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By R. Floyd Farris

Al thorough knowledge of the behavior of cement slurries under elevated temperatures and pressures is necessary in order to solve properly the many problems presented in deep-well cementing operations. In the earlier days of the petroleum industry the depths of wells were shallow as compared to those of today, and the subsurface temperatures and pressures were not of sufficient magnitude to affect seriously the problem of proper control of cement-slurry properties. Today, however, the search for new reserves has extended drilling to such depths that bottom-hole temperatures of more than 200°F. and bottom-hole pressures of 3000 to 5000 lb. are not uncommon. Moreover, there is every indication that within the next few years wells will be drilled to even greater depths and bottom-hole temperatures and pressures will be correspondingly higher than those with which we are concerned today. It has been realized for some time that the behavior of cement slurries at high temperatures and pressures might be very different from that at atmospheric tempera-ture-pressure conditions, but while the temperature effects have been investigated with a reasonable degree of thoroughness, the pressure effects have received little public attention. While the trend toward deeper drilling may make changes in cementing technique and the choice of cements imperative, it was the purpose of this investigation to consider factors having a bearing on the latter, only secondary consideration being ,given, for the present, to details of tech-nique and equipment for oil-field use. More specfically, the purpose of this work was to consider the effect of temperature and pressure upon the behavior of cement slurries. Although it has long been recognized that cements thicken and set rapidly with increasing temperatures, practical methods for the quantitative determination of these effects are comparatively recent developments. In 1935 Silcox and Rule1 presented such a method, describing apparatus designed to measure the consistency-time relationship of cement slurries at relatively high temperatures. The practical importance of this apparatus in furnishing useful data for the evaluation of cement slurries for cementing operations has been emphasized in various technical publications by such writers as E. L. Davis,~ I. F. Bing-ham,3 and J. E. Weiler.4 A paper describing the numerous tests now used to evaluate cements for oil wells was presented in 1939 by W. W. Robinson.= Robinson describes the Consistometer and the Thickening-Time Tester, showing similarity of data from the two devices, and points out that the purpose of each apparatus is to determine the allowable time that a cement may be pumped at a given temperature. At the present time, however, it is believed that results from the Thickening-Time Tester and the Consistometer have not given a

Jan 1, 1941

By B. C. Wonsiewicz, W. W. Wilkening

Following a procedure proposed by Wheeler and Ireland, Plane stress yield loci were constructed from Knoob hardness numbers. Basically, six differently oriented hardness measurements were made on three orthogml surfaces through pure poly crystalline magnesium sheet, a magnesium single crystal, and sheet of the magnesium alloys: Mg + 0.5 pct Th, Mg + 4 pct Li, AZ31B, and EKOO. Hardness loci were found to be in poor agreement at small strains (E < 0.05) with loci established by a more rigorous technique. At larger strains (E - 0.10) the agreement is fair, but at this stage in deformation the conventional locus has lost much of the asymmetry that characterizes these anisotropic materials. Two effects which will lead to distortions in the Khn locus are discussed with reference to the geometry of plastic flow during a hardness test. DETERMINING a material&apos;s resistance to multiaxial loading is of interest not only from a structural design viewpoint but also from that of deformation processing. Unfortunately, the determination of the yield locus, although simple in principle, involves tedious procedures if the results are to be at all rigorous.&apos; The idea, first proposed by Wheeler and 1reland2 of determining the yield locus by means of six Knoop hardness impressions along the principal directions in a material has obvious appeal. It is simple, quick, and should be applicable to very thin sheets. If such a technique could be demonstrated to produce consistently reliable results, it would be of interest to both researcher and designer. Lee, Jabara, and ackofen have compared the yield locus determined by Knoop hardness measurements (the Khn locus) to a locus determined by more rigorous techniques. They found good agreement for two titanium alloys at a plastic strain of about 1 pct. The purpose of this paper is to investigate if the Khn locus construction is a reasonable approximation to the locus of a highly anisotropic material. Examples of such materials are magnesium and magnesium alloys which have severely distorted yield loci which in turn reflect markedly dfferent yield strength in different directions.&apos; In pure magnesium, for example, the yield stress in tension along the transverse direction may be four times the yield stress in compression in the same direction and twice the tensile yield stress in the rolling direction. Predicting such large differences ought to serve as a severe test of the Khn locus construction. EXPERIMENTAL PROCEDURES Samples of rolled sheet, 0.250 in. (6.35 mm) thick, of pure magnesium and four magnesium alloys (Mg experimental materials. The pure magnesium together with the lithium and thorium alloys were those used in the study of Kelley and Hosford. The grain size was ASTM number 4 for the pure magnesium and number 6 for the alloys. HARDNESS TESTING The materials were sectioned along the rolling and transverse planes, mounted in a quick setting resin, and mechanically polished. Most of the hardness tests were performed on a surface prepared by electro-polishing (30 pct nitric acid in methanol at 0°C and 20 v) with the exception of the AZ31B and EK00 alloys which were made directly on a metallographically polished surface. However, subsequent hardness tests on the same sample after heavily electropolishing, revealed essentially the same hardness as before. At least twenty Knoop hardness impressions under a 100-g load were made in each of the six orientations shown in Fig. 1. The average hardness number and standard deviation were then calculated for each orientation. CONVENTIONAL LOCUS CONSTRUCTION Yield loci were constructed using a technique described in detail by Lee and ackofen,&apos; in which the flow stress (stress at a given plastic strain) fixes the coordinates of a point on the locus and measurements of the strain ratio serve to establish the slope of the locus at that point. The loading paths which correspond to uniaxial tension or compression tests establish the four intercepts of the locus with the coordinate axes plus one point on the balanced biaxial tension line Tensile testing was performed along the rolling and transverse (r, t) directions. Samples had a uniform rectangular gage length 1 by 4 by 4 in. (25.4 by 6.35 by 6.35 mm) and were deformed at a strain rate of 3.33 x 104 sec-&apos;. The tests were interrupted periodically to unload the sample and measure the plastic strains by means of X-Y post yield strain gages. Compression tests in the rolling, transverse, and through-thickness (r, f, z) directions were performed on 1/4 in. (6.35 mm) cubes at an initial strain rate of 8.33 x sec-&apos;. Lubrication was provided by 0.002 in. (51 pm) Teflon sheet which was renewed after unloading for micrometer measurements used to calculate the strains.

