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By C. E. Arnold

A brief description of this installation was included in a recent paper by H. Kenyon Burch.l The purpose of the present paper is to amplify Mr. Burch's description, as it is felt by the writer that the subject merits more than passing attention. In making a comparison between the common method of hoisting men in mine shafts, and elevator practice in high buildings, the former shows to great disadvantage both as regards safety measures and smoothness of operation. It is surprising that in view of the inducements offered, the step of applying the building equipment direct to the mine shaft has not been taken before, as in many respects the conditions of service are similar, and the objects to be attained are identical. Even without doing this, it is certain that safety to life and limb in the usual method of hoisting men underground can be greatly enhanced by the application to the mine hoist of some of the features of the building elevator. In the case under consideration, the elevator cage runs in a vertical, concrete-lined shaft compartment 5 ft. 11 in. by 5 ft. 6 in. (1.8 by 1.68 m.) in section and 585 ft. (178 m.) deep, while the counterweight runs in the pipe and ladder compartment of a twin shaft 102 ft. (31 m.) distant. The section of the division of this compartment occupied by the counterweight measures 2 ft. 4 1/4 in. by 3 ft. 101/2 in. (0.72 by 1.18 m.), and the counterweight is made in the form of a small cage which suffices to carry two men for the purpose of making inspections or repairs in the pipe and ladder way. The hoist is designed to carry a load of 7500 lb. (3401.94 kg.), ex-clusive of the cage, which weighs 7500 lb., at a maximum speed of 800 ft. (243 m.) per minute. It is installed in the main hoist and compressor building about 220 ft. away from the elevator shaft and is driven by a 160-hp. direct-current motor which is served by a 190-hp. motor generator set. A small direct-current generator mounted at the end of the motor generator set furnishes the current for the controller magnets, brake and fields of the hoist motor and generator. The drum, which is 72 in. (1.83 m.) in diameter, is driven through the medium of a single reduction herringbone gear. A Francke flexible coupling connects the

Jan 1, 1918

By Frank F. Poland

TEE purpose of this paper-is to describe a new process for the refining of secondary copper-base metals and a specially designed high-temperature electric-resistor furnace used in the process for the distillation of zinc from these metals. The process was used for the conversion of nickel silver to cupronickel and to recover the zinc content in metallic form. It also proved applicable and economical for the treatment of scrap brass for separating and reclaiming the copper and zinc. The relatively large furnace developed for the distillation of zinc is described in detail, for it made economically possible the direct recovery of metallic zinc from scrap brass, which is a new step in the processing of such material. Considerable interest has been shown in the utilization of the distillation furnace for other metallurgical processes, where it is of advantage to operate in a controlled neutral or reducing atmosphere, or to avoid having the processed metal in contact with refractories other than carbon, or to operate at temperatures between 3000 and 4000°F. PURPOSE OF DEVELOPMENT It was recognized early in the war effort that nickel would become a critical metal, therefore all nickel stock and alloys containing relatively high percentages of nickel were frozen immediately. Among these alloys were considerable quantities of various grades of nickel silver, an alloy containing copper, nickel, zinc, and in some grades lead, also minor amounts of iron, manganese and other constituents. At the time there was no existing plant or process to eliminate the zinc, lead, and minor constituents so as to convert this metal to cupronickel, one of the important alloys needed by the U. S. Navy for condenser parts. Therefore the Bureau of Industrial Conservation of the War Production Board requested the executives of the leading nonferrous metal companies to have their metallurgical staffs study the problem of converting this metal to cupronickel conforming to U. S. Navy Specification 44T40. The composition specified therein is as follows: nickel, 29 to 32 per cent; zinc, 1.00; iron, 0.00 to 0.60; lead, 0.05; tin, 1.20; manganese, 0.00 to 1.00; total of other elements (maximum), 0.50; copper, remainder. The problem in converting these alloys to cupronickel was the elimination of zinc, lead, iron, manganese, and other elements without appreciable loss of nickel to slags or other by-products. Revere Copper and Brass Incorporated, through its Research and Development Department, undertook to solve this problem. A Government-owned plant was built at Rome, N. Y., and there the con- version was successfully made.

