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By J. D. Wheeler, H. W. Mathews

The increased activity in West Texas, which started in 1933, has continued through 1936 at a constantly accelerated rate. During 1936 there were 1442 wells completed in the area as compared with 700 in 1935 and 468 in 1934. Of these completions, 1313 were producers with a total 24-hr. potential in excess of 1,750,000 bbl. From among the 1442 wells, eight are considered to be discovery wells for new West Texas fields. New Fields Bennett.—The Bennett field, which added Yoakum County to the oil-producing counties of West Texas, was actually indicated as an oil-producing area during 1935, but the discovery well, Honolulu Oil Corporation, Ltd. and Cascade Petroleum Company's Bennett No. l, was not given a production test until April 1936. The discovery well made 15 bbl. per hour through 3/4-in. choke with a plugged-back total depth of 5264 ft. First oil in the hole was from 5088 to 5090 ft., which is several hundred feet below the top of Permian lime. Producing limits of the field are unknown, as the second test had not reached the pay at the close of the year. Henderson.—-To date indications are that the Henderson pool, in northern Winkler County, is the most prolific area opened during 1936. This field, which lies to the north of the old Hendrick pool, is producing from the same reef-type dolomitic lime producing in the older field. The Henderson field was opened by the completion of R. H. Henderson, J. B. Walton-Humble 1-A in April 1936 for a natural flow of 2306 bbl. per day through tubing. Total depth of the discovery well is 3049 ft. Later development has indicated the productive area to be a rather narrow zone running slightly west of north. Present area of from 1000 to 1500 acres has been proved for production. Keys and Emperor.—The Keys and Emperor pools in the belt of sand pools running across Winkler County appeared for the first time on State proration schedules during 1936. This report considers these pools as links in joining the belt of sand production across Winkler County, for

Jan 1, 1937

By James W. Dally, William L. Fourney, Anders Ladegaard Peterson

For the past 3 years, the authors have been conducting research sponsored by the National Science Foundation (RANN) to improve the process of excavation by drilling and blasting. The approach followed has been experimental where the development of stress waves and fractures initiated at the bore hole have been investigated in order to obtain a complete understanding of the dynamic Fracture process. The second step in the approach has been to introduce modifications in the drill and blast procedure which will permit closer control of the fracture process.

Jan 2, 1978

By J. A. B. Forster

The operations of the Electrolytic Zinc Co. of Australasia Ltd. involve the preliminary roasting of zinc concentrate from Broken Hill, New South wales, at a number of acid-making centers on the Australian mainland. The partially roasted material is shipped to the Tasmanian plant where it was formerly re-roasted prior to leaching,' but this practice was gradually abandoned in favor of the flotation of leach residue for the recovery of a concentrate containing about 22 pct sulphide sulphur and known as secontlary or Risdon concentrate.2 This change, together with increased zinc production, called for new furnaces at Risdon for the roasting of 10-50 tonst of secondary concentrcite and 90 tons of new concentrate per day. The war situation made it imperative that construction be commenced without delay and to save time it was decided to base the design on that of Skinner type furnaces which had been built in South Australia twenty years earlier. This involved some sacrifice of desirable features but did not prevent the incorporation of provisions which had enabled small Herreshoff type furnaces to roast secondary concentrate autogenously. The roasting rate in existing furnaces was 10-12 Ib sulphide sulphur per sq ft of hearth area per day, and eleven hearths, 20 ft in diam, were provided in the two new furnaces in anticipation that they would prove capable of the autogenous roasting of 130-140 tons of concentrate per day from 28-29 pct sulphur down to 4.5-5 pct, with an oxidation rate of 11-11.5 lh S/S per sq ft of hearth area per day. It was soon realized, when the first of the furnaces went into operation, that a much better performance than this might be given, and the purpose of this paper is to show how a treatment rate of 100 tons per furnace day, and oxidation rates approaching 15 lb S/S per sq ft per day have been reached. Furnace Design General specifications for the design were based on the results of experience with several other types of furnace and on the special operating conditions

