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By C. R. Whitney, G. N. Maniar, D. R. Muzyka

Previous results have shown that Pyromet 860, an Fe-Ni-base heat-resistant alloy, is stable at temperatures as high as 1500°F for aging times as long as 100 hr. This Paper describes the results of long-time creep-rupture testing at 1050" to 1400°F at various stress levels. Times as long as 37,660 hr were employed. The effects of time, temperature, and stress on the precipitates and their morphologies were studied by optical and electron microscopy, X-ray and electron diffraction, and microprobe techniques. phase, containing cobalt, nickel, and molybdenum, was detected after extended exposures from 1200" to 1400°F and careful study was performed to describe the kinetics of its formation in this alloy. µ phase formation apparently has little effect on the elevated-tem-perature properties of Pyromet 860. For times as long as 500 hr at 1300°F and below, with µ phase present, m significant effects on ambient temperature properties were noted. For longer times at 1300°F and after 1400°F exposure, the effects of u phase on ambient temperature tensile strength properties are not clear due to y' effects and grain boundary reactions. Electron-vacancy, N,, numbers were calculated using different methods described in literature and correlated with the present findings. In the selection of alloys for use in gas turbine applications, structural stability ranks as a primary criterion. High-temperature strength and cost are also of major concern. With these factors in mind, Pyromet 860 alloy, an Fe-Ni-base superalloy was designed. This alloy combines the cost advantages of Fe-Ni-base alloys such as A-286, 901, and V-57 with improved strength and structural stability'1,2 and no tendency to form the embrittling cellular 77 phase. A previous study3 reported on the stability of Pyro-met 860 at temperatures from 1375" to 157 5°F and times up to 100 hr. That study showed that the y' precipitates increased in size and separation and decreased in number with an increase in time or aging temperature. No deleterious phases were found to occur. In the present work, samples from four production heats were subjected to long-time creep-rupture testing at 1050" to 1400°F at various stress levels. Various heat treatments were used on the starting samples and tests were run up to 37,660 hr. The effects of time, temperature, and stress on the precipitates and their morphologies were studied by optical and electron microscopy, X-ray and electron diffrac- tion, and microprobe techniques. Electron vacancy numbers, Nv , calculations were made by TRW.4 Experimental results are correlated with the Nv data used to predict occurrence of intermetallic phases such as a phase. EXPERIMENTAL PROCEDURE Mechanical Tests. Material for the present study came from four production size heats of Pyromet 860 alloy, weighing from about 3000 to about 10,000 lb. All of these heats were made by vacuum induction melting plus consumable electrode vacuum remelting. The nominal analysis for this alloy is compared with the actual analysis of the four heats in Table I. Sections of these heats were forged to 9/16-in. round bar,3/4-in. square bar, 3-in. round bar, 4-in. square bar, and a gas turbine blade forging about 16 in, long, about 6 in. wide, and weighing about 20 lb. In general, all forging of this alloy is done from a 2050°F furnace temperature. Longitudinal test blanks were cut from the centers of the smaller bars, from mid-radius positions for the 3- and 4-in. bars, and from the air foil of the gas turbine blade and heat-treated according to the procedures outlined in Table 11. Heat treatment A is the "standard treatment" recommended for this alloy for best all-around strength and ductility. Heat treatment B is a modification of treatment A for improved tensile strength at moderate temperatures. The treatment coded C was designed for treating large sections according to a procedure previously described.' Heat treatment D was developed to yield optimum stress relaxation characteristics at 1050°F for a steam turbine bolting application. After heat treatment, the test blanks were machined either to plain bar creep specimens with a gage diameter of 0.252 in., to combination smooth-notched stress-rupture bars with a plain bar diameter of 0.178 in. and a concentration factor of Kt 3.8' at the notched section, or to notch-only specimens. All specimens conformed to ASTM requirements. Metallography. Most of the creep-rupture tests were continued to failure. A few bars were fractured as smooth or notch tensiles after creep-rupture exposures. After fracturing, ordinary metallographic sections were made primarily in gage areas adjacent to fractures to represent a "high-stress" region and through specimen threads to represent a "low-stress" region. All metallographic sections were made in a longitudinal direction with respect to the test specimen axes. For optical microscopy, the samples were etched in glyceregia (15 ml HC1, 5 ml HNO,, 10 ml glycerol). For XRD analysis, the phases were extracted electrolytically in two media: 20 pct &Po4 in H20 for selective extraction of y' and 10 pct HC1 in methanol for carbides and other phases.

Jan 1, 1970

By AIME AIME

IN times of stress nations pick strong men to lead them. Similarly the Coal Division selected forceful Larry A. Shipman, fuel engineer for the Southern Coal and Coke Co., Knoxville, Tenn.. to lead it through the year 1945. He was born in Indianapolis May 13, 1891. Following graduation from a technical high school in that city Larry began his fuel career approximately 35 years ago attached to one end of a scoop shovel, firing locomotives for the Pennsylvania Railroad. At the end of two years he transferred to the New York Central Lines and held these jobs successively: locomotive fireman, engineer, fireman instructor, supervisor of instructors, and fuel engineer.