Jan 1, 1946

By T. E. Davidson, C. G. Homan

This report deals with a study of the effects of extreme hydrostatic pressure on a polycrystalline material which exhibits a high degree of elastic anisotropy. Metallographically prepared polycrystalline bismuth samples were subjected to pressure levels up to 20,000 atm in a piston type gas-liquid system. The observed structural changes consisted of deformation localized along the grain boundaries, which appears to be a boundary migration phenomena, and widespread slip and cross slip. Subsequent deformation is progressive with increased pressure, and is substantially different in type from the deformation characteristic of uniaxial compression. A large amount of interest has been shown in recent years in the effects of extreme pressure on metals. In this connection, many investigations into the effects of pressure on physical and mechanical properties and reactions have been undertaken. Due primarily to the experimental difficulties involved, there has not been a great deal of study of the structural changes resulting from exposure of metals to extreme pressure. It has been difficult, for instance, to produce a true hydrostatic stress state in many of the extreme pressure devices used, and also to directly examine specimens metallographically before and after pressurization. The results of a preliminary investigation into one of the effects of extreme pressure, and its associated true hydrostatic stress state, on the structure of metals are discussed herein. Metals exhibit varied degrees of anisotropy in their physical and mechanical properties. Significant among the anisotropic properties is the modulus of elasticity, which varies by a factor of as much as three in some of the fcc metals, and by much larger factors in some of the less symmetrical elements. As a result of the variation of the modulus of elasticity with crystallographic direction, shear stresses will be induced in polycrystalline samples under true hydrostatic compression. Depending on several factors, these shear stresses could become of suffi- cient magnitude to cause localized plastic deformation. Presented herein are some of the structural changes observed in polycrystalline bismuth as a result of exposure to hydrostatic pressures of up to 20,000 atm. Although several other materials in both bicrystal and polycrystalline form are also currently under investigation, bismuth was chosen initially, due to its low symmetry and moderately high degree of anisotropy in the elastic properties. The fact that extreme hydrostatic pressure can induce structural changes in some elements in the polycrystalline state is of importance in itself. However, it may also be a factor in many of the other extreme pressure effects. For instance, this localized plastic deformation could substantially lower the recrystallization temperature, thus altering the effects of extreme pressure on this phenomenon. Also, as commented on by ridgman,' the hysteresis in the polymorphic transition of polycrystalline bismuth under extreme pressures could possibly be attributed to structural changes brought about by unequal compressibility. Therefore, to accurately determine the true effects of extreme pressure on metallic substances, one first must determine if any structural changes due to hydrostatic compression are also simultaneously occurring. The purpose of this work has been to determine whether the shear stresses induced by hydrostatic pressure in an anisotropic polycrystalline material, such as bismuth, could reach a magnitude great enough to cause plastic deformation and to study the resultant structural changes and effects. THEORY In a metallic crystal, the elastic properties are dependent upon the crystallographic direction and plane. Depending upon the degree of anisotropy of the elastic properties and other factors, internal shear stresses of sufficient magnitude to cause localized plastic deformation may be induced in polycrystalline material by true hydrostatic compression. The following highly simplified two-dimensional model of two adjacent grains in a polycrystalline aggregate under hydrostatic pressure serves to schematically demonstrate how these shear stresses arise in an anisotropic material.

Jan 1, 1963

By E. C. Bohlen, H. l. Burghoff

THE work reported in this paper was carried out to supplement the existing information concerning directional properties and recrystallization textures of annealed brass sheet and strip. These characteristics are of direct interest when the forming and drawing properties of such material are being considered. Among those who have made contributions in this field are Bass and Glocker;1 Bauer, Göler and Sachs;2 Phillips and Samans;3 Pratt;4 Price;5 Cook;6 Richards;7 Brick;8 and Brick and Williamson.9 These investigators have found, in general, that in brass strip that shows directional variations in properties, tensile strength has a minimum value and elongation has a maximum value at 45° to the rolling direction. The most pronounced directional properties have been found in material given the greatest reductions in rolling followed by high annealing temperatures. Recrystallization texture of brass has been variously reported as (113)[112], (001)[100], and a combination of (110)[115] and traces of the primary rolling texture, (110)[112]. The directional studies have been very informative, but actual tests appear to have been confined to material in its final condition. Tests at intermediate stages have received little attention although previous history of some materials has been partly considered. Perhaps the most comprehensive investigation was made by Cook,6 who studied the directional properties of 70-30 brass strip for which the final and penultimate, or next to the last, anneals and the final reductions were varied. He found that, for any given combination of penultimate anneal and final reduction, the tendency toward the development of directional properties was reduced as the temperature of the final anneal was decreased. In addition to drawing cups and making tensile tests of the finished material at various angles to the rolling direction, he measured the frequency and the angles of twins in grains for several specimens. Plots of his twin counts showed directionality for the materials that produced eared cups. TEST MATERIALS AND EQUIPMENT For this investigation, one commercial heat of 68-32 brass was cast in the form of bars for cold-rolling, 13 ½ in. wide and 1 ½ in. thick. The analysis was as follows: 68.83 per cent copper, 0.04 per cent lead, 0.01 per cent iron, 31.12 per cent zinc (by difference). The bars were so processed to the final thickness, 0.020 in., as to obtain on this thickness all possible combinations of the variables listed below except those involving the sequence of 84 per cent penultimate reduction and 84 per cent final reduction: I. Penultimate reductions of 37 per cent, 50 per cent and 84 per cent; 2. Penultimate anneals at 800°, 900°, 1050° and 1200°F.; 3. Final reductions of 37 per cent, 50 per cent, 69 per cent and 84 per cent;

