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By G. A. Mancini, V. Bharucha, J. W. Spretnak, G. W. Powell

The characteristics of the motion of the a interface during the "down" transformation was studied in zone-refined iron and dilute binary alloys containing nickel and molybdenum by means of the thermionic emission microscope and high speed photography. The frontal movements were found in all cases to be definitely discontinuous with time and an appreciable number of incremental jumps were found to proceed in the reverse direction (a to b). Molybdenum was found to be particularly effective in increasing the frequency of the increments of transformation from the stable to the metastable phase. A knowledge of the mechanism by which alloying elements affect the hardenability of a steel is desirable from both the practical and scientific viewpoints. It is well established that microstructures consisting of tempered martensite and lower bainite exhibit the best performance in terms of toughness and resistance to crack propagation. The presence of some upper transformation products, namely ferrite and pearlite, is in general undesirable. Various researches have indicated that the ferrite matrix grain structure is a very important difference between the upper and lower transformation products, namely equi-axed vs acicular. Any comprehensive theory of the decomposition of austenite should explain the dependency of the morphology of the matrix on undercooling. The contribution of various alloying elements to hardenability has been determined experimentally and catalogued in considerable detail. A rationalization of the basic mechanism or mechanisms by which individual elements affect the kinetics of the decomposition of austenite to products other than the phase "martensite" has not been evolved as yet. Interest in this problem was stimulated by the effects of minute quantities of boron in hardenable steels. This paper deals with one aspect of this problem, namely the characteristics of the ?-a transformation in high-purity iron and in two carbon-free iron binary alloys. A detailed historical account of the scientific developments in the study of the decomposition of austenite would be a prodigious undertaking and will not be attempted here. There are several excellent reviews in the literature on the formation of pearlite, martensitic reactions, and kinetics of solid-state reactions. The thinking on reaction mechanisms has been influenced to a large degree by the "classical" Tammann nucleation and growth model, in which an embryo springs into being by a fluctuation, and grows to a critical size through atom by atom deposition. Such a process is expected, accordingly, to be diffusion controlled. Considerable research attempting to relate the contribution of alloying elements to hardenability on the basis of their effect on the diffusivity of carbon in iron has not been productive from a mechanistic viewpoint. The formation of pearlite and ferrite has been treated in terms of nucleation and growth processes in which presumably the lattice transformation also occurs by a diffusion process. The other prominently considered mechanism is the "martensitic" or cooperative shearing mechanism. It seems generally, but not entirely, agreed that the phase "martensite" forms by this mechanism, and that it is involved to some extent in

Jan 1, 1962

By W. J. Uren, Charles R. Kuzell

The industries engaged in winning minerals from the earth, because of their widespread dissemination, are faced with perhaps as wide a variety of labor-management problems as may be found in any other broad sphere of productive activity. Those problems are continually increasing in volume and complexity, and management has become aware of their growing importance. For the past quarter century at least, labor-management problems have largely been union-management problems. During this period tremendous assistance has been given labor unions through legislation and administrative and political action. In the United States, legislation favorable to unions has come about in the form of the now defunct National Industrial Recovery Act; the Wagner Act, most of which has been carried forward in the Taft-Hartley Act and the Landrum-Griffin Act; the Norris-La Guardia Act, the Wage and Hour Law, the Walsh-Healey Act, and others. The result has been to transfer from the hands of management to those who direct the affairs of the unions a large share of control over the industry and to hamper in many ways the remaining control left to management. In the United States there are many examples of the power of unions to injure whole industries seriously without regard to the interests of management, the employes, or the public. During 1958 and 1959 revelations of corruption and coercion in labor unions made before the McClellan Committee of the U. S. Senate generated considerable public sentiment in favor of legislation to protect the interests of employes and the public. However, the resulting legislation, the Labor-Management Reporting and Disclosure Act of 1959 (Landrum-Griffin Act), demonstrated quite clearly that the political power of the labor union leaders was adequate to prevent adoption of effective measures in this field.

