loading are discussed in detail. Application of data with the use of classic formulas from mechanics is illustrated.

Methods for fabricating prostheses from rigid polymers are summarized. Sheet plastics may be formed by heating to about 300 to 400 F. Commercial molding is usually not adaptable to making a few parts, but blocks of polymers are available for the machining of a variety of items. The materials may be worked by conventional wood or metal shop tools. Parts should be annealed and equilibrated prior to service to minimize dimensional changes due to environmental changes. Strong adhesives join plastics to themselves, but attachment to other materials requires careful attention. Autoclave sterilization distorts many polymers, but ethylene oxide appears safe with most, as are several solutions.

Examples are based on acrylic plastics, with which the author is most familiar, but the principles apply to most rigid polymers. Sources of additional detailed technical information are suggested.
The Effect of Texture and Strain Aging on Creep of Zircaloy-2
Authors: Fidleris V.
Published: September 2009

Creep tests were carried out on specimens machined from heavily cold-worked Zircaloy-2 sheet material in both the rolling (longitudinal) and thickness (short-transverse) directions. The texture of the sheet was such that the majority of grains had basal-plane normals oriented 30 deg from the sheet-normal direction, and was independent of the metallurgical condition. The creep tests were carried out in the range 100 to 350 C on both as-received (cold-worked) and annealed material.

The results varied with temperature and stress. At high stresses (all temperatures) such that rupture occurred in under 1000 h, the longitudinal specimens showed higher creep rates than the short-transverse specimens. However, at lower stresses the texture had very little effect on creep either in cold-worked material throughout the temperature range investigated, or in annealed materials between 250 and 310 C. In annealed materials tested at temperatures below 250 and above 310 C the longitudinal specimens had higher creep rates than the short-transverse ones.

The material exhibited strong dynamic strain aging which reached maximum intensity around 300 C. In some tests the creep came to a complete stop after about 1000 h. Activation energy for creep determinations showed little variations with texture, but a very marked peaking in the strain-aging temperature range.

Optical and electron microscope investigations of crept specimens revealed the formation of kink bands and a cell structure, especially in heavily deformed specimens, but little or no twinning.
Discussion on the Effects of Machine Straightening on Hydride Orientation of Zircaloy-4 Tubing
Authors: Shaheen L. C. , Rees T. W.
Published: September 2009

At the present time, Zircaloy-4 reactor-grade tubing is usually straightened using cross-roll pressure-flex machines of the Macintosh-Hemphill type.
Techniques for the Study of Precipitated Carbides
Authors: Forgeng W. D. , Lamont J. L.
Published: September 2009

The size, shape, distribution, and growth behavior of carbide particles have a pronounced influence upon the chemical and mechanical properties of low- and high-alloy steels. A relationship between the physical structure of the precipitated carbides and the corrosion susceptibility of 18 per cent chromium-8 per cent nickel steels has been clearly shown by Mahla and Nielson (1)2 and Kinzel (2). Crafts and Lamont (3, 4, 5) have shown how alloying elements modify the nature of the carbides and the properties of tempered and isothermally transformed steels.
Specimen Polishing Techniques for Electron Metallography of Steel
Authors: Grube W. L. , Rouze S. R.
Published: September 2009

Metallographic polishing techniques for electron microscopy are subject to stringent requirements as to quality. In order to use the extremely light etches required in electron metallography, it is essential that the surface be polished without relief effects and be free from distortion or flowed metal. The factors that must be considered in metallographic polishing are discussed, and the techniques that can be used to attain satisfactory polish are presented. A summary of the mechanical polishing methods used by members of Subcommittee XI, ASTM Committee E-4, on Electron Microstructure of Steel is also included.
Application of New Etchants for Delineation of Fine Structure in Steel
Authors: Austin A. E.
Published: September 2009

The application of electron microscopy to metallography requires the study of thin replicas of etched metal surfaces. The replica reproduces the contour of the metal surfaces, the contour variations being reproduced as thickness variations in the replica. The process of etching may introduce artifacts because of stains and undercutting. The formation of stains cannot be tolerated for they may adhere to the replica when it is stripped off or obscure the true structure if they do not strip off; etch undercutting will cause distortion in mechanically stripped replicas.
Positive Versus Negative Plastic Replicas
Authors: Schwartz C. M.
Published: September 2009