Jan 1, 1970

By Gilbert Thiessen

THE purposes of this paper are (1) to show that the mineral matter content of coal is satisfactorily represented by the Parr formula; that is, Mineral matter = 1.08 Ash + 0.55 Total sulfur (2) to compare ash-to-mineral-matter ratios with factors by which ash values must be multiplied in order that dry, factor-times-ash-free values shall equal Parr unit coal values; (3) to examine such ash-correction factors and to compare them with similar factors corresponding to certain simplifications or modifications of the Parr formulas and (4) to show that ash-correction factors used for simplification in calculating approximate unit coal calorific values cannot be. correctly used for the conversion of other determined values in an analysis to the unit coal basis, but that each type of calculation requires separate treatment in simplification.

Jan 1, 1934

At Black Lake, Quebec, Lake Asbestos of Quebec Ltd., a wholly-owned subsidiary of American Smelting and Refining Co., has opened a $36-million mining and milling operation which will produce about 100,000 tons of asbestos fiber a year and add 7 pct to the Free World&apos;s supply. The orebody once lay beneath Black Lake, and readying the ore deposit for open pit mining meant removing about 37 million cu yd of overburden- 30 million cu yd by dredging and pumping, and 7 million by power shovels and trucks. The enormous amount of material to be dredged, control of drainage during dredging, the need to cope with drainage problems in the area and to provide for flood control to replace the regulating effect of the lake, posed unusual engineering challenges and required tremendous capital investment.

