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By Clarence E. Sims

An effort has been made to give both a comprehensive and simplified picture of the origin, modes of formation, and characteristics of nonmetallic inclusions in steel. Exogenous inclusions, those formed by mechanical entrainment or heterogeneous reaction, have their principal source in ladle refractories. Mechanical emulsion is not considered a likely mechanism. Endogenous inclusions, resulting from homogeneous reactions, are formed mainly during cooling and freezing. They are principally oxides and sulfides but include some nitrides and carbides. Deoxidation affects both the quantity and character of such oxide inclusions and significantly affects the size and shape of sulfides. The importance of inclusions is largely in their effect on mechanical properties. It is fitting and proper that we should honor the memory of those technical giants who have left such a rich heritage to our profession. Today, according to annual custom, we pay tribute to such a man. To have been chosen to play a part in this observance prompts in me an inordinate pride while I am humble before the responsibilities of my task. The ranks are growing thin of those who had the good fortune to come under the personal influence of Professor Howe, but the number who continue to benefit from his legacy of technical wisdom con-stantly increases. I am among the latter. One has only to read his works to appreciate his unusual ability to take data and observations from many sources and give them a clear and comprehensive

Jan 1, 1960

By Paul E. Rosten

Introduction This papers describes some of the latest improvements that have been incorporated or planned by the Cleveland-Cliffs Iron Co. to reduce operating costs and improve pellet quality. The Cleveland-Cliffs Iron Co. operates and manages mining, beneficiation, and pelletizing operations in Michigan, Canada, and western Australia. This paper deals with the grate-kiln pelletizing operations at Republic, Humboldt, Tilden, Empire, and Pioneer in Michigan, and the Adams and Sherman in Ontario, Canada. Table I characterizes each operation in regard to location, ore type, pellet capacity and date that pellets were first produced. All of the operations with the exception of Pioneer and Tilden, utilize downdraft-two-pass grate cycles of drying followed by preheating. Pioneer utilizes an all-downdraft, three-pass grate cycle which consists of three drying zones followed by the preheat zone. The Pioneer and Tilden cycles have been described previously (Lindroos and Koski, 1966; Villar and Dawe, 1975; Koski, 1977). Tilden utilizes a three-pass grate cycle with a stage of updraft drying, followed by two downdraft drying stages. Recuperation systems which supply hot gases to a drying zone from second stage cooling were designed and fur¬nished for Tilden I. Tilden II will be identical. Empire IV will also be furnished with a recuperation system. The Adams grate¬kiln system was retrofitted with a recuperation system. This paper will summarize some of the efforts that are in effect or planned for grate-kiln pelletizing systems to: (1) reduce operating and maintenance costs, (2) reduce energy requirements, (3) improve product quality, and (4) meet environmental standards.

Jan 1, 1981

THOSE MARKED THUS * ARE MEMBERS, MARKED THUS ?ARE ASSOCIATES. THESE SIGNS DOUBLED INDICATE LIFE MEMBERS AND ASSOCIATES RESPECTIVELY. THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP. *AARONS, J. BOYD, Vivian Gold Mining Co., Ltd., Harris, West. Australia. '05 *ABADIE, EMILE R., Cons. and Min. Engr., 214 Union Savings Bank Bldg., Oakland, Cal. '76 ?ABBÉ, MAX F., Prest., Abbé Engineering Co, 220 Broadway, New York, N.Y. '07 ? ABBÉ, PAULO., Secy.,Abbé Engineering Co., 220 Broadway, New York, N.Y. '07 *ABBOTT, AI ARTHUR Morococlia, Peru, So. America. '95 *ABBOTT, CLARENCE Chief EDgr., Iron Mines, Dic Tennessee Caol, Iron & R. R. Co., Bessemer, Ala. '04 *ABBOTT, JAMES W., Min. Engr: Ploche, Lincoln Co., Nev. '94 *ABE, MASAYOSHI, Prof. of Mining, Imperial University Kyoto, Japan. '05