Jan 1, 1945

By William B. Plank

AN outstanding development in the field of education for the mineral industries during the past year has been an unprecedented eagerness by young men for college training in this field. The enrollment of students in the 53 mineral technology schools in the United States in 1936-'37 reached the all- time high of 7190. This represented an increase of 43 per cent in two years and was about ten per cent of all engineering students. Of these 7190 students only 980 graduated and were available - for positions in the industry. That the supply of graduates did not equal the demand can be substantiated by every school dean and by the personnel agents of many mining, metallurgical, and petroleum companies. Some of these companies last summer inaugurated the plan of employing, for the

Jan 1, 1938

By E. A. Breitenbach

A computer program has been developed to afford rapid and complete quantitative log analysis for exploration and production decisions. The computation consists of automatic selection of tops and bottoms of porous intervals from the digitized data, and then point-by-point calculations within each selected interval. Nearly all log types can be analyzed. This paper presents the calculation techniques found to be appticable to machine evaluation and gives examples of their use. INTRODUCTION As the quantitative interpretation of well logs entails repetitive use of charts and equations, it is natural that digital computer programs would be written. A Universal Log Interpretation Computer Program (ULICP) has been developed to afiord rapid and complete analysis for exploration and production decisions. Application of this program enables the log analyst to: (I) apply rapid quantitative log analysis for exploration and production decisions on either a field, a well or on a single zone basis; (2) apply concepts of interpretation requiring detailed numerical analysis; (3) analyze all porous intervals on each log, rather than a few selected zones, and complete the analysis in less time than previously required. Computations are reported for every digitized point in each zone; (4) use empirical techniques applicable to a given area as an integral part of the computation; (5) experiment with the empirical coefficients and exponents in the interpretation equations to find the best possible solution; and (6) automatically plot both the original and computed data to scales analogous to the field prints. The primary utility of a log interpretation program stems from its ability to do an overwhelming amount of work with very little man-power. If a calculation procedure or thought process can be formalized to the extent that step-by-step logic can be written, a computer program can be developed that follows this logic. The major question is one of economics. A feasibility study of the costs for such a program indicates that digital processing is economical primarily as a means of increasing the productivity of the log analyst. In effect, the probability of missing productive intervals in any well, because of a lack of time to do detailed calculations, is greatly reduced. The nucleus of ULICP is programmed to compute large sections of a suite of logs by selecting zones automatically and then performing all pertinent computations on a data point by data point basis within each zone.'.' An entire suite of logs can be processed in this manner with very little manual intervention. Sufficient programming logic is available so that each log analyst can request computations pertinent to his area. These requests are made by simple additions or deletions of information on the input header cards. Hence, the log analyst is always in complete control of the computation process. The evaluation of a suite of logs requires pre-editing, digitization, computation, presentation of results and interpretation. Work by the log analyst is reqilired only in pre-editing and interpretation. Thus, he is allowed more time for comprehensive interpretation, rather than calculation. For continuity, the discussion of ULICP is organized sequentially: pre-editing, digitization, computation and presentation of results. DISCUSSION PRE-EDITING The extent of pre-editing prior to computation is dependent on the format of the original data. For analog prints, it requires inspection, correlation and editing of the logs, plus the entering of required data an special forms. For digitized data such as magnetic tape field recordings, only the special forms are necessary. The process for analog prints will be given here. The inspection and correlation process involves the selection of sections for digitization and the correlation of the traces to a common depth. To decrease the cost of digitization, traces that exhibit large variations in shale formations can be redrawn to a non-zero baseline. The next step is to enter all pertinent data on the input header cards. The header cards presently used for ULICP are presented as Figs. 1 through 6. Cards 1, 2, 3 and 4 (Fig. 1) are defined as the Main Header Cards. They describe the particular well for output identification and give basic information. Cards 5 through 15 (Figs. 2 through 6) are defined as the Block Header Cards. As such, they define the log types and the interpretation parameters for the block of data immediately following. Cards 1 through 10 are required for every computer run. Cards 11 through 14 pertain only to nuclear logs. Card 11 is required if any nuclear log is supplied, and cards 12 through 14 are required only when gamma-ray, density or neutron log data, respectively, are supplied. Card 15 (Fig. 6) must be supplied when cross-plot calculations are required. Either two- or three-component

Jan 1, 1967

By P. J. Jacquard, C. Jain

Interpreting pressure measurements is one of the fundamental problems in the operation of oil reservoirs. The principal methods and means of study zuhich are currently used are reviewed. Emphasis is placed on the necessity of improving the quality of the information to turn it to the best possible account. One of the important aspects of the problem is the development of a system of automatic interpretation of the pressure measurements. The proposed method aims at this objective: starting from the relation which exists between a local perturbation of permeability and its effect on the velocity potentials in the wells, we determine by successive approximation the modifications to be made to the permeability map by fitting the least squares between the measured pressures and the pressures indicated by the mathematical model. The method has already been successfully employed in the case of heterogeneous reservoirs of radial- circular symmetry. Its application is extended here to the two-dimensional case, and is illustrated by two examples, for which the results are presented. The conditions required for the method to become fully operational are likewise analyzed. I — INTRODUCTION One of the basic problems of production and recovery from oil fields is interpreting pressure measurements made in wells in the single-fluid-phase regime. Simplifying assumptions, for example supposing the reservoir to be homogeneous, make it possible to use more or less simple methods which permit the estimation, from these pressure measurements, of a mean value of the permeability around the wells. Considering the actual heterogeneity of the majority of reservoirs, and the phenomena of interference between wells, these methods are only indicative. Much has been published on the studies of different cases of comparatively simple heterogeneity: some have discussed the radial heterogeneity around a single wel1,l or vertical heterogeneity.2 The results of these works have shown the influence of variations of permeability on the pressure, but unfortunately they are not very useful in practice because they all are concerned with the phenomena around a single well, without interference between wells, and they correspond to relatively simple and theoretical schemes. These studies of reservoirs or parts of reservoirs on a larger scale are made by the electric analyzer or digital model. We define a permeability map and a porosity map, then reproduce the production history of the wells on the wells of the model, and note the corresponding pressures. These pressures are then compared with actuality, and the discrepancies observed are analyzed. From this analysis we deduce the modifications to be made to the maps of permeability and porosity, and repeat until the coincidence between the pressures indicated by the model and the actually observed pressures is considered adequate. We have adjusted the model. Obviously, in this method of investigation, everything depends on the formula which permits the modification of the permeability to approach the adjustment. Considering the complicated nature of the problem, some oversimplified formulas are poorly adapted to reaching a good adjustment. For example, we have shown that the elementary operation of increasing the permeability not far from a producing well to compensate for too low pressures in the well can, in certain cases, express itself by an effect exactly opposite. 3 The project described here is for a system where we begin with the pressure measurements and the several known parameters of the reservoir, and develop the most probable permeability map, taking account of the measurements available and a subdivision of the reservoir fixed a priori. Ideally, this system is conceived as one in which no manual intervention would be necessary. The model simulating the reservoir is only one part of the whole system, and it is neither the longest nor the most complex part. The need to integrate the model into an aggregate of much more extensive processes has led to the adoption of the digital solution, even though a solution combining the digital and the analog is perfectly conceivable. The simulating model is in that case no more

