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By FRANK COLE

THE territory covered in this discussion includes all the states west of the Mississippi river. Agriculture is expanding each year in this section, but until recent years the application of commercial fertilizers as an aid to crop production was not practised to any great extent. The use of commercial fertilizers has increased somewhat, but is still on a small basis as compared with the tonnages used else- where in the United States. During 1928 these western states used 665,100 tons of all classes of fertilizer as compared 'with 7,933,600 tons used in the whole United States; or this western area, compromising near- ly two-thirds the land area, uses about 5 per cent of the total fertilizer. To show how large a tonnage one state may consume, North Carolina for the year 192s used 1,349,360 tons of commercial fertilizer or about twice the amount used by 22 western states.

Jan 1, 1930

By Carl F. Floe, John Chipman

A YEAR ago the authors published a paper on the solubility of sulphur dioxide in molten copper.1 The data in that paper agreed closely with that obtained by previous investigators, which, however, did not agree with the theoretical predictions for solubility of triatomic gases of this type. It has generally been assumed that the reaction of solution is: [ ] Neglecting the slight change in copper concentration and considering that the concentrations of sulphur and oxygen are both proportional to the volume of gas absorbed, it follows that this volume should be proportional to the cube root of the pressure. It was found that a plot of the volume absorbed versus the cube root of the pressure gave a straight line, but that this line did not pass through the origin. Calculations of the equilibrium constant for the reaction showed that it was fairly constant for pressures above l00 mm. but that actually it approached zero at lower pressures. The conclusion was made therefore that the solubility as determined could not be expressed by Eq. I or by any other simple equation, particularly at low pressures. Other investigators have concluded that the solubility of sulphur dioxide in copper as well as in several copper alloys is more nearly proportional to the square root of the pressure.* Such a conclusion, however, does not satisfactorily account for the results, even when rather complicated mechanisms for the solution are assumed. The highly improbable speculations of Lepp2 and of Schneider and Esch3 based upon hypothetical dissociation pressures of Cu20 and (a; 2S dissolved in copper illustrate the type of reasoning that has been used to account for the discrepancy. In the discussion of the previous paper, the authors pointed out that the discrepancy might possibly be due to impurities in the copper, although the purest form available was used. Further consideration of the problem suggested that the impurities likely to have the greatest effect on the solubility of SO2 in copper were oxygen, sulphur and carbon. Accordingly, further experiments have been made to show the effects of these elements. EXPERIMENTAL METHODS The apparatus used for measuring solubility was essentially the same as that shown in the previous paper. However, since it was desired to make measurements at low pressures, a McLeod gauge was added and 6-mm. glass tubing was substituted for the capillary. This increased the "hot volume" considerably but was necessary in order to obtain good vacuums in a reasonable length of time. A mercury diffusion pump was also installed.

Jan 1, 1942

By Douglas R. Piteau, Dennis C. Martin

Instability of rock slopes may occur by failure along pre- existing structural discontinuities, by failure through intact material or by failure along a surface formed partly along discontinuities and partly through intact material. Although certain fundamental failure modes are recognized, the mechanisms of slope failure are varied and complex. Such mechanisms are governed by the engineering geology conditions of the rock mass, which are almost always unique to a particular site. An understanding of failure mechanisms requires a knowledge of the physical, mechanical and strength properties of the intact material and discontinuities which make up the rock mass, as well as the structural geology and hydrogeology. These engineering geology parameters also must be evaluated with respect to the slope geometry to determine failures which are kinematically possible. Only after obtaining a reasonable appreciation of the possible failure modes can a rational mechanical stability analysis be carried out. Both two-dimensional and three-dimensional failure mechanisms should be considered in assessing the design of rock slopes. Simple analyses methods are used initially to identify those possible failures which could control slope stability. More complex and detailed analyses usually are required for a few critical failure modes which could control stability, or where a more complex type of failure mechanism is envisaged. Complex failure mechanisms are usually identified when assessing previous slope failures. More detailed information concerning slope geometry and engineering geology parameters must be acquired where analyses must be more rigorous.

Jan 1, 1983

By Nicholas J. Grant, Robert F. Wilde

TAYLOR and Floyd's"" work in establishing phase diagrams based on the elements Ni-Cr-Ti-A1 has led to an understanding of the precipitation hardening mechanism in alloys based on these elements. Nordheim and Grant4 concluded that in simple alloys, and where the aluminum to titanium atomic ratio was such that less than three out of five aluminum atoms were replaced by titanium, the precipitate on aging is the face-centered-cubic Ni 3A 1 phase, called They further found that increasing amounts of hexagonal ? phase, Ni3Ti, precipitated from these alloys when the titanium content exceeded the solid solubility of both matrix and Ni3A1. For alloys of Ni-Cr-Ti-Al, in which the titanium and aluminum contents each ranged from 0 to 4 wt pct, the titanium-rich was superior for strengthening to either pure ?' or 7. It was also noted that the combined titanium plus aluminum content (atomic pct) was a direct measure of the high temperature strength and overaging temperatures for these alloys.4 The present investigation was undertaken to extend existing data on precipitation hardening in the more complex commercial alloys containing higher titanium plus aluminum, and with significant quantities of cobalt, molybdenum, and carbon. Experimental Procedure Reforging of As-Received Bar Stock—The alloys were received as ground, forged bar stock. Chemical analyses and the as-received bar diameters are shown in Table I along with the ASTM grain size after the various treatments. All stock except the Waspaloy was reforged to % in. diam to gain material and to facilitate machining of stress-rupture specimens. Forging was carried out at 2100°F, and discontinued when the bar temperature fell to 1800°F. Heat Treatments—For experixental simplicity it was desirable to heat treat all of the alloys at, the

