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By Henry Fernald

THE accounting system or bookkeeping methods of any company are principally the concern of that company and of those who are in control of its affairs. Its published financial report is, however, primarily intended for those who are not already fully informed regarding its operations and finances. Whatever may be the advantages of standardization of accounting and bookkeeping methods, it must be admitted that a company has a certain right to handle its accounts and keep its books and records in whatever manner may seem to it best adapted to its affairs, even though such methods may differ materially from those generally adopted by others. In its financial reports it should not, however, either ask or expect that the statements it makes or the terms which it uses will be given in its case a meaning and interpretation different from that which they are ordinarily considered to have in similar reports and statements of other companies. The particular form and arrangement of such reports is a matter concerning which there may be much difference of opinion. It is of little importance whether current assets come first or last in the Balance Sheet, but it is important that there should not be included under this designation any items which are not properly current assets within the generally accepted meaning of that term. The extent to which stockholders or others interested are to be made acquainted with the full details of a company's business is a question which the proper authorities must in each case decide. It should, however, be recognized that there are certain facts regarding a mining com-pany which must be set forth in a financial statement if it is fully to cover the conditions and affairs of the company. For example, a financial, statement which does not include or is not accompanied by a statement, of the ore reserves of the company does not fully set forth its financial condition. This is true whether the absence of such a statement of ore reserves is because it is not desired to make public the figures or whether it is because the ore reserves themselves are not definitely known, or accurately measured.

Jan 1, 1928

Temperatures in the Open-hearth Furnace. By Robert B. Sosman. (Metals Tech. Aug. 1948, T.P. 2435) Steelmaking Direct Oxidation in the Basic Open Hearth Process. By E. R. Hughes and F. G. Norris. (Metals Tech., June 1948, T.P. 2380) With discussion Operation of Oxygen-enriched Open-hearth Furnaces. By J. S. Marsh. (Metals Tech., Aug. 1948, T. P. 2416) With discussion Role of Thermochemical Factors in Basic Open Hearth Production Rate. By T. E. Brower and B. M. Larsen. (Metals Tech., Oct. 1948, T.P. 2451) Structure, Segregation and Solidihcation of Semikilled Steel Ingots. By M. Tenenbaum. (Metals Tech., Sept. 1947, T.P. 2273) With discussion The Origin of Silicate Inclusions in Basic Electric-arc-furnace Steel of Higher Carbon Contents. By Axel Hultgren. (Metals Tech., Aug. 1948, T.P. 2418) A Method for Determining the Origin of Surface Defects in Rolled Steel Products. By C. L. Meyette and V. L. Elliott. (Metals Terh., June 1948, T.P. 2368) With discussion Gases in Steel The Sampling and Analysis of Steel for Hydrogen. By G. Derge, W. Peifer and J. H. Richards. (Metals Tech., June 1948, T.P. 2362) With discussion Apparatus for the Hot-extraction Analysis for Hydrogen in Steel. By C E. Sims and G. .I. Moore. (Metals Tech., June 1948, T.P. 2369) With discussion A Quantitative Experimental Investigation of the Hydrogen and Nitrogen Contents of Steel during Commercial Melting. By C. E. Sims, G. A. Moore and D. W. Williams. (Metals Tech., Feb. 1948, T.P. 2347) With discussion The Effect of Hydrogen on the Ductility of Cast Steels. By C. E. Sims, G. A. Moore and D. W. Williams. (Metals Tech., Sept. 1948, T.P. 2454) Sulphur in Ironmaking Kinetics of the Transfer of Sulphur across a Slag-metal Interface. By Lo-ching Chang and K. Goldman. (Metals Tech., June 1948, T.P. 2367) With discussion Some Correlations between Variables Affecting Sulphur in Blast Furnace Iron. By T. E. Brower and B. M. Larsen. (Metals Tech., Sept. 1948, T.P. 2465) Tracer Study of Sulphur in the Coke Oven. By S. E. Eaton, R. W. Hyde and 11. S. Old. (Metals Tech., Sept. 1948, T.P. 2453) Transformation of Austenite Anisothermal Formation of Bainite and Proeutectoid Constituents in Steels. By Leonard D. Jaffe. (Metals Tech., Dec. 1947, T.P. 2290) With discussion Austenite Transformation Above and Within the Martensite Range. By R. T. Howard, Jr. and M. Cohen. (Metals Tech., Oct. 1947, T.P. 2283) With discussion

