bluuebunny/crossref_metadata_2025 huggingface dataset:
The Growing RôLe of Protective Coatings for Metals in High Temperature Service
Authors: Harrison W. N.
Published: August 2009

During the few hours required for conducting this Symposium, ceramic coatings were applied, at one plant in this country, to eight heat exchangers for large aircraft. This figure of one every 20 min. is based upon a reported production rate of 120 per week, on a one-shift schedule. In 1944 the regular production of steel exhaust stacks (S.A.E. 1025) with a high-temperature ceramic coating was begun, and there is still a regular schedule of production in these same items. In the meantime, tens of thousands of steel exhaust stacks have been coated, the production schedule naturally being at a peak during the war. These facts are important to the present discussion because they indicate that ceramic coatings are already effective in the high-temperature protection of metals in some phases of the aircraft industry, and we may therefore infer that they are promising as protective coatings for gas turbine materials.
Introduction
Authors: Harris J. C.
Published: August 2009

The literature on soaps and other detergents is replete with many methods for evaluation of these materials. Because the methods used frequently tend to measure either individual properties or to measure the results obtained through the combined properties of a material, it has been difficult to agree upon the methods for evaluation. ASTM Committee D-12 on Soaps and Other Detergents attempts to present to its members new techniques for evaluation and also to bring various proponents of specific methods together for a discussion of the problem. The March, 1951 meeting was notable for the variety and number of papers and discussions presented. Wherever possible, papers of a like nature were held under the auspices of the interested subcommittees. Others of general interest were presented at the general meeting which follows the annual business meeting. The following papers were presented at subcommittee meetings or were heard at the general meeting and are included in this compilation: Measurement of the Adsorption of Anion-Active Detergents by Materials Commonly Washed—W. A. Fessier. A Metal Cleaning Test Using Radioactive Stearic Acid as Soil—J. W. Hensley, H. A. Skinner, and H. R. Suter. Laboratory Performance Test for Detergents in Continuous Wool Scouring—F. A. Leonard. Practical Evaluation of Soiled Test Pieces— R. B. Mitchell. An In-Vivo Method for Determining the Degerming Efficiency of Soaps Containing Hexachlorophene—A. R. Cade. The Mechanism of the Wetting of Textiles— I. J. Gruntfest.
The Importance of Correlations in Detergency Testing
Authors: Lambert Joseph M. , Leshan Edward J.
Published: August 2009

About three years ago, attempts were made in our laboratory to apply statistical methods of correlation analysis to a series of comparative detergency tests. Some of this work was later published by Lambert and Sanders (10), but none of the results obtained by quantitative correlation analyses needed inclusion; this was fortunate, since the inadequacy of the existing statistical methods for determining the reality of an apparent relation between two testing methods has meanwhile become obvious. The difficulties are particularly serious if only six or eight detergents are used for providing the experimental data as in this case. Recently, Harris and Brown (7) published two papers whose main topic was the comparison of wash test methods and of soiled test fabrics. With the exception of one set of data in the second paper, only four detergents were used in the various tests; nevertheless, the correlation coefficients based on such sparse information were tested for significance and the tests ranked accordingly. As will be shown later, this type of treatment, making little allowance for the fact that the calculated coefficients are only very doubtful estimates of the true values, passes up truly high correlations and mistakes negligibly small correlations for important ones. There is no doubt that correlations should be studied extensively in detergency testing work. As one of the present authors has pointed out previously (9), the prime objective of laboratory procedures for the evaluation of detergents is to rank commercial or experimental products in accordance with their performance in practice. Therefore, it is apparent that the ultimate evaluation of the usefulness of a particular test method depends on a careful comparison of the results obtained with those available from end-use tests. Furthermore, in the development of improved laboratory methods, it is frequently of importance to determine the degree of concordance between various procedures. A case in point is a comparative study, which was made in our laboratory, testing ten detergents in an abridged multicycle test and in a single cycle test with an experimental soiled fabric. While preliminary results of the correlation analysis were given elsewhere (9), it was thought of interest to reinvestigate the available statistical methods more thoroughly and to determine just how much useful information could be extracted from the data. Before presenting the various steps of the statistical correlation analysis, it seems appropriate to discuss some of the simpler methods for studying correlation or lack of correlation qualitatively or semi-quantitatively. The usefulness of these latter methods will also be illustrated by a few examples taken from practice.
Electrical Resistivity of Bonded Micaceous Materials at Elevated Temperatures
Authors: Wechsler Kenneth
Published: August 2009

