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By L. T. Leyson, U. C. Tainton

Some time ago, at ameeting of the Institute Prof. J. W. Richards1 said, "I take exception to the statement that all the factors in the production of electrolytic zinc were known long ago.... There is possible in my opinion an improvement of perhaps 50 per cent. in the new electrolytic processes." An examination of the literature of the subject will show the justness of Professor Richards' contention. The work of the earlier investigators was carried on in the shadow of difficulties that, today, are hardly more than memories. We seldom hear now of zinc sponge, that bête noir of the electrolytic-zinc pioneers. Zinc sponge was the name given to a peculiar, soft, black, non-adherent form of zinc deposit that was utterly useless for melting into ingot form. At the big plant at Cockle Creek, New South Wales, in 1897, Edgar Ashcroft2 said that the solution in the plant would suddenly, and without ascertainable cause, go' "bad" and begin to deposit spongy zinc. The most delicate, even spectroscopic, methods of analysis were unable to detect any difference between "good" solution and "bad" solution; either form might change to the other on being kept for a while. When it is added that an outbreak of this insidious disease (which appeared to be infectious, or at least contagious) could be dealt with only by discarding the solution and washing out all tanks and pipe lines, some idea may be gathered of the troubles of the zinc electrometallurgist in what may be spoken of as the "sponge age" of electrolytic zinc. Thanks to the efforts of a number of investigators, we are today able to diagnose with considerable certitude the nature of the malady that puzzled Ashcroft and his co-workers. The researches of Mylius and

Jan 1, 1924

By E. A. Gulbransen, J. W. Hickman

ONE of the important factors that determine the resistance of a metal or alloy to further chemical reaction is the structure of the superficial oxide film A thorough understanding of the physical and chemical structure as well as the stability of the oxide film formed on the surface as a function of time and temperature of the chemical reaction might furnish clues as to the nature of the reaction process and the protective nature of the film A comprehensive program has been undertaken to study these phenomena This paper summarizes the structure of the oxide films formed on the metals iron, cobalt, nickel, chromium and copper at temperatures up to 700°C Before the introduction of the electron diffraction technique, it «as necessary to use either direct chemical analyses or X-ray diffraction analyses to determine the nature of the oxide film formed on the metal or alloy Chemical analyses yields information on the percentages of the several atomic species present in the film while X-ray diffraction analyses yield information on the atomic geometry In special cases the information obtained may be identical, but in general both view-points are necessary Much of, the early work was carried out on the oxidation of bulk samples where thick films were obtained The products were identified after cooling to room temperature by X-ray diffraction and chemical analyses Although much useful information has been obtained in this manner, little could be learned about the character of the protective oxides during the period when the films were actually protective Evidence concerning the chemical structure of thin oxide films has been made possible by the development of the electron diffraction reflection technique In this method the most fruitful investigations have been made by carrying out the reaction in situ at the temperature at which the film is actually protective LITERATURE The oxidation of iron has been extensively investigated by X-ray and electron diffraction Jackson and Quarrell1 found that oxide films formed and examined at the same temperature differed considerably from those allowed to cool to room temperature The results showed that below 400°C the oxide that was stable in intimate contact with iron was Fe304, between 515° and 900°C the stable film was FeO Above the upper change point of iron the oxide was found to be Fe304 prom 400° to 515°C , FeO, Fe304 or a mixture of the two oxides was found Recrystallization of the air-formed film below 400° and above 900°C led to the formation of Fe304 In the range where thicker films consisted of FeO, the air-formed film was converted to a new hexagonal oxide not previously described

Jan 1, 1946

THE Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties situated at 29 West 39th Street in New York City.

Jan 1, 1946

By B. W. Gandrud

WET-PROCESS coal-washing tables as we know them today have been in use in this country for approximately 25 years. The literature records only a few table installations worthy of note prior to adoption of the present-day differential-motion table. According to Phillips,' six Campbell bumping tables were being operated by the St. Bernard Coal Co., Earlington, Ky., in 1893. As late as 1923, according to Richardson, 72 such tables were in operation in the Rosedale washery of the Cambria Steel Co., at Johnstown, Pa. Bumping tables probably were not used to any considerable extent except in the plant at Earlington, and at two or three plants in Pennsylvania, but they may be considered as forerunners of the present-day coal-washing table. The transition from bumping tables to the type of tables now in use signalized a revolutionary change iii table design. The advantages of the new design over the old were so outstanding as to make its adoption inevitable. BUMPING TABLES Bumping tables, as the name implies, utilized a bumping action for conveying the refuse and discharging it over the refuse end. The tables were hung from rods attached to overhead supporting beams. A shaft and cam arrangement at one end of the table served as ,the actuating mechanism and imparted to the table an endwise, back-and-forth, swinging motion. A bumping block was fixed in the proper position at the shaft end, so that the table would strike against it at the end of each backward swing. The hanger rods or stirrups were so adjusted as to give the table a slight uphill slope toward the refuse end; that is, the end next to the driving mechanism. The feed box was near the upper end of the table and designed to spread the mixture of coal and water over the width of the table. Wash water was added a short distance below the feed box. With the table in motion and coal mixed with water being fed to it through the feed box, a certain amount of stratification took place, depositing heavy refuse at the bottom of the bed in contact with the surface of the table. Constant bumping and a certain amount of

