Search Documents

By H. A. Wriedt

Zinc-vapor pressures in equilibrium with bcc solutions of zinc and iron at 703.5", 757", 793", and 900°C were measured by an isopiestic method. Thermody-na?nic properties of zinc in these solutions were derived directly and those of iron with a Gibbs-Duhem integration. Zirzc and iron exhibit large, positive, and moderately temperature-sensitive deviations from ideality. Excess enthalpies and Gibbs energies are positive in the ranges studied. It has been establzshed in relating published phase equilibria to the Gibbs energies of forming solid solutions that positive departures from ideality also exist in the fcc solutions. Tlze stability, as defined by Darken, of the bcc solutions is small but positive at 703.5"C. Its decrease with decreasing temperature indicates that a miscibility gap may exist in the stable or metastable bcc solutions at lower temperatures. The changes of thertnodynanlic properties relatable to changes in magnetic state are minor compared to other changes due to alloying. The accuracy with which the relation between lattice parameter and composition of the bcc solutions is known has been improved. Zinc increases the lattice parameter of a iron by O.ZOZA per unit atom action zinc to at least NZn = 0.25. TO our knowledge, only Ciganl has previously investigated thermodynamic properties of the bcc solutions of the Fe-Zn system. He measured zinc-vapor pressures in the temperature range from about 320" to 360°C by an effusion technique. We have measured the vapor pressures of zinc in equilibrium with bcc solutions of zinc and iron at 703.5", 757", 793", and 900°C by an isopiestic technique. This investigation and the pursuant thermodynamic computations are part of a program for studying several properties of these solid solutions. In the appendix we report a remeasurement of the relation at room temperature between the lattice parameter and zinc content. Related work not reported herein embraces measuring the diffusivity2 of zinc in ferrite at 700" to 900°C and the Curie point temperature3 as functions of composition. EXPERIMENTAL METHOD AND APPARATUS Purified iron at a series of constant temperatures was saturated with zinc at a series of constant zinc-vapor pressures, the range of conditions being so limited that the equilibrated solid solutions were ferri-tic. The equilibration was conducted in long capsules, Fig. 1, that had been evacuated, gettered with titanium, and sealed. The purified iron, part of a vacuum-melted ingot of electrolytic-iron stock (Glidden Co. 1044-grade), had the impurity contents listed in Table I. It was used in the form of millings about 0.001 in. thick. A zinc of 99.999 pct purity (United Mineral and Chemical Corp.) and later one of 99.9999 pct purity (Cominco Products, Inc.) were used, with no observed difference in results. Sufficient zinc was placed in the capsule (separate from the iron and kept at a different temperature) to supply the vapor phase and the iron alloy, while leaving a pool of pure liquid zinc throughout the run. The imposed temperature of the residual zinc pool fixed the vapor pressure of zinc throughout the capsule; condensation was avoided at other locations by making this the lowest temperature in the capsule. Two common complications of nonisothermal systems were, we believe, effectively absent from ours: first, molecular species other than monatomic have no appreciable concentration in zinc vapor at 700" to 900~~: second, the development of zinc-pressure differentials in the capsules was suppressed by use of relatively large-diameter tubing and the absence of diluents in the zinc vapor other than desorbed impurities. The specimens and zinc pool were located at two isothermal zones (each ranging within 1°C over several inches) of a wire-wound, 37-in.-long vertical-tube furnace. The required temperature distribution was achieved by external adjustment of the currents in three electrically isolated windings. The temperatures of the isothermal zones were controlled independently by ther-

Jan 1, 1968

By Joe B. Alford

Founding of the Institute The advance of population and civilization in the U. S. moved through the woodlands of the East, and reached the edge of the great central plains about the middle of the nineteenth century. There the advance paused for almost a generation - ahead were vast reaches of prairie country, uncharted, forbidding, and populated by hostile tribes of the native Indians. The turmoil of the Civil War, and the readjustments following it, further delayed the advance. By about 1870, the Nation was becoming stabilized again, the conflict with the Indians was closing, and the pressure of growth was forcing population to resume its westward movement. In addition to geography, the Nation had another frontier: the development of its immense natural resources. Conditions of the time brought into sharp focus the need for coal, iron, steel, gold, silver, and other minerals. The application of engineering and science was necessary for the production of these minerals and their manufacture into products to meet the needs of a growing nation. The requirements of the time were eloquently expressed in a paper by AIME member Edmund C. Pechin in 1872 : We find, the world over, the most intense activity everywhere displayed in enterprises requiring prodigious quantities of iron. Railways of colossal magnitude are projected. . . . The growing scarcity of timber is compelling the use of iron in buildings; bridges of wonderful size and strength; huge ocean steamships; barges and boats for lake and river traffic; churches; cars, and thousands of minor articles of every shape and size. . . . The time has come when scientific research is to assume its true position - the day of "sheer force and blind stupidity," whose only protection is a high tariff, has gone forever . . . the physicist, the geologist and mineralogist; the chemist, the engineer, are as essential to success as the [blast] furnace itself. . . . There is no merely practical man, no matter how varied may have been his experience, or how long his practice, that will not benefit from the results of scientific investigation. That there is a growing sense of the importance of having thoroughly prepared scientific men in every department of business is evidenced by the institutions [of learning] that are springing up in different quarters, provided with