Jan 1, 1950

By Fred J. Hurst

In 1934, Irvin Lavine (A), University of North Dakota, stated that the low-rank coals (lignite and subbituminous) of this country represent a vast tonnage of fuel of commercial value and predicted that some day they will play an important role in our economic welfare. Lavine also pointed out that one of the major problems with efficient utilization of the low-rank coals is their high moisture content. Following the discovery of uranium-bearing lignite in the Williston basin of North and South Dakota in 1948 by D. G. Wyant and E. P. Beroni, detailed investigations were conducted (primarily during 1950 to 1954) by members of the U. S. Geological Survey to evaluate the geologic factors and economic possibilities of the radioactive lignites as a source of uranium. The information gained in these studies and summarized in several papers indicated that a large potential reserve of uranium is contained in the subbituminous coal and lignite deposits of the Dakotas and Wyoming (2,3,4). Most investigators concluded that an epigenetic emplacement of uranium in the coal by means of circulating groundwater and the more extensive concentrations of uranium in coal are apparently related to the permeability of the rocks enclosing the coal beds. Breger (5) and others have shown that uranium is readily adsorbed by coal and is held irreversibly as a disseminated adsorbed constituent. Briefly, lignite beds containing 0.1 to 10% uranium have been discovered in the Dakotas and Wyoming. The distribution of uranium was found to be erratic and was usually concentrated in thin layers, which were characteristically 10 to 14 in. thick and occasionally 30 to 36 in. thick. Lignite beds more than 3 ft. thick generally contain more uranium at the top of the bed than at the bottom. Special strip mining techniques are required to mine these thin

Jan 1, 1983

By J. W. Downey, M. V. Nevitt

The phase boundaries for the 950" isothermal sections in the ternary systems Zr-Co-0 and `Zr-Ni-0 have been determined for the composition range from 50 to 100 at. pct Zr. The two systems show very similar phase relations, having no extensive solid solution phase fields. Each contains a ternary phase. These phases are apparently isostructural, but their structure has not been determined. Some aspects of the phase relations are discussed in terms of the alloying behavior of transition metals. THE work described in this paper is the outgrowth of a recent study of the occurrence of phases having the Ti2Ni-type structure (structure-type E9,) in certain ternary systems involving Ti, Zr, or Hf with another transition metal and O.", In the Zr-CO-0 and Zr-Ni-0 systems no Ti2Ni-type phases were found to occur. However, there are several interesting aspects of the phase relations in the two systems which have significance from the point of view of the alloying behavior of transition metals. The results of this investigation may also have some importance in studies of the oxidation of Zr-Co and Zr-Ni alloys. In both the Zr-Co-0 and Zr-Ni-0 systems only the 950" isothermal sections were investigated and, as a further restriction, the study was limited to the composition range from 50 to 100 at. pct Zr. A tentative Zr-Co binary diagram has been published by Larsen, Williams, and Pehin. In the composition range pertinent to the present work they report a eutectic at 980°C and 75.9 at. pct Zr, the products of which are the terminal solid solution based on /3 Zr and the compound Zr2Co, and a eutectic at 1080" and 64.8 at. pct Zr whose products are Zr,Co and ZrCo. The solid solution based on /3 Zr is shown to decompose eutectoidally at 826°C into a Zr and Zr2Co. The limits of solubility of Co in a and /3 Zr have not been established. The structure of Zr2Co is not identified in the publication just cited. Dwight has reported that ZrCo has the CsC1-type strcture. The Zr-rich portion of the Zr-Ni diagram has been determined by Hayes, Roberson, and Paasche." The phase relations are very similar to those of the ZrCo system. A eutectic reaction whose products are /3 Zr containing 2.9 at. pct Ni and Zr,Ni occurs at 961°c, and a eutectic between Zr,Ni and ZrNi is found at 985". The solid solution based on /3 Zr decomposes eutectoidally at 808°C. The solubility of Ni in a Zr is not known accurately but is believed to be very small. Smith, Kirkpatrick, Bailey, and Williams7 have found that Zr2Ni has a tetragonal structure of the A1,Cu-type and that ZrNi is orthorhombic. Domagala and McPherson8 have published a constitution diagram for the system Zr-ZrO,. At 950" their diagram indicates that the solid solution of 0 in 0 Zr is stable from 0 to 0.5 at. pct while the phase field of 0 in a Zr extends from 6 to 29 at. pct. These solubility limits were adopted in the present study and no binary Zr-0 alloys were made. No previous data on the phase diagrams of the ternary systems are known to exist. EXPERIMENTAL PROCEDURE The experimental details involved in the preparation of alloys in this laboratory by arc melting have been described in several previous papers"3 and they will not be repeated here. Information concerning the purity of the metals used is given in Table I. Oxygen was added in the form of reagent grade ZrO,. All of the cast specimens in both alloy systems were annealed in air-atmosphere tube furnaces at 950 3' for 72 hr and water quenched. The specimens were protected from oxidation by wrapping them in Mo foil and sealing them in quartz tubes that had been evacuated at room temperature to a pressure of 1 x 10B mm of Hg. The phase boundaries were determined by metallography, and identification of the phases was accomplished primarily by X-ray diffraction methods which employed a powder camera having a diameter of 114.6 mm. The diffraction techniques which are in use in this laboratory have been previously described.' An etchant that proved satisfactory for most of the alloys consisted of 5 pct by vol of AgNO