Jan 1, 1949

Report of Secretary TO THE BOARD OF DIRECTORS OF AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS Gentlemen -I have the honor to present the following report for the calendar year 1920 The activities which-seem to call for special com¬ment are THE NEW FORM OF MAGAZINE MINING AND METALLURGY appeared every month during the calendar year and has been developed until it contains some ten departments It has brought forth more commendatory letters than have been received at headquarters on any other subject throughout the year Less than a dozen letters unfavorable to the change have been received, and the indications are that the magazine has met a want deeply felt, especially by members distant from headquarters The technical papers printed by the Institute are published in abstract in the magazine and opportunity is given to members who desire them to receive full copies of any or all papers published The Bound Volumes, as usual, contain all the papers in full and discussions thereof FINANCES The greatly increased cost of paper and printing has put a tremendous burden on the Institute's finances, since the dues of $12 per year are only 20 per cent greater than the members paid when the Institute was founded forty-nine years ago This has resulted in a temporary deficit, similar to that encountered by many of our sister engineering societies The fact that our Institute has lower dues and gives more in the way of publications to its members than any other of\the national engineering societies has rendered the situation more difficult for us MEETINGS The Annual Meeting in New York, the Field Meeting in the Lake Superior District, the meeting of the Petroleum and Gas members at St Lours, and of the Institute of Metals Division in Columbus, Ohio, have all been described in full in the magazine

Jan 1, 1923

By AIME AIME

FREE competition, long the controlling ideal of domestic trade within the United States, has had the fundamental geographical advantage of functioning in the world's largest area of unrestricted commerce. Goods moved back and forth across state lines, unimpeded by customs, and industrial operations have developed rapidly to meet the expanding needs of a pioneer country richly endowed with natural resources. Fifty years ago, antitrust laws were adopted to protect the competitive private enterprise principle. It became illegal for one person to combine with another to restrain trade or commerce among the several states or with foreign nations. The original legislative measures defining this philosophy were the Sherman Act of 1890 and the Clay- ton Act passed in 1914. The development of Europe and other parts of the world was influenced by different conditions which led to a different theory of trade. Here were many small nations, with limited natural resources and a thin market, and they attempted to protect their national economy by tariff walls. International business arrangements for the purpose of diminishing the ups and downs of the more competitive system --crux of the modern cartel operations-seemed a logical device to stabilize production and guard the interests of both workers and consumers. European governments as well as European industrial interests became convinced that if com- petition could be held in bounds the danger of business depressions and un- employment could be reduced.

Jan 1, 1944

By H. I. Aaronson, S. M. Kaufman, G. M. Pound

WHETHER the carbides associated with bainite precipitate from the ferritic component of bainite, as originally suggested by Davenport and Bain, or from the adjacent austenite at aus-tenite:ferrite boundaries, as proposed by Hultgren, 2 remains in dispute.3-5 A recent metallographic investigation in this laboratory has shown that the bainitic carbides formed in a plain carbon hypo-eutectoid steel nucleate entirely within ferrite at higher reaction temperatures3 and in both ferrite and austenite at lower temperatures." The present investigation was undertaken to ascertain the effects of alloying elements on the nucleation sites selected by bainitic carbides. The compositions of the steels studied were as shown in Table I. Specimens of these steels were

Jan 1, 1958

By R. E. H. Pomeroy

EARLY in 1917, it became evident, owing to existing and pending market conditions, that a substitute for crude petroleum must be found for firing the smelter furnaces. After a review of the plants then existing, it was deemed advisable to depart from their practice and to adopt the following described system of distributing pulverized coal to the furnaces. The principal advantages of the proposed system, which influenced this decision, were: (1) Equal safety; no pulverized coal is stored at the furnaces; (2) greater ease of operation, furnace fires being controlled by regulating valves in burner branches, as in gas firing; (3) better organization; all machinery, including pulverized coal feed, is under one roof, and the organization is separate from the furnace department; (4) greater cleanliness; all machinery is under vacuum; (5) greater flexibility of application; the coal and air mixture can be piped where needed. The design of the plant is the result of the combined efforts of the local engineering staff and of the machinery manufacturers. Many new features were embodied in this design to insure greater safety, cleanliness, and efficiency of handling. After 14 months of continuous operation, the plant has proved entirely satisfactory. The building is of structural steel, covered with corrugated steel, with many windows and is painted light gray inside and out. The building floor is of concrete with ample drains to the sewer, and the building is equipped with fire and service water piping. Fig. 1 shows the east side of the building and the incline conveyor from the raw-coal bins.

