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By L. L. Wyman

Since the presentation, by the writer, of the initial paper on the embrittlement of copper,1 the subject has been investigated further along two separate lines. The first series of investigations involves the "double-deoxidized" coppers, while the second series is devoted to single deoxidizers other than those used in the investigations reported upon last year. The object of these experiments is to develop a type of copper that will show the minimum of detrimental effects after having been exposed to alternate oxidation and reduction. The fabrication of this material necessitates the use of alternate oxidizing and reducing atmospheres, at temperatures ranging up to 900" C. Following this treatment it is essential that the soundness and strength of the copper be unimpaired, even in sections of only a few thousandths of an inch in thickness. Materials The ensuing report embodies three separate groups of materials, which may be classified as follows: 1. Double-deoxidized copper using silicon and calcium boride. 2. Copper deoxidized with calcium. 3. Double-deoxidized copper using constant calcium content (0.075 per cent) plus silicon, or calcium boride. Last year, T. S. Fuller, of the General Electric Research Laboratory, suggested that if a properly deoxidized copper had sufficient deoxidizer residual in the material, this excess material might increase the resistance of the copper to the oxidation reduction cycle. In consequence of this suggestion, two small lots of "double-deoxidized" copper were prepared. The first, lot A, was made by adding 0.03 per cent silicon as the deoxidizer, following this by an addition of 0.55 per cent calcium boride immediately before pouring. The second, lot B, contained the same ingredients, but these were added in the reverse manner. Inasmuch as these lots were tested separately from the materials about to be described, it must be borne in mind that the materials cannot be grouped together, and are not directly comparable.

Jan 1, 1933

By Robert F. Mehl

THE gamma-alpha transformation in iron and iron-rich alloys is of such practical and theoretical importance that many papers have been published upon the subject relating to critical temperatures, transforma-tion rates and accompanying property changes. Although crystallo-graphic studies are of less immediate practical usefulness, the opportunities which these offer to furnish data, on the basic atomic movements which characterize the transformation are not to be neglected1. The early work on the crystallography of this transformation has been reviewed in the fourth paper of this series2 since then several important papers have appeared. Our present, knowledge may be briefly summarized as follows. Kurdjumow and Sachs, working with a 1.4 per cent carbon steel3, established the orientation relationships subsisting between the face-cen-tered gamma and the metastable tetragonal lattices in freshly quenched martensite, and between the face-centered gamma and the body-Centered alpha lattices in tampered martensite. The orientation relationship observed in the latter case may be stated in terms of planes and directions observed to lie parallel in the two lattices: { 111 }Y//{110}a [110]Y//[111]a

Jan 1, 1937

By Frederick Clapp

INTRODUCTION - SCOPE OF DISCUSSION There has hitherto been no systematic effort to make public the available information on petroleum in South America and the object of this paper, therefore, is to broadly discuss the subject as it pertains to South America as a whole, endeavoring to collect in readable form what is known regarding individual fields. This article is not intended to exhaustively discuss individual fields, or to solve the many complicated problems regarding petroleum and natural. gas in the various republics, since those necessitate years of study and work by petroleum geologists, engineers, financiers, and drillers. Neither. can the reader expect absolute accuracy in all statements, since this is impossible at the present time. The writer has, of course, attempted to be correct in all cases, but in a review involving so many countries and extending over so many, phases of the subject, it is to be expected that some errors will have crept in.

Jan 10, 1917

By T. W. Lippert

CUBA fancies herself the "pearl of the Antilles" and, by many, Jamaica is called "blessed." But far to the southward lies what is seemingly the Caribbean's most glittering jewel, the sparsely-settled, Spanish-speaking United States of Venezuela, indeed blessed by nature to a lavish degree. Not a large country, Venezuela is leaping from the donkey to the airplane under the impact of its natural wonders. Angel Falls, dwarfing Niagara and seldom seen by man, is hidden in the cold, primitive and unexplored Guiana highlands along the southeast border. A few hundred miles northwest are the low and torrid coastal plains from which gush unlimited black-gold streams of oil. About midway are the Llanos-low-lying, savanna-type grasslands, beneath which large deposits of bauxite are as yet barely touched by the explorer's diamond drill. And jutting starkly upward 2000 ft from a surrounding expanse of savanna is a small mountain (see front cover), 11 miles long and 1 mile wide. It is, or was, La Parida.