Jan 1, 1966

By Geo. W. Bain

PRODUCERS of building stone have had to seek new and attractive uses for their output to supplement the diminished orders for standard products. Lunar is the direct result of the need of new outlets for marble and is. probably the most ingenious and attractive type to reach the market in a quarter of a century. It is a highly translucent stone which retains the same glistening sparkle in transmitted light that marble exhibits by incident rays. This sparkle sets it apart entirely from translucencies made of glass or even onyx, alabaster, and the distinctive exceedingly fine textured calcite marbles produced in Alabama and quarried formerly in northern Vermont and Quebec.

Jan 1, 1936

By H. W. Meyer, H. N. Lander, F. D. Delve

A method of calculating the changes in blast-furnace performance brought about by burden and/or blast modifications is presented. Essentially the method consists of three simultaneous equutions derived from materials and heat balances. These equations can be used not only to evaluate quantitatively the effect of changes in process operating variables on furnace performance, but also to provide a useful means of evaluating changes in process variables which cannot be measured directly. It has been customary for a number of years to use simple heat and materials balances as a basis for assessing blast-furnace practice. A good example of the method used to set up these balances is that proposed by Joseph and Neustatter.1 This approach to process assessment has limited utility, however, in that it cannot be used to predict the furnace coke rate or production under new operating conditions. Using an approach based on multiple correlation of blast-furnace variables, R V. Flint2 has developed an equation which may be used to predict the change in coke rate that will result from some changes in operating conditions with a reasonable degree of accuracy. Although this equation has useful applications in production planning, it cannot be used to study the relationships between the operating variables and the fundamental thermochemi-cal characteristics of the process. In attempting to analyze the blast-furnace process quantitatively, the idea of dividing the furnace into zones3 may at first appear attractive. In our present state of knowledge, however, it is not possible to define with any accuracy the physical limits of such zones in relationship to their temperatures or to the reactions which may occur in them. Although its application is restricted, the zonal approach to blast-furnace analysis is useful in some instances. For example, the change in the calculated flame temperature in the "combustion zone" caused by injecting steam constitutes information which is helpful in understanding why the addition of steam to the blast is best accompanied by an increase in blast temperature. The zonal approach cannot, at the present time, be used to establish the relationships between process variables and process performance if the whole process rather than part of it is to be considered. One of the earliest approaches to the problem of relating blast-furnace operating variables to pro- duction and coke rate was that developed by Marshall.4 Essentially Marshall's work showed that it was possible to estimate the performance of a furnace by solving three simultaneous equations which consisted of rudimentary carbon and heat balances plus a further equation relating the production, wind rate, and the carbon burned at the tuyeres. Although these equations did not include all of the chemical and thermal variables of the process, their derivation and application seems to be the earliest attempt which achieved any success in relating prior furnace operating data to the calculation of furnace performance under different blast conditions. Work carried out in Germany has been directed mainly towards prediction of coke rates using material and thermal balances rather than statistical methods. wesemann5 used prior furnace operating data as part of the basis for predicting the change in coke rate accompanying a change in burden composition. This author employed a method of successive approximations to estimate the secondary changes in slag volume and stone rate brought about by the change in coke rate. The most recent analysis, which seems to have been developed concurrently with the thermochemical model presented in this paper, has been described by Georgen.6 This author has succeeded in improving on Wesemann's approach by expressing the total changes in the slag volume and stone rate in terms of the change in coke rate itself. This is accomplished in a manner similar to that used in the thermochemical model described in this paper. Although Georgen makes use of a calculated furnace heat loss, he does not relate the heat loss per unit of hot metal to the production rate as is done in the present work. Georgen's approach may be used to calculate the changes in materials requirements accompanying changes in furnace operation; it cannot be used to assess the resulting changes in production. The fact that blast-furnace behavior can be interpreted by consideration of the heat requirements of the process was demonstrated by Dancy, Sadler, and Lander.7 In the analysis of blast-furnace operation with oxygen and steam injection these authors showed that it was possible to account for the changes in production and coke rate

