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By R. M. Hudson

The removal of nitrogen from a nitrogenized low-carbon sheet steel that contained 0.011 wt pct N was determined during heat treatment in Hz-N, mixtures. TIze process followed a first-order rate law; that is, plots of the logarithm of nitrogen content in steel were linear with the time of treatment at a given temperature. The rate of removal increased with an increase in temperature from 900" to 1300°F. By 1400°F the rate in dry hydrogen had decreased to a value intermediate between the rates at 1200" and at 1300°F; in wet (2.47 vol pct water vapor) hydrogen the rate at 1400°F was less than the rate at 1300°F and nearly the same as the rate at 1200OF. The rate at a given temperature increased as the 3/2 power of hydrogen concentration in the atmosphere. While wet atmosplzeres were generally more effective than the corresponding dry atmosplzeres, the effect of water vapor was much less pronounced than the influence of hydrogen content. NITROGEN is the principal agent in the strain aging of ferrite, the effect of carbon being secondary.' To eliminate the return of the yield point after straining and aging, it is claimed2 that the amount of nitrogen in solution in steel must be reduced to 0.0002 wt pct. Strong nitride-forming elements (titanium, vanadium, zirconium, and aluminum) can act to eliminate strain aging by combining with nitrogen. It is extremely difficult to decrease the nitrogen content in commercial steels to the low level required by conventional coil annealing because of the poor contact between the strip surface and the reactive atmosphere. However, a variety of gas-metal reactions can be effected by use of the open-coil annealing method,3 in which the metal surface is fully exposed to the atmosphere. With this possibility in mind, the Applied Research Laboratory has studied the influence of time, temperature, and atmosphere composition on the removal of nitrogen from low-carbon sheet steel. MATERIALS AND EXPERIMENTAL WORK Samples from a commercial nitrogenized low-carbon steel (0.010 in. thick) in the cold-reduced condition were used. The chemical composition of this steel is given in Table I. The gas mixtures used are listed in Table 11. The moisture content in the "wet" annealing atmospheres was controlled at a +70°F dew point (2.47 vol pct water vapor) by passing the gas mixture through a glass tube packed with a solid mixture of 10 pct anhydrous oxalic acid and 90 pct oxalic acid dihydrate held at 127°F; this technique has been described previously.4 For "dry" atmospheres, the gas mixtures were passed through a cold trap immersed in liquid nitrogen. A hinged-top Hevi-Duty electric furnace was used with a Vycor-glass furnace tube. When the furnace was at the desired temperature, the gas mixture was passed through the furnace at a flow rate between 1.1 and 1.2 cfh; coupons (size 3 by 3/4 in.) of the steel were pulled into the center of the Vycor-glass

Jan 1, 1964

By Charles Bohdanowicz

The accompanying tables' show that in 1936 production of crude oil in Poland decreased very slightly (Tables 1 and 5), by about 1 per cent, and that gas production increased by about 11 per cent. As in preceding years, drilling (Tables 1, 2 and 3) was devoted principally to extension of oil fields in the Jaslo district (fields 1, 5 and 7) and, in a lesser degree, of those in the Stanislaw6w district (field 27). Production of crude oil is being sustained in a large measure by the deepening of old wells; besides a total number of 183 new wells completed (Table 3) about 152 wells were deepened, and in a general way the results of deepening were better than those of new wells drilled. Reserves of "proved land" have not increased as far as crude oil is concerned, but a notable extension of gas fieldsZ was attained in Daszawa (field 25) and in the Roztoki area (field 5). In the sub-carpathian zone gas fields have been proved in the vicinity of Kalusz, Kos6wJ and in the northwestern sector of that zone, between Tarnow and Lezajsk. The gas horizons of Daszawa occur in the Upper Tortonian, those of Kos6w in the Lower Tortonian (Middle Miocene). Exploratory drilling has been performed near Kalusz, and has been commenced near Kos6w and in the Tarn6w area. The Kos6w gas approaches the "wet" type. A possible gas reserve with a volume of 4,000,000,000 cu. m. (141,000,-000,000 cu. ft.) has been calculated, for an area of about 5 sq. km. of the Daszawa field, on the basis of production obtained and of decreases in pressure and their distribution. The fields of Roztoki and Strachocina (No. 12) have not yet supplied sufficient data for a calculation of reserves, which might possibly be estimated at 2,000,000,000 cu, m. (70,000,-000,000 cu. ft.).