Jan 1, 1971

By D. T. Goettge, E. L. Robinson

The phase changes occurring in low carbon steel during hot strip mill rolling are shown to be metallurgically significant when related to commonly used temperature control points, particularly finishing and coiling temperatures. In combination, these temperatures are shown to have an important influence on the level and uniformity of hardness, grain size, and carbide characteristics of the finished hot and cold rolled sheets. PRODUCTION of wide flat-rolled products ordinarily requires a number of operations in sequence to prepare the material for shipment to the customer. Most products are tailor-made for specific end uses, with each operation contributing certain properties to the finished material. Since the characteristics imparted to the semifinished product by a given step in processing carry through to the finished product in varying degrees, it is important that the intermediate stages of production of flat-rolled strip be carried out with the same care which characterizes the last or finishing operations. The step of hot strip mill rolling is common to the production of all of the various types of flat-rolled product; therefore, the hot strip rolling is an especially important point at which to recognize and control those variables which have an effect on the surface characteristics and metallurgical properties of the finished product and which influence the ease of conducting subsequent operations. Orders entered at a producing mill usually show an end use or describe an article or part into which the ordered product is to be fabricated. Applying his experience as to the properties necessary in a finished sheet to suit the end use and to perform successfully in the fabrication involved, the metallurgist selects a steel of suitable composition and deoxidation practice, and slabs of appropriate dimensions are produced for rolling on the hot strip mill. At this stage of processing, the metallurgist faces the problem of controlling hot strip mill practice in the light of his diagnosis of the properties necessary to meet the end use, paying due attention to the accompanying problem of producing a strip which can meet processing requirements on subsequent units in the mill. It is the purpose of this paper to describe some of the factors which he must consider in solving these problems and to indicate some of the principles which guide him. Equipment, Physical Requirements of the Strip, and Temperature Measurement The metallurgist must, of course, be familiar with the physical layout of the mill, the temperature-measuring equipment available, and the physical requirements of the hot strip product before he can apply his metallurgical knowledge to the problem; hence, the first section will consist of a brief discussion of these matters. The usual hot strip mill consists of reheating furnaces, five or six roughing stands including a scale-breaker, holding table, and second scalebreaker, six-stand finishing mill, runout table with spray cooling facilities, and coilers. A schematic diagram of a typical layout is shown in Fig. 1. Slab temperatures are primarily a function of heating time and furnace temperatures, while mill speeds, spray practice, drafting practice, available water pressure, temperature of the cooling water, cross sectional dimensions of the strip, coil size, and equipment limitations, either singly or in combination, determine what rolling temperatures are practical on a given hot strip mill unit. Thus, it is possible that a set of temperatures which can be utilized successfully on one mill cannot be used on another. However, adjustments in temperatures and rolling practice can usually be made to develop the desired metallurgical properties. In addition to the metallurgical properties developed through proper temperature control, the hot strip mill must also provide strip with certain physical attributes which may be summarized as follows: Strip Cross Section—The strip contour should conform to a section which will give the best results in the cold reduction operation. This is generally recognized as a strip with 0.001 to 0.003 in. crown or shoulder-to-shoulder convexity depending on width, and freedom from concave, flat, or wedge-shaped cross sections which cause metal buildup in cold reduction. Excessive drop off in thickness at the edges can also be very detrimental in cold reducing to light gages. Gage, Width, and Camber—All of these must be controlled. For example, rundown or increasing thickness from the front to the back of the coil results in nonuniformity in the thickness of hot-rolled sheet product and in added difficulty with gage and welds in cold reduction. Similarly, excessive width variation is the cause of guide trouble and excessive edge scrap at later stages of processing, while excessive camber is the source of a variety of processing troubles. Type of Oxide—Product intended for pickling should have a predominance of the type of oxide most easily removable in sulfuric acid. It is generally recognized that this type is obtained by use of maximum table cooling water and cold coiling

Jan 1, 1957

By J. E. Johnson

Discussion of the paper of Bradley Stoughton, presented at the Cleveland meeting, October, 1912, and printed in Bulletin No. 71, November, 1912, pp. 1245 to 1275. J. E. JOHNSON, JR., Ashland, Wis. :-Is it true that titanium reduces the chill in chilling iron? If so, as I think Mr. Stoughton has stated elsewhere, then I do not see how titanium is beneficial in car-wheel mixtures. One of the most difficult things to do is to get a proper chill and a proper degree of toughness, and the goodness of an iron of the given composition for charcoal-iron purposes is denoted by the chill which it will take as compared with its composition. If titanium reduces that chill, then it does not seem to me as good for car-wheels as its absence would be, and I should like to have it explained what effect titanium has on the chill of a given iron. MR. STOUGHTON : It is true that titanium reduces the chill of iron quite noticeably, yet, at the same time, if I am correctly informed, 90 per cent. of all chilled-iron rolls are made to-day with the titanium treatment, and a great many car-wheels, but one has to make changes in the silicon added and also, if I am correctly informed, in the manganese. The advantage of titanium is that when the proper changes are made, so that we get the same depth of chill with the titanium as we otherwise would without, the chill is much harder than before, and also the body of the roll or wheel is tougher and somewhat stronger, especially under shock. JAMES F. KEMP, New York, N. Y.:-This subject is obviously one of great importance to the iron industry, in that if we call find a method of using titaniferous ores, we will prolong the life of our iron reserves. Fifteen or more years ago, primarily from the study of the ores in the Adirondacks, I be-