Jan 1, 1958

By AIME AIME

PERHAPS the most interesting paper of the subsidence session on Monday morning was that by Roland D. Parks entitled "Yieldable Metal Props for Underground Support." This paper described the development of a telescoping prop made from two pieces of pipe. The lower and larger in diameter has cast in it a soft metallic alloy which is slowly extruded through an orifice in the upper and smaller piece of pipe. In this way, the length of the prop decreases gradually as the load from the roof increases. The stress-strain diagram for these props, as tested in the laboratory, is almost ideal, and can be duplicated satisfactorily in successive tests. They have not yet been tested underground. Another paper of much interest was presented by Prof. P. B. Bucky. It is an addition to his series on structural models as applied to mining and was entitled "Effect of Approximately Vertical Cracks in the Behavior of Hori¬zontally Lying Roof Strata." It was illustrated by motion pictures of a model under test. After explaining the un¬derlying theory, the apparatus and the mode of testing, Prof. Bucky set forth the effect of vertical cracks in a mine roof, as follows: (a) the wider the crack, the weaker the roof; (b) where the sides of the crack are in juxtaposition, there is little weakening of the roof; (c) grouting cracks whose sides are not in contact restores the strength of the roof until it may be as strong as, or stronger than the uncracked roof. Small paper props helped sustain the roof. Both the nature of the material and its bonding affect its behavior under stress.

Jan 1, 1933

By David Cornell, D. L. Katz

Procedures for computing turbulent flow of gas in steady state near the well bore and a graphical method for predicting unsteady state laminar flow at distances from the well have been combined to compute pressure gradients in gas reservoirs. Methods are discussed for predicting single and multiple transients at constant flow rate in an infinite reservoir, predicting constant How rate. in a finite reservoir, reproducing and interpreting back pressure test data, and prediction of the behavior of a closed-in gas well. An example of the graphical method is given for a single transient and the results are compared to a published analytical solution. A typical calculation of the pressure gradient in a reservoir and the production of gas is made .starting with data from a hack pressure test. INTRODUCTION The calculation of pressure gradients throughouse a ga-reservoir at any point in its production history is a complex problem involving turbulent flow near the well bore and unsteady state flow of the gas from the reservoir. The problem is complicated further by the variety of boundary conditions that may be imposed upon the flow. Such boundary conditions include finite or infinite reservoirs. constant or variable rates of production, constant or varying bottom hole pressures, complex initial pressure distributions throughout the reservoir, and pressure maintenance through cycling. In addition to these problems there are the practical difficulties associated with natural gas reservoir analysis These might include: (1) variation. in the permeability and porosity throughout the formation. (2) variations in the thickness of the formation, (3) communication of the producing formation with other producing zones. (4) radial variations in permeability due to influx of drilling fluid. acidizing. or the buildup of liquid in the formation around the well, (5) partial penetration of the producing zone. (6) water flood, and many others. These problems will be considered eventually. In the mean- time, it is necessary to present methods of handling the case of radial flow through a homogeneous, regular, producing stratum to a single well uncomplicated by other factors. The idealized case of steady state, radial flow from a natural gas reservoir was studied by Elenbaas and Katz5 and by Mac-Koberts.' An analysis of the unsteady flow of gases through porous media has been made by Aronofsky and Jenkins' for the one dimensional laminar case with the boundary conditions of constant downstream pressure and uniform initial pressure. Solutions for the partial differential equation for unsteady state radial flow of liquids through porous media have been given by Van Everdingen and Hurst" for the constant bottom hole pressure and constant production rate cases for laminar flow in a reservoir initially at a constant pressure. The analogous heat transfer equation has been treated by Perry and Berggren9 for the case of quenching a cylindrical hole in an infinite medium to a constant temperature. The back pressure curve, which involves the variation of the bottom hole pressure as it is determined by the behavior of the reservoir as a whole. has been studied by Rawlins and Schellhardt,10 Binck-lev,' Baumel and Breitung,' and others. No complete. adequate treatment has been given for the unsteady state, radial flow of gases into a cylindrical hole from a porous medium with or without the presence of turbulent flow and for any set of boundary conditions. If one relies only on analytical solutions of the basic equations, a new solution must be obtained for each new boundary condition. Furthermore, the complexity of the mathematical expressions for boundary conditions other than the very simple cases limits the use of analytical solutions. Graphical methods exist, however. that are general in nature, accurate, and readily employed. The analysis of steady and unsteady, laminar and turbulent, radial flow for various boundary conditions with application to specific natural gas well problems by means of graphical procedures forms the content of this paper. STEADY STATE RADIAL FLOW EQUATION FOR LAMINAR AND TURBULENT FLOW A steady state radial flow equation for laminar and turbulent flow through unconsolidated sands has been given by Muskat as discussion of the work by Elenbaas and Katz.5 This equation is based on the properties of unconsolidated