Jan 1, 1962

By Raymond S. Weimer

Of the several characteristics of a coal that influence its suitability for use in a given piece of burning equipment, the clinkering and slagging characteristics of the ash of the coal are highly important. They determine the maximum rate at which the coal may be burned on a stoker or in pulverized form without difficulty from damage to metal parts, from erosion of refractory walls, or from stoppage of gas passages by accumulation on the tubes. They also determine the minimum rate at which a slag-tap furnace may be operated without difficulty in removal of the ash in fluid form. Need for a Better Criterion In common with other producers and users of coal, the Northern Illinois Coal Corporation has long used the available methods for the measurement of the clinkering characteristics of coal ash, chemical composition and fusion temperature of the ash, as criteria for the selection of coal that would suit the particular requirements of its customers. These two available criteria have greatly helped in the problem of selection but it is unnecessary to dwell upon the fact that they are not completely adequate for the purpose. The composition of the ash and its clinkering tendency vary widely over the company's mining area. In a certain period, some years ago, an unusual amount of severe clinkering of the ash of coal shipped made extremely acute the need for a better criterion of the clinkering that might be expected. It was also desirable that the criterion result from a reasonably rapid method, so that the clinkering characteristics of the coal would be known before shipment. Complaints on the severe clinkering of the ash came from only a fraction of the output of the mine but the occurrence of the clinkering seemed quite unpredictable. Attempts to relate the chemical composition of the ash and the fusion temperatures to the clinkering were unsuccessful. Coal from the area of the mine in which the fusion temperature of the ash was the lowest gave the least trouble from clinker-ing. Chemical analysis of the ash from that section giving the most trouble showed high contents of iron and low contents of silica, but frequently these were not greatly different from those of coals that gave little trouble from clinker. Aside from the clinkering difficulty, the coal was quite satisfactory. The ash content was normal and high rates of burning could be obtained, but again and again such severe clinkering would occur that the furnace would be shut down because of the accumulation of clinker. Examination of the clinker from the customers' plants showed that the clinkers that adhered to the grates and fouled the fuel beds were hard, flat, dense, and usually dark in color. Coal that was satisfactory gave clinkers that were softer, bulky rather than flat, of low density, and usually lighter in color.

Jan 1, 1944

By Raymond S. Weimer

Of the several characteristics of a coal that influence its suitability for use in a given piece of burning equipment, the clinkering and slagging characteristics of the ash of the coal are highly important. They determine the maximum rate at which the coal may be burned on a stoker or in pulverized form without difficulty from damage to metal parts, from erosion of refractory walls, or from stoppage of gas passages by accumulation on the tubes. They also determine the minimum rate at which a slag-tap furnace may be operated without difficulty in removal of the ash in fluid form. Need for a Better Criterion In common with other producers and users of coal, the Northern Illinois Coal Corporation has long used the available methods for the measurement of the clinkering characteristics of coal ash, chemical composition and fusion temperature of the ash, as criteria for the selection of coal that would suit the particular requirements of its customers. These two available criteria have greatly helped in the problem of selection but it is unnecessary to dwell upon the fact that they are not completely adequate for the purpose. The composition of the ash and its clinkering tendency vary widely over the company's mining area. In a certain period, some years ago, an unusual amount of severe clinkering of the ash of coal shipped made extremely acute the need for a better criterion of the clinkering that might be expected. It was also desirable that the criterion result from a reasonably rapid method, so that the clinkering characteristics of the coal would be known before shipment. Complaints on the severe clinkering of the ash came from only a fraction of the output of the mine but the occurrence of the clinkering seemed quite unpredictable. Attempts to relate the chemical composition of the ash and the fusion temperatures to the clinkering were unsuccessful. Coal from the area of the mine in which the fusion temperature of the ash was the lowest gave the least trouble from clinker-ing. Chemical analysis of the ash from that section giving the most trouble showed high contents of iron and low contents of silica, but frequently these were not greatly different from those of coals that gave little trouble from clinker. Aside from the clinkering difficulty, the coal was quite satisfactory. The ash content was normal and high rates of burning could be obtained, but again and again such severe clinkering would occur that the furnace would be shut down because of the accumulation of clinker. Examination of the clinker from the customers' plants showed that the clinkers that adhered to the grates and fouled the fuel beds were hard, flat, dense, and usually dark in color. Coal that was satisfactory gave clinkers that were softer, bulky rather than flat, of low density, and usually lighter in color.