The shadowed negative plastic replica technique has, unquestionably, many of the characteristics required for the examination of a wide variety of microstructures. It is rapid, reproducible, and readily interpreted; the electron microstructures can be correlated well with those from light microscopy. The negative replica suffers, however, in two respects: (1) it is an inverse representation of the original specimen surface contour, and (2) the metal deposit, used to enhance contrast and resolution, highlights those areas of the replica which correspond to pits and valleys of the original surface. Neither of these objections are of significance when using the negative replica for survey work or for study of gross microstructure, if certain precautions are observed in applying the technique.
Time Effects in the Consolidation of Clays
Authors: Leonards G. A. , Ramiah B. K.
Published: September 2009

As pointed out by McDonald and Skempton (1),3 the phenomenon of consolidation in clays has been understood qualitatively for a long time. Around 1810 Telford preloaded the 55-ft bed of soft clay on which the eastern sea-lock of the Caledonian canal was to be founded, by building an embankment and allowing it to settle “for the purpose of squeezing out the water and consolidating the clay,” before constructing the lock (2). According to the writings of Sooy Smith (3), engineers in Chicago realized before the turn of the 20th century that the settlements of their tall buildings were due to the consolidation of clay beneath the foundations. However, it was not until 1923 that a quantitative approach first became possible, as a result of the publication of Terzaghi's one-dimensional consolidation equation (4). In connection with the development of his theory, Terzaghi (5) designed an apparatus for measuring the consolidation of clay (called an oedometer) which, in its essential features, is paralleled by the modern one-dimensional consolidometer. While the effects of remolding on the properties of clays were recognized before 1916 (6),4 and while Terzaghi was fully cognizant of the need for obtaining undisturbed samples before 1927 (7,8), the significance of this phenomenon was not fully realized until 1932, when Casagrande published his classic paper on the structure of clay (9). Although settlement estimates of structures were being made sporadically in the late 1920's (10,11,12 13,14),5 it was not until 1933, when the ASCE Committee on Earths and Foundations published its report giving descriptions of calculation procedures (15), that settlement analyses for structures on clay based on (a) the Boussinesq stress distribution theory, (b) the Terzaghi theory of consolidation, and (c) oedometer tests on undisturbed samples may be said to have entered the field of engineering practice (1).
Ohio Adopts the One-Point Mechanical Method for Determining the Liquid Limit of Soils
Authors: Joslin J. G. , Davis H. D.
Published: September 2009

The Ohio State Highway Testing Laboratory has been making soil tests for the past 25 years, starting with a modest 117 samples in 1934 to 32,202 samples in 1958. For the first 21 years the hand method for determining the liquid limit was used; an experienced operator could perform 60 to 70 liquid and plastic limit tests in an 8-hr day. The drawback to the hand method was that a new operator needed a training period of as much as a week and even then some never became proficient. Also experienced operators had to test known samples periodically in order to check their ability.
Liquid Limit Results from Various Types of Grooving Tools
Authors: Mitchell James E.
Published: September 2009

Early in the development of soil mechanics, a need arose for a system for classifying soils according to their physical characteristics. To meet such a need, Atterberg, in 1911, established upper and lower limits of plasticity for soils and developed test procedures to determine those values. For the upper limit, Atterberg selected a soil-water mixture which had very little strength and flowed like a liquid; hence his designation “liquid limit.” His test was designed to measure the water content at which a soil-water mixture would flow together in a groove of specified dimensions under a specific number of applied impacts. The lower limit of plasticity, which he called the “plastic limit,” denotes the water content at which a soil-water mixture ceases to be plastic and crumbles or breaks when rolled out into threads. The numerical difference between the liquid and plastic limit values, called the “plasticity index,” was found by Atterberg to be a satisfactory measure of the degree of plasticity of a soil. Because of their simplicity and ease of performance, the Atterberg limits tests have become a valuable and widely used aid for quickly predicting soil behavior.
Moisture and Strength Variation in a Thick, Uniform Clay Layer
Authors: Weber William G. , Kleiman William F.
Published: September 2009

The variation of moisture content, both horizontally and vertically, in individual specimens and in separate layers of a clay mass 105-ft thick is presented. Two hundred and thirty-eight soil specimens 2 in. in diameter by 4 in. high were tested in the laboratory. Four moisture determinations, two in the top half and two in the bottom half, were made on each soil specimen for a total of 952 moisture determinations. The moisture was of primary concern in this investigation, but as the samples were available, numerous other tests, such as grading analysis, Atterberg limits, triaxial and unconfined compression, were made. It is shown how much the moisture content does vary within a 4-in. high sample. There is no significant migration of moisture from bottom to top of sample during the time elapsed between sampling in the field and testing in the laboratory. The moisture content is higher in the bottom half just as often as it is higher in the top half of the 4-in. high test specimen. The shearing strength of the clay soil was determined by unconfined compression and quick undrained triaxial compression tests.