Jan 1, 1937

By R. B. Gordon, D. A. Koss

Ultrasonic-atlenuation changes due to the formation of free dislocations have been observed during tensile tests of magnesium and LiF single crystals and samples of polycrystalline Results on the LiF and samples are similar: A preyield attenzration increase is observed which, however, be-corlzes smaller as the magnitude of the drop in load al yielding increases. This indicates that the yield point observed in these materials is due to dislovation rather than dislocation unpinning and that the initial density ' free dislocations must be low if the yield point is to be sharp,. Tests on the magnesium ere conducted at both 27" and 200C. Magnesium has the unusual property that the yield drop is larger at the higher test temperature and is accomplished by a decrease in attenuation. The latter is due principally to the temprovary pinning of detained dislocations by highly solute atoms. After strain aging., a stress as low as 0.3 bur suffices to unpin dislocations; microstrain measuements of sufficient sensitivity should. reveal plastic flow at stress levels this low IN another paper,' we describe the technique of simultaneously observing ultrasonic-attenuation changes and plastic microstrain during deformation of spher-oidized carbon steels. Changes of ultrasonic attenuation indicate damping effects caused by the oscillation of long, freely moving dislocation segments. Simultaneous microstrain measurements are used to indicate total dislocation motion. The dislocation-damping observations are most useful in the study of the early stages of deformation where the dislocation density is low and the plastic strain is small and relatively difficult to measure. Particularly interesting results are found in materials which display sharp yield points. Observations of these phenomena are reported here for three materials: single-crystal LiF and magnesium, and poly crystalline molybdenum. EXPERIMENTS Dislocation-damping effects were observed by measuring changes in acoustic attenuation with the ultrasonic-pulse method. The end faces of each of the specimens were ground flat and parallel and a quartz 10 Mc per sec, x-cut transducer was attached to one face. The bonding agents used were: a) "Nonaq" stopcock grease with magnesium, b) beeswax with LiF, and c) salol with molybdenum. With the LiF, the best acoustic signals were obtained at 45 and 50 Mc per sec; all other measurements reported are at 10 MC per sec. The Sperry Ultrasonic Attenuation Comparator2 was used to measure attenuation changes. In the

Jan 1, 1967

By Oscar Marzke

STUDIES on the precipitation of a face-centered from a body-centered structure-a common occurrence in alloy systems-are essential to the development of a theory for the formation of segregate structures. The separation of the alpha phase from the beta of the copper-zinc system is an example of this type of precipitation. EARLIER STUDIES ON THE SUBJECT R. F. Mehl and 0. T. Marzke1 in 1931 presented a paper giving the results of some investigations carried out by them on the segregate structures produced when the alpha and gamma phases of the copper-zinc system and the alpha phase of the copper-aluminum system precipi-tate from the beta phases of these systems. They showed that the alpha phase precipitates as needles close to the [111] directions of the beta phase. In the discussion of that paper some doubt was expressed about the nature of the segregate. More investigations were undertaken to determine the character of the precipitate in the copper-zinc system and also the orientation relationship between the matrix and precipitate. The present paper gives the results of these investigations. Since the publication of the earlier paper, several other papers on this subject have been published in this country and abroad. Haneman and Schroder2 reported that the alpha phase precipitates as needles along the [111] directions of the beta phase and that these needles align themselves to form plates on the {111} planes of the matrix. Mathewson and Smith3 pointed out that the {111} plane does not contain the [111] direction and that it would be quite impossible, therefore, for needles in the [111] direction to form plates on the {111} plane. They suggested

Jan 1, 1933

By John W. Cahn

The spinodal has long been regarded as a limit beyond which a homogeneous phase could no longer be metastable. But only recently has it become apparent that a phase beyond the spinodal would decompose by simple diffusional clustering mechanism quite different from the nucleation and growth mechanisms encountered for metastable phases. The theory of spinodal decomposition, which is based on the diffusion equation modified by thermodynamic requirements , is phenomenological, and each parameter can be measured by independent thermodynamic or diffusion experiments. The details of the theory have been carefully verified in a number of simple systems. It appears that the spinodal mechanism is commonly encountered in clustering reactions in solids and glasses. HISTORICAL INTRODUCTION The understanding of the earliest stages of precipitation in alloys has been the subject of three prior Institute of Metals Lectures. In 1932 Paul ~erica' reviewed the puzzling evidence that hardening of duralumin is completed before precipitation of CuAlz takes place and suggested that hardening occurs when the copper atoms "assemble in random groups on lattice positions of the duralumin, not of the CuAlz lattice". He called these random groups knots. This modification of his dispersion hardening theory seemed to fit all the facts, but Merica worried that the required diffusion "is just the reverse of what we deem normal; although quite spontaneous, it proceeds uphill, if you please". The reality of Merica's knots was quickly confirmed by Guinier's' and preston's3 X-ray work and these knots are today known as G.P. zones in their honor. Theoretical justification for uphill diffusion was also quickly provided by Becker and Dehlinger~ who noted that the diffusion coefficient could be negative in certain regions of phase diagrams. The boundaries of such regions could be described by a 90-year-old thermodynamic concept first described by ~ibbs' in 1877 as a limit of metastability for fluid phases, which by 1890 had received the name spinodal (see Appendix A). Spinodal in fluids is as old as nucleation theory. Both appear for the first time in the same paper by Gibbs who called the spinodal the limit of metastability. For the first 50 years, nucleation theory was forgotten and the spinodal was extensively treated in every good thermodynamics textbook.81Q The idea was simple and logical and it was accepted as part of a rigorous thermodynamic development of metastable phases, and for a while it was extensively investigated theoretically.

