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By C. R. Kuzell

STAFF: Editor, Gerhard Derge Carnegie lnstitute of Technology Schenley Pork Pittsburgh 13, Pa. Editorial Assistant, M. A. Redmerski Production Editor, Otto T. Johnson THE METALLURGICAL SOCIETY: C. C. Long, President; John Chipman, Past-President; J. S. Smart, Jr., Vice-President, T. D. Jones, Treasurer; R. W. Shearman, Secretary. PUBLICATIONS COMMiTTEE OF THE METALLURGICAL SOCIETY: D. J. Carney, Chairman; Robert Maddin, Past-Chairman; J. H. Hollomon, J. H. Jackson, H. H. Kellogg, T. B. King, F. C. Langen-berg, D. L. McBride, W. O. Philbrook, J. S. Smart, Jr., R. L. Smith, J. D. Sullivan, and F. L. Vogel Review and selection of manuscripts is under the supervision of the following Publications Committees: Extractive Metallurgy Division: H. H. Kellogg, Chairman; T. 8. King, Post-Chairmon; R. P. Hermsdorf, W. A. Krivsky, R. E. Lund, C. L. McCobe, Poul Queneou, A. 5. Russell, M. E. Wadsworth, and W. D. Wilkinson. Institute of Metals Division: R. L. Smith, Choirman; P. A. Beck, I. I. Bessen, J. O. Betterton, Jr., R. S. Davis, J. J. Gilmon, R. 8. Gordon, C. D. Graham, Jr., R. W. Guard, J. C. Gurlond, J. J. Heger, M. Hermon, J. N. Hobstetter, H. H. Johnson, Jr., I. R. Krarner, W. C. Leslie, R. A. Meussner, R. R. Nosh, G. E. Pellissier, T. N. Rhodin, A. U. Seybolt, L. L. Seigle, I. S. Servi, P. G. Shewmon, L. Slifkin, J. K. Stanley, C. D. Starr, and J. Washburn. Iron and Steel Division: F. C. Longenberg, Chairmon; H. L. Bishop, C. W. Sherman, J. 8. Wagstaff, and E. Whittenberger. Published bimonthly by the American lnstitute of Mining, Metallurgical, and Petroleum Engineers, Inc., 29 West 39th Street, New York 18, N. Y. Telephone: PEnnsylvania 6-9220. Subscription $20 per year for nan-AIME members in United States and North, South, and Central America; $25, foreign; $5 far AlME members. Single copies, $4.00, single copies foreign, $5.00. The AlME is not responsible for any statement mode or opinion expressed in its publications . . . Copyright 1960 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address, AlME New York ...Indexed in Engineering Index, Industrial Arts Index, and Chemical Abstracts ... Second class postage paid at New York, N. Y., and Ann Arbor, Mich. Volume 218, Number 4

Jan 1, 1961

By R. Kossowsky

BRIDGMAN has listed five possible transitions in bismuth at 25°C which were observed as volume changes. He was unable however to detect the last three transitions by electrical-resistivity changes. Kennedy and LaMori have verified the pressures at the Bi 1-11 and Bi 11-111 transitions. They suggested however that the 125-kbar transition previously reported by Bundy3 actually corresponds to the 90,000 kg per sq cm transition observed by Bridgman.1 Jura4 reported a well-defined drop in resistivity at 92 kbar obtained by a four-lead method. The Bi 111-IV and Bi IV-V transitions have not been reported in any of the above-mentioned references.'-' Bundy3 observed a small dent in the low-temperature boundary of the Bi Vll region which is consistent with the presence of a 111-IV boundary. Zeitlin and Bray-man5 were the only ones to report small but well-defined drops in resistance of bismuth at 44.0 and 63.8 kbar, corresponding to Bridgman's 111-IV and IV-V transitions, respectively. High-purity (99.99 pct) 0.020-in.-diam 0.5-in.-long bismuth wire was used to calibrate the Uniram tetra-hedral high-pressure apparatus used in the present work. The bismuth phase changes at 25°C were correlated with changes in electrical resistance as a function of pressure. The output of a sensitive bridge constructed of carbon resistors and kept at a constant temperature of ±°C during the measurements was fed to the Y axis of a MoseleyX-Y recorder and the X axis was used for time scans. Specimens were pressurized using a hydraulic press with maximum capacity of 200,000 lb. Load was applied in increments of 2000 lb and held for about 3 min. The resistance was recorded at the end of this time period. Good contact was established below 20,000 lb. Typical recorder charts are reproduced in Figs. 1 and 2 which show that resistance fluctuations were practically nil during each time scan. Well-defined discontinuities in resistance were observed at 58,000 and 82,000 lb, Fig. 1. Two small but definite "blips" are noticed at 92,000 and 122,000 lb, Fig. 2. At 156,000 lb another drop is observed which