Jan 1, 1944

By George H. Found

DURING recent years considerable interest has been focused on the energy-absorption characteristics of metal when it is cyclically stressed in vibration. The most familiar manifestation of this phenomenon, which is called the "damping capacity" or "internal friction" of a material, is involved in the dissipation of mechanical energy of vibration, which otherwise would build up to stress levels where the problems of noise and fatigue are involved. In addition to its engineering importance in structures, the damping behavior of metals, particularly at low stress amplitudes, has also been used as a unique metallurgical research tool with which to provide sensitive means for indicating certain structural changes within metals. Important contributions toward understanding the energy-dissipating mechanisms that are responsible for internal friction in metals have been made in the last few years. The information is not yet sufficiently extensive, however, to provide a useful metallurgical concept describing exactly how the structure affects the internal friction, or to encourage more general use of this technique among metallurgists. Three fundamental mechanisms have been proposed, as a result of recent experimental investigations, to account for the internal friction in nonferrous metals in low-stress amplitude tests. These include damping due to internal thermal currents that are created and flow in metal because of differential vibratory stress effects,1 damping due to localized inelastic stress relaxation at inhomogeneities within the metal,2,3 and damping related to plastic flow of a localized type for which an explanation has been sought in terms of the dislocation theory.4 How each of these mechanisms functions as a result of structural changes in the metal is, in general, not well understood because of insufficient experimental data for which the controlling variables have been segregated and because of uncertainties in regard to the nature of the structural changes themselves. In several investigations the effects of cold-working on the internal friction of polycrystalline brass and aluminum have been described. As reported by Köster and Rosenthal,5 and by Förster and Breitfield,6 there is an initial large increase in the damping when the metal is worked. The initial high value is not stable, but declines rapidly, at first, in a hyperbolic manner. About 100 hr, after straining, a stable value is reached of magnitude proportional to the amount of strain.7 In Fig. I is shown the relationship found by Zener and his collaborators between the internal friction due to cold-working of alpha brass and the amount of cold-working.8 Several investigators have made internal-friction measurements on worked poly-

Jan 1, 1945

By A. U. Seybolt

Since the time this topic was originally treated in 1954, more recent French3,1 work has been published making it advisable to repeat the earlier oxygen solubility experiments, but using iron of a higher purity. Upon repeating oxygen saturation experiments with zone-refined iron, it was found that the oxygen solid solubility was at least an order of magnitude less than previously observed. SINCE the publication of an earlier paper1 (1954) on this subject by the present author, several contributions on this topic have appeared. Meijering2 in 1955 attempted to reconcile recent conflicting solubility data, without reaching any definite conclusion. sifferlen3 (1955) found that iron of high purity appeared to absorb a quantity of oxygen (0.005 to 0.025 pct) approximately proportional to the structural imperfections present, such as polygonization and grain boundary area. However, he also indicated that purity itself was a significant factor. He concluded that very pure iron nearly free of lattice imperfections would have essentially zero oxygen solubility. His second paper4 (1957) supported this contention since a zone-melted iron containing initially 0.0007 pct O analyzed only 0.0006 pct 0 after prolonged soaking at 850°C with an FeO layer on the surface. Because of the discrepancy between the results of Ref. 1 and those of Sifferlen, it seemed desirable to attempt to resolve this disagreement. EXPERIMENTAL PROCEDURE AND MATERIALS The experimental method used by sifferlen3,1 was essentially the same as that of Ref. 1. In this technique thin iron strip with a surface layer of FeO is soaked for prolonged periods at an elevated temperature in order to saturate the iron with oxygen. After two days at temperatures near 800° to 900° C, one would expect that the iron would be in equilibrium with the surface FeO. In the work reported in Ref. 1 there was evidence that two days holding at 8000to 900°C was more than sufficiently long for saturation. Sifferlen used 48 hr at 850°C. Because of the evidence presented by Sifferlen that the apparent oxygen solubility is a function of iron purity, three grades of iron were used as indicated in Table 1. The Bureau of Standards wire was used only for resistivity tests, while the other two irons were used for saturation-analysis tests of the type described above.

Jan 1, 1960

By William L. Fink, Dana W. Smith

Approximately two years ago the authors obtained data that indicated that initial precipitation could not be detected by change of lattice parameter in the aluminum-rich aluminum-magnesium alloys. Some of these data were first published in a brief note in Mining and Metallurgy'. Cast specimens were used at that time and they showed initial precipitation relatively sooner than sheet material of the same composition. For this reason a more thorough investigation has been carried out using a homogenized aluminum-magnesium sheet corltairling approximately 10 per cent magnesium. Materials.—The aluminum used in the preparation of the aluminum-magnesium alloy was of high purity, containing less than 0.01 per cent each of iron, silicon and copper. The magnesium was high-purity sublimed magnesium. Preparation of Alloy.—Approximately 4 kg. of the aluminunl was melted in a plumbago crucible in an electric furnace and the magnesium was added. The melt was thoroughly stirred with a graphite rod and fluxed with chlorine gas before casting. The alloy was cast in the form of a sheet ingot in a cold iron tilting mold (approximately 200 by 165 by 40 mm.) and into small chill-cast slabs for chemical analysis (75 by 40 by 5 mm.). The chemical analyses were made upon drillings from the analysis slabs. The analytical methods were those described in "Chemical Analysis of Aluminum," published by the Aluminum Company of America. The composition of the alloy was found to be: magnesium 10.30, silicon 0.013, iron 0.008 and copper 0.005 per cent. In order to insure homogeneity the alloy was given two intermediate anneals at 430' C. for a total time of 36 hr. The ingot was hot-rolled