Dec 1, 1912

By H. Kazemi

An ideal theoretical model of a naturally fractured reservoir with a uniform fracture distribution, motivated by an earlier model by Warren and Root, has been developed. This model consists of a finite circular reservoir with a centrally located well and two distinct porous regions, referred to as matrix and fracture, respectively. The matrix has high storage, but low flow capacity; the fracture has low storage, but high flow capacity. The flow in the entire reservoir is unsteady state. The results of this study are compared with the results of the earlier models, and it has been concluded that major conclusions of Warren and Root are quite substantial. Furthermore, an attempt has been made to study critically other analytical methods reported in the literature. In general, it may be concluded that the analysis of a naturally fractured reservoir from pressure transient data relies considerably on the degree and the type of heterogeneity of the system; the testing procedure and test facilities are sometimes as important. Nevertheless, under favorable conditions, one should be able to calculate in-situ characteristics of the matrix-fracture system, such as pore-volume ratio, over-all capacity of the formation, total storage capacity of the porous matrix, and some measure of matrix permeability. INTRODUCTION The analysis of flow and buildup tests for obtaining in-situ characteristics of oil and gas reservoirs has received considerable attention in the past decade. Most of the available techniques result in reliable conclusions in macroscopically homogeneous reservoirs or in the homogeneous reservoirs with only certain types of induced and/or inherent heterogeneity (such as wellbore damage, etc.). In general, the greater the degree of heterogeneity, the less the reliability of the information deduced from the pressure transient data. A commonly encountered heterogeneous system is a naturally fractured reservoir where two types of distinct porosities occur in the same formation. The region containing finer pores may have high storage and low flow capacities. This is called the matrix. The remaining region may have high flow capacity with low storage. The latter region is generally the set of interconnecting fractures and fissures of the rock, and for this reason it is called the fracture. Ordinarily, we wish to obtain the permeability and porosity of each region and perhaps the frequency of the fracture distribution in a reservoir. Such information is necessary for reservoir engineering. Other information, such as wellbore damage, will be useful in evaluating possible remedial work for such fields. Few authors have suggested theories to aid in calculating the in-situ characteristics of a naturally fractured reservoir similar to what we have described above. Pollardl suggested that a naturally fractured reservoir contained three distinct regions: a damaged or an improved region surrounding the wellbore, and the two remaining regions the same as described earlier. He suggested that the flow was taking place from the tight matrix into the highly conductive fractures, then into the we wllbore region and finally into the well column. He concluded that the average pressure buildup in each of these distinct regions can be expressed approximately in terms of an exponential decay function of time. He also hypothesized that the decay coefficients for each of these functions were significantly different from each other; consequently, each of these functions became dominant in turn, in the process of pressure buildup. Thus, by a proper graphic plot of the logarithm of wellbore pressure differences vs buildup time, each of these functions could be determined (see Fig. 1). Pollard suggested methods of determining the wellbore damage and fracture volume. Later Pirson and Pirson2 extended

Jan 1, 1970

By A. C. Freeze

The first use of electric punched card accounting machines as an aid in calculating reserves at the Sullivan mine in Kimberly, B.C., was made in January, 1948. At that time their use was limited to totalling individual reserve blocks for the various reserve classes and for calculating total metal content. The immediate objective was to increase speed, improve accuracy, and to effect some savings in labor that could be employed more usefully elsewhere. It was recognized also that the potential for achieving even greater advantages was excellent. The initial experiment proved so successful that it was inevitable that the use of the method would expand. Thus, for the past nine years assay data from core hole and development headings have been processed by these machines and the results integrated with the program of calculating reserves. It was also learned that the machines could store and classify a large amount of other information concerning the mining characteristics of each reserve block in addition to tonnage and metal content. This has proven very useful for the preparation of monthly production reports as well as in long term planning, in forecasting production schedules, and in analysing the results achieved.