Jan 1, 1964

By Charles B. Dudley

THEO. N. ELY, Esq., Superintendent of Motive Power. DEAR SIR: It is now nearly three years since my first report to you on the subject of steel rails was written. That report, as you will remember, dealt principally with the question of the relation between the chemical composition and physical properties of steel rails and their power to resist crushing and fracture in actual service. Other matters were referred to or touched upon in that report, but the main question was, Why do some rails crush or break in service while others do not? You will doubtless remember that the principal conclusion arrived at was, that the softer rails are less liable to crush or break in service than the hard ones. Or, in other words, so far as conclusions could be drawn from the chemical analysis and physical test of 25 samples of steel rails which had actually been in service, these conclusions were that those rails which have the smaller amounts of carbon, phosphorus, silicon, and manganese are less liable to crush or break in service than those which have larger amounts of these elements. Or, again, looked at in the light * At the Lake George meeting of the Institute in October, 1878, I had the honor of presenting to the Institute, through the kind permission of the officers of. the Pennsylvania Railroad Company, the results of a study of twenty-five samples of steel rails, which had all been in actual service. Considerable discussion followed the publication of that paper, and there seemed to be a strong disinclination, especially on the part of the steel-rail manufacturers, to accept the conclusions presented. One of the principal objections urged against the conclusions drawn was, that they were based on too few samples; in other words, that no conclusions safe to act upon could be drawn from the examination of twenty-five rails. In view of this criticism it was decided to repeat the investigation with a larger number of samples, and with the aid of the experience gained in the first investigation. The results of this second study of steel rails are, by the permission of the officers of 'the Pennsylvania. Railroad Company, herewith presented to the Institute, with the sincere desire that they may aid in adding to our knowledge of this most important product. Like the previous paper, this is in the form of a report to one of the officers of the company, which will account for the style, and the manner of presenting the data

Jan 1, 1881

By C. Norman Bowers, Blaine B. Wescott

Marked improvement in the serviceability of sucker rods has been effected in the last two years, partly because of the insistent necessity for greater economy in the operating costs of crude oil production growing out of the general industrial depression and partly because many of the recently developed fields have imposed more severe operating conditions upon both surface and underground equipment. The latter is particularly true of Kansas, where practically all of the oil produced is associated with damaging amounts of hydrogen sulfide brine and where the method of establishing potential production demands equipment capable of being operated at maximum capacity without interruptions. The decline of flush production in the Oklahoma City field created new problems in deep-well pumping on a scale heretofore unequaled and the increased proportion of water it has been necessary to produce in the fields of the Greater Seminole area presented conditions that were acutely in need of betterment. The problem in the latter fields was complicated by the shift towards sulfide characteristics, which accompanied water encroachment, and it is probably true that nowhere, at the present time, are pumping conditions generally as severe as in this territory. The Mid-Continent district, therefore, has become the proving ground for the numerous materials that have been proposed for sucker-rod fabrication. The information that ultimately will be obtained from an unprecedented amount of field experimentation will pay ample dividends when the decline of East Texas increases the demand for the vast reserves of sour crude in West Texas. It is a rare occurrence in industry that the use of such a simple piece of equipment as a sucker rod presents so complicated a problem for solution. As proof of this, it is only necessary to consider the numerous types of sucker rods on the market at the present time and contrast this condition with that of less than four years ago, when it was the common aim of manufacturers to develop a single sucker rod for all conditions of

Jan 1, 1935

By Charles H. Eldridge, Robert J. Anderson

When a metal or alloy is poured into a mold, internal stresses are set up by the cont,raction in volume on passing from the liquid state at the temperature of pouring to the solid state at the ordinary temperature. It is assumed by the writers that all castings are internally stressed. That any casting is internally stressed is shown by its warping or distortion on maturing at the ordinary temperature, by warping or cracking on heating, or by cracking or distortion on machining. In the investigation made by the writers, the internal stresses in cast non-ferrous alloys were studied with a view to examining the effects of heat treatment (i.e., simple anneal) on the release of such stresses. Data have been obtained that show quantitatively that internal stresses can be removed by appropriate heat treatment. The investigation was limited to a study of the effect of heat treatment on stress release in cast rings of the 87:7:5:1 copper-tin-zinc-lead alloy. The writers are indebted to E. G. Fahlman for the method used for inducing stress in cast rings; to M. E. Boyd for microscopic examination and for other aid; and to G. B. Dalrymple for the chemical analyses. General Information While casting stresses have been discussed considerably, they have usually been treated in a general way, and so far as the writers know no measurements of the magnitude of internal stresses in castings have been reported. It has been suggested by many investigators, particularly in the case of steel castings, that castings are internally stressed, and that these stresses can be removed by annealing. In a casting, the internal

Jan 1, 1923

By Robert J. Anderson, Charles H. Eldridge

When a metal or alloy is poured into a mold, internal stresses are set up by the cont,raction in volume on passing from the liquid state at the temperature of pouring to the solid state at the ordinary temperature. It is assumed by the writers that all castings are internally stressed. That any casting is internally stressed is shown by its warping or distortion on maturing at the ordinary temperature, by warping or cracking on heating, or by cracking or distortion on machining. In the investigation made by the writers, the internal stresses in cast non-ferrous alloys were studied with a view to examining the effects of heat treatment (i.e., simple anneal) on the release of such stresses. Data have been obtained that show quantitatively that internal stresses can be removed by appropriate heat treatment. The investigation was limited to a study of the effect of heat treatment on stress release in cast rings of the 87:7:5:1 copper-tin-zinc-lead alloy. The writers are indebted to E. G. Fahlman for the method used for inducing stress in cast rings; to M. E. Boyd for microscopic examination and for other aid; and to G. B. Dalrymple for the chemical analyses. General Information While casting stresses have been discussed considerably, they have usually been treated in a general way, and so far as the writers know no measurements of the magnitude of internal stresses in castings have been reported. It has been suggested by many investigators, particularly in the case of steel castings, that castings are internally stressed, and that these stresses can be removed by annealing. In a casting, the internal