Electrical insulating plate made of inorganic bonded mica splittings has a long satisfactory history as heater conductor insulation in applications requiring relatively little mechanical support for the insulation. Nevertheless, standard test methods for determining the quality of this material are singularly lacking, as are specifications prescribing acceptable quality levels for the material as such. The insulating heater plate is required, among other things, to resist in end use the passage of current through its volume and across its surface while exposed to elevated operating temperatures. The relative deleterious effect of the surface and volume leakage currents is determined by the specific design of the appliance. Electrical volume and surface resistivities at the operating temperatures are, therefore, two of the various properties of heater plate that are functionally related to the end use. The purpose of this paper is to describe a test method for the determination of the volume and surface resistivities, measured at the extreme temperature normally associated with the use of inorganic bonded muscovite heater plate. The test method is intended to provide a convenient means of measurement suitable for use as an acceptance test and for manufacturing control, with the degree of accuracy and precision necessary to distinguish between quality levels of heater plate and to produce satisfactory agreement between various laboratories as to the quality levels.
Test Methods for Studying Thermal Stability and Heat Aging of Electrical Insulating Varnishes
Authors: Haroldson A. H.
Published: August 2009

The thermal stability of electrical insulating varnishes is usually tested by evaluating the effect of elevated temperatures on the physical and electrical properties of a varnish film. The varnish film is tested in the form of a coating on 0.005 in. thick, 1 1/2 in. wide copper foil or as a coating on cotton or glass cloth. Asbestos paper and mica mat have also been used as supporting media for testing insulating varnishes. Since electrical insulating varnishes are composed of one or more organic components, they are subject to deterioration at elevated temperatures. Deterioration is the result of chemical and physical changes occurring in the varnish film during the heat-aging period. The chemistry of heat aging is very complex because of the many possible reactions that can occur. It is possible, however, to correlate certain types of chemical reactions with changes in the physical and electrical properties of a varnish film. There is considerable difference in chemical composition between the various commercial insulating varnishes. Varnishes made of synthetic resins usually form more heat-resistant films than varnishes made of natural resins. The silicone varnishes possess unusually high heat resistance and are chemically very stable, particularly in their resistance to oxidation. When the variables in the varnishes themselves are considered, it is evident that heat-aging tests must be interpreted with caution. Accelerated heat-aging tests are conducted at higher temperatures and under conditions such as total exposure which are not encountered in actual practice. Therefore, too great a reliance should not be placed upon short-time tests alone, but they should be supplemented by long-time tests. Probably the most valuable knowledge obtained from accelerated heat aging tests is the information furnished the design engineers concerning the effect of continuous operation at elevated temperatures upon the varnished insulation and observation of the shortness of the resulting life.
Electrical Properties of Thermosetting Plastics at Elevated Temperatures
Authors: Winans R. R. , Hand W.
Published: August 2009

The development of special equipment and procedures for the study of electrical properties of thermosetting plastic materials at elevated temperatures are described in detail. Descriptions of equipment for elevated temperature measurements of dielectric strength, dielectric constant, electrical loss, and electrical resistance are presented. Data on the effects of long- and short-time exposures on several laminated materials are given. Emphasis is placed on very short-time temperature exposure in view of the extreme changes in properties exhibited by many materials. Changes in properties, both transient and permanent, are noted. Crazing of silicone laminate at elevated temperatures was detected and is described.
Inspection, Processing, and Manufacturing Control of Metals by Ultrasonic Methods
Authors: Hastings Carlton H. , Carter Seymour W.
Published: August 2009

In order to predict with some degree of certainty whether any test method can be adapted to a particular inspection problem or more fundamentally to develop methods which can be applied, the physical principles of methods must be understood as completely as possible. Only after such an understanding has been obtained can further exploitation and technical development along particular Unes be justified. The general inadequacy of available methods for the inspection of metals at war-time production rates was first indicated by experience during World War II. The realization of this situation came too late, however, to allow for revision of methods then used and the substitution of new ideas for inspection tests. In a few specialized cases, new methods were provided and adopted, but these methods were by no means fully exploited. A test method which aroused considerable interest during the war, utilizes energy in the form of high frequency vibrations (ultrasonic vibrations) for the detection of flaws in certain parts. Successful application of this method in specific cases indicated a much wider utilization of the principles employed therein. The report presented herewith is a summary of available technical literature through 1946 on the subject of ultrasonics as applied to metals. Particular emphasis has been placed on the detection of flaws or discontinuities in metals since the bulk of the literature encountered has dealt with this application. However, other metallurgical applications were encountered and have been included for the sake of completeness and to promote speculation along these lines.
Basic Principles of Practical Ultrasonic Testing
Authors: Smack John C.
Published: August 2009