Jan 1, 1943

By R. G. Aspden

The cold rolling and annealing textures were studied for 3 pct Si-Fe grains initially (001) [hkl]. A concentration of (001) [loo] primaries were observed only in the annealing textures of crystals initially having [loo] within 8 deg of the rolling direction. Eke annealing textures of the (001) [I101 cold rolling textures were sensitive to the initial orientation of the grains. Single crystal data were used to explain the formation of (001) [loo] in poly-crystalline malerial. CUBE texture formation in 3 pet Si-Fe sheet occurs during the final high temperature anneal. Its formation is dependent on the proper distribution of (001) plane primaries with reference to the rolling direction&apos; and on the growth of these primaries by secondary recrystallization. The selective driving force for these primaries with (001) within 7 deg of rolling plane is derived from the difference in surface energy between the annealing atmosphere and the crystallographic planes exposed at the surface of the sheet.&apos;-= The alignment of [loo] directions of (001) secondaries with the rolling direction is required for optimum magnetic characteristics7 and is dependent on processing.&apos; A high degree of alignment has been observed when the final cold rolled texture has a strong (111) [ll2] type component3 and the normal grain growth texture prior to secondary recrystallization has components with a [loo] parallel to the rolling direction and planes from (001) to (110) parallel to the rolling plane.1,3,8,9 Generally, this (001) component is much weaker than the (110) component. The growth rate of (001) plane primaries to secondaries has been found to be independent of the orientation of the primaries with reference to the rolling direction, i.e., the secondaries have the same degree of alignment of [loo] directions with the rolling direction as the (001) primaries.&apos; Hence, the rolling and annealing textures of individual grains or single crystals are of interest in understanding the development of the (001) [loo] secondary recrystallization texture. (001) components have been observed in the annealing textures of cold rolled grains initially having a [loo] parallel to the rolling direction and an (001) rotated up to 30 deg from the rolling plane. Crystals initially near the (001) [loo] orientation when rolled under the influence of constraints imposed by neighboring grains form deformation bands and ro- tate in both directions toward (001) <110>.10,11 Deformation bands have been reported also for crystals initially with an (001) within 1 deg of the rolling plane and a [loo] within 1 deg of the rolling direction when rolled as a free single crystal.12 These crystals have weak recrystallization textures and contain near an (001) [loo] component.10-12 When near (001) [loo] crystals are rolled as free single crystals no deformation bands form and the crystals rotate by a single rotation toward (001) [110]. Recrystallization after a 70 pct cold reduction yielded near an (001) [loo] component13 and after a 90 pct cold reduction an (001) [I201 component." Crystals initially near (210) [001] had a texture after a reduction of 70 and 84 pct which was similar to the (111) [li2] but rotated 10 to 15 deg in the transverse direction. These crystals recrystallize to (210) [OOl] or (410) [001] and contain an (001) [loo] component.10,13 An (001) component has not been detected in the normal grain growth textures of other single crystals. Crystals initially having orientations between (110) [001] and (111) [ll2] have a cold rolled texture of principally (111) [ll2] .10>16 Other crystals with a [I101 parallel to the cross direction rotate to (111) [112] and/or (001) [110] stable end orientations. Crystals initially having from (001) [110] to (111) [lie] retain this orientation after cold rolling.15 The cold rolled textures having [I101 directions parallel to the rolling direction had components in the annealing textures related to the deformation textures by 25 to 30 deg rotations about common (1 10) poles. Cold rolled textures of the (111) (112) type recrys-tallized to (120) [001] or (110) [00l]. The purpose of the present work was to further the understanding of the alignment of [loo] directions of (001) secondaries with the rolling direction. The cold rolling and annealing textures of grains initially (001) [hkl] were studied. These data were applied to the formation of (001) [loo] by secondary recrystallization. PROCEDURES AND EXPERIMENTAL TECHNIQUES The (001) poles near the sheet normal and rolling direction are given in Fig. 1 for the 10 grains studied. Each of these grains was located in the center of a polycrystalline specimen approximately 25 mm wide and 50 mm long. The lower case lettered grains, a through dl were about 1.2 mm in diam and near the (001) [loo] orientation. Specimens containing these grains were from a commercial 3 pct Si-Fe alloy with the principle orientation of (110) [001] as obtained by impurity inhibition of growth with manganese sulfide inclusions.17,18 Upper case lettered grains, A through F, were about 6 mm in diam and had (001) planes near the rolling plane and [hkl] di-

