Search Documents

The opening session of the Institute was held at the rooms of the American Society of Civil Engineers, No. 4 East 23d Street, VicePresident R. W. Raymond in the chair. After a short introductory address by the chairman, the following names were presented by the Council for election as members and associates of the Institute. They were unanimously elected : MEMBERS. Abbott, James W.,.....Lake City, Col. Abbott, J. J., Jr.,...... Lake City, Col. Bartlett, J. C.,.....Cambridge, Mass. Billings, G. H.,.....Boston, Mass. Blake, Frank C.,.....Lafayette College, Easton, Pa. Dewey, Fred. P.,.....Lafayette College, Easton, Pa. Douglass, Samuel T.,. .. . Ann Arbor, Mich. Emmons, 9. F.,.....New York City. Engle, George U.,.....Philadelphia. Harrington, Dr. Bernard J.,. .. Montreal, Canada. Hayden, Wm. B.,.....Columbus, O. Hill, Leslie C.,.....Capelton, Quebec, Canada. Land, W. J.,......Atlanta, Ga. May, Wm. A.,.....Scranton, Pa. Mills, James E.,.....St. Louis, Mo. Moore, Charles W.,.... Montezuma, Ind. Page, William Byrd,.... Lexington, Ky. Putnam, Douglas, Jr.,.... Ashland, Ky. Richards, Henry,.....Dover, N. J. Boberts, Percival, Jr.,. .. . Philadelphia. Sackett, S. G.,......Brooklyn, N. Y. Schley, Wm. S.,.....Atlanta, Ga. Setz, Gustav,......Mine La Motte, Mo. Talhutt, John H.,.....Lexington, Ky. Torrey, Herbert G.,.... U. S. Assay Office, New York City. Wernlitz, Fred. W.,..., Cartersville, Bartow Co., Ga. Wiestling, Geo. B.,.....Mont Alto, Franklin Go., Pa.

By L. J. Health

Synthetic rock with predictable porosity and permeability has been Prepared from mixtures of sand, cement and water. Three series of mixes were investigated primarily for the relation between porosity and permeability for certain grain sizes and proportions. Synthetic rock prepared of 65 per cent large grains, 27 per cent small grains and 8 per cent Portland cement, gave measurable results ranging in porosity from 22.5 to 40 per cent and in permeability from 0.1 darcies to 6 darcies. This variation in porosity and permeability was caused by varying the amount of blending water. Drainage-cycle relative permeability characteristics of the synthetic rock were similar to those of natural reservoir rock. INTRODUCTION The fundamental behavior characteristics of fluids flowing through porous media have been described in the literature. Practical application of these flow characteristics to field conditions is too complicated except where assumptions are overly simplified. The use of dimensionally scaled models to simulate oil reservoirs has been described in the literature. 1-3 These and other papers have presented the theoretical and experimental justification for model design. Others have presented elements of model construction and their operation. In most investigations the porous media have consisted of either u ncon soli da ted sand, glass beads, broken glass or plastic-impregnated granular substances—materials in which the flow behavior is not identical to that in natural reservoir rock. The relative permeability curves for unconsoli-dated sands differ from those for consolidated sandstone. The effect of saturation history on relative permeability measurements is discussed by Geffen, et a1.4 Wyga15 has shown quite conclusively that a process of artificial cementation can be used to render un consolidated packs into synthetic sandstones having properties similar to those of natural rock. Many theoretical and experimental studies have been made in attempts to determine the structure and properties of unconsolidated sand, the most notable being by Naar and Wygal.6 Others have theorized and experimented with the fundamental characteristics of reservoir rocks. This study was conducted to determine if some general relationship could be established between the size of sand grains and the porosity and permeability in consolidated binary packs. This paper presents the results obtained by changing some of the factors which affect the porosity and permeability of synthetically prepared sandstone. In addition, drainage relative permeability curves are presented. EXPERIMENTAL PROCEDURE Mixtures of Portland cement with water and aggregate generally are designed to have certain characteristics, but essentially all are planned to be impervious to water or other liquids. Synthetic sandstone simulating oil reservoir rock, however, must be designed to have a given permeability (sometimes several darcies), a porosity which is primarily the effective porosity but quantitatively similar to natural rock, and other characteristics comparable to reservoir rock, such as wettability, pore geometry, tortuosity, etc. Unconsolidated ternary mixtures of spheres gave both a theoretically computed and an experimentally observed minimum porosity of about 25 per cent.7 By using a particle-distribution system, one-size particle packs had reproducible porosities in the reproducible range of 35 to 37 per cent.6 For model reservoir studies of the prototype system, a synthetic rock having a porosity of 25 per cent or less and a permeability of 2 darcies was required. The rock had to be uniform and competent enough to handle. Synthetic sandstone cores were prepared utilizing the technique developed by Wygal.5 Some slight variations in the procedure were incorporated. The sand was sieved through U. S. Standard sieves. A 18-20 sand denotes that the sand passed the Number