Ultrasonic testing, now in its fifth year in practical use, has, during that time demonstrated its ability to economically test non-destructively many materials and industrial parts. In many cases it has saved thousands of dollars of wasted machine time and labor, increased production and reduced the hazard of accidents due to defective or over-stressed parts. It is not, however, the panacea for all inspection troubles. Like all methods of non-destructive testing it has its limitations. It is just as important to know what it cannot do as what it can do, because misapplication can sometimes be more harmful than no test at all. It is doubtful that ultrasonic testing will entirely supplant other testing methods such as X-ray or magnetic particle testing. Although they overlap in their application, each has a distinctive field. Frequently they supplement each other. Using ultrasonic testing it is now possible to explore areas inside of metal sections which could not previously be tested or inspected. To apply ultrasonic testing intelligently one should have a clear understanding of the basic principle of operation, the available equipment, the techniques of application and the best procedure to follow when setting up test standards. The knowledge of basic formulae may be desirable but is certainly not necessary. One should, however, have an understanding of how the ultrasonic vibrations are generated and projected through the materials and the reaction inside the same materials.
The Application of Ultrasonics to the Fabrication of Aluminum
Authors: Carroll J. V.
Published: August 2009

The non-destructive ultrasonic test for the determination of the internal soundness of aluminum ingots, forging stock, forgings, and large rolled shapes has been found to be rapid, economical, accurate, and readily adaptable to production methods. In some finish rolled sections of critical size, notably aircraft wing spar sections where a high degree of perfection is required, a final ultrasonic inspection is made. Ultrasonic testing has been found useful in the development of new ingot casting methods and new alloys. Various rolling mill operating practices have been more intelligently evaluated through the prior knowledge of the internal quality of the ingot or bloom as afforded by an ultrasonic inspection. Like some of the other non-destructive test methods, ultrasonic testing may lead to improper conclusions concerning the quality of the product, unless the results of the test are properly interpreted. As more varied and extensive use is made of this method with aluminum products, common nomenclature can be developed and agreement on the interpretation of the results should become possible.
Ultrasonics in the Electrical Industry
Authors: Kelman D. M.
Published: August 2009

Ultrasonic instruments are now firmly established as inspection tools in the electrical industry. At Westinghouse, in the role of a consumer, the instruments are used for the inspection of incoming raw materials. The company, under the classification of a producer, uses them for the inspection of finished and semifinished products. In this last classification, ultrasonics are used both for the inspection of materials, and for the control of processes. For these tests the two types of ultrasonic instruments previously described in this symposium are used, that is, the type of instrument using the principle of time of travel of the wave through the material being tested, and also the instrument using the principle of the resonant wave in the material. In the role as a consumer, a program of testing some of the largest steel forgings is underway with the idea of gathering as much information as possible about the general condition of these forgings so that the design engineers can more intelligently and with greater assurance apply their safety factors, thus permitting them to more fully utilize the inherent properties of the material, while at the same time making certain that no injurious conditions exist. This program, is being applied to all large turbo generator rotor forgings. These rotors vary in size from about 20 in. in diameter and 10 ft. in length to 50 in. or more in diameter and 30 ft. in length with some weighing over 150,000 lb. For these tests, the Supersonic Reflectoscope is used and the rotor is tested both longitudinally and diametrically as shown in Fig. 1. This photograph was taken at the beginning of the program and shows the test being applied to an almost completely machined rotor. At the present time the testing is done before machining except for a smooth over-all cut taken to provide a surface suitable for ultrasonic inspection.
Pulse Techniques Applied to Dynamic Testing
Authors: Leslie J. R.
Published: August 2009

Many of the difficulties inherent in present methods of dynamic testing can be overcome if pulse techniques are utilized. In this method the velocity of propagation of an acoustical pulse through the material is measured. The pulse velocity so obtained is unaffected by size or shape of the specimen, and the elastic modulus may be calculated using one simple formula for all cases. An electronic pulse test set developed primarily for testing concrete structures in the field is described. A pulse generator and receiver are used, applied to opposite faces of the structure. The time of travel of the pulse is measured on a cathode ray tube using a strobe circuit and direct reading dial. More than two years' experience in testing laboratory specimens, for which it is now in regular use, is described. Mass concrete in the field has been tested for both deterioration and cracking; in one case many thousand readings were taken. The instrument's application to the location of rot in wood pole specimens and to the testing of soils is also illustrated.
The Role of Thin Surface Films in the Deformation of Metal Monocrystals
Authors: Gilman John J.
Published: August 2009

The literature on the strengthening effects of surface films on metal monocrystals (termed the “Roscoe effect”) has been reviewed. Available data show that the effect cannot be explained in terms of the strength of the film itself; rather, an interaction between the film and the crystal surface must be involved. New data confirming this viewpoint are presented. X-ray diffraction measurements of the distortions at the surface of zinc crystals were made. The measurements showed that a copper film (∼1000 Å thick) caused a marked increase in the surface distortion that occurs when a crystal is pulled in tension. It is concluded that the Roscoe effect is caused by the inhibiting effect that a surface film has on the exit of slip from a crystal. The effect that a film might have on the generation of slip on the surface is not believed to be an important factor.
Effect of Strain on the Oxidation of Nickel-Chromium Heater Alloys
Authors: Gulbransen Earl A. , Andrew Kenneth F.
Published: August 2009