Jan 1, 1967

By J. S. Dodge, I. M. Krieger

The laminarturbulent transition was studied for monodisperse rigid polymer latices as functions of particle diameter and concentration at several tube diameters. Breaks in the graph of friction factor US Reynolds number were used to characterize the transition; rates of shear were sufficiently high so that Newtonian behavior at the high shear limiting viscosity could be assumed. No abnormal behavior was noted at concentrations below 30 volume percent. At higher concentrations, suppression of turbulence was observed with critical Reynolds numbers rising to as high as 5,500 at 50 volume percent. No definite effect on the transition was noted due to variation of particle size or tube diameter. The type of surfactant used to stabilize the latex was found to have an important influence on the critical Reynolds number. INTRODUCTION For some polymer solutions and solid-in-liquid suspensions, the transition from laminar behavior to turbulence in pipeline flow has been reported to take place at unusually low1-5 and in some cases at higher than normal6,7 critical Reynolds numbers. Extreme values of critical Reynolds numbers (NRe*) have been found to range from 1 to 6,000, as opposed to the values of 2,000 to 3,500 which are obtained for ordinary liquids. Observations have also been reported of drag reduction in fully developed turbulent flow, i.e., a decreased value of the friction factor in the Reynolds number-friction factor plot6*10-14 in colloidal and polymeric fluids. In some cases, turbulence suppression (unusually large values of Nre*) was noted to occur preceding the drag reduction,6 while a normal transition was noted in other cases of drag reduction.14 To relate the occurrence of turbulence suppression and drag reduction to the molecular or particulate structure of the fluid, it is desirable to characterize the structural variables with some precision. For most colloidal dispersions and polymeric fluids, this is very difficult; particle sizes, shapes and stiffnesses may vary over wide ranges in the same sample. Recently, however, a colloidal fluid has become available which consists of rigid spherical particles of highly uniform diameter dispersed in a simple Newtonian liquid. These are monodisperse polymer latices, prepared by carefully controlled emulsion polymerization reactions. The purpose of this research was to study the transition to turbulence in these well-characterized colloidal fluids as a function of concentration, particle diameter and tube diameter. Typical flow curves of latices of high solids content are shown in Fig. 1. While these curves were obtained with monodisperse latices, the general shape of the curve is also typical of a polydisperse latex. It is observed that a shear-thinning region occurs for low to moderate rates of shear. At sufficiently high shearing rates a limiting Newtonian viscosity is reached. The viscosity µ diminishes with decreasing volume fraction 4 at all shear rates. For 4 less than 0.25, latices are Newtonian at all rates of shear.15 An increase in average particle size (at a given extends the Newtonian viscosity region to lower rates of shear. A third factor which influences the

By M. J. Sinnot, J. C. Shyne

Low-frequency mechanical damping measurements were made to investigate internal friction in Fe-A1 alloys. The atomic ordering of the Fe-A1 system strongly influenced the stress-induced ordering internal friction. Magnetoelastic damping was also encounteyed and was shown to be reduced by the application of a static stress. THIS paper describes some damping experiments made on alloys of Fe and Al. Stress-induced ordering internal friction was measured with samples containing from 9.8 to 31.3 at. pct Al. Aluminum is soluble in a-Fe to about 50 at. pct and forms at least two long-range ordered structures, Fe3Al and Feu.' Stress-induced ordering internal friction is known to occur in many substitutional solid solutions, but few measurements of this damping effect have been made with alloy systems that have pronounced ordering tendencies. LeClair and Lomer developed expressions relating the relaxation strength of the damping process to the degree of atomic ordering and predicted that stress-induced ordering internal friction would be zero with complete ordering.' This concept was confirmed experimentally by Lulay and Wert using the system cd-Mg It is also consistent with the weak stress-induced ordering peaks observed in P -brass by Artman and in 16 wt pct Al Fe-Al by bert.' It was expected, therefore that the ordering characteristics of the system Fe-Al would strongly influence the stress-induced ordering internal friction exhibited by the experimental alloys. SAMPLE PREPARATION The alloys used in this investigation were induction melted under vacuum using high-purity melting stock. The iron was electrolytically refined Plastiron 101 which contained 99.85 wt pct Fe. The aluminum was a special 99.95 pct pure grade supplied by Alcoa. The only other raw material was spectrographically pure graphite which was used in small quantities as a deoxidant. The amount of carbon used was slightly in excess of the amount required to completely deoxidize the melt; this resulted in residual carbon contents of 0.01 to 0.02 pct in the finished alloys. The vacuum cast 2 1/2-in. diam ingots were hot rolled to 5/8-in. diam round bars. Portions of these bars were hot swaged and hot drawn to 0.050-in. diam wire. Straight pieces of the hot drawn wire were slowly heated to a temperature of 1300°C in a He atmosphere. After holding for 4 hr, the samples were allowed to cool in the furnace. This annealing treatment resulted in grain growth in the samples, the final grain size being about the same as the wire diameter. The grain boundaries were oriented perpendicularly to the wire axis, giving a bamboo grain structure. The existence of a preferred orientation could not be detected in these coarse grained samples. If the samples had a fiber structure, this probably would have been the same in all samples because of similar processing, thus the influence of crystal orientation on the relaxation strength would have been similar in all samples. The aluminum contents of the alloys are listed in Table I. EQUIPMENT The principle of the torsion pendulum was used for the internal friction measuring device. The

Jan 1, 1961

By Norris Johnston, Carrol M. Beeson

For many years the permeability of reservoir sands has been measured by flowing air through a cleaned and dried core sample. This differs from the true reservoir permeability in one important respect: the rock particles in the reservoir are surrounded by interstitial water, not air, and their physical shape and condition of hydration are greatly dependent thereon. Permeability as defined must be measured with a single-phase fluid. Since no means exist for removing the oil and gas from a core sample by simply flowing water through it, the sample must be cleaned and then resatu-rated with water before testing. The present discussion attempts to show that after the cleaning process a considerably different permeability is determined with salt or fresh water than is obtained with air. The postulate is made that the salt-water permeability is probably closer to the true reservoir permeability than is the measurement with air. This is discussed in relation to both physically possible and economically feasible measuremerits. Data On more than 1200 core samples are given to show the nature of the effects observed, and a plea is made for others to consider water permeability measurements as a routine necessity, eventually replacing air permeability in regions where the differences are great. Introduction Permeability is defined1 as a "a measure of the capacity of a porous medium to transmit fluids, when there is no interaction between the solids and the fluid." Darcy's law of liquid flow in porous media states: kA?P QµL/A?L [I] where Q represents milliliters of liquid of viscosity p centipoises passed per second through a porous medium of permeability k darcys and cross-sectional area A sq. cm. under a pressure gradient ?P/L atmospheres per centimeter, the flow being understood to be laminar or viscous, not turbulent. This equation defines the darcy. For the case of radial flow in a uniform sand, such as usually exists in the neighborhood of a well in an oil or gas sand, Darcy's law becomes:2 Here h is the net sand thickness in feet, Pe and Pw are pressures at the drainage radius4 and well radius, and re and rw are these radii, respectively. The productivity index3 is defined as the barrels of liquid produced per day per pound per square inch mean pressure differential between ferences and well bore, and is thus: By further definition, the specific productivity index is: or in terms of practical units, and allowing for shrinkage:

Jan 1, 1945

By R. W. Gurry

WHEN a steel in the austenitic state, with all its carbon in solution, is maintained, at constant temperature, in contact with a gas that removes the carbon from the surface, vet without otherwise altering the composition of the steel, the change in weight of the specimen, after any period of exposure, is a direct measure of the amount of carbon it has then lost. The purpose of the present paper is to show how, by application of established mathematical reasoning based on the fundamental diffusion law and on certain postulates, this loss of weight yields a complete picture of the distribution of carbon throughout a specimen of regular shape after any period of exposure, with all the accuracy required in any practical occurrence of decarburization. Precisely the same is true for the gain in weight during the reverse process of carburization, or for the gradual gain or loss of any element, so long as the steel comprises only a single phase at temperature, provided always that the experimental conditions conform to the postulates. The change in carbon content from surface to center of the specimen is always continuous, when everything is in solution, even though under the microscope the decarburized zone (or carburized rim) may appear to be sharply defined. The experimental procedure is described and some typical results are presented, which are then interpreted by application of the diffusion law. EXPERIMENTAL PROCEDURE Initially an endeavor was made to follow the gain of weight during the process of carburization in a hydrogen-toluene atmosphere, but it was soon found that the specimen became coated with graphite, which could not be removed without some loss of metal; therefore it was decided to continue carburization until the steel was saturated throughout, to remove all graphite from the surface of the specimen, and then to follow the loss of weight during decarburization in a moist hydrogen atmosphere at the same temperature as that used for carburizing. The carburizing procedure has been described in an earlier paper;1 it suffices to state here that the carburization lasted about 140 hr. at 760°C. (1760°F.) and 44 hr. at 1110°C. (2030°F.), these periods being long enough-on the basis of the calculations presented later-to ensure that the specimen was about 9.99 per cent saturated at each temperature. The speci¬men was a cylinder about 3.8 cm. long and 0.475 cm. in diameter; the materials were carbonyl iron, a commercial low-metalloid iron, and a steel with 3.6 per cent nickel and the usual proportion of other elements. The fully [carburized] specimen, after cooling at the top of the furnace tube, was placed in a lathe and sandpapered to remove all graphite; then the diameter was measured with a micrometer caliper, and the initial weighing (corresponding to complete saturation) was made. By means of a

Jan 1, 1942

By D. R. Hay, E. Scala

Electrotransport has been superimposed on the rate-limiling- step in zone refining which is the impurity diffusion through the liquid at the solid/liquid interface. The efficiency of zone refining is increased and relative resistivity ratios (P300°k/P4 2°K) he increased by 50 pel in tungsten for a given number of posses using- the electrotransport field-aided method. The effiect of zotze refining in the presence of an electric field on the relative resistivity ratio is examined as a function of its intensity and polarity. THE effect of electrodiffusion on the effective distribution coefficient of zone refining has been discussed by Pfann and Wagner.' Control of the distribution coefficient in zone refining is of twofold interest. A distribution coefficient of unity can be increased or decreased, making possible the transfer of some previously inseparable solutes. The general efficiency of zone refining can also be increased. In the conventional zone-refining process impurities are removed by their retention in the molten zone and subsequent deposition at the end of the rod after a complete passage of the zone. In higher-melting-point systems a second mechanism may also operate, the volatilization of impurities from the molten zone. It has been suggested by schadler2 that, in refractory metals, vacuum distillation plays the predominant role in purification. In Koo's results,3 the resistivity ratio decreased beyond a zone-refined length of 6 in. from the starting end, indicating that some purification does in fact occur by true zone-refining action. Hay and scala4 showed that the degree of purity as measured by the relative resistivity ratio method depends on the square root of time in the molten zone (number of passes) and thus appears to be limited by diffusion in the boundary layer at the solidifying interface assuming good mixing in the body of the molten zone where a linear rate would prevail. The final concentration of impurities in electron-beam floating-zone purification depends very much on the operating conditions and results obtained by various investigators2,3,5 are difficult to correlate. The diameter of the starting material, operating vacuum, and rate of traverse are among the factors to be considered. There are, nevertheless, some general observations to be obtained from the literature. Lawley5 reviewed the literature up to 1962 and concluded that the major contaminants generally remaining in tungsten after electron-beam zone refining are molybdenum and carbon. Molybdenum due to its high melting point and distribution coefficient of nearly unity would be expected to be difficult to remove by either volatilization or zone refining. Carbon is not only a common contaminant in vacuum systems, but is also very difficult to remove by conventional vacuum melting. even with vacuums of 10-7 mm Hg. For each of those impurities removed by zone refining the equation of Pfann and Wagner may be applied: It relates the effective distribution coefficient k to a superimposed driving force which accelerates the solute away from the interface with a terminal velocity L" and to the more conventional zone-refining parameters; v = rate of traverse, t = thickness of the diffusion layer at the solidifying interface, D = diffusivity of the solute in the molten zone, and ko = equilibrium distribution coefficient of the impurity.