Jan 2, 1950

By Tom Westgarth

As papers are placed before you upon large gas-engines in Belgium and Germany, it was considered that some information should be given upon the same subject in Great Britain. I therefore agreed to compile these notes, which I have made very short in view of the somewhat full nature of the other papers presented to this meeting, and considering the complete nature of the many publications which have been made recently upon the subject of large gas-engines. I give below Tables I. to VI., showing the number and particulars of large gas-engines which have been built or are building by British makers, and in view of the growing size of gas-engines I have concluded that engines of less than 500 h.p. cannot now he included in the category of large gas-engines, and therefore I have not considered engines under that power. Table I.—-" Oechelhauser " Type Gas-Engines. Built or Building by William Beardmore Co., Limited, Glasgow Indicated ! Engines. Horse-Power Type. Nature of Work. Gas Used. 6 2,500 Twin cylinder. Dynamo. Producer. 1 in Single cylinder. Rolling-mill. Producer. 4 1,250 Twin cylinder. Dynamo. Producer. 2 1,250 Single cylinder. Dynamo. Producer. 4 625 Single cylinder. Dynamo. Producer. 1 625 Single cylinder. Rolling-mill. Producer. 1 625 Single cylinder. Air compressor. Producer. 2 500 Single cylinder. Air compressor. Producer. 7 500 Single cylinder. Cement-mill driving Producer. Total, 28 engines ; 32,600 indicated horse-power. * Presented at the Joint Meeting of the Iron and Steel Institute and the American Institute of Mining Engineers, London, July, 1906, and here published under a mutual agreement between the Councils of the two Institutes.

Jan 1, 1907

By C. R. St. John, R. W. Lindsay, Charles R. Austin

MANY of the factors influencing the creep behavior of ferrous alloys have been investigated and reported upon in the literature, including such variables as grain size, steelmaking practice, nature and stability of the microstructure, and the effect of alloying elements in steels. However, with respect to the latter, the microstructures involved are usually heterogeneous and as a result the effect of the addition is related to its effects on the various phases present in the microstructure. In the instances where this structure consists of ferrite and carbide, the behavior of the alloy addition will be related to its action in strengthening ferrite and in opposing temperature softening of ferrite as well as coalescence of carbide. The present paper is the third in a series comprising a comprehensive review of investigations on the properties of iron binary alloys. 1.2 Its purpose is to describe the results of isolating one microstructural phase, namely ferrite, and studying its creep characteristics in both the unalloyed and alloyed conditions. This should aid in establishing to a large degree the importance of ferrite in the creep behavior of steels consisting of the previously mentioned ferrite-carbide aggregate. REVIEW OF PREVIOUS WORK In view of the fact that the present investigation deals only with the effects of silicon, manganese, chromium, molybdenum, nickel, and cobalt, and to a certain extent with the effects of carbon, the review of previous literature will be confined to these elements. Practically no references were encountered dealing with the influence of these elements on the creep characteristics of the isolated phase. However, various contributions have dealt with the creep behavior of low-carbon steels alloyed with the elements under consideration. A particularly concise review in this respect is given by Bullens (Battelle)3 and much of this material has been drawn upon. The definite improvement in creep resistance and high-temperature strength conferred by molybdenum is well known. Published suggestions by the A.S.M.E.4 permit of an increase of some 2000 to 5000 lb. per sq. in. in permissible design loads over a temperature range from 650° to 1000°F. as a consequence of additions of 0.40 to o.60 per cent of this element in carbon steels of the order of o.25 to o.35 per cent carbon content. Babcock and Wilcox Tube Co.5 has published data showing the pronounced increase in stress necessary to cause one per cent creep per 10,000 hr. when additions of 0.5 or 1 per cent molybdenum are made to a plain carbon steel. These data apply to temperatures over a range from 800° to 1000°F.