Jan 1, 1962

By P. L. Weston, S. E. Khalafalla

A systematic study was made by the Bureau of Mines on the effect of so me hypothesized accelerators for the process of wustite reduction in carbon monoxide. When small concentrations of promoter materials in the order of 0.69 at. pct were added to the reducible charge, the rate of reduction to iron was increased. Promotion phenomenon prediction was made in light of a suyface reduction mechanism with the aid of Vol'kenshtein's effect regarding the propagation of crystal lattice disturbances by small amounts of relatively larger interstitial ions. The acceleration produced by a typical promotor, such as potassiunl, increases with protnoter concentration up to a maximum, beyond which the reduction rate decreases. Concentration for maximum promotion depends on the nature and physicochemical properties of the promoter. The extent of reduction rate enhancement is found to be directly proportional to the atomic volume and electronic charge of the additive. DESPITE the enormous volume of literature on iron oxide reduction, very little is reported concerning additive or impurity effects on this important metallurgical process. The beneficial effect bf calcium compound additions on the reducibility of iron oxide sinters has been reported by Tigerschiold,1 vor dem Esche,2 and Edstrom. Doi and Kasai~ found that the addition of lime or limestone to iron ores helps to break up any unreducible compounds, such as fayalite or ilmen-ite. and thus free the combined iron for reduction. Schenck et al. 5 suggested that the increased reduction rate obtained when adding lime could be accounted for by the instability of wustite in the presence of lime. Acid-base slagging reactions resulted in wustite disproportionation according to The dicalcium ferrite formed will yield iron and calcium oxide during reduction. Regenerated calcium oxide dissociates more wustite. This mechanism has been used by Seths and white7 to explain their experimental results. Recently, Strangway and ROSS' attributed the calcium carbonate acceleration of iron oxide agglomerate reduction to increased porosity, both initial as well as that developed during reduction. Aside from calcium carbonate, or oxide, no other promoter was noted in the literature, except for a brief mention by Barrett and woodg on the effect of sodium carbonate and aluminate as activators for the hydrogen reduction of magnetite at 600°C. The present investigation systematically studied a host of other promoters, including calcium and sodium, in an attempt to elucidate the mechanism by which promotion takes place and to fit the results into a simple chemical model. To attain this goal, the effect of promoter physical properties, such as atomic volume, electronic charge, and concentration are related to wustite reduction kinetics in this paper. Wustite reduction to iron, rather than the overall hematite reduction, was chosen since this reaction is known to be the slowest, and hence the rate-deter mining step for the overall iron oxide reduction process. EXPERIMENTAL PROCEDURE Raw Materials and Their Preparation. The pure or impregnated wustite pellets were prepared from minus 400-mesh chemically pure hematite powders. A known weight of hematite was thoroughly and uniformly mixed with a calculated weight of the additive. The mixed paste containing 35 wt pct water was gradually heated from 400" to 1200° C and fired at 1200°C for approximately 4 hr in an air atmosphere. After cooling, the sinter was pulverized to minus 100 mesh and pelletized into minus 4- plus 5-mesh spheres. Pellets were fired, similarly to the paste mix, air-cooled, sized, and stored. An appropriate weight of the charge (20 g) was placed in a zirconia reduction tube maintaining a uniform oxide bed height of 1 cm and a cross section of 7.1 sq cm for all of the test runs. The samples were supported in the vertical reaction tube by a bed of fragmented insulating firebrick plus 3- to 6-mesh alumina beads. The hematite was then transformed to wustite by reduction with a 30 pct CO2-70 pct CO gas mixture at 1000°C in a globar furnace. Complete conversion to wustite was ascertained by a continuous infrared gas analyzer recording the CO-CO2 content of the effluent gas until no carbon monoxide was absorbed from the inlet gas, and inlet-outlet gas analysis remained constant for 30 min. The wustite sample was then reduced with 100 pct CO at 100WC. From the recorded data, an initial rate of reduction was determined by the initial slope of the graph percent reduction vs time. In order to estimate the accuracy of the data, five separate determinations of the reduction curve of pure wustite, under otherwise identical conditions, were performed. The maximum deviation from the average reduction at 14 min amounted to 2 2 pct reduction. This deviation corresponds to 3.8 pct variation based on the percent reduction of the sample. Aiiy impurity effect below the limits of this maximum deviation was considered a spurious result. If the effect exceeded + 4 pct, then it was considered as a positive one. Considerable care was exercised in determining the initial rate from the slope of the initial segments of the curve. Each reduction curve was examined separately on large graph paper and the best tangent to the curve at zero time was drawn. The slope of this tangent was taken as a measure of the initial fractional reduction per minute. Although the time required to reach 50 pct reduction may be of special practical significance, initial rate measurements are invaluable in fundamental studies. These rates provide a measure of the process kinetics on the initial

Jan 1, 1968

By L. C. Graton

The federal taxes on incomes and excess profits are of course heavy. In 1917, the value of the mineral production of the United States was a little in excess of $5,000,000,000. The total of federal taxes for that year, for the mineral producing companies, as computed by themselves, amounts, according to tentative compilations, to about $207,000,000, and the total for the comprehensive group of mineral and metal industries to about $766,000,000, which figures represent respectively 9.5 per cent. and 35.1 per cent. of the total tax paid by all corporations. Because of greater complexities in applying the revenue laws to mineral properties than to most other industries, opportunity is afforded for wide differences of view. The taxes indicated above, therefore, are not final and may conceivably be very materially increased. For 1918, the taxes are expected to be still greater, but no compilations are yet available. Taxes at a high rate are to continue indefinitely. The subject is clearly of gravest import to the mining industry in particular. The Commissioner of Internal Revenue, who is charged by law with the administration and collection of the taxes, is determined that these functions shall be performed in a just and businesslike way. Fairness and finality are to be the chief objectives. In view of the peculiar conditions that attach to the tax program as applied to mines and other wasting industries, like oil, gas, and timber, the Commissioner has resorted to professional advice and assistance by manning a Sub-division of Natural Resources with competent engineers, brought in from the several industries, into whose hands he has placed for solution the technical questions involved. These engineers have a two-fold duty: (1) to devote to the solution of these problems their own knowledge and experience; (2) through their acquaintance with their respective industries, and with the men engaged in those industries, to focus upon these problems, by conferences and otherwise, the best opinion of the country. The principal object of this paper is to acquaint the mining profession with the attitude of the