Jan 1, 1953

By K. K. Clark

Excessive injection pressures in water injection wells may create deeply penetrating fractures, or may open up existing reservoir fractures. If these fractures are oriented toward offset producing wells, oil recovery at injected water breakthrough and ultimate recovery will be impaired. A method of calculating fracture lengths from pressure fall-off test data is presented. The method is based on a linear flow model that simulates conditions present during the early-time period after shutting in an injection well. Fracture lengths can be calculated directly if formation permeability is known. A graphical technique is presented that provides fracture lengths based on permeabilities calculated from normal fall-off tests, where those permeabilities are adjusted for flow geometry. Test data from four injection wells and results obtained from applying the method to these wells are discussed. Introduction Rates of water injection into nonstimulated wells in low permeability reservoirs frequently fall below economically desirable levels. Therefore, some form of stimulation such as hydraulic fracturing often is performed on these wells. Usually these fractures penetrate a short distance from the well — short as compared with interwell spacing — and therefore should not create problems of water channeling to offset producing wells. In the past, some operators have been tempted to increase injection pressures continually to maintain a specified injection rate. But pressures cannot be increased indefinitely. Field data indicate that continued injection above fracture opening pressure can cause excessively long fractures to approach between well distances. If these long fractures intersect or closely approach offset producing wells, premature water breakthrough can result. It is difficult to seal effectively these fractures by various workover procedures after premature water breakthrough has occurred. This paper describes testing procedures that are potentially capable of detecting premature water breakthrough before it occurs. Knowledge of fracture lengths and fracture opening pressures can assist field engineers in selecting optimum operating conditions for water injection wells. Fracture lengths should be calculated from pressure fall-off tests on injection wells, and maximum permissible iniection pressures should be determined from step-rate injectivity tests. Equipped with this information, the field engineer is in a better position to recommend for a particular injection well the optimum operating conditions that will lessen the chances of channeling to offset producers. Historically, pressure transient tests have been conducted primarily on producing wells and analysis procedures have been based on radial flow concepts. Several authors have suggested that these same procedures be applied to tests conducted on water injection wells. This application is justified for wells that are not connected to extensive fracture systems. However, if the formation is severely fractured, the interpretation methods must be modified. Several authors have presented the pressure response of various systems that are intended to simulate reservoir conditions. A paper by Russell and Truitt* on vertically fractured svstems is probablv the most useful from the standpoint bf the fieid engineer. Russell and Truitt presented the pressure-vs-time behavior of a well connected to vertical fractures with various fixed lengths. Their permeability adjustment technique is used in this paper to refine methods of calculating fracture length and interwell permeability. Theory and Definitions Three flow-system geometries are considered in analyzing injection well test data. These various geometries are applicable during specific time intervals of transient pressure tests. Schematic drawings of the flow models, and the time intervals over which they are applicable, are shown in Fig. 1 in the chronological order that they are applied to the pressure response of water injection wells in fractured formations. The very early response is simulated by an infinite linear system as shown in Fig. 1A. This representation permits the calculation of matrix surface area exposed to the fracture. The model shown in Fig. 1B is identical with the one studied by Russell and Truitt. They evaluated the transient pressure response of this vertically fractured system by finite difference techniques. The results were presented as tabulations of dimensionless pressure drop functions for a range of fracture lengths. A semilog plot of these data shows that the apparent matrix permeability can be related to the true matrix permeability by a simple exponential function. Their adjustment factor is used in this paper to improve the accuracy of matrix-permeability and fracture-length calculations.