Jan 1, 1959

By T. D. Mueller

Many investigators have used the response of the "dimensionless aquifer" to a unit pressure drop or a unit fluid-withdrawal volume to calculate the performance of an aquifer in supplying water influx to an oil reservoir. In the past, these response functions have been calculated with the aid of the Laplace transform. With the advent of ultra highspeed digital computers, it becomes practical to solve for the response functions with finite-difference techniques. The computer method also permits extension of the dimensionless-aquifer concept to include the nonhomogeneous aquifer wherein the permeability and other properties vary as a function of the space co-ordinates. This paper gives results of calculating the response functions for a series of nonhomogeneous aquifers. Response functions are presented for both linear and radial aquifers whose thickness, permeability-viscosity ratio and porosity-compressibility vary. These functions are new and should prove useful to the petroleum engineer in analyzing the behavior of nonbomogeneous aquifers. Results are presented in the form of charts that can be easily used by the field engineer. INTRODUCTION Aquifers which surround many oil and gas reservoirs have the ability to supply water influx to such reservoirs as oil and gas are withdrawn. This water influx, called natural water drive, provides one of the most effective driving mechanisms for the production of oil and gas. In producing a reservoir, therefore, it behooves one to make the maximum use of natural water drive. To achieve the maximum use, the reservoir engineer must be able to predict the performance of an aquifer under a variety of production schemes that may be proposed for the reservoir. Unfortunately, the physical properties which dictate aquifer behavior often are known only within limits. Seldom do wells penetrate the porous strata of the aquifer. Even when they do, quantitative information regarding porosity, permeability and water compressibility is seldom available. It is known, however, that the water efflux from most aquifer systems is governed by a single, relatively simple, linear, partial differential equation. Also, the general physical location of the aquifer boundaries often are known. A technique originall proposed by Hurst1 and van Everdingen and Hurst2 has been found useful in analyzing reservoirs in this situation. The idea was later expanded by van Everdingen, Timmerman and McMahan3 to include the mathematical technique of least-squares fitting. This latter method will be referred to as the VTM method. The basic assumptions of the VTM method include the following. 1. The location of the physical boundaries of the aquifer are known. 2. The flow conditions at these physical bound-daries are also known. 3. The aquifer is homogeneous; e.g., thickness, permeability, water compressibility and porosity are constant throughout. In the VTM method, a material balance is made on the fluids entering and leaving the reservoir. In the balance equations, the water-influx term is represented as the product of the water influx from an arbitrarily-selected, dimensionless aquifer system times an unknown conversion number. This balance can be formed as many times as there are data points in the history of the reservoir. Each time, the conversion number can be evaluated. If the reservoir engineer has picked the correct dimensionless aquifer to represent the real aquifer, the conversion number remains constant for all balances that have been made over the history period. If such a situation occurs, the reservoir engineer can then predict the performance of the reservoir for any type of production scheme by using the function associated with that particular dimensionless system and the derived conversion number. These functions will be referred to as the response function of the aquifer. If the aquifer is nonhomogeneous (e.g., if the porosity, permeability, thickness, porosity, or

It has been established that molybdenum sesquisulphide, not molybdenite, is in equilibrium with molybdenum metal and sulphur vapor in the vicinity of 1100°C. The S2 pressure for this system has been obtained using the Knudsen orifice method and the standard free energy for the dissociation of S2. THIS work was undertaken to help in determining the thermodynamic properties of the molybdenum sulphide which is in equilibrium with metallic molybdenum and sulphur vapor in the temperature range 1025" to 1150°C. From the results of MontoroL and of Parravano and Malquori&apos; molybdenite would be expected to be in equilibrium with molybdenum metal, while the results of Guichard indicate that a lower sulphide must be in equilibrium with the metal. Thus it was concluded that the problem warranted reconsideration, especially in view of the suspiciously low temperature independent term for the standard free-energy function for the reaction MoS² Mo + S,. The reaction was calculated and duly noted as being low by Richardson and Jeffes,&apos; using the data of Parravano and Malquori.&apos; Experimental Method The general method used in this investigation is that of the Knudsen orifice method for the determination of equilibrium pressure. The apparatus and technique are similar to those described for the determination of the vapor pressure of silver.% owever, a closed-end McDanel tube instead of fused silica was used to maintain the vacuum, a molybdenum effusion cell with a replaceable lid was employed instead of a silica cell, and a titanium getter maintained at run temperature was used to assure that no oxidation of the molybdenum or molybdenum sulphide was taking place. All runs were made at a residual pressure less than 10-5 mm Hg. The data are given in Table I. Runs 1 through 13 were obtained using molybdenite, analyzed 98.5 pct, from the Molybdenum Corp. of America. The remaining runs were done with a sample from the Climax Molybdenum Corp. which was their grade No. 3 and analyzed 59.87 pct Mo. The weight loss of the cell during heating up and cooling down was subtracted from the total weight loss of the cell during the run. Also, when the tem- perature was changed, the Knudsen cell was placed in the vacuum chamber and heated at temperature for several hours in order to allow the sulphide and the metal to adjust their compositions to the equilibrium values, to desorb or adsorb gases into or from the molybdenum cell itself, and to desorb any water from the molybdenum sulphide or molybdenum powder inside the cell. Water may have been adsorbed inside the cell because, after each run, the top of the cell was removed and the material in the cell was stirred to insure that a layer of molybdenum metal would not build up and obstruct the passage of sulphur vapor into the gas phase. It was established that the molybdenum cell alone decreased in weight an inappreciable amount when heated at the highest run temperature for long periods of time. There are two questions to be answered before the data in Table I can be used to calculate thermodynamic functions: 1—Which molybdenum sulphide is in equilibrium with molybdenum metal and sulphur vapor? 2—What sulphur species are present in the vapor phase? It can be assumed safely that no molybdenum is vaporized, since its vapor pressure is almost negligible at these temperatures. It will be shown subsequently that no sulphide of molybdenum is volatile. Question 1 was answered in the following way: The especially purified molybdenite, obtained from the suppliers mentioned previously, was charged