Jan 1, 1942

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, Jr., Chairman EDGAR RICKARD, Vice-Chairman D. M. LIDDELL, Secretary, 7 Wall St., New York, N. Y. C. A. BOHN, Treasurer JOHN V. N. DORR. LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology, Cambridge,Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY. Chairman OSCAR LACHMUND, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. 0. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD Puget Sound Meets second Saturday of each month SIMON H. ASH, Chairman I. F. LAUCKS, Vice-Chairman CHARLES SIMENSTAD, Secretary-Treasurer, 425 Lyon Bldg., Seattle, Wash. GLENVILLE A. COLLINS JOHN N. POTT

Jan 10, 1917

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman. EDGAR RICHARD, Vice-Chairman. D. M. LIDDELL, Secretary, 7 Wall St., New York, N. Y. C. A. BOHN, Treasurer. JOHN V. N. DORR, LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman. JAMES G. CARLETON, Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Cambridge, Mass., W. E. C. EUSTIS. G. A. PACKARD. Columbia Holds four sessions during year. Annual meeting n September or October. W. H. LINNEY, Chairman. OSCAR LACHMUND, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON, S. SHEDD. Puget Sound Meets second Saturday of each month SIMON H. ASH, Chairman. I. F. LAUCKS, Vice-Chairman. CHARLES SIMENSTAD, Secretary-Treasurer, 425 Lyon Bldg., Seattle, Wash. GLENVILLE A. COLLINS, JOHN N. POTT

Jan 7, 1917

By J. Ruzicka

IN creep testing, material is subjected to a constant load, preferably at a constant temperature, and its rate of deformation is measured. The method of loading can be of various types but in this paper only creep testing under tensile load will be considered. The ordinary tensile test is essentially a comparison test in conditions that frequently bear little or no relation to those under which the test material is to be used in service. The purpose of creep tests is to measure the strength of the test material at slow rates of deformation that more nearly approach the rates realized in service. One purpose of this paper is to illustrate that the creep test, in addi-tion to its value as a service test, is superior to the ordinary tensile test as a sensitive tool for the comparison of certain metals in investigative testing. The other purpose is to describe equipment having distinctive features of design that make it especially suitable for such tests. Representative data obtained with this equipment on a group of rolled zinc-base materials are given. These data are compared with those from practical comparison tests of the creep type on weatherstrip fabri-cated from the same group of materials. The comparison illustrates the value of the fast creep test and of the equipment.

Jan 1, 1937

By J. P. Myers, A. H. Flagg, E. S. Mardock, J. L. P. Campbell, J. M. Terry

The development process for the use of radioactive tracers as a means of locating zones of permeability is discussed. The general techniques for the safe handling of radioactive materials is given as developed by the Lane-Wells Co. and Well Surveys, Inc. The prob1em and. successes with tracers in waterflood systetns, oil and gas injection profiles, fracture sand tracing, squeeze (ement tracing. lost circulution, and cement top localion are discussed and illustrated. INTRODUCTION The exact location of the permeable zones lying within the productive horizon has been a major problem faced by the petroleum engineer for decades, and it has been a problem which has seldom been solved with certainty. Reservoir engineers usually have to incorporate a question mark in their estimates of future reservoir performance because of blanks in the core data. Although the use of radioactivity or electrical logs for the estimation of porosity has been of great assistance in furnishing a record for the reservoir engineer, this application of logging data has not completely solved the problem. In short, the industry needs an in-situ well surveying method which can locate and estimate the permeability of the zones existing within a given pay section. The initial development work with radioactive tracers has been towards filling the need for permeability information. Progress to date permits the location of permeable zones with a qualitative estimate of their relative importance with respect to permeability. The calibration of the method is still incomplete. but present development work on tracer preparations, borehole effect correction factors, and instrument limitations give a promise of quantitative "permeability profiles" in the near future. The development work on the radioactive tracer method discussed here began several years ago in the laboratories of Well Surveys, Inc., in Tulsa. At the outset of this work, three approaches to the problem were visualized as follows: 1. A fluid carrying a soluble, chemically inert, gamma ray emitting isotope is pumped down the borehole and out into the permeable zones of the formation. The greater gamma activity of the permeable zones thus permits them to be differentiated from the impermeable zones which contain no active tracer. It was found difficult to obtain a tracer material which was chemically inert. Absorption to some degree was noted in all experiments. Also, it proved impossible to hold the tracer near the horehole where it could be logged. 2. A fluid carrying a soluble, gamma ray emitting isotope is pumped down the borehole into the permeable formations. In contrast with proposal 1, above. the tracer is chemically active with the fluids and materials in the pore spaces of the permeable zones. The permeable zones are thus indicated by their higher radioactivity level. The main difficulty in this proposal was finding a tracer material which would not be absorbed by shale as well as in the permeable porosity. Very little field work was done with this system. 3. Radioactive particles suspended within the injection fluid are pumped down the well. As the fluid enters the permeable formations, the radioactive particles are filtered out on borehole wall. The permeable zones are differentiated from the impermeable by the gamma ray activity deposited on the formation wall.