Jan 1, 1910

By J. E. McDonald, J. G. Eberhart

A model is discussed from which the work of adhcslon .tor liquid transition metals on aluminum oxide surfaces can he calculated, A close-packed (00011 oxygen surface on A12O3 is assumed with two different types of surface sites: one type involving metal-oxygen bonds and the other man der Waals into actions. The work of adhesion is thus expressed as the sum of these two bonsding free energies. Calculated works of adhesion for nickel, titanium, chromium, and zirconium on sapphire agree well with the experimentally determined quantities. The model is extentled to the calculation of the work of adhesion and shear stress required to remove a thin metal film from a sapphire substrate and is in good agreement with experimental values. The obsewed dependence of the work of adhesion on the free energy of oxide formation of the metal is shown to also provide an interpretation of the tittle dependence of thin-film adhesion. THIS paper presents a model for the type of bonding which occurs across a metal-A12O3 interface. The model is used to explain the results of two types of experiments in which such an interface exists: 1) the adhesion of thin metal films on Al2O3 substrates and 2) the wetting of A12O3 by liquid metal drops. The adhesion of thin films to various substrates has been the subject of a variety of investigations.'-' Benjamin and weaver3 and Bowie,6 using the scratch test developed by Heavens,10 studied the adhesion of metallic films to glass substrates. Their observations for noble-metal film adhesion agree well with an adhesion model involving a van der Waals type of bonding between the film and the substrate. For films of metals whose free energy of oxide formation. ?F°f, has a negative value. Benjamin and weaver3 and Bowie6 found a time-dependent adhesion with an initial value that can be interpreted in terms of van der Waals interactions but a larger terminal value which was related to ?F°f, Karnow-sky and Estill7 deposited films on sapphire at elevated temperatures and noticed no time dependence of film adhesion but a similar correlation with ?F°f. Because of the kinetic problems associated with thin-film adhesion it is desirable to examine adhesion in an equilibrium system. The wetting behavior of liquid-metal drops on Al2O3 provides such a system. Systems of this metal-ceramic type have been studied extensively.11 Humenik and Kingeryl2 have measured the wetting of A12O3 (and other substrates) by several metals and have pointed out that the wetting ability of these metals increases with increasing values of -?F°f. It is thus seen that thin-film adhesion and metal wetting on A12O3 are both related to the tendency of the metal to react with the surface oxide ions of the Al2O3 substrate and, because of this, both phenomena should be explainable by an appropriate model for the metal-Al2O3 interfacial bonding. In the sections that follow, wetting and adhesion data on A2O3 are reviewed and a model is presented by which these phenomena can be interpreted. ANALYSIS OF WETTING EXPERIMENTS In an equilibrium system involving a liquid-metal drop on a solid Al2O3 substrate, the work of adhesion, WAD, is defined by the Dupre, equation as WAD = ?s + ?L -?sL [1] where ?s and ?L are the surface free energies of the solid substrate and the liquid drop, respectively, and ?sL is the interfacial free energy. The work of adhesion is the work required to separate a unit area of the solid-liquid interface into two surfaces. The work of adhesion is usually determined from a sessile-drop experiment in which yL and the contact angle, ?, are measured. The Young-Dupr6 equation is then used to calculate WAD Wad = ?L (1+ cos ?) [2] The literature of this subject has been examined and Table I shows work of adhesion data for various liquid metals as measured on A12O3 substrates. The standard free energy of oxide formation of the metal at the temperature of the wetting experiment, ?F°f . is also tabulated in kcal per g-atom of oxygen. The data is grouped according to the gaseous atmos-

Jan 1, 1965

By David White

Jan 1, 1925

By E. B. Spice

Although much may be learned about the economics of cold weather operations by studying successful mining ventures in southern and central Canada, it is the purpose of this article to extend the study by considering only permafrost areas. Geographically this means most of the country north of the 60th parallel. In this area, at the present time, only five Canadian companies are carrying on routine and successful mining operations on a year-round basis. However, there have been some score of unsuccessful ventures, and a number of properties in the development stage show promise of being producers. Problems of cold weather are worthy of study. It may be pointed out that successful mines in this area face problems of isolation and costly transportation as well as cold weather. To reach valid conclusions, consider the development of a mythical mineral deposit located on the 65th parallel in the heart of the barren lands; problems of isolation and transportation will be ignored.