Jan 4, 1961

By G. S. Cole

The temperature has been measured ahead of stationary solid-liquid interfaces under conditions approximating luzidirectional heat flow and therefore unidirectional solidification. Natural convection flow patterns may be deduced from the temperature distributions , temperature fluctuations, and shape of the interface. Fluid flow increases with the height and the rate of heat transfev through the interface and this is further manifested by a deviation of the interface from aflat vertical plane. The influence of fluid flow on solute inhomogeneity during alloy crystal growth can be inferred from the observed temperature distributions. A buoyancy force exists in the liquid ahead of a vertical solid-liquid interface, caused by a difference in density between cold fluid near the interface and warmer fluid in the bulk liquid. When the viscous and inertia forces in the melt exceed this buoyancy force, a flow of fluid takes place, termed natural or free thermal convection. Natural convection in purely liquid systems has been extensively studied for many years. 1"u On the other hand, fluid flow during horizontal crystal growth has oniy recently been the subject of experimental investigation."-25 The requirements for horizontal crystal growth differ from other heat flow systems. The small aspect ratio (ratio of height of cold wall to length of fluid) has never been considered. The uniform furnace gradient which supplies heat radially (and not necessarily symmetrically) differs from previous boundary conditions of uniform heat flux at the cold and hot ends. And most important of all an isothermal s/l interface is present which can adjust its shape and position to conform to heat and fluid flow. All of these boundary conditions involve complexities which cannot be readily solved analytically. Preliminary observation has demonstrated the penera1 shape of the natural convective flow pattern in transparent media.20'24'25 The flow is circulatory, directed toward the interface at the surface of the liquid, down and away from the interface at the bottom, and then up at the hot end of the melt. During crystal growth such a flow may interact with the solute boundary layer at the s/l interface to affect solute incorporation.M'1B|28'i!T Evidence has also been presented recently to show that thermal convective flow will affect the structure of ca~tin~s.~~-~~ The rate of heat transfer (conduction plus convection) in a given fluid system is a function of the temperature difference between the hot end of the liquid and the s/l interface and the height of the interface. At the lowest values of these variables* all heat is *It has been shown' that adverse temperature gradients as low as O.OOS°C oer cm are sufficient to cause convection. transferred by conduction. When the temperature difference or interface height are increased, laminar fluid flow commences and heat transport takes place by laminar convection as well as by conduction; turbulent heat transfer takes place at higher values of these variables. In the transition region between laminar and turbulent flow, boundary layer separation takes place; fluctuations in temperature are also noted and increase in amplitude and frequency as turbulence becomes dominant. In this paper, fluid flow patterns in the melt ahead of a stationary interface are deduced from observations of temperature distribution and fluctuations, heat flow rate, and interface shape. The fluid flow ahead of advancing interfaces and the effect of such flow on solute incorporation may be inferred from these measurements on stationary interfaces. Observations during enforced fluid motion will also be considered. EXPERIMENTAL PROCEDURE The metal was contained in a lava boat 10 cm in length, 1+ cm in width, and 2 cm in height, as shown in Fig. 1. A water-cooled, molybdenum block heat-sink is at one end of the boat; surrounding this assembly is a slotted stainless-steel tube noninductively wound with a nichrome heating element. Temperature was measured by 38-gage Chrome1 vs Alumel thermocouples sheathed in 0.05-cm-diam graphite-coated stainless-steel tubing, which were moved longitudinally and vertically through the melt by means of a two-dimensional motorized micrometer stage. In some experiments the thermocouple junction was exposed, but in the majority of experiments the junction was welded to the sheath tip; no significant difference

Jan 1, 1968

By Edgar G. Hill

Much has been written and said recently about the methods used and materials and equipment employed in building the long tubes that criss-cross a great part of the United States, like the pattern of a spider's web. This paper will discuss the fundamentals of design of these lines from the economic as well as the engineering viewpoint, pointing out the effect of the volumes transported, and the load factor, on the unit costs of transportation, as well as the effects on costs of the character 01 the fluids the lines are called upon to handle. Generally speaking, crude-oil pipe lines carry oil from the producing fields to the refineries. Sometimes part of the journey is by pipe line to a coastal point and tank ships are employed for the rest of the trip. The main lines of directional flow of crude oil through pipe lines in the United States are shown on Fig. I, but this, of course, does not always show individual pipe lines. Basic Formula for Flow OF Crude Oil The laws governing the flow of crude oil through pipes are well known. The basic

Jan 1, 1942

By Edgar G. Hill

Much has been written and said recently about the methods used and materials and equipment employed in building the long tubes that criss-cross a great part of the United States, like the pattern of a spider's web. This paper will discuss the fundamentals of design of these lines from the economic as well as the engineering viewpoint, pointing out the effect of the volumes transported, and the load factor, on the unit costs of transportation, as well as the effects on costs of the character 01 the fluids the lines are called upon to handle. Generally speaking, crude-oil pipe lines carry oil from the producing fields to the refineries. Sometimes part of the journey is by pipe line to a coastal point and tank ships are employed for the rest of the trip. The main lines of directional flow of crude oil through pipe lines in the United States are shown on Fig. I, but this, of course, does not always show individual pipe lines. Basic Formula for Flow OF Crude Oil The laws governing the flow of crude oil through pipes are well known. The basic