Jan 1, 1923

By L. C. Graton

The federal taxes on incomes and excess profits are of course heavy. In 1917, the value of the mineral production of the United States was a little in excess of $5,000,000,000. The total of federal taxes for that year, for the mineral producing companies, as computed by themselves, amounts, according to tentative compilations, to about $207,000,000, and the total for the comprehensive group of mineral and metal industries to about $766,000,000, which figures represent respectively 9.5 per cent. and 35.1 per cent. of the total tax paid by all corporations. Because of greater complexities in applying the revenue laws to mineral properties than to most other industries, opportunity is afforded for wide differences of view. The taxes indicated above, therefore, are not final and may conceivably be very materially increased. For 1918, the taxes are expected to be still greater, but no compilations are yet available. Taxes at a high rate are to continue indefinitely. The subject is clearly of gravest import to the mining industry in particular. The Commissioner of Internal Revenue, who is charged by law with the administration and collection of the taxes, is determined that these functions shall be performed in a just and businesslike way. Fairness and finality are to be the chief objectives. In view of the peculiar conditions that attach to the tax program as applied to mines and other wasting industries, like oil, gas, and timber, the Commissioner has resorted to professional advice and assistance by manning a Sub-division of Natural Resources with competent engineers, brought in from the several industries, into whose hands he has placed for solution the technical questions involved. These engineers have a two-fold duty: (1) to devote to the solution of these problems their own knowledge and experience; (2) through their acquaintance with their respective industries, and with the men engaged in those industries, to focus upon these problems, by conferences and otherwise, the best opinion of the country. The principal object of this paper is to acquaint the mining profession with the attitude of the

Jan 1, 1923

By J. R. Vilelia

IN accordance with the custom of this society, we are gathered here, as we have every year since 1924, to honor the memory of the eminent American metallurgist and teacher, Professor Henry Marion Howe. Unlike many of the distinguished metallurgists who have preceded me as a Howe lecturer, I cannot bring to you reminiscences of his personality, for it was not my privilege to be associated with Professor Howe, or to be directly one of his students. Yet, Professor Howe and Professor Albert Sauveur, through the medium of their books, were my first teachers of metallography, as they have been of almost all American metallurgists of my generation. As a teacher, and for many years the acknowledged leader of American metallurgists, he exercised a profound influence in the growth of our science and was held in honor by the men of science of his time. I can speak no words of technical appreciation that will add luster to his fame, for by his prophetic vision, his teachings, and his researches he stands among the immortals in the memory of all metallurgists. In 1926, the third Howe Memorial Lecture was presented by Professor William Campbell' of Columbia University, who entitled it "Twenty-Five Years of Metallography." He took as a starting date for his chronology the turn of the century, which coincided with his arrival from England to work in association with Howe at the Columbia School of Mines. In that informative lecture Professor Campbell enumerated the important advances in metallography achieved during the first quarter of the century, and, it now appears, may have established the custom of reviewing such progress every twenty-five years. The scope of Professor Campbell's lecture was as broad as his metallurgical knowledge, for it embraced a wide portion of the field of metallography, both ferrous and nonferrous. Twenty-five years later, the Howe Memorial Lecture Committee saw fit to assign to me the honor of writing a lecture that would commemorate the work of Henry Marion Howe and would at the same time constitute the 25th anniversary of the lecture by Professor Campbell. The Committee suggested that this lecture might properly be called "Twenty-Five More Years of Metallography," a suggestion that I have adopted. I must confess, however, that I have not followed the precedent established by Campbell and have narrowed the scope of this lecture to an appraisal of those achievements which in my opinion have contributed most to the progress of microscopical metallography during the past twenty-five years. Progress in Metallography The metallographic methods most widely used today, with the exception of the electron microscope, were firmly established more than twenty-five years ago. In general, our specimens were prepared for microscopic examination in those days in much the same manner as they are today. It is true that new details of technique have been introduced from time to time, and that superior equipment is available today, but on the whole, these improvements have been in the nature of refinements, often a matter of personal preference, and none can be considered essential to the attainment of the ultimate goal of the art and science of metallography, which is to reveal the structure of metallic specimens with unequivocal clarity so that they may be interpreted correctly. Mechanical metallographic polishing, which was the only method available in 1926, is still universally practiced and still consists of abrading the metallic specimen with a series of abrasives of increasing fineness until a specular surface is attained. We have now the alternative method of electropolishing, but it is not widely used because, except in a few special cases, its results are inferior to those of competent mechanical polishing. Likewise, most of the etching reagents preferred today were in common use more than twenty-five years ago and were applied in the same manner as they are today. Valuable improvements have been made in the optical and mechanical performance of metallurgical microscopes, but there was no dearth in those days of excellent instruments equipped with achromatic and apochromatic objectives capable of yielding micrographs comparable in quality with the best that we can make today. In fact, it would be a difficult task for any metallographer today to make optical micrographs at magnifications in excess of 3000 diameters that would surpass those made by Lucas more than twenty-five years ago. One of these is shown in Fig. 1. Yet, it is unquestionable that on the whole, the micrographs appearing in the metallurgical literature today are vastly superior to those

Jan 1, 1952

Frank H. Probert, A.R.S.M., Morenci, Arizona (communication to the Secretary): The management of mines and the system of bookkeeping employed are subjects of great interest to mine-superintendents, and such papers as that of Mr. Davis callnot fail to attract attention. The Institution of Mining and Metallurgy, London, England, has done much within the last three years to promote discussion on the many systems adopted throughout the mining world; and any papers giving individual experience will benefit that class of men who are charged with the cconomical management of mining properties. It is often said that " a good mine shows a good manager," and more often that mismanagement is the chief cause of poor returns; or, as Mr. A. G. Charleton puts it, in his able paper on " Mining Accounts and Cost-Sheets,"* " accident may, and often