Jan 1, 1969

By R. E. Miner, J. K. Jackson, T. L. Wilson

A study has been made of the transformation kintetics and morphology in gas-quenched Fe-5 pct Ni alloys. Massive ferrite or nlurtensite was found to form at temperatures in agreement with earlier results. Surface Preparation appeared to have the greatest effect in determining the type of transformation Product formed. Grain size change, subgrain morphology, and dislocation densities of massive ferrite were essen-tinlly invariant functions of cooling rate. The mar-tens~tic structures were typical of transformation in austenite grains of the order of the sample thickness. BY introducing the idea of a massive transformation in dilute iron-base alloys, Gilbert and Owen in 1962 served to stimulate a closer inspection of phase transformations in ferrous systems.' A wealth of literature has followed concerned with the morphology,2-5 transformation mode,2'3'6-8 and thermodynamics of transformations.2,5,9 interesting controversies have resulted from the experimental observations; closer attention has been paid to the definition of massive transformations and still to be resolved is the Ms temperature of pure iron. The purpose of this note is to report some observations made in a detailed kinetic and metallographic examination of the transformations that occur in gas quenched Fe-5 pct Ni. The results are pertinent to the Ms extrapolations that have been made for pure iron and the observed substructure of massively transformed alloys. PROCEDURE The material used in this investigation was cast as a 5 lb vacuum induction melted, carbon deoxidized heat. The ingot was hot worked to a strip 0.10 in. thick, decarburized, and cold rolled to final thickness. Specimens were punched to sample shape and decarburized in wet hydrogen at 600°C. The chemistry of test specimens is indicated in Table I. Samples 1 by $ in., by thickness were resistance heated and rapidly cooled in an apparatus as illustrated in Fig. 1. Similar helium quenching apparatuses have been described previously;2,6'10 the distinguishing feature of this apparatus is the nozzle geometry. Twin nozzles with three convergent-divergent, sonic ports were mounted perpendicular to the specimen for quenching purposes. The specimen temperature was monitored with an intrinsic 3 mil chromel-alumel thermocouple spot welded to the specimen and con- nected to an oscilloscope. A single switch stopped the current flow through the specimen, opened a gas flow solenoid valve, and initiated an oscilloscope sweep. Cooling rates were read directly from a photograph of the oscilloscope trace and the quenching rates quoted later were made at a point immediately prior to transformation on the trace. All quenching studies were conducted either under a vacuum of 10"-5 torr or a helium atmosphere. The sample geometry was chosen large enough to permit optical and electron microscopy to be performed on samples. The samples were electropolished for both types of examination in a perchloric-acetic solution. Electron microscopy was conducted on a HU 11A microscope operated at 100 kv. Dislocation densities were determined at the same general operating reflection (110) on foils thick enough to produce Kikuchi patterns. RESULTS AND DISCUSSION Transformation Temperature Observations and OD-tical Microscopy. The quenching results of this study are illustrated in Fig. -2(a). Samples which were treated in the as-decarburized condition transformed in a manner similar to that reported previously—a decrease in transformation temperature occurred as the quenching rate increased until a plateau region was reached. Within the scatter of the results obtained here, there was no break in the transformation temperature-quenching rate plot. This suggests no change in transformation mode. Further metallographic examination confirmed this observation. A martensitic transformation was obtained for similarly treated samples except that the surface was first electropolished. The Ms temperature was approximately 85°C below the plateau determined for the unpolished samples and cooling rates as slow as 2000°C per sec were adequate for producing marten-site. The transformation temperatures are in gen- / STRIP SAMPLE / COPPER I SAX/-/}' / CONNECTOR-----A f, SON|C poRTS AC LEADS 3j ]j"I rofe[ \ Mf/yinK/iKj''^ THERMOCOUPLE X-(^—iie"s*c? ' LEADS 1 INCH Fig. 1-—Schematic scction of gas quenching apparatus