Jan 1, 1942

By W. R. Hibbard Jr., R. W. Guard, N. G. Ainslie

Evidence is presented that copper-base solid solutions of different solutes having equal grain sizes, no preferred crystal-lographic orientation, equal electron-atom ratios, and, within experimental scatter, identical initial yield strengths, need not have identical stress-strain curves at strains larger than about 0.04. The stress-strain behavior is rationalized in terms of the proposed Suzuki chemical interaction between solute atoms and extended dislocations using what is thought to be a somewhat different means of representing stress-strain data. ALTHOUGH the effect: of alloying element upon the strength characteristics of sold solutions is a subject which has received considerable attention in the past, the exact relationships between the common deformation parameters and certain common variables are not really known in some cases. As a result some of the experiments reported in the literature in which these variables are inadequately controlled lose some of their persuasion regarding underlying principles. Nonetheless, facts are known which bear pointing up: When the true stress, a, and true plastic strain, E, of tensile deformatic~n are plotted on a double logarithmic coordinate system, one may observe a straight-line relationship at strains greater than 0.02. The form of the curve in the linear region is given by a = Ken! where a represents true stress, E, true strain, and K and tn, constants. If the relationship holds, K and m define the flow characteristics of the material being tested. m and K, however, may vary with other parameters. Hollomon found that in a-brass, m is influenced by grain size. French and HibbardZ found in alloys of copper that inverse relationships existed between m and 1) the solute concentration for a given solute, 2) the 0.01 yield strength, and 3) the constantK. Lacy and Gensamer3 observed (du/d~) (= U/Em) to increase with increasing values of K in systems of alloyed ferrites (although with considerable scatter of data which may be attributed to uncontrolled grain size). Brick, Martin, and Angier* deduced in copper-base alloys a straight-line relationship (with some scatter) between the change in the Dph number due to solid-solution strengthening and the change in the Dph number due to work hardening which suggested that copper-base alloys having equal yield strengths might have identical stress-strain curves in the plastic flow regions. French and HibbardZ concluded that the yield strength of copper-base solid solutions is the proper basis for comparing the effects of solute elements. Also, Allen, Schofield, and ate' showed that, within their experimental variation, copper-base alloys of zinc, gallium, germanium, and arsenic having the same electron-atom ratios have the same true-stress true-plastic strain curves. Dorn, Pietrokowsky, and ~ietz' also found that with aluminum-base alloys the stress-strain curves in the flow regions are approximately the same if "equivalent" concentrations of alloying elements are used. Solute valence and lattice parameter distortion were the parameters used to determine equivalency. The present report describes an investigation in which an attempt was made to obtain copper-base solid-solution alloys of four solute elements having within close tolerances equal grain sizes and yield strengths, and to see if the level of yield strength does indeed define the flow curve regardless of solute type. During analysis of the data certain unexpected features of the stress-strain curves became apparent which gave rise to some speculation and are discussed at length in the paragraphs that follow. EXPERIMENTAL PROCEDURES Alloy Preparation—Using the data of French and HibbardZ as a first approximation, four different binary copper-base alioys were designed so as to have the same yield strength. In addition, other alloys were prepared in which the solute aoncentrations varied slightly from those calculated above so as to span a range of yield strengths, see Table L The yield strengths of all alloys prepared except the copper-tin alloys were subsequently found to Lie fairly close to one another. The copper used in the alloys was produced by the American Smelting and Refining Co. and was of very high purity (99.999 pct). The alloy additions and their initial purities are as follows:

Jan 1, 1960

By Stuart Croasdale

Not long ago I was called upon to conduct some experiments on the treatment of ores from the New Cornelia copper mine, Ajo mountains, Arizona, for the Calumet & Arizona Copper Co. The problem was a very interesting one and contained some unusual features. Incidental with this problem was the utilization of a large amount of low-grade pyrite in the Bisbee mines of the company, provided this could be accomplished by any feasible method. The New Cornelia mine is situated 45 miles south of Gila Bend, the nearest railroad point, on the Southern Pacific Railroad. It is about 160 miles, almost due west, from Tucson. This section is one of the most arid in the United States. The normal annual precipitation, as given by the United States Weather Bureau covering a period from 1870 to 1901, is 3 to 5 in. During June and July, 1913, the records kept by the company gave the following results. These are all I have available, but they show the enormous evaporation that can be expected, which may be a factor in leaching operations on a large scale. Temperature, Degrees F. High Low Average June...................... 112 62 84.0 ' July...................... 115 71 87.8 Evaporation June July Concrete tank, inches............ 11.7 10.72 Iron tank, inches.............. 14.8 13.07 Rainfall, inches................ None 0.77 Cloudy days................... None 10.00 Aside from several springs about 10 miles from the property, the nearest known water in quantity at the time these experiments were made was the Gila river at Gila Bend, 45 miles distant. Part of the developinent of the property of course included drilling for water in the valley, which was in progress at the conclusion of my experiments. The ore deposit itself is unusual. It consists of of intrusive plug of monzonite or granite porphyry. Chalcopyrite, bornite, and magnetite are finely disseminated throughout the magma in sufficient quantities to make the greater part of the mass commercial ore to a certain depth.

Jan 1, 1915

By J. H. Craig

As a result of information that the Navy Department was questioning the advisability of raising the maximum allowable exposure temperature for zinc-coated steel parts from 500 to 750 F., it was decided to make a series of high temperature tension tests on several types of uncoated and zinc-coated steels. The objective was to determine at what temperature intergranular penetration of galvanized steel by zinc might take place under conditions of rapidly applied stress and temperature. Tests were conducted in the range from room temperature to 1400 F. In this range, low-carbon and high-carbon steels did not suffer any adverse effects due to zinc coatings. In fact, at 1400 F. the zinc coatings appeared to have a beneficial effect. In stainless steel, the coating had no effect up to 1000 F. Above this temperature, the zinc coating appeared to cause a marked loss in ductility and a less pronounced loss in strength. There was no visible evidence of zinc penetration of the stainless steel structure, but it was assumed that this was the cause of the adverse effect.