Jan 2, 1920

By R. O. Williams

Measurements have been made of the internal energy of deformation in a Cu-A1 alloy and a Cu-Zn alloy as the deference between the work and the released heat. The method required the rapid compression of samples to reduce thermal interactions. The rate of energy storage is low initially but then becomes almost linear with strain. Both alloys stored about 60 cal per mole at a strain of 0.4 in the recrystallized condition. The fractional rate of storage increases at low strains reaching about 0.25 at a strain of 0.15 and then decreases slowly with increasing strains. As do pure metals, these alloys release appreciable energy immediately following deformation; in contrast with pure metals, however, the release continued for extended periods of time. This energy release is somewhat sensitive to the amount of deformation, the deformation temperature, and prior thermal & eatment. It is believed that this release is a composite of that observed in pure metals which has been attributed to dislocations and that due to the motion of vacancies which produces increased short-range order. IT is expected that changes brought about by deformation of a pure metal can be understood in terms of the three defects—dislocations, vacancies, and interstitials—along with the interactions possible between these defects. Frequently stacking faults are created and must also be considered. 1t is not immediately clear whether or not the stress fields which are created should be regarded as independent of dislocations. For alloys there is the important additional effect of atomic configuration, for example short-range order, which must also be considered and will, in general, interact with each of the above defects. While it is true that a complete understanding of pure metals is not yet possible, it would seem very valuable to establish the similarities and differences between pure metals and alloys. Such knowledge could contribute to the understanding of both. A study of the changes in internal energy resulting from deformation of two alloys is reported here. Although some information has been available for alloys almost as long as for pure metals, the volume of work has been substantially less. Sato' and Quinney and Taylor' were responsible for the earlier work, both using brass and annealing calorimetry. tizhnova' studied stored energy in Cu-Ni alloys by a method somewhat similar to the one reported here. Bever and his co-workers have made extensive studies of Au-Ag alloys4'5 and more recently CU-AU'U' using solution calorimetry. Clarebrough et a1.' have recently studied brass using annealing calorimetry. EXPERIMENTAL METHOD The present results were obtained by the rapid, adiabatic compression of a sample about 1/4 in, diam by 1/2 in. long between two tungsten carbide hammers. A vacuum provided thermal isolation and oil provided effective lubrication between the sample and hammers. The increase in internal energy is the difference between the mechanical energy and the heat liberated within the sample. The mechanical energy was determined from the velocity of the hammers (calculated from the height through which the hammers traveled) and was essentially constant for each deformation cycle. The heat was determined from the temperature increase of the sample which was measured by an embedded thermocouple. Specific heat data were calculated from Neumann's rule using tabulated data for pure metals.9 Since the fraction of the energy which is stored is large compared to that for pure metals, specific heat data of high accuracy are not required. Successive increments of deformation were carried out by repeating the procedure, the limit being determined mostly by the decreasing accuracy caused by the increasing corrections and the decreasing storage of energy. About five cycles were used to give a true strain of about 0.5 while the time interval between cycles was 1 to 2hr.

Jan 1, 1963

By Louis A. Panek

Ground movements in the zone adjoining an active cave were measured at four sites in the San Manuel Mine. Measurements were made to detect extension and inclination, basic components of displacement, which can readily be duplicated by mine personnel using relatively simple equipment. The displacements demonstrated the development of a zone of strain relief surrounding the active cave, within which the ground tends to migrate toward the cave, and extension cracks develop tangential to the cave. This expansion of the ground surrounding an active cave can be exploited to promote future caving; it also creates special problems with respect to the design of an effective ground support system for mine openings in the production area.

Jan 1, 1981

By R. J. Greaves

High-resolution seismic reflection profiling can be used to evaluate detailed structural and stratigraphic features of coal prospects. Since most coal prospects are relatively shallow, less than 1000 m (3000 ft) deep, high sampling rates in space and time can be used effectively to improve vertical and lateral resolution of seismic data. The case study presented here shows how seismic data was used to evaluate the Wyodak coal at a prospective coal gasification site. The data were used to map the detailed structure and thickness of the coal and to search for lateral discontinuities, such as pinchouts and faults. An important find was a paleochannel cutting across the base of the coal seam, which was later confirmed by drilling.

Jan 1, 1986

By Robert H. Hafner, Irvin R. Kramer

IN recent years considerable interest has been shown in surface-alloyed metals, particularly those of chromium (chromized steels), which have excellent corrosion [ ] resistance under a variety of severe conditions, and may undergo bending and flanging operations without spalling. An early method' employed to produce a high-chromium case on steel was developed by Kelley in 1921. It consisted of heating a low-carbon steel in intimate contact with powdered chromium in the presence of hydrogen at temperatures sufficiently high to permit diffusion of chromium into the steel. The usefulness of this process was limited because the extremely high temperatures of 1200° to 1400°C. (2200° to 2550 F.) caused excessive grain growth and warpage. Louenstein and Ulmer2 packed iron castings in ferrochromium and com- [ ] mon salt, and heated for approximately three hours at 930° to 1040°C. (1700° to 1900°F.). A recent and more practical method of depositing chromium on steel surfaces has been developed in Germany by Daeves, Becker and Steinberg3-8 and in Russia by Izgaryshev and Sarkisov.9 This process consists of passing gaseous chromium chloride over the steel to be chromized at temperatures of 900° to 1000°C., or packing them in a porous, ceramic material that previously had been saturated with chromium chloride. They reported obtaining a chromized layer, 0.004 in. thick, on low-carbon steels. Later, Daeves4 established a relationship between the carbon content

