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By J. P. Kerr, W. H. Cordell

Conditions in the oil and gas industry in Indiana were about the same in 1935 as in 1934. This is especially true of the old Trenton area and the Harrison County area where production was steady and almost no exploration and development took place. The past year has seen an increase in drilling activity and a decrease in oil and gas output in southwestern Indiana. In the state, 224 wells were completed in 1935, of which 48 were oil wells, 61 gas wells, and 115 dry holes. A few of these were old gas wells deepened to oil horizons. Twenty-six wells started during 1935 were not completed by Dec. 31. Approximately one-half the wells drilled were within proven areas. A relatively large number of wildcats, especially in Daviess, Pike and Gibson Counties, were in search of new gas supplies to supplant the diminishing resources in those counties. The decreased production of gas was due largely to the fact that existing supplies declined more rapidly than new fields could be brought on. The Alford field, in Pike County, which produced the bulk of the supply in 1934, was called on to do likewise in 1935, but was unable to respond sufficiently to keep up the yearly production for southwestern Indiana. During the last half of the year, the Oaktown field, Knox County, was connected with one of the principal pipe lines of the state, which helped to keep gas production above an unusual low. The decline in oil production was due almost entirely to proration during the first eight months of the year. The proration affected Daviess, Pike, Gibson, Sullivan and Vigo counties, which produce about three-fourths of the total for the state. After proration was lifted, the wells never quite reached the conditions existing before proration. The average daily production per well in Indiana is less than two barrels. The outstanding development in Indiana in 1935 was the drilling in the Oaktown field immediately before and after the laying of the 6-in. pipe line to the field. Almost without exception the wells came in with an open flow of two to four million cubic feet. At the end of the year, 26 wells were connected to the pipe line. Development of this field will

Jan 1, 1936

By Samuel Taylor

IT is customary for the president of an engineering society, in his annual address, to describe either some engineering problem with which he has beer connected or to review the work of the society during his administration. My first thought, this being the sesquicentennial year of our nation, was to review the advance in coal mining for the past fifty years, during which period I have been more or less intimately con-nected with the bituminous coal industry, and have personally witnessed most of the great changes which have occurred in methods and machinery used in the production of coal, but preparation of the requisite address would take more time than could be spared to prepare it, and its presentation would consume so much time that it .would not be suitable. The new arrangement providing for giving the presi-dent's address at the business meeting makes it more .appropriate to review the work of the Institute during the past year, together with some suggestions which appeal to me as being of advantage to the future wel-fare of the Institute, which I will try to do briefly. The work of the business office has been reviewed in the Secretary's report and it will not be necessary for me to dwell on it. Suffice it to say, it seems to be going along very well. Additional work could be done which would be to the advantage of the Institute, if we had the money with which to defray the necessary ex-pense incident to it, but I will refer to this again later. I would be derelict if I did not refer to the splendid work of the Secretary and the Assistant Secretary. Keeping in touch with all the sections, which number now about 26, and affiliated student societies which number 40, besides special committees, and represent-ing the Institute on various boards, provides work enough to occupy the Secretary's time almost exclu-sively. In addition to this the Secretary and the As-sistant Secretary have the work of editing and publishing the TRANSACTIONS of the Institute; the issuing of the magazine, MINING AND METALLURGY, in the splendid manner in which it goes out to the mem-bership is no light task and I think they should receive the commendation of the membership for this work.

Jan 3, 1927

By Walter S. Weeks

The process of cooling air by allowing it to expand and do work in an engine is well known, but the theory of obtaining cold air by free expansion without the aid of an engine operating with cutoff has been little discussed. Case I If compressed air is allowed to expand to the atmospheric pressure through an orifice in an air line that is supplied by a running compressor, no cooling results except the negligible one due to the JouleThompson effect, which will not be considered in this discussion. The effect of moisture will also be neglected. Symbols P1 Absolute pressure in pipe line, lb. per sq. ft. P3 Atmospheric pressure, lb. per sq. ft. V1 Volume occupied by 1 lb. air in pipe. V3 Volume occupied by 1 lb. air at P3. C, Specific heat of air at constant volume, B.t.u. per lb. per deg. F. C, Specific heat at constant pressure, B.t.u. per lb, per deg. F. T1 Absolute temperature of air in pipe, deg. F. T8 Absolute temperature of air outside after expansion and mixing and coming to rest. j Mechanical equivalent of heat (778 ft. lb.) R Gas constant for air, ft-lb. per deg. F. = 53.3. Formulas Consider 1 lb. of air moving out of a pipe. The air behind it does work on it to the extent of P1V1 ft-lb. This work is really done by the thrust of the piston of the compressor and does not come from any energy that exists in the air in the pipe. The pound of air contains