Jan 1, 1969

By Cloyd M. Smith

B. F. TiLLson*— The manifold difficulties of accurate anemometry in irregular sections of mine passageways, the irregular distributions of velocities in cross sections of the same, and the disturbing influence of the observer upon the air flow, all indicate an undesirable inaccuracy of results obtainable by any standardized method of traversing the section by an anemometer. It seems obvious that another, and simpler, method should be used to determine the volume of air flow in mine passages, namely: 1. At appropriate locations cement or calked framework rings should be installed permanently to equalize the irregularities of sectional contour and provide a place and means of attachment for a temporary cloth brattice which bears a rigid orifice. 2. The measurement of the velocity of air flow through the orifice may then be by anemometer or, preferably, by Pitot tube measurements of the differential pressures on both sides of the orifice in accordance with the standard practices available in engineering 1iterature. † The constants may be determined for various measuring positions in relation to the resulting "vena contracta." 3. The position of the person who makes the measurements is behind the brattice out of the air stream. The Pitot tube does not offer as disturbing an obstruction as the anemometer. A recording gauge may be employed to integrate fluctuations in air flow through that portion of the mine. No traverses are required because the reading may be at a single central point. An anemometer can be used with an orifice flow. The orifice will increase the air velocity at the measuring point, with correspondingly more accurate measurements where the normal air velocity through the passageway is low. Portable brattices might be devised with the cushioning rims which would seal against irregular rock surfaces where permanent rings were not available or feasible. The development by the Ventilation Committee of standard procedures and devices for the orifice measurement of the flow of mine ventilating air might be a desirable project for this coming year. C. M. Smith (author's reply)—Thank you for your discussion of my paper on underground anemometry. Your suggested method of measuring underground air flow is a novel one which might be applicable in some situations. It should be tested along with other suggested methods in any investigation of this subject. G. E. McElroy*—In spite of the adverse publicity that vane-anemometer methods of air measurement have had in the past and that contributed by the present paper, I endorse Mr. Erickovic's statement that anemometer traversing "has proved to be widely applicable, expeditious and simple" and add that available methods are accurate enough for the purposes for which they may be used. The fact that the great majority of minor mine officials assess relative changes in rates of air flow by comparison of crude vane-anemometer measurements, known to average 20 to 30 pct high, has no important bearing on this subject, because state inspection standards were based originally on such methods of air measurement. Federal inspection standards are based on actual rates of flow as determined by traversing, and interest in traversing methods is rapidly increasing. In considering traversing methods, three aspects are of major importance: (1) the absolute accuracy of calibrations; (2) the degree of interference with normal flow conditions introduced by traversing methods designed for accurate measurement by shaft-mounted instruments; and (3) the proper "method" factor to use for approximate measurements by hand-held instruments. With respect to absolute accuracy of calibrations, we have always placed reliance on calibrations made by the National Bureau of Standards, with which manufacturers' calibrations have usually agreed very closely. It is therefore particularly disturbing to find7 that calibrations made previous to June 1947 are presumably about 5 pct in error because of excessive registry caused by the thin flat plates on which anemometers were mounted for calibration. Velocities corrected for calibration have therefore averaged about 5 pct low in all probability. In this connection, it is interesting to note that an anemometer calibrated against Pitot-tube measurement by a single-point method in the Bureau of Mines experimental coal nine in 1923 indicated this same difference of about 5 pct and that the same instrument calibrated by a traversing method in a metal mine some months later indicated a difference in the same direction of about 4 pct. These results are reported by the Bureau of Mines.8 Regarding the degree of interference, or changes in velocity distribution, caused by the position of the observer's body in traversing operations, misconceptions seem to be especially prevalent, resulting in increasing advocacy of methods, such as the "clear section" method outlined in this paper, that cause just the type of interferences that they are designed to avoid. The degree of interference for any method may be gauged easily by a few experiments with a velocity-pressure gauge connected to a Pitot tube or with an indicating velocity meter such as the Velometer. In an experiment cited by McElroy and Richardson,# a decrease of 5 pct was noted at ten widths upstream from a 6-in. plank, whereas an observer's body at about the maximum practical distance of 6 ft downstream from the instrument is only about four widths away. In the Bureau of Standards paper previously mentioned, it is recommended that supports used in calibrations be at least 16 widths downstream. In practice, therefore, a downstream position of the observer is ruled out as far as accurate measurement is concerned. Operation of the anemometer by rigid shaft support from a point outside the section is seldom practicable; however, accurate results can be obtained, with the anemometer rigidly attached to a short shaft and held at arm's length, by an observer advancing across the traversed section while he faces the opposite wall and stands sideways to the current, provided that he keeps the instrument at least 3 ft away from his body at all times and traverses the entire section with it. If the traverse can be started with the observer in a side recess, the entire section can be covered in one operation. Normally, it would be covered in two half-sections. The presence of the observer's body does not, as is commonly supposed, increase the average velocity throughout the remaining part of the section. Rather, the velocities 1 to 2 ft on either side of his body are increased, but the distribution of velocities throughout the rest of the cross section remains normal, and a traverse made as stated gives a true average velocity for normal-flow conditions. Regarding the proper "method" factor for accounting for interference in the approximate methods of traversing with hand-held instruments, here again confusion prevails, for which the writer must assume some of the blame. Comparison of consecutive traverses made by shaft-held and hand-held 4-in. anemometers in field work after the tests reported by McElroy and Richardson' gave method factors

Jan 1, 1950

By Georges Caraghiaur

INTRODUCTION A small, independent mining enterprise (SIME) is an independently owned and operated business concern engaged primarily in mineral development, from the exploration to the production stage. By definition, a SIME is not dominant in its field and has no long-term financial backing. It is not a major producer of minerals, nor is it a petroleum company, a government organization or a subsidiary of such organizations. A SIME may or may not be listed on stock exchanges. The SIME is also called small miner, junior mining company, speculative mining company, and penny-stock mining company. The survival and growth of a SIME is most often controlled by an independently minded entrepreneur, who not only conceives and carries out new projects, but is materially affected by the success or failure of these projects. Usually, a SIME does not have a large or constant cash flow. Such a lack of long-term financial backing forces the SIME to meet the challenge of finding capital for its activities on a step-by-step basis. Its survival strategy is thus based on finding funds at the right time, of the right type and in the right quantities. The purpose of this paper is to show that the type of venture in which a SIME is involved affects the difficulty of raising new capital and the choice of possible sources of funds. The Small, Independent Mining Enterprise (SIME) The SIME is not a figment of the imagination of financial speculators. In Canada, there are more than 1,800 small mineral enterprises which spend on the average less than $1,000,000 per year on activity which is directed at bringing forth new mineral supply. In the United States, 64% of the non-fuel mining operations are conducted by nine or fewer men, and the coal industry is characterized by several thousand smaller independent producers, still predominantly family owned or controlled. In Chile, 80% of the mines can be classified as small mines. In the Philippines, approximately 60% of metal mining operations are classified as small mines. The SIME is actively engaged in mining all over the world, and very much so in the Pacific Rim. The Mineral Supply Process The whole process of bringing forth new mineral supply involves a dynamic sequence of activities, ranging from the initial exploration for a mineral occurrence to the production of a marketable product. A typical sequence is outlined in Figure 1. At the grass-roots exploration stage, a series of geological, geophysical and geochemical tests is aimed at locating a mineral occurrence. Especially in the early phases of such activities, the uncertainty (risk) surrounding a venture is high, since only general geological information exists on which to base a judgement of the economic viability of the venture. Such risk is attractive to few investors. As the information-gathering process continues, uncertainty diminishes. Once exploration efforts result in the discovery of a mineral occurrence, i.e. when indications of mineralization and mineable widths are obtained by drilling, there is still uncertainty concerning the extent of mineralization and the probability of having located an economic mineral deposit. The expected return on investment at such a stage may well be negative but the slight possibility of a very high positive return will make a number of financial sources available to an exploration company. At the development stage, much of the uncertainty