To give a more complete picture of the physical and chemical factors involved in high-temperature oxidation, a new test method was developed called “strain-oxidation.” In this test the metal is oxidized a given amount, strained 1 to 4 per cent, and then reoxidized. The rates of oxidation before and after strain are carefully measured. Five nickel-chromium heater alloys of varying silicon and manganese compositions are studied. Two kinds of damage in the oxide film are found as a result of strain. The first is shown by a rapid rate of oxidation on first reoxidizing the metal while the second involves a long-term effect. Results on the high-silicon alloys show that strain has only a minor effect on the rate of oxidation. The strain-oxidation tests show good correlation with the ASTM useful life tests and suggest that the resistance of the alloy to stress during oxidation is relatively more important than the rate of oxidation at a given temperature.
The Properties of Oxidation-Resistant Scales Formed on Molybdenum-Base Alloys at Elevated Temperatures
Authors: Gleiser M. , Larsen W. L. , Speiser R. , Spretnak J. W.
Published: August 2009

Due to the limitations of externally applied claddings for protecting molybdenum-base alloys from oxidation at elevated temperatures, a program of developing protective self-regenerative scales on molybdenum-base alloys was conducted. Various molybdates and molybdenum-containing oxide complexes were tested for stability at elevated temperatures in order to determine if they would be stable at operating temperatures and thus possibly present a barrier to further oxidation. Nickel and cobalt molybdates appeared promising and were further studied in terms of their properties and their ability to form protective scales upon molybdenum alloys containing them. Results of oxidation tests show that molybdate scales will form on molybdenum-nickel and molybdenum-cobalt alloys and are protective. Both nickel and cobalt molybdates spall upon thermal cycling. Spalling can be suppressed by the addition of certain third components which stabilize the molybdate crystal structure. The nature and suppression of spalling are discussed.
Oxidation at Elevated Temperatures
Authors: Radavich John F.
Published: August 2009

Corrosion investigations on ferritic stainless steels have shown that initial oxidation takes place by the formation of a thin oxide substrate on which nodules of oxide nucleate and grow (1). Extensivepreliminary work sponsored by the International Nickel Co. on high-temperature oxidation of austenitic alloys heated at 815 C showed that a similar growth phenomenon takes place on most of the common austenitic alloys but differs in the case of the complex high-temperature alloys N-155 and Hastelloy C (2). Under the sponsorship of the International Nickel Co. and under the direction of V. N. Krivobok and C. R. Mayne, a project was undertaken to study the initial oxidation of various high-temperature alloys, using electron microscopy, reflection electron diffraction, transmission electron diffraction, X-ray diffraction, and X-ray spectrography. Because the oxidation process can be studied for much longer times at the lower temperatures and in view of corrosion data obtained at 600 C, the majority of oxidation studies were carried out at this temperature; however, data of oxidation carried out at 815 C will also be included. This paper will describe the various techniques used in the course of the investigation and present the results of oxidation of seven high-temperature alloys. The experimental work will be divided into two sections. Section I will deal with a detailed study of the initial oxide growth on the alloys by means of electron microscopic examination of surface replicas and stripped oxide films. In this section, electron microscopic studies of the oxide growth occurring on one region after repeated oxidations will be presented for the N-155 and a typical iron-chromium-nickel alloy. Section II will deal with the analysis of the structures and the identification of the oxide films formed on the seven alloys.
The Influence of Rate of Loading on the Strength of Wood and Wood-Base Materials
Authors: Markwardt L. J. , Liska J. A.
Published: August 2009

That the strength properties of wood and wood-base materials are influenced by duration of stress has long been recognized, both in the use of design stresses and through the establishment of rate of loading requirements in standard test methods. This paper presents a summary of recent data that supplements the information presented by the authors at the 1948 ASTM symposium on the same subject (4). Extensive data have been obtained on the effect of rate of loading on the compression-parallel-to-grain and flexural strength properties of two hardwood and two softwood species. The similarity of trends obtained from short-time and long-time tests indicates that the relationship between ultimate strength and time can be presented in a simple curve from load durations of a fraction of a second to many years. Values for modulus of elasticity remain substantially constant irrespective of rate of loading. Data are also presented to show that the flexural strength of building fiberboards of the densities tested is increased as the rate of loading is increased. Further tests are necessary, however, to establish more precisely the magnitude of this effect for fiberboards. Additional studies are needed further to determine, for both wood and wood-base materials, the influence of rate of loading on other mechanical properties, and to provide more substantial data on the effect of loadings extended over many years.
Effect of Speed of Testing on the Tension Test of Elastomers and Hard Rubber
Authors: Scott D. C. , Villars D. S.
Published: August 2009