Jan 1, 1956

By James R. Grage

The lead deposits of Missouri may be divided into three districts, the southwest, middle, and southeast. As too much time would be required to devote a detailed account to each district, only a description of the modes of occurrence of the lead ores in the southeast district will be given. The lead mining region proper of Southeast Missouri is embraced in an area of about twenty-five miles in width by about one hundred in length. The country embraced in this district is very broken, and traversed by ridges from one hundred to three hundred feet; in height, with an occasional knob rising higher. Porphyry forms almost the entire substructure of the region, with here and there outcrops of granite. The crystalline rocks were eroded into ridges and valleys before the deposition of the limestone took place. These porphyries are older than the Silurian limestones, and " belong (according to Pumpelly) to the Archaean (Azoic) formation, of which they may be the youngest member in Missouri. They are the near equivalents, in point of age, to the great iron-bearing rocks of Lake Superior, New Jersey, and Sweden."

By John L. Ham, Robert M. Parke

The melting point of molybdenum is 2625° + 50°C. Heretofore the metal has been considered too refractory to be melted in commercial quantities; hence, it has been formed into rod, wire, and sheet by the methods of powder metallurgy, wherein the temperatures do not exceed 90 per cent of the melting temperature. The manipulation of liquid metals at temperatures of about 2000°C. and above presents some difficult problems in heat transfer, in purification, and in container materials. For metals melting at such high temperatures, it is generally regarded as expedient to circumvent the more common melting and casting process by resorting to powder metallurgy. This circumvention is not accomplished without some penalties, the more notable of which are the relatively high cost of the powder metallurgy method and particularly the size limitations of its product. In an effort to overcome the inherent disadvantages of the powder metallurgy method, especially in respect to the limit of size, a project was begun in 1943 at the Climax Molybdenum Co. laboratory to develop a method of melting and casting molybdenum capable of producing larger bodies of molybdenum than were then obtainable. Later, from Feb. I, 1944, to Aug. 31, 1945, the project was under the supervision of the National Research Committee, Division One. In peacetime, too, there are needs for molybdenurn, which make consideration of another process desirable; for example, large parts for heat engines generally, the omnipresent demand for metal of higher quality and lower cost, and the development of molybdenum-base alloys. This paper describes methods for melting and casting molybdenum, with details of the special process needed to make molybdenum castings ductile, and reports some of the properties of what may be regarded as a new, or at least modified, form of the metal. First Process for Melting and Casting Molybdenum The maintenance of a temperature greater than 2625°C. in a &apos;pace large enough to melt several pounds of molybdenum may involve the loss of heat at a Very considerable rate. For melting molybdenum, therefore, the source of heat must be of high potential and of fairly high power. Evidently, also, the source of heat must not impair the purity of the product. The electric arc operating in vacuum appeared to meet these requirements and was accordingly the first choice as a source of energy. A number of arc devices for melting molybdenum were examined, and several were tried. In the first experiment, a 20-kw., 60-cycle-per-second alternating-current arc was operated between two horizontal and opposed electrodes of molybdenum- In this arrangement the falling droplets of molybdenum solidified below the arc in an irregular mass. This experiment did not produce a useful casting, but the data obtained indicated that

Jan 1, 1947

By John L. Ham, Robert M. Parke

The melting point of molybdenum is 2625° + 50°C. Heretofore the metal has been considered too refractory to be melted in commercial quantities; hence, it has been formed into rod, wire, and sheet by the methods of powder metallurgy, wherein the temperatures do not exceed 90 per cent of the melting temperature. The manipulation of liquid metals at temperatures of about 2000°C. and above presents some difficult problems in heat transfer, in purification, and in container materials. For metals melting at such high temperatures, it is generally regarded as expedient to circumvent the more common melting and casting process by resorting to powder metallurgy. This circumvention is not accomplished without some penalties, the more notable of which are the relatively high cost of the powder metallurgy method and particularly the size limitations of its product. In an effort to overcome the inherent disadvantages of the powder metallurgy method, especially in respect to the limit of size, a project was begun in 1943 at the Climax Molybdenum Co. laboratory to develop a method of melting and casting molybdenum capable of producing larger bodies of molybdenum than were then obtainable. Later, from Feb. I, 1944, to Aug. 31, 1945, the project was under the supervision of the National Research Committee, Division One. In peacetime, too, there are needs for molybdenurn, which make consideration of another process desirable; for example, large parts for heat engines generally, the omnipresent demand for metal of higher quality and lower cost, and the development of molybdenum-base alloys. This paper describes methods for melting and casting molybdenum, with details of the special process needed to make molybdenum castings ductile, and reports some of the properties of what may be regarded as a new, or at least modified, form of the metal. First Process for Melting and Casting Molybdenum The maintenance of a temperature greater than 2625°C. in a &apos;pace large enough to melt several pounds of molybdenum may involve the loss of heat at a Very considerable rate. For melting molybdenum, therefore, the source of heat must be of high potential and of fairly high power. Evidently, also, the source of heat must not impair the purity of the product. The electric arc operating in vacuum appeared to meet these requirements and was accordingly the first choice as a source of energy. A number of arc devices for melting molybdenum were examined, and several were tried. In the first experiment, a 20-kw., 60-cycle-per-second alternating-current arc was operated between two horizontal and opposed electrodes of molybdenum- In this arrangement the falling droplets of molybdenum solidified below the arc in an irregular mass. This experiment did not produce a useful casting, but the data obtained indicated that

