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By Archiblad MacMartin

The Kunigin-Marien-Hiitte is the only works in Germany where the Bessemer process is carried on by the direct method. The Besserner plant there, is arranged after the true English type, and the only resemblance to the Swedish mode of 'procedure is the dispensing with the use of spiegeleisen at the end of the "blow." In a new department of the establishment, started within three years, each of the converters is turned by means of a very neat and compact reversible engine, the steel shaft of which is an endless screw, which turns against the oblique cogs of a large wheel attached to the shaft of the vessel. An advantage which this arrangement possesses over the ordinary English hydraulic arrangement, is the fact that the endless screw suffices to turn the vessel, in either direction, any number of complete revolutions; while even the latest American improvements, so clearly explained to us by Mr. Holley at the opening session of this meeting, do not secure even one complete revolution without changing the angle of inclination of the hydraulic piston. In the endless screw arrangement, there being no limit to the working of the motor in either direction (no return-stroke necessary), the vessel can always, unless outside reasons demand the contrary, be turned around to any desired position by the shortest cut, whether backwards or forwards. Also, the diameter of the cogwheel attached to the vessel can be made sufficiently great to avoid all unevenness of motion. In the old department the motive-power still continues to be hydraulic. If reports be true, the new department produces spiegelized steel, for the manufacture of all-steel rails. But the old department is still, as from the beginning, devoted to the production by the direct method of steel for steel-headed rails. The most remarkable fact connected with this direct steel is the ease with which it welds to the iron 'of the rail-packets, although no borax or other fluxing agent is used to facilitate the welding. It is very rarely that an exception occurs, and an ingot or a charge is discarded by the rail-mill. The mixture of pig-iron used for the production of this steel is melted in cupolas of very interesting construction (not to be de-

By W. J. Taylor

Some eight years ago I became interested to a considerable extent in one of the well-known deposits of sulphury iron ore in New Jersey, and, as a consequence, soon became interested in the subject of the elimination of the sulphur. On investigation I found that no department of pig-iron manufacture had received less attention than that of roasting or calcining ores for the elimination of sulphur, carbonic acid, water, etc. My first devices to eliminate sulphur mere naturally in the limekiln line, with solid fuel mixed with the ore, in the same way = common lime is burnt with small coal. While this process will succeed tolerably well for carbonates or calcareous ores, even though they contain sulphur as sulphates, I soon found it would not answer for our magnetites, which are very hard and dense, carrying from 2 to 5 per cent. of sulphur as pyrites, and become very sticky as soon as any attempt is made to roast them at a high heat. Some laboratory experiments developed the fact that the nearer the gaseous current surrounding the hot ore approached in composition pure atmospheric air the more rapidly the sulphur was oxidized, while in an atmosphere composed largely of carbonic oxide, carbonic acid, and nitrogen, it seemed almost impossible to reduce the sulphur more than one-half, which was a confirmation of the well-known Pact that just one-half of the sulphur in pyrites volatilizes very easily, and that the trouble is mainly to remove the remainder. It was thus apparent that the atmosphere surrounding the ore was of as much importance as the temperature..• This led to the trial of a kiln to heat the ore by conduction through the brick. It was divided into ore-chambers, which were surrounded with flues, through which the products of combustion of gaseoua fuel passed without coming in contact with the ore. We did not, however, succeed by this arrangement in getting more than a cherry-red heat, which, of course, was too low to accomplish anything. I had at this point become convinced— 1st. That gaseous fuel only would accomplish the work successfully. 2d. That since a high temperature was required to insure a rapid oxidation of the sulphur, and also to make the ore open and porous,

Jan 1, 1881

By James E. Lawver, Jose M. Pastrana

Some of toe magnetic properties of minnesotaite (general formula: Fe3(OH)2Si4O10) were examined. Toe paramagnetic susceptibility values at various temperatures were determined from toe slope of toe magnetizing curve. These values were then compared with toe theoretical values estimated using toe Bohr magneton numbers for toe paramagnetic ions contained in toe missesotaite.