Jan 1, 1923

By George S. Rice

The A.I.M.E. Ground Movement and Subsidence Committee, proposed in 1920, held its first technical meeting in February 1923, under the able chairmanship of Mr. H. G. Moulton. The following list of papers and discussions, indicating the scope of the problems and relation to various conditions and method of mining, were given at that meeting by the distinguished mining engineers: J. Parke Channing, on Subsidence at Miami, Arizona; Howard N. Eavenson, on Mining an Upper Bituminous Seam after a Lower Seam Has Been Extracted; J. J. Rutledge, on Subsidence in Two Oklahoma Coal Mines; Benjamin F. Tillson, on Caving Cracks at the Franklin Mine, New Jersey; Dr. F. W. McNair, on the Dome Theory; William Kelly, on disadvantageous effects in Mining and Back-filling Working Upward a Steep-Pitching Iron-ore Bed; Eli T. Conner, on the good results of Back-Filling by Hydraulic Means in Preventing Destructive Subsidence in the Anthracite District; Thomas H. Claggett, on the merit of Systematic Pillar Drawing in Preventing Cracks in an Upper Seam; Henry H. Otto, successful results in the anthracite district in Mining Lower Seams before Upper Seams; Douglas Bunting, on Leading Factors Incident to Successful Mining of an Overlying Seam; Edwin Ludlow, on there being "less damage to buildings when there was complete removal of coal with complete packing than when room and pillar is used without extracting the pillars"; Edward O'Toole on "bumps" in eastern Kentucky mines, which he thought were the result of geologic stresses: H. A. Buehler, on Upheaval of Surface in an Illinois Case in Advance of the Face; and R. Dawson Hall, on The Mechanics of Subsidence from Mining. The author of this paper discussed various kinds of problems of ground movement and subsidence in both metal mining and coal mining; the production of great landslides by workings near an outcrop, as at Turtle Mountain, Alberta, Canada; and general

Jan 1, 1940

By George S. Rice

The A.I.M.E. Ground Movement and Subsidence Committee, proposed in 1920, held its first technical meeting in February 1923, under the able chairmanship of Mr. H. G. Moulton. The following list of papers and discussions, indicating the scope of the problems and relation to various conditions and method of mining, were given at that meeting by the distinguished mining engineers: J. Parke Channing, on Subsidence at Miami, Arizona; Howard N. Eavenson, on Mining an Upper Bituminous Seam after a Lower Seam Has Been Extracted; J. J. Rutledge, on Subsidence in Two Oklahoma Coal Mines; Benjamin F. Tillson, on Caving Cracks at the Franklin Mine, New Jersey; Dr. F. W. McNair, on the Dome Theory; William Kelly, on disadvantageous effects in Mining and Back-filling Working Upward a Steep-Pitching Iron-ore Bed; Eli T. Conner, on the good results of Back-Filling by Hydraulic Means in Preventing Destructive Subsidence in the Anthracite District; Thomas H. Claggett, on the merit of Systematic Pillar Drawing in Preventing Cracks in an Upper Seam; Henry H. Otto, successful results in the anthracite district in Mining Lower Seams before Upper Seams; Douglas Bunting, on Leading Factors Incident to Successful Mining of an Overlying Seam; Edwin Ludlow, on there being "less damage to buildings when there was complete removal of coal with complete packing than when room and pillar is used without extracting the pillars"; Edward O'Toole on "bumps" in eastern Kentucky mines, which he thought were the result of geologic stresses: H. A. Buehler, on Upheaval of Surface in an Illinois Case in Advance of the Face; and R. Dawson Hall, on The Mechanics of Subsidence from Mining. The author of this paper discussed various kinds of problems of ground movement and subsidence in both metal mining and coal mining; the production of great landslides by workings near an outcrop, as at Turtle Mountain, Alberta, Canada; and general