This paper presents a review of the investigations involving the effect of speed of testing on the tension test of elastomers and hard rubber. It is concluded that, for elastomers in the range of 20 in. per min. or 0.03 per cent per millisecond, the elongation rate usually has little effect. At speeds above 4 per cent per millisecond, however, the test results are altered. For elastomer stocks which crystallize, tensile strength is independent of speed until rates too fast for crystallization to occur are exceeded after which point there is a drop in tensile strength. Above elongation rates of about 10 per cent per millisecond, tensile strength increases as slipping contacts have less chance to relax. For hard rubber, increasing speed seems to increase tensile strength even at low speeds.
Notes on Effect of Speed of Testing on Tensile Strength and Elongation of Paper
Authors: Green Ralph E.
Published: August 2009

Tensile strength and elongation of paper are affected by (1) specimen length, (2) specimen width, (3) edge effects, (4) temperature and humidity, and (5) speed of testing. This paper deals with the effect of speed of testing only. The kinds of paper included in the present test program, Table I, were chosen because they are subjected to tensile forces at various speeds of application during their periods of usefulness. In these five papers, tensile strength and elongation are important factors in predicting performance. All tests were performed on a Thwing-Albert Model 49RC Electro-Hydraulic Tensile Strength Tester. Specimens were cut individually on a precision sample cutter 1 in. wide. Specimen length was 8 in. between grips. Jaw surfaces were 1.25 in. wide by 1 in. deep; the stationary jaw was smooth and the other serrated. Traverse time of recorder pen for full scale deflection to balance was 2.4 sec. Table II lists average tensile strengths of 10 specimens at operating speeds of 0.1, 0.2, 0.5, 1.0 and 2.0 in. per min in both machine and cross-machine directions.
Introductory Remarks
Authors: Pinner W. L.
Published: August 2009

Committee B-8 proudly sponsors this symposium with the thought that the papers will be of great value to engineers and others concerned with materials, processes, and tests involved in the use of electrodeposited metallic coatings. The particular subjects presented are representative of the type of activity with which Committee B-8 is concerned, although they do not cover all subjects on which committee work has been carried out. An all-inclusive presentation would require several days. Thus, Spring's paper on metal cleaning, for example, is important but otherwise typifies standard-practice treatments which have been published on diverse subjects such as: Recommended Practice for the Preparation of High-Carbon Steel, Preparation of Zinc Base Die Castings for Plating, Preparation of Copper and Copper Alloys for Plating, Preparation of Stainless Steel for Plating, and Recommended Practice for Plating on Aluminum. The foregoing partial list of subjects results from the work of one of the subcommittees of Committee B-8. Typical of the work of another subcommittee are Mr. Bowman's paper on luster measurements and Mr. Mendizza's paper on the salt-spray test. Other subjects, either published or under preparation by this same group, involve tests on electrodeposited metallic coatings for thickness, porosity, adhesion, ductility, hardness, and stress. Typifying the work of two other subcommittees are the papers describing performance tests of copper-nickel-chromium combination coatings as well as zinc, cadmium, lead, and supplementary conversion coatings on certain of these metals. The groups concerned with such performance studies are continuing their work and have programs under consideration for other types of metallic coatings.
History of ASTM Committee B-8
Authors: Blum William
Published: August 2009

It was natural that among the early activities of ASTM Committee A-5 on Corrosion of Iron and Steel and Committee B-3 on Corrosion of Non-ferrous Metals and Alloys, consideration should be given to the use of protective metallic coatings. When Committee A-5 was organized in 1907, the principal metallic coating used on steel was zinc, then generally applied by hot-dipping. In 1922 when Committee B-3 was organized, the metallic coatings on non-ferrous metals were usually applied by electroplating, but for appearance rather than for protection. The first recorded specific studies by ASTM on electroplated coatings were started about 1927 by A-5 Subcommittee on Hardware Specifications (now Subcommittee XIII). In this investigation, steel articles of many shapes, including those used in pole-line hardware (plates, angles, washers, bolts, and nuts) were coated by various methods, including hot-dipped, sherardized and electroplated zinc; electroplated cadmium; hot-dipped lead; and hot-dipped aluminum. Specimens of each kind were exposed in several locations, including New York, N. Y., Sandy Hook, N. Y., Pittsburgh, Pa., State College, Pa., and Key West, Fla.; and were inspected at intervals by interested members of the subcommittee. The results that were reported within a few years were unfavorable to the electroplated zinc and cadmium coatings. In the light of present knowledge, this observed inferiority of electroplated coatings was at least partly caused by the following: 1. The specimens were all prepared under commercial conditions, with no special efforts to produce uniform coatings. In other words, they were typical of what was then being done, rather than of what might be done. 2. By the methods then used commercially, the electroplated coatings were much thinner than the hot-dipped coatings. (This is a valid argument for the use of electroplating when only thin coatings are required.) 3. Many of the shapes, especially the angle irons, were such that electroplating did not furnish as nearly uniform coatings as were normally produced by hot-dipping. Hence the plated coatings usually failed at those points where the coatings were abnormally thin. 4. No systematic effort was then made to measure the average or minimum thickness of the coatings produced by the various methods. This apparent oversight was caused in part by the lack, at that time, of convenient reliable methods for measuring the minimum thickness of coatings.
The Standard Salt-Spray Test—Is it a Valid Acceptance Test?
Authors: Mendizza A.
Published: August 2009