Jan 1, 1937

By Albert Sauveur

THE senior author of this paper has expressed the belief that when gamma iron transforms into alpha iron on reaching the A3 point, each gamma grain does not change bodily into one or more alpha grains but that the alpha phase forms first at the boundaries and along the crystallographic planes of the austenite grains.1 To quote: On cooling through the point A, at about 900° C., iron passes from the gamma condition to a. new allotropic form generally designated as alpha. This transforma¬tion, however, is not instantaneous. There are good reasons for believing that it begins at the grain boundaries and along the octahedral planes of the crystals and that it progresses until each grain of gamma iron is changed into a grain of alpha iron, the resulting structure being similar to that of gamma iron. Were it possible to retain at room temperature pure iron but partially transformed, it seems probable that a Widmanstättian structure, or rather, as later explained, a martensitic structure would be observed (Fig. 1), consisting of alpha iron at the boundaries and at the octahedral planes, and of a groundmass of gamma iron. In order to confirm, if possible, the accuracy of that view, a number of experiments were conducted. Polished samples of electrolytic iron were heated in a vacuum, maintained in the gamma range for several hours and quenched in different media. It was hoped by such means to produce and retain on the polished surfaces a pattern which would reveal the mechanism of the allotropic transformation. The samples were placed in evacuated quartz tubes, heated to 1000° C. and held 2 hr. at that temperature. The tubes were then immersed in the quenching bath. Iced brine and liquid air were used first. The polyhedral austenitic structure existing at the time of immersion was very clearly revealed (Fig. 2). This is generally ascribed to iron volatilizing at the grain boundaries.

Jan 1, 1929

By R. J. Woody

Design of the most economic continuous counter-current decantation (CCD) circuit is based on selection of the number of stages and the wash volume that will give the minimum summation of the following items: 1) Capital and operating costs of the CCD circuit. 2) Capital and operating costs of the precipitation circuit. 3) Value of the dissolved product lost.

Jan 1, 1959

By Lucien Eaton

VENTILATION in the iron mines of the Lake Superior region in nearly all cases is natural; that is, it is induced by the difference in elevation between different outlets in the mine and by the difference in temperature of the air in the mine and that outside. This difference in temperature is frequently augmented by placing a steampipe in the upcast shaft; but aside from this, artificial aids to ventilation have been rare until - recent years. In some of the older mines, as at the Cliffs Shaft mine at Ishpeming, Mich., in the 80's, fans have been used when there was only one opening to surface, but their use was abandoned as soon as a natural circulation of air started. In recent years, the Newport mine at Ironwood, Mich., was the first to use positive mechanical ventilation. The installation was not large enough, however, to give definite results, reliance being placed largely on natural ventilation. With the coming of warm weather in the spring of 1914, the necessity of positive mechanical ventilation at the Lake mine of the Cleveland-Cliffs Iron Co. at Ishpeming, Mich., became evident. The workings of the Lake mine are under the bed of old Lake Angeline, which was pumped out in 1894, and the mine had been in operation for 6 years prior to that date making a total of 26 years of continuous operation. The total production, up to 1914, amounted to over 8,000,000 tons. The ore was first mined by square-set rooms and pillars, but this was later changed to top slicing and caving. Both methods required the use of large amounts of timber, probably 80,000,000 board feet in all, practically all of which remained in the timber mat. The slow oxidation of this timber was one of the principal causes leading to the installation of mechanical ventilation. The mine was served by only one working shaft, called No. 4, a second outlet being provided by a raise to the surface from the old workings on the south side of the mine. This raise was the "down cast;" but it was very small and the drifts and raises leading to it were too small and crooked to permit an adequate amount of air to enter the mine, especially during the warmer weather. Measure-