Jan 1, 1985

By Walter Crafts, John L. Lamont

An investigation has been made of the multiplying factors for some of the more common alloying and deoxidizing elements for use in calculating hardenability of steel according to Grossmann's method. The factors for manganese, silicon, and aluminum that were reported in an earlier communication2 have been confirmed by microscopic determination of the half-martensite structure rather than on the basis of an empirically determined hardness corresponding to a half-martensite structure. Measurement of ideal critical diameter by microscopic examination was found to be necessary for other alloying elements, and multiplying factors for nickel, chromium, molybdenum, zirconium, vanadium, titanium, and boron have been determined. The nature and order of magnitude of the multiplying factors reflect the effect of the alloying elements on the structural character of the steel. Except for nickel and vanadium, the multiplying factors agree fairly well with previously published results. Good correlation between actual and calculated ideal critical diameters has been found in developing the multiplying factors and in checking the results against fairly simple steels. However, some discrepancies have suggested the need for a more thorough study of low-carbon and complex steels. Testing Procedure The investigation was conducted principally on steels made at the Union Car- bide and Carbon Research Laboratories, Inc., in high-frequency induction furnaces using Armco iron and standard alloying materials. However, a few open-hearth steels were used in establishing the effect of nickel, and the hardenability factor for boron was based primarily on open-hearth steels. All bars were normalized prior to the machining of Jominy hardenability specimens. The Jominy test was carried out under conditions standard for the test.3 Austenitizing temperatures judged to be appropriate for the compositions of the steels were used. Chemical analysis was determined on a sample taken adjacent to the Jominy specimen. Residual amounts of phosphorus, sulphur, nickel, chromium, molybdenum, and copper were determined on only one heat of each group made with the same materials during the same period. "Acid-soluble" aluminum and zirconium rather than total amounts were determined, as it is considered probable that the acid-soluble amount is more representative of the effective alloy. As tin was present to the extent of only 0.002 per cent, its effect was neglected. The method used to determine boron in the steels shown in Table 9* was developed by Galen Porter, Vincent Napoleon, and Thomas R. Cunningham, of the Union Carbide and Carbon Research Laboratories, Inc., and is a modification of J. Naftel's procedure for boron in soils

Jan 1, 1944

By John L. Lamont, Walter Crafts

An investigation has been made of the multiplying factors for some of the more common alloying and deoxidizing elements for use in calculating hardenability of steel according to Grossmann's method. The factors for manganese, silicon, and aluminum that were reported in an earlier communication2 have been confirmed by microscopic determination of the half-martensite structure rather than on the basis of an empirically determined hardness corresponding to a half-martensite structure. Measurement of ideal critical diameter by microscopic examination was found to be necessary for other alloying elements, and multiplying factors for nickel, chromium, molybdenum, zirconium, vanadium, titanium, and boron have been determined. The nature and order of magnitude of the multiplying factors reflect the effect of the alloying elements on the structural character of the steel. Except for nickel and vanadium, the multiplying factors agree fairly well with previously published results. Good correlation between actual and calculated ideal critical diameters has been found in developing the multiplying factors and in checking the results against fairly simple steels. However, some discrepancies have suggested the need for a more thorough study of low-carbon and complex steels. Testing Procedure The investigation was conducted principally on steels made at the Union Car- bide and Carbon Research Laboratories, Inc., in high-frequency induction furnaces using Armco iron and standard alloying materials. However, a few open-hearth steels were used in establishing the effect of nickel, and the hardenability factor for boron was based primarily on open-hearth steels. All bars were normalized prior to the machining of Jominy hardenability specimens. The Jominy test was carried out under conditions standard for the test.3 Austenitizing temperatures judged to be appropriate for the compositions of the steels were used. Chemical analysis was determined on a sample taken adjacent to the Jominy specimen. Residual amounts of phosphorus, sulphur, nickel, chromium, molybdenum, and copper were determined on only one heat of each group made with the same materials during the same period. "Acid-soluble" aluminum and zirconium rather than total amounts were determined, as it is considered probable that the acid-soluble amount is more representative of the effective alloy. As tin was present to the extent of only 0.002 per cent, its effect was neglected. The method used to determine boron in the steels shown in Table 9* was developed by Galen Porter, Vincent Napoleon, and Thomas R. Cunningham, of the Union Carbide and Carbon Research Laboratories, Inc., and is a modification of J. Naftel's procedure for boron in soils

Jan 1, 1944

By AIME AIME

TWO technical sessions, an excursion through the Midwest refinery and a smoker, marked the first day of the meeting of the Petroleum Division at Casper, Wyo., on Aug. 28. Ninety-nine members and guests registered and there was an excellent attendance at 'all functions. The -local committee under the general chairmanship of J. C. Lindsay, general manager of the Western Pipe Line Co., had made every possible arrangement for the convenience and comfort of the visiting members and the Program Committee under E. L. Estabrook, vice-chairman of the Petroleum Division, had brought together a most interesting series of technical, papers. The meeting centered mainly on the various features of the Salt Creek field but there were also contributions from the technology of production in California, the Mid-Continent, and the Texas fields. The opening session was called to order by Mr. Estabrook at the Townsend Hotel on Friday morning. The members and visitors were welcomed appropriately by Ex-Governor B. B. Brooks, president of the "Rocky Mountain Oil and Gas Association, who recalled the changes that had taken place as Casper, a frontier cow town, became a thriving oil metropolis. F. Julius Fobs, chairman 'of the Petroleum Division, responded and then took the chair. He introduced H. Foster Bain, Secretary of the Institute, who expressed the regret of those members members who found it impossible to stop over en route to Salt Lake City and his own pleasure at meeting with the Division in the field. Following these introductory ceremonies the technical session began with a "Sketch of the Geological Formations of Central Wyoming," presented by J. G. Bartram of the Midwest staff. It was brief and to the point and contributed greatly to the easy under¬standing of the succeeding papers by those unfamiliar with the region. The talk was illustrated by a large scale columnar section -and a copy of the excellent, geological map of the State recently issued by the U. S. Geological Survey.