Jan 1, 1945

By H. Ries, R. E. Somers

Bodies of pyritic ore in schistose rocks have long been known in different parts of the world. The several occurrences resemble each other in being usually of more or less lenticular shape, inclosed in walls of schist or gneiss, and carrying pyrite, chalcopyrite, and pyrrhotite in varying proportions, as the chief ore minerals. The deposits differ, however, in that sometimes one, sometimes another, of the three sulphides mentioned may predominate. The orebodies in general are more or less closely conformable with the schistosity of the wall rocks, although in cases this may not hold true. The boundaries may or may not be sharp, but in general are fairly distinct. The lenses vary in size, may occur singly, or in groups; in the latter case they may be in line, overlapping, or occasionally parallel. Pinching and swelling of individual lenses is not uncommon. The genesis of these pyritic bodies has provoked much discussion, and they have been variously classed as sedimentary, igneous intrusions, hydrothermal replacements or impregnations, etc. Indeed, in some cases different geologists have most positively assigned widely diverse origins to the same deposit, as in the case of Rio Tintol and Rammels-berg.2 It is true that in the light of modern criteria, we have been able in a few cases to decipher clearly the process of origin and so there seems no. doubt now regarding the genesis of the deposits at Rio Tinto, Spain;3 Rammelsberg, Germany;4 Ducktown, Tenn.;5 southwestern Virginia;=

Jan 1, 1918

By Waldemar Lindgren, Clyde P. Ross

To the miner, as well as to the geologist, the eastern part of Cuba is a most interesting region. Here we find, in contrast to the moderate relief predominating elsewhere in the island, an imposing mountain range, the Sierra Maestra, extending east and west parallel to the coast, its precipitous front facing the blue Caribbean Sea. In a geological sense this range is largely an unknown land, the only well-explored region being that in the vicinity of Santiago. The range also contains the most important mineral deposits of the island. They comprise, first, a series of iron deposits yielding a partly hematitized magnetite with low content of phosphorus; second, a remarkable copper-bearing vein at El Cobre; and third, various manganese deposits. Probably more deposits will be found, for the larger and western part of the range is as yet little explored and its slopes are covered by a thick tropical jungle. The following notes are based on a short visit by the senior author in January and February of 1914 to the mines at Daiquiri, El Cobre, and Mayari. For many courtesies and great assistance he is deeply obliged to Charles F. Rand, President of the Spanish-American Iron CO.; to George W. Pfeiffer, General Manager, and to the several members of his staff. Geological Features of the Sierra Maestra For our knowledge of the geology of the Sierra Maestra we are indebted to reconnaissance work by Fernandez de Castro, R. T. Hill, Mr. C. Hayes, T. W. Vaughan, and A. C. Spencer. The summary by the latter three geologists furnishes the best guide to the region.' The range is undoubtedly outlined by a great east-west dislocation. Its southern slope drops abruptly to the sea, while on the north side a much gentler declivity leads down to the rolling plateau of Tertiary limestone which occupies much of the adjacent part of the island. Viewed

Jan 1, 1916

By A. N. Diehl

IT is the object of this paper (1) to deal with the elements in blast-furnace gas from the standpoint of their importance, and the part they are to play in future consumption, and (2) to give detailed information about the construction and operation of a plant designed among the first in this country for washing gas on a large scale.

Jan 5, 1914

By H. G. Doll

A new electrical logging method. called MicroLaterology is described. whereby the resistivity R of the invaded zone close to the wall of the bore hole is measured. This method essentially utilizes a system of concentric circular electrodes iml,edded in an insulating support which is applied to the wall of the hole. A beam of current of very small diameter is focused horizontally into the formations by means of an automatic control device. and then opens widely at short distance from the wall. with this method, R most often can be recorded directly. except when the mud cake is very thick. in which case a correction is easily provided. The basic role of factor R in the quantitative analysis of electrical logs in terms of fluid saturation and of porosity is explained. The paper is illustrated with field examples. INTRODUCTION In electrical logging. the resistivity of that part of the penneable and porous formations which is invaded by mud filtrate is an important factor in the interpretation. Measurements made with the conventional devices — normal. lateral — and also with improved systems as the Laterolog and induction logging' — are very often more or less affected by the presence of the invaded zone. and the knowledge of the resistivity of this zone is useful in the evaluation of the true resistivity of the beds. which itself is a basic element for the determination of fluid saturation. Moreover. the comparison of the resistivity of the invaded zone with the resistivity of the mud filtrate gives valuable indications on the magnitude of the formation resistivity factor — which in turn is necessary for the quantitative interpretation of the logs. both in terms of fluid saturation and of porosity. On the other hand. it is generally admitted that the invaded zone is not a homogeneous medium separated from the uncon-tamirlated part of the bed hy a well defined cylindrical boundary. but that the fluid distribution—filtrate. connate water. hydrocarbon — and hence. the resistivity. in the invaded zone varies progressively with the distance from the wall of the hole. The term "resistivity of the invaded zone" therefore corre-sponds to an average value which is a function of the distribution of the fluids Inasmuch as the law of this distribution is not exactly known, the resistivity of the invaded zone is not a well defined factor. A much better definition is obtained if the medium under consideration is limited to that part of the formation which is within a short distance from the wall of the hole. It seems likely a within a distance of at least two or three in., most of the fluids in in the pores of tile formation have been displaced by the mud filtrate. The connate water has almost certainly been flushed out. and the oil. if any has generally been reduced to a comparatively small amount. The resistivity witliir~ the radial limit of two to three in. is. therefore. prac.tically constant at an). given level: its value. at least when the proportion of conductive solids in the formation is negligible. is chiefly dependent on the resistivity of the filtrate and on the porosity of the formation, and is affected only to a relatively small degree by the presence of the small amount of residual oil. This part of the formation close to the wall of the hole will he designated in the following as the "flushed zone." a-distinguished from the more general term of "invaded zone'. which relates to the part of the formation extending from the wall out to the distance where the formation is completely uncontaminated. The symbol R,, will he used for the resistivity of the flushed zone. (The notation R is related to the radial distance from the hole. If x designates this distance. xo is the initial value of x, i.e., the value corresponding to the region very close to the wall.) The determination of R is difficult, if not impossible. from logs made with the conventional devices. The long normal and the long lateral are. of course. not suited for this purpose because their radii of investigation are by far too large. The short normal. and the limestone sonde—-after correction for the effect of the hole hole — give resistivity values which corre. spond to materials situated within a comparatively short distance from the hole, but this distance is still several time. as great as the thickness of tire flushed zone. The only value which can be obtained with these devices corresponds to an average resistivity of the invaded zone- — and this only provided the invasion is deep enough, since otherwise the meas "red values would also be affected by the uncontaminated region beyond the invaded zone. It should nevertheless be recalled that despite these limitations. the measurements given by the short normal and or the limestone sonde are always very useful for qualitative interpretation. and also in favorable cases for the qantitative analysis of the logs in terms of saturation and porosity. The MicroLog. which was primarily developed for the detection of permeable beds and for an accurate determination of their boundaries. provides a good approach towards the evaluation of R. In the case of hard formation.. however. The