Jan 8, 1920

By R. P. Rothwell

IN January last I published in the Engineering and Mining Journal a table giving, with a considerable degree of accuracy, the production of anthracite coal for the year 1874. At that time it was impossible to give any correct estimate of the production of bituminous coal, for the returns I had been able to secure from such distant and scattered districts were not always forwarded punctually, and the work of -obtaining anything like a true estimate of the coal mined in districts from which I was unable to obtain official returns was both laborious and tedious. As will be seen from the detailed reports furnished herewith, I have succeeded in obtaining tolerably accurate returns of 20,093,704 tons; and upon careful revision by numerous well-informed local authorities, my first estimate of the amount of coal not officially returned to me has grown very considerably; indeed, as I get more information on the subject I find that our bituminous coal production greatly exceeds the amount we have been accustomed to hear it placed at, aggregating as it does, 26,465,704 tons. Mr. Andrew Roy, State Inspector of Mines for Ohio, has reported the production of Ohio at 4,168,445 tons, while his first estimates were but 3,820,000 tons; and similarly, in other cases, the more full the returns direct from the mines the more incorrect do I find all previous reports. I am able now to furnish, not an accurate statement, indeed, but by far the most full and reliable one that has yet been published of our coal production. The amount of labor involved in obtaining this admittedly imperfect report has been simply enormous. In the following tabular statement it will be perceived that Pennsylvania produces nearly one-half of all the bituminous coal mined * Since this paper was read fuller reports from some of the States whose production had been "estimated" have modified the figures given. The most serious error is in California, which produces probably 200,000 tons less than these figures. Oregon and Washington territories also yield smaller amounts than here reported; but these reductions are probably fully compensated by fuller reports from other States that were here underestimated. The correct aggregate amount will not vary much from that here given. Early in 1876 I will be able to give a fuller and more accurate report for the year 1875.

Jan 1, 1875

Some years ago the open Hearth Committee of the Institute reached the conclusion that the reading of "set" papers tended to preclude the specific and detailed discussion of specialized problems of current interest to those operating steel plants. As an innovation the Committee distributed in advance of the meeting in May, 1927, a questionnaire containing a list of 27 topics involving operating problems. The subsequent discussion of the questions, participated in by 37 members, was a conspicuous success. Semiannual meetings have been held since; and at the conference of November, 1929, at Chicago, 131 men were present and the minutes comprised a book of 133 printed pages, thereby, indicating the growing value of the conference in the eyes of both the metallurgists themselves and the companies that employed them. With this example in mind, the Directors felt that definite advantages would accrue to a similar conference to be participated in by smelter officials and metallurgists engaged in the operation of copper reverberatory furnaces. The settlement of the Carson litigation, which for several years had virtually stopped public discussion of reverberatory practice, offered an opportune time for launching the scheme. Although the Conference may become largely self-financing in the future, some funds were regarded as necessary to conduct the first meeting. The members of the Rocky Mountain Income Committee, in view of the fact that copper smelting was essentially an activity of the Rocky Mountain area, recommended the project be, in effect, underwritten by the Fund, and the directors approved an appropriation for this purpose. Invitations were extended to high executives of the various-companies interested to send representatives to an initial meeting to be held at Salt Lake City, May 26-27. The response was enthusiastic. Twenty-three metallurgists representing 12 different plants were present to discuss the comprehensive-program relating to construction and operating phases of reverberatory smelting. It was understood that the record was not to be included in the regular publications of the Institute but that it would be prepared for private distribution among the participants and the officials of their companies. That the exchange of views and experience was no less instructive and stimulating than it was frank, full and informal is indicated by the following transcript of the minutes of the meeting.