Jan 1, 1925

By Carl Lee

OXYGEN-FREE high-conductivity copper (OFHC brand) that is now being commercially offered for the first time represents a notable achievement in electro-metallurgy and is the outcome of endeavors that have extended over a long period. Its manufacture is novel in that electrolytically refined copper is melted in electric furnaces and cast into vertical water-cooled molds. The ingots show the "pipe" characteristic of sound gas-free metal and microscopic examination even at high magnification reveals no cuprous oxide in the copper. Owing to the patent situation, the United States Metals Refining Co., the producers, cannot at this time divulge the details of manufacture, but the operations are under precise control so that the castings are of great uniformity and the copper contains no residual deoxidant. Figs. 1 and 2 show photographs of cross-sections of a wirebar and a billet, both vertically cast.

Jan 1, 1933

By C. H. Mahoney, P. E. LeGrand, A. L. Tarr

MAGNESIUM, it is now generally realized, differs in some important aspects from most other structural metals, not excepting even its close neighbors, the aluminum-base alloys. This is particularly true with respect to the effects of elevated temperatures on the two light metals when in the molten state. Aluminum, on the one hand, should not be raised above its melting point any higher than is absolutely necessary if one is to avoid danger of gas absorption and a tendency toward grain growth in the resultant casting.1 Magnesium alloys, in sharp contrast, actually benefit by being heated to temperatures considerably above their melting point. It is a commonly accepted practice to establish the desired fine grain in the industrial magnesium alloys of the aluminum-bearing group by raising the temperature of the melt after the refining treatment to some 25e C (482°F.) above the melting range. To recall briefly the typical practice for magnesium alloys, the molten metal is refined by fluxing at about 730° C. (1350 F.), and after the melt has been covered with a suitable flux, the temperature is raised to between 870°C. (1600°F.) and 930°C. (I700°F.). It is then cooled as quickly as possible to the casting temperature. This superheating, as it is called, results in a fine-grained cast metal structure which has superior mechanical properties, enhanced amenability to solution heat-treatment, and better machinability than cast metal that has not been superheated. The minimum temperature of superheating varies to some extent with the composition of the alloys to be treated and usually increases with the percentage of magnesium in alloys containing the same constituent metals.2 It should be noted that the grain-refining effect of superheating is markedly apparent only in connection with the alloys containing aluminum as an alloying constituent-the binary alloy containing r.5 per cent manganese, for example, is not refined in grain to any noticeable extent by a superheating effort. While the phenomenon of superheating is well known in the magnesium industry, the mechanism of the process has remained a mystery. During the superheating cycle something occurs that forces a fine grain upon the solidifying metal. The process has been controlled in an empirical manner, and occasionally, especially on large-scale melts, and for no apparent cause, no grain refinement is obtained from a superheating treatment. Only a few papers of importance have been published on the subject. Of these, one of the most helpful is the paper by Achenbach, Nipper and Piwowarski,3 which gives considerable data concerning the effect of superheating on various properties such as fluidity, shrinkage and hot crack formation, as well as grain size, and a discussion without any definite conclusions on the theoretical aspects of superheating. A short article by Murphy, Wells and

Jan 1, 1945

By R. I. Jaffee, R. M. Evans

IN recent years, the interest in liquid metals as heat-transfer media for power plants has been very great. The possibility of the development of nuclear power plants has increased this interest and served as the impetus behind much research on low melting metals and alloys for such purposes. The principal reasons for consideration of liquid metals as heat-transfer media lie in their high thermal conductivity and consequent high heat-transfer coefficients, stability at high temperatures, and the high ranges of temperature possible. The element gallium possesses some of the requisite properties for a heat-transfer liquid. It is a unique material, having a low melting point and a high boiling point. Pure gallium melts at 29.78oC, and suitable alloying will produce a metal which melts below room temperature. The boiling point is about 2000°C. As it is a liquid metal, the heat-transfer characteristics would be good. Gallium is not now readily available, due in part to a lack of uses for the metal. Nevertheless, it is not a rare element, and a sufficient supply of gallium exists to permit its consideration for this use. Since gallium has some promise as a heat-transfer liquid, owing to its unique properties, research on the subject was carried on at Battelle Memorial Institute at the request of the Bureau of Ships, U.S.N. The research had as its objectives the determination of the effect of alloying on the melting point of gallium, and the study of the corrosion of possible container materials. In this research, alloys were found which had significantly lower melting points than pure gallium, but none which simultaneously fulfilled other additional requirements, chiefly the corrosion problem. Neither was it found possible to reduce the melting point of certain otherwise suitable alloys appreciably by small additions of gallium or gallium alloys. The results gave little hope that gallium alloys can be developed which enhance the good properties and minimize the undesirable characteristics of elemental gallium. Thus, gallium now appears less promising than other metallic heat-transfer media. The experimental thermal-analysis techniques used in this work have been described.' Experimental Results As a first approximation, the development of low melting gallium alloys was based on alloying elements suitable for use in a nuclear power plant, which also lowered the melting point of gallium. Information from the literature, summarized in Table I, indicates that. tin, aluminum, and zinc are the only suitable elements which cause a lowering of the melting point of gallium. Indium and silver also lower the melting point of gallium, but are of little interest for use in nuclear power plants. Of the elements reported not to lower the melting point of gallium, there is some ambiguity on the behavior of copper. Weibke3 obtained solidus arrest temperatures of 29°C for Cu-Ga alloys from 60 to 90 pct Ga, 0.8C lower than the generally accepted melting point. This may be the effect of a eutectic close to gallium, or, more likely, the result of impurities, or experimental error. The seven elements listed in Table I whose effects were not known were of potential interest if they lowered the melting point of gallium. Their effects were determined experimentally for this reason. Binary alloys containing nominally 2 pct of each of these elements were prepared in the form of 2-g melts by placing the components in a graphite crucible and holding them in an argon atmosphere at 370°C for 5 hr. These melts were then subjected to thermal analysis. In all cases. the solidus temperature was the melting point of gallium. Since these elements (As, Ca, Ce, Mg. Sb, Si, and T1) did not lower the melting point of gallium, they were not considered further as components of a eutectic-type alloy. Ga-Sn-Zn Alloys Preliminary considerations of this system for low-melting alloys were encouraging. All three binary systems were of the simple eutectic type. The composition and melting points of the eutectics were as follows: Sn-9 pct Zn (199°C), Ga-8 pct Sn (20°C), and Ga-5 pct Zn (25°C). Therefore, the probability of a ternary eutectic was high. For reasons to be discussed later, aluminum could not be used as an alloying constituent, leaving the Ga-Sn-Zn system as the only one of interest for low-melting gallium-