Jan 1, 1965

IT may perhaps seem to you that I have deviated from sequence by having entered into the narration of this arrangement of the bellows, but, although they are not furnaces or vessels for containing the melts, they are essential agents for bringing to port the bark of your labors. Returning to our regular pathway, and supposing that, besides making the moulds, you have melted and cast not only statues and bells but also guns, it is true that a certain procedure is required in order to finish them. For this you should have the moulds full, and they should have come out very well, for in truth reason does not allow that they turn out otherwise for one who uses precaution. [II2V] Then you have taken your casting from the pit and have freed it of clay. Since I have told you nothing beyond this, do not be dismayed if you see the castings so rough and in a form that scarcely shows what they really are, for I wish to open up part of the way into the great labor of finishing them so that it may seem to you that you have been somewhat helped by me. Therefore, when it is a gun, first see that the iron spindle that has been placed in the middle of the core is taken out. You can do this easily by striking the heel of the core, especially if the spindle had first been covered with ashes, hemp, or a little rope. Then saw off the feeding head above the mouth, using either a dun steel saw with tiny straight teeth that has been tempered with oil or some other fat, or a hay sickle whose edge is gently hit by a little hammer. Then have the clay that is attached to the curls or other bronze parts lifted away with a chisel. Then with a scouring brush and water uncover the emblems, coats of arms, borders, and cornices that you made as ornaments. Striking it with a hammer, push inwards every superfluous bit of bronze. Finally, having cleaned the bronze by washing, scraping, and cutting away every bit of clay, strike its surfaces gently with a large hammer and thus make it very smooth. Likewise finish the mouth and all its cornices as exactly and completely as possible with files and any other instrument that serves best. Then take a long, powerful tool that has some steel on the point, made like a chisel and somewhat bent, or with three points like the iron blade

Jan 1, 1942

By W. A. Backofen, R. L. Fleischer

AN effect of orientation on the creep behavior of aluminum at 4.2 OK has been observed. Stress relaxation was measured in a hard-type tensile device after stopping the drive. From the spring constant of the device the load-time record could be converted to strain as a function of time. The strain sensitivity was 2-10-=, and the usual creep time of 1 min normally allowed a stress drop of about 25 g per sq mm. Further details of the apparatus and sample preparation appear elsewhere.' It should be noted that neither stress nor strain were constant, so that quantitative comparison with current creep theories will not be made. Shear strain (y) as a function of time (t) was consistent with logarithmic behavior: y = A In t, where A is a constant. In some cases t was made as large as lo3 sec. In the results the quantity A divided by t (the resolved shear stress, which is the driving force for creep) is plotted as a function of strain prior to creep. The quantity A/t is thought to indicate qualitatively the ease with which dislocations can move during creep. In Fig. 1 are drawn tensile stress-strain curves and A/T-strain measurements for single crystals of three orientations: l(a) and l(b) for the maximum resolved shear-stress orientation, l(c) for an orientation 2 deg from [211], and l(d) for a [111] stress axis. The following observations were made: 1) At low strains the A/t values are nearly the same for the three orientations. 2) As strains increase, A/t drops most rapidly for [Ill.] and less rapidly for [211], while for the maximum shear-stress orientation it is constant during easy glide and drops abruptly at the termination of easy glide. 3) In stage 11, A/t values are again approximately the same for the three orientations. These observations are regarded as evidence that 1) the initiation of slip produces obstacles of essentially the same effectiveness for all of these orientations, while 2) the rate at which slip obstacles are produced before stage I1 is fully developed is strongly controlled by the amount of slip on more than one system. This second statement is consis-

Jan 1, 1961

By Jerry B. Newby

The outstanding features in Pennsylvania and New York during the past year were the buying of acreage for water-flooding in other Pennsylyania fields than the Bradford and Allegany districts, the wide adoption and use of the five-spot plan of development and water-flooding in the Bradford and Allegany districts, the discovery of gas production in the Onondaga lime in southwestern New York and the opening of the T. W. Phillips Gas & Oil Co. Fifth Sand pool in Butler County, Pennsylvania. Water-flooding has occurred in many other fields than the Bradford, Pa., and Allegany, N. Y., fields. In some the flood was a natural encroachment of edge water, in others the water was introduced into the productive sand through wells either accidentally or intentionally. Most of these floods have not been commercially successful. There has been some interest aroused in the Clarendon field, Warren County, Pennsylvania, by a new and apparently successful flood and other floods have been begun. Five-spotting in the Bradford and Allegany fields is the plan of water-flood development under which the area to be drilled is laid off in a grid of equal-sized squares with water intakes located at each corner of the squares and oil wells located in the centers of the squares. So far there are two five-spot water floods that are, beyond doubt,, commercial successes. There were 600 acres under five-spot flooding at the end of 1928, as against 150 at the end of 1927. By the end of 1929 there will be a total of between 1200 and 1500 acres five-spotted unless a low market for Pennsylvania grade crude oil develops. An increase of 6000 bbl. in average daily production is expected to accompany this development in 1929. The Belmont-Quadrangle Drilling Corpn. found the Onondaga lime or a higher strata at 3995 ft. north of Bolivar, Cattaraugus Country, N. Y., and a number of miles from any other important gas production. When drilled to 4006 ft. the well yielded 3,500,000 cu. ft. of gas and when shut in 1700 Ib. rock pressure. The one oil pool opened in 1928 was in Buffalo township, Butler County, Pa., in October, when the T. W. Phillips Gas & Oil Co. completed a wildcat well in the Fifth sand at 700 bbl. a day, which by the end of

Jan 1, 1929

By George Riter

OUR mineral-land laws need revising so as to provide definite title at the outset to the mineral deposits within any definite piece of land. The laws as they now stand, especially those applicable to lodes, breed uncertainty as to rights of possession prior to patent; and to my mind this is the worst feature of all, worse even than the apex bugbear. It is now almost impossible for anybody to tell with certainty what mineral rights exist within any area that is not covered y patent, or whether any valid rights exist at all. Our system is unique in permitting individuals to appropriate and exploit mineral lands of the public domain without notice of any kind to the Federal government, and to relinquish them without any ceremony at all. The result is a clouded record that cannot be cleared' up until each claimant is put to some sort of final proof. In order to accomplish this, new Federal legislation will be required. The requirements for a mineral survey and the proceedings for patent have always been cumbersome and expensive; and perhaps out of regard for the poor claim owner, who can ill afford the outlay for that sort of thing, the law does not require him to go through it unless he chooses to do so. Consequently, every active mining district has become encumbered with tangled groups of doubtful or conflicting locations, whose rights and boundaries, when any valuable ore is found, must usually be determined by lawsuits that are as expensive and as distressing as the stakes are high. So deeply has litigation entered into our mining system that a claim whose rights have never been disputed would probably be set down offhand, y a miner of the old school, as of no value. Think of the litigation over rights of possession on the Comstock lode-12 leading companies involved in an aggregate of 245 suits within a period of less than eight years! Ambiguous local records; the chance of erroneously placed or obliterated monuments; doubt as to the sufficient performance of the statutory annual labor; uncertainty as to prior conflicting or overlapping locations; anxiety as to the changing attitude of the Department of the Interior and the Forest Service-such considerations as these make an unpatented mining claim an unclean thing in the eyes of possible investors. Is it any wonder that they keep themselves and their money at a safe distance,