Jan 1, 1956

By H. N. Thomson

GENERAL. THE Tooele plant of the International Smelting & Refining Co. is situated at the mouth of Pine canyon, Tooele county, Utah. It is connected with the main line of the San Pedro, Los Angeles & Salt Lake railroad by the Tooele Valley railway, and is about 7 miles from Tooele Junction. Fig. 1 is a general view of the plant. FIG. 1.-TOOELE PLANT OF THE INTERNATIONAL SMELTING & REFINING Co. The copper plant has been in operation since July, 1910, and the first blast furnace at the lead plant was blown in on Feb. 29, 1912. The location of the plant was selected on sloping ground with the idea of using gravity to the fullest extent and thus keeping labor at a minimum. Practically the entire plant is constructed of steel, reinforced concrete, and brick. Bingham ores, both lead and copper, are received over the Utah Consolidated Aerial Tramway. The tram buckets, each containing

Jan 7, 1913

By F. R. Hensel

PuRe silver and silver-lead alloys have been studied as to their suitability for bearing~.' A review of the properties of thallium and the silver-thallium constitutional diagram was made by the author to analyze the possibilities of silver-thallium compositions for antifriction materia1s. t The silver-rich end of the diagram as reported in the literatureg-" was found to be sketchy and it was necessary to carry out corisiderable experimental work to arrive at definite conclusions. Some of the results of this work are reported in this paper. Test Materials In the beginning of the work, only fused alloys were investigated. Later, research Table i.—Composition of Fused Silver-thallium Alloys Tested for Antifriction Properties Percentage Alloy No. of Thallium 1533...................... 0.48 1534.................... 1.06 a31 HT................... 2.04 231....................... 2.10 232 HT................... 3.83 Balance 232....................... 4.07 Silver 233 HT................... 5.86 a33....................... 6.38 a34....................... 9.84 a34 HT................... 10.07 was carried out on electroplating methods and diffusion processes. In preparing the fused alloyst care was taken to exhaust the toxic fumes caused by the thaillium content. The compositions of the series of fused alloys are listed in Table I. The silver-thallium alloys were melted in clay-graphite crucibles and cast into preheated steel molds of 3/4-in, diameter. In the cast condition, they showed a cored structure, as indicated by the micrographs of Figs. I to 3. The etching reagent used was a mixture of 2 grams K2Cr207, 8 C.C. H2S04, and IOO C.C. H20. The cored structure is unsatisfactory for the type of corrosion resistance required for bearing applications, and homogenizing experiments were carried out at various temperatures, the results of which are shown in Figs. 4 through 8. The alloys with a lower thallium concentration, which were heated for 2 hr. at 525°C show an almost completely homogenized solid solution type of structure. With higher thallium concentration, the homogenizing temperature was dropped to 475OC. to eliminate the formation of a liquid phase. It is evident that heating for 2 hr. at this temperature did not iesiilt iii complete elimination of the cored structure. As would be expected, cold-working of the cast structure is an expedient in establishing equilibrium conditions. The fine homogeneous grain structure shown in Fig. 7 corresponds to the cold-worked area under the Rockwell ball penetration when the hardness was taken before heat-treatment. A detailed structural study was made on a cast silver-thallium alloy containing 3.67 per cent thallium. Three micrographs (Figs. 9, 10 and 11) show the transition