Jan 1, 1945

By C. H. Mathewson, Kent R. Van Horn

Copper and the copper-base solid solutions readily form twin crystals when plastically deformed at a suitably elevated temperature or annealed after cold deformation. In fact, no feature of the microstructure of these materials is more prominent or characteristic than these straight-sided bands or simple lines of division which sometimes come from groups of thin polysynthetic lamellae, penetrating part way or wholly through the parent grain substance, but often divide the grain into a few or perhaps only two crystallographically related parts. Nearly always the bands as seen in the usual microscopic examination of a specimen come into vivid contrast with the adjacent crystalline material owing to the inherent difference in orientation. Bands which under special conditions of orientation cannot be seen with vertically incident light are often visible under oblique illumination and, when this fails, contrasting effects usually may be obtained by using polarized light. There is no longer any doubt that these synthetic banded structures obtained in the ordinary course of working and annealing are due to twinning of the spinel type which was observed long ago in a number of metals crystallizing in the isometric system.' It has been customary in metallurgical literature to designate these synthetic twins, which grow into prominence during an annealing process, as "annealing twins" without regard to the actual mode of their formation, which is, indeed, obscure and with scant recognition of the fact that prior deformation is essential, no twins having been observed in metal of known unstrained history. This is questionable; especially in view of the fact that in a number of metals and minerals, reorientation into the twin configuration is known to occur as a result of a simple shearing mechanism along the recognized twinning planes and the

Jan 1, 1930

By W. M. McKewan, R. G. Olsson

In order to improve the understanding of the iron oxide reduction mechanism, the rate of equal molar diffusion of hydrogen and water vapor was measured through disks of porous iron and alumina. The measuretneizts were made at atmospheric pressure at 800°, 900- , and 1000°C. It is shown tint the reduction of dense hematite pellets with hydrogen at these temperatures and at atmospheric pressure is to a great extent limited by gaseous diffusion between the bulk-gas phase and the iron-wustile interface. THE investigation of the reduction of iron oxides with hydrogen has been the subject of numerous papers. Although the effects of temperature, pressure, and gas composition on the rate of iron oxide reduction have been studied, the actual mechanism of the reduction process has not been definitely determined. As a means of improving the understanding of the mechanism, the rate of equal molar counterdiffusion of hydrogen and water vapor was measured through porous iron and porous alumina disks at reduction temperatures. The alumina was used as a basis of compari-son because its pore structure is homogeneous and independent of temperature. The porous iron was prepared by the reduction of dense hematite disks with hydrogen at the temperature of the subsequent diffusion experiment. The hematite disks were made from pellets that were identical to those used by McKewan1,2 in his study of iron oxide reduction with hydrogen. In these investigations the weight loss and rate of movement of the various interfaces were measured as a function of the reduction temperature and gas composition. With these reduction data and the presently reported diffusion data it is possible to determine the importance of H2-H2O transport between the bulk-gas phase and the Fe/FeO interface to the reduction of dense hematite. APPARATUS AND PROCEDURE A porous iron or alumina sample was held in the base plate of a sealed canister containing porous granular wustite, as illustrated schematically in Fig. 1. The canister was suspended from an automatic recording balance in a vertical tube furnace through which flowed hydrogen and water-vapor mixtures of known composition at atmospheric pressure (0.96 atm). Hydrogen from the gas stream diffused through the porous sample, reducing the wustite in the interior of the canister. The water vapor that was formed diffused back to the gas stream. The rate of diffusion was determined from the recorded weightloss data. The furnace, automatic balance, and gas-metering equipment have been described previously.2 The main body of the canister and the tubing extension were made of stainless steel while the base plate was made of high-purity iron. The main body of the canister was % in. in diam. It held approximately 6 g of porous granular wustite that was prepared by reducing 0.1- to 0.2-cm-diam specular hematite particles at 900°C with an H2-H2O mixture of a composition near the iron-wustite equilibrium value. The upper end of the 1/8-in.-diam tubing extension was sealed with a segment of plastic tubing and a tubing clamp. The temperature at the top of the furnace was sufficiently high so that no water vapor condensed inside the extension. In the experiments with porous iron, iron oxide samples were prepared from reagent-grade hematite that was pressed and sintered in a manner previously described.' The resulting pellets had a density of 5.15 ± 0.05 g per cu cm. Each pellet was centerless-ground