Jul 1, 1956

By Victor J. Miller

The Northeast Tripp Slide is one of the larger slope failures that can be attributed to open pit mining. It is a 11.7 million cubic meter (15.3 x l0 6 yd3) wedge failure created by two thick gouge-filled fault zones whose intersection plunges into the Tripp pit at 13°. One unique aspect of this failure is that the slide is now stable despite having moved an estimated 8.5m (28 ft.) towards the pit and having reached a maximum overall velocity of 2lmmlday (0.07 ft/day). The slide started to fail in 1968, accelerated until mining in the slide's toe area was halted in April 1970, then began to decelerate. With the cessation of mining in the toe area, rubblized rock sloughed into the pit bottom which added weight to the failures toe constraints and began the stabilization process. Measurements from a network of survey stations revealed a correlation between the slide's velocity and heavy precipitation. Runoff water accumulating in the tension cracks is believed responsible for this correlation. Moreover, the survey net measurements showed that during the failure's last stage the vertical component of the slide's movement greatly increased. It is proposed that this settling was caused by plastic-like flowage of the clay gouge underlying the failure The fault zone's effective shear strength was estimated by a back- analysis on the wedge's geometry and by performing direct shear tests. The tests, performed on cores taken from samples that were collected on the failure, yielded a residual shear strength of: cohesion 0.61 kg/cm2 (8.7 lb/in2), and a friction angle of 9.6°. This residual shear strength was near1y equal to the back-calculated strength indicating that the controlling fault's effective strength was essentially the same as the residual shear strength of the gouge filling

Jan 1, 1983

By Arthur Forsyth

A SEARCH through the available literature shows that the cobalt-nickel-silicon system has not been systematically studied. This seems rather odd because all three elements are fairly abundant and have better than average corrosion resistance; however, they have high melting points, which makes experimental work difficult. Cobalt and nickel form a continuous series of solid solutions and each metal dissolves about 7.5 per cent silicon. Many ternary alloys have been studied and the results have been published in a great many different ways, but to present such data in a short but clear and understandable manner is still a problem. The following pages describe the results of the study of 76 alloys from which the partial ternary diagram (Fig. 1) of the cobalt-nickel-silicon system has been drawn. The alloys were chosen according to the plan in Fig. la by taking definite ratios of cobalt and nickel, such as 70 Ni, 30 Co or 40 Ni, 60 Co, and adding silicon in various percentages. Each section was studied in detail by means of thermal analysis and microscopic examination, but only two of these detailed sections were thought necessary in the point perspective drawing to give a comprehensive picture of the liquidus, solidus and solid transformations that take place over the temperature ranges studied. Complete thermal analyses and microscopic data are given in Table 1.