Jan 1, 1946

By F. R. Hensel

PuRe silver and silver-lead alloys have been studied as to their suitability for bearing~.' A review of the properties of thallium and the silver-thallium constitutional diagram was made by the author to analyze the possibilities of silver-thallium compositions for antifriction materia1s. t The silver-rich end of the diagram as reported in the literatureg-" was found to be sketchy and it was necessary to carry out corisiderable experimental work to arrive at definite conclusions. Some of the results of this work are reported in this paper. Test Materials In the beginning of the work, only fused alloys were investigated. Later, research Table i.—Composition of Fused Silver-thallium Alloys Tested for Antifriction Properties Percentage Alloy No. of Thallium 1533...................... 0.48 1534.................... 1.06 a31 HT................... 2.04 231....................... 2.10 232 HT................... 3.83 Balance 232....................... 4.07 Silver 233 HT................... 5.86 a33....................... 6.38 a34....................... 9.84 a34 HT................... 10.07 was carried out on electroplating methods and diffusion processes. In preparing the fused alloyst care was taken to exhaust the toxic fumes caused by the thaillium content. The compositions of the series of fused alloys are listed in Table I. The silver-thallium alloys were melted in clay-graphite crucibles and cast into preheated steel molds of 3/4-in, diameter. In the cast condition, they showed a cored structure, as indicated by the micrographs of Figs. I to 3. The etching reagent used was a mixture of 2 grams K2Cr207, 8 C.C. H2S04, and IOO C.C. H20. The cored structure is unsatisfactory for the type of corrosion resistance required for bearing applications, and homogenizing experiments were carried out at various temperatures, the results of which are shown in Figs. 4 through 8. The alloys with a lower thallium concentration, which were heated for 2 hr. at 525°C show an almost completely homogenized solid solution type of structure. With higher thallium concentration, the homogenizing temperature was dropped to 475OC. to eliminate the formation of a liquid phase. It is evident that heating for 2 hr. at this temperature did not iesiilt iii complete elimination of the cored structure. As would be expected, cold-working of the cast structure is an expedient in establishing equilibrium conditions. The fine homogeneous grain structure shown in Fig. 7 corresponds to the cold-worked area under the Rockwell ball penetration when the hardness was taken before heat-treatment. A detailed structural study was made on a cast silver-thallium alloy containing 3.67 per cent thallium. Three micrographs (Figs. 9, 10 and 11) show the transition

Jan 1, 1946

By N. S. Wagner, R. S. Mason

The production of lightweight aggregates in Oregon is a new industry, and, like all new enterprises, it is suffering from growing pains characterized by numerous, small operations some of which flourish for a short time and then cease altogether. Norinally all industrial mineral products are produced in a highly competitive atmosphere. At the present time this condition does not exist to a very marked degree in the state because as yet producers have not saturated the constantly expanding market. This paper has been prepared with the intention of outlining very briefly the current status of the various products now heing used as lightweight aggregates in Oregon. The present piche will surely change, perhaps quite radically within even a short space of time. Lightweight Aggregates Used in the Northwest PUMICE Interest in Oregon pumice is not new. Deposits are abundant. Successful development, however, dates only from 1946. During 1948 a total of nine operations was engaged in full or part-time production of aggregate. The postwar building boom and increased public consciousness regarding the value of insulation are the immediate reasons behind the current development. Just how firmly this production of pumice aggregate may be established is something which cannot be foretold at the present time. Much will depend upon how successfully the pumice aggregate construction already installed stands the test of time. Some fine pumice aggregate products have been made and it seems probable that because of its unique properties a certain demand for pumice aggregate will continue in the future. Fire-proof, rodent-proof, decay-resistant properties supplement the lightness in weight and insulation properties of pumice aggregate products in rendering them particularly ideal for many types of construction. In addition there has been fabrication in the form of reinforced fence posts, street markers, and similar products of a specialized-product nature and these are not to be overlooked in terms of future production. Also pertinent to how soundlj pumice aggregate production is established will be possible future competition with other lightweight aggregates. However, this situation will be governed largely by competitive costs of production and marketing. For its present use, which is almost exclusively limited to the manufacturing of building blocks, the market for Oregon pumice aggregate has been extended from the mining area around Rend and Chemult to points as far distant as San Francisco and Seattle. Naturally enough the bulk of the production goes to the Portland and eastern Oregon consumers. Shipments are made by both rail and truck. Early in 1947 the State Department of Geology and Mineral Industries made a canvass of all pumice producers in the state. The production for 1956 amounted to 26,614 cu yd and was valued at $13,649 at the plants. The United States Bureau of Mines estimates the production for 1947 as 33,240 short tons valued at $111,380. This is roughly 65,000 cu yd. No data are available for the 1948 production but it is understood to exceed that for 1947. The Oregon pumice occurrences originated largely from the eruption of Mount Mazama, the name of the formerly active volcano and the location of Crater Lake. Other lesser volcanoes throughout the area contributed to the present occurrences, however, and it has been estimated by Moore' that the pumice deposits cover an area of some 3500 square miles. This area lies east of Crater Lake between Bend and Klamath Falls and embraces the southern portion of Deschutes County, the northern part of Klamath County, and the northwest corner of Lake County. Thickness of the pumice ranges from thin skims to local thicknesses of as much as 30 to 40 ft. Fragment size also varies greatly. Any attempt to describe the situation by giving screen analyses would be confusing because of the wide variations to be found in all area of this size. The picture can best be summed up by stating that places showing great variations in fragment size can be found if a search for extremes is made. For mining purposes in connection with aggregate production, it call be stated that miles and miles of pumice exist in which the fragrnent sizes range from an inch or so downward. The usual color of the pumice is a light gray to off-white. A typical pumice analysis shows a silica content of about 69 pct, alumina 15 pct, and sodium oxide about 5 pct. Potash, lime, and water are the next three most abundant constituents, running just a little over 2 pct each. Iron oxides are fairly constant at 2.75 pct. Titanium, manganese, magnesium, and phosphorus occur in amounts of less than 1 pct. All of the foregoing substances are combined as a glass exhibiting cellular structure. The weight of crushed but otherwise pit-run (undried) pumice runs around 1100 Ib per cu yd according to figures furnished by various producers. The minimum and maximum weights per cubic yard reported are 1050 and 1400 lb, respectively. The 1400 lb per cu yd pumice contrasts with the pumice from most of the other