Jan 1, 1902

By V. J. Sikora, T. S. Hutchinson

This paper presents a method for making a water-rlrive ana1gsis without prior knowledge of aquifer geometry and uniformity using a standard desk calculator. Although it is necessary to know the initial oil in place to use this method, this is a minor limitation to the scope of (he method since in most reservoirs it is possible to obtain reasonably accurate volumetric oil-in-place estimates. An equation is developed which relates pressure at the water-oil contact to the water influx rate as a function of time by a factor called the resistance function. The resistance function introduces the composite effect of the aquifer geometry and flow resistance disrribution. It is pointed out that the characteristic shape of this function makes it possible to start with on approximation of the function and successively improve the approximation until the correct resistance function curve is obtained. In this fashion water-drive estimates can be made without the limitation of assuming simplifed aquifer shapes and flow distributions. This is the novel feature of this development. Methods are given for extrapolating the final curve to calculate future aquifer behavior. Equations are developed for adjusting the pressures and water influx rates where it appears that possible errors in these quantities make it difficult or impossible to obtain a useuble resistance function curve without this adjustment. Application of the pressure build-up analysis techiiique to estimate. some of the aquifer properties is also presented INTRODUCTION A great many oil pools are the result of oil accumulation in some type of trap in an otherwise large and continuous porous stratum. The void space of this stratum outside of the oil pool itself is filled with water or brine. In analyzing performance of the oil pool surrounded by this water aquifer, it is quite necessary. in most cases, to include behavior of the water. When the pressure at any point in a fluid system is lowered, such as by opening a well in an oil sand, fluids in the immediate neighborhood of this point will begin flowing towards this lower pressure sink. As pressure in this area drops due to flow towards the sink, fluids from farther out will start to flow towards the lower pressure. As more and more fluid is removed from the system, the distance from the sink or well within which flow is occurring will continually increase; that is, thc region of disturbance will grow. If some rigid boundary such as a fault is reached by the disturbance, this area will cease to grow; but if some movable boundary is reached, such as a water-oil contact, the area will grow on out into the water, although rate of growth may and almost always does change. The relation between amount of pressure drop and amount of fluid flowing at any point and at any time in an aquifer depends on such factors as compressibility and viscosity of the fluids, the porosity and permeability of the rock, geometry of the whole system and withdrawal rate or pressure drop. With these factors known, it is theoretically possible to calculate the pressure-flow behavior of the system, However, in practice true solutions to the problem are next to impossible due to complexity of reservoir systems. A number of approximate methods of solution have been developed based on various simplifying assumptions. One frequent assumption is that the water-oil contact can be located and equations defining oil reservoir and aquifer solved separately by assigning values to various parameters so as to match past pressure and production history. Usually the properties of the aquifer are not known, since few, if any, wells are drilled through the aquifer; but the water influx and the pressure at the reservoir boundary are known over some time. If it can now be assumed that the aquifer is circular, pie-shaped, or linear, and that it has uniform properties, it is possible to fit a theoretical dimensionless curve to the past aquifer performance history and therefore calculate future water drive. These theoretical curves are available in the literature,1,2,3 Of course, the assumption of uniform aquifer properties is almost always somewhat in error. Fortunately, however, moderate variations from the average have little effect on behavior of the system; and, hence, the best fit of a theoretical curve is frequently satisfactory. In other cases variations in aquifer properties and geometry are large enough that none of the available theoretical curves will give an acceptable fit of the data. In these cases, methods of fitting the data with various electrical analyzers have been developed.1,2' It is the purpose of this paper to present an approach

By AIME AIME

A STUDY of subsidence and ground movement in the copper and iron mines of the upper peninsula of Michigan has been made by W. R. Crane of the United States Bureau of Mines and published as Bulletin 295 of 66 pages and 49 illustrations. As a result of subsidence, the country adjacent to the mines and over- lying the mine workings in this district is often broken to such an extent as to affect its value; mine shafts and development openings are occasionally so damaged as to be rendered useless, and water can enter the workings through fractures and cave-ins. The problem is more serious in the iron-mining districts, where villages and towns not owned by the operating companies have grown up around mining operations.

Jan 1, 1929

By Basil B. Zavoico

ALTHOUGH the American petroleum industry was affected by the Second World War from its early beginning it was not until Dec. 7, 1941- that the industry was placed on full war footing. Even throughout most of 1942 the American overseas operations were limited and not until late in the year did expansion of military activities, more particularly the offensive in North Africa, affect the domestic supplies to such an extent that critical deficiencies developed locally in this country, particularly along the East Coast. The definite outlook for greatly expanded offensive operations by the United States on both Atlantic and Pacific fronts makes certain that during 1943 the domestic situation will. not be alleviated; rather it may become even more critical even though additional transportation facilities, now being built and planned. will be completed from the southwestern producing states to the East Coast.

Jan 1, 1943

By William G. Kegel

Apart from a usable product and good mining conditions, the greatest asset for a profitable coal mining organization is an effective mine maintenance program. The first step in achieving this is to have good mechanics-or men who want to be mechanics and are interested in knowing ,more about the design and control of the machines in their charge. A good mechanic's knowledge and ability result from ambition, curiosity, and determination. Starting with these qualities, the aspiring mechanic can launch his career by learning all he can about mechanics, electricity, and hydraulics. Though the path is rough, the end result is rewarding. Mining machinery probably receives as much, if not more, abuse as any other heavy equipment in use today. Considering the conditions under which much of the repair work must be done, it is essential that the mine operator has the best men and tools to perform the work. Mining machines, from their inception, have utilized the electric motor ; and down through the years of mechanization, this power source has undergone many changes to better adapt it to the job. The first motors used were direct-current (d-c) motors since d-c power was the most economical power source for mining at the time of early mechanization. These motors were large open-type machines which are seldom used in modern mining. Because of the mine environment, the d-c motor has been reduced in size to better suit the application in mining machines and is now manufactured with dust-tight or explosion-proof enclosures. The d-c motor is constructed with either (or both) series and shunt fields located on the stationary part of the motor (stator) and an armature coil wound on the rotating part of the motor (rotor). Power is supplied to the armature by brushes which are held stationary and make sliding contact with the armature. The brushes requires regular and careful maintenance because worn or defective brushes will cause heat or arcing which can destroy the motor. D-c motors can be used as d-c generators when mechanical power is supplied to them by the rotating