Jan 1, 1937

By V. G. Mooradian, John T. Norton

THE diffusion of metal atoms into the crystal lattice of another metal and the assumption of regular positions to form a homogeneous alloy are some of the most fundamental phenomena of structural. metallurgy. The mechanism of this process has been the subject of a great deal of study from many viewpoints, but the picture is still far from complete. It is generally believed that if one metal is to diffuse into another, the first must have some solubility in the second1. This means that the solvent must be able to accommodate the stranger atoms, either on points of its own lattice or in the interstices between, without losing its own crystallographic identity. It is also a general observation that cold-working is a distinct aid in the diffusion process, causing it to take place with greater rapidity at the same temperature or with the same speed at a lower temperature. There is considerable doubt, however, as to the real significance of the deformation in its effect on the diffusion mechanism. Several factors associated with the cold-working. may be responsible for the increased diffusion rate. The plastic deformation causes a distortion of the solvent lattice, which may be an aid in the assimulation of atoms of another kind. There are many references2 in the literature that suggest that some distortion or "loosening" of the lattice is necessary for atomic migration and that diffusion cannot take place in the undis-

Jan 1, 1935

By R. A. Flinn, R. D. Pehlke, D. R. Glass, P. O. Hays

Knowledge of the depth of penetralion of an oxygen jet into the bath of the oxygen converter and of the correlation of penetration with driuing pressuve, lance heighl, and nozzle throat area is vital to the understanding of converter operation. If the penetration is too shallow, then severe and hazardous slopping takes place. On the other hand, if the jel penetrates entirely Lhvough lhe bath for an apprcciublc period of time, bottom damage occurs. In addilion to measurement of the penetralion of the jel, knou~ledge of the circulatory movement in the bath is also of interest in order to evaluale various theories oj-concerter operating behavior which have been published. In this investigation, experimental converters were buill of IOU- , 300-, and 4000-lb capacity. Four independent methods were used to determine penelralion: the onset of bottom marking, a nitrogen bubbler probe, observation througlt an optical syslew built into the oxygen lance, and direcl viewing of the jet issuing from the bottom of the vessel. Good correlation zuas obtained, and empirical relalions for pvedicling perletration were found. These relations were conjzrmed by bottom marking tests in 55- and 110-ton vessels. Within the operaling conditions employed in these tests, the depth to which a single oxygen jet penetrated zuas found lo vary according to the relatiorl ThE technical literature is replete with data concerning the successful use of the basic oxygen furnace or converter in steelmaking. Experimental data are lacking, however, on the vital factors of the depth of penetration of the jet into the bath and the induced circulation. Commercial operating conditions usually have been the result of cut and try experiments in lance manipulation until satisfactory results were obtained. There have been, however, two hotly argued opposing theories concerning desirable depth of penetration and these are exemplified by the Schwarz and Miles patents1,2 on one hand and the Suess patent3 on the other. The Schwarz patent teaches that the jet, issuing from the nozzle at supersonic speed, penetrates deeply "so that the reactions between the iron and the oxygen and between the oxygen and the rest of the smelting components take place in the center of the bath". Specific operating suggestions are given by Miles.2 By contrast, the Suess patent calls for surface Circulalion was investigated by lour methods: by direct observation in 200-lb open baths, by the use of graphite rudders in the 300- and 4000-lb converlers, by direct observalion through an oplical system in the lance, and by various models al room temperature. All were in excellent agreement and indicated that the motion of the bath ulas up at the center, radially outluavd at the surface, and down at the sides. Experi-ments in small and in commercial vessels indicate that it is essential to operate with a jet penetration of approximately 50 pct of the bath depth. Surface blowing results in low oxygen eficienty and in hazardous conditions which may render the process inopeuable. RejYactory dartzage al the bottom of the vessel is only encountered when the jet penetrates to the bottom, and this can be avoided by properly applying the penetration formula. The application of this en/pirical formula in commercial peraations is best when limited to combinations of lance size, pressure, and height which are typically encounteved in the use of a single-hole lance. blowing so that "...the oxygen jet does not penetrate deeply into the molten metal bath and is confined to an impingement area at the central portion of the bath surface". These references are given merely to illustrate the basic differences between the two schools of thought and to point out the need for measurement of penetration for the sake of the operator. For example, it is shown later that inefficient and even dangerous conditions can arise if improper blowing conditions are used. Differences are also evident between the two schools of thought as to the mixing, circulation, and agitation which is to be accomplished by the jet. The Schwarz patent states that "surface contact is not sufficient in most cases to bring about quick reaction, the same as the blowing of the gas over the bath surface or the mere blowing of the gas onto the bath surface". The patent goes on to call for active mixing. In contrast the claims of the Suess patent call for "discharging a stream of oxygen ... to an extent to avoid material agitation of the bath by the oxygen stream". In this patent the circulation is said to be downward in the center and up at the sides of the vessel. A number of investigators4-12 have explored penetration and circulation in transparent models. In general, it is agreed in these tests that the circulation is upward at the center (along the sides of the jet cavity),