Jan 1, 1975

By Frederick N. Rhines

Pure copper that has been allowed to oxidize at an elevated temperature in the air is found to be covered with two distinguishable layers of oxide scale. The outer of these, which is very thin, is composed of cuprie oxide, while the inner layer, comprising the bulk of the scale, is made up chiefly of cuprous oxide (Fig, la). If a small quantity of an alloying element, such as silicon, is present in the copper, silica particles are found disseminated through the cuprous oxide, deposited most abundantly near the metal surface, and, in addition, silica particles occur to a limited depth within the copper itself (Fig. 1b). It is this inner layer, composetl of oxide particles precipitated in a matrix of metallic copper, that is known as the "subscale" or the zone of internal oxidation. Under a low oxygen pressure it is possible to produce the subscale without the formation of external layers of copper oxides, thus leaving the metal surface bright and apparently clean while oxidation has occurred, in fact, to a considerable depth within the metal (Fig. 2). Although little is yet known in a detailed way of the mechanism of internal oxidation, the general nature of the process is evident. By virtue of the considerable solubility of oxygen in copper,' it is possible to bring the alloying element in contact with oxygen within the metallic solid solution. If the oxide of the alloying element is more stable than cuprous oxide, the foreign oxide may form and, since most oxides are relatively insoluble in copper, it will not long remain in solution, but mill separate as a precipitate. As the metallic solute is exhausted in the zone of precipitation, oxygen that is constantly being supplied at the surface diffuses farther into the alloy and thus produces an ever-thickening shell of subscale. The distribution of the reacting elements in the subscale and adjoining zones must be somewhat as indicated in Fig. 3. The conditions requisite to internal oxidation to be anticipated are thus: (I) a solubility of oxygen in the alloy, (2) the ability of oxygen to diffuse at an appreciable rate into the alloy, (3) the possibility of the

Jan 1, 1940

By Frederick N. Rhines

Pure copper that has been allowed to oxidize at an elevated temperature in the air is found to be covered with two distinguishable layers of oxide scale. The outer of these, which is very thin, is composed of cuprie oxide, while the inner layer, comprising the bulk of the scale, is made up chiefly of cuprous oxide (Fig, la). If a small quantity of an alloying element, such as silicon, is present in the copper, silica particles are found disseminated through the cuprous oxide, deposited most abundantly near the metal surface, and, in addition, silica particles occur to a limited depth within the copper itself (Fig. 1b). It is this inner layer, composetl of oxide particles precipitated in a matrix of metallic copper, that is known as the "subscale" or the zone of internal oxidation. Under a low oxygen pressure it is possible to produce the subscale without the formation of external layers of copper oxides, thus leaving the metal surface bright and apparently clean while oxidation has occurred, in fact, to a considerable depth within the metal (Fig. 2). Although little is yet known in a detailed way of the mechanism of internal oxidation, the general nature of the process is evident. By virtue of the considerable solubility of oxygen in copper,' it is possible to bring the alloying element in contact with oxygen within the metallic solid solution. If the oxide of the alloying element is more stable than cuprous oxide, the foreign oxide may form and, since most oxides are relatively insoluble in copper, it will not long remain in solution, but mill separate as a precipitate. As the metallic solute is exhausted in the zone of precipitation, oxygen that is constantly being supplied at the surface diffuses farther into the alloy and thus produces an ever-thickening shell of subscale. The distribution of the reacting elements in the subscale and adjoining zones must be somewhat as indicated in Fig. 3. The conditions requisite to internal oxidation to be anticipated are thus: (I) a solubility of oxygen in the alloy, (2) the ability of oxygen to diffuse at an appreciable rate into the alloy, (3) the possibility of the

Jan 1, 1940

Discussion of the paper of B. H. Dunshee, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 30, August, 1913, pp. 1511 to 1531. GEORGE E. MOULTHROP, Butte, Mont.:-The recording for the first time by Mr. Dunshee, in a readily usable form, of the various systems of square-set framing applied in the Butte district is a valuable contribution to mining information. The many different methods of framing employed, due to the individual ideas of superintendents and foremen of segregated companies, have given full opportunity to determine the best framing for the conditions as found in these mines, and the final adoption of a system uniform for all the mines has come about through a study of these various methods and an experience covering a period of many years. The sawed 10 by 10 in. and 12 by 12 in. timbers undoubtedly give the best satisfaction; and the style of framing the sawed timber that under all conditions has given the best practical results is that used in the Anaconda group and other mines, described and recommended by Mr. Dunshee. In this framing the posts have a horn 2 in. high and 6 in. square, the cap end having dimensions of 3 by 6 in. Instead of the framed girt shown in the drawings of the Anaconda group, the 6 by 10 in. girt adopted at some other mines, which fits into the cap and post framing with no other preparation than cutting the timber to the necessary length, fills all the necessary requirements for strength and affects a material saving in timber and labor. This, as Mr. Dunshee states, is without doubt the type of framing which would be adopted as a standard for 10 by 10 in. sawed timbers if sawed timber sets were to be used in the future generally. But saw-timber for the mines was becoming scarce and expensive, and round timber for the square sets furnished an alternative which provided, at greatly reduced cost, material which in every way supplied the requirements of the mining conditions. The use of the round timber with a satisfactory framing makes available a conveniently located and large source of supply which up to this time has served no useful industrial purpose. Particularly is this true of small timber, which is still standing in great quantities in the forests where the trees more desirable for commercial purposes have already been cut and marketed.