Jan 1, 1942

By Yves Dardel

THE literature concerning the remelting of aluminum and its alloys is very rich. Unfortunately the greater part of the papers about this subject have no scientific value, for the theories or explanations are too often in opposition to the laws of physical chemistry. Furthermore only a few of the methods of purification1,2 are considered in the literature. Hence it has seemed necessary to the author to sketch a general theory of the purification of secondary aluminum. The purpose of the purification is to eliminate the impurities that the charges and the atmosphere of the furnaces bring into the bath during the successive remeltings. Indeed scrap as well as metal can be used when soiled with oil, greases, water, .. , if it has been sufficiently dried and contains oxides. At the melting point of the metal, the oils and greases are decomposed into their constituent elements H2, 02, H2O, C02, CO, CH4, and others. These gases are added to the corresponding gases in the atmosphere of the furnace. The impurities introduced into the metal during the remelting will accordingly be the products resulting from the action of these gases on the liquid bath. The quantity of hydrogen that is soluble in aluminum and its alloys is given by the relation of Sieverts3 as a function of its partial pressure PH2 in the atmosphere [m = K _%/PH, [I]] where K is a constant, which depends only upon the temperature and increases with it. The experiments of Röntgen and Braun4, Röntgen and Möller5, Bircumshaw6 and Winterhager7 have rendered it possible to determine the value of K, when the temperature is inferior to 1.000°K. One obtains: [log K = - 4,702.5 + 0.238 [2]] Besides its usual signification, the term PH2 represents also the internal pressure of dissolved hydrogen, since in the equilibrium, that is, when no gas exchange occurs between the two phases, the pressures of hydrogen in the metal and in the atmosphere must be equal. Eq I shows that when the partial pressure of H2 increases the amount of dissolved hydrogen in equilibrium increases, and that, if the contrary occurs, the quantity of H2 should diminish. However, if for any reason the diffusion of hydrogen is hindered and the total amount of dissolved gas remains constant while the temperature lowers, the internal pressure of H2 increases until it reaches the value of the hydrostatic pressure. At this point, bubbles of hydrogen appear in the bath and escape out of it. The amount of hydrogen in the metal is then limited by a maximum depending on the hydrostatic pressure, which is practically equal to one atmosphere. Indeed hydrogen does not accumulate in the form of a hydride appearing as a separate solid phase. However, even the mechanism of the solubility is not yet elucidated. One does not know exactly as yet, whether the

Jan 1, 1947

By F. D. Rosi, C. A. Dube, B. H. Alexander

WHEN a deformed polpcrystalline metal is heated to a sufficiently high temperature, a recrystallized structure develops which consists of small, essentially stress-free grains. This transformation is referred to as primary recrystallization. Under certain conditions, on prolonged annealing of the specimens, a type of grain coarsening occurs in which a small number of grains commence to grow at various points by devouring the neighboring finegrained primary structure, which, in itself, exhibits a marked stability toward normal grain growth. This grain coarsening process has been referred to by Burgers' as "secondary recrystallization" or "exaggerated grain growth." Although much work has been done on recrystallization and growth processes, present knowledge of the factors which determine the occurrence and growth of secondary grains is inadequate for the advancement of a theory which accounts for the observed characteristics of this recrystallization phenomenon. In this respect, it would be important to make measurements of the velocity of growth of these large secondary grains. The early work of Feitnecht2 on aluminum showed that the size of secondary grains increased with temperature and time, suggesting that such measurements would be possible. More recently, Burgers1 found that the growth velocity of these grains in aluminum was constant over a large time interval, as is generally found for the growth velocity of primary grains in a uniformly deformed test piece.3-5 It is reasonable to expect that the determination of the activation energy of the secondary growth process might lead to a better understanding of the underlying atomic mechanism. This investigation, therefore, is one of a series primarily designed to measure the growth velocity of secondary grains at various temperatures for silver, copper, and aluminum. It is hoped that these studies along with those of orientation relationships, will establish a sound basis for theorizing as to the origin and nature of the secondary transformation. Experimental Procedure The metal used in the present investigation was high-purity silver (999.9 fine), which was supplied in the form of cold-rolled plates 0.250 in. thick. These plates were annealed at 500°C for 1 hr and then straight-rolled to a thickness of 0.04 in. in three reductions of approximately 45 pct, followed in each case by an anneal at 450°C for 1/2 hr. The 0.04 in. sheets were given a final reduction of approximately 50 pct, which resulted in a thickness of 0.02 in., thereby insuring two-dimensional crystal growth. Individual specimens of this material about 1x3 cm were used for all heat treatments, unless otherwise noted. The annealing was carried out under an atmosphere of argon in an Inconel tube furnace whose temperature was controlled to within -+2°C. Metallographic examination of the secondary transformation was accomplished by mechanically polishing the specimens on one side to approximately one half their thickness through 2/0 metallographic emery paper, and then electrolytically polishing in a solution of potassium ferrocyanide and sodium cyanide. With a current density of approximately 20 amp per sq dm, the time required to obtain a satisfactory surface varied from 3 to 5 min. Standard potassium bichromate was used to etch the electrolytically polished surfaces. A heavy etch with this solution produced a sharp contrast between the secondary grains and the fine-grained primary structure, darkening the latter while leaving the large secondary grains bright. All area measurements of the secondary crystals were made with a planimeter on enlarged tracings of the grains.