Jan 1, 1966

By R. C. Neavel

One of the most important requirements to be met by any coal producer is delivery of size consists tailored to specific applications. Generally these specifications include a minimum as well as a maximum size limit. The customers of a major Indiana coal producer noticed that some shipments of sized coal contained a large proportion of undersize pieces. Also, in these shipments, the pieces which remained within the specified limits were cracked and, when handled, crumbled readily. The producer, certain that these shipments had been properly sized at the tipple, suspected that degradation had occurred in transit. The Indiana Geological Survey was requested to examine the coal from one of these shipments to attempt to determine the cause of breakage. Two basic facts about coal and coal seams led to the employment of petrographic techniques in this investigation. First, all coal seams consist of accumulations of diverse organic and inorganic constituents; and second, most coal breakage, either desirable or undesirable, can be attributed to the inherent weakness of some of these constituents or to poor adhesion between certain constituents. Analyses of degraded coal Sampling: Samples were secured from 2 stock piles of 2-by 4-inch coal in a dealer's yard. The coal in both piles had received the same treatment from mining to storage, although it had been mined and shipped on two different days. The size consist of one pile, however, appeared smaller than that of the other. The sample from the degraded pile is referred to as the slack sample, and the other is called the unslack sample. Size analyses: In order to determine the actual size consist, the samples were screened, with a minimum of rough handling, on square 2-inch, 1-inch, 1/2-inch, and 12-mesh screens. It is assumed that 100 percent of the 2-by 4-inch coal is retained on a 2-inch round screen at the tipple. Analyses of several loads at the tipple indicate that approximately 26 percent of the 2- by 4-inch coal, 100 percent of which was assumed held on a 2-inch round screen, passed through a 2-inch square screen. Twenty-six percent may be taken as the normal difference between round and square screens. Results of the analyses of stockpile coal are shown in Table 1. Cumulative percent versus size are plotted on a Rosin-Rammler chart as Figure 1. Both samples approximately follow normal size distribution; this indicates that breakage is not size preferential and also that the samples are representative of the stockpiles. Although both samples exhibit the same general size distribution, the median size of the slack sample is considerably smaller than that of the unslack sample. Fifty-five percent of the unslack sample was undersize (29 percent greater than the normal 26 percent difference), and 83 percent of the slack sample was undersize (57 percent greater than the normal 26 percent difference). Both piles contained a greater percentage than normal of undersize coal; this indicates that they were both affected by degradation, but to a different degree. Bedding-plane analyses: Coal, because of its laminated nature, will break preferentially along bedding planes, especially where adjacent constituents are poorly cemented to each other. Subsequent breakage perpendicular to the

Jan 1, 1961

By K. P. Fournier

This report describes work on the problem of predicting oil recovery from a reservoir into which water is injected at a temperature higher than the reservoir temperature, taking into account effects of vis cosity-ratio reduction, heat loss and thermal expansion. It includes the derivation of the equations involved, the finite difference equations used to solve the partial differential equation which models the system, and the results obtained using the IBM 1620 and 7090-1401 computers. Figures and tables show present results of this study of recovery as a function of reservoir thickness and injection rate. For a possible reservoir hot water flood in which 1,000 BWPD at 250F are injected, an additional 5 per cent recovery of oil in place in a swept 1,000-ft-radius reservoir is predicted after injection of one pore volume of water. INTRODUCTION The problem of predicting oil recovery from the injection of hot water has been discussed by several researchers. l-6,19 In no case has the problem of predicting heat losses been rigorously incorporated into the recovery and displacement calculation problem. Willman et al. describe an approximate method of such treatment. 1 The calculation of heat losses in a reservoir and the corresponding temperature distribution while injecting a hot fluid has been attempted by several authors.7'8 In this report a method is presented to numerically predict the oil displacement by hot water in a radial system, taking into account the heat losses to adjacent strata, changes in viscosity ratio with temperature and the thermal-expansion effect for both oil and water. DERIVATION OF BASIC EQUATIONS We start with the familiar Buckley-Leverettg equation for a radial system:* This is sometimes referred to as the Lagrangian form of the displacement equation. If the injection water is at some temperature Ti which is above reservoir temperature TR, then lw, the flowing fraction which is water, is a function of both water saturation and fluid temperature at any given time and position in the reservoir. The temperature dependence of lw results from the temperature dependence of the viscosity ratio µo/µm of which lw is a function. Thus:

Jan 1, 1966

By T. K. Perkins, L. R. Kern, R. E. Wyant

Many factors influence the results of hydraulic fracturing to stimulate well productivity. Most of these factors have been studied and their effects discussed in the literature. However, the movement of sand through the crack during fracturing has received little consideration. Exactly where the sand goes in the fracture, how it gets there, and how this might influence results have not been studied, judging from published reports. To get an answer to some of these questions we have studied sand movement through a simulated crack segment in the laboratory. Although the work is preliminary, we have answered some questions about sand movement in a semiquantitative sense. We are reporting our results at this time in the hope of stimulating interest and further study in this important aspect of fracturing. LABORATORY EXPERIMENTS Fig. 1 is a schematic diagram of equipment used in this study. A segment of a vertical crack 0.25-in. wide was formed between two Plexiglas plates, and movement of sand in fluid through the crack was observed under various conditions. Sand and fluid were injected into the crack at constant rates. The top and bottom of the crack were closed so that the fluid flowed horizontally. Because of gravity most of the sand settled to the bottom before moving very far through the crack. If the fluid velocity exceeded a certain critical value, then all the sand injected was washed on through the crack even though it had settled to the bottom. When the fluid velocity was less than this value when sand injection was started, most of the sand which settled in the crack remained in place until enough of the area open to fluid flow was blocked by the settled sand to increase the fluid velocity to the critical value.. At this point all injected sand moved on through the crack even though it settled to the lower portion of the moving fluid section. All sand previously settled remained in place. When fluid velocity was increased at this paint by increasing fluid injection rate (without also increasing sand injection rate), some of the previously settled sand was washed out until enough area was open to flow that the velocity dropped to the critical value. Conversely, when the fluid velocity was decreased by decreasing the fluid injection rate (without changing the rate of sand injection), additional sand would settle until the critical velocity was again attained. In short, the critical velocity is an equilibrium value which the system will automatically seek, if possible. The equilibrium (or critical) velocity was measured under several conditions. The results of these measurements are shown in Pig. 2 where the equilibrium velocity is shown as a function of the amount of sand injected per minute. The points falling in the shaded band shown in Fig. 2 were obtained with water. The higher viscosities were obtained by adding CMC (carboxymethylcellu-lose). Data indicate that the equilibrium velocity is not very sensitive to sand size or transport fluid viscosity, or to sand injection rate (except at very low rates). Points connected by the solid CUrve in Fig. 2 were obtained with water and 20- to 40-mesh steel shot. The equilibrium velocity is apparently fairly sensitive to difference in density between particle and fluid. Only one run was made with a gelled fluid and that was gelled water at zero sand injection rate as shown in Fig. 2. (Measurements of equilibrium velocity at zero sand injection rate were made by filling the crack

By S. H. Ward

Since the advent of the first airborne electromagnetic system, it has been evident that such systems were inherently limited to shallow depths of exploration of the orderof 100 to 200 feet. Hence in 1948 the author and his associates commenced a study of the feasibility of applying natural audio frequency magnetic fields to investigation of the electrical properties of the subsurface in order to provide a system capable of overcoming this limitation. This research culminated, in the summer of 1958, in the development of a new airborne prospecting device — AFMAG. This device has detected surface massive sulphide bodies while flown at heights as great as 3000 feet. Hence, by inference, it is deduced that it could find similar sulphide bodies if they were buried 2500 feet below surface and the aircraft flown at 500 feet. Thus a considerable improvement over conventional airborne electro-magnetic systems is obtainable with AFMAG. Airborne exploration in mountainous terrain involving deep valley fill now becomes possible. Examples are presented of the results of actual airborne AFMAG test surveys over known deposits of massive sulphide mineralization. Interpretation of the data is discussed with particular reference to the knowledge of size, dip, depth, depth extent, and conductivity of causative bodies as deduced from the flight records. The possibility of mapping major geologic structures, for both mining and oil exploration purposes, is discussed with the aid of examples of airborne AFMAG data. INTRODUCTION Electrical prospecting with natural audio frequency electromagnetic waves as a source has, within the last three years, become a practical reality. Both airborne and ground survey instruments under the trademark "AFMAG" (for audio frequency magnetics) have been used successfully in the search for conductive mineral deposits. It is the object of this paper to discuss the principles of airborne AFMAG and to illustrate its application by means of examples obtained over known geological situations. WHY AFMAG? In view of the large number of good airborne electromagnetic systems available for purchase or contract surveying, one may well ask, "Why another new system?". Primarily the answer lies in the fact that AFMAG does not suffer from the very limited depth of exploration available with, and inherent in, any conventional airborne electromagnetic system. AFMAG is not conventional insofar as an artificial transmitter is not required. Only a receiving and detecting device is employed. The electromagnetic fields measured are those from millions of electrical discharges in the atmosphere (e.g;..- lightning strokes). Their random distribution in time and space make these fields difficult to employ and it is only with recent advances in the electronics of geophysical instrumentation that this has become possible. A second reason for AFMAG and one of its