Jan 1, 1930

By L. D. Tracy

On Aug. 5 and 6,1918, and Mar. 26, 1919, the writer made an investigation of the mine-water neutralizing plant at the Calumet mine of the H. C. Frick Coke Co. The object of this plant is to develop a process of treating the water pumped from the mines so that it may be rendered suitable for use at the power plants of the mines and also at the coke ovens; at the same time, eventually producing a byproduct which will have enough commercial value to provide a sufficient revenue to place the plant on a self-sustaining basis. The Calumet mine is situated in Mt. Pleasant Township, Westmoreland County, Pa., on a branch of the southwest branch of the Pittsburgh Division of the Pennsylvania Railroad. It is about 6 mi. (9 km.) southeast of Greensburg, the county seat of Westmoreland County. The coal, which is the Pittsburg or Connellsville seam, lies at a depth of about 200 ft. (60 m.) and is brought to the surface by means of a shaft. The output of the mine averages 200,000 tons of coal annually, all of which is made into coke, either at the ovens, at the mine, or at byproduct ovens. There are 260 coke ovens at the mine. The continued development of the coal fields of Pennsylvania and the increased use of electric power in the operation of the mines has brought the problem of an increased water supply for the plants to the attention of the coal operators. This is especially true in the Connellsville coking region, where large quantities of water are used in quenching the coke at the ovens. Many of the streams receive the drainage from the mines; and as this water is highly acid and contains sulfur in various forms, some method of treatment is necessary to render it suitable for use at the plants of the mines. With this end in view, the H. C. Prick Coke Co., about 4 years ago, installed at its Calumet mine a plant for experimental purposes, in an endeavor to develop a process that would provide a maximum amount of suitable water at a minimum cost. From a purely technical point of view, the result of these experiments has been encouraging. The company is now endeavoring to place the plant on a commercial basis.

Jan 1, 1922

By Robert W. Hunt

THE memorable features of American history have been making fast during the last century, and notably so since 1860; and they are by no means confined to political or to any one branch of scientific development. Of all the industrial arts, none show a greater change or a mightier progress than the Bessemer manufacture. And this year, while we are celebrating the first centennial of our national life, we can also celebrate the first decennial of American Bessemer practice. While not forgetting or undervaluing what has been done in other countries, I have thought that a brief history of the introduction and development of the Pneumatic or Bessemer process in America would be of interest. In 1863 the Kelly Pneumatic Process Company was formed and an arrangement entered into with William Kelly, who had taken out letters-patent of the United States, Nos. 16,444 ; 17,628, re¬issued as 505; 18,910, dated January 10th, 1857 ; June 23d, 1857; November 3d, 1857; and December 22d, 1857, respectively. This association was composed of the Cambria Iron Company, E. B. Ward, Park Brothers & Co., Lyon, Shorb & Co., Z. S. Durfee, and, later, Chouteau, Harrison & Valle joined the combination. Not satisfied with possessing the control of the Kelly patent, they sent Mr. Z. S. Durfee to England, to secure for this country Mushet's patent on recarburization, No. 17,389, dated May 26th, 1857, the same having been taken out in England on September 22d, 1856. In this Mr. Durfee was successful. Previous to the application of William Kelly for a patent, Henry Bessemer, of England, had taken out patents dated February 12th, 1856, and August 25th, 1856, in this country. Kelly claimed priority in the discovery of the principles of the process, and the Patent-office allowed his claim by granting him his patents. In the autumn of 1862 Mr. Alexander L. Holley, while in England, was impressed with the importance of Mr. Bessemer's inven¬tion, and so fully foresaw its future, that, upon his return to the United States, he induced Messrs. John A. Griswold and John F. Winslow, of Troy, New York, to join him in endeavoring to possess Bessemer's American patents. Mr. Holley returned to England in

Jan 1, 1877

Jan 1, 1913

By L. O. Howard

What was perhaps the first attempt at basic converting in the Southwest was made by the late Charles F. Shelby at Cananea early in 1907, when he removed the acid lining from one of the 8 by 12-ft. barrel-type converters then in use at the reduction works of the Cananea Consolidated Copper Co. and substituted a lining of one course of magnesite brick. In this shell, he blew 21 taps (about 180 tons) of matte to white metal before the brick gave out along the tuyhre line. In every case, the white metal so made was transferred and blown to copper in other converters. The cost of the lining was $700 and Mr. Shelby gave up the experiment as impracticable. No further serious effort to bessemerize copper mattes in a vessel having a more or less permanent lining of basic brick was made by any of the large copper smelters in the Southwest until some months after Messrs. Peirce and Smith had brought the question permanently before the public, and had proved it to be a metallurgical and financial success by their work at Baltimore and Garfield. Early in 1911, the Cananea Consolidated Copper Co. had in operation at its reduction works at Cananea, Mex., several 8 by 12-ft. barrel-type converters lined with magnesite brick which had previously been operating with acid linings. In the 18 months following, these converters produced 50,000 tons of copper. In June, 1912, this company installed the first of its new equipment of six stands of electrically operated 12-ft. Great Palls type converters, and shortly afterward discontinued the use of the smaller shells. In September, 1911, the Consolidated Kansas City Smelting & Refining Co. had installed at its El Paso plant two 10 by 26-ft. Peirce-Smith converters. Later, in March, 1913, one standard Great Falls type converter was added. About the time the Peirce-Smith converters were going in at El Paso, the Calumet & Arizona Mining Co. was experimenting with basic linings in 7-ft. by 10-ft. 6-in. barrel converters at its plant in Douglas, Ariz. These efforts were sufficiently successful to enable the plant to "handle the total output of copper in these small shells until the standard Great Falls converters were substituted in June, .1914.