The salt-spray test was originally-developed some 40-odd years ago (1) for the purpose of quickly evaluating the resistance of plated coatings to attack by marine atmospheres. Through the years an ever increasing use has been made of this test for the purpose of controlling quality of electroplated articles. Today the salt-spray test is employed not only to evaluate the quality of all types of electroplated coatings, both of the cathodic and of the anodic type, but is also frequently used for testing completely assembled equipment. Many specifications contain requirements based on performance in the salt spray, compliance with which is rigidly enforced. The endpoint requirements will vary, depending on the type of coating tested or on the combination of dissimilar metals used. In the case of electropositive coatings, the endpoint is usually specified in terms of a permissible number of corrosion spots per unit area that will develop in a given time. Electronegative coatings, such as zinc and cadmium on steel, are evaluated by their ability to prevent rust formation. Notwithstanding its widespread use, the salt-spray test has frequently been subject to criticism for being unrealistic and misused (2, 3, 4). Its role as a forecaster of service performance has been challenged, and failure to correlate salt-spray test results with performance to actual atmospheric environments have been reported in the literature (5, 6, 7). Inability to obtain reproducible results, both within any one test box as well as amongst several boxes, has also been unofficially reported by many users of this test. Although its shortcomings are thus generally recognized the salt-spray test continues to form a part of many finish specifications, both in industry and government agencies. The lack of a more suitable replacement is the most frequent reason given for the retention of the salt-spray test as a standard test. The American Society for Testing Materials has standardized a salt-spray testing procedure with its Method B 117. The uniformity of conditions within the test chamber operated in accordance with this test procedure is controlled primarily by three physical parameters; rate of salt-fog precipitation, concentration of collected salt solution, and ambient temperature. Rather wide limits are allowed for the precipitation rate. The concentration of collected solution and the temperature are kept within much narrower limits. In addition, the chemical purity of the salt and the pH of the salt solution are also controlled. No provisions are made for calibrating the salt-spray test chamber against some standard. Government specifications on the salt spray are in the main similar to those covered by the ASTM method.
Methods of Testing Sandwich Constructions at Elevated Temperatures
Authors: Kuenzi Edward W.
Published: August 2009

Defense demands for aircraft and guided missiles with superior operational capabilities have necessitated the development of new types of airframe construction. Such construction must maintain its stability under loads induced by high speeds at elevated temperature. The use of structural sandwich construction comprising thin high-strength facings on thick lightweight cores constitutes a very promising construction for structural components of such high speed aircraft. The advantages of sandwich construction in providing great stiffness and strength per unit weight have been amply demonstrated for many combinations of materials at ordinary temperatures. However, sandwich constructions are comprised of several materials—facing, cores, and material used to join or bond facings to cores; hence its performance can be determined only after due consideration of structural properties of each material. Also, it may be possible in assembling a sandwich construction to alter somewhat the characteristics of the components by the assembly processes. Thus, it appears logical to evaluate sandwich behavior by tests of assembled sandwich construction at least until fundamental properties of component parts at operating temperatures can be found. A research project for the evaluation of various sandwich constructions at elevated temperatures was established at the U. S. Forest Products Laboratory by the Materials Laboratory, Wright Air Development Center. The testing techniques employed for evaluation of the constructions are described and discussed in this paper.
Metal-to-Resin Adhesion as Determined by a Stripping Test
Authors: Snoddon William J.
Published: August 2009

Adhesion of metals to resins may be determined by curing a resin in contact with a metal foil and subsequently stripping the foil from the resin under controlled conditions. Following this procedure, applications are given where a liquid epoxy resin was cast and cured over aluminum, brass, and steel foils. Tests were run at several stripping angles and stripping speeds. The effect of several epoxy resin hardeners on metal-to-resin adhesion is presented. To a lesser extent data are presented on the adhesion of aluminum foil to glass reinforced epoxy resin and polyester resin laminates. Modification of the stripping procedure to permit determination of adhesion of protective coating resins to metals is mentioned.
An Ultrasonic Technique for Non-Destructive Evaluation of Metal-to-Metal Adhesive Bonds
Authors: Arnold James S.
Published: August 2009