Jan 1, 1953

By S. Pearson, L. Rotherham

Measurements have been made of the variation of internal friction with temperature for spectroscopically pure silver, and for o series of solid solutions of silver with cadmium, indium, and tin, using a Ke-type torsion pendulum apparatus. Some experiments have also been made to investigate the effect of nonmetallic impurity on grain boundary relaxation in silver. The effect of the alloying elements is to increase the grain boundary viscosity, and to raise the activation energy for grain boundary relaxation from 22,000 cal per mol for pure silver to 43,000 cal per mol for the solid solutions; the same value being obtained, within the limits of experimental error, for all the alloying elements and solute concentrations investigated. Results of the experiments show exactly the same trend as those obtained previously for a similar series of copper solid solutions. They are in agreement with the general theory of grain boundary relaxation developed by Zener and Ke, but do not seem to be in agreement with either of the mechanisms so far put forward to explain grain boundary slip. EXPERIMENTS described in this paper were made as part of an investigation into the effect of alloying elements in substitutional solid solution on grain boundary viscosity, measured by the internal friction method developed by Ke.&apos; The apparatus and experimental procedure have already been described.&apos; Preliminary work was done with spectro-scopically pure silver. Experimental Work Materials Used—All the materials were supplied in the form of % mm diam wire by Messrs. Johnson Matthey and Co. Ltd. The silver and all the alloying elements used were spectroscopically pure. Composition of the alloys is given in Table I. They were all melted and chill cast under the same conditions as the copper alloys. The ingots were rolled to 1/4 in. sq rod with intermediate annealing at 600°C in an atmosphere of cracked ammonia when necessary. These rods were then drawn to wire by standard procedure with intermediate bright anneals at suitable steps in the drawing operations. Specimens from the annealed wires were sectioned longitudinally. mechanically polished, and examined under the microscope. They were then etched and reexamined. Grain sizes were reasonably uniform for all wires, and no traces of a second constituent were observed. The wires were weighed before and after testing so as to measure any loss of the alloying element due to evaporation. The loss was less than the accuracy of measurement—< 0.1 pct of the total weight— for the Ag-In and Ag-Sn alloys, but appreciable loss of weight occurred in the case of the Ag-Cd alloys. The percentage loss is given in Table 11. X-ray diffraction photographs were taken of all thc wires after test to determine whether there was any marked preferred orientation. Results of the examination are given in Table 111. Experiments on Spectroscopically Pure Silver-— Experiments were made on specimens in which the grain diameter was small relative to that of the wire, and on one specimen in which the grains were grown by the usual strain-anneal method to extend across the full diameter of the wire. These large grained specimens will be referred to as single crystal specimens. The wires were annealed for 11/2 hr at 700°C, and experiments were made at two frequencies of vibration, 1.5 and 0.4 vibrations per sec. The variation of internal friction with temperature is shown in Fig. 1. Experiments on a second small grain specimen gave approximately the same results as for the first wire. It will be seen from Fig. 1 that the peak in the curve for the small grained wire, which is presum-

Jan 1, 1957

By W. R. Shimer

(New York Meeting, October, 1913.) THE investigation herein described was carried out for the purpose of studying, both by chemical and metal-lographical means, the extent of over-oxidation of steel that can be accomplished by excessive over-blowing in a Bessemer converter. In addition there are appended some results of basic. open hearth and crucible steels. Remarks on Chemical Methods. The test block used was hemispherical in shape, 4.5 in, in diameter and 2 in. thick. Drillings for analysis were obtained by drilling through the entire solid part of the. block, carefully avoiding all cracks anti blow-holes and mixing these drillings thoroughly. Drillings were carefully examined for scale and the finest were gone over with a microscope to be sure all scale from whatever source had been. removed. Oxygen was determined by the well-known method of Ledebur, modified according to Cushman,1 with, however, the removal of the preheating tube, which was found unnecessary. This method has been found to give concordant results. Blanks run from 0.0003 to 0.0006 g. Duplicate determinations varied not more than 0.001 to 0.003 per cent. It seems to be generally supposed that the hydrogen method gives only that oxygen which is combined with iron. Whether this be true or not, the content of oxygen existing as iron oxide no doubt predominates sufficiently, so that the result obtained is sufficient to indicate whether the steel is over-oxidized or not.