Jan 1, 1968

By Heihachi Kamura

The reduction of iron oxide, such as Fe203, to iron in the blast furnace is performed principally by carbon monoxide, but partly by solid carbon by the two following reactions: Fe2O3 + 3CO = 2Fe 4- 3CO2 2Fe2O3 + 3C = 4Fe + 3CO2 It is known that reduction by carbon monoxide takes place at a much lower temperature than reduction by carbon and that the reducing action of earbon monoxide progresses to the inside of the ore in lump form by gaseous diffusion. In the reduction by carbon, however, the reducing action takes place only at the contact surface of the ore and carbon, so that the more complete the reduction by carbon monoxide, the more efficient is the operation. However, the reduction does not progress as shown in the foregoing equation, because carbon dioxide acts oxidizingly on the metallic iron to such a degree that when the gaseous composition reaches a certain proportion of carbon dioxide to carbon monoxide, the reduction practically stops, even though the gases are moving slowly through the heated ore. The proportions of carbon monoxide and carbon dioxide in the gas depend on the kind of iron oxide and the temperature of reduction, also on the duration of time in the reaction. The longer the time of the reaction, the higher the proportion of carbon dioxide obtained in the gas, but finally it will attain to a condition of equilibrium. Chemical Equilibrium of Iron, Oxygen, and Carbon Investigations concerning the equilibrium between iron, oxygen, and carbon have been carried out by E. Baur and A. Glaessner,1 who deter-

Jan 1, 1925

By Laurence C. Hicks

Consideration of the past work on the subject of the diffusion of chromium into iron suggested that additional information might be given by the use of X-ray spectroscopy in following the concentration changes through the diffusion zone. Grube and Fleischbeinl packed rods of electrolytic iron in a mixture of alumina and chromium. These specimens were heated in an atmosphere of purified hydrogen for varying lengths of time. After treatment the specimens were examined metallographically and showed the usual structure, consisting of a border of radially oriented columnar grains ending in a sharp boundary line. Reference is made to the fact that etching with certain reagents will attack only the material inside the border of columnar growth and also to the fact that polishing seems to develop a ridge at the position of the boundary between the etched and unetched areas. By chemical analysis of thin layers turned off on a precision lathe, the authors were able to obtain depth-concentration curves. These curves, reproduced in Fig. 1, show that in most cases a pronounced change of slope occurs, corresponding to the position of the boundary of the columnar grains. In a laler paper Grube extends his work to other systems which show the same characteristics.~ He concludes that the reason for the break in the curve is that a hindrance of diffusion occurs at the place where the regularly oriented grains of the diffusion zone meet the random grains of the interior portion, on the assumption that the diffusion velocity in one direction in a grain may be greater than in another direction, and that the grains in the diffusion zone orient themselves so as to give the maximum diffusion rate. Kel1ey" points out that Grube has failed to note that the boundary line does not consistently cross all grains and

Jan 1, 1934

By Ralph Hultgren, David W. Mitchell

MAGNESIUM alloys usually are superheated before casting in order to ensure fineness of grain. Superheat temperatures in common use range from 1600° to 1700°F while the casting temperature, which depends upon the mold shape, is usually 200° to 300°F lower. The process of superheating requires considerable time and seriously shortens the life of the iron pots used. Recently it has been reported' that if acetylene, carbon dioxide or natural gas is bubbled through molten electrolytic A.S.T.M. No. 4 alloy at 1400°F. for 5 min., grain refinement equivalent to that of superheating will take place. Addition of certain solids such as graphite or aluminum carbide accomplishes the same results.2 As will be shown in this paper, it is possible to achieve grain refinement in magnesium casting alloys at low temperatures by mechanical stirring of the molten metal for a short time. This process was developed in the course of research work, supervised by the War Metallurgy Committee under the "Restricted" Project NRC-550, for the Office of Production Research and Development of the War Production Board. This paper, based on that work, has been released for publication by the O.P.R.D. MATERIALS AND METHODS The alloys studied were the most common American sand-casting alloys designated as No. 4 and No. 17 by the American Society for Testing Materials. The magnesium used in these alloys was of both carbothermic3 and electrolytic4 origin. Chemical analyses supplied by the producers are shown in Table I. Each heat consisted of approximately 5 lb. of alloy melted in a Tercod crucible. It was refined by fluxing with Permanente No. 7* refining flux at 1300° to 1350°F. After cooling to 1200' to 1250°F., portions of approximately one pound each were ladled into iron crucibles contained in an electric furnace at about 1250°F. The molten metal was covered with Permanente No. 21† covering flux and then heated to the temperature to be investigated. Normally each of the four portions was given a different treatment. In a typical case one portion was stirred vigorously for 5 min., acetylene gas was passed through a second portion for 5 min., a third portion was superheated to 1600°F for 15 min., then cooled to casting temperature, and the fourth was held for 5 min. at the temperature of stirring or gassing without other treatment. Each portion was then cast into one-inch diameter cylinders in three "nonturbulent" molds of identical shape. One mold was made of cast iron and the other two of baked sand. The cast-iron mold and one of the baked sand molds were heated to 360°F., the other baked sand mold was at room temperature. The freezing times in these molds were