Jan 1, 1981

By T. A. Wilson

THE plastic deformation of slender single crystals of zinc has been described in some detail in the paper by Mark, Polanyi and Schmid,1 which has become a classic, and also by one of the present authors in a somewhat shorter account.2 The study of single-crystal zinc is termed classical because zinc single crystals offer, perhaps, the best material yet available for the study of atomic behavior during deformation and the effect known as "strengthening" in metals. A considerable amount of additional work has also been clone on single-crystal zinc, but as it 'is not closely related to the present paper it will not be considered. Throughout all the former work, the mechanism of plastic deformation first described by Mark, Polanyi and Schmid has been assumed to hold. This may be said to offer the strongest confirmation of its correctness. Even so, the picture of the process has never been as completely portrayed as is desirable. The first object of the present paper is to describe work that has been done in this field, and which is even yet being carried on, in the hope that a more complete picture may be obtained. Mathewson and Phillips3 have recently described a new mechanism of the deformation of zinc based on their study of large rectangular crystals. One of their conclusions was that deformation produced twinning with a rotation of some of the basal planes into positions 94° removed from their original position; a position almost the same as that of the prismatic planes before twinning. A second conclusion was that fracture occurred along these basal planes in their new position, and, therefore that fractures previously regarded as prismatic were in reality basal. Such findings are of great significance and they raise a question as to the generality of such behavior. Professor Mathewson's opinion is that even the slender cylindrical single crystals behave in the same manner as his large rectangular crystals when strained by simple tension.

Jan 1, 1927

By P. G. Shewmon

A novel technique for determining the surface energy (?) and its derivative with respect to orientation, (?') is described. Essentially it involves the 'floating" of a wedge on the substrate, said wedge being made of a material which is not wet or only slightly wet by the substrate, i. e., as a greased needle "floats" on water. A thermodynamic analysis of a system in which the wedge is supported entirely by surface energy is given. If the original suyface is not at a cusp orientation, the surface tension is directly measurable from the groove angle formed. If the original surface is at a cusp orientation, there may or may not be a groove depending on the relative value of ?' and the weight of the wedge. Experiments primarily on copper and silver showed that sapphire, quartz and refractory metal wedges were wet while graphite wedges were not. The technique was demonstrated to work using graphite wedges, but the results obtained were not as eccurate as those obtained by other workers using the wire-creep experiments. It is concluded that the technique might prove most useful with non-metals where ?' is large and filament creep experiments would be quite difficult. If an absolute value of the surface free energy (?) of a metal is to be determined, the most reliable methods used to date measure an average over the various orientations exposed on a polycrystalline sample. For example, ? for silver, gold, and copper have been measured by determining the force required to just keep a thin wire,' or foil,' specimen from contracting under the influence of ?. Herring 3 has predicted and experiment confirms, that the sensitivity of this method is inversely proportional to the grain size.' Thus it cannot be used to measure ? for a particular orientation by using a foil single crystal or a very coarse-grained specimen. An accurate value if ? for tungsten averaged over a range of orientations has been determined using a field emission technique. The same techniques cannot or have not been used to measure ? for non-metallic solids, and as a result the values available are much less accurate.4 This Paper resents a means of making an absolute determination of ? for a particular surface orientation on any solid, as long as the given surface orientation does not break up into other orientations during an anneal. Experimentally ? is found to vary with orientation and at a few low index orientations it is found to have a cusped minimum, i.e., the derivative of ? with respect to the orientation of the surface changes discontinuously at the low index orientation, see Fig. 1. The slope of a plot of ? vs orientation (herein designated ?') is called the torque on the surface, since it tends to rotate the exposed surface toward the low index orientation, or if the surface is at the cusp orientation it opposes any force tending to rotate the surface out of the low index orientation. The ratio ?'/? has been determined for a few metals, but in cases where this ratio is high there is presently no means of determining either ?'/? or the absolute value of ?' for the orientations present on an annealed surface. The technique discussed herein also provides a means of determining an absolute value of ?' for those orientations which deviate only infinitesimally from a cusp orientation. It should work best on surfaces where ?'/? is large; that is, for cases where no other technique is available for measuring ?'. Aside from trying to learn more about surfaces through measuring ? and ?', the primary reason for wanting values of ? or ?' is to study adsorption. From measurements of the variation of ? for a particular orientation with the concentration of an impurity, one can obtain the number of impurity atoms adsorbed per unit area (Ti) on that orientation using the Gibbs adsorption equation.' where µi is the chemical potential of the adsorbed impurity. Thus, if absolute values of ? could be obtained for the free surface of a given surface orientation as a function of µi, ri could be determined for the given orientation. Furthermore, by equilibrating a grain boundary with the given surface at various values of ki, one could also determine ri for the grain boundary. Similarly Robertson 6 has pointed out that if y is taken to be a continuous function of and µi, then a2 ?/a @a µ2 = a2 ?/a pi a +. Thus, at all orientations away from cusps the following equation holds From a measurement of ?' vs ki, it is thus possible