Jan 1, 1940

By W. W. Norton

The gradually increasing proportion of sulphide ores which lead smelters of to-day are called upon to handle has caused the roasting problem to become one of ever greater importance. Mines have increased in depth, methods of concentration have improved, competition in the purchase of ores has become more keen and it has been clear that new and modern methods of eliminating sulphur must receive a large share of attention. We may look back a score of years or so and recall the old hand roasters, some of which turned out a finely divided roasted product, and others fashioned with a "fuse-box" wherein the roasted ore was slagged. Then came mechanical furnaces of several types, the Bruckner cylinder, the Brown-O'Harra, the Ropp, and others, all designed to cut out the cumbersome hand labor of the old reverberatories. Roasting costs were thereupon reduced and tonnages stimulated to a gratifying extent. However, it seems to have been early recognized that this very feature of a greater amount of roasted sulphide ore as compared with oxide ore brought with it a train of difficulties at the blast furnaces. The mechanically roasted ore was fine physically, the blast furnaces were choked and the troubles of the smelterman were not at an end. Then the Huntington-Heberlein pot system of roasting appeared upon the scene, and later on the Dwight-Lloyd machines were invented, and inasmuch as both of these processes were designed not only to roast the ore but to agglomerate it as well, it was apparent that distinct steps in advance had been achieved. At the Murray plant, modern up-to-date roasting practice is fully exemplified and there are now in successful operation roasting furnaces or devices of several sorts: namely, Godfrey revolving-hearth furnaces, Wedge multiple-hearth mechanical roasters, Dwight-Lloyd sintering machines, and Huntington-Heberlein pots. Godfrey and Wedge furnaces will properly handle material high in sulphur, say ores with 25, 30, and 35 per cent. of that element; D. & L. machines and H. & H. pots will positively not treat efficiently ores or mixtures containing anywhere near the sulphur content mentioned, but are confined to charges containing in the neighborhood of 15 or 18 per cent. In passing, it may also be explained that, so far as the knowledge of the writer goes, Godfrey and Wedge furnaces do not economically eliminate sulphur to an extent

Jan 1, 1915

By OTTO HERRES

TITANIUM is estimated to be the ninth most plentiful element, ranking after iron, aluminum, and magnesium, and ahead of copper, lead, and zinc. Vast quantities of titanium are widespread throughout the world in ore deposits and beach sands. Before the war, processing plants were operated in England, France, Italy, Czechoslovakia, Norway, Russia, Australia, United States, and Japan. In spite of its widespread occurrence, however, the U. S. Department of Justice has held the titanium industry to be a world monopoly and action was taken in the Federal court during the summer of 1945 to enjoin international patent and marketing agreements and to restore free competition. Possibly the rather surprising lack of public familiarity with this industry of international importance arises from its astonishingly rapid development and growth in the strong hands of some of the greatest chemical companies in the world, including the important foreign companies, Imperial Chemical Industries (British), Montecatini (Italian), I. G. Farben (German), and Titan Kogko Kabushiki Kaisha (Japanese). The rapid growth of the titanium industry in the United States is indicated by a tenfold increase of ore imports in the 1930 to 1940 decade before the war began to affect shipments from overseas. The fact that the industry formerly derived practically all ore for chemical processing in American plants from foreign sources probably also accounts for lack of general public knowledge of titanium. In 1939, to meet the requirements of increasing demand for the white pigment. titanium dioxide, more than 250,000 tons of titanium concentrates moved to this country, principally from the Travancore coast of India where the ilmenite concentrate from the beach sand runs as high as 60 per cent in titanium dioxide. Global warfare put a stop to shipping and thus gave rise to the development of titanium mining on a substantial scale in the United States during 1941.

Jan 1, 1946

By E. P. Pfleider

Important economic planning by industries, companies, financial firms and governments is predicated on estimates of future growth potential. Prior to the passage of the Taconite Amendment by the people of the State in November 1964, various admittedly conservative forecasts were made of the future of Minnesota's iron ore industry. Since that date, 3 new taconite plants are under construction, 2 are being expanded, one has just gone "on stream," and a seventh is in the design stage. These plants have a total capacity of about 35 million tons of pellets annually. The pessimism of 1964 today is being replaced by unbounded optimism. In the light of such recent developments, it becomes essential to update forecasts related to production, employment and capital investments. New projections show 50 to 58 million tons of pellet production from Minnesota by 1975. This tonnage, together with some 6 to 8 million of natural ores, should provide an annual full-time employment of 15,000 by the mining companies, plus 700 in related railroad and power producing activities and 1000 in plant construction. Total capital investment in new plants should reach $1.5 billion by 1975 and $2 billion by 1990. These current estimates indicate that the conservative goals as set in 1964 for the year 1990 should actually be achieved by 1975 or 1980. BACKGROUND Various forecasts1,2,3 have been made of the future consumption and production of iron ores within the United States. The most recent of these is by Harrison,1 delivered at the American Mining Congress meeting in Las Vegas in October. His estimates reflect the latest iron ore developments on a world wide front as well as the accelerating trend toward pellets. Minnesota's Natural Resources council prepared a detailed report in 1964 outlining the various factors that affect the future of Minnesota's iron ore industry. It presented estimates predicated on the