Jan 1, 1970

By Edward Adarns Richardson

As developed up to the end of the Great War, an airplane was essentially a mechanism of wood and fabric, joined and held together by metal fittings and fastening. The engine and accessories, wire for wheel spokes and other tension members, and the occasional use of metal for inter-plane struts and the shafts of surface controls required some metal, but essentially it was a wood and fabric structure. Attempts had been made to use metal for other purposes, such as struts in the drag-trussing of wing panels and for short interplane struts, and Junkers had produced an airplane of iron in 1915. By 1917 he was using steel tubes and duralumin sheets, securing noteworthy advantages aerodynamically and from the standpoint of weight and upkeep. He was a pioneer along lines in which progress is still being made. Principles of Airplane Construction The loaded weight of airplanes ranges from 500 lb. for the light plane of which we heard so much a short time ago, to about 40,000 Ib. The great majority of planes range from 2000 to 10,000 Ib. Of this weight from 15 to 30 per cent. is for the dividend-earning load. This percentage is so low that every per cent. saved on the rest of the weight increases the pay load from 3 to 6 per cent,. The economic value of every pound that can be saved in designing or constructing a plane is sufficiently great to warrant spending money on refined methods of structural analysis, materials of superior strength properties for a given weight, methods of manufacture which may make possible the use of refinements in structural design, and the like, to an extent unknown heretofore. The weight of the airplane, without fuel, oil and crew, and pay load, ranges from 50 to 65 per cent. of the total weight loaded for planes suitable for commercial use. It is doubtful if the structural weight will ever be brought down to as low as 40 per cent. for commercial planes. The airplane may be roughly divided into: (1) Power plant, which includes engines, radiators, cooling water, oil and fuel tanks, piping, propellers, engine-starting systems, pumps, super-

By Oliver Smalley

EXCEPT for the work of Guillet, who conducted a systematic investigation on the zinc-replacing value of nickel in brass, and extended his investigation with a view to developing commercial high zinc content nickel brasses, the author does not know of any systematic research on the subject. The most promising commercial alloys and their physical properties obtained by Guillet are given below: Maximum Elonga- Reduction Copper Zinc Nickel Stress, tion, of Area, Brinell Tons Per Per Cent. Per Cent. Sq. In. 55.0 41.0 5.0 24.4 46.5 94 Sand cast. 22.6 27.0 90 Chill cast. 56.7 39.74 3.35 30.0 43.0 51.7 97 Casting annealed 2 hr. at 750° C. 33.9 33.0 50.7 144 Cold-drawn bar. 55.15 42.3 2.24 29.8 33.0 116 Casting annealed 2 hr. at 750° C. 32.3 29.0 151 Cold-drawn bar. These test results scarcely justify the use of such quantities of so expensive a metal, and could have been obtained from ordinary commercial brass. For purposes of comparison, the physical properties of ordinary brasses, ranging from 70 per cent. to 50.1 per cent. Cu in both the cast and normalized1 conditions are included in Table 1. These incidentally furnish a useful standard of the properties of castings and of rolled, extruded and forged brass when correctly annealed. A close study of some of the well-known special brasses containing nickel reveals a series of alloys which bewilder by their complexity, and one can only hazard a guess at the function and commercial value of each of the many elements used.