Jan 9, 1913

By H. Groeneveld, C. A. Connally, P. J. Hoenmans, J. J. Justen, W. L. Mason

A miscible displacement pilot using a slug of LPG driven by separator gas was conducted in the Cardiurn reservoir of the Pembina field. The injection pattern was a 10-acre, inverted, isolated five-spot. Upon completion of the LPG-gar phase, an experiment was conducted using a slug of water followed by gas. Calculated performance of the pilot is compared with actual performance. Equations are developed to calculate the distribution of LPG into zones of varying permeability, to estimate the progress of the flood at different times in the various zones and to estimate gas rates after breakthrough. The analysis indicates that permeability stratification was a dominant factor in controlling oil recovery and that oil was completely displaced from the swept pore volume. The results of the pilot indicated that miscible flooding is a practical means of pressure maintenance in this reservoir. The total recovery from the pilot area was good in spite of the early breakthrough of LPG. The effects of stratification were reduced by injecting a slug of water into the partially swept reservoir. INTRODUCTION The Pembina field,&apos; located in Alberta, is the largest oil field in Canada and one of the largest in the North American continent. The reservoir is a stratigraphic trap producing from the Cardium sand. Neither bottom water nor free gas has been found. The recovery of oil by the natural depletion mechanism has been estimated at 12.5 per cent. Pressure maintenance studies of various areas have indicated that the recovery can be increased 21/2 times by water flooding, and a large area of the field is presently under water flood. However, reservoir studies of the North Pembina area indicated that miscible flooding might be competitive with water flooding. A pilot test was conducted to evaluate the performance of a miscible flood. A 10-acre, inverted, isolated, five-spot pattern was selected for the pilot. The pattern area was large enough to minimize wellbore fracturing effects and contained sufficient oil to provide significant working numbers. The performance of each of the four producers could be evaluated individually and compared. In the event of breakthrough in one direction, the effect would be isolated from the other producers. The use of a single injector minimized the volume of LPG required, and, because of the high mobility of gas, one well was sufficient to inject the necessary daily volume to replace the high rate of production. With four producers, the test could be completed in time for results to be evaluated, additional engineering studies to be made and a unit to be formed before the reservoir pressure in the North Pembina area declined below the bubble point. The pilot was located in an area developed on staggered, 80-acre spacing. The injection well was drilled at a regular location, while the four producers were drilled 467-ft north, east, south and west of the injector. Each quadrant and its associated producer were identified according to their direction from the injector— that is, north, east, south or west. The eight surrounding producers on 80-acre spacing were shut in to isolate the pilot area and provide for reservoir pressure observation. The pilot wells were completed using permanent-type completion techniques. After coring, casing was run through the pay section and cemented. Inside 51/2-in. casing, 2 1/2-in. tubing was hung. The wells were perforated opposite the Upper Cardium sand and lightly fractured. Fracturing volumes, rates and pressures were low to minimize the extent of the fractures. The fracturing treatments average 1,000 lb of 20-40 mesh sand in 700 gal of a low fluid-loss sand-carrying agent. Feed rates and wellhead fracturing pressures averaged 5.5 bbl/min at 2,535 psig, respectively. After fracturing, the productivity index was measured in each of the five pilot wells. The average PI of the four producers was 0.41 BOPD/psig drawdown. The measured PI&apos;S were approximately the same as PI&apos;S calculated from core analysis data, indicating that the fracturing treatments were just sufficient to overcome

By S. F. Emmons

The history of the mining region of Custer county has been somewhat peculiar. Although, in the broader features of geological structure, it bears a strong resemblance to its newer and now more famous neighbor, 40 miles to the northward, the Cripple Creek mining district, it has been noted for failures rather than for successful mining ventures. Yet it has a number of mines that have proved themselves to be remarkably rich, and many others that have well-defined veins and very rich ore, though they never have been worked to any great depth. A few of the deposits seemed to the early miner so anomalous in form and manner of occurrence that they were popularly described as " contrary to all geological laws." The region has had several " booms," succeeded by more than usually violent reactions, the latter having proved more permanent than the former. It was, for a long time, the favorite resort of patent-process mongers, and the ground is now strewn with relics of various unsuccessful reduction-plants. Mismanagement, ignorance and disagreements among mine-owners seem to have been quite as responsible for the want of success in the region as the quality of the ores or the form of the deposits. In the early eighties, when the booms had not entirely died out, a division, then under my charge, of the U. S. Geological Survey, undertook an examination of the region for the purpose of making a study of its ore-deposits. The areal survey was carried to completion by Mr. Whitman Cross, but the study of the mines could never be completed for the reason that most of them were closed, for one reason or another, before we had time to visit them. From time to time, one or another of the important mines has been started up again, but it was not

Jan 1, 1897