Jan 1, 1950

By M. J. Duggin

Structural similarities between the E, X, and iron carbides are illustrated. Experimental evidence regarding phase transformations occurring during ternpering reactions in finely divided carbides, thin-film carbides, and carbides which occur in steels is considered and possible mechanisms for the E — x and x — 9 transformations proposed. HOFER1 has shown that within the appropriate temperature ranges carbon monoxide will react with finely divided a iron to form either iron carbide or x iron carbide. He has shown that at an elevated temperature the E iron carbide will transform to the x iron carbide (Hagg carbide) which, upon further elevation of temperature, will transform to 9 iron carbide (cementite). Jack,2,3 using X-ray diffraction methods, has observed that during the tempering reactions occurring in steel the E iron carbide formed in the first stage of tempering passes into two-dimensional platelets of 0 iron carbide during the second stage of tempering. The three-dimensional form of the 0 carbide is formed during the third stage of tempering. Jack suggested2 that the two-dimensional platelets of 0 carbide could be related to the faulted x iron carbide. Okada and Arata4 investigated a Swedish steel containing 1.05 wt pct C and approximately 1.0 wt pct Mn using permeability measurements at low field strength. A Curie point of 360°C was observed in the quenched steel, which indicated the presence of E iron carbide. On tempering at 400°C the specimen developed a Curie point at 230°C, indicating the presence of x iron carbide, and on tempering at 700°C the specimen developed a Curie point at 190°C which was assigned to 0 iron carbide. The carbides were extracted electro-lytically and the use of X-ray diffraction techniques4r5 indicated the carbide with a Curie point of 230°C to be x iron carbide. The Curie points of the carbides are 10 to 22°C lower than the accepted values which is probably due to the presence of manganese in the carbides, since it has often been observed (e.g., Ref, 6) that a partial substitution of manganese for iron in cementite will lower the Curie point of this carbide. Hofer' summarizes additional evidence of the tempering reactions in steel in which E iron carbide, formed during the first stage of tempering, transforms to x iron carbide during the second stage of tempering. During the third stage of tempering, the x carbide disappears as the 0 carbide is formed. By carburizing thin iron films in a CO gas stream, ~a~akura' has been able to produce the E, X, and 0 iron carbides. He found that below 250°C the E iron carbide was formed; between 250" and 350°C the x iron carbide was formed and above 350°C the 0 iron carbide was formed. He has shown that the E iron carbide transforms to form x iron carbide at 380" to 400°C and that the x ir°n carbide transforms to form the 0 iron carbide at approximately 550" C; both of these phase transformations are irreversible. Hofer' presents a review of evidence to show that the sequence of reactions occurring during tempering processes subsequent to the formation of E iron carbide formed by the direct carburization of finely divided a iron is the same as the sequence of reactions which occur during the tempering processes subsequent to the formation of E iron carbide in steel during the first stage of tempering. It is evident from Nagakura's work that identical tempering reactions are found in thin films of iron which have been carburized to form iron carbide. The purpose of this paper is to discuss the structural similarities between the E, X, and 0 carbides and to suggest a possible mechanism by which regions of the E carbide, formed during the first stage of tempering, may transform to the x carbide during the second stage of tempering. For the finely divided or thin film carbides a mechanism will be proposed for the transformation of the x carbide to the 0 carbide during the third stage of tempering, although it will be suggested that there is evidence that such a transformation may not occur in steels. STRUCTURAL DATA OF THE E, X, AND 0 IRON CARBIDES € Iron Carbide. It is evident from X-ray diffractions and electron diffraction', investigations that the metal atoms in the E iron carbide form an hcp structure with lattice constants ah = 2.752A, ch = 4.3534, using electron diffraction, reports the lattice paramet$rs of the superlattice cell to be a = 4.767A, c = 4.354, c/a = 0.9134. He finds that the carbon atoms occupy the octahedral voids in the metal atom structure so as to form a hexagonal stacking sequence with its basal plane parallel to that of the metal atoms. Considerable long-range disorder occurs in the positioning of the carbon atoms, however, which is in agreement with the possible range of composition Fe2C-Fe3C discussed by Hofer.' Barton and ale" have made X-ray diffraction measurements on a sample of E iron carbide extracted from a catalyst in an organic process. Although there were few reflections recorded on the obtained X-ray powder diffraction pattern, they have proposed that the structure could belong to one of the three possible space groups p3m1, P63/mmc, or Pbcn if one assumed the composition to be Fe2C. Nagakura, using electron diffraction data, suggests a space group of P 6322 for a specimen of c iron carbide of apparent composition Fez.&. x Iron Carbide. The x iron carbide has been studied by Duggin and Hofer" and by Jack and wild,' who