Jan 11, 1913

By G. A. Moore

A brief review is given of methods designed to produce metallic iron of high purity, and typical results are listed. A recent method, utilized at the National Bureau of Standards, consists of the extraction of ferric chloride by ether, reduction of this ferric chloride to ferrous chloride, further purification of this chloride, and the subsequent electrolytic deposition of metallic iron. iron produced by this procedure apparently is softer than, and otherwise different in properties from, any iron previously prepared and contains appreciably smaller amounts of impurities. THE history of attempts to produce "pure" iron reaches to antiquity and it may be presumed that each ancient armorer who succeeded in making a better steel concluded, correctly, that he had done a better job of removing the "base metals," and incorrectly, that he now at last had a "pure" metal. Early metallurgical papers mentioned use of "pure iron" in making alloys—this "pure" iron in most cases being inferior to some commercial stocks of the present time. Improvement has been continuous, and usually at a sufficient rate to convince each succeeding group of workers that they, at last, were using the really pure metal (until the analysts also improved their techniques to again discover the impurities). These adventures were reviewed in some detail by Cleaves and Thompson.' Although the ores of a metal may be abundant, difficulties in extracting it may make the pure metal very rare. When impurities are restricted to a total of a few parts per million, nearly all pure metals become rarities. Lead, copper, gold, mercury, silver, zinc, aluminum, bismuth, and the six platinum metals are claimed to be available with total impurities ranging from 2 to 50 ppm. The present small and scattered world supply of so-called "pure" iron holds an unimpressive place in another group of 16 metals having approximately 100 ppm of foreign material. Of about 20 less rare metals, only the platinum metals are more costly to prepare. While the production of such rare varieties of iron may appear insignificant in the presence of thousand-ton operations with 95 to 99 pct metal, it must be emphasized that all researches on commercially interesting irons and steels are in fact studies of the modifications of the properties of iron by additional materials. Until the properties of high purity iron are directly measured, all ferrous research must operate without known base values. Traces of impurities may affect the properties of a metal in many ways. Infinitesimal traces of solutes, by disturbing the electronic configuration, greatly change the electrical properties of transistors and semiconductors2-3 and slightly larger traces might alter these quantities in iron. Soluble impurities which disturb the perfection of lattice arrangement not only may alter the magnetic constants and electric properties, but by their close association with dislocation phenomena probably control the very existence of the "yield point"; determine the value of yield stress; and perhaps control the selection of slip and cleavage planes. It has been speculated that impurities might even cause the allotropic transformation in iron, but in any case their rearrangement must contribute to the unreliability of heat capacity and other thermodynamic measurements. Impurities which do not remain in solution may cause even greater effects on the properties. Microscopically visible amounts of phases other than ferrite can be found in all high purity irons which have come to my attention. It can be calculated that from 50 to as little as 2 ppm of an insoluble material might be sufficient to completely film all grain boundaries in irons having grain sizes from ASTM Nos. 10 to 1. Should this occur, such films, even though invisible, may be very important in fracture problems, especially at extremes of temperature:' Studies of grain growth and diffusion normally imply consideration of a single-phase system, hence, in the presence of insoluble impurities they can be expected to give ambiguous data." High purity iron is also in demand for use as chemical and spectro-chemical standards; for work in classifying the lines of the iron spectrum; for biological work in nutrition; and for work in nuclear physics. where the presence of some sensitive

Jan 1, 1954

[ASSETS CAPITAL ASSETS: Equity in United Engineering Society's Land and Buildings $486,792.79 Library 40,000.00 $526,792.79 INVESTMENTS: Jas. Douglas Fund-Schedule #2 $ 99,966.40 Life Membership Fund-Schedule #3 9,415.63 R. W. Hunt Medal Fund-Schedule #4 7,489.09 116,871.12 INVENTORIES: Paper Account 305.10] [ ]