Jan 7, 1914

By Charles S. Barrett, Frederick N. Rhines, Robert F. Mehl

The solid solutions which aluminum forms with copper, and with magnesium and silicon, are not extensive, and accordingly could not be expected to form Widmanstatten figures profusely nor with great ease. A study of the Widmanstatten figures in these systems seemed desirable, however, because of the interest which these alloys bear towards age-hardening theories resulting from the necessary relationship between the age-hardening phenomena and the atomic processes leading to the formation of Widmanstatten figures.' Alloys of Aluminum with Copper The most accurate determination of the solid solubi1it.y of copper in aluminum seems to be that by Dix and Richardsoq2 whose results are represented in Fig. 1. According to this work, aluminum dissolves 5.6 weight per cent of copper at 548", and less than one per cent at room temperature. Judging from the constitutional diagram, this solid solu-lion on cooling tends to precipitate the compound CuA12, and this conclusion has been confirmed experimentally by Schmid and Wassermann.

Jan 1, 1932

By P. W. Bridgman

Flow and fracture are admittedly complicated phenomena of which we are yet only partially masters. There is not even nni-.persal agreement as to the details of the language best adapted merely to describe the phenomena, to say nothing of any theory. Certain points of view, however, are widely held, and there are certain general expectations as to what sort of procedures will prove permissible. A complete description of any situation involving fracture would demand a complete history of all the variables in the control of the experimenter. The experimenter endeavors so to choose his independent variables that they are adequate to determine completely the situation in the sense that when an experiment is repeated on the same initial material and with the independent variables running through the same sequence, all the other measurable properties of the system will also run through the same course. It is, I think, the universal conviction that when we are dealing with phenomena of flow and fracture, the most important of the necessary variables are the external forces acting on the various parts of the body; when the force history repeats, with certain obvious restrictions such as that temperature must be constant and non-mechanical forces, such as magnetic field, must be small enough to be ineffective, then the history of all measurable properties will repeat; in particular the alteration of geometrical shape due to flow will run through the same course, and when fracture comes, the character of the fracture will be reproduced. Complete mastery of merely the descriptive aspects of flow and fracture would demand the ability to predict the entire course of flow and complete characterization of the final fracture for every possible combination of forces, varying in time in all possible ways, when applied to bodies of all possible shapes. This full situation is obviously of prohibitive complexity. The first stage in reduction to manageable simplicity is to resolve the total situation into the sum of contributions made by small elements. Our thesis is that if each of the elements is adequately characterized, the behavior of the whole system is fixed. The element is usually taken of a simple geometrical shape, suggested by the mathematics best adapted to the particular situation. The forces acting across the faces of the elements are ultimately determined by the forces acting across the free faces of the whole system. The detailed process of finding the precise forces on the faces of all the elements in terms of the external forces involves the use of a special mathematical invention, the stress, a constructional quantity consisting of six components. The stress at any point in the body is determined by both the external force system and by the physical properties of the body at all points; quite different stresses prevail at the interior of bodies of the same shape under the same external forces in the elastic and plastic ranges. The forces on the faces of any element are, however, uniquely determined by the stress system at the element. Our fundamental thesis

Jan 1, 1945

By Paul D. Conatore

INTRODUCTION There are important reasons for a discussion of tungsten resources, reserves, and production in the Circum-Pacific area. First, the world's chief tungsten deposits, as well as most of the world's tungsten reserves and production, occur in this region. It is well known that the world's largest tungsten reserves are located in southeastern China and that for many years, the largest individual mine in the world was there. Although China still has the world's greatest tungsten production, the very high-grade scheelite mine of Canada Tungsten Mining Corporation in the Northwest Territories is the largest producer of tungsten today. There is certainly a great quantity of tungsten in Asia, but the strategic importance of this fact is now offset by the wide distribution of mines and production facilities throughout the world, especially in other parts of the Circum-Pacific area such as Australia, Canada, and the United States. In addition, much of the Circum-Pacific area is comprised of Mesozoic-Cenozoic orogenic belts. These global tectonic units are regarded as very favorable for additional tungsten deposits, particularly scheelite-bearing tactites, and consequently, prospecting and exploration will most likely be concentrated in the Circum-Pacific area. Second, tungsten must be regarded as one of the, most important metals of modern industry because of its very special properties. It has the highest melting point, the highest tensile strength at elevated temperatures, and the smallest compressibility of any metal. The metal also possesses a very high density, excellent corrosion resistance, good thermal and electrical conductivity, and a low coefficient of expansion. As a result, tungsten has found increasing importance in a wide range of industries. From the filament in an electric lamp, to cutting tools and drilling bits, to the exotic radiation shields that protect supersonic aircraft and spacecraft, tungsten plays an indispensable role in our daily lives. The primary objective of this paper is to present an overview of important facets of known and suspected tungsten in the Circum-Pacific area. Resources, reserves, current production, planned capacity expansions, and new operations, as well as an assessment of the probability for development of deposits in the Circum-Pacific area, are discussed. RESOURCES The average crustal abundance of tungsten has been estimated at 0.0015 kilograms per tonne. A comparison of the abundance of various metals in crustal rocks to that of tungsten is presented in Table 1, which shows that tungsten abundance is similar to that of its commonly associated metals, tin and molybdenum. Table 1. AVERAGE CRUSTAL ABUNDANCE OF VARIOUS METALS (Grams per Tonne) [ ] With careful thought, it can be realized that tungsten ore deposits result from the concentration of the metal, through normal geologic processes, to levels substantially greater than its average crustal abundance. The minimum technologically and economically workable tungsten concentration, or cutoff grade, is a function of (1) deposit tonnage, (2) mining and milling methods, (3) production tonnage, (4) capital and operating costs, (5) tungsten market conditions, and (6) value of associated recoverable metals. The tungsten cutoff grade that is currently exploitable at a profit varies from 0.09% W03 to 1.55% W03, reflecting concentration factors from 470 to 8200, as shown in Table 2. Table 2. CURRENT TUNGSTEN CUTOFF GRADES [ ]