Jan 1, 1969

By John C. Osmond

One of the least known geologic regions in the U.S. is the area now called the Basin and Range Province. It is paradoxical that so little geologic information has been compiled for a province that has yielded billions of dollars worth of metals and is currently producing a small amount of oil. Regional stratigraphic studies of parts of this large territory have been published only recently, and regional structural interpretations of even parts of the province are rare in the literature. This, of course, does great injustice to the earliest workers: Gilbert, Russell, Le Conte, Spur, Louderback, and others, who recognized the area as distinctively different from the rest of North America. Their simplified picture of the structure of the ranges and the province as a whole is the groundwork for present understanding and has never been superseded. Since their early works, however, geologic data from the province has consisted largely of detailed reports of widely scattered mining districts. Each district has been described as though it were an island in an unknown sea.

Jan 3, 1960

By Arthur A. Brant

Let us start back as far as possible, to the beginnings of this universe, some 5 billion or more years ago. This is a time interval that can be crudely underestimated by the moon-earth tidal friction effects that have increased the length of the day by about 1/1000 second per century-from a 5 to 7 hour day to its present 24-and have moved the moon away at 5 inches per year to its present 240,000 miles. The oldest stony meteorites from interplanetary space give an age dating of some 4.6 billion years, approximating the time of formation of our earth. Further, certain stars pulsate, the period of pulsation being related to their absolute brightness. Measuring apparent brightness and comparing, gives the distance away. Thus Hubble and Shapley of Harvard, from 1925 on, were able to show that the universe reached as far as our telescopes could scan. The Doppler shift of the hydrogen red lines could only mean that the nebulae, or galaxies, were moving away at velocities increasing with their distances, by 180 km/ sec velocity increase for every million light year's distance. In short, the universe is expanding like an exploded bomb.

Jan 4, 1964

By Roy C. Kirkman

It is with great pleasure that I read Mr. Howard M. Wells article in the December 1978 issue of MINING ENGINEERING entitled: "Optimization of Mining Engineering Design in Mineral Valuation." Mr. Wells very adequately presents the case and point that there are a great number of variables which must be analyzed during an economic evaluation of an FUND RESOURCE, such as copper or uranium.

Jan 4, 1979

By R. H. Fillnow, D. J. Mac

IT has been demonstrated that alloys in systems structurally analogous to steel undergo reactions during heat treatment similar to those of steel, and yet very little work has been done on such systems, particularly from the standpoint of isothermal transformation. The literature shows that most of the isothermal work has been done on copper-alu-minum alloys.'-3 One paper has been reported on a eutectoid copper-silicon alloy,' and one on iron-nitrogen alloys.' There are no published reports of previous investigations on the isothermal transformation of a eutectoid beryllium bronze. At least two papers have been reported on isothermal age-hardening phenomena in beryllium-copper alloys of lower beryllium content.5,6 No information on eutectoid transformations in this alloy is given in Rimbach's book, "Beryllium." ' This paper reports the results of an investigation on the isothermal transformation characteristics of a eutectoid beryllium bronze. Materials Used and Procedure The eutectoid beryllium bronze used in this investigation was centrifugally cast at the Ampco Metal Co., Inc.. Milwaukee. Wis. A master beryl-lium-copier alloy, purchased from the Brush Beryllium Co., was used to make the beryllium addition to the copper. The alloy was melted under a protective carbon cover and Centrifugally cast into a graphite mold preheated to 920°F. Some trouble with segregation of beryllium in the melt was encountered but was eliminated by violent stirring during melting and pouring. Since very thin .specimens were used for the various heat treatments, only one casting of the four prepared was necessary for the complete isothermal study, thus eliminating any discrepancies caused by a change in composition. The analysis of this casting was 94.035 pct copper and 5.965 pct beryllium. A slight trace of iron was found. The castings were sawed into specimens approximately 3/32 in. in thickness. The specimens were first given an "austenitizing" heat treatment at 788°C, well within the single phase beta region, in a vertical tube furnace. The specimens were then quenched individually into an adjacent molten salt bath and held there for a definite time, after which they were quenched into water at room temperature. Temperature was held to ± 2°C in the salt bath. No homogenizing treatment was given the specimens other than the soak at 788°C. Despite the fact that this was a cast alloy, no evidence of segregation or coring was found in the microstructure of any specimen, either as cast or as heat-treated. Upon completion of the heat treatment, the speci-mens were subjected to metallographic examination