Jan 1, 1953

BUFFALO C E Moyer, Chairman (Buffalo, N Y I R M Jordan, Vice-Chairman H A Morlock, Secretary CHICAGO M E Nickel, Chairman (Chicago, Ill ) A M Kroner, Vice-Chairman W R McLain, Secretary-Treasurer

Jan 1, 1959

By M. Garfinkle

LITERATURE data1'3 have suggested that the resolved shear stress necessary to initiate slip in a particular slip system in tungsten single crystals is strongly dependent on the tensile orientation of the crystals. This orientation dependence is contrary to the critical resolved shear stress criterion. Because the Schmid factors for slip on particular {110}( I l l), {112}(Ill), or {123}(111) slip systems in a (100) oriented tungsten crystal are virtually identical to the respective Schmid factors for a (110) oriented crystal, slip should initiate on the same system in both orientations, independent of the values of the critical resolved shear stresses. Thus, it would be expected that, for a critical resolved shear stress model to hold, the proportional-limit stress for these two orientations must be similar. The expectation of similar proportional -limit stresses has not been borne out by reported experimental observations. Rose et nl.' reported that the proportional-limit stress for crystals near the (110) orientation was 92,000 psi, approximately three times that of (100) oriented crystals (31,000 psi). Garlick and probst2 reported greater than a fourfold difference. Most recently, Beardmore and ~ull~ examined tungsten crystals with orientations along the edge of the standard stereographic triangle and showed a gradual increase in proportional-limit stress from 28,000 psi for the (100) orientation to 93,000 psi for the (110) orientation. Again, the difference was more than threefold. As has been emphasized by these investigators, the apparent gross variation of proportional-limit stress with orientation precludes any meaningful analysis of slip mechanics using a simple critical resolved shear stress relation. The purpose of the present communication is to report that, by use of refined strain-measuring techniques, the proportional-limit stresses for the (100) and (110) orientations are quite similar. Obviously, to determine accurately the value of the proportional-limit stress, which is by definition the stress at which nonlinear stress-strain behavior first occurs, the method of measuring strain must be capable of high accuracy. The investigators cited used as the measured elongation the crosshead displacement of the tensile machine. This method, however, introduces extraneous strain contributions from the load train. Because these extraneous contributions are considerable in the initial portions of loading (as has been well-documented in the literature) the proportional-limit stress measurement, dependent on the deviation of a line from linearity, can be significantly affected. During the course of a recent study, room-temperature strain was measured directly on several (100)-and (110)-oriented tensile specimens axially oriented within 5 deg of the desired direction. Each specimen was fitted with two foil strain gages mounted on opposite sides of the 0.08-in.-diam reduced section. The tensile specimens were loaded at a crosshead speed of 0.01 in. per min on an Instron Universal Testing Machine. Strain was monitored through an external bridge circuit in which the specimen strain gages comprised two arms. The bridge output was recorded against the applied load. A strain of 2 x 10"" could be readily detected by this method. Some specimens were subjected to conventional loading while the load for others was cycled between zero and continually increasing values until the first deviation from linearity was observed. The results of these methods were similar, and the stress at which nonlinear behavior occurred was considered the proportional-limit stress. The proportional-limit stresses measured in this study are approximately 5000 and 6500 psi for the ( 100) - and ( 110) -oriented crystals, respectively, a range of values almost a magnitude less than those reported previously. Representative curves are presented in Fig. 1. Because of the nature of the measurements made, the point of departure of a line from linearity is often debatable. While the load-strain curve for the (100) -oriented crystals made a relatively abrupt deviation from linearity, the curve for the (110) -oriented crystal was more gradual, so that the actual point of tangency may be at a lower load than reported. Thus, the difference in values for the proportional-

Jan 1, 1967

[A Aamodt, H. C., A55 C Sales, Great Lakes Carbon Corp., 18 E. 48th St., New York, N.Y. Aamot, Olav Crone, M29 2126 M4, Galveston, Texas Aaronson, Hubert I., M47 E Prin Res Engr, Ford Motor Co., Met. Dept., Sci. Lab., Engrg. Staff, P. O. Box 2053, Dearborn, Mich. Aase, Glenn D., M54 D Prin Engr, Air Pollution Control Dist., 1480 Mission St., San Francisco 3, Calif. Abbett, W. A., Jr., M56 8629 Beverly St., Duluth 8, Minn. Abbey, Robert G., M56 138 Dartmouth Rd., Bala Cynwyd, Pa. Abbott, A. G., Jr., J52 E Test, Dev Engr, Chrysler Corp. Missile Div., P. O. Box 2628, Detroit 31, Mich. Abbott, Mark L., A58 Rep, General Refractories Co., 208 S. LaSalle St., Chicago, Ill. Abbott, W. K., J58 E Dev Met, Int'l Nickel Co., Inc., 67 Wall St., New York 5, N.Y.]