Jan 1, 1925

By Albert E. Ketler

Introduction – The introduction of computerized monitoring and control (M/c) equipment into the U.S. coal mining industry may prove to be of truly revolutionary proportions in the 801s.Many of you are aware that the British have developed and have been using such sophisticated M/C equipment for performing production and safety related tasks in their coal mines for nearly a decade. The benefits of M/C systems in the mining industry are usually separated into those which improve productivity, and hence make money for the company, and those which improve safety, and hence cost money. The economic benefits of M/C are startling for the production related functions such as for monitoring and controlling conveyor belts, de-watering pumps, electrical power distribution, and the like. It doesn't take much analysis to show that hundreds and even thousands of tons of coal don't get mined every time a belt shuts down or when power is out due to circuit breakers tripping for any number of reasons. A flood, caused by a malfunctioning pump which goes undetected for lack of feedback monitoring of pumping parameters, can destroy literally millions of dollars worth of mining equipment. The M/C system would be justified or not based on whether or not the productivity benefits balanced the cost within a timespan commensurate with the return on capital philosophy of the company. The safety related benefits are easily underestimated or ignored completely and the purpose of this paper is to under-score some of these benefits, as well as to review the application of M/C to the coal mining industry. The companies involved are Transmitton Ltd of England and Minetics Corp of Pittsburgh, Pennsylvania. Transmitton is probably the most experienced manufacturer of M/C equipment in the world having some 200 installations to its credit. Minetics is the marketing and manufacturing arm for Transmitton in the U.S.A. and is responsible for all aspects of distribution and service. Plans are underway for manufacturing of the Transmitton hardware for U.S. sales to be transplanted into U.S. subcontractors by 1981. Thus our coal mining industry will benefit from British technology, but without the delays and additional costs usually involved in international shipments.

Jan 1, 1981

By William Colby

INCREASING governmental control of human activities seems inevitable. Within the present generation railroad rates and the public sale of water, gas and electricity have been subjected to rigid regulation. The field of control is slowly but surely being enlarged, and it is the object of this paper to outline in brief space this tendency toward increased governmental regulation, as far as mineral resources are concerned. Our, dual form of government complicates the problem. We must deal not only with the powers of the Federal Government, but also with those of the individual States. In order to approach this question intelligently we must have some conception of the powers and jurisdiction of the States and the United States, respectively, over mineral lands and mineral production. Starting with the Federal Government we find it never owned any public domain within the States that formed a part of the thirteen original colonies and, for historical reasons, the same is true of Tennessee and Texas. The Mid-Western States were erected out of the public domain which was acquired by the United States through cession from the original States or by purchase from foreign nations. Congress early in the last century adopted a policy of leasing public lands containing lead deposits in a portion of this Mid-Western territory, but later abandoned that policy and disposed of such public, lands, mineral and non-mineral, outright so that they long since have practically all passed into private ownership and become subject to the general jurisdiction of the respective State governments. In the great public domain lying west of the Mississippi River, and in portions of some of the Southern States, the Federal Government adopted a new mineral land policy following the discovery of gold in California. (Acts of Congress of 1866, 1870, and 1872.) The mineral lands within these States, instead of being disposed of on the game basis as agricultural lands, as occurred in the Mid-Western States, were segregated from agricultural lands and sold under special laws intended to encourage mining, giving the miner the free right to locate and work these mineral lands without paying any royalty to the Federal Government. A miner could also obtain at slight expense a complete