Jan 1, 1940

By T. L. McCall

The late Walter Herd1 in 1929 gave a full description of past and present conditions in No. 2 mine, Springhill, Nova Scotia, developed theories regarding the cause of these bumps and made certain suggestions regarding possible methods of future development. Recapitulating briefly from Mr. Herd's paper, the seam is bituminous coal, averages 9 ft. in thickness and has a well defined parting containing fusain about 14 in. from the roof. This roof coal is somewhat stronger than the rest of the seam and has a tendency to cling to the roof. The pitch of the seam where it is now being worked is about 20". The first manifestations of bumps began when the room and pillar workings had reached a depth of cover of 1900 ft. and under continuously increasing depth of cover these bumps increased to such an extent, both in number and severity, that in the year 1924 it became apparent that some change in the system of extraction was necessary. After closely studying all the factors involved and benefiting largely by valuable outside advice obtained by the Provincial Department of Mines of Nova Scotia,2 the system of working was changed from room and pillar to longwall retreating. Mr. Herd's paper described in detail three remarkable bumps in the year 1928 in April, July and October that affected the 5700-ft. and 5900-ft. East levels, the last bump being so severe both in intensity and in extent of damage done that this district was abandoned. The longwall workings to the west of the slope had been stopped in the year 1926 owing to an inbreak of water, coming from the flooded waste of No. 3 seam lying some 400 ft. vertically overhead. This inflow was not excessive, but a large quantity of water being impounded in the old workings it was considered advisable to take the prudent course and not incur the risk of possibly increasing the flow by further working. This district has remained idle ever since.

Jan 1, 1934

By A. W. Dana, F. J. Shortsleeve, A. R. Troiano

The phenomenon of flake formation which may occur during cooling or room temperature aging of large steel sections is caused by a combination of hydrogen and stress. As such, the transformation characteristics of austenite in a particular section play a major role in the occurrence of flakes. Isothermal and continuous cooling studies demonstrated that flake formation is particularly sensitive to nature, distribution, and relative proportions of the microconstituents in the cooled sections. In the absence of transformation stresses, abnormally high hydrogen contents could be tolerated without flaking. Flakes were not found in the absence of transformation stresses. No correlation existed between average hydrogen content and flake formation where cooling stresses were low. Hydrogen in the steel was a necessary but not sufficient condition for flake formation. DESPITE a long history of laboratory and commercial investigations, the mechanics of hairline crack or flake formation in large steel sections remains unresolved. Recent publications1-5 emphasize that flaking is still a serious problem.* immediate cause of flaking is the pressure exerted by entrapped hydrogen gas that collects in small internal cavities or voids during cooling. When the temperature of steel is low enough to preclude extensive plastic flow, the cavity pressures cause local brittle fractures (flakes). 2—The microsegregation and transformation stress theory. According to this theory, flaking results from stresses arising from the volume changes accompanying the formation of martensite and/or low temperature bainite after a large portion of the section has transformed at elevated temperatures. The proponents of the hydrogen theory suggest that stresses from other sources may be additive to the stresses produced by hydrogen and may, in some cases, provide the increment of stress necessary to produce flakes. However, the critical aspect of this theory is that no stress, except that produced by hydrogen pressure, is believed to be sufficient in itself to produce flakes. For practical considerations, this means that the only safe thermal cycle is one that reduces the hydrogen content to some low critical level below which flaking will not occur regardless of the state of transformation. On the other hand, the transformation stress theory does not rule out the embrittling effect of hydrogen. This theory simply proposes that flaking does not occur in the absence of transformation stresses. With the transformation stress theory as a basis, commercial antiflaking cycles would be designed to complete the transformation of austenite prior to cooling to ambient temperatures. Both of these theories appear compatible with industrial experience. Antiflaking cycles, such as cooling at extremely conservative rates or soaking for periods of time in the upper subcritical temperature ranges prior to cooling to ambient temperatures, may allow the following: 1—diffusion of hydrogen out of the section and, as a consequence, reduction of the hydrogen content to some safe minimum value (hydrogen pressure theory) and 2—complete decomposition of the austenite at rela-

Jan 1, 1956

By H. F. Silliman, Daniel R. Hull, John R. Freeman

In the normal operation of a brass-rolling mill, sheet and strip has, for the most part, been finished in comparatively thin gauges, involving a substantial amount of cold-work and a considerable number of anneals. This condition has been disturbed by the preponderance of cartridge brass, which is not rolled to thin gauges, and particularly by brass for artillery cartridge cases, on which the mill may finish its work at a thickness between 0.400 and 0.900 in. Obviously, the amount of rolling and the number of anneals to which such a product can be subjected are small compared with strip that is carried to a thickness of a few hundredths of an inch. As a result, critical examination into the internal condition of metal has been made on an extensive scale at a stage of manufacture that would not, in normal times, have been chosen for complete inspection. Under these conditions, a type of defect has been recognized that is not seen at thinner gauges. It might be more accurate to call it the appearance of a defect, since it refers to an apparently laminated, discontinuous structure, which, in fact, does not exist as such, and disappears after suitable treatment. For this reason it has been called a phantom lamination, which the authors consider an appropriate term. It is the purpose of this paper to describe the phenomenon and the conditions of its occurrence and, at least tentatively, to discuss its nature and cause. Great numbers of phantoms may be found in 2:r brass, either hot-rolled or cold-rolled. They are also found in 70-30 brass, sometimes when hot-rolled and generally when cold-rolled. It is not believed that phantoms are confined to these alloys but this paper is limited to them for the purpose of description. Hot-rolled 2:1 Brass For illustration, therefore, a typical cake of hot-rolled 2:I brass has been chosen. This was rolled to a slab 36 in. thick, from a casting 5 in. thick by 24 in. wide by 18 in. high, which was believed to have been sound. After hot-rolling and cooling, the slab was sheared and a portion of such a shear cut is shown in Fig. I. It would be difficult to convince anyone viewing this specimen that the metal was not unsound. The impression would be confirmed by the appearance of a tensile break, as shown in Fig. 2. This is an ordinary tensile-test piece from metal just described. Although there was nothing in its tensile strength or elongation that suggested unsoundness, it appeared run through with pipes and laminations. To question the reality of such a condition would imply questioning the obvious. But, considering the history of the metal, it would be difficult to believe that it could be so bad as it appeared. It seemed reasonable, though, that if the defects were what they appeared to be, they could be traced back from the sheared or broken face.