Jan 1, 1963

By Chas. Y. Clayton, Francis B. Foley, W. E. Remmers

DuRing the summer of 1919, the late Dr. Henry M. Howe, then Chairman of the Division of Engineering of the National Research Council, organized a committee to obtain a better insight into the behavior of carbon steels under the influence of various treatments by a proper control of the time and temperature factors. During part of 1919 and 1920, work in connection with this investigation was carried on at Dr. Howe&apos;s laboratory at Bedford Hills, N. Y. During 1921 there was an enforced hiatus in the work, occasioned by the illness which resulted in Dr. Howe&apos;s death in 1922. At that time one of the present authors compiled the results of the work which had been done and this was published in 1923.&apos; Following the publication of this work, it seemed desirable to carry on in the same manner an investigation of steel of C 0.75 per cent., which steel had not been as fully treated as had the other steels of C 0.34 and 0.52 per cent., used in the published work. Furthermore, certain unusual results have been obtained in the treatment of C 0.52 per cent. steel by quenching and drawing, and repetition of this part of the work seemed advisable. This has been done during the past year at the School of Mines and Metallurgy of the University of Missouri at Rolla, Mo., by a cooperative undertaking of the School and the Bureau of Mines, working in conjunction with the Committee on Heat Treatment of Carbon Steels of the National Research Council. The present paper is a report of the results obtained in this work.

Jan 1, 1926

By J. T. McGrath, G. B. Craig

Tensile tests on aluminum single crystals, grown from the melt, revealed that the yield stress of these crystals was raised as the amount of striation substructure was increased. The number of striation-type boundaries was varied by changing the rate of growth of the crystals. The results are interpreted in terns of a blockage of dislocation movement by striation boundaries. IMPERFECTIONS are known to have a large effect on the mechanical properties of metals. Teghtsoonian and Chalmers 1 studied a block or striation-type substructure in tin and found that the formation of the striations depended upon rate of crystal growth and orientation. They found that the angular misorienta-tion between neighboring striations varied between 15 min and 5 deg. Atwater and chalmers2 investigated striations in tin and lead, and found that purity was another factor which influenced their formation. There was a limiting purity above which the striations were straight and regular. There is little information in the literature concerning how substructures in melt-grown crystals affect strength. washburn3 introduced small-angle boundaries into zinc by a shear process and found a subsequent increase in yield stress which he attributed to the presence of these boundaries. Lauriente and pond4 found the critical resolved shear stress in aluminium crystals grown from the melt, to increase with etch pit density. The etch pits were used as an indication of growth imperfections. In Hibbard&apos;s5 work on lineage structure in copper crystals grown from the melt, he tested one crystal containing interlineage boundaries, and found a 50 pct increase in the critical resolved shear stress. Fleischer and Chalmers6, in a recent paper, mention briefly that, in the production of aluminium crystals from the melt when the growth rate was raised from 1.2 to 18 cm per hr, the yield stress increased 50 pct. They felt that the increase in yield stress with rate of growth might be attributed to a higher concentration of impurities in the gage length and also might be affected by the increased number of small-angle boundaries (striations). The present investigation was undertaken to determine the effect of the striation substructure on the strength of aluminum single crystals. EXPERIMENTAL PROCEDURE Aluminum single crystals of 99.9992 purity were grown from the melt using a technique described by Chalmers.7 The growth rate was varied from 0.6 to 20 mm per min, thus producing crystals with varying numbers of striation boundaries. To avoid prior deformation, the crystals were chemically cut to the desired length with a saturated solution of cupric chloride. They were then annealed at 580°C for 24 hr and allowed to cool slowly in the furnace. Finally, the specimens were electropolished using an electrolyte of 5 parts ethyl alcohol and 1 part perchloric acid. Each specimen was approximately 5 in. in length and 0.125 sq in. in cross section. The average orientations of the 5 series of crystals studied are shown on the stereographic projection of Fig. 1. The crystals were strained approximately 2 pct in a soft tensile machine. The strain sensitivity was 3.6 x 10-4 cm over a 5-cm gage length.