Jan 1, 1967

By Basil Prescott

Resume.-The district of Santa Eulalia lies 12 miles to the southeast of the city of Chihuahua, Mexico. The ore deposits occur in a Cretaceous limestone of unknown thickness, overlain by a series of rhyolitic tuffs and flows. The limestone is very gently folded and is cut by several systems of fissures, of which only those with a general north-south strike are pre¬mineral and control the deposition. The deposits are of two main types; the earlier silver-bearing iron sulphide types occurs as high-grade tabular bodies resembling veins and as large masses of relatively low-grade ore. The gangue of this type is composed of lime-iron silicates that point toward a close association with an igneous rock mass which has not yet been encountered. In the later silver-lead-zinc type the ore occurs in vertical chimneys and horizontal mantas, principally as oxides, though at a depth of 1,500 ft. some sulphides have been encountered. During oxidation the ore chambers have increased in size owing to the solution of the walls by the sulphuric acid generated in the process, and a substitution has taken place of nearly one-half part by weight of the original constituents of the ore, by newly introduced elements and radicals. Both types are believed to have come from greater depths than those yet reached by mining, and their ultimate source, from a consideration of similar deposits, is believed to be an igneous rock in contact with the limestone at some horizon below. The deposits are believed to have been formed at unusually great depths, as indicated by the proved great vertical range of the silicate minerals coupled with the absence of the igneous rock, and by the practically unchanged character of the silver-lead-zinc ores as far as developed. The volcanic capping is believed to be distinctly later than the economically important ore deposition.

Jan 2, 1915

By A. M. Gow

The trend in ball milling has been toward mills of larger diameter, but without fundamental laws as a guide. The speeds at which mills are run have been a matter of cut-and-try. This paper deals with both diameter and speed and proposes to show the laws which apply to some laboratory ball mills, ranging in diameter from 18 to 42 in., run at various speeds. The correlation of power, speed and grinding rate of the respective mills will be shown by curves of markedly significant similarity. Before presenting the results some consideration will be given to the mechanics of ball milling. Mechanics and Theory of Ball Milling As early as 1904, Herman Fischerl reported observations on specially constructed ball mills which allowed the paths of balls to be studied. The following conclusions were drawn: 1. Balls do not grind the ore, but crush it by impact. 2. At slow speeds the balls roll down the inclined heap, but at higher speeds the balls close to the wall adhere to it until they reach a certain height, whence they are thrown through an arc to the bottom. 3. The falling balls do not come down in clusters, but in series, the balls of each row keeping to their own line of flight according to their distances from the wall while ascending. 4. A further increase in speed results in the balls adhering during the whole of the circuit to the side of the drum. (This centrifuging speed may be called the "critical" speed and may be taken as a reference basis, since it is a constant function of the diameter.)2

Jan 1, 1930

By Wm. Reuben Webster

BRASS is an alloy of copper and zinc. The brasses (using this term to denote all useful proportions of the two constituents) are the most valuable and widely employed of all [ ] nonferrous alloys, because of their high resistance to ordinary corrosive agencies and the very wide range of properties that may be imparted to them by variations in the proportions of the constituents and by variations in mechanical treatment and heat-treatment. Fig. I shows the normal physical properties, as determined by standard tensile tests, of the series when in the annealed condition. Fig. 2 shows the effect of varying amounts of cold-working on an almost pure brass containing 70 per cent copper and 30 per cent zinc. Fig. 3 shows the effect of annealing at various temperatures on the same alloy. This effect is somewhat modi- [ ] fied by the degree of cold-working to which a brass has been subjected, as shown by Fig. 4. A fourth test, which is empirical, has been found useful because of its simplicity the hot hammer test. Samples 1/2 in. in diameter and 3/4 in. long are placed in a suitable furnace. These are withdrawn one at a time at successively higher temperatures and are subjected to the blow of a drop hammer weighing 50 lb. with a drop of 4 ft. The percentages of reduction in length of the cylinders are plotted against temperatures and give a comparative measure of plasticity at different temperatures. The results of this test on several