It is shown that the range of moisture content in a test specimen is much greater in the vertical direction than in the horizontal direction. There is no significant difference in the average strength-versus-moisture pattern, whether the moisture is the average of the strength test specimen or the highest of four moisture determinations made on the specimen.
Effect of Temperature on Moisture Contents as Determined by Centrifuge and Tension Techniques
Authors: Prill R. C. , Johnson A. I.
Published: September 2009

As a part of a program of cooperative research between the U. S. Geological Survey and the California Department of Water Resources, the amount and rate of soil-water drainage were studied in detail by the centrifuge moisture-equivalent and soil-moisture tension methods. One phase of this study was to determine the effect of temperature on the moisture content as determined by these two methods.

The effect of increasing temperature on the centrifuge moisture content and moisture content at a tension of ⅓ atmos was a small but significant decrease in moisture retained. Results obtained in the centrifuge studies indicated that reproducible centrifuge moisture content may be obtained with the control of temperature and humidity. The nonreproducibility of centrifuge moisture contents, a cause of criticism for this test for a number of years, may be attributed to the testing of duplicate samples at different temperatures.
Stress Distribution in Single-Shear Sheet Specimens
Authors: Yen C. S.
Published: September 2009

The state and distribution of stress in single-shear, double-notch sheet specimens were analyzed by the photoelastic technique. It was found that the shearing stress in the central area was neither pure nor uniform. Because of the stress state and distribution, it cannot be used to determine creep or stress-strain relations in pure shear. However, it is possible that it may be used to determine the ultimate shearing strength in materials of sufficient ductility.
On the Lap Joint Shear Test for Metal-to-Metal Bonds
Authors: Shane R. S.
Published: September 2009

This paper suggests modifications of ASTM Method D 1002 – 53 T which is currently being revised. During studies on the preparation of aluminum, stainless steel, and magnesium surfaces for adhesive bonding, certain modifications were made in this lap joint shear test. These modifications resulted in a much smaller than usual standard deviation in the test results, about 5 per cent of the mean value. The modifications in the test included: (a) uniform rate of application of stress, (b) improved grips, (c) making specimens in a jig to assure parallelism of lap components, and (d) cutting steel specimens with an abrasive wheel.

Data are presented on: (1) choice of a test adhesive, (2) effect of parallelism of press platens, (3) uniformity of heating of press platens, and (4) effect of location of test specimen within a panel. The method used to prepare the metal surfaces is described elsewhere.
Shear and Torsion Testing of Solid Materials—A Critical Discussion
Authors: Clapper R. B.
Published: September 2009

This discussion includes a critical review of papers presented at the Symposium on Shear and Torsion Testing. Work presented elsewhere on this subject is summarized and critically compared, and testing variables and problems for investigation are discussed. It was found that the plastics, rubber, and forest products industries have well-planned and time-tested standard practices. Although the metals and the ceramic industries have numerous methods of evaluating shear strength, very little has been accomplished toward standardization of test methods for these materials.

This review is designed to assist Subcommittee 25 on Shear and Torsion Tests of Committee E-1 on Methods of Testing in preparing new standard methods of testing in shear and torsion, and for recommending revisions to current standards.
The Hose-Stream Test as a Part of Fire-Testing Procedure
Authors: Ingberg S H
Published: September 2009

The basis for the inclusion of the hose-stream test as a part of fire-testing procedures is presented and the part it plays in the acceptance or rejection of the constructions tested. The force of the stream, as determined by computation and tests, is below the levels serving as a test for the stability such as of walls and partitions. The paper should be helpful in determining the extent to which the hose-stream test is justified as presently required in ASTM Methods E 119 and in considering any further changes relating thereto that should be made in the standard.
Effect of Restraint on Fire Resistance of Prestressed Concrete
Authors: Selvaggio S L , Carlson C C
Published: September 2009

When fire occurs in a building, the structural parts tend to expand under the effects of the resulting heating. Thermal expansion of structural building components may be variously restricted according to the resistance offered at the supports or by the stiffness of abutting constructions. Restriction of thermal expansion has been shown by many fire tests and by evidence from building fires to have an important influence on the structural behavior of building elements during exposure to fire.