Jan 1, 1930

K. T. Aust and J. W. Rutter (General Electric Research Laboratory)—We find it difficult to reconcile the activation energies determined by Gifkins with his general conclusion that "migration during both creep and grain growth can thus be treated on the basis of the same model" (that of Lucke and Detert). Gifkins finds the activation energy for grain boundary migration during creep to be 24.5 kcal per rnol and that for grain boundary migration during grain growth to be 7.5 kcal per mol. The calculation carried out by Gifkins of the activation energy for grain boundary migration during grain growth, using the Lucke and Detert model, gives a value of 20 to 24.5 kcal per mol, rather than his experimental value of 7.5 kcal per mol. The theory of Lucke and Detert was developed to account for the rates of migration of grain boundaries in the presence of impurities during grain growth. The theory does not take into account the effect on the boundary migration of another, simultaneous process such as creep deformation and would be expected, therefore, to be applicable only to migration during grain growth. The fact that Gifkins measured a different activation energy for boundary migration during grain growth (7.5 kcal per mol) from that during creep (24.5 kcal per mol), although the specimens were of the same composition, shows clearly that such an effect exists under his experimental conditions; the presence of a simultaneous creep deformation markedly affects the boundary migration process in comparison with what would be observed under the same conditions but without the creep deformation. The failure of McLean's equation (Eq. [4] of Gifkins' paper) to give a satisfactory dislocation density difference for boundary migration during creep is not surprising, since the activation energy which must be used in this equation refers only to the elementary atom transfer process of grain boundary migration. This activation energy value is approximately 6 kcal per mol for zone-refined lead, as determined in both the grain boundary migration experiments of Aust and Rutter31, 32 and the grain growth experiments of Bolling and Winegard.33 Using this activation energy value, McLean's equation gives reasonable agreement with observed migration rates for grain boundaries moving free of the influence of impurities.31, 32 The value of 24.5 kcal per mol is probably associated with the presence of impurity atoms, as Gifkins suggests. It should be noted, however, that this value was obtained using lead of only one composition and measurements at only two temperatures. The work of Aust and Rutter3"' on the effects of tin, silver, and gold on grain boundary migration in zone-refined lead in the temperature range from 320" to 200°C, as well as the work of Bolling and Winegard34 on the effect of silver and gold on grain growth in zone-refined lead, shows that the measured activation energy is markedly dependent upon the kind and amount of solute present. Gifkins' work does not permit evaluation of the effect of the 8 ppm of impurities other than oxygen present in his specimens. One incidental point: the symbols used to designate the experimental points of Fig. 6 appear to be in incorrect order in the figure caption. As the caption is printed, it would indicate that larger grain sizes were obtained after annealing at 47°C than at 100°C, which does not agree with the text (point M, p. 1019). Finally, it seems clear from Gifkins' results that any serious attempt to determine whether grain boundary migration and grain boundary sliding during creep occur with the same activation energy, as Gifkins suggests and McLean rejects, must take into account the effects of impurities on these two processes, Although the work of Weinberg35 indicated that adding small amounts of copper, iron and silicon to aluminum did not affect the grain boundary shear behavior, it should be noted that his starting material contained approximately 60 ppm of impurities. Gifkins' results indicate impurity effects at an impurity level of 8 ppm, suggesting strongly that the most significant impurity range to be investigated lies substantially below that value. R. C. Gifkins (author's reply) — As Drs. Aust and Rutter suggest, the results under discussion may have to be reinterpreted in the light of their own work on grain boundary migration, which was not available to me when the paper was written. Because of their work, Aust and Rutter attach more importance than I did to the activation energy for grain boundary migration during annealing (7.5 kcal per mol) obtained from a "direct" plot of log-rate against the reciprocal of absolute temperature. At the time it was obtained, this value seemed rather low, although it was similar to the value obtained by Bolling and Winegard.36 It was then, and still is, difficult to accept this value because of the low value of the index in the power law for grain growth, which seemed to indicate the influence of impurities. It was also concluded that the low value of the activation energy might have arisen from the manner of selecting rates of grain growth which were truly comparable at the two temperatures. There were many other indications in these experiments and those on recrystallization during creep3? that an impurity, probably oxygen, was of importance. The model for grain-boundary migration which Lucke and Detert had proposed was an obvious possibility and its use yielded an activation energy for boundary migration during annealing of 20 to 25 kcal per mol.

Jan 1, 1961

By Frank Speller

WE are here to honor again the memory of Henry Marion Howe, one of the foremost metallurgists of his time, and it is indeed a great privilege to be called upon by the Board of Directors of .this Institute to give the memorial address this year. Professor Howe started active investigation of corrosion of iron from a metallurgical standpoint in 1887, and made several important contribu-tions to the subject from 1895 to 1908.(1) ? The papers named in the bibliography are only a few of his valuable papers, but in all his works he sets a high standard of scientific accuracy, together with a clearness and power of expression rarely equaled in engineering literature. There-fore it seems appropriate on this occasion to review the work on corrosion of this distinguished gentleman and then endeavor to make a brief inventory of what has been accomplished since his time. Howe saw the beginning of the steel industry in America and before he died (May 14, 1922) witnessed it develop to a production of 45,000,000 tons per year. He was naturally very much interested in the infant industry and was quick to see the importance of the question of corrosion. It was my privilege to discuss the subject of corrosion frequently with Professor Howe at various times from 1905 to 1908; in this, as in other metallurgical problems, he sought the truth without bias and always insisted on proving an opinion or conclusion before accepting it. We should remember that when Howe started his investigation of corrosion, in 1887, steel was rapidly supplanting wrought iron. Certain papers in the early eighties (now forgotten) claiming much greater durability for wrought iron than for steel aroused Howe's interest. He could not reconcile the statement that steel was intrinsically and incurably less durable than wrought iron with the continued and widening use of steel,