Jan 1, 1917

By F. E. Steigert, A. H. Geisler

THE permanent magnet alloy comol, which contains 17 pct Mo, 12 pct Co, balance Fe, exhibits a precipitation reaction analogous to that at the iron end of the binary Fe-Mo system. The equilibrium precipitate, (P,), has a structure isomorphous with Fe,Mo, which is rhombohedra1 with parameters a = 8.97A and a = 3038.6&apos; according to the work of Arnfelt and Westgren.&apos; In the ternary alloy the parameters are a = 8.87A and a = 31°0.5&apos;. Oscillating crystal patterns of a single matrix crystal, M, in which P, was precipitated by slow cooling from 1300°C, showed that the orientation relationship of the two lattices is as follows: (110)P3 // (110)* (111)p3 // (110)m There are crystallites of P, in 12 different orientations in a single crystal of the parent solid solution. Microscopic examination shows that the crystallites are generally plate-like with their lateral dimensions parallel to (110) matrix planes. When precipitation in a supersaturated alloy quenched from 1300°C progressed isothermally at temperatures between 600" to 800°C, the evolution of the P, structure could be traced. Diffuse diffraction effects in Laue patterns provided early evidence of the precipitation process. Analyses of these by a previously described technique2 showed that they corresponded to rod-like elements parallel to <110> matrix directions in reciprocal space. With further aging to promote growth of the precipitate, the rod-like elements contracted to points in reciprocal space for normal Bragg reflection from the precipitate as shown by the left diagram in Fig. 1. Thus the diffuse scattering was attributed to the small thickness of the plate-like particles which was inadequate for sharp diffraction. When the precipitate particles were first thick enough to give normal diffraction their structure was different from that of the equilibrium precipitate, P,. The first structure, P1, presumably is a coherent transition struc-

Jan 1, 1952

By Lawrence A. Soltis

Senior engineering or executive management positions are filled by engineers who are evaluated on their performance, knowledge, skill, and maturity. Not only is technical expertise required but a knowledge of sales and marketing, finance, law, industrial relations, and public affairs is necessary. The University of Wisconsin-Extension offers an innovative post-baccalaureate degree program blending technical and professional subjects the Professional Development Degree in engineering (PDD)-designed to bring various opportunities for learn-

Jan 4, 1978

By J. W. Stewart

THE aim of this paper is to point out the various ways in which design is taught in standard four-year mining engineering curricula in American colleges and universities; to discuss the reasons apparently justifying the great diversity of procedure that exists along this line; and to indicate possible solutions to the difficulties now attending the teaching of design. A study was made of typical four-year mining engineering curricula in 15 colleges and universities of the United States (Table I). Great diversity in content of the various design courses, if taught as described, became apparent immediately. It appeared that it might be both interesting and instructive if the cause for this colorful variety could be found. Was the cause local mining conditions, departmental individuality, or actual necessity? Study of the school catalogues revealed that the various design courses could be classified into two fairly distinct types; namely, (I) those dealing with mine equipment or structures, and (2) those dealing with underground layout of mine workings. It seemed reasonable to label the first type of course "mining design" and the second type "mine design." Some such distinction must have been in the minds of mining educators, for we find both names (i.e., mine design and mining design) used to designate the design courses included in the various mining curricula. Unhappily, the name and the apparent content of such courses do not, in all instances, conform to the classification made here, although in most instances such conformation does obtain (Table I), It is possible that in the exceptional case the method of teaching a design course, and consequently the content of it, may have been changed at some time without change in the name of the course. Apparently only 3 of the I5 schools made an effort to cover both types of design in their curricula (Table I). Two other schools did not list or describe any course of study that could with certainty be taken as a design course. Of the remaining 10 schools, 9 gave a mining-design type of course and one gave a strictly mine-design type. Obviously, the preponderance of design courses afforded are of the mining-design type. Why? To answer this question, it is necessary to make a study of the prerequisites for the two types of design courses taught. In all schools the design courses were taught in the senior year; in eight, design was taught throughout both semesters; in two, it was taught during the first semester only; and in three it was taught during the second semester only. Consequently, excepting the last three cases noted, it is obvious that all prerequisites for a design course should be completed by the end of the junior year. PREREQUISITES What are the probable prerequisites for the different kinds of design courses as they appear to be taught? Let us take first the case of the mine-design type of course, having to do with layout of underground workings. Here it would seem that logical