Jan 1, 1967

By Paul R. La Pointe

GEOTECHNICAL OBJECTIVES OF UCG PROGRAM Underground coal gasification (UCG) is one of several in situ extraction technologies for utilizing deep, otherwise unmineable coal. This technology involves the injection of air or oxygen into the target coal seam, ignition of the coal and recovery of product gases. Geotechnical characteristics of the coal and enclosing rock strata strongly influence the success of this Process. The flame front follows the coal cleats (Hill, 1979), and cleating and bedding control the manner in which coal collapses into the cavity, thereby affecting recovery efficiency (Ramirez and others, 1982). Moreover, coal seams typically behave as fracture dominated aquifers in which cleat orientations govern subsequent contaminant dispersal. For these reasons, the Anaconda Minerals Co. undertook a detailed study of fracturing within the Wyodak-Anderson Coal in the eastern Powder River Basin (PRB) near its Rocky Hill UCG test site (Fig. 1). STRESS HISTORY AND FRACTURING IN THE POWDER RIVER BASIN Vertical jointing, or cleating, in coals may arise from shrinkage shortly after deposition under low confining pressures, or later in time, soon after burial but after the coalification process is well advanced (Ting, 1977). There is much evidence to support the formation of cleating after coalification (e.g. Hawkes and Mellor, 1970; McCulloch and others, 1974), which suggests that the stress state existing at that time strongly influences cleat formation. McCulloch and others (1974) argue that the typically better developed face cleat forms parallel to the plane containing [ol] and [o2]. Where the relation between cleats and stess has been studied (McCulloch and others, 1974; Stone and Snoeberger, 1977; Ward, 1977; Kulander and Dean, 1978), the highly systematic face cleat strongly parallels the [o1] direction. Stone and Snoeberger (1977) report face and butt cleat measurements of N70E and N29W for the Felix Coals 220 m stratigraphically above the Wyodak at the Hoe Creek UCG site (Fig. 1). Structural trends also indicate the past state of stress in the PRB. Glaze and Keller (1963) suggest that the NE-SW regional compression during the late Permian formed major N-S fold lines and basement magnetic anomalies. Mapel (1959) describes folds having N60W and N30W rends in the northern PRB, as well as a large normal fault trending northeast. Glass (1976) also describes normal faults trending northeast. Similarly, Olive (1957) mapped normal faults