Jan 1, 1945

By Roscoe C. Clark

In October 1945. R. F. Farris. in an AIME paper entitled Method For Drtermining Minimum Waiting OIL Cenzent Time, presented a method for caiculating the minimum WOC* time required in oil well cementing operations. Briefly. this method consisted of shutting in a well. after the cement had been placed and noting the time required fur the wellhead pressure to reach a. maximum. This time was then multiplied by a factor of 1.5 to determine when the cement had reached sufficient strength to support the weight of the casing. As a result of this work, a number of areas have reduced their WOC time ~Wuirements with the subsequent saving of considerable rig time. The tests conducted by Farris were, for the most part, conducted under cementing temperatures in excess of 70°F. This was done because in the overwhelming majority of cases. cementing temperatures are in excess of 70°F (only in tile northern part of the country. primarily in the Rocky Mountain ares. in cementing surface casing are temperatures below 70° F. encountered, and such temperatures occur only during the winter months). The Stano-lind Research Laboratory since that time has performed a number of tests both in the laboratory and in the field to evaluate this WOC factor when cemeriting temperatures are lower than 70°F. The results of these tests indicated the need for greater WOC time in areas affeaed by abnormally low cementing temperatures. These tests indi.cated that a woc factor of 2 (Time from start to mix cement to maximum wellhead pressure x 2 = Time to drill plug) will allow sufficient time for the cement to develop adequate strength. A field test under abnormally low cementing temperatures (surface temyerature 35°F., mud discharge temperature <70°F. and cementing depth 500 ft.) in the Rangely Field, "* using the WOC factor of 2, indicated the time to drill the plug as 45 hours. Well conditions preventing getting back into the well until a 48-hour WOC time had elapsed. At this time, the plug drilled firm to hard indicating that the cement had reached its final set. It is contemplated that during next winter additional field tests will be performed to further check the results of the laboratory and field tests conducted to date,

Jan 1, 1949

By Roscoe C. Clark

In October 1945. R. F. Farris. in an AIME paper entitled Method For Drtermining Minimum Waiting OIL Cenzent Time, presented a method for caiculating the minimum WOC* time required in oil well cementing operations. Briefly. this method consisted of shutting in a well. after the cement had been placed and noting the time required fur the wellhead pressure to reach a. maximum. This time was then multiplied by a factor of 1.5 to determine when the cement had reached sufficient strength to support the weight of the casing. As a result of this work, a number of areas have reduced their WOC time ~Wuirements with the subsequent saving of considerable rig time. The tests conducted by Farris were, for the most part, conducted under cementing temperatures in excess of 70°F. This was done because in the overwhelming majority of cases. cementing temperatures are in excess of 70°F (only in tile northern part of the country. primarily in the Rocky Mountain ares. in cementing surface casing are temperatures below 70° F. encountered, and such temperatures occur only during the winter months). The Stano-lind Research Laboratory since that time has performed a number of tests both in the laboratory and in the field to evaluate this WOC factor when cemeriting temperatures are lower than 70°F. The results of these tests indicated the need for greater WOC time in areas affeaed by abnormally low cementing temperatures. These tests indi.cated that a woc factor of 2 (Time from start to mix cement to maximum wellhead pressure x 2 = Time to drill plug) will allow sufficient time for the cement to develop adequate strength. A field test under abnormally low cementing temperatures (surface temyerature 35°F., mud discharge temperature <70°F. and cementing depth 500 ft.) in the Rangely Field, "* using the WOC factor of 2, indicated the time to drill the plug as 45 hours. Well conditions preventing getting back into the well until a 48-hour WOC time had elapsed. At this time, the plug drilled firm to hard indicating that the cement had reached its final set. It is contemplated that during next winter additional field tests will be performed to further check the results of the laboratory and field tests conducted to date,