Jan 1, 1941

By E. M. Murphy

(Presented by invitation at a meeting of the Spokane Local Section of the Institute, Feb. 17, 1912.) EIGHT years ago the Hecla mine, a lead-silver producer, situated at Burke, Idaho, was producing ore from but two levels, the 300- and the 600-ft. All hoisting was done with a 12- by 16-in. slide-valve, double-reel, hoist. The hoist was being worked to its capacity and was unsuitable for hoisting from greater depths. As the work of opening a new level was about to be started, it became necessary to remodel the then-existing equipment or install a new hoist. The recent advent of electricity from Spokane had made available a cheaper power than steam. By a series of tests conducted throughout the Coeur d&apos;Alène district, it was found that it cost $109 per year to generate a horse-power with steam. Electric power was to be had for $50 a horse-power per year. It was decided to substitute for the engines a motor-drive, of sufficient capacity to operate from the 900-ft. level, and ultimately install an entirely new hoist. After disconnecting the engines, installing a new shaft, and making a few minor changes, a 300-h-p., 2,300-volt, 514-rev. per min., variable-speed motor of the induction type was geared to the reel-shaft. The reels were supplied with 3/8 by 4-in. flat rope, and the duty of the hoist was about as follows: Cage, 1,700; ore, 2,600; car, 1,400; rope, 2,250; total, 7,950 pounds. The Bristol ammeter chart, Fig. 1, shows the combined current-consumption of the hoist- and mine-motors. The large intermittent load is clearly shown ; this produced harmful fluctuations in the voltage of the long, lightly-loaded, 60,000-volt transmission-line from Spokane to the Coeur d&apos;Alènes. The power company received no compensation for the increased cost of producing power for this intermittent or fluctuating load. In order to protect its system from similar excessive

Sep 1, 1912

By F. F. ESPIE

Giving the keynote address in the final session of a conference dealing with closely related topics has a disadvantage in that much of what can be said has been said. It also has an advantage, however, because it presents the speaker with the opportunity to integrate and analyse the material presented by the various speakers. I would like to look to the near future in Australia and the United States of America, to the risks, problem areas, and changes of a rapidly evolving post-industrial era-an era we are beginning to experience where industry no longer &apos;calls the tune&apos;. We miners have been quick to point out and emphasize, that ours is a &apos;high-risk&apos; industry in the world of business and commerce. Yet, clearly those who have survived, and been successful, have learned to anticipate and cope with risk and change. This ability has been a &apos;distinguishing feature of the industry&apos;s leaders who, in market studies and commodity selection, exploration and development, mine planning, metallurgical pro- cessing, and general administration and operation 1. identify areas-of risk or inevitable change, 2. analyse, test and quantify those factors of risk or change, and 3. design methods, systems, equipment to eliminate, moderate, or control or economically compensate for predicted risks or changes.