The use of adhesives in the fabrication of metal composite structures is a technique that has become very useful in many fields of design and manufacturing, particularly those related to aircraft. The utilization of adhesive materials has made it possible to satisfy design requirements that would be extremely difficult or impossible to satisfy by the use of more conventional fastening methods. Many factors affect the quality of adhesive bonds, and several types of destructive and non-destructive tests have been proposed and used in efforts to measure bond quality. Destructive tests on adhesive-bonded samples are widely used; they determine bond quality by destroying the bond, thus making the assembly unusable. As a result, the evaluation of usable bonds is based on statistical and process control variables, which is quite satisfactory in some applications. There are, however, many applications in which a direct indication of bond strength in usable assemblies is necessary. Situations in which an adhesive bond contributes to the structural integrity of aircraft exemplify these applications. The need for a non-destructive method of bond evaluation has thus arisen, and only with the development of such a method will designers be able to exploit fully the adhesive fastening technique. The adhesives used in such applications are complex organic materials. The application of the adhesive requires extreme cleanliness and rigid process control. Most of the adhesives attain their strength at the conclusion of a “cure” at elevated temperature. The most common types of construction for aircraft employ the adhesive to fasten two or more pieces of metal together in a lap joint or laminate and in the construction of “sandwich,” which consists of a core of aluminum honeycomb or other material, covered with facings or skins, the entire sandwich being adhesive-bonded. Metals and plastics are the usual materials. Figure 1 shows examples of lap joint and sandwich construction. The state of knowledge of the adhesive bond does not appear to be sufficiently advanced to allow a direct analytic approach to the problem of devising a nondestructive test technique, although publications indicate that in some circumstances, at least, the service properties of an adhesive bond can be predicted from ultrasonic measurements of the complex elastic modulus in simple geometric configurations. The complex elastic modulus is one that includes the effects of viscosity in describing the stress-strain relationship in situations of vibratory forcing. The conversion of mechanical to thermal energy (loss) is thus included in the system description.
Nondestructive Testing of Bonded Metal Sandwich Structures
Authors: Anderson Richard E.
Published: August 2009

In the continuing effort to increase the speed of military aircraft, the goal of every aircraft designer is to reduce the weight. By increasing jet-engine thrust and reducing airframe weight, speeds previously unattainable are now commonplace. This weight problem has been complicated by the fact that no sacrifice in structural integrity can be tolerated. This challenge has been met by the development and extensive use of sandwich structures which consist of lightweight cores joined between two thin facings. Balsa wood, foamed plastic and paper, aluminum or steel honeycomb are generally employed as the lightweight core material. Fiberglass-reinforced plastic laminates or thin gage metal skins are generally employed as the facings. Facings are bonded to the core with structural adhesives or with brazing in the case of an all-steel construction. At North American Aviation, effort has been concentrated on the all-aluminum sandwich—aluminum-honeycomb core bonded to aluminum facings with epoxy adhesives. The core and facings are contoured to any desired shape prior to the bonding operation.
Operation of Diesel Locomotives with Dual-Fuel Systems
Authors: Garin Paul V.
Published: August 2009

As the result of an extensive research program to develop less critical fuels for use in its diesel locomotives, the Southern Pacific Co. adopted the so-called “economy” distillate fuels for general service early in 1954. Since that time, these distillate fuels, with minimum cetane rating of 34 and maximum sulfur content of 1 per cent, have been successfully used in diesel locomotives with resultant economies both to the railroad and the oil supplier. With the satisfactory use of less critical distillate fuels well established, the Southern Pacific fuel research effort was directed to the possibilities of employing even lower cost fuels in its locomotives. During the initial stages of the research program, a successful test was conducted with an experimental fuel identified as X-1. This fuel, which was a blend of heavy straight-run distillates and cracked stocks characterized by high viscosity (72 sec Saybolt Universal at 100 F) and high pour point (55 F), required heating to approximately 150 F for injection. The fuel was of a waxy nature, containing relatively high (0.90 per cent) sulfur content, but having a cetane number of 48. By means of a heat exchanger using cooling water, the fuel was heated to injection temperature. Two Electro-Motive Division (EMD) model 567-B engines in main line freight service were equipped with heat exchangers to handle X-1 fuel. Underbody fuel tanks were insulated with a mastic coating to retain heat, and a circulating heating system from the tank through the heat exchanger and back to the tank maintained necessary temperature for this high pour point fuel in the tank. After the test period of six months in main line freight service was completed, during which each test unit consumed approximately 100,000 gal of X-1 fuel, inspection was made of assemblies removed from each unit. The appearance of engine parts and wear measurements were considered normal in all respects as compared to units operating on regular straight-run distillate fuel.
Diesel Locomotive Lubricating Oil Requirements as Related to Fuels
Authors: Broughten J. L. , Moore C. C.
Published: August 2009