Jan 1, 1942

By F. L. Ransome

The following paper aims to present in a much condensed form the salient results of a detailed geological study of the Bisbee quadrangle, Arizona, carried on during the latter part of the year 1902. It is essentially an abstract of the final official report which will shortly appear in the series of professional papers of the U. S. Geological Survey, accompanied by maps, sections and illustrations. I. Geography. The Bisbee quadrangle, which includes the Warren mining district, lies in Cochise county in the southeastern part of Arizona. It is inclosed between the meridians 109" 45' and 110" 00' and the parallels 31" 30' and 31" 201, the latter being locally the Mexican boundarg line. The area of the quadrangle is about 170 square miles, and includes the southeastern half of the Mule Mountains, one of the smaller of the isolated ranges characteristic of this part of Arizona. The Mule Mountains, while less markedly linear than the Dragoon, Huachuca, Chiricahua, and other neighboring ranges, have a general NW-SE. trend. They may be considered as extending from the old mining town of Tombstone to the Mexican border, a distance of about 30 miles. On the northwest they are separated by the broad, flat floor of Sulphur Spring Valley from the Chiricahua Range, and on the southeast by the similar broad valley of the Rio San Pedro from the Huachuca Range. The maximum width of the range is about 12 miles, and its greatest elevation attained by Mt. Ballard, west of Bisbee, is 7,400 ft. above sea-level. An index-map, showing the geographical position of the Bisbee quadrangle, is shown in Fig. 1. The town of Bisbee (Fig. 2), with an estimated population of 6,000, is crowded into a few narrow confluent ravines near the

Jan 1, 1904

By H. C. H. Darley

The influence of particle size and concentration on the development of chip hold-down pressure (CHDP) was studied in an apparatus designed to measure the change of filtration rate during the first second of the filtration process. CHDP is controlled by the "bridging" particles (i.e., particles in the 50 to 0.2 micron range), whereas filter loss is controlled by the colloid fraction. The results indicated that a fast drilling fluid with a low filter loss could be obtained if the concentration of bridging solids and the viscosity were kept very low. A novel group of drilling fluids, which we have named colloid emulsions, was developed to meet the above requirements. These colloid emulsions are made by dispersing art oleophilic colloid in oil and emulsifying about 5 per cent of this dispersion in water or a dense brine. Good results have been obtained in field trials with emulsions which use asphalt as the oleophilic colloid. INTRODUCTION In recent years it has been found that fast rates of penetration can be maintained in hard formations by using "clear" water as a drilling fluid. In some cases, however, water cannot be used because the very high down-hole filter loss creates various difficulties in drilling, in logging, or in producing the well. It then becomes necessary to "mud up", which results in a decrease in drilling rate. The reason that mud decreases drilling rates is a complex subject which has been well covered by such authors as Garnier and van Lingen, Cunningham and Eenink,' and van Lingen.3 One of the principal factors involved is the tendency of the drilling fluid to develop a filter cake on the bottom of the hole. The pressure differential which develops across this filter cake opposes the action of the bit in dislodging chips from the rock. This pressure differential is referred to by Garnier and van Lingen' as the chip hold-down pressure, which is denoted by the initials CHDP in this paper. The work described in this paper was undertaken to develop a drilling fluid which would minimize CHDP but which would still have a low filter loss—in other words, a fluid which would deposit a filter cake on the sides but would lay little or no filter cake on the bottom of the hole. EVALUATION OF CHDP EXPERIMENTAL Conditions governing the growth of filter cake on the sides of the hole are obviously different from those on the bottom of the hole. On the sides of the hole, cake will form continuously but at a decreasing rate, until eventually the rate of growth will equal the rate of cake erosion by the mud stream.' On the bottom of the hole, each time a bit tooth dislodges a chip the cake is removed, a fresh rock surface is exposed, and the filtration process must start over again. Thus the CHDP is determined by the amount of cake which can form in the interval between successive tooth strikes at a particular spot, normally a fraction of a second. Our first step therefore was to study filtration rates over the first second or so of the filtration process. These tests were conducted in the simple type of dynamic filter cell shown in Figs. 1 and 2. In this cell the mud was filtered through a train of rock cores while rotating blades kept the mud flowing over the surface of the core. The procedure was to evacuate the cores to 0.05 mm of mercury, saturate with brine, and assemble in the holder under brine. The permeability of the core train was then determined. A plastic seal was placed on the face of the core train, and a rip cord was attached from the seal to one of the blades. At the start of the test, 500 psi was applied to the mud, and the meniscus in the capillary measuring tube was adjusted to zero. When the blades were started, t,he seal was ripped from the face of the core, and filtration began. The filtration rate was at first measured by photographing the advance of the meniscus in the capillary tube. Using