Jan 10, 1925

By F. H. Wilson, R. M. Brick

WITH the papers of Palmer and Smith1 and of Burghoff and Bohlen,2 published in 1942, understanding of the problem of the development of ears on deep-drawn brass cups was brought to the point where, from a practical standpoint, producers of brass sheet could keep earing under control. However, these very practical results raised questions concerning the reasons for the observed behavior. Since plastic deformation is fundamentally a function of crystallographic slip, these reasons must be considered in the light of the textures to be found in the annealed sheet. Various attempts have been made to interpret the mechanism of ear formation by correlation with the preferred orientation and the anisotropy of the sheet. However, none of these has satisfactorily explained why ears are usually found in the rolling and transverse directions for copper but at 45° to these directions for brass. This paper offers additional data on these two related subjects and has been divided into two sections. The first section provides a survey of the recrystallization textures of brass as affected by annealing temperatures and prior reductions, and an account of the earing behavior which accompanies these textures. The second section reports new data on the anisotropy that accompanies a characteristic texture for brass and endeavors with partial success to establish the factors that account for the difference in earing behavior between copper and brass. EARING BEHAVIOR OF BRASS Review of Textures The recrystallization texture of severely rolled brass was first reported by Bass and Glocker.3 The preferred orientation to which this texture, obtained from metal annealed at 500°C., was most akin was (113)[112]. This texture has been confirmed by Bauer, von Göler and Sachs;4 Brick;* Brick, Martin and Angier;6 and Cook and Richards7 who, in general, used annealing temperatures under 500°C. Bass and Glocker3 also reported the recrystallization texture at 850°C. to be the same as at 500°C. They analyzed their textures by means of single photograms obtained with white radiation. The photograms for both temperatures are reproduced in their paper, and there is a strong similarity between the two. However, for the latter temperature, the number of spots registered on the film was remarkably large for the grain size to be expected, and the authors made no mention of using a technique that would integrate a large enough area of the specimen to produce so many spots. The only other attempt to determine textures resulting from high temperature

Jan 1, 1945

By W. S. McCain, B. A. Wilcox, A. H. Clauer

The creep and creep-fracture behavior of a Ni-200-2Th0, alloy has been studied over the temperature range 816° to 1038°C and stress range 4000 to 19,000 psi Specimens having their axes either parallel or transverse to the final sheet-rolling direction were tested in air, and the apparent activation energy for creep was found to be 92 kcal per mole, regardless of specinien orientation. The stress dependence 01- the steady-state creep rate, was satisfied by where n depended on orientation; n = 9.7 for rrzaterial transverse to the rolling direction and n = 24.3 for material parallel to the rolling direction. In the latter case, the relation was also valid. The rupture strength of material parallel to the rolling direction was -1.5 times gveater than the transverse rupture strength. Several tests in vacuum revealed that here the creep rate was higher and rupture life lower than for comparable tests in air. THERE is an increased interest today in producing improved dispersion-hardened alloys for high-temperature structural applications. This had led various materials designers to modify existing alloys, such as thoriated nickel. One system that has received considerable attention is based on chromium additions to Ni-ThO2, with the obvious motive of improving the oxidation resistance. Another effect of chromium is that of lowering the stacking-fault energy, y, of nickel. For example, the addition of 30 wt pct Cr decreases y from -225 erg per sq cm for pure nickel1 to -70 erg per sq cm.' This decrease in y could have several effects on the deformation behavior. There is some evidence that cross slip of dislocations around Tho2 particles is a mechanism of tensile3 and creep4 deformation in TD Nickel (Ni + 2 vol pct ThO2) at temperatures below 0.5 the absolute melting point of nickel, T,. A decrease in ? by chromium additions should increase the difficulty of cross slip. Also it has been suggested that the high-temperature (T > 0.5Tm) rate-controlling creep process in "recrystallized" Ni-Tho2 alloys is the climb of edge dislocations over Tho2 particles.5 According to weertman6 a decrease in the stacking-fault energy should decrease the dislocation climb velocity resulting in a decreased steady-state creep rate. Thus, chromium additions to recrystallized Ni-Tho2 alloys would be expected to decrease the creep rate, all other conditions being constant. However, a difficulty arises when the stacking-fault concept is applied to high-temperature creep of dispersion-strengthened metals which are produced on a commercial or semicommercial scale. This occurs because the materials are processed so that they have a high-stored energy of cold work, and the other substructural effects could obscure any influence of stacking-fault energy per se. An example of an alloy with a high stored energy of cold work is TD Nickel bar. This material has a fibrous grain structure (1 I diam by 10 to 15 p long), and the structure is stabilized by the ThO2 particles. Annealing at high temperatures, e.g., 3 hr at 1300°C, causes no recrystallization or grain growth.4 Previous work by the authors4 showed that the high -temperature creep behavior of TD Nickel could not be related to any simple dislocation theory of creep, and this probably was associated with the complex initial structure of the material.