Jan 1, 1978

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 B. J. Nelson, F. N. Rhinos

Studies upon the rates of oxidation of copper alloys containing small quantities of the alloying elementsl,2 have shown that steady growth of the scales at predictable rates is limited to a small concentration range and to oxidation at temperatures above 600°C., whereas unpredictable and erratic oxidation behavior is found with alloys containing larger additions and at low temperatures. The latter effect appears to be associated with modifications in the geometric disposition of the oxides. At low concentrations of the baser elements in copper, simple oxidation behavior is typified by the formation of two distinguishable zones of oxidation: (I) a subscale composed of discrete particles of the oxide of the alloying element embedded in substantially pure copper and (2) an external scale composed of cuprous oxide (with a very thin layer of cupric oxide on the outside) containing particles of the alloying element distributed throughout, but most profusely near the metal surface (see Fig. 2, top). Where this type of structure obtains, the process of oxidation is believed to be implemented, and its rate controlled, by the diffusion of the reacting elements through a&apos; continuous matrix phase; i.e., through the alpha (metallic) phase of the subscale and alloy and through the cuprous oxide of the external scale. Copper is presumed to diffuse outward through the cuprous oxide layer to the external surface, where it reacts to form more cuprous oxide.3 Oxygen is delivered at the oxide-metal interface in the form of cuprous oxide, which may either react with the alloying element to deposit its oxide at the inner limit of the external scale or dissolve in the pure copper that remains at the surface of the metal after it has become depleted in its oxidiza-ble alloying elements. Both oxygen and the alloying element are pictured as diffusing through the metal, the oxygen inward and the alloying element outward. Where the two diffusion streams meet in sufficient concentration the oxide of the subscale is precipitated. If the oxygen pressure in the surrounding atmosphere is just below the pressure necessary to maintain cuprous oxide undecomposed, no cuprous oxide can be formed; some of the oxide of the alloying element may form upon the external surface, if its decomposition pressure is below that of cuprous oxide, and a normal sub-scale appears. This condition is achieved experimentally by enclosing the alloy with cuprous oxide together with an excess of copper. At temperatures from 600°C. downward, the precipitated oxides tend to accumulate at the grain boundaries of the alpha phase where a relatively small volume establishes a partial barrier to the diffusion of the reactants- Similarly, large volumes of Precipitated oxides tend to deposit in various patterns that may be expected to

Jan 1, 1944

By F. N. Rhinos, B. J. Nelson

Studies upon the rates of oxidation of copper alloys containing small quantities of the alloying elementsl,2 have shown that steady growth of the scales at predictable rates is limited to a small concentration range and to oxidation at temperatures above 600°C., whereas unpredictable and erratic oxidation behavior is found with alloys containing larger additions and at low temperatures. The latter effect appears to be associated with modifications in the geometric disposition of the oxides. At low concentrations of the baser elements in copper, simple oxidation behavior is typified by the formation of two distinguishable zones of oxidation: (I) a subscale composed of discrete particles of the oxide of the alloying element embedded in substantially pure copper and (2) an external scale composed of cuprous oxide (with a very thin layer of cupric oxide on the outside) containing particles of the alloying element distributed throughout, but most profusely near the metal surface (see Fig. 2, top). Where this type of structure obtains, the process of oxidation is believed to be implemented, and its rate controlled, by the diffusion of the reacting elements through a&apos; continuous matrix phase; i.e., through the alpha (metallic) phase of the subscale and alloy and through the cuprous oxide of the external scale. Copper is presumed to diffuse outward through the cuprous oxide layer to the external surface, where it reacts to form more cuprous oxide.3 Oxygen is delivered at the oxide-metal interface in the form of cuprous oxide, which may either react with the alloying element to deposit its oxide at the inner limit of the external scale or dissolve in the pure copper that remains at the surface of the metal after it has become depleted in its oxidiza-ble alloying elements. Both oxygen and the alloying element are pictured as diffusing through the metal, the oxygen inward and the alloying element outward. Where the two diffusion streams meet in sufficient concentration the oxide of the subscale is precipitated. If the oxygen pressure in the surrounding atmosphere is just below the pressure necessary to maintain cuprous oxide undecomposed, no cuprous oxide can be formed; some of the oxide of the alloying element may form upon the external surface, if its decomposition pressure is below that of cuprous oxide, and a normal sub-scale appears. This condition is achieved experimentally by enclosing the alloy with cuprous oxide together with an excess of copper. At temperatures from 600°C. downward, the precipitated oxides tend to accumulate at the grain boundaries of the alpha phase where a relatively small volume establishes a partial barrier to the diffusion of the reactants- Similarly, large volumes of Precipitated oxides tend to deposit in various patterns that may be expected to

Jan 1, 1944