Jan 1, 1961

Jan 1, 1929

By K. E. Merklin, F. D. DeVaney

Students of the modern blast furnace seem unanimously agreed that they are observing a major revolution in practice. Rather than changing construction and operation of the furnaces, most of the great advances now under way deal with the raw materials feed. Prepared burdens have gained increasing significance during recent years. Sizing, concentration, and agglomeration have all become bywords to greater production and reduced operating costs. The remarkable results with test furnaces in which self-fluxing sinter makes up part or all of the ore charge foretell even greater improvements. Other investigators have reported many of these advances, and it is enough to predict here that more and more operators will turn to the use of self-fluxing sinter. This change in the operator's requirements comes at a time when one major section of the iron ore regions, the Mesabi, is finding it difficult to maintain, let alone improve, the tonnage and grade of its shipping product. To meet the new demands with respect to quality and structure, the iron ore producers of this area turned first to screening, crushing, and concentrating intermediate ores. More recently, declining higher-grade reserves have led to multimillion-dollar investments in plants to treat the low-grade magnetic taconites.1,2 To yield a suitable concentrate, the Minnesota magnetic taconites must be ground to about 80 pct through 325 mesh, too fine to be charged directly to the blast furnace or to make acceptable feed to the sinter strand. The pelletizing process was developed to meet the structure requirements laid down by the blast furnace operators. Taconite producers are succeeding in their efforts just when the attention of the blast furnace man is being drawn to the great advantages of self-fluxing sinter.3 The taconite operators are ready with an alternative. Why not produce sclf-flus ing pellets? At the Hibbing laboratory of Pickands Mather & Co., where much of the early work was done that led to Erie Mining's 7.5-million ton taconite plant at Hoyt Lakes, Minn., preliminary investigations have been made. Present Taconite Operations: Details of this work will be clarified by a brief review of agglomeration practice in commercial taconite plants. After the taconite has been ground to about 80 pct through 325 mesh to liberate the magnetite grains, the ore is concentrated on magnetic separators, thickened, and filtered to about 10 pct moisture. This structure and moisture fit in closely with the conditions required to produce good balls. It has been found with taconite concentrates that at least 60 pct of the feed to the balling drum must be —325 mesh to obtain good ball compaction within reasonable time. The filter cake moisture usually permits a slight water addition at the balling drum, and further balling control is obtained by adding about 12 Ib of bentonite and 1 1/2 lb of soda ash per dry short ton of concentrate. These additives, and occasionally small quantities of fine coal, are thoroughly mixed with the filter cake ahead of balling. The swelling property of bentonite improves the green and dry strength of the balls so they can be handled without breakage until they are fired. Soda ash is added for pH control to insure maximum performance of the bentonite, and coal is added for more heat in the firing process when required. The balls, normally 3/8 to l-in. diam, are brought to a temperature of 2350" to 2500°F in the indurating furnace. Heat for this process comes from three sources: 1) fuel burned in the combustion chamber, 2) oxidation of the magnetite concentrates to hematite, and 3) coal added to the balls. Pellet strength is developed by grain growth and bridging and, if enough slag-forming constituents are present, by slag bonding. Conversion to hematite is usually close to 100 pct in the fired pellets. Batch Test Procedures: Initial studies of self-fluxing pellets were made by producing balls on a batch basis under carefully controlled laboratory conditions. The l-in. balls, uniform in size, were fired in an oxidizing atmosphere in a standard laboratory muffle furnace. The firing procedure consisted of

Jan 1, 1961

By C. H. Mathewson

MY treatment of the subject of "Metals of the Future" is imaginative rather than statistical or scientific, because reliable information concerning useful concentrations in the form of ore deposits of by far the majority of the elements does not exist and the chemical, physical, and mechanical properties of the unfamiliar metals are recorded only in fragmentary and uncertain form or not at all.

Jan 1, 1944

By Scott, Turner

MY whole life has been spent in the mining business, PO I naturally tend to address my remarks particularly to the newly-graduated mining and metallurgical engineers among you. To a certain extent, all forms of engineering principles are involved in the training of the mining engineer, and most sorts of engineering are certainly utilized by him, so every one of this graduatins class is concerned with the field I propose to discuss.

Jan 1, 1932

THE purpose of this chapter is to present a general outline of the basic open-hearth process for the benefit of students, practicing open-hearth operators, and metallurgists who wish to review the subject. The discussion is limited to a description of the sequence and purpose of the operations, illustrated by data and examples. Subsequent chapters deal with more detailed and fundamental studies of the subject. The function of the basic open-hearth furnace is to convert various types of ferrous material into finished steel of given com- position and quality. In comparison with other steelmaking methods, the basic open-hearth process is one of the most versa- tile, both from the standpoint of the raw materials that can be used and the types of steel that can be produced. The process can be considered as a sequence involving melting, refining, and deoxidation. With some types of liquid-metal charges, the melting stage is not present, but refining and deoxidation in varying degrees are fundamental features of the process. GENERAL DISCUSSION OF BASIC OPEN-HEARTH PROCESS The first consideration in open-hearth practice is the type of charge on which the operation is based. This consists of three components-fluxing, oxidizing, and metallic materials. Fluxes. In the basic process the fluxing material is primarily lime, added in the form of either limestone (CaC03) or burnt lime (CaO) . This is supplemented by magnesia (MgO) and lime from the furnace bottom and banks. The function of these fluxes is to form a slag with the silica (SiO2) , manganese oxide (MnO), iron oxides (FeO and Fe203), and phosphorus oxide (P205) that are produced by the oxidation of varying amounts of the silicon, manganese, iron, and phosphorus in the charge during melting and refining. The slag, composed of the basic fluxes and the neutral and acid oxides, floats on top of the steel bath when the charge is melted. The composition of this slag depends on the amount of each slag-forming element present in the charge and on the extent of oxidation of these elements during the course