Jan 1, 1982

By R. Floyd Farris

A method is presented for determining minimum waiting-on-cement time, which takes into account the differences that exist between types and brands of cements and such individual well conditions as depth, temperature, and pressure. The basis for the method was determined by laboratory tests. Being a laboratory development, several steps were required to prove its merit. The first step consisted of laboratory tests designed to determine the minimum cement strength required in wells. Basis was found for setting a minimum value of 8 Ib. per sq. in. tensile strength. Next, it was shown by laboratory tests that the time to 8 Ib. per sq. in. tensile strength may be expressed as a function of consistometer stirring time to loo "poises," the approximate relation being "the time to 8 Ib. per sq. in. tensile strength equals the time to I00 'poises' times three." Next, it was shown that the time of maximum temperature development in cement slurries, due to heat of hydration, is also related to consistometer stirring time to loo poises, but only by a factor of approximately two. It was shown also that the shut-in casing pressure will build up after cement is placed and register a maximum pressure at approximately the same time the slurry down the hole attains maximum temperature. From this and the relationships listed above, the general rule was established that minimum waiting-on-cement time (time to 8 Ib. per sq. in.) after casing cement jobs in any well is equal to the time when the shut-in casing pressure reaches a maximum, as measured from the initial mixing of cement, times a factor of 1.5. Cement plugs drilled in the field at the time prescribed by this formula were found to drill "firm to hard," thus confirming the laboratory tests. These tests prove that many of the present regulations for waiting on cement require a longer time than is absolutely necessary. Use of the method herein proposed offers the possibility of a saving of $1200 per well. Introduction The length of time allowed for cement to set after casing is determined either by state-wide rules, field rules, or self-imposed rules written into drilling contracts. In general, the time is dictated by experience and common practice. However, owing to differences in opinion and in experience of the various groups involved, waiting-on-cement time often varies from one area to the next. For example, an operator in an area where no rules exist may drill out of surface pipe at 24 to 36 hr., while another operator in another area may wait 48 hr. or more to comply with state or field rules, although the depth of the well, hole size, type of cement, and other data are identical. An even greater difference in practices will be found by making similar comparisons with respect to oil-string cement jobs. Differences in waiting-on-cement times of 36 to 48 hr. are common. Further complicating the picture is the rather common practice of allowing more waiting time for cement to set at the greater depths than is allowed at the shallow depths. This practice has existed for years in spite of the common knowl-edge1,2,3 that the temperature of the earth at the usual setting depths of surface

Jan 1, 1946

By G. W. P. Rengstorff, R. B. Fischer

A study was made of the effect of impurities on the bend ductility of cast molybdenum. High purity molybdenum was repared by re-melting under high vacuum. The ductility of "transverse-grain" specimens indicated that intergranular brittleness decreased with an increase in purity of the metal. THE production of as-cast molybdenum with high ductility at room temperature would make working of the metal easier and increase the usefulness of the as-cast metal. Furthermore, a .knowledge of the factors that influence the ductility of as-cast molybdenum might be applied to the problem of making fusion weldments having satisfactory room-temperature ductility. Individual grains of commercial as-cast molybdenum are slightly ductile at room temperature. However, the presence of carbides at the grain boundaries may cause the metal to fracture in a brittle manner. This behavior has been discussed.' The amount and distribution of the impurities in as-cast molybdenum would be expected, from previous research on the metal, to have considerable influence on its ductility. Some effects of oxygen and carbon on the mechanical behavior of the metal were discussed by Parke and Ham,2 Woodside,3 and Zappfe. Landgraf, and Worden.4 Parke and Ham2 found that, if a sufficient number of molybdenum oxide particles were present at the grain boundaries, the intergranular cohesion was reduced to the extent that arc-melted molybdenum would rupture intergranularly during hot forging. They also found that if the oxygen content was less than 0.003 pct, the cast molybdenum was hot forgeable. It is suspected, however, that forgeable molybdenum may contain a small amount of oxide that could reduce the ductility of the as-cast metal at room temperature. Also, there is the possibility of the unfavorable distribution of other impurities having a detrimental effect on the ductility of cast molybdenum. The results of a study of the influence of purity on the room-temperature ductility of cast molybdenum are presented here. Vacuum Arc-Melting to Produce High Purity Mo One way of determining the effect of impurities on the ductility of molybdenum is to prepare and test metal as free of all impurities as possible. Accordingly, the present investigation was undertaken with this in view. Arc melting in high vacuum (less than 0.1 micron of mercury) was chosen as the method for reducing the impurities below the concentrations occurring in commercial molybdenum. Commercial arc melting of molybdenum is carried out at about 50 microns pressure. During the arc melting, carbon and oxygen in the metal react to form carbon monoxide. By virtue of the vacuum process, the partial pressure of carbon monoxide is maintained at such a low value that the reaction greatly lowers oxygen and carbon contents. An excess of at least 0.03 pct C is used in commercial arc melting to insure that the oxygen content will be below 0.003 pct. The excess carbon remaining after the deoxidation step forms carbides on freezing. Some of the carbides precipitate at the grain boundaries and, as will be shown, have an unfavorable effect on the room-temperature ductility. In the present work, only the small amount of carbon (0.003 pct) contained in the commercial powder-metallurgy molybdenum used for melting stock was present. Partial removal of oxygen from the melt probably occurred as the result of the volatilization of molybdenum oxides, or by distillation of oxygen at the high melting tem-