Jan 1, 1953

By M. C. Flemings, T. S. Piwonka

Pore formation is examined analytically in cellu-larly solidified single crystals, in cylindrical castings of pure metals and alloys, and in unidirectionally solidified castings. Effects are considered of fluid flow. dissolved gas, and surface tension. Experimental results show that flow through a partially solid "mushy" aluminum alloy obeys relations similar to those applicable for flow through other types of porous beds. Flow rate is proportional to the square of the fraction liquid (fL) for fL less than 0.3. Results indicate models chosen for mathematical description of pore formation in alloy solidification are valid. ONE of the solidification variables which is influential in determining mechanical properties of castings and of wrought material produced from cast ingots is porosity. This porosity may result from shrinkage, dissolved gases, or a combination of both, and may take the form of either macroscopic pores in localized areas of the casting or microporosity evenly distributed throughout large areas of the casting. In alloys which freeze over a range of temperatures some microporosity is generally found after solidification. There has been much discussion as to whether the micropores are caused primarily by shrinkage, by gas, or by a combination of both.'-3 There has, however, been little experimental or analytical work performed to delineate the relative contributions of shrinkage and gas in causing microporosity or to quantitatively describe the influence of processing variables on microporosity. Porosity other than microporosity (e.g., center line shrinkage) has also received only limited quantitative treatment.495 The aim of this work is to examine analytically the general problem of pore formation in solidification and to perform limited confirmatory experiments. Consideration is first given to shrinkage porosity in pure and nearly pure metals (shrinkage in cellular growth, centerline shrinkage in cylinders). Next, a discussion is given of formation of shrinkage-caused microporosity in unidirectional solidification and in "mushy" solidification. Finally, influences of dissolved gas and surface tension on microporosity are examined. Numerical results are given for aluminum and an aluminum alloy. Typical examples of microporosity are shown in Figs. 1 to 3, for 1) cellularly solidified aluminum, 2) sand-cast aluminum alloy, and 3) low alloy steel. SHRINKAGE POROSITY IN PURE AND NEARLY PURE METALS 1) Cellular Growth. In cellular freezing of an impure liquid, liquid grooves may exist over a considerable length of the growing crystal.6 The cross-sectional area of the grooves decreases with increasing distance from the cell tips; the root of the groove is blunt if the liquid at this point reaches eutectic composition. As a result of volume contraction during solidification, flow occurs down the groove, parallel to the growth direction; hence, there must be a pressure drop from the groove entrance to points within the groove. The geometry of the groove is simplified to that of a circular cylinder of radius r and length L, Fig. 4, L » r, and a simple and useful limiting case is obtained. This is that, in the circular cylinder freezing at constant velocity, the pressure at the root of the groove is lower than that pressure at radius r in grooves of other geometries where r decreases continuously to a lower limit at L. As discussed below, a pore resulting from a given pressure difference