Jan 1, 1960

By Walter B. Devereux

Metallic copper is a product of native metallurgy in various parts of Mexico, and by somewhat varied processes. While recently examining copper mines in the State of Jalisko, I had an opportunity of witnessing Mexican copper smelting by a process which I have not seen described, and which is interesting from the fact, that a fine quality of copper is produced from sulphurous ores in three metallurgical operations, and apparently without excessive loss. The process was carried on in buildings which were part of a plant erected by an American more than twenty-five years ago for the purpose of smelting and working copper. After a few years this man met with accidental death, and the works have been but little used since. Located in the centre of a high range of mountains, far from any town or seaport, and inaccessible except over difficult mule trails, these substantial buildings, filled with furnaces and heavy machinery,

Jan 1, 1883

INCREASING realization that pouring and ingot-mold practices involve many factors of fundamental importance to ingot quality and general steel-mill operations has caused these phases of steelmaking to become major concerns of operators and metallurgists engaged in control of quality and costs. Methods of pouring steel from the ladle into the ingot molds have some direct effects on ingot quality. The mold itself governs solidification and dimensions of the ingot and in so doing exerts some very tangible influences not only on ingot quality but also on product yields and general steel-mill processing. In addition, practices are employed in the handling of molds during daily open-hearth operations that are important to quality and production costs. Therefore, pouring and mold practices must be considered highly specialized and important steps in steel-mill operations. MOLD DESIGN Mold design is difficult to discuss in a precise manner because it varies greatly throughout the industry, both in theoretical concepts and practical application, and few well developed data are available. Most ingot molds are designed to meet conditions peculiar to a given plant wherein quality standards are dictated by end-use requirements, which may differ considerably even for the same grade of steel. The mold designer must also consider the equipment available to process ingots and the product obtained from them. Such equipment, used for stripping, heating, blooming and finishing operations, is seldom, if ever, exactly the same in any two steel plants. Thus, pronounced contrasts in mold designs can be expected to continue, even among plants making strictly comparable types of product, particularly because some producers are just beginning to realize the benefits possible from specialized designs. Certain fundamentals are used in mold design but even these

Jan 1, 1964

By R. E. Zimmerman, Michael Sokaski, E. R. Palowitch, M. R. Geer, H. F. Yancey, W. Deurbrouck, S. C. Sun

PART 1: DENSE MEDIUM SEPARATION by M. SOKASKI, M. R. GEER and H. F. YANCEY INTRODUCTION In the early days of coarse-coal treatment by the dense-medium process in Europe, loess was one of the materials used for medium solids. Newly developed cyclones were used to reclaim and thicken :he loess suspension. On occasion, when the cyclone thickener at the Maurits mine in the Netherlands plugged, the overflow was found to be filled with clean coal free of impurity. From this observation stemmed the concept of the cyclone as a cleaning device. Development took place during World War 11 in the laboratory of the Dutch State Mines under the direction of M. G. Driessen. A 15-ton-per-hour pilot plant was in operation in the laboratory by 1945, when, in September, Driessen made the first public disclosure of the process in a paper presented to the Institute of Fuel in London. In April 1945,2 operation of this pilot plant was observed by one of the authors, who was so impressed with the potential of the cyclone process that, on his return to the United States, a research program on the cyclone was started by the Bureau of Mines immediately. This work led to an AIME paper in 1946 in which the first details of cyclone operation on American coals was made available. Commercial adoption of the cyclone proceeded in Europe, initially in the Netherlands, Germany, and France. In the United States, where coal is less costly and most of the coals are so easy to clean they respond well to simpler cleaning systems, the first cyclone plant was not built until 1961.3 As of the spring of 1967, a total of 31 commercial cy- clone plants had been installed or were under construction in the United States; this does not include eight Dynawhirlpool plants. The capacity of the cyclone plants ranges from 50 to 1300 tons per hour and totals 6600. THEORY Before discussing the theory of a dense medium cyclone, a brief description may be helpful to some readers who are not familiar with its basic operation. In a typical dense-medium cyclone, illustrated in figure 10-1, the mixture of medium and raw coal enters tangentially near the top of the cylindrical section, thus forming a strong vertical flow. The refuse moves along the wall of the cyclone and is discharged through the under- flow orifice. The washed coal moves toward the longitudinal axis of the cyclone and passes through the vortex finder to the overflow chamber.