Jan 1, 1947

By Henry S. Rawdon

Any laboratory corrosion test, as judged from the practical point of view, is valuable only to the extent that it foretells what will, in all probability, occur in service. Such a test is most properly to be considered as a "pilot test," that is, a test which indicates the direction along which action may be expected to occur rather than as a truly quantitative test which would be expected to tell just how and to what extent the action would proceed. It is generally recognized that laboratory corrosion tests should be chosen with particular reference to the character of service expected for any particular type of metal, so far as it can be foreseen. Even when this requirement has been fulfilled, however, the question whether the actual service behavior of the material is in accordance and general agreement with predictions based upon such laboratory tests is always a pertinent one. The information available in the technical literature bearing on the correlation between the service behavior of metals from the corrosion standpoint, and the results obtained with the same metals in laboratory corrosion tests is very meager, indeed. The results which have been obtained in weather-exposure tests of sheet duralumin which form the body of this discussion are presented here for their bearing on this particular phase of the problem of the corrosion resistance of duralumin. Although the exposure tests described have not been completed, in the sense that all of the tests, in the series initially laid down, have been accomplished, still the general trend shown by the results is so clear that a number of definite conclusions at this stage (subject, of course, to possible modification in the light of later results) are believed to be warranted. The tests reported upon here form one phase of the much broader study of this subject which has been under way for several years in which the National Advisory Committee for Aeronautics, the Bureau of Aeronautics of the Navy Department, the Army Air Corps and the Bureau of Standards have cooperated. Without the very helpful cooperation of the manufacturers in furnishing the

Jan 1, 1929

By Henry S. Rawdon

Any laboratory corrosion test, as judged from the practical point of view, is valuable only to the extent that it foretells what will, in all probability, occur in service. Such a test is most properly to be considered as a "pilot test," that is, a test which indicates the direction along which action may be expected to occur rather than as a truly quantitative test which would be expected to tell just how and to what extent the action would proceed. It is generally recognized that laboratory corrosion tests should be chosen with particular reference to the character of service expected for any particular type of metal, so far as it can be foreseen. Even when this requirement has been fulfilled, however, the question whether the actual service behavior of the material is in accordance and general agreement with predictions based upon such laboratory tests is always a pertinent one. The information available in the technical literature bearing on the correlation between the service behavior of metals from the corrosion standpoint, and the results obtained with the same metals in laboratory corrosion tests is very meager, indeed. The results which have been obtained in weather-exposure tests of sheet duralumin which form the body of this discussion are presented here for their bearing on this particular phase of the problem of the corrosion resistance of duralumin. Although the exposure tests described have not been completed, in the sense that all of the tests, in the series initially laid down, have been accomplished, still the general trend shown by the results is so clear that a number of definite conclusions at this stage (subject, of course, to possible modification in the light of later results) are believed to be warranted. The tests reported upon here form one phase of the much broader study of this subject which has been under way for several years in which the National Advisory Committee for Aeronautics, the Bureau of Aeronautics of the Navy Department, the Army Air Corps and the Bureau of Standards have cooperated. Without the very helpful cooperation of the manufacturers in furnishing the

Jan 1, 1929

By Nicholas J. Grant, Henry Epstein, John Chipman

FOR many years steel producers have been concerned with the presence of hydrogen in steel. Hydrogen dissolved in excess of its solid solubility at the melting point may cause bleeding and gross unsoundness in ingots and castings. In fully-killed steels the hydrogen content which results in these difficulties varies with the alloy content1 and may range from 6 to 12 ppm.* It is also recognized that of heat treatment diminishes rapidly as the size of the part to be treated increases. The time required to remove a specified fraction of the hydrogen present increases as the square of the diameter of the section, making the treatment of large- sizes impractical. In order to prevent bleeding and gross unsound-ness due to hydrogen, and in view of the inadequacy of corrective heat treatment alone to provide optimum properties when hydrogen is present in large sections, efforts to limit the hydrogen content must be taken while the steel is still liquid. The main subject of this paper is a discussion of the factors affecting the hydrogen content of liquid steel in acid and basic open hearth, and basic electric two-slag furnace processing. Literature Survey Because many of the results and observations reported in the literature have a direct bearing on the results obtained in the present research and form part of the basis for conclusions reached, a brief summary of the findings is necessary. Methods for experimental investigation of hydrogen in liquid steel are comparatively new. The first attempts to estimate the hydrogen content of the open hearth bath were by Kalling and Rudberg,6 who devised a method for collecting gases evolved from the boiling bath of a basic open hearth furnace. They found that the gas during the boil generally contained 2 to 3 pct H2. From this and Sieverts&apos;