Jan 1, 1964

By AIME AIME

American Institute of Mining Engineers. (Organized in 1871, and Incorporated in 1905.) OFFICERS. For the year ending February, 1906. Directors JAMES GAYLEY (President), R. W. RAYMOND (Secretary), FRANK LYMAN Treasurer). T. A. RICKARD NEW YORK, N. Y. CHARLES H. SNOW NEW YORK, N. Y. R. W. RAYMOND NEW YORK, N. Y. (Terms expire February, 1906.) JAMES GAYLEY NEW YORK, N. Y. FRANK KLEPETKO NEW YORK, N. Y. FRANK LYMAN NEW YORK, N. Y. (Terms expire February, 1907.) JAMES DOUGLAS NEW YORK, N. Y. JAMES F. KEMP NEW YORK, N. Y. ALBERT R. LEDOUX NEW YORK, N. Y. (Terms expire February, 1908.)

Jan 1, 1906

By H. F. Seifert

THE classification and preparation of non-ferrous scrap metals is a subject of interest to every individual and corporation that employs in its processes of manufacture non-ferrous metals and alloys and accumulates in such manufacture scrap from these materials for disposition in the form .of turnings, borings, short ends, punchings, clippings, grindings, washings, etc. All too frequently the disposition-of such scrap is left to individuals who have no knowledge of the subject either from a metallurgical or a commercial standpoint, or both. Much money is thus lost which with a little more intelligent effort might be saved, and in this day of fierce competition and small profits such an opportunity cannot be ignored. The Mineral Resources of the United States for the year 1925, the latest issue available (Part 1, page 221), gives the secondary non-ferrous TABLE 1.-Some. Secondary Non-ferrous Metals Recovered in the United States for the -Year 1924-25 Material Short Tons Value Copper, including that in alloys other than brass.... 250,600 8 71,170,400 Brass, scrap remelted : 242,300 56,270,800 Lead as metal : 112,420 39,477,100 Lead as alloys 112,460 Zinc as metal 61,430 11,359,000 Zinc in alloys other than brass 13,300 Tin as metal 7,950 Tin in alloys 23,000, 35,165,400 Antimony as metal 1 3,794,000 Antimony in alloys : 10,839 Aluminum as metal 17,700 24,816,000 Aluminum in alloys 26,300 Nickel as metal 191 1,518,000 Nickel in non-ferrous alloys 2,109 Total l 882,600 $243,570,700

Jan 1, 1928

By R. J. Mechin

TOP-SLICING was introduced in the Pachuca district in 1917 by T. C. Baker, at that time mine superintendent, of the Santa Gertrudis mine. There then existed 1200 ft. (365.7 m.) below the surface, lying between the fourteenth and eighteenth levels (a vertical distance of 108 meters) a block of ore having a length of 295 ft. (90 m.), and an average width of 82 ft. (25 m.) and dipping at an angle of 65°. This block lay in the hanging wall of the vein and consisted of highly altered and fractured andesite, cut through with mineralized quartz stringers. On the foot-wall side, 26 ft. (8 m.) of old filling, left by former operators, was of payable grade. Stoping therein was first undertaken by the square-set filling system, but because of the extremely heavy hanging wall and loose dry filling in the foot wall, all square setting had to be accompanied by spiling, which made the operation exceedingly slow and costly. A system of mining was sought that would eliminate the difficulties inherent to the square-set system in heavy ground and that at the same time would effect the desired economies in mining. After several years, top-slicing has met all the conditions most satisfactorily, so that when similar conditions presented themselves in El Bordo mine, this method was adopted with necessary modifications. El Bordo mine is operated by the Santa Gertrudis company, and is situated about two miles north of Pachuca. Because of the diversity of the orebodies, a number of different mining methods are in use, among them top-slicing.