Jan 1, 1968

By D. L. King, B. A. Schepman

A number of unique thickener mechanism designs with the operating results achieved in various installations are discussed. These unusual designs include new types of raking arms, lifting devices, and feed-wells employed to obtain higher underflow densities and minimum operator control or improved overflow clarity. Several installations of large thickeners in which the underflow lines pass upward through the center to eliminate tunnels are reviewed. The location of the lines and pumps with the maintenance and operating records are included. Several types of automatic lifting device controls are used to provide storage in the thickener. Some of the installations employing underflow density controls are achieving excellent operating results. Thickeners or sedimentation basins are used in minerals beneficiation plants for three basic purposes. These are 1) Concentration, or to raise the density of a liquid-solids slurry. 2) Clarification, or removal of finely divided solids from a slurry. 3) Hydroseparation, or removal of a specific fraction of solids from a slurry. The concepts that control the size and configuration of basins used for these purposes are different. Likewise, different equipment is properly employed to accomplish these various objectives. The pattern of liquid and solids flow in the clarification zone of a sedimentation basin used for thickening or raising the density of a pulp normally is not critical. That is, the solids normally will drop or plunge to the bottom quite readily, and the liquid separates itself from these solids so as to overflow the basin in a relatively clear condition. When clarification or removal of finely divided particles is to be accomplished, the flow patterns in the basin are extremely important. The velocity of the incoming stream must be dissipated and the liquid flow distributed ]In the tank so that the feed is not divided into streams that flow directly to the overflow carrying the fine:ly divided solids that are to be removed. Similarly, the configuration of the arms that provide the raking and thickening of the pulp is not as important in basins primarily devoted to clarification. In thickening, the design of the arms and the manner in which the pulp is moved or worked, can contribute appreciably to the thickening process and achievement of a higher density underflow. THICKENING As the grade oi ore bodies throughout the world generally decreases, and chemical processes, hydro-metallurgy, and other more refined methods of minerals beneficiation are required, problems in thickening become more acute. Difficult operating conditions, previously encountered only occasionally in thickening metallurgical slurries, or clarifying process streams in the mill, are now the rule rather than the exception. Fig. 1 illustrates some of the different types of raking arms that are successfully achieving the desired goals in pulp thickening. The conventional raking arms consist of a relatively simple truss with the blades attached to the bottom chords. This design provides proper Concentration of many &apos;normal&apos; slurries. A modificaiion of this design as shown in the center is being used with excellent results on large thickener basins where it is desirable to have a

Jan 1, 1962

INTRODUCTION IT is 10. years this summer since the first of the contributions which it has been my privilege to make to the working tools of the hydrometallurgist was set at work, but a full description of what has come to be known as "Dorr Machinery" has never been published in the Transactions of the Institute, and it has been suggested to me that an account of the same would prove of interest to members, although most of those engaged in cyaniding and concentration are probably familiar with it. The account which I shall give of the development of the machines must be recognized as being written from the viewpoint mainly of my own local experience and not from that of one who was familiar with the general metallurgical practice throughout the world. Most advances in any art are conceived before the time is ripe for their development and any .invention which comes into general use will usually be found to have been tried out in a crude way and abandoned more than once. If the early experimenter went as far as the Patent Office, his work may serve no other purpose than to prevent the issuance of the broadest patent to those who later may develop a commercial process. The cyanide process in the United States early in 1904 was mainly confined to the leaching of dry crushed ores, both coarse and fine, and sand treatment of tailings from concentration and amalgamation. In the Black&apos; hills some plants were crushing in cyanide solution, leaching sands and handling the slime by the well-known decantation process. Filter pressing, in use for some years in Australia,had been tried in several places in this country and the Moors process had been abandoned at Mercur after&apos; a short run, but was doing good work at the mill of Lindbergh, Dorr & Wilson, at Terry, and being installed at Bodie and the Liberty Bell. A general feeling, however, still existed that, slimes were to be avoided when possible, on account of the losses in treatment and the difficulty of making a good leaching product when they were present in large amounts, especially when the crushing was done in cyanide solution.

Jan 8, 1914

By F. Weinberg

It has been suggested, for some time, that the behavior of metals under high-temperature creep conditions is strongly influenced by the behavior of the grain boundaries present in the material. This has led to a number of investigations1-6 in which attempts were made to measure the properties of the grain boundaries themselves, both to determine their contribution to the creep process and to obtain further knowledge of their intrinsic structure and properties. The present investigation was undertaken to extend the observed data under more closely controlled experimental conditions and to attempt to clarify sonie of the discrepancies in the literature. A brief report of the preliminary results has been published.7 EXPERIMENTAL PROCEDURE For the present investigation, controlled orientation specimens were used having plane boundaries which terminated at the specimen surface. Trierys-tal specimens were used instead of the bicrystal type of Puttick and King,&apos; in order to simplify the gripping technique required to apply a shear stress along the boundary. The aluminum used was obtained from the Aluminum Francaise and was of 99.994 pct purity, containing 0.002 pct each of Cu, Fe, and Si. The aluminum tricrystals were grown horizontally from the melt, in graphite boats, and in an argon atmosphere, following the technique developed by Chalmers.&apos; The orientation of the tricrystals was controlled by using seed crystals separated by mica inserts. Thermal conditions were adjusted to produce tricrystals having boundaries which were macroscopically straight, parallel to the growth direction, and perpendicular to the top surface. Following growth, the tricrystals were carefully cut with a jeweller&apos;s saw to the test specimen shapes shown in Fig. l(a) and l(b). In Fig. 1(a), the boundaries subjected to shear stresses are indicated AB and CD: Points A and C are the ends of the mica inserts separating the seed crystals; points B and D are at lateral cuts made in the specimen. It was found that the slots left by the mica inserts at A and C had to be enlarged slightly, by cutting, to ensure that the boundary terminated freely at these points. A shear stress was applied to the boundarks by gripping the upper two legs in file-faced Inconel grips and suspending a weight from the lower part of the specimen held in similar grips, as shown schematically in the diagram. The test specimens shown in Fig. 1(b) were cut from long