Jan 1, 1966

By Shun-ichi Satoh

STUDIES by many authorities have proved that nitrogen exerts an injurious influence upon iron and steel, but in the casehardening of steel by carbon, nitrogen has the advantage of accelerating the process of cementation. Its influence upon special steels is quite remarkable; it can produce the hardest layer ever known in metallurgical products-a fact hit upon by A. Fry and studied and ascertained by L. Guillet. As there have been very few investigations on the influence of nitrogen on special steels, the writer has listed important articles dealing with this problem and has conducted experiments on nitrification. He also has tested the influence of nickel upon the penetration of nitrogen in electric-arc welding.

Jan 1, 1929

By L. S. Austin

I. Introduction............ 431 II. Organization............ 432 III. Production............ 434 IV. Transportation............ 435 V. Sampling..........436 VI. Concentration............ 440 VII. Blast-Furnace Plant........... 442 1. Construction........... 442 2. Operation............ 450 VIII. Advantages of Large Furnaces........ 455 1. Saving in Fuel........... 455 2. Saving in Jacket.Water..... 455 3. Quick and Large Discharge of Matte and Slag... 455 4. Decrease of Incrustation... 456 5. Elasticity of Operation..457 6. Large Flow Through Fore.Hearths...4. 57 7. Alterations Without Interruption..458 8. Variations in the Composition of Slag....458 9. Less Labor-Cost.......... 458 10. Less Initial Cost.......... 460 IX. Briquetting.Plant........... 460 X. Roasting-Plant............ 462 1. Kilns............ 462 2. Reverberatory Furnaces...468 XI. Converter-Plant........... 474 1. Construction ..........474 2. Operation.......... 476 XII. Flues and Stacks........... 478 XIII. Arsenic-Plant............ 480 XIV. Coke-Washing Plant.... 452 XV. Slime.Ponds ........... 483 XVI. Brick-Plant............ 484 I. Introduction. The Washoe plant; in Anaconda. Mont., together with the local street-railroad, ranches. a foundry and machine-shop. A

Jan 1, 1907

By Sidney Powers

Contents Page Distribution of fields..................................................... 490 History of development.................................................. 492 Origin of oil............................................................ 493 Structure, accumulation and migration..................................... 494 Reservoir rocks......................................................... 495 Methods of drilling and exploration....................................... 496 Oil-field statistics........................................................ 498 Description by regions: United States: Appalachian region.................................................. 498 East-central states............................................. 503 Kansas............................................................ 504 Oklahoma.......................................................... 505 Texas........................................................... 510 Arkansas........................................................... 518 Louisiana.......................................................... 519 Mississippi......................................................... 520 Rocky Mountain region.............................................. 520 Cahforn~a ......................................................... 523 Canada.............................................................. 527 Mexico.............................................................. 529 Cuba............................................................... 532 Bibliography........................................................... 532 The purpose of this brief account of the occurrence of petroleum in North America is to make available to those who have a knowledge of geology, but who are not engaged in the petroleum industry, a few salient facts about the location of oil and gas fields, their productivity, the important structural types of accumulation and the age of the rocks containing petroleum. A few useful data and statistics are furnished, yet not complete statistics that are available elsewhere. Geology has been treated in simple terms because the reader is presumed to have little interest in the names of formations and of oil sands. Mineral deposits are more or less analogous. Whether oil or metals, minerals are found in rocks, largely in sedimentary rocks which carry water or have at one time carried it. A genetic or accumulative