Jan 1, 1958

By B. C. Riblet

THE president of a large smelting and refining company once telegraphed me that they had acquired extensive mining interests in northern Peru and requested me to inspect their properties as it would be necessary to install a system of aerial tramways between their mines and treatment plant. The concentrator was about 50 mi. from the coast, reached by a fairly good motor road. From the concentrator an aerial tramway would he required, about 6 mi. long, to their first property, a gold and silver mine. The lower terminal of the tramway was at an elevation of 4000 ft. and the mine at an elevation of 9500 ft.

Jan 1, 1937

R. W. Raymond, New York City: In connection with the subject of multiple tuyeres, my attention has been drawn to the practicability of gaining, without the multiplication of tuyeres, the advantages which that measure is intended to secure ; and learning that this had been attempted in the invention of the Gaines radial-discharge or fan-shaped tuyere, I wrote to Messrs. Gustafson Brothers, of Sequachee, Tenn., who manufacture that tugere, for information concerning the invention itself and its performance in practice. To their courtesy I am indebted for most of the facts given below. I present these statements without expressing any personal opinion on the subject (having no personal knowledge of it), for the purpose of bringing this device to the notice of members, and calling forth both criticism and testimony concerning it. Admitting that definite advantages are to be secured by the multiplication of tuyeres, we must still confess that this change involves considerable expense in the increased number of blastpipes, tuyeres, coolers, connections, and pipes for water-circulation. There is, moreover, a serious question involved in the weakening of the furnace-wall by extra perforations. This consideration applies with special force to furnaces already built without reference to such an increase of tuyere-openings. Ledebur, in his Handbuch der Eisenhüttenkunde, says on this point (I translate from the edition of 1893, page 365): "A limit to increase in the number of tuyeres is given, in any case, by the circumstance that the perforation of the wall weakens it; in other words, that there must be left between the tuyeres a mass of masonry sufficient to carry the parts above. In most cases an appropriate number may be secured by giving to the furnace as many openings as there are meters in its circumference at the tuyerelevel. For instance, for a hearth-diameter of 2.5 meters, i.e., a circumference of 7.7 meters, seven or eight openings might be made, of which, however, one would

Jan 1, 1899

In our sessions devoted to geophysical prospecting, the greater part of the time heretofore has been given to the presentation of theoretical subjects or highly technical details by specialists directly engaged in the development and perfection of the various methods. This was necessarily so, for we wanted such information available for the benefit of other workers and for our members who were anxious to gain a reliable understanding of the principles involved, to enable them to form an opinion of the adaptability of this new technique to their special problems. The methods have now been actively applied by many reliable organizations for several years and in this period there has been opportunity for operating mining men, engineers and geologists to appraise them. We therefore felt that it would be desirable at this meeting to give some time to interchange of opinion concerning results from actual cases. Consequently, the Committee on Geophysical Methods of Pros pecting sent out letters of inquiry to numerous mining people, asking for frank statements of opinion based on results from geophysical surveys at their properties. We have received many replies, among which 30 or more are of specific interest. On the whole, the point of view is remarkably uniform. Except for one or two who were, perhaps, a bit irritated, the operating men who have replied consider the methods to be capable of yielding valuable information when suitable conditions exist. Their attitude is definitely one of tolerance and of confidence in the integrity and sincerity of the outstanding workers. There is, however, a very general feeling that the chances of attaining positive and trustworthy results are small unless the work is directed by, or at least carried on with the close cooperation of, a geologist or mining man who is thoroughly familiar with the local geologic and mineralogic conditions and with the relations of the orebodies to rocks and structure. From certain comments, I am inclined to think that some operators are not greatly impressed with the cheapness of the work. Probably they are not attaching much weight to cost per acre, but are thinking primarily of total cost in terms of significant results obtained. It is