Jan 1, 1967

By T. H. Alden

Using alternating tension-compression straining, the hardening of magnesium oxide single crystals was studied up to large stresses and strains. At 0.25 pct plastic strain amplitude, the hardening curve is approximately linear with slope 25,000 psi from the shear yield stress, 7 to 8000 psi, to 35,000psi. Above this stress, the slope decreases. The strain hardening behavior of MgO is considered qualitatively similar to that of metal single crystals. The relatively high stress attainable by strain hardening is associated apparently with the high yield stress on the cross-slip system, (001) <110>. Cleavage fracture during testing is uncommon. It is argued that the centers of high internal stress at glide band intersections, at which cracks tend to nucleate, are dispersed by cyclic strain. Special features of the glide band structure produced by cyclic strain and revealed by dislocation etch pits, support this view. Strain hardened MgO has mechanical properties greatly superior to the as-received material: yield stress, greater than 100,000 psi; elongation to fracture about 1 pct. A material is said to strain harden if the yield stress increases with an increment of plastic strain. This definition is usually applied for straining done in one direction, but is also applicable when the strain direction is periodically reversed, Fig. 1. For certain metal single crystals, data are available which permit a comparison of the hardening behavior for cyclic straining and for tension straining.&apos;-4 With certain qualifications, these data show that the same processes of hardening are operative in each type of test.5 Despite this fact, the importance of the technique is not immediately evident, although tension-compression studies of the common metals appear to suggest some deficiencies in theories of strain hardening developed exclusively on the basis of tensile tests. However, a recent observation suggests that the cyclic straining method may be very useful for studying semibrittle crystals in which large plastic strains are not accessible in unidirectional testing. The observation is that zinc crystals, when strained in tension-compression at -52°C, do not fail by cleavage at low stress (-500 psi)6 as they do in tension, but harden to a limiting stress of more than 5000 psi over a total plastic strain of about 600 pct.2 An important characteristic of the behavior of zinc crystals is the high stress, relative to the yield stress, attainable by strain hardening. By comparison, the hardening of aluminum single crystals tested by an identical technique saturates at 1100 psi. This difference is best explained by the cross-slip hypothesis of dynamic recovery.7,8 In zinc, cross slip is difficult because of the high yield stress for glide on planes other than the basal plane in the < 1120 > zone. The present work was undertaken in order to test whether these methods and ideas are applicable to other materials. Magnesium oxide single crystals, in common with most crystals of the rock-salt structure, deform plastically but fail by cleavage after a small strain when tested in tension. It was hoped that larger strains would be attained using tension-compression. There is, in addition, evidence 8a which shows that slip on the probable cross system, (001) < 110>, is difficult in magnesium oxide; it may therefore be possible to attain high stresses by strain hardening. 1) EXPERIMENTAL PROCEDURE Experimental methods used in this study were based in part on techniques reported in papers of Stokes, Johnston, and Li.&apos; MgO blocks, purchased from Norton Co., were used without further annealing. Specimens were cleaved to dimensions approximately 0.125 in. sq and 1 in. in length. The gage section, formed by chemical polishing, was sprinkled with 280 mesh silicon carbide particles in order to introduce fresh dislocations. The crystals were then cemented into cylindrical aluminum adapters and clamped in an Instron testing machine. One of two alternating straining programs was used. In the first, total cross-head travel was established and increased in steps after various numbers of cycles. In the second, a capacitance gage was used to directly measure the elongation of the specimen and the crosshead was controlled so as to keep the plastic strain amplitude constant. The straining was always symmetrical with respect to the initial, zero strain condition. While both procedures produce strain hardening, only the latter permits a measure of the total plastic strain so that hardening curves may be drawn. Constant plastic strain amplitude tests were done

Jan 1, 1963

By Edward Keller

THE ASSAY FOR COPPER. SOMEONE some time ago remarked that some chemists still insist on telling us how to determine copper by the electrolytic method. The. writer must confess that he believes that everything is not known definitely as yet as to how the exact amount of copper is determined in such material as purest commercial electrolytic copper. Some of us are not yet convinced that the pure copper atom is at all times deposited from an acid solution and that no oxygen or hydrogen will, under certain conditions, accompany it. Difficulties with impurer material are frequent, but erroneous results are not always apparent, since these do not speak so readily for themselves as those in the first case. By this is meant that if a chemist finds 100 per cent. of copper in electrolytic copper it is pretty certain that he perceives the result to be wrong, while if he finds 0.1 per cent. of copper too much in a very impure material he is far more likely to be unconscious of his error. These, in a wide experience, are frequent happenings and the writer has always looked with interest to publications on this subject. In turn, he :feels justified in giving to others a few of his own observations. Up to a few years ago there were two methods of electrolytic copper assay in technical use, which had in common, that the amount of copper deposited on the cathode did not exceed 2 g., and they differed in that, for the one a large sample 1 (20 to 80 g.) was taken from the general sample by a splitting device, dissolved, and from the solution a small portion (to contain 1 or 2, g. of copper) measured out for the electrolytic deposition; in the other Method the copper was determined, generally in 1-g. portions of the separated coarse and fine portions of the sample, all of which passed -a 16 or 20-mesh screen, being accomplished by a 40-mesh screen,