Jan 1, 1961

By John T. Norton, Matthew J. Donachie

Residual lattice strai?zs were produced in 2024 aluminum and ingot iron by uniaxial tensile deformation. These strains were rneasured on the original surface and ulith depth below the surface. The strains conformed approximately to those from a macroscopic stress distribution but they were not truly macroscopic in nature. The exact mechanism which apparently causes the coherently difi9,acting region of each grain to behave as if macroscopically stressed was not determined. MACROSCOPIC stresses in metals produce strains in the lattice which result in X-ray line broadening and line displacements. The latter effect can be utilized in a technique for determining stresses in metals as first shown by Lester and born.' Subsequent advances in technique have enabled the X-ray method of stress measurement to be satisfactorily applied to many problems involving residual stresses of a macroscopic nature, such as those due to welding, grinding, shot-peening, and so forth. In the case of stresses such as those described above, the correlation of X-ray- and mechanically determined data has been generally good. However, plastically extended polycrystalline metals have sometimes been reported2 to show line displacements upon release of the applied tensile load, yet the nature or origin of the residual lattice strains, rls, producing these displacements has never been clear. As will be pointed out, this lack of clarity regarding the macroscopic or microscopic nature and origin of these stresses casts doubt on the validity of results achieved by the commonly accepted techniques of X-ray stress measurement. This anomalous behavior requires clarification to remove the doubts concerning X-ray stress measurement. The present paper is the result of an investigation of the interesting behavior of such plastically extended polycrystalline metal bodies. The studies were originated to carry out the following tasks: 1) Observe whether a residual lattice strain is produced as a result of plastic extension and show whether any residual lattice strains produced can be related to the usual concept of a macrostress. 2) Examine the origin of any residual lattice strains observed. 3) Consider the implications or consequences of the existence of such residual lattice strains on the problem of X-ray stress measurement. THEORY 1) Lattice Strains. The theoretical developments necessary for the treatment of lattice strains and their relation to stresses follow from the classical theory of elasticity and have been adequately covered by arrett. For an isotropic solid under homogeneous deformation, it can be shown that, for uniaxial stresses where Dl is the macrostress acting in the longitudinal direction; E$L is the lattice strain in the plane defined by the surface normal and the longitudinal direction at an angle, , from the surface normal; ET is the similar strain in the transverse plane; E is Young's modulus; and v is Poisson's ratio. Eq. [2] is independent of angle + and Eq. [I] is a linear function of sin2, see Fig. 1, and can be solved analytically for DL if E and u are known and EL is measured. Thus, a uniaxial macrostress will be indicated by a linear E,L vs sinZ plot and a

Jan 1, 1962

By H. Rosenthal, A. L. Jamieson

THE action of mercury on stressed brass to produce cracks was known before Moore, Beckinsale and Mallinson1 showed that actual season cracking did not occur spontaneously but could be induced by ammonia. These investigators studied other substances, including diphenylamine, without finding that anything other than ammonia could cause season cracking. Grimston2 reported season cracking in cartridge cases stored in wooden boxes wetted with dilute sulphuric acid pickling solution. Season cracking associated with sulphur dioxide, water vapor and air has been reported by Johnston,3 although he reported that trimethylamine and pyridine did not cause cracking. Jevons4 has ascribed season cracking of brass in certain instances to trimethylamine, "aldehyde amine," "ketone amine" and pyridine, but no experimental work was done evidently to prove this definitely. Pyridine was investigated by Morris,' who found it to have considerable cracking power. In the present investigation, the object was a qualitative evaluation of a number of representative amines with respect to their ability to cause season cracking. Thus it was desired only that an appreciable vapor pressure of each amine be obtained in order to make the test as severe as possible, without attempting to test equivalent concentrations for comparative purposes. METHODS Specimens Two types of specimen were used: I. Unannealed 70-30 brass cups formed from 0.040-in. thick sheet. Height of cup was 1 3/8 in. and diameter was 1 7/8 inches. 2. First draw pieces of caliber .50 cartridge cases in the unannealed condition (70-30 brass). The cups were representative of a thin wall and thin base specimen, whereas the draw pieces have a thick base (1/4 in.) and a thick wall (approximately 3/32 in.). Both types of specimens contained high residual stress and cracked in less than one minute in a solution of I per cent mercurous nitrate and I per cent nitric acid provided that this was preceded by a 30-sec. pickle in 40 per cent nitric acid. Specimens were prepared as follows: (I) degreased in trichlorethylene, (2) rinsed in H20, (3) pickled 5 min. in 10 per cent by volume H2SO4 (1.84 sp. gr.), (4) rinsed in H2O, and (5) dried. Amines Tested In selecting the amines, representatives of the three series of amines and one series of substituted amines were chosen. The aliphatic series was represented by the methyl and ethyl primary, secondary and tertiary amines. These are the simplest aliphatic amines. For the aromatic series, the phenyl primary, secondary and tertiary amines were selected as being the simplest. The heterocyclic series was represented by pyridine, which is a simple heterocyclic base (tertiary amine).

Jan 1, 1944