Jan 1, 1984

By O. P. Arora, M. Metzger

Single-phase aluminum containing 1 to 600ppm copper was studied in 7 to 26 pct HCl. The corrosion rate in the autocatalytic stage was resolved into a constant intrinsic component and an acdelerating autocatalytic component, and attention was focused on the part of this stage where the corrosion rate could be described by a simple empirical relation. Autocatalytic corrosion in this period was localized and its rate increased rapidly with copper content and with the strength and chlaride content of the acid. The effects of adding cupric ion to 16 pct HCI were functionally and quantitatively inconsistent with the autocatalytic rates observed. A theory of these rates was given based on the deposition in nzetallic contact with the aluminum of part of the copper introduced by corrosion. It has long been known in a general way that aluminum containing sufficient copper suffers in hydrochloric acid an autocatalytic acceleration of corrosion resulting from the introduction into the acid of copper ions and their reduction on the specimen as elemental copper, which provides cathodes of low hydrogen overvoltage.'-3 In a previous paper, this phenomenon was identified in single-phase high-purity material at copper levels as low as 20 ppm and an empirical equation describing autocatalytic corrosion rates in 16 and 20 pct HC1 was presented. In the present work the range of acid strength and chemistry studied was extended, a more accurate empirical equation for the autocatalytic rate was determined, and a theory of this rate was formulated. A major source of interest in this system is the intergranular corrosion, which is also strongly influenced by copper content,= and an objective of the present work on general corrosion was to provide a basis for studying the role of copper content in intergranular corrosion, which is experimentally much less accessible.

Jan 1, 1963

Aamot, Olav Crone, Chem. Engr., Norsk Elektrokemisk, Kongensgt. 18, Oslo, Norway. '29 Abbott, Clarence E., V.P., Charge of Raw Materials, Tennessee Coal, Iron & R. R. Co., 1242 Brown-Marx Bldg., Birmingham, Ala. '04 Abel, Raymond L., Prof., Dept. of Pet. Refin., Univ. of Pittsburgh ..Pittsburgh, Pa. '28 Abel, Walter D., Cons. Engr 364 S. Cloverdale Ave., Los Angeles, Calif. '32 Abele, Louis T R.F.D. 1, Adamsville, Ohio. '31 Abell, Leo M., Ore Dressing Investigator, School of Mines Adelaide, S. Australia. '31 Abenius, Hakan V., Mine Supt., Bolidens Gruvaktiebolag Boliden, Sweden. '37 Aborn, Robert H., Asst. Met., Research Lab., U. S. Steel Corp., Lincoln Highway, Kearny, N. J. '19 Abraham, W. E. V., East India United Service Club, 16 St. James' Sq., London, S.W. 1,, England. '28

Jan 1, 1937

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 H. W. Gillett

MAINTENANCE of membership by the technical so¬cieties and the activity of these societies in spite of the adverse business situation have been noteworthy. This forcibly brings home the fact that industry recognizes that sound technical guidance is well worth its cost. The numerous difficulties and losses due to defects of various kinds arising from gas-metal reactions are now generally recognized and interest in these problems is widespread. The forthcoming A. I. M. E. round-table discussion of gas-metal problems will do much to clarify the situation and will permit us to assay our present knowledge and to suggest the proper direction for profitable future research. "The Age Hardening of Metal" was the title of the annual I. M. D. lecture delivered by Dr. Paul D. Merica. A critical review of the known facts relating to age-hardening phenomena was first given, followed by the presentation of a theory correlating the detailed observations which have been made regarding the mechanism of the hardening.