Jan 1, 1945

By N. J. Grant, A. W. Mullendore, Y. Ishida

Creep tests were performed at 500°F on polished specimens of A1-3 pct Cu at stresses of 2000, 4000, and 6000 psi. The effects of the size and distnbution of the second phase were studied in connection with the mechanisms of deformation, especially grain boundary sliding. Although the amount of grain boundary sliding varied considerably for the different heat treatments, yestriction of grain boundary sliding is not due primarily to precipitate on the grain boundary. NUMEROUS prior investigations of grain boundary sliding, notably those of McLean, 1 Rachinger, 2 Rhines, Bond, and Kissel, 3 and Brunner and Grant,4 have established the importance of this phenomenon in the deformation of pure aluminum and its solid-solution alloys at elevated temperatures. An extension of this kind of study to the case of a simple two-phase structure is an important step towards understanding the deformation behavior of more complex alloys. A two-phase A1-3 pct Cu alloy was selected for this study. The creep behavior of alloys in this system has been studied by Sully and Hardy,5 by Underwood, Marsh, and Manning,' and by Pelloux, Chaudhuri, and Grant.7 In these studies, the prior heat treatments were such that some precipitation took place during the tests in most cases. Pelloux, Chaudhuri, and Grant7 studied the creep of A1-2 and 3 pct Cu alloys in the overaged condition. Their results indicated that the structure most effective in promoting high-temperature strength consisted of a fine, closely spaced grain precipitate and large, widely spaced particles on the grain boundary. The present work consists of quantitative meas- urements of grain boundary sliding during creep of an A1-3 pct CU alloy with four different precipitate distributions. The aims were to quantitatively define the role of the second phase on grain boundary sliding, and to obtain information regarding the mechanism of grain boundary sliding. MATERIALS AND PROCEDURE A high-purity A1-3 pct Cu alloy, kindly supplied by Alcoa, was used in this investigation. The composition of the alloy in weight percent was as shown in Table I. This composition is such that A12Cu exists as a second phase at temperatures below 850°F. A homogeneous grain size of 0.6 to 0.8 mm was obtained by annealing the machined test bars for 5 min at 1000°F, furnace cooling to 930°F, and homogenizing for 5 hr. Following the recrystalli-zation and homogenizing anneal, four different heat treatments shown in Fig. 1 were utilized. The F7 and F5 treatments utilize a furnace cool to the aging temperature while Q7 and Q5 have a water quench from the homogenization temperature before aging. Figs. 2 to 5, and Table 11, show the size and shape of precipitate dispersions obtained with the above heat treatments. The heat treatments produce variations in the dispersion both in the grains and along the grain boundaries. Precipitate particles along the grain boundaries are rounded and large (about 1.5 p diameter) in the F5 and F7 structures (Figs. 3 and 5). The grain boundary precipitate was somewhat smaller (0.9 p diameter) in the Q7 structure and no grain boundary precipitate was detected in the Q5 structure using light microscopy. The pre-

Jan 1, 1964

By C. Wert, D. Keefer

The results of this study indicate that sudden increases in aging temperature lead to reversion phenmena in carbon in the a, iron system. These phenomena are thought to be associated with the dissolution of carbide precipitates. Reversion is studied with respect to three variables: 1) Specimen grain size, 2) the initial amount of carbon in solution, and 3) difference between initial and final aging temperature. It is found that of these variables the initial carbon concentration has the greatest effect on reversion. THE solid solution of carbon in n iron has been the subject of numerous investigations throughout the past few years. Despite the great amount of effort which has been put forth toward understanding this system, however, there persist a number of interesting aspects of the system which are open to further research' Studies Of the precipitate which forms as a result of aging a supersaturated solution of carbon in a, iron appear to be particularly interesting. The present work is an attempt to determine certain