Jan 1, 1968

By T. D. Thomas

CONTENTS PAGE T. D. Thomas-Misfires in Anthracite Coal Mines 3 W. H. Forbes-Misfires in Bituminous Coal Mines 12 A. W. Worthington-Misfires in Non-metallic Mining (Limestone) 18 Misfires in Anthracite Coal Mines BY T. D. THOMAS,* LANSFORD, PA. (New York Meeting, February, 1929) IN THIS paper, major attention is given to misfires in mines where electric multiple shot-firing is the system used. Misfires are sometimes caused by one action or condition and at other times by a combination of two or more. They may be divided into two classes: (1) those caused by workers in the mines, (2) mechanical or manufacturer's causes. The second cause will be discussed first. MISFIRES CAUSED BY FAULTY DETONATORS The important part of an electric blasting cap, to the user where multiple shot-firing is done, ass in the steep-pitch, thick-vein, anthracite mines, is the bridge wire. In single shot-firing this factor is not apparent, but in mines where multiple firing is done any variation in the resistance of the bridge wire, where full or even rated battery capacity is required, will most likely cause a misfire The reason for this is obvious. If the resistance in the bridge wires is not the same, some of the detonators will fire because of their greater comparative resistance. Variance in resistance of bridge wires is caused by a slight difference in the diameter of the bridge wire, also to a difference in the composition of the bridge wires. Again, where the bridge wires have become rusted, there will be a variance in resistance. About the year 1922, one of the large coal companies was greatly alarmed by the number of serious and fatal accidents caused by misfires. The general manager issued an order that these accidents must be greatly reduced, and if possible, entirely prevented.

Jan 1, 1929

By R. E. Pollard

The National Bureau of Standards received, in August 1940, a number of samples of bridge wire taken from the cables of the General U. S. Grant suspension bridge over the Ohio River at Ports- mouth, Ohio. These cables were 7% in. in diameter under the wrapping and each was made up of 1458 ungalvanized wires of No. 8 gage in 3 parallel-wire strands. The choice of ungalvanized wire was based on the previous satisfactory performance of similar wires in other bridges over periods of 20 to 50 yr. of service(1).2 After about 12 yr. of service a number of breaks were discovered in the Portsmouth bridge cables, most of them at the anchor- age shoes, and they were replaced by cables made up of galvanized wire(2).

Jan 1, 1945

By F. R. Hensel

THE present study was rude to determine the laws governing the formation of the primary? crystal structure during solidification. Most of the experiments were carried out on chill castings, but from the results it will be possible to draw certain conclusions as far as sand cast-ings are concerned. It is necessary to discuss first a number of theories, which are generally adopted for explaining the structure of an ingot. Usually, the structure FIG. 1.-VARIOUS ZONES IN A CHILL INGOT. off an ingot consists of the following three zones (Fig. 1): (1) a chill layer of small at. random oriented crystals; (2) a layer of columnar crystals; (3) a zone of equiaxed crystals. The tensile properties of the chill layer and the equiaxed range are usually much better than in the columnar range, particularly the planes that are formed by the columnar crystals growing from two sides at right angles leave low tensile properties. This is one of the reasons why colum-nar crystals in ingot structures are undesirable.

Jan 1, 1937

By W. F. Holbrook, T. L. Joseph

The problem of sulfur control is important in all blast-furnace operations but particularly for certain grades of steel because of the rigorous specifications. During the past decade the tendency has been to produce pig iron and hot metal of lower sulfur content. As most of the sulfur in the iron originates in the fuel, the use of high-sulfur coke demands modifications in practice to meet sulfur specifications. While it is generally known that high temperatures and more basic slags favor desulfurization, operators as a rule produce the most acid slag that will permit proper desulfurization. The viscosity of blastfurnace slag has been thought to be related to desulfurization and has been investigated by Feild and Roysterl, also McCaffery and his associates*, but apparently no systematic effort has been made to determine the relative desulfurizing powers of slags over the range of composition encountered in practice. Development of Testing Method Because slag and metallic iron are immiscible, the desulfurization reaction is heterogeneous, occurring only at the interfaces between slag and metal bodies. In the blast furnace the newly reduced iron, containing FeS, descends through the slag bath probably either as small drops or streams, at the interfaces of which desulfurization occurs. After its descent through the slag the iron collects to form a bath of metal, at the top surface of which desulfurization reaction probably occurs. These two steps have been thought to account for all desulfurization in the blast furnace. Kinney3 found that metal removed from the blast furnace just above the tuyeres contained three to four times as much sulfur as the iron at cast. Herty and Gaines4 conclude that most of the sulfur is removed while the metal is passing through the slag. Mund, Stoecker