Jan 1, 1959

By N. A. Gokcen, John Chipman

D. C. Hilty (Union Carbide and Carbon Research Laboratories, Niagara Falls, N. Y.)—This paper is a very nicely detailed analysis of a difficult problem. I would like to point out that the results that Mr. Crafts and I published a few years ago had no reference to activity, or anything else of a similar nature; our results were strictly empirical. It is quite gratifying that we now have a case where results involving activity coefficients and results derived from direct observations on actual steel melts are practically identical. When two different laboratories, working from two entirely different approaches, come out with results in such good agreement in their major significance, that is an achievement. It is something that was not possible 15 or 20 years ago. There is one question I would like to ask Dr. Chip-man. It has to do with a very minor point of disagreement in these results. When we reported the kink in the Si-O solubility curve I think you may recall that it came at the different temperature levels at about the order of 0.015 to 0.03 pct 0 and 0.03 to 0.07 pct Si—we also pointed out that we had difficulty in obtaining data at that level, although we finally did get some. I note in going through the data for the present paper, that there are no samples in those particular silicon and oxygen ranges. I wonder if that was purely accidental or was there a reason for it. D. E. Babcock (Republic Steel Corp., Youngstown, Ohio)—Mr. Hilty, do you have any explanation for that discrepancy between Dr. Chipman&apos;s curve and your own Mr. Hilty—Our explanation for it at that time was that for some reason our system probably was not in true equilibrium with SiO, that is, in equilibrium with the silica crucible at that level. We did observe, however, that that was the level at which both the metal and the slag became saturated with SiO,. On the average, in studying inclusion formation in small ingots permitted to solidify normally from the molten state, we observed pure silica inclusions at silicon contents over about 0.05 pct and FeO type inclusions at silicon

Jan 1, 1953

By A. H. Daane, R. L. Myklebust

The yttrium-manganese system has been investigated by thermal, metallographic, and X-ray diffraction methods. There are three intermetallic compounds present: YMn2 which melts congruently, YMn4, which undergoes syntectic decomposition, and YMn,, which undergoes peritectic decomposition. The compound YMn4 is ferromagnetic at room temperature with a Curie temperature of 214°C. There are eutectics at 25.2, 60.9, and 82.0 wt pct Mn which melt at 878°, 1100°, and 1075°C, respectively. Crys-tallographic data are given for YMn4, and YMn12 . The terminal solid solubilities are low. In a general program of study of yttrium metal in this laboratory some alloy systems of this metal with elements of the first transition period have been examined. This work was originally instigated by experiences in cladding yttrium with jackets of some protective metals such as Inconel for high-temperature service in air.&apos; In some cases a low-melting phase was observed to form between the Inconel and the yttrium resulting in failure of the samples. In characterizing this reaction, a survey was made of the systems of yttrium with chromium, manganese, iron and nickel,, and it was found that a eutectic was formed between these metals and yttrium on the yttrium-rich side of the system. This present study of the Y-Mn system was carried out to examine in more detail the alloying nature of yttrium, and to correlate trends that have been observed in previous related studies. It was observed by Voge13 that in the systems of lanthanum, cerium, and praseodymium with each of the metals in the first transition series, the tendency to form compounds diminished in the order nickel, cobalt, and iron while no compounds were formed with manganese, chromium, or titanium. Beaudry and Daane4 observed a similar behavior in the systems of yttrium with some members of the first transition series except that the tendency for compound formation was greater. Both the Y-Ti5 and Y-Cra systems consist of simple eutectics, while in the Y-Fe,7 Y-CO, and Y-Ni4 systems, there are four, eight, and nine compounds, respectively. In addition to the above trends, the similar atomic radii and electronegativities of yttrium and thorium invite a comparison between their alloying behaviors with a common element such as manganese. In crys- tallographic studies, Florio et al.&apos; have identified three intermediate phases in this system which are ThMn2, Th6Mn23, and ThMn,,. Gschneidner and Waber10 have examined published information on alloy systems of the rare-earth metals and have correlated this information with current alloying theory. From their study, they predicted that the Y-Mn system would contain one intermetallic compound. On the basis of this prediction, the trend in the alloying behavior of yttrium with the elements of the first transition series and the alloying behavior of thorium with manganese, one might expect from one to three intermetallic compounds to form in the Y-Mn system. A consideration of Hume-Rothery&apos;s rules of alloying based on size-factor, electronegativity, and valency suggested a small terminal solubility and possible compound formation. The present study was undertaken to confirm these predictions of low terminal solid solubility and compound formation and to establish the general alloying behavior of yttrium with manganese. EXPERIMENTAL Materials. The manganese used in this investigation was obtained from the Foote Mineral Co. as electrolytic plates of 99.9 pct stated purity; the yttrium metal was prepared in this laboratory. Table I gives the analyses of these materials. For the solubility studies at the yttrium-rich end of the alloy system, distilled yttrium, whose major impurity was 200 ppm Ti, was used. Preparation of Alloys. The alloys were formed by comelting the two metals in an are-melting furnace under an atmosphere of argon. The buttons thus formed were inverted and remelted three to five times to promote homogeneity. Due to the high vapor pressure of manganese, it was assumed that the weight lost during are-melting was all manganese. This assumption was based on the very good agreement observed between calculated compositions and chemical analyses of several alloys. The compositions of the dilute alloys used for solid solu-