Jan 1, 1949

By Shueling Woo, Charles S. Barrett, Robert F. Mehl

When one solid phase is generated from another, fixed and rational orientation relationships are observed to subsist between the parent and the new crystal. The principle has been proposed1 that the relationships obtaining between the same two phases are identical whatever the type of phase change involved, or whichever of the phases may act as parent. Many types of phase changes have been studied: allotropic transformations in pure metals, precipitation from solid solutions, eutectoid decompositions, peritectic reactions, the formation of oxide layers, and others2 Phase layers generated by diffusion of one metal into another constitute an additional type of reaction. This report provides new data on the orientation relationships occurring between phase layers formed by diffusion, in the Cu-Zn system,§ and furnishes further evidence in support of the principle. Materials and Methods The Cu-Zn system is especially suitable for these studies since the high vapor pres- sure of Zn provides an opportunity readily to create one phase poorer in Zn upon a parent phase richer in Zn by removing Zn by vaporization, or to reverse this process by adding Zn from Zn vapor; e.g., the beta phase can be found as a layer upon gamma by dezincing, or gamma can be found on beta by addition of Zn from Zn vapor. Since orientation relationships are to be sought, requiring crystals large enough for orientation determinations, it is convenient to prepare single crystals or large grains of the parent phase. The samples were prepared from oxygen-free high-conductivity copper and Horse Head zinc by melting under a borax flux in a graphite crucible. Large crystals of beta brass were grown by the strain-anneal method, in plates sectioned from the cast ingots, by the following procedure. Rockwell-hardness indents were made at I cm. intervals and with various loads, then the plates were annealed for 4 days at 700°C. in Nichrome boxes packed with beta-brass chips and graphite. Surface layers were removed by grinding and etching to a depth of about 1.0 mm., and individual grains were cut out. Crystals of alpha and gamma brass were prepared by freezing, by lowering a graphite crucible at speeds less than one inch per hour through a furnace held at a constant temperature above the melting point. Single crystals were cut out with a jeweler&apos;s saw, ground, polished and etched. Care was taken to remove cold-worked layers from the finished crystals

Jan 1, 1944

By Charles S. Barrett, Robert F. Mehl, Shueling Woo

When one solid phase is generated from another, fixed and rational orientation relationships are observed to subsist between the parent and the new crystal. The principle has been proposed1 that the relationships obtaining between the same two phases are identical whatever the type of phase change involved, or whichever of the phases may act as parent. Many types of phase changes have been studied: allotropic transformations in pure metals, precipitation from solid solutions, eutectoid decompositions, peritectic reactions, the formation of oxide layers, and others2 Phase layers generated by diffusion of one metal into another constitute an additional type of reaction. This report provides new data on the orientation relationships occurring between phase layers formed by diffusion, in the Cu-Zn system,§ and furnishes further evidence in support of the principle. Materials and Methods The Cu-Zn system is especially suitable for these studies since the high vapor pres- sure of Zn provides an opportunity readily to create one phase poorer in Zn upon a parent phase richer in Zn by removing Zn by vaporization, or to reverse this process by adding Zn from Zn vapor; e.g., the beta phase can be found as a layer upon gamma by dezincing, or gamma can be found on beta by addition of Zn from Zn vapor. Since orientation relationships are to be sought, requiring crystals large enough for orientation determinations, it is convenient to prepare single crystals or large grains of the parent phase. The samples were prepared from oxygen-free high-conductivity copper and Horse Head zinc by melting under a borax flux in a graphite crucible. Large crystals of beta brass were grown by the strain-anneal method, in plates sectioned from the cast ingots, by the following procedure. Rockwell-hardness indents were made at I cm. intervals and with various loads, then the plates were annealed for 4 days at 700°C. in Nichrome boxes packed with beta-brass chips and graphite. Surface layers were removed by grinding and etching to a depth of about 1.0 mm., and individual grains were cut out. Crystals of alpha and gamma brass were prepared by freezing, by lowering a graphite crucible at speeds less than one inch per hour through a furnace held at a constant temperature above the melting point. Single crystals were cut out with a jeweler&apos;s saw, ground, polished and etched. Care was taken to remove cold-worked layers from the finished crystals

Jan 1, 1944

By Carl F. Dietz, Dyke V. Keedy

The problem of drying ores is one that most mill-engvineers are sooner or later called upon to meet, and it may be timely to point out some of the difficulties resulting from such operations from purely a metallurgical and economic standpoint. We mean, in the following pages, to discuss primarily the effect of such operations on the ore. itself, without particular reference to the mechanical or cost features of the subject. That an appreciable tonnage of the ore fed to the usual form of drier, either rotary or stack, is lost, is fairly well appreciated, but we believe that only a few mill-managers know just what their drier-losses amouilt to, and we have found that in most cases they console themselves with the fact that the drier-smoke is not very much discolored, and it is generally believed that the draft is not sufficient to carry away more than a negligible percentage of the values.

Jan 1, 1913