Jan 1, 1933

By Dean Goodermote, Carla S. Stone

I Introduction Coal fuels China. Roughly 70 percent of all commercial energy demand is supplied by domestic coal production and with the recent Chinese opening to the West, the Chinese Coal Industry may figure prominently in the export market as well. Because of the importance of China's coal industry to the future of China and the Pacific Rim energy balance, this paper reviews the industry and offers some cautious projections for its outlook. II Energy's Position in the Current Political and Economic Climate Traditionally, Chinese society has been dominated by the policies of its most important government leaders. Deng Xiaoping, Vice Chairman of the Communist Party is the current leader of China. Deng and his proteges are pragmatists. Although China's government structure is based on Marxist/Leninist tradition, Deng and his followers are promoting experiments with market economics and expanded relationships with Western Countries, which have encouraged foreign investment in China. Energy companies represent just one type of industry that is interested in helping the Chinese to develop their abundant natural resources. Although China's leadership is committed to a program of economic modernization, that program currently is experiencing what the Chinese government terms "readjustment". Readjustment cuts back in imports due to deficient foreign exchange and deemphasizes heavy industry, while it encourages agricultural and consumer goods output and, most imporant, energy production. Increased Chinese coal and oil production is essential both to fuel industry and, equally important, to provide foreign exchange. If sufficient energy production is not forthcoming, then economic growth will be severely retarded. China's 1979 per capita GNP of $260 is only slightly better than the weighted average achieved by low income countries of $230. (1) Delays in growth could lead to social unrest, threatening the position of the current leadership. Since there is no institutionalized mechanism for leadership succession and policy continuation, it is reasonable to assume that leadership changes could result in energy policy changes. III Energy Consumption Energy production is important to China's future economic health as highlighted by the World Bank. If China's economy grows rapidly, 5 percent to 6 percent during this decade, the Bank noted, a significant energy shortfall could occur as early as 1985. This state of affairs contrasts sharply with China's current position as a net hydrocarbon exporter. (2) To assure a healthy economic future, China's leadership is attempting to reduce its rate of increase in energy demand through conservation as well as to boost energy output. A massive conservation promotion program has been underway since 1979 and there is much room for improvement. China's industrial sector is only about half as energy efficient as is U.S. industry. (3) During the last two decades, each percent of increase in GNP has been accompanied by a 1.8 percent of increase in energy consumption. (4) This compares rather poorly with the United States where a less than one-to-one relationship exists. IV Energy Supply The short term prospects for oil production are uncertain. Production increases were rapid in the 1960's and early 1970's, averaging 20 percent annually, but most of this increase came from one field, Daquing. Now that Daquing's production has peaked and the offshore potential has yet to be developed, petroleum production has maintained a plateau of 2.1 million b/d, at least temporarily, of which approximately 15 percent is exported. (5) Output

Jan 1, 1982

By M. F. Hawkes, R. F. Mehl

The rate of isothermal transformation of austenite to pearlite depends upon the rate of nucleation, N, and the rate of growth, G, of pearlite in austenite. Values of N are given in terms of the number of nuclei forming in unit time per unit grain boundary area of unreacted austenite; values of C are given in terms of the linear rate of radial growth. Variations in the isothermal rate with temperature result from variation of N and G with temperature. Depth of hardening of a steel depends fundamentally upon values of N and G; changes in carbon and alloy content effect changes in N and G and thus affect depth of hardening. Quantitative studies are available on N and G for the formation of pearlite in plain carbon eutectoid steels.3 Systematic studies in this field are necessary if the phenomena are to be well enough known to furnish a proper basis for full rationalization and for theory. Accordingly, the studies are continuing, both with respect to the effect of alloying elements upon the values of N and G in the formation of pearlite and to the values of N and G for the formation of ferrite in hypoeutectoid steels. The present paper is the first relating to the effect of alloying elements upon the values of N and G for pearlite. It offers special interest since cobalt is known to have an anomalous effect upon the rate of formation of pearlite, accelerating it, whereas all other elements retard it.4 It will be shown that cobalt increases both N and G for pearlite and that this effect is inherent in the Fe-Co-C system and not dependent upon factors relating to austenite heterogeneity nor upon any recognizable adventitious factor. Inasmuch as the rate of diffusion of carbon in austenite and the interlamellar spacing of pearlite are variables related to G and possibly to N (in a manner not yet certain), measurements of the effect of cobalt upon them are also reported here. In the course of the work, measurements were made on the effect of cobalt upon the marten-site temperature and these are given. COBALT AS AN ALLOYING ELEMENT IN STEEL Properties of Cobalt Cobalt resembles iron more closely than does any other chemical element. Its atomic number is 27, hence it is the element immediately following iron in the periodic system. The two differ in atomic structure only in the fact that cobalt contains seven electrons instead of six in the third, or transition, level of .the third shell. The next shell, which is the