Jan 1, 1932

By Y. C. Liu, G. A. Alers

measurements of the anisotropy in Young&apos;s modulus produced in copper by rolling 95 pct reduction in thickness below room temperature have been carried out in order to study the dependence of the texture on rolling temperature. The results clearly show the transition from a copper-type texture to a brass-type texture as the temperature of rolling is lowered. The intermediate textures observed can be described very well as a simple mixture of the two terminal textures. These results cormbined with other texture measurements make possible afresh review of the experimental facts velating to rolling textures in fee metals and, as a consequence, a critical examination of the current theories is presented. PREVIOUS experiments have shown that the transition from the copper- to the brass-type rolling texture is clearly displayed and can be quantitatively analyzed by measurements of the anisotropy of Young&apos;s modulus.&apos; Application of this method to the Cu-Zn alloy system showed that the description of the texture transition as a gradual rotation of the grains from the orientation characteristic of the copper texture to the {110}(112) texture of brass2 was inconsistent with the data. Instead, the data suggested that the texture within the transition region could be described as a simple mixture of the two terminal textures.5 Unfortunately, it was difficult to establish this point conclusively because of the inadequacy of corrections for the composition dependence of the single-crystal elastic constants. Since a rigorous establishment of the nature of this texture transition is essential to our understanding of the formation of rolling textures in fee metals, it is clearly important to undertake an investigation in which the composition dependence of the elastic constants would not enter. A suitable composition-independent texture transition is provided by the well-established variation in the rolling texture of copper with rolling temperature. This temperature-dependent texture transformation has been studied by smallman&apos; in several fee alloys and by Müller5 and others"&apos; in copper. They observed that the texture characteristic of copper rolled at room temperature changed to a brass-type texture when the rolling temperature was lowered to 77°K. Although it is not possible to decide unequivocally from the published pole figures whether or not the 77°K rolling texture of copper is entirely of the brass type,&apos; this complication does not affect the main purpose of the present investigation. In addition to establishing the nature of the texture within the transition region, the modulus data should also provide a determination of the temperature at which the transition occurs as well as the temperature range over which the transition extends. This information when combined with the modulus data on Cu-Zn alloys would then provide a considerable body of new information on textures in fee metals. Since these modulus results and the data obtained from pole-figure studies must be internally consistent, it is appropriate to compile a brief summary of the experimental observations based on all available methods rather than on the pole-figure data alone as has been done in the past. The primary purpose of such a summary would be to yield a more precise definition of the experimental facts on the rolling textures of fee metals, and thus greatly facilitate our evaluation of various proposed theories in this field. The final section of this paper is devoted to this compilation of consistent, experimental facts and their application to the various theories. EXPERIMENTAL PROCEDURE Two 18-lb ingots of cathode copper of 99.99 pct purity were induction-melted under a nitrogen atmosphere in a graphite crucible and chill-cast into a steel mold. The ingots were repeatedly cold-rolled and annealed (I hr at 500°C) into slabs about 1 1/8 in. thick. Blocks 3 1/4 in. wide, 2 1/4 in. long, and 1.000 in. thick were machined from each slab. The rolling schedule used was the same as in the previous investigation1 and the final thickness of the sheet was 0.050 in. with a rolling reduction of thickness of 95 pct instead of 97.5 pct as in the previous work.&apos; The compositions and temperatures of the cold baths used for the low-temperature rolling were as shown in Table I. After each pass the rolled strip was immediately immersed in the cold bath for about 1 min or until the bubbling of the bath had subsided. The modulus data were taken within 2 hr after the rolled strip was warmed to room temperature for the first time, so that effects due to recrystallization were minimized. The modulus specimens were in the shape of flat bars, 3 in. long, 4 in. wide, and 0.050 in. thick, cut with their long dimensions oriented at 15-deg intervals between the rolling direction and the transverse direction. The values of Young&apos;s modulus were deduced from measurements of the frequency at which these long narrow bars were set into longitudinal, resonant vibration as previously described.9 To excite the mechanical vibrations in the specimen, an electromagnetic drive similar to that employed by Thompson and lass" was used. The maximum in the amplitude of

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&apos;s web. This paper will discuss the fundamentals of design of these lines from the economic as well as the engineering view-point, pointing out the effect of the volumes transported, and the load factor at which they are operated, on the unit costs of transportation, as well as the effects on costs of the character of 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