Jan 10, 1925

By T. S. Lundy, J. Askill

J. Askill and T. S. Lundy (Oak Ridge National Laboratory)—Moore has proposed a simple correlation between the activation energy for solute diffusion in fee metals and the atomic volume of the diffusing species using both tracer and chemical-diffusion data. The first point we wish to make is that it is wrong to attempt such correlations without separating the two types of data. Activation energies obtained using tracer techniques cannot, in general, be directly compared with those obtained from chemical-diffusion experiments. A knowledge of the variations of chemical potentials with composition is necessary and chemical-diffusion data must be corrected for such variations, even for dilute alloys, before a comparison is possible. Secondly, for nickel, iron, aluminum, and lead, Moore neglected a number of recently published works, e.g., Al26 and Mn54 in aluminum,46 cr51 in nickel,47 and Fe55 in iron.48 These and others should have been used. If one considers only the tracer diffusion data, there is left no simple correlation of the type proposed by Moore. For example, in the case of solute diffusion in aluminum the only reliable tracer data listed by Moore are for zinc and aluminum. The nickel, cobalt, and iron data of Agarwala49 are representative of near-surface diffusion-not bulk diffusion. In conclusion we suggest that for tracer diffusion data in these fee metals there is no justification for proposing any simple correlation of activation energy with atomic volume using the limited data that are presently available. R. H. Moore (author's reply)—The writer has proposed a simple correlation which is useful in estimating the internal consistency of diffusion data. The accuracy of the correlation is, of course, a function of the number of data available. Lundy and Askill take issue with the writer's decision to include data for the systems: nickel, iron, aluminum, and lead, taking the view that the data are insufficient to establish the correlation. The writer agrees that the data are insufficient and has cau- tioned the reader that the correlation is tentative in these instances. Inclusion of these systems is justified by the interesting trends the correlation reveals. For example, the distinction between interstitial and substitutional diffusion may be clearly established, Figs. 4 and 6, and the behavior of transition elements and nontransition elements is indicated to parallel the behavior illustrated by the silver and copper systems. Lundy and Askill have singled out the aluminum system for special criticism. The writer chose to discuss the data for diffusion of iron, nickel, and cobalt in aluminum in the terms used by the original authors9 and has included the comments of Balluffi.l0 The writer did not intend the reader to conclude that data for these elements should correlate with data for the nontransition elements as Lundy and Askill have evidently assumed. Iron, nickel, and cobalt form intermetallic compounds with aluminum, so the activity coefficients of these elements may be expected to deviate markedly from unity. This may account for the low frequency factors observed by Hirano.9 The nontransition elements, on the other hand, yield relatively simple phase diagrams with no evidence for intermetallic compound formation as in the case of iron, nickel, and cobalt. In dilute solution, Henry's law should be closely obeyed, the activity coefficients should not deviate markedly from unity, and the effect on the activation energy should not be large. The accuracy of the correlation applied to these systems will improve as the data is extended. It does not seem unreasonable to conclude that its extension should be encouraged.

Jan 1, 1965

By G. F. Butterworth

The metallographic structures most frequently encountered in rifle barrels, and which are illustrated by the accompanying photomicrographs, fall naturally into two groups, distinguished by the method used to, produce in the stock a physical condition having the requisite properties. The fist group consists of "rolled" barrels; that is, barrels subjected to hot working by rolling in or near the critical range. In the second group, the stock, which is smaller in diameter than the first, is upset to form the butt end and is then heat treated by giving it a quench and a draw. These barrels will be referred to as " heat-treated " barrels. The structure of the rolled barrels resembles closely that of the same steel after annealing. There is the same network of excess ferrite outlining the grain boundaries, but the grains themselves are composed of sorbite rather than pearlite. The grain size is closely related to the rolling temperature. The critical-point curves of this grade of steel, which is approximately 0.50 to 0.60 per cent. of carbon and 1.00 to 1.30 per cent, of manganese, show a single very pronounced point between 1300" and 1350" F. (704" and 732" C.). Barrels rolled within this temperature range give an exceedingly fine grain, shown in Fig. 1. In fact, the grains may be so fine that, at a low magnification, they may be confused with the heat-treated structure shown in Fig. 6. A magnification of 500 diameters, however, will always resolve a rolled barrel into the characteristic structure shown in Fig. 2. As the temperature is increased, the grains are found to be larger. If, on the other hand, the rolling temperature is below the critical range, the structure previous to rolling will not be obliterated, the only effect of rolling being to elongate the coarse sorbite grains in the direction of rolling, Fig. 3. This distortion is greatest at the muzzle. Heat-treated barrels are quenched in oil from above the critical range, which should give a martensitic structure, Fig. 4, but the presence of some troostite in the martensite is frequently noted when the quench has not been sufficiently drastic, Fig. 5. The structure brought about by the subsequent draw is not so striking, though quite as typical. It is sorbitic or sorbito-pearlitic, and under a low magnification appears almost homogeneous, as in the case of fine grains of pepper and salt well mixed together, Fig. 6. This structure is substantially the same for all