Jan 1, 1963

By R. W. Heckel, R. L. DeGregorio

The DeHoff method of determining the size distribution of ellipsoid-shaped, second-phase particles has been applied to the spheroidization of cementite in a eutectoid steel. The surface area of Precipitates determined from the various size fractions in the distribution was correlated with surface-area measurements based on the number of intersected interfaces on a random lest line. The precipitate particles were found to be oblate ellipsoids with an axial ratio of about 0.90. The size distributions were found to be log-normal. A method is proposed whereby the shrinkage of small particles and growth of large ones can be determined from the experimental data. The experimental data are compared to previously proposed mathematical models describing diffusion-controlled kinetics and various types of interface-controlled kinetics. The experimental growth and shrinkage rates are considerably slower than those predicted by diffusion-controlled kinetics. The best fit is obtained for a model describing interface-controlled kinetics limited by the rate of formation of cementite at the growing interfaces where the interfacial reaction rate is proportional to the solute thermodynamic activity gradient across the surface. THE subject of spheroidization of second-phase particles has been considered previously by other investigators. Livingston1 has studied the precipitation of the cobalt-rich phase from copper alloys containing 0.7 to 3.2 wt pet Co. His results indicate that the average particle size increases as the cube root of the heat treatment time in accord with diffusion-controlled kinetics.'-' Komatsu and rant' in their studies of the growth of SiO2 in a dispersion-strengthened copper-silica alloy found that the initial growth of SiO2 proceeded by diffusion-controlled growth and later stages were limited by interface-controlled growth. The values of the activation energy obtained for the interface- controlled process led them to the conclusion that the process was limited by the dissociation of SiO2 at the shrinking interface. The transition from diffusion-controlled growth to interface-controlled growth was characterized by a particle size which varied with the heat-treatment temperature. It is also interesting to note that the particle-size distribution as found by Komatsu and Grant exhibits log-normal behavior when replotted on log-probability coordinates. Dromsky, Lenel, and Ansell9 have observed the growth of Al2O3 particles having a mean free path of about 1.5 to 13 µ. Their photomicrographs indicate that the Al2O3 particle sizes were larger than those observed by Komatsu and Grant. Dromsky, Lenel, and Ansell concluded that the Al2O3 coarsened by an interface-controlled growth mechanism limited by the solution of A12O3 at the shrinking interfaces. Bannyh, Modin, and Modin10 have studied the spheroidization of a eutectoid steel (0.83 wt pet C). Their spheroidization (tempering) treatments were carried out in the range from 210o to 700°C for times between 1.5 sec and 20 hr. Measurements of mean particle size as a function of time indicated a cube root of time dependence of size at 700°C, in agreement with previous analyses of diffusion-controlled kinetics.2°7 At lower temperatures, the time dependence was less than the one-third power. It is important to note that, although mathematical models of growth* considering particle-size distribution have been available, measurements of only mean particle size have been carried out. DeHoff11 has presented a quantitative metallography technique which is applicable to the determination of the size distribution of ellipsoids of constant shape. This method is applicable to both oblate and prolate ellipsoids of all ratios of minor to major axis and is based upon an extension of Saltykov's analysis12 of the distribution of spheres of varying size. DeHoff's analysis is based upon measurements of the minor axis of the particles on a random plane of polish in a unit area. This method provides a measure of the number of ellipsoids in various size ranges per unit area. As pointed out by DeHoff, such measurements may be used to obtain surface area and total precipitate volume data. Thus, the accuracy of the distribution analysis may be checked by comparison of the surface and volume

Jan 1, 1965

By T. C. Boberg, R. B. Lantz

This paper presents a method for calculating the producing rate of a well as a function of time following steam stimulation. The calculations have proved valuable in both selecting wells for stimulation and in determining optimum treatment sizes. The heat transfer model accounts for cooling of the oil sand by both vertical and radial conduction. Heat losses for any number of productive sands separated by unproductive rock are calculated for the injection. shut-in and production phases of the cycle. The oil rate increase caused by viscosity reduction due to heating is calculated by steady-state radial flow equations. The response of successive cycles of steam injection can also be calculated with this method. Excellent agreement is shown between calculated and actual field results. Also included are the results of several reservoir and process variable studies. The method is best suited for wells producing from a multiplicity of thin sands where the bulk of the stimulated production comes from the unheated reservoir. The flow equations used neglect gravity drainage and saturation changes within the heated region. INTRODUCTION This paper presents a calculation method which can be used to predict the field performance of the cyclic steam stimulation process. The calculation method enables the engineer to select reservoirs that have favorable characteristics for steam stimulation and permits him to determine how much steam must be injected to achieve favorable stimulation. While the calculation represents a considerable simplification of physical reality and the results are subject to numerous assumptions which must be made about the reservoir, it has been found that realistic calculations can be made of individual well performance following steam injection. The duration of the stimulation effect will depend primarily on the rate at which the heated oil sand cools which, in turn, is determined by the rate at which energy is removed from the formation with the produced fluids and conducted from the heated oil sand to unproductive rock. A complete mathematical solution to this problem is a formidable task, and finite difference techniques would undoubtedly have to be used. The calculation method pre- sented here utilizes analytic solutions of simple related heat transfer and fluid flow problems. The method is sufficiently simplified that it can be used as a hand calculation, although the calculations are somewhat lengthy and laborious. For that reason, the analysis was programmed for an IBM 7044 digital computer. Well responses observed at the Quiriquire field in eastern Venezuela&apos; have been matched using this program after making suitable approximations for reservoir and wellbore conditions. One of the most valuable uses of this calculation method is to assess the effect of reservoir and proc-cess variables on the stimulation response. This paper contains results of several studies made of key reservoir and process parameters. Among the most important of these is the influence of prior wellbore permeability damage. If a well is severely damaged prior to stimulation, a higher stimulation response will be observed than if it is undamaged. If a portion of this damage is removed, a permanent rate improvement will occur. THEORY I)ES(:KJJ&apos;TION OF CALCULATION METHOD The process of cyclic steam stimulation is essentially one of reducing oil viscosity around the wellbore by heating for a limited distance out into the formation through the injection of steam. Suitable modifications of the calculation technique presented here can be made so that stimulation of wells by hot gas injection or in situ combustion can also be calculated. A schematic drawing of the heat transfer and fluid flow considerations included in the calculation method is shown in Fig. 1. In brief, the calculation assumes that the oil sand is uniformly and radially invaded by injected steam. For wells producing from several sands, each sand is assumed to be invaded to the same distance radially. In calculating the radius heated rn energy losses from the wellbore and conduction to impermeable rock adjacent to the producing sands are taken into account. After steam injection is stopped, heat conduction continues and oil sands with r < ra cool as previously unheated shale and oil sand at r > r, begin to warm. The effect of warming of oil sand out beyond r, has little effect on the oil production rate compared to the effect of cooling of the oil sand nearer the wellbore than ra. Thus, in computing the oil production rate, an idealized step function temperature distribution in the reservoir is assumed where the original temperature exists for r > rn and where an average elevated temperature exists for r < rn. The average temperature in the oil sand for the region r < rn is computed as a function of

Jan 1, 1967