Jan 8, 1913

By M. S. Rashid, C. J. Altstetter

Allotropic transformations in cerium have been studied by dilatometric, resistometric, X-ray diffraction, and metallographic techniques. The dilatometric study indicated that, on cooling below O°C, the high-temperature fcc phase, y, transforms partly to the hexagonal phase, ß, and, on further cooling, to the collapsed fcc phase, a. The amount of $ phase present at room temperature is increased by repeated cycling through the a-y transformation. It has been shown metallograPhically that the y-ß transformation has many characteristics of a martensitic transformation. In contrast to the y-ß transformation the ?-a transformation does not give the manifestation of a shear transformation. Small cellular ? domains of random shape and size collapse to a in a short time with no apparent coordination with neighboring domains. The considerable confusion in the literature over the existence of more than one high-temperature fcc phase is discussed. Two such phases have been reported in the literature and an attempt is made in this study to clarify the situation. Twelve fcc and two hcp structures have been shown to be easily reproduced or eliminated. It is proposed that the two "additional" allotropes reported in the literature and fourteen of the phases detected here are not allotropes of cerium but are due to contamination. CERIUM exists in several allotropic forms, but there is some disagreement over what the forms are. Furthermore, the conditions favoring the presence of a particular allotrope and the nature of the transformations from one form to another are uncertain. The objectives of this research were 1) to ascertain the allotropic forms of cerium, 2) to establish the conditions under which the allotropes exist, 3) to study the effects of annealing and thermal cycling on the allotropic transformations, and 4) to study the transformation mechanisms. Dilatometric, resistometric, metallographic, and X-ray diffraction techniques were employed. The form of cerium commonly found at room temperature is fcc and is designated ?. A complex hexagonal phase, 8, forms when y is cooled to slightly below room temperature. At still lower temperatures the y fcc structure transforms to an fcc form with a much smaller lattice parameter, termed a cerium. A bcc form, 6, which exists just below the melting point (800°C), will not be considered further in this work. There is a substantial body of experimental evidence (reviewed by Gschneidnerl) which favors the acceptance of these four allotropes, though some investigators have tried unsuccessfully to observe the ß hexagonal form.&apos;-&apos; There is disagreement, however, over the phase-transformation temperatures, due, in part, to broad hysteresis and overlapping of the transformations between the a, ß, and ? forms. The transformations are also sensitive to prior thermal and mechanical treatment. The differing purity of cerium used by different investigators is undoubtedly a factor. Cerium is difficult to separate from other elements and is quite reactive, igniting spontaneously when it is filed in air. The highest purity of cerium to date is reported to contain several hundred parts per million by weight of impurities, and early investigations were carried out on cerium containing several percent of impurities. There have been reports of more than one fcc allotrope at room temperature. Gschneidner, Elliott, and McDonald5 obtained diffraction patterns of an fcc phase with a lattice parameter about 1 pct less than that of the ? phase, instead of the y phase, on slowly cooling cerium filings from 23° to -198°C and warming them back to room temperature. However, when the sample was heated to 447°C and cooled to room temperature it consisted of only the ? phase. They have designated this new fcc phase "a-? intermediate", and say it is quite sensitive to impurities. After prolonged high-temperature treatment of a powder specimen, Weiner and Raynor2 obtained a diffraction pattern of an fcc phase of lattice parameter about 1 pct less than the ? phase. This they called the y&apos; phase. It could not be reconverted to the y phase and is claimed to be different from the a-? intermediate phase.5,6 Dialer and Rothe3 reported two fcc phases* after cycling their powder specimens between room temperature and -192°C. Gschneidner, Elliott, and McDonald5 suggested that one of the fcc structures obtained by Dialer and Rothe was equivalent to their "a-? intermediate" phase. Table I presents some pertinent data on the proposed allotropes. For the ?(fcc)-ß(hexagonal) transformation

Jan 1, 1967

By George Enos

As the coating formed affects the corrosion rate, duplicate samples of eight non-ferrous alloys were placed in flowing mine water. The alloys tested were as-cast or as-rolled and machined or polished. The paper describes the tests and gives the corrosion losses and the appearance of the samples at the end of the test. AN IMPORTANT factor affecting the rate and nature of corrosion of metals and alloys is the film, or coating, formed on the surface; and this may accelerate or retard corrosive action once started. The formation of films and coatings is intimately associated with the chemical composition and physical constitution of both the metal and the corroding medium. A film or coating may be either the corrosion product resulting from oxidation; that is, an oxide or salt, or a deposition of suspended matter from the corroding media upon the surface of the metal, or a mixture of both. The coating may adhere tightly or loosely to the surface of the corroded metal. In short, a film or coating is the reaction product of the corroding medium and the metal, which adheres to the surface of the metal and with which may be intermingled material from the attacking media not concerned in the chemical reactions. As the, terms film and coating are used by different writers for very different things, distinction is made between the two, by the present writers, on the basis of thickness. Thus, a film is defined as a corrosion product or deposition, on the surface of a corroded metal, that is of such thickness that it cannot be measured by the metallurgical microscope. A coating, on the other hand, is of such thickness that it can be measured. If the resolving power of the 2 mm. (equivalent focal length) apochromatic oil immersion objective (N.A. 1.4) is taken as the limit of the microscope, the limiting resolution is two lines that are 0.0002-0.0004 mm. apart. It is thus possible to measure coatings that are greater than 0.0002-0.0004 mm. thick. This thickness is equivalent to 200,000-