Described in this paper are results and impressions gained in an exploratory study of the effect of varying intensities of restraint of the thermal expansion of precast, prestressed concrete double-tee floor elements during the course of standard fire exposures. The principal variable in the study was the amount of linear expansion along the axis of the span allowed before further expansion was stopped. Relationships between given expansions, the resulting expansion forces, and midspan deflection are presented. The changes in the location of the center of thrust at the ends of the members during the course of the fire exposure are discussed. Further investigations on the subject of restraint are suggested.
Nondestructive Testing of High-Strength Steel Rocket Motor Cases
Authors: Hendron J. A.
Published: September 2009

Proportionately, the wall thickness of a hen's egg, compared to its outside diameter, is six times as great as the same comparative dimensions on one of the solid rocket motors currently in production. This fact proves nothing in terms of material strnegth, but it does serve to illustrate the degree of structural perfection demanded in high-strength steel rocket motor cases.
The Radiolytic Decomposition of Crystalline Alkali Metal and Alkaline Earth Bromates
Authors: Chase John W. , Boyd George E.
Published: September 2009

Yields for bromate ion decomposition and for the production of oxidizing fragments, bromide ion, and oxygen gas in the radiolysis of the crystalline alkali metal and alkaline earth bromates by cobalt-60 γ-rays, neutron reactor radiations, and lithium-6 fission recoil particles were determined as a function of dose, temperature, and dose rate. The oxidizing fragment yields were strongly temperature dependent. Thus, radiolysis at 300 C gave only bromide ion and oxygen gas; at lower temperatures increasing amounts of oxidizing fragments including hypobromite, bromite, and bromine species with higher oxidation numbers were formed. At large doses the oxidizing fragment concentrations tended to “steady-state” values dependent on the irradiation temperature. These values were determined as a balance between the rate of production of these fragments, their thermal decomposition to bromide ion and oxygen gas, and their recombination to bromate ion. The reaction of BrO−2 ion with oxygen atoms produced thermally or by γ-rays is proposed to account for the recombination and, hence, for the annealing of the chemical radiation damage. The yields of the radiolytic products were dependent upon the nature of the cation of the salt but were independent of the dose rate.
Activation and Sintering Behavior of Calcium Oxide—the Effect of Copper X-Irradiation on the Surface Area of the Oxide Produced by Thermal Decomposition
Authors: Mikhail RSh
Published: September 2009

The thermal decomposition of a parent material presents a common tool in the preparation of active solids, mainly oxides. In lime-burning practice several factors are now known to affect the activity of the produced oxide. Among these factors are the structure of the initial material, temperature and duration of calcination, and the presence or absence of air during decomposition.

The present investigation deals with a new factor which may appreciably affect the activity of the produced oxide, namely, the effect of copper x-irradiation.

Copper x-irradiation of the parent material did not cause any variation of the surface area of the starting material or its decomposition products. But the irradiation of the partially or the completely dehydrated products resulted in measurable changes of the surface area. These changes were traced for products heated under vacuum at different temperatures for fixed durations, and for products heated at constant temperatures for various durations.

For products heated for a fixed duration of heating at different temperatures, all specimens showed a tendency for loss of area upon irradiation. Both the irradiated and unirradiated specimens give an area-temperature of decomposition curve characterized by a maximum, but this maximum was more sharp and was shifted to lower temperatures in the case of the irradiated specimens. Irradiation seems to assist well in reducing high area solids and activating the process of sintering.

The effect of variation of duration of heating at a fixed temperature on the surface area showed measurably higher areas for the irradiated than unirradiated specimens for incompletely decomposed samples. As decomposition approached completion the effect was reversed and the irradiated products showed smaller areas than the corresponding unirradiated samples.

The results are discussed mainly to show the effect of irradiation on the different stages followed by a solid during thermal decomposition; these stages are dissociation, recrystallization, packing, and finally sintering, and a possible interpretation is presented.
Can the Service Life of Bonds Be Predicted?
Authors: Northcott P. L. , Colbeck H.G. M. , Kozak A.
Published: September 2009

The need for a method of predicting the service life of any glued product in a particular application from a few weeks or months of laboratory work is indicated. The problems of making such a prediction are briefly reviewed. The results of accelerated weathering tests are compared with the results of ten-year exposure tests of phenolic-bonded Douglas-fir plywood. Four strengths of phenolic bonds from stronger than the wood to weaker than the wood are included. It is shown how this information can be used to predict the service life of painted and unpainted plywood exposed to the weather. The prospect for extending the system to predict the service life of any glued product for any specified use is discussed.