Jan 1, 1962

By W. M. Rust, W. D. Mounce

THE almost universal acceptance of electrical logging by the petroleum industry calls for a critical examination of the physical bases of the common methods. This is particularly needed for the natural potential log. The conventional explanations are based on the phenomena of electrofiltration and electro-osmosis. However, experimental data show that they fail to give a basis that is quantitatively sound. Moreover, they lead to interpretations of details of electrical logs that are erroneous. It was found experimentally that when a plug of shale is placed in a chain of dissimilar electrolytes, a current flow results. Experiments on oil-well cores and fluids similar to those existing in wells show that potentials are set up which are in reasonable agreement with those encountered in electrical logging. Doubt- less other sources of potential are important but this explanation not only accounts for much of the potential but also clarifies some fairly familiar examples of misinterpretations.

Jan 1, 1944

By J. W. Hickman, E. A. Gulbransen

In a previous paper&apos; the authors have investigated the structure of the oxide films formed on most of the metals that make up the alloys of this study. The metals were studied in order to provide basic information on the structures, both physical and chemical, of the oxide films and to determine how these structures are effected by the temperature, time of oxidation, and surface preparation. It was felt that an understanding of the physical and chemical structure as well as the stability of the oxide film might furnish clues as to the nature of the reaction process and the protective quality of the film. The oxidation of the metals was studied over the temperature range 300&apos; to 7o0°C. except for copper, wherc the range selected was 100&apos; to 500°C. The results of these studies were presented in graphical form as existence diagrams of the oxides on a time-temperature scale. For some of the metals the existence diagrams were simple and showed few chemical transitions, but there were numerous cases where the physical state of the oxide surface was a function of time and temperature. In general the physical state of the oxide surface changed with increasing temperature so as to increase the sharpness of the diffraction patterns and to cause orientation effects to be more pronounced. Deviatiois in lattice Darameters from X-ray values were noted. In general these deviations were of positive nature and may be due to solid solution of the metal in the oxide lattice. This effect might be expected in thin oxide films. In a study of the oxidation of alloys containing two or more metals, there may arise the complicating factor of identification of the oxides formed. A thorough understanding of the oxides formed on the pure metals, therefore, was, essential before investigation of the oxidation of alloys. In this paper it is our purpose to present a study of the following problems: 1. The existence diagrams of various alloys. 2. The effect of the structure of the alloying metal on the existence diagram of iron. 3. The effect of the percentage of chromium on the oxides formed on Fe-Cr alloys. 4. The relationships, if any, between the oxides formed and the protective quality of the oxides. The following alloys are included in this study: alloys of iron with body-centered cubic, face-centered cubic and other metals, 13 Cr-Fe, 18-8 stainless steel, K4²B, Nichrome V, Hipernik, Inconel, Stellite "²I," Refractaloy, Kovar, mild steel, a series of Cr-Fe alloys and a series of Co-Fe alloys. Since many of the commercial alloys in this list contain more than two metals, various complicating factors in the identification of the oxides formed may arise.