Jan 1, 1953

By C. D. Hall

This paper may be divided into two main parts: (1) analysis and data to show that Eq. 6 adequately correlates the authors' experimental data, and (2) the assertion that Eq. 20 "should permit scale-up with data taken from one pipe diameter for Newtonian, inelastic non-Newtonian, and viscoelastic fluids, such as dilute polymer fracturing fluids, which produce considerable pressure reductions." The authors might well recommend that this broad grouping of fluid types could be correlated by using Eq. 6 (requiring data from at least two pipe diameters). On the other hand, Eq. 20 is only shown to be adequate for conditions within the range of the present data set. Specifically, predictions by Eq. 20 for diameter scale-up to casing sizes would give larger deviations than implied in Table 2, and scale-up for some other fluids that give large drag reduction could be grossly in error. The description of a class of fluids "which produce a diameter family of straight parallel lines on a log (d?p/4L) vs log (8 v/d) plot. . ." defines a necessary condition for using Eq. 6; i.e., that s shall be constant for each fluid. The proposal that Eq. 20 is applicable to turbulent flow of such fluids is equivalent to saying that the spacing of these parallel lines, with A being constant, will be found to correspond to m = -1.20 for all such fluids. Table 1 shows the values of m derived from data on 16 non-Newtonian fluids. The key statement of this paper is that the diameter exponents "do not vary significantly from . . . -1.20." In statistical terms, this says that the m value for each fluid, which was obtained from all the measurements made on that fluid. has not been shown to be different from the arithmetic mean of the m values for the 16 fluids tested. This implies that the group mean, -1.20, is a more reliable value to use for an individual fluid than is the m value derived from the data on that fluid alone. No statistical test is described to support the key statement that the diameter exponents do not vary significantly from -1.20. Such a test would have to take into account that each individual m value is shown to correlate the pressure gradients for its fluid, with only about 3 percent standard deviation over the diameter range covered. That is, the m value is not the result of a single independent measurement. Thus, it would not be sufficient, or valid, to compare the deviation of one of the m values with the variance of the 16 values of m about their mean. An alternative interpretation of the key statement is that the diameter exponents do not vary appreciably from -1.20; i.e., that using -1.20 does not cause serious inaccuracy. Table 2 seems to be offered in support of such an assertion. However, such a statistical treatment (1) is unnecessary and (2) cannot lead to any valid scale-up generalization. The amount of error introduced by using a 1"wrong" value of diameter exponent — i.e., -1.20 instead of m — is determined by Eq. 6. The ratio of the pressures predicted by Eqs. 6 and 20 for scale-up from ds in small pipe to d, in casing is The pressure for 30-percent calcium carbonate slurry (m = -1.112) in 10-in. ID pipe would be predicted 30 percent higher by Eq. 6 than by Eq. 20, if based on tests in 0.5-in. ID pipe. The data set tested in Table 2 represents only a limited sample of pipe diameters (ratio of about 4:l) out of the population of diameters that would

Jan 1, 1970

By R. Floyd Farris

A method is presented for determining minimum waiting-on-cement time, which takes into account the differences that exist between types and brands of cements and such individual well conditions as depth, temperature, and pressure. The basis for the method was determined by laboratory tests. Being a laboratory development, several steps were required to prove its merit. The first step consisted of laboratory tests designed to determine the minimum cement strength required in wells. Basis was found for setting a minimum value of 8 Ib. per sq. in. tensile strength. Next, it was shown by laboratory tests that the time to 8 Ib. per sq. in. tensile strength may be expressed as a function of consistometer stirring time to loo "poises," the approximate relation being "the time to 8 Ib. per sq. in. tensile strength equals the time to I00 'poises' times three." Next, it was shown that the time of maximum temperature development in cement slurries, due to heat of hydration, is also related to consistometer stirring time to loo poises, but only by a factor of approximately two. It was shown also that the shut-in casing pressure will build up after cement is placed and register a maximum pressure at approximately the same time the slurry down the hole attains maximum temperature. From this and the relationships listed above, the general rule was established that minimum waiting-on-cement time (time to 8 Ib. per sq. in.) after casing cement jobs in any well is equal to the time when the shut-in casing pressure reaches a maximum, as measured from the initial mixing of cement, times a factor of 1.5. Cement plugs drilled in the field at the time prescribed by this formula were found to drill "firm to hard," thus confirming the laboratory tests. These tests prove that many of the present regulations for waiting on cement require a longer time than is absolutely necessary. Use of the method herein proposed offers the possibility of a saving of $1200 per well. Introduction The length of time allowed for cement to set after casing is determined either by state-wide rules, field rules, or self-imposed rules written into drilling contracts. In general, the time is dictated by experience and common practice. However, owing to differences in opinion and in experience of the various groups involved, waiting-on-cement time often varies from one area to the next. For example, an operator in an area where no rules exist may drill out of surface pipe at 24 to 36 hr., while another operator in another area may wait 48 hr. or more to comply with state or field rules, although the depth of the well, hole size, type of cement, and other data are identical. An even greater difference in practices will be found by making similar comparisons with respect to oil-string cement jobs. Differences in waiting-on-cement times of 36 to 48 hr. are common. Further complicating the picture is the rather common practice of allowing more waiting time for cement to set at the greater depths than is allowed at the shallow depths. This practice has existed for years in spite of the common knowl-edge1,2,3 that the temperature of the earth at the usual setting depths of surface