Discussion of the papers of Messrs. Howe and Levy, Burgess, Crowe and Rawdon, and H. M. Howe, presented at the New York Meeting, October, 1913, and printed in Bulletin No. 78, June, 1913, pp. 1075 to 1136. ALFRED STANSFIELD, Montreal, Canada :-In Professor Howe&apos;s paper on the position of Ae3, he shows its industrial importance in determining the temperature to which steel should be heated. for "grain refining." Several years ago I carried out a research on the " burning " of steel and found that while hypo-eutectoid steel should be heated to Ae3, hyper-eutectoid steel that has been very much overheated must be reheated to the curve Sa on the carbon-iron diagram, in order to redissolve the pro-eutectoid cementite and thus, to obtain recrystallization and grain-refining. This treatment was necessarily only partly successful, and I should like to ask whether the conditions of heat treatment for refining overheated high-carbon steels have been ascertained. Speaking of the " Persistence of Solidificational Segregation " Professor Howe quotes an experiment made by Mr. Stead in which a bar of 1.2 per cent. carbon steel was immersed in a large mass of molten blast-furnace slag and allowed to cool with it. The steel was heated above the solidus (curve Aa on the carbon-iron diagram), but below the liquidus (curve AB). A drop of eutectic carbon-iron alloy, rich in carbon, had liquated out and hung below the bar. This agrees exactly with my own observations on the burning of steel, but my interpretation differs somewhat from that of Professor Howe. Professor Howe considers that the fusion of a part of the metal (rich in carbon) shows that the solidificational irregularities of composition had persisted through the rolling and heat treatment of the steel, as otherwise no part of the steel would have been sufficiently fusible to melt. It does not appear to me that such an explanation is necessary. A piece of steel represented in temperature and composition by any point within the area ABa will ultimately resolve itself into a solid phase and a liquid phase in equilibrium with each other. It may appear that if the steel were absolutely uniform no fusion could take place, but the smallest nucleus of high-carbon, fusible alloy would ultimately bring about this separation into liquid and solid phases, by diffusion of the carbon from the solid to the liquid areas. A nucleus sufficient for the purpose might be provided by an area of pro-eutectoid cementite which had not become diffused during the

Jan 12, 1913

By Zavis M. Zavodni, Carl D. Broadbent

During the past 15 years, rock mass structural properties have become acknowledged as the focal point for rock slope design. Re- search into the methods for measuring and incorporating structure into the design effort has taken many directions and has produced a variety of useful techniques. Among the findings at Kennecott has been the realization that structure-controlled instability can be categorized as regressive or progressive depending on the relative geometries of slope and structure and on the strength characteristics of the structures. It was further identified that a failure condition can initiate as regressive and in time become progressive should external stimuli increase or structure characteristics be altered due to extensive displacements. The transition point has been shown to be a useful indicator of the expectable collapse time. This paper defines three fundamental failure types as dictated by structure and offers discussion on the practical value of such a classification to slope design and failure control. Several prominent examples of failures typifying the categories of structure- controlled instability are discussed. An application of f allure prediction based on the regressive-to-progressive transition point is described.

Jan 1, 1983

By William K. Antle

The successful application of ther mo compression lead bonding to semicondtctor or thin-film electronic devices depends on the establishment of the associated parameters. The quality of a thermocompression bond is primarily related to the process temperature and bonding force. A technique using the coelyicient of friction is presented that both reduces the time necessary for determining optimum parameter values and increases the accuracy of the results. Modern theories of the friction process are used to develop mathernatical expressions for shear and tensile bond strengths in terms of friction measurements. A further application of the pararneter-deterlnination technique concerns the measurement of surface contamination that may affect thermocompression bonding. In spite of the extensive use of thermocompression bonding, adequate methods for determining the bonding parameters have not been utilized. The quality of the weld depends on the temperature, force, and time used. There is a definite value or range of values for each parameter which assures an optimum weld. The process now generally used to obtain these values is to make several weld samples at each parametric setting, determine the mean pull strength, and relate the maximum consistent strength to optimum weld conditions. This could involve a very large number of test samples if a thorough search of each parameter were made. Experience and prior knowledge can reduce this number somewhat by limiting the investigation to a range known to contain the correct value, but the time and effort involved are still objectionable. The problems associated with thermocompression bonding of interconnecting leads to semiconductor or thin-film devices can be alleviated by the application of a new technique for establishing the process parameters. Obtaining the correct temperature, force, and duration to assure an optimum bond is accomplished by a simple measurement of the coefficient of friction. This approach increases the accuracy of parameter determination and greatly reduces the time necessary to complete the process. The approach made can be better understood by analyzing the principles of adhesion and friction on which thermocompression bonding depends. When two flat polished surfaces are placed together, the area of actual contact is much less than the apparent area determined by the over-all dimensions of the surface. This is because the microscopic surface is covered with projections which prevent uniform contact. Careful measurements of the electrical resistance across the contacting surfaces indicate the actual area may only be 1100,000 of the apparent area.&apos; Because the actual contact area is small, extremely high pressure results from moderate force. This will produce deformation and plastic flow at contact points of the microscopic projections. The process will terminate in the creation of a large number of minute welds formed at extreme pressure and cold-worked to strong, hard bonds. Load removal will generally result in fracture of most of these microbonds because of the residual elastic stresses, unless the materials are soft. Friction between metals is due to the formation and

Jan 1, 1967