Jan 1, 1948

By M. F. Hawkes, R. F. Mehl

The rate of isothermal transformation of austenite to pearlite depends upon the rate of nucleation, N, and the rate of growth, G, of pearlite in austenite. Values of N are given in terms of the number of nuclei forming in unit time per unit grain boundary area of unreacted austenite; values of C are given in terms of the linear rate of radial growth. Variations in the isothermal rate with temperature result from variation of N and G with temperature. Depth of hardening of a steel depends fundamentally upon values of N and G; changes in carbon and alloy content effect changes in N and G and thus affect depth of hardening. Quantitative studies are available on N and G for the formation of pearlite in plain carbon eutectoid steels.3 Systematic studies in this field are necessary if the phenomena are to be well enough known to furnish a proper basis for full rationalization and for theory. Accordingly, the studies are continuing, both with respect to the effect of alloying elements upon the values of N and G in the formation of pearlite and to the values of N and G for the formation of ferrite in hypoeutectoid steels. The present paper is the first relating to the effect of alloying elements upon the values of N and G for pearlite. It offers special interest since cobalt is known to have an anomalous effect upon the rate of formation of pearlite, accelerating it, whereas all other elements retard it.4 It will be shown that cobalt increases both N and G for pearlite and that this effect is inherent in the Fe-Co-C system and not dependent upon factors relating to austenite heterogeneity nor upon any recognizable adventitious factor. Inasmuch as the rate of diffusion of carbon in austenite and the interlamellar spacing of pearlite are variables related to G and possibly to N (in a manner not yet certain), measurements of the effect of cobalt upon them are also reported here. In the course of the work, measurements were made on the effect of cobalt upon the marten-site temperature and these are given. COBALT AS AN ALLOYING ELEMENT IN STEEL Properties of Cobalt Cobalt resembles iron more closely than does any other chemical element. Its atomic number is 27, hence it is the element immediately following iron in the periodic system. The two differ in atomic structure only in the fact that cobalt contains seven electrons instead of six in the third, or transition, level of .the third shell. The next shell, which is the

Jan 1, 1948

By AIME AIME

A discussion of the Papers by Prof. H. Hubert, Liege, Belgium ; Mr. Tom Westgarth, Middlesbrough, England ; and Mr. K. Reinhardt, Dortmund, Germany, presented at the London Meeting, July, 1906, and printed in Bi-Monthly Bulletin, No. 12, November, 1906; pp. 910 to 930, 971 to 987, 1037 to 1163. MR. ADOLPH GREINER, Seraing, Belgium :-I have nothing special to add to Professor Hubert's paper except to say that there are some little things that it would be well to have cor-rected when the paper comes to be published. In dealing with the thermal efficiency of the engine, you will find that the 29.84 per cent was a very high one. Professor Hubert has forgotten those engines built under the Cockerill type, but he has referred to them in Appendix II. At our works at Cockerill we have built 63 engines, giving 63,000 h.p., and the other companies who have received licenses have built 113 engines, making 103,000 h.p., and aggregating 176 engines and 166,000 h.p. Eight years ago I had the pleasure of giving to the Institute the results obtained up to that time. Since then a good many engines have been constructed. In 1898 I thought a blast-furnace producing 100 tons of pig iron would allow 3,000 h.p. Professor Witz and Professor Hubert show that with the same production of pig the new engines take 3,800 h.p. out of the gas. At present at Cockerill we make 700 to 800 tons of pig iron per day, and we hope to have 26,000 h.p; in a few years. At present we have only half of that in gas-engines, but we hope to have in five or six years all the gas out of these furnaces to the number of 25,000 or 26,000 h.p. MR. Tom WESTGARTH, Middlesbrough, England:-My contribution is not a paper in the ordinary sense of the word, because I am sure you will agree with me that what I have written is only supplementary to the other two papers. The notes are schedules of the larger-size gas-engines built by the engine-makers, of 500 h.p. and upwards. If you look at the schedules you will find that in England gas-engines have be-

Jan 1, 1907