Jan 1, 1960

By S. A Weigand, J. W. Bolton

Production of sound bronze castings is a matter of great practical interest to users and manufacturers of high-grade non-ferrous engineering specialties. Although there has been much excellent research in this field, there still remains some confusion regarding the fundamental principles underlying production of really sound bronze. The literature of the past 20 years on this subject indicates that the prevailing opinion of metallurgists and foundrymen has been that unsoundness in bronze is due generally to oxidation. The following references are typical. Review of Literature Carpenter and Edwards1 state that when gun metal is melted the alloy dissolves gas, the amount increasing with rise in temperature and duration of the melting. The solubility of the gas diminishes during the fall in temperature and it escapes through the liquid metal. At the moment of incipient solidification there is an evolution of gas. Sperry2 says that by using charcoal a reducing atmosphere is supplied whereby oxidation is prevented, and this also prevents gases from coming in contact with the metal. Logan3 says that many of the troubles that occur in non-ferrous castings are the direct result of one thing—oxidized material. He mentions how readily copper absorbs oxygen when molten, but does not mention the harmful effects of reducing conditions as observed in overpoled copper. Guillemin and Delachana14 investigated the gases occluded in bronze and found that the better bronzes contained mostly hydrogen while the poorer ones had a larger proportion of carbon monoxide and carbon dioxide.

Jan 1, 1929

By J. W. Bolton, S. A. Weigand

Production of sound bronze castings is a matter of great practical interest to users and manufacturers of high-grade non-ferrous engineering specialties. Although there has been much excellent research in this field, there still remains some confusion regarding the fundamental principles underlying production of really sound bronze. The literature of the past 20 years on this subject indicates that the prevailing opinion of metallurgists and foundrymen has been that unsoundness in bronze is due generally to oxidation. The following references are typical. Review of Literature Carpenter and Edwards1 state that when gun metal is melted the alloy dissolves gas, the amount increasing with rise in temperature and duration of the melting. The solubility of the gas diminishes during the fall in temperature and it escapes through the liquid metal. At the moment of incipient solidification there is an evolution of gas. Sperry2 says that by using charcoal a reducing atmosphere is supplied whereby oxidation is prevented, and this also prevents gases from coming in contact with the metal. Logan3 says that many of the troubles that occur in non-ferrous castings are the direct result of one thing—oxidized material. He mentions how readily copper absorbs oxygen when molten, but does not mention the harmful effects of reducing conditions as observed in overpoled copper. Guillemin and Delachana14 investigated the gases occluded in bronze and found that the better bronzes contained mostly hydrogen while the poorer ones had a larger proportion of carbon monoxide and carbon dioxide.

Jan 1, 1929

By W. A. Backofen, D. Lee

The deformation of textured sheet of titanium and several of its all-a (hcp) alloys was investigated with two kinds of experiments: tension testing along different directions in the plane of the sheet, and combined-stress loading along the principal axes of anisotropy (the rolling and transverse directions). Texture and plastic anisotropy were evaluated with pole figures and by measurement, as a function of orientation, of the tensile transverse-strain ratio, or R parameter. The results as a whole can be rationalized qualitatively with the present understanding of deformation mechanisms in titanium. Quantitative agreement between the orientation dependence of tensile yield strength and the Predictions of continuum ANISOTROPY in the properties of engineering materials is more the rule than the exception because anisotropy in structure is so common, and the one generally follows the other. Two broad categories of structural anisotropy are represented by mechanical fibering and crystallographic texture. The former is important in many aspects of fracture.' The latter has more significance for yielding and plastic deformation, theory, using the R measurements, was relatively poor. However, in tension-tension quadrants of the yield-locus diagrams, the difference between theory and experiment was hardly more than 10 pct. The maximum texture-hardening effect was found in a 4Al-1/4O2 alloy to be nearly 50 pct. In the compression-compression quadrant, {1012} deformation twinning prevented the locus from expanding much beyond the Position predicted for isotropic material. With increasing temperature the trend in R was downwards, approaching unity (isotropy) near the a-transus temperature; an accompanying development was large amounts of neck-free extension. which are of special concern in this paper. The tendency has been to view crystallographic texture more as a liability or curio than as an asset. The prominent exception is found in silicon-ferrite sheet for power-transformer cores, which is processed to develop a new optimum texture for high electrical efficiency. Yet it should be possible to find other examples, involving other kinds of properties. More specifically, there is good analytical reason to expect improved combined-stress yielding resistance in suitably textured material,2,3 and it has now been shown by experiment that texture hardening or softening is a potentially useful phenomenon in certain engineering devices and processes.'-I To date, work has included measurements of the transverse (width to thickness) strain ratios in the