Jan 1, 1920

By J. H. Brophy, M. H. Kamdar, J. Wulff

A constitutional diagram for the Ta-W-Re alloy system is presented. Rhenium dissolves in the complete range of solid solutions between tungsten and tantalum up to 48 wt pct in tantalum 'to about 30 wt pct in tungsten. Intermediate x and u phases only are found. X-ray diffraction and fluorescence, metallography and melting-point measurements were employed. THE constitution diagram of ternary alloys of tungsten, tantalum, and rhenium for temperatures above 1000°C is reported in this paper. Alloys in this system rich in tantalum and tungsten are of interest for high-temperature applications, and those rich in rhenium for electronic applications. No ternary phase diagram appears to be available in the literature. The three-component binary diagrams have been previously established1-3 and the present ternary data are consistent with these. EXPERIMENTAL TECHNIQUES Commercially pure tantalum (99.7 pct), rhenium (99.99 pet), and tungsten (99.9 or 99.95 pct) powders were purchased from Fansteel Metallurgical Corp., Chase Brass and Copper Co., and Fansteel or Westinghouse Electric Corp., respectively. These powders were pressed without binder and arc-melted under helium. The preparatory and analytical techniques employed were identical to those used for the Ta-Re system investigation carried out in this laboratory.324 These included X-ray diffraction and metallographic phase identification, X-ray fluorescent and wet chemical analyses, solidus determinations and heat treatments in a resistance-heated tantalum-filament vacuum furnace. For microstructural examinations standard mechanical polishing techniques were used through diamond laps. Polished speciments of all compositions were etched by swabbing with 4 parts HI?, 4 parts HNO3, and 1 part H20. Since the microstruc-tures of alloys containing one or two phases closely resembled their counterparts in the respective binary systems, typical examples are omitted in this presentation. In all the alloys examined, it was possible to observe the number of phases present. Particularly when there were small amounts of one phase involved, it was possible to identify it only by a combined conclusion based on X-ray diffraction, position of an alloy in a composition series, and the phase rule. A total of 100 different alloy compositions was arc-melted and studied in the as-cast condition metallographically and by X-ray diffraction. Specimens of each of these compositions were heat-treated at 2680, 2530, and 2020°C for 1, 2, and 4 hr, respectively. Those which were treated at 2020 were given a preliminary homogenization treatment at 2500°C for 1 hr. Specimens of 25 alloys were heat-treated at 1200o C for 168 hr. Solidus temperature measurements were made by the detection of incipient melting in eighteen alloy compositions. The metallographic and X-ray diffraction results are summarized in Table I. Graphically, this information appears in the isothermal plots of Figs. 2 and 3. Within the accuracy of the experimental methods, two such plots are sufficient to locate these data, since the results for 1200°C were similar to 2020 and those at 2530 resembled 2680

Jan 1, 1962

By H. E. Cline

Solidification of Pb-Sn alloys ranging in composition from 1.2 to 56 at. pct Pb ws observed with polarized light. Lamellar structures were observed over a larger range of compositions in alloys containing excess tin than excess lead, as expected from constitutional supercooling. The occurrence of pools of supercooled liquid surrounded by lead is explained by the difficulty in nucleating tin. Cells and dendrites weve observed in tin-rich alloys. Evidence was found that the degenerate structure formed at low growth rates, the formation of faults, and abrupt changes in composition and structure can be attributed to non-steady-state growth. The apparent interface shape was observed to have deep grooves at the interphase boundaries. HUNT and Jackson have observed the shape of the interface during growth of organic eutectics. They observed the formation of lamellar faults and shape instabilities upon changes in growth rate. The lamellar structure in these organic eutectics was not restricted to the eutectic composition. Recent work by Mollard and Flemings2 indicated that Pb-Sn alloys from 12 to 26 at. pct Pb could be solidified with a lamellar or rodlike structure if a sufficiently steep temperature gradient was used at a slow growth rate. Observations of the solid liquid interface of the Pb-Sn eutectic were made by Davies3 using polarized light. Photographs were at too low a magnification to determine the interface shape, but he has concluded that tin was the leading phase. In the following experiments, solidification of a range of Pb-Sn alloys from 1.2 to 56 at. pct Pb was observed using polarized light, to determine the factors controlling stability of the lamellar structure. EXPERIMENTAL Procedure. One hundred-gram ingots of alloys prepared from 99.999 pct pure Pb and Sn were cast into graphite molds under argon. The compositions of the alloys were 1.2, 6, 12, 26, 36, 46, and 56 at. pct Pb. Two-gram pieces were melted between two cover glass slides which were squeezed into a 1-mm separation. Samples were then observed under polarized light in a hot stage shown in Fig. 1. A long working distance objective designed for viewing at 500 times was used. Photography was made difficult by the lack of illumination and contrast at these high magnifications. By using an elliptical polarization compensator, as suggested by A. Holik, the contrast and illumination could be optimized. Photographs could be taken only at slow growth rates to avoid excessive interface motion during the 15-sec exposure used. The solidification rate was varied by increasing or decreasing the power to the heater. It was found that insulation was necessary to avoid undesired growth rate fluctuations. The temperature gradient, as measured with two thermocouples 1 cm apart, was 80" ± 20°C per cm during all the experiments reported here. The advantage of this procedure is in being able to observe solidification while it is occurring. However, the observations are restricted to the glass-metal surface and may be influenced by this surface. Also, one has no knowledge of the interior of the sample, in contrast to studies of the freezing of transparent organic eutectics.' Observations. The alloy near the eutectic composition (26 at. pct Pb) solidified in a lamellar structure when the growth rate was uniform. If the growth