Jan 1, 1946

By C. M. Wayman, J. F. Breedis

The crystallography of the martensitic transformation in the Fe-30 Ni alloy was reinvestigated. The scatter in the habit Plane as determined from measurements on the mid-rib plane was smaller than reported previously, and the orientation relationship was determined from a martensite plate having known direction cosines. From agreement with crystallographic theory and from observations of the morphnlogy of the martensite plates, it is suggested that the mid-rib plane represents the starting region of the transformation. THE crystallography of the martensitic transformation in the iron-nickel system has been the subject of many investigations.&apos;-7 However, for iron alloys containing approximately 30 wt pct Ni, a wide scatter in the reported habit planes exists. In only one instance has a Laue determination of the orientation relationship been made, but the habit plane of the martensite plate studied was not determined experimentally. Because the most successful thermodynamic and kinetic analyses8 of the martensite transformation have been based on Fe-30 Ni alloys, it was considered desirable to reinvestigate the crystallographic features of the transformation in this alloy. Lieberman9 suggested that the most significant information for use in a theoretical treatment involves the determination of all the crystallographic observables from a single plate of the product phase. This was first done in essence by Greninger and Troiano10 for Fe-22 wt pct Ni-0.8 wt pct C, and is the method followed in this investigation. Some theoretical approaches11-13 in describing the martensitic transformation consider the overall transformation distortion to be comprised of a Bain distortion, or lattice deformation (PI, which produces the structure change, and a lattice invariant deformation (G), such as twinning, which together leave the interface or habit plane un-distorted. The incorporation of a rigid body rotation (R) results in a transformation distortion (E) such that the interface plane is left both undistorted and unrotated. In matrix notation, E = RPG where the lattice invariant deformation has "taken place" in the austenite. Bowles and Mackenzie14-16 in formulating a theoretical approach proposed an adjustable scaler quantity, denoted as 6, which represents a uniform dilation in the interface plane. This dilation acts to adjust the lattice spacings of the parent and product structures at the plane of contact. Using the dilation parameter as a variable, these authors were able to account for a continuous variation of habit planes in steels along a curve in the stereogram between {225}A and {259}A. she invariant line strain14 of the transformation is 6 RP, and the corresponding transformation distortion is E/6.) With the dilation parameter known, the invariant line is computed as the triple coincidence of the habit plane, the shear plane of the lattice invariant deformation, and the initial Bain cone.14 The contraction axis for the Bain distortion can be taken9&apos;17 as [010]A, and the correct permutation of the habit plane indices used. Kelly and Nutting 18 have established the shear plane (of twinning) in the tetragonal martensite of Fe-22 Ni-0.8C to be {112)M by means of transmission electron microscopy. The reasonable shear system is then {112}M which is equivalent to {011}A <01l>A. The as-

Jan 1, 1962

By O. B. Buchlen, J. W. Smith

The Coal Research Bureau of the School of Mines at West Virginia University, using an experimental flotation cell designated an airlift-cyclone was able to obtain a clean coal product containing 7.64% ash with 94% yield and 97% coal recovery. This favorable performance was obtained with the experimental flotation cell operating as a simulated three-stage unit on slurry taken from the fine coal circuit of a coal preparation plant. This experimental device, consisting of a sheet metal cyclone-like unit mounted on a U-shaped uplift pipe, uses a combined flotation and cyclone action to beneficiate the minus 14 mesh partially cleaned feed product. In addition to providing comparable analytical results, the airlift-cyclone possesses other attractive features among them being a low capital expenditure, utilization of moderate plant floor space, efficient operation on high density feed slurry, and absence of moving parts. The primary shortcoming of the experimental cell is its limited capacity. The Coal Research Bureau presently has under construction a larger unit which, it is hoped, will provide the capacity and quality to establish the airlift-cyclone as a commercially feasible unit. Froth flotation of fine coal is a practice which has only recently gained wide acceptance in this country. Various explanations can be put forth for this delayed acceptance of a very selective and efficient system of coal preparation. Among these reasons would be the advent of continuous mining machines resulting in the increased production of coal fines, the change in market patterns from domestic and rail consumers who did not want fines to a predominantly utility market which normally consumes fines, and also the imposition of legal restrictions in regard to stream pollution. However, the major detriment is probably the high cost involved both in installation and operation of the flo- tation unit and auxiliary systems. These facts assume greater emphasis when considering that froth flotation installations normally process a low quality feed product. A recent estimate&apos; of installation costs including dryers, filters, and other auxiliary equipment for a flotation system was $5000 to $7000 per ton of capacity while the operating costs, exclusive of auxiliary equipment, were estimated at 10 to 306 per ton of feed. The Coal Research Bureau of the School of Mines at West Virginia University is currently developing a simplified froth flotation cell, designated an airlift-cyclone, which may provide considerable savings in capital and operating costs without sacrificing product quality or recovery. This experimental cell consists of three primary components: 1) a vertically mounted U-shaped pipe; 2) an air injector device; and 3) an integrally mounted cyclone-like unit (Fig. 1). A feed slurry is introduced at the top of one leg of the U-pipe while compressed air is injected near the base of the other leg. The air serves both to aerate the pulp and to cause it to flow upward into the base of the cyclone unit where the floated clean coal is separated from the reject material and unfloated coal which remains in slurry. The Coal Research Bureau&apos;s experimental airlift-cyclone is somewhat similar in principle to a flotation device developed by Russian engineers in the late 1950&apos;s. In tests upon a two-stage pilot-size device, the Russians obtained very favorable cleaning efficiencies.&apos; However, later experience with production models demonstrated that rated capacities and acceptable product quality could not always be maintained.3 Because of these limitations, Russian engineers subsequently recommended that conventional, mechanical cells be used when cleaning difficult to float slurries. Engineers at the Coal Research Bureau felt that such a device utilizing the combined actions of a cyclone and a froth flotation machine offered numerous attractive features and merited investigation. Accordingly, a small capacity experimental airlift-cyclone was designed and, with the permission of the Christopher Coal Company Div. of Consolidation Coal Co., installed in Christopher&apos;s Humphrey preparation plant near Morgantown, West Virginia.

Jan 1, 1964