Jan 1, 1947

By E. A. Gulbransen, J. W. Hickman

In a previous paper&apos; the authors have investigated the structure of the oxide films formed on most of the metals that make up the alloys of this study. The metals were studied in order to provide basic information on the structures, both physical and chemical, of the oxide films and to determine how these structures are effected by the temperature, time of oxidation, and surface preparation. It was felt that an understanding of the physical and chemical structure as well as the stability of the oxide film might furnish clues as to the nature of the reaction process and the protective quality of the film. The oxidation of the metals was studied over the temperature range 300&apos; to 7o0°C. except for copper, wherc the range selected was 100&apos; to 500°C. The results of these studies were presented in graphical form as existence diagrams of the oxides on a time-temperature scale. For some of the metals the existence diagrams were simple and showed few chemical transitions, but there were numerous cases where the physical state of the oxide surface was a function of time and temperature. In general the physical state of the oxide surface changed with increasing temperature so as to increase the sharpness of the diffraction patterns and to cause orientation effects to be more pronounced. Deviatiois in lattice Darameters from X-ray values were noted. In general these deviations were of positive nature and may be due to solid solution of the metal in the oxide lattice. This effect might be expected in thin oxide films. In a study of the oxidation of alloys containing two or more metals, there may arise the complicating factor of identification of the oxides formed. A thorough understanding of the oxides formed on the pure metals, therefore, was, essential before investigation of the oxidation of alloys. In this paper it is our purpose to present a study of the following problems: 1. The existence diagrams of various alloys. 2. The effect of the structure of the alloying metal on the existence diagram of iron. 3. The effect of the percentage of chromium on the oxides formed on Fe-Cr alloys. 4. The relationships, if any, between the oxides formed and the protective quality of the oxides. The following alloys are included in this study: alloys of iron with body-centered cubic, face-centered cubic and other metals, 13 Cr-Fe, 18-8 stainless steel, K4²B, Nichrome V, Hipernik, Inconel, Stellite "²I," Refractaloy, Kovar, mild steel, a series of Cr-Fe alloys and a series of Co-Fe alloys. Since many of the commercial alloys in this list contain more than two metals, various complicating factors in the identification of the oxides formed may arise.

Jan 1, 1947

THE preceding chapter has recorded the initiation of mineral industry education during the period 1890-1910 in numerous institutions that had not previously offered it. It should also be emphasized that in many institutions where instruction had begun before 1890, as recorded in earlier chapters, but had not yet become firmly established, this period was one of marked growth and development. This was not universally true, however, for at the Universities of Pennsylvania, Michigan, Illinois, Wisconsin, Washington (St. Louis), Iowa, Vanderbilt and Tennessee, and at the Polytechnic College of Pennsylvania, mineral industry instruction was being dropped during this period, instead of gaining in strength. It is necessary to emphasize this, because writers on the subject have not infrequently attempted to make a much too simple correlation between mineral discovery or production and the intensity of student interest in mineral industry curricula. It would naturally be true that periods of large mineral production would, in general, coincide with cycles of business prosperity, and the latter are conducive to starting new ventures, educational as well as business. It should be equally evident that opportunities for business and professional success might, in such periods, appear to increase at a more rapid rate in industries other than mineral, or in the utilization of minerals rather than in their production. The author has not been able to perceive any simple and clear relation between interest in mineral industry education and mineral discovery, production, and utilization, or general business prosperity. On the contrary, the more the problem is studied the more complex the factors involved in it appear to be. In a later chapter an attempt will be made to analyze them in more detail

Jan 1, 1941

By George K. Burgess, Robert A. Hadfield

1. Introduction.—The methods of production of sound steel ingots have been described in several papers read recently before this Institute. It was thought by Director Stratton, of the U. S. Bureau of Standards, and ourselves to be of sufficient interest and importance, as a further contribution to this subject, to compare the properties of rails rolled in one mill according to American practice, from several types of ingot of substantially the same chemical composition but cast by several processes; and to compare in considerable detail the properties of an ingot manufactured by the Hadfield special-feeding process and one of the usual type for rolling into rails. We are greatly indebted to F. W. Wood, President of the Maryland Steel CO., who made this investigation possible by kindly placing his rail mill at our disposal; and he and his associates at Sparrows Point did everything possible to make the experiment a success, including the execution of several of the tests and analyses. 2. Classification and Manufacture of Ingots.—Of the ingots used in this investigation, eight were made in Sheffield and furnished by Sir Robert Hadfield, and one was made and furnished by an American steel company,l as a comparison ingot, and was supposed to represent the usual type of ingot from which rails are made. The characteristics of the ingots are given in Table I. Ingots 1, 2, 3, and 4 were cast large end up and fed by the Hadfield method in the usual manner with charcoal and blast continued until the molten steel has set on the top of the head, say varying from 20 to 40 min. To ingots 1, 2, and 4 was added 0.1 per cent. aluminum, and to the nickel-chrome ingot, No. 3, 0.125 per cent. For sake of comparison, there were also included two ingots, Nos. 8 and 9, cast with the small end up and fed by

Jan 1, 1915