Jan 1, 1936

By W. F. Holbrook, T. L. Joseph

The problem of sulfur control is important in all blast-furnace operations but particularly for certain grades of steel because of the rigorous specifications. During the past decade the tendency has been to produce pig iron and hot metal of lower sulfur content. As most of the sulfur in the iron originates in the fuel, the use of high-sulfur coke demands modifications in practice to meet sulfur specifications. While it is generally known that high temperatures and more basic slags favor desulfurization, operators as a rule produce the most acid slag that will permit proper desulfurization. The viscosity of blastfurnace slag has been thought to be related to desulfurization and has been investigated by Feild and Roysterl, also McCaffery and his associates*, but apparently no systematic effort has been made to determine the relative desulfurizing powers of slags over the range of composition encountered in practice. Development of Testing Method Because slag and metallic iron are immiscible, the desulfurization reaction is heterogeneous, occurring only at the interfaces between slag and metal bodies. In the blast furnace the newly reduced iron, containing FeS, descends through the slag bath probably either as small drops or streams, at the interfaces of which desulfurization occurs. After its descent through the slag the iron collects to form a bath of metal, at the top surface of which desulfurization reaction probably occurs. These two steps have been thought to account for all desulfurization in the blast furnace. Kinney3 found that metal removed from the blast furnace just above the tuyeres contained three to four times as much sulfur as the iron at cast. Herty and Gaines4 conclude that most of the sulfur is removed while the metal is passing through the slag. Mund, Stoecker

Jan 1, 1936

Jan 12, 1951

By Edward Keller

GOLD MOVEMENT ON SURFACE OF AURIFEROUS COPPER WHEN LATTER IS SUBJECTED TO OXIDATION SOME years ago the writer's attention was called to the fact that rolling-mill scales from auriferous copper do not have the gold content proportional to the gold contained in the copper from which they are derived. I So, later, he made a few simple experiments, which are described herewith. In: order to test the gold movement on the changing surface of a copper plate under the influence of oxidation, plates 6 in. by 8 in. by I in. (15.2 cm. by 20.3 cm. by 2.5 cm.) of converter copper, refined, of 99.29 per cent. purity, and leaded copper with a content of 95.65 per cent. copper, were obtained. Ten cuts were made through the thickness of the plates along the longitudinal center and the silver and gold content ascertained in each of the 10 samples in both plates, as shown in the accompanying illustration. The assay results, recorded in Tables 1 and 2, show that the gold distribution is relatively uniform in both plates, while silver has greater variations, especially in the leaded plate. The plates subjected to oxidation were placed in a red-hot muffle for about 2 hr., two small scorifiers being used as supports. Arranged alongside each other, they nearly filled the width of the muffle, and so were practically under equal conditions of heat and draft. The accurate observance of the time was not possible, however, because of other work, but the time of the exposure of each plate in a pair was identical. At the end of each period, each plate was plunged into water and completely freed of scale, which was carefully collected, dried, weighed, and analyzed. Samples of the plates had also been taken of the molten metal and duly analyzed. Table 3 contains the analytical data for the two plates and their several sheets, or layers, of oxide scales. These figures show that in the oxidations of the converter copper the silver is fairly uniform, while

Jan 1, 1919

By M. S. Burton, B. W. Christ, G. V. Smith

Evidence of the effects which high-angle grain boundaries and veining subgrain boundaries have on the yield phenomenon of zone-refined iron is reported. Room-temperature tensile tests on 50-mil wive at several gram sizes produced upon recrystallization at diffevent temperatures below 910C (a-y phase-transfornzatzon temperature) show that upper and lower yield stress decrease with increasing grain size. The upper yield point effectively disappears at grain sizes of 81 and 102 u in samples of this diameter. However, samples of 129 p grain size. produced during recrys-tallization at 950°C, exhibit a pronounced upper yield point and an increased lower yield stress. Possible causes of the reversal in the grain-size dependence of yielding are discussed. Veining substructure, detected with picval-HC1 etchant, but not with 2 pct nital, is formed during the a-y transformation, and is believed to account for the observed effecls. The strengthening associated with high-angle boundaries in zone-refined tron is discussed in terms of: 1) the stress dependence of slzp multiplicity, and 2) the stress dependence of dislocation emission from grain boundaries. WIDE use of transmission electron microscopy and dislocation etch-pitting techniques has led to a growing awareness of the presence of dislocation substructures in annealed pure metals. Whereas much speculation'-4 has developed about the influence which subgrain structures have on the mechanical behavior of metals, particularly the yield strength, only limited experimental evidence correlating subgrain structures with lower yield strength has been presented. 2,3,5-7 It is the purpose of this note to present experimental evidence of the effects which grain boundaries and subgrain boundaries have on both the upper and lower yield strength of zone-refined iron. Effects due to high-angle boundaries formed upon recrystallization below the a-y phase transformation are compared with effects due to veining subgrain boundaries formed upon "recrystallization" above the a-y phase-transformation temperature. These effects are further compared with the reported influence 2,3,5-7 which low-angle boundaries have on the lower yield strength of bcc transition metals. EXPERIMENTAL PROCEDURE The starting material for these experiments was a 1-in.-diam zone-refined ingot prepared at Battelle Memorial Institute. Initial purification of electrolytic iron by vacuum-induction melting was improved by a floating zone-melting treatment in ultrapure hydrogen.' Chemical analysis of this zone-refined iron appears in Table I. Tensile samples of 50-mil wire were prepared by rolling and drawing portions of the ingot. An intermediate recrystallization anneal at 625°C after rolling to a reduction in area of 85 pct was carried out in an evacuated Vycor capsule (10-=5 mm Hg). Further reduction in area of 91 pct was followed by recrystallization in evacuated Vycor capsules at temperatures between 600" and 950°C, see Table 111. All samples