Jan 7, 1924

By William Hurst

This is a presentation of the diffusivity theory for the calculation of the water drive on an oil reservoir in which the history of reservoir pressure with time are the essential parameters for the determination of the rate and cumulative water encroachment into a field. The main body of the paper is essentially the application of the principles underlined here to actual field data. It consists of the work plots of the radial-flow case, and includes a discussion of an illustrated problem for which the water-drive calculations are treated in conjunction with the volumetric-balance equation. The appendix is a mathematical treatment of the linear, radial, and spherical cases of water influx into a reservoir. Introduction The evaluation of oil reserves and the prediction of pressure behavior with different rates of production are related to the volumetric balance of the fluids entering and leaving the space occupied by the oil and gas originally present in the formation; that is to say, important information can be gleaned from a volumetric study of the oil, gas, and water produced from a formation as it affects the extent of change in volume of oil zone, the gas cap, and the amount of water influx from the adjoining water sands. It is not the purpose of this paper to enter into a discussion of the equation of volumetric balance, in which such pertinent information as subsurface sampling and the measurement of reservoir pressures play a predominant part, as this has been discussed in detail by others.1,2 However, there is an inherent difficulty that has limited the general application of this equation to a study of oil reservoirs; that is, the insufficient knowledge of the analytics for expressing the water drive on a field as a function of reservoir pressure. This to a large degree has been overcome and it is the purpose of this paper to present this theory in such form as to be applicable for reservoir calculations. Water Drive If the amount of oil originally in place and the gas space are known, it is a relatively simple matter to determine, by the volumetric equation, the cumulative water influx into a reservoir from the adjoining water sands. Often, however, the oil reserve as well as water influx must be &apos;determined, and in order to be able to make this calculation it is essential to assign a mathematical relationship for the varying water term that is compatible with conditions known to exist in the formation and gives an accuracy acceptable for engineering calculations. Various equations have been employed empirically by different investigators in making reservoir studies of water drive. One form used by Schilthuis2 expresses the rate of water influx into a reservoir at any time as proportional to the pressure

Jan 1, 1943

By William Hurst

This is a presentation of the diffusivity theory for the calculation of the water drive on an oil reservoir in which the history of reservoir pressure with time are the essential parameters for the determination of the rate and cumulative water encroachment into a field. The main body of the paper is essentially the application of the principles underlined here to actual field data. It consists of the work plots of the radial-flow case, and includes a discussion of an illustrated problem for which the water-drive calculations are treated in conjunction with the volumetric-balance equation. The appendix is a mathematical treatment of the linear, radial, and spherical cases of water influx into a reservoir. Introduction The evaluation of oil reserves and the prediction of pressure behavior with different rates of production are related to the volumetric balance of the fluids entering and leaving the space occupied by the oil and gas originally present in the formation; that is to say, important information can be gleaned from a volumetric study of the oil, gas, and water produced from a formation as it affects the extent of change in volume of oil zone, the gas cap, and the amount of water influx from the adjoining water sands. It is not the purpose of this paper to enter into a discussion of the equation of volumetric balance, in which such pertinent information as subsurface sampling and the measurement of reservoir pressures play a predominant part, as this has been discussed in detail by others.1,2 However, there is an inherent difficulty that has limited the general application of this equation to a study of oil reservoirs; that is, the insufficient knowledge of the analytics for expressing the water drive on a field as a function of reservoir pressure. This to a large degree has been overcome and it is the purpose of this paper to present this theory in such form as to be applicable for reservoir calculations. Water Drive If the amount of oil originally in place and the gas space are known, it is a relatively simple matter to determine, by the volumetric equation, the cumulative water influx into a reservoir from the adjoining water sands. Often, however, the oil reserve as well as water influx must be &apos;determined, and in order to be able to make this calculation it is essential to assign a mathematical relationship for the varying water term that is compatible with conditions known to exist in the formation and gives an accuracy acceptable for engineering calculations. Various equations have been employed empirically by different investigators in making reservoir studies of water drive. One form used by Schilthuis2 expresses the rate of water influx into a reservoir at any time as proportional to the pressure

Jan 1, 1943

By Arthur Knapp

No oil territory in the world has been so rich in large producing wells, in a comparatively small area, as the Baku field. Particularly is this true of the Bibi Eibat field, which formerly produced millions of "poods," of " gusher," or as it is called in Russia, " fountain " oil. The Bibi Eibat and Balachany fields have been exhausted of gas and ruined by water, but the Surachany and Benegadi fields are still fountain territories and many outlying districts that have only been prospected produce rich fountains. The method of controlling fountains, or gushers, is the result of growth, along with the Russian system of drilling, where large diameters and riveted casing have been in vogue. The screw casing is seldom used except to exclude water. Formerly the method of finishing wells and the condition of the casing at the top of the well would not permit the use of gates, manifolds, and connections as is standard elsewhere. The life of the flowing wells is very short, particularly those 10 in. (25 cm.) or more in diameter, which produce large quantities of sand and often flow for but a few days and are then a complete loss. More than 1,000,000 poods in 24 hr. have been claimed in several instances, but in no case was the flow for more than a few days. The oil sands of this district are free uncemented sands and vary in thickness from paper thin to a maximum of 10 ft. (3 m.). The sands are interlaid with strata of soft clay. In spite of this, the practice has been to drill into such sands and produce from the open hole without screen or liners. Sometimes the casing is set below the oil sand but in this case holes from 2 ½ to 3 in. in diameter are drilled opposite the oil sand, which would not have the effect of a screen.

Jan 1, 1920