Jan 1, 1931

By D. J. McAdam, G. W. Geil, D. H. Woodard, W. D. Jenkins

INTRODUCTION IN a series of papers, the authors and their associates have shown the influence of four important factors on the technical cohesion limit.3-16 By "technical cohesion limit" is meant the technically determinable resistance to fracture. The four important factors are the stress system, plastic deformation, temperature, and the strain rate. The influence of any one of these factors may be represented by a curve of cohesion limits, although only one point on the curve may represent actual fracture. As the term "fracture stress" has come into general use with the same significance as technical cohesion limit, the authors are here using the shorter term with the understanding that it does not always refer to actual fracture. The previously-mentioned series of papers contains ample evidence that plastic extension increases the fracture stress of any polycrystalline metal. In a recent paper of the series,15 moreover, it has been shown that the effect of plastic deformation on the fracture stress cannot be attributed to reorientation of internal flaws but is a work-strengthening effect, similar to the effect on the flow stress.[$] Plastic deformation of steels, however, may not only cause work hardening, but may result in additional hardness because of strain aging. Some evidence that strain aging affects not only the flow stress but also the fracture stress, has been presented in a recent paper.14 In that paper, a study is made of the influence of plastic deformation at room temperature on the fracture stress of ferritic steels at -188°C. The study is based on the results of two-stage tests. In the first stage each specimen was extended a predetermined amount at room temperature; in the second stage the specimen was tested to fracture in liquid air. In most of these tests the specimen remained in the testing machine during the interval of about one hour between the first and second stages, it was kept under a tensile load of about 500 lb and maintained at liquid air temperature. The effects of various amounts of plastic deformation on the fracture stress were thus determined and curves were obtained to represent the influence of plastic deformation at room temperature on the stress at brittle fracture in liquid air.14 Two specimens of ingot iron, however, were removed from the testing machine at the end of the first stage and several days elapsed before the specimens were tested to fracture in liquid air. As shown in Fig 8 of that paper," the points representing fracture of these specimens are far above the curve representing the results of two-stage tests without a rest interval between the stages. The evidence thus indicated that the fracture stresses of these two specimens were increased not only by the work-strengthening, but also by strain aging. The present paper presents results of further investigation of the influence of strain aging on the fracture stress. There are two kinds of aging of steel.

Jan 1, 1948

By P. D. Merica, J. R. Freeman, R. G. Waltenberg

Contents Page Constitution of Commercial Aluminum.................. 4 Solubility of CuAl2 in Aluminum at Different Temperatures........ 9 Effect of Magnesium on Solubility of CuA12 in Aluminum ......... 15 Solubility of Mg4Al8 in Aluminum at Different Temperatures........ 15 Solubility of Metals and Metal Compounds in Aluminum.......... 20 Summary and Conclusions......................20 Aluminum and its alloys have been the subject of much investigation1 during recent years, in the course of which the principal features of the constitution of most of the binary alloy systems with aluminum have been determined. Except in the case of a few metals—silicon, bismuth, cadmium, lead, zinc, and tin—an aluminum-rich compound is formed in each binary system, which forms a eutectic with the aluminum or its solid solution with this compound: Thus such compounds as FeAla, CuA12, Mg4Al3, and NiAls are formed, which are found in aluminum-rich alloys of their respective series as eutectics with the aluminum solid solution. These compounds are, in all cases, hard and brittle and their presence affects profoundly the physical properties of the alloys in which they occur. Within the zinc-aluminum system a compound, Al2Zn,, is formed that decomposes at lower temperatures. Silicon and tin each form a simple eutectiferous series with aluminum; bismuth, lead, and cadmium are only partly miscible in the liquid state with it. The extent of the solubility in aluminum, in solid solution, of these compounds or of the elements themselves, in the case of those series in which compounds are not formed, is of the greatest importance in

Jan 1, 1921

By J. H. Wernick, E. E. Thomas

THE etch-pit technique for revealing dislocations in bulk samples allows one to determine dislocation densities and to study their behavior under various mechanical and thermal treatments. We have developed a chemical polish-etch for the development of etch pits on the (1100) plane of Cd which appear to

Jan 1, 1961

By Brahm Prakash, R. Schuhmann

Chemical conditions for flotation and nonflotation of cassiterite and fluorite with oleic acid as collector and with alizarin dyes as modifying agents were studied by means of small-scale, vacuum-flotation tests. Artificial cassiterite was prepared for these tests by high-temperature methods, especially by crystallization from borax melts.

Jan 5, 1950