Jan 1, 1967

By W. A. Ver Wiebe

It is becoming increasingly apparent that the State of Kansas contains one of the largest reserve areas for oil exploration in the United States. During the year 1936 no less than 54 new oil pools were discovered by drilling. In addition, seven gas pools were found, which may develop into oil pools when deeper horizons are tested. Several old pools increased their reserves when production was found in lower strata. The data presented in Table 2 indicate that nearly 2000 wells were drilled in the state during 1936. Of these more than 1214 found commercial quantities of oil and at least 61 found marketable quantities of gas. The data are conservative because complete results on drilling are not available for the eastern part of the state. Ellis, Rice and Russell Counties share honors with a total of 10 new pools in each. Barton County is prominent with six pools; while those counties claiming fewer new pools are Clark, Ellsworth, Harvey, McPherson, Ness, Pawnee, Rooks, Stafford and Trego. Important additions to our gas reserves were found in Finney and Haskell Counties, which are north of the extensive Hugoton gas area and may some day be part of it. At the close of the year there were 17,317 wells in the state rating as producers. By far the larger share (14,000) were classed as strippers and allowed to flow 100 per cent of their potential capacity, thus accounting for 33,500 bbl. a day. The remaining wells, capable of producing from 15 up to over 6000 bbl. per day, were limited in output according to these amounts. The largest wells having a potential of from 3000 to 7000 were allowed to flow from 2 to 3½ per cent of their official potential capacity. The percentage rises until wells of 15 to 20-bbl. capacity have a rating of slightly over 83. On the basis of these calculations the total potential capacity of all wells was 1,667,814 bbl., and the daily amount allowed was 175,851. Nine of the pools most recently opened were still unable to market their oil and were classified as "shut-in" pools. Total production for the state for 1936 was somewhat over 58 million barrels. Striking Geological Data Some interesting geological data were uncovered by deep drilling during the year. The most remarkable bit of information is the discovery

Jan 1, 1937

By G. U. Greene

The various lead producers have given the subject of lead drosses much attention in recent years but the problem of their economical treatment is yet to be solved. Formerly the copper in the furnace feed was removed from the furnace in the form of matte. The speiss at that time consisted principally of the iron arsenide. The practice today is to roast off most of the sulphur and the copper in the feed forms a dross in the furnace, which is removed from the furnace with the lead. This material is poured into the drossing kettles and allowed to cool down to but slightly above the freezing point of lead. The copper dross, containing almost all of the arsenic and part of the antimony, is skimmed off and treated in a small reverberatory furnace at most plants. This is essentially a liquation process. The skimmed dross contains from 70 to 80 per cent lead, and much of this lead is liquated out. The products from this treatment are: (1) impure lead, (2) speiss and (3) matte. The speiss from the reverberatory furnace was studied in this research. The literature on the subject is of very little assistance, as almost no work has been done on the problem of establishing the exact identity of the various phases present. One author(1)† states that speiss consists of a series of isomorphous compounds of the general formula FexAsy in which the Fe may be replaced by Ni, Co, Cu, Pb, Ag, Au, Pt, Zn, Cd and the As replaced by Sb, S and Bi. Hofman(2) states that the iron arsenide present is Fe5As. Experimental Work In the present research, the author used for methods in an attempt to determine the composition of the various phases: (1) chemical, (2) microscopic, (3) roentgenographic and (4) thermal. Previous to this research, considerable time had been spent making analyses of different speisses, but unfortunately no very definite conclusions could be made as a result of these analyses.

Jan 1, 1937