Jan 1, 1967

By J. D. Grozier, W. W. Mullins, H. W. Paxton

The morphology of the nucleation and growth of austenite into high-purity iron in NH3-H2, gas mixtzires has been studied. The growth rate of an austenitic rim (planar interface) from scratched surfaces of- polycrystalline iron specimens was determined as a function of temperature and percent NH3 and found to he in reasonahle agreement with growth-rate calculations based on a model which assumes the diffusion of nitrogen to he the rate-controlling step. Under certain conditions, austenite pew as platelets; growth rates of these along the surface of single crystals were found to he dependent on surface preparation, orientation, THE development of microstructures can conveniently be thought of in terms of nucleation and growth. The complex topic of nucleation in solid-solid transformations will not be discussed at length, although a few qualitative experiments were performed. Growth is determined by the mobility of the various possible interfaces under the available driving forces in a particular situation. In homophase transformations, it has been clearly demonstrated that the mobility is very sensitive to small amounts of impurities, to the kind of impurity, and to the orientation relations across the boundary.' A degree of quantitative knowledge has temperature and percent NH3. On electropolished surfaces with a (110) pole, the maximum growth rate of platelets was determined and found to be in agreement within a factor of 2 to 3 with theoretical calculations of the edgewise growth rate of a platelet. The calculations are based on a model which assumes that the diffusion of nitrogen in the ferrite in front of the moving curved attstenitic interface at the tip of the platelet is the rate-controlling step. The growth direction on the surface of the single crystal and resztlting habit plane of the platelets were determined and found not to he unique but to vary systematically with the pole of the surface. been obtained. In the case of heterophase transformations, which are significantly more complicated to treat, a comparison of theoretical and experimental studies often shows rather poor agreement.'-' The main purpose of the experiments discussed below was to obtain additional quantitative data on crystallographic effects on boundary mobility in a system which was otherwise as simple as possible, viz. the growth of iron-nitrogen austenite into fer-rite. In the course of the experiments, it became necessary to re-examine the theory for the growth of Widmanstatten plates, especially the influence of anisotropic interfacial free energy. Some other minor experiments in the Fe-N system were performed, and are described briefly. EXPERIMENTAL METHODS A) Material Preparation. The floating zone purified iron used for this investigation was supplied by Battelle Memorial Institute. The nominal composi-

Jan 1, 1965

By H. F. Winham

The history, development, subsurface geology, production, economics and estimated reserves are discussed in this paper. The Magnolia structure is an anticline with a known maximum structural relief at 372 ft., and the areal extent of the producing acreage is 4494 acres. Production is obtained from the Smack-over oölitic lime and 116 successful wells have been drilled. The field, which was developed on 40-acre spacing, has been under strict control. It is believed to be producing with a strong water drive, To date it has produced more than eighteen million barrels and the estimate of ultimate recovery is 220 million barrels. Early History The Magnolia field is in colurnbia County, Arkansas, T. 17 s., R. 19 and 20 W. Various geologists had long been interested in this general area, and as early as 1921, John F. Magale was able to define a surface structure. The first wildcat, one of the first in Columbia County, was drilled in 1923 by Mid-States Oil Co., in sec. 10, T. 17 S., R. 20 W. This well was about 11/2 miles northwest of the Kerlyn oil Company's discovery well and was based on surface geological work done by Jewel and Dobie. Subsequently, several shallow wells that were not carried below the Upper Cretaceous beds were drilled in the immediate area of the discovery well, but none of them contained any commercial showings of oil Or gas. In the latter part of 1935, Elam and Magale (or Southwood) Garrett NO. I was located in sec. 13, T. 17 S., R. 20 W., 3/4 mile east of the discovery well. It was drilled to a total depth of 4018 ft. in the lowermost Glen Rose beds but failed to obtain any showings of oil or gas. Interest had been stimulated in this general area, however, by the discovery of several oil fields, mainly Glen Rose oil production in the Rodessa field in Louisiana in 1935, Smackover lime productioil in Snow Hill in May 1936, production from the Cotton Valley formation in Schuler in 1937, and Smackover lime production from the Buckner field in November 1937. With this background and subsequent seismic work, which was carried on partly because the old shallow wells drilled in the township had shown evidence of closure in the Upper Cretaceous beds, the discovery well, Kerlyn Oil Company's Barnett No. I, Sec. 14, T. 17 S., R. 20 W., was originally projected to a total depth of 6300 ft., to test the equivalents of the Morgan sands of the Cotton Valley series, then producing at Schuler. The well was carried to a depth of 6325 It. and tested the objective beds without finding commercial production. In the meantime, however, one well had found production in the Jones sand and another in the Smaclrover lime at Schuler. Kerlyn immediately made arrangements to deepen the Barnett well to the Smackover lime. The top of the Smackover lime was encountered at 7618 ft. and the well