There has been considerable activity in the field of economy fuels for locomotive diesel engines. However, little attention has been directed toward the study of crankcase lubricants for use with these fuels. It is well known that fuels and lubricants have interrelated effects on engine deposits and wear. Experience has indicated that joint studies of fuels and lubricants are needed to obtain the most savings from economy fuels. For example, a knowledge of these factors must be used in setting up overhaul and maintenance procedures. The current interest in residual fuels seems to justify a review of some of the ways in which changes in fuel quality have affected the lubrication of diesel locomotives in the past. It seems certain that this same pattern will confront the railroads in the future as they make still further changes in their fuels to obtain economies. In the early days of diesel locomotives, the engine builders were faced with the problem of adapting their power plants to the varying speed and loads of railroad operation. For this fairly severe service, and because diesel engine reliability had not been fully proved, the engine builders recommended the use of high-quality diesel fuels. These were fuels of high cetane numbers, low sulfur contents, and low boiling ranges. Many railroads operating diesel engines with low brake mean effective pressures (BMEP), obtained satisfactory performance with medium viscosity index, nondetergent lubricants when these fuels were used. Most of these lubricating oils contained some type of oxidation inhibitor. During this period it was found that the source of the lubricating oil base stock and the method of refining affected the performance of nondetergent oils as regards valve, ring, piston, and air port deposits. The oxidation stability of the lubricant and the nature of the combustion deposits formed were found to be of great importance. Even when using high-grade fuels, engines lubricated with poor quality nondetergent oils showed excessive deposits. During these early stages of locomotive diesel operation a great deal of effort was spent in improving and modifying engine design. The initial development of detergent-type oils was being carried out during this same period. On account of the rapid changes occurring in both fields, detailed knowledge of the fuel-lubricant relationship was difficult to obtain.
Nondestructive Testing Applied to Railroad Materials and Equipment
Authors: Pedsick A. S.
Published: August 2009

Periodic inspection, maintenance, and tests are of paramount importance in railroading since safety of operation must be assured at all times. “Safety First” is an old slogan in railroading dating back to the early days in the industry. It is usually associated directly with train operation, but successful train operation also depends on quality control of the materials and parts used on the motive power and car equipment as well as on proper maintenance of this equipment and track, roadbed and related facilities so that all will serve their intended function with the desired reliability and safety in service.
Introduction
Authors: Gambrill C. M.
Published: August 2009

This Symposium on Lubricating Oils presents the results of some of the activities of Research Division III and of Technical Committee B of ASTM Committee D-2. ASTM Committee D-2 on Petroleum Products and Lubricants is concerned with specifications, standard test methods, and recommended practices in the field of petroleum products and lubricants. Research Division III is responsible for the development and standardization of physical and chemical methods, and research and development projects for the determination of elements in petroleum, petroleum products, and additives used in petroleum products. Technical Committee B, on the other hand, is concerned with the specifications, methods of test, and nomenclature for lubricating oils. Research Division III is happy to join with Technical Committee B in sponsoring this symposium. In addition to these responsibilities, problems of a technical service nature are often considered. This type of service offers an excellent opportunity for consumers and producers to meet together in cooperative effort to overcome mutual problems in the use of petroleum, its products, or lubricants. These technical service studies require extensive research by the member laboratories to develop satisfactory answers to these problems.
The Application of X-Ray Spectrography to Refinery Control of Additive Metals in Lubricating Oils
Authors: Davis Elwin N.
Published: August 2009

During the past 30 years the performance and quality of petroleum lubricants have been vastly improved. These improvements have been made possible by the application of new refining techniques and the invention of hundreds of additives to change and supplement the oil's natural properties. The use of these many additives, although of great utility to the consumer, has added many problems for the manufacturer of lubricating oils, not the least of which is that of quality control analyses. Many of these additives are organo-metallic compounds that may be added to the oils in a wide range of concentrations. The simplest control test for these additives is to analyze for the metallic component. The blending of lubricating oils whether done manually or by the use of automatic proportioning equipment is considered a batch operation, and before a batch can be considered complete and can be removed from the blending vessel, it is necessary to have the control test completed. It is obvious then, that if refineries are to use their lubricating oil blending equipment at its highest efficiency, the laboratory must be able to provide quick and accurate control analyses. To accomplish this, a number of methods such as colorimetric, polarographic, flame photometric, emission spectrographic, and X-ray spectrographic were considered to replace the conventional wet chemical methods.