Jan 1, 1951

The Institute is custodian of funds for support of numerous gold medals and prizes and has representatives on boards awarding still others. Details regarding the Institute Awards are given below. The Institute is represented on the boards of the John Fritz Medal, the Hoover Medal and the Washington Award, in connection with the three national societies of Civil, Mechanical and Electrical engineering; and, also, in the case of the Washington Award, with the Western Society of Engineers. The Institute is represented with these four societies on the committee in charge of the Alfred Noble Prize.

Jan 1, 1939

THE slag performs two useful functions. in open-hearth steel-making. First, it is the means of disposal of all the impurities, save carbon, which are removed from the charge materials in refining the steel, so it must be suited to receiving and retaining as much as possible of undesirable elements with minimum loss of iron and useful alloying elements. Second, the slag serves as a buffer between the flame and the bath and transfers oxygen to the metal at a measured pace contrasted with the violent and difficultly controlled oxidation of the bessemer process. At the same time, the slag is a thermal insulator that limits the rate at which heat can be delivered to the metal from the flame, and a heavy slag blanket thereby serves as a brake on production rates. It has been said with justification that the secret of good steel- making is to make a good slag and the steel will take care of itself. In a broad sense, the subject of slag control includes not only the adjustment of the composition of the slag but also of its relative weight in terms of percentage of the metal-bath weight. The slag is made up essentially of: (1) oxides formed by oxidation of silicon, manganese, phosphorus, and iron in the charge, (2) SO2, MnO, MgO, and other oxides charged as such or introduced incidentally with ores or fluxes or by refractory erosion, and (3) lime charged or fed to the heat to neutralize the "acidic" oxides present (SiO2 and P2O5). Obviously, if practically perfect control were possible over the composition of the charge as well as over the oxidation process during the melting period, both slag weight and composition would be very nearly predetermined, and the control problem would be solved. Unfortunately, only a somewhat imperfect control over these factors is possible, so the operator must begin during the lime boil and continue through the refining period to discover and correct departures from the normal pattern of slag development. To do this as the heat progresses, the first helper must be able to make quick estimates of the composition and physical state of develop-

Jan 1, 1951

By Oscar Harder

IT is now just a quarter of a century since Fred W. Taylor§(23) pub-lished his classical paper On the Art of Cutting Metals, describing -his researches in which he, in cooperation with Maunsel White, had developed what is essentially the modern method of heat-treating high-speed steels. Regarding this research, Dr. Sauveur, (22) in his address on Steel Wizards, Past and Present, at the annual banquet of the American Society for Steel Treating in Philadelphia in 1920 said, "The discovery of high-speed steel, or if you prefer, of the treatment imparting high-speed properties to certain steels by Taylor and Maunsel White I am inclined to consider as our one epoch-making contribution to the metallurgy of steel." It was at about that same time (1900) that Taylor exhibited high-speed steels, heat-treated by the improved process, at the World's Exposition in Paris and attracted much attention by showing that the steels would operate at such feeds and speeds that the tips of the tools were visibly red hot. This observation must have started metallurgists to wondering regarding the relative hardness of the various steels at red-heat temperatures. Considerable work has indeed been done in an effort to measure the hardness of high-speed steels and. related materials in the red-heat range, using various methods. . The results, however, have been only partly satisfactory, owing to experimental difficulties. The present investigation had as its immediate inception an address by J. V. Emmons, of the Cleveland Twist Drill Co., to the Columbus Chapter of the American Society for Steel Treating in 1931, in which he deplored the fact that comparatively little was known with regard to the hardness of high-speed steels at elevated temperatures, in spite

Jan 1, 1933