Jan 1, 1943

By H. F. Winham

The history, development, subsurface geology, production, economics and estimated reserves are discussed in this paper. The Magnolia structure is an anticline with a known maximum structural relief at 372 ft., and the areal extent of the producing acreage is 4494 acres. Production is obtained from the Smack-over oölitic lime and 116 successful wells have been drilled. The field, which was developed on 40-acre spacing, has been under strict control. It is believed to be producing with a strong water drive, To date it has produced more than eighteen million barrels and the estimate of ultimate recovery is 220 million barrels. Early History The Magnolia field is in colurnbia County, Arkansas, T. 17 s., R. 19 and 20 W. Various geologists had long been interested in this general area, and as early as 1921, John F. Magale was able to define a surface structure. The first wildcat, one of the first in Columbia County, was drilled in 1923 by Mid-States Oil Co., in sec. 10, T. 17 S., R. 20 W. This well was about 11/2 miles northwest of the Kerlyn oil Company's discovery well and was based on surface geological work done by Jewel and Dobie. Subsequently, several shallow wells that were not carried below the Upper Cretaceous beds were drilled in the immediate area of the discovery well, but none of them contained any commercial showings of oil Or gas. In the latter part of 1935, Elam and Magale (or Southwood) Garrett NO. I was located in sec. 13, T. 17 S., R. 20 W., 3/4 mile east of the discovery well. It was drilled to a total depth of 4018 ft. in the lowermost Glen Rose beds but failed to obtain any showings of oil or gas. Interest had been stimulated in this general area, however, by the discovery of several oil fields, mainly Glen Rose oil production in the Rodessa field in Louisiana in 1935, Smackover lime productioil in Snow Hill in May 1936, production from the Cotton Valley formation in Schuler in 1937, and Smackover lime production from the Buckner field in November 1937. With this background and subsequent seismic work, which was carried on partly because the old shallow wells drilled in the township had shown evidence of closure in the Upper Cretaceous beds, the discovery well, Kerlyn Oil Company's Barnett No. I, Sec. 14, T. 17 S., R. 20 W., was originally projected to a total depth of 6300 ft., to test the equivalents of the Morgan sands of the Cotton Valley series, then producing at Schuler. The well was carried to a depth of 6325 It. and tested the objective beds without finding commercial production. In the meantime, however, one well had found production in the Jones sand and another in the Smaclrover lime at Schuler. Kerlyn immediately made arrangements to deepen the Barnett well to the Smackover lime. The top of the Smackover lime was encountered at 7618 ft. and the well

Jan 1, 1943

By F. E. Streigert, J. H. Mallery, A. H. Geisler

The existing data on precipitation in Cu-Be alloys have been reconciled with some new data to present a more complete and rational analysis of the atomic rearrangements involved in the process. Two different coherent precipitates were proposed. Each is responsible for a type of diffuse X-ray diffraction effect. THE nature of the atomic rearrangement involved in the precipitation of the compound y-Cu-Be from supersaturated solid solutions of the copper-base alloys has been the subject of two extensive investigations.'-" he precipitate in this alloy system has a rather simple structure; at equilibrium it has a body-centered cubic unit cell with copper atoms on the corner sites and beryllium atoms on the center site. While a simple mechanism would be expected to obtain for the precipitation process, those which have been proposed do not adequately explain all of the reported data. The purpose of the present report is to rationalize some of the previous observations and to contribute new data on the subject obtained by the usual techniques of structure analyses. The Cu-Be system of alloys represents one of the most extensively investigated precipitation systems, so a detailed review of the pertinent literature on structure is in order. Striations: Since one of the important features of the mechanism—the habit plane—is determined by microscopic examination, microstructural features that have been observed should be considered at this time in order to assess their role in the precipitation process in Cu-Be alloys. One of the most prominent features appears as regularly oriented markings or stripings (ripples or striations) across the crystals on a suitably polished and etched sample of the aged alloy. These have been observed and interpreted by many workers. Masing and Dah14 observed striations in both the a and /3 phases of a 2.5 pct Be alloy, and attributed them to the beginning of the precipitation of very fine y crystals along favored planes of the a matrix and to the local decomposition of the £ crystals into a plus y. These markings were apparent in both the a and /3 phases of the micrographs given by Smith5 for a 2.75 pct Be alloy, while Moore" detected them in the a matrix phase using polarized light. Desch7 attributed the markings to fine precipitate particles lined up on a family of matrix planes like Masing and Dahl had done, and he identified the planes as those of the (111) family, the slip planes of the matrix. The striations were presumably the structure which Northcott- eferred to as "martensitic." He found that this structure was present in samples that had been aged under widely different conditions with hardness values ranging from 160 to 400 VHN. Later Guinier and Jacquet' also found striations in both the a matrix and secondary /3 phase. Their analyses showed that the striations were along (110) planes of the matrix phase, apparently in contradiction of the results of Desch. They found that the striations were developed during aging on the surface of a specimen that had been polished prior to aging.' On this basis they concluded that the striations represented mechanical deformation by slip along (110) planes of the matrix resulting from precipitation stresses.'" Similar but fainter striations were observed in the same manner on an A1-Cu alloy sample, in which the change in volume was much less than for Cu-Be alloys and

Jan 1, 1953