Jan 1, 1968

By AIME AIME

T HE Institute of Metals Division and the Iron and Steel Division will meet jointly at the Stevens Hotel, Chicago, during the week of the American Metals Congress, Sept. 22-26. The Iron and Steel Di- vision of the American Society of Mechanical Engineers, the American Society for Steel Treating and the American Welding Society meet at the same time. but the sessions have been arranged to conflict as little as possible. A rich program of papers and plant visits has been arranged for the members and guests of the two Institute Divisions. The annual dinner and a pro- gram of entertainment are being arranged by the Woman's Auxiliary of the Chicago Section. Members are urged to register immediately up011 arrival and to make dinner and plant visit reservations at the same time.

Jan 1, 1930

By D. Kunstelj, M. Stubicar, A. Tonejc, A. Bonefacic

A. Bonefafcic, D. Kunsfeli, M. Stubicar, and A. Tonejc The present communication is concerned with the variation of the texture in aluminum wires with die angle and temperature, at constant speed of extrusion. Experiments were carried out concurrently on refined samples, with a stated purity of 99.997 pct pure A1 and commercial samples of 99.5 pct Al. Ingots of refined aluminum samples were machined to 30-mm-diam by 150-mm-long billets. These billets were transformed to 5-mm-diam wires by drawing. The final form, suitable for examination, was obtained by extrusion through conical-face dies with a 1-mm hole diam and extrusion ratio 5:l in diam. The initial form of the commercial aluminum samples was drawn wire 5 mm in diam. These samples showed a poorly defined texture with (111) as a major and (001) as a minor component. A similar defined texture appeared in the refined aluminum samples after drawing to 5 mm diam. Conical-face dies with different angles (defined by the axis and the generating line of the cone) were used in our experiments. The values of the angles were 27, 35, 45, 57, 63, and 90 deg. The extrusion container was fitted with a heating element and controller permitting temperatures up to 600°C to be maintained within i5"C. Extrusion was performed at 250°, 300°, 350°, 400°, and 500°C at constant speed (approximately 1 mm per sec) and constant die reduction. The extrusion product was a wire 1 mm in diam and approximately 20 cm long. In order to remove the surface layer with the "conical" texture and to reduce the absorption by the X-ray examination of the samples, the extruded wire was etched to 0.22 mm in diam. Experiments were performed in the middle sections of the 20-cm-long wires. In addition to the die of l-mm hole diam, dies with a 1.5-, 0.7-, 0.6-, 0.5-, and 0.4-mm hole diam and 63-deg die angle were constructed. In our experiments we did not find in these ranges any important difference concerning the texture of the extruded wires and we continued our work solely on the 1.0-mm die. The diffracted X-rays (Cu K radiation) were recorded photographically. Diffracted intensities were measured on the (111) reflection with a microphotometer. The relative amounts of texture components were determined from the areas under the diffracted maxima. We found the texture of extruded aluminum wires to be strongly influenced not only by the temperature of extrusion and the purity of the sample but also by the form of the die. It is generally admitted that cold-drawn aluminum wires have mainly a (111) texture with a small amount of (001) component, Table I of Ref. 1. In our experiments with wires extruded in conditions represented by Fig. 1, in some cases a single (001) texture was obtained. If these wires were drawn repeatedly at room temperature, X-ray measurements revealed a duplex (001)-(111) fiber texture. Further drawings increased the (111) and decreased the (001) texture component. In Fig. 1 the percentage of material oriented with (001) parallel to the extrusion direction is represented as a function of the temperature and the die angle (a), for commercial and refined aluminum samples, respectively. From these diagrams we may draw the following conclusions. The slope of the die (a) influenced more strongly the texture at the lower rather than the higher temperatures. Again, a stronger influence was found in the case of the commercial in comparison with refined aluminum samples. In the case of the commercial aluminum samples the amount of material with (001) texture increases with increasing wire temperature in an approximately linear manner. This effect is less pronounced in the pure aluminum samples, with the exception of the die with a = 45 deg. In this case the (001) texture decreases with increasing temperature, as shown in Fig. 1. Component (001) is more pronounced in higher-purity aluminum samples. Our experiments led to the conclusion that both (001) and (111) components are essentially stable in extruded aluminum wires. As we obtained a single (001) texture starting with a sample of drawn wire in which the (001) component was very weak, our experiments revealed that the (001) component is not a remnant of the initial texture; this is in disagreement with the findings of Vandermeer and McHargue.1 We gratefully acknowledge discussions with Professor M. Paic. 1 R. A. Vandermeer and C. J. McHargue: Trans. 7MS-AME, 1964, vol. 230, p. 667.

Jan 1, 1969