Jan 1, 1934

ASSETS CAPITAL ASSETS Equity in United Engineering Society's Land and Buildings $486,792 79 Library 40,000 00 $526,792 79 INVESTMENTS Jas Douglas Fund-Schedule #2 $ 99,966 40 Life Membership Fund-Schedule #3 9,415 63 R W Hunt Medal Fund-Schedule #4 7,489 09 116,871 12 INVENTORIES Paper Account .305 10

Jan 1, 1923

Organization Place Date 1917 American Institute of Architects Philadelphia., Pa. Dec. 26-29 American Society of Mechanical Engineers New York City. Dec. 4-7 American Mining Congress State Chapter Phoenix, Ariz. Dec. 26-29 1918 American Society of Civil Engineers New York, N. Y. Jan. 22-25 American Institute of Mining Engineers New York, N. Y. Feb. 18-21

Jan 12, 1917

By A. U. Seybolt, D. H. Haman

The rate of oxidation of the lowest nitride of chromium, Cr2N, was measured to be equal to the rate of oxidation of chromium metal. It was found that, while the presence of Cr2N in chromium does not affect the oxidation mechanism, a long exposure at high temperature affects the morphology of Cr2N in chromium, causing a massive internal nitriding along chromium pain boundaries. Marker expen' -ments showed that the rate of oxidation of Cr2N layers on chromium is determined by the rate of chromium diffusion through Cr,03. The rate of formation of Cr2N is determined by diffusion rate of nitrogen through Cr2N. This rate at 1000°C is around thirty times faster than the rate of oxiahtion. Evidence is presented which suggests that nitrogen from the air reaches the chromium through the Cr2O9 by migration through pores or cracks rather than by a diffusive process. IT has long been recognized that, when chromium or alloys containing substantial amounts of chromium are oxidized in air, some chromium nitride (Cr2N) is formed under the oxide scale. Although the presence of this nitride layer has often been described, there appears to have been no systematic study of the role played by the nitride during the oxidation process. Indeed, there have been conflicting re-ports'92 on the kinetics of oxidation of chromium and chromium alloys in air and in oxygen. However, it is now well-established'-5 that the rate-controlling process during the parabolic oxidation of chromium to Cr2O3 is chromium-ion diffusion through Cr2O3. Because of the importance of chromium-containing alloys as oxidation-resistant materials, it seemed desirable to investigate the behavior of chromium during oxidation with and without the presence of chromium nitride. Since a semicontinuous Cr2N layer forms relatively early during the oxidation of chromium in the air, chromium atoms must either pass out of or through the Cr2N layer to become incorporated in the growing Cr2O3 scale. Therefore, it seemed desirable to examine the oxidation behavior of the pure nitride. MATERIALS AND EXPERIMENTAL PROCEDURE The chromium used in this investigation consisted of slices of an ingot made from "five-nine" iodide chromium which had been argon-atmosphere melted in a Y2O 3-stabilized ZrO2 crucible in an induction furnace. The only impurity of any significance was 625 ppm of 0, which was usually reduced to a microscopically invisible amount by hydrogen annealing at 1400°C. However, one sample of chromium was used with the as-cast oxygen level as explained below. The samples were used after abrading through 600 Sic paper and then washing in toluene and alcohol. Both nitriding and oxidation experiments were performed in a vertical tube furnace connected to a glass vacuum system. 'This system was equipped with pressure measuring instruments for the range of 10 p to 1 atm, and a cartesian-diver pressure-control device was used in conjunction with a needle valve to allow control of pressure in the range of about 10 to 760 mm. The nitrogen or hydrogen gas was purified by passing through hot copper chips at 600°C, anhydrous calcium sulfate (Drierite), and liquid nitrogen. Oxygen gas was dried through the Drierite column and a dry-ice trap (-78°C). Changes in specimen weight were followed by a Pyrex helix used in conjunction with a cathetometer which could reproducibly be read to +0.001 cm, yielding an accuracy of about +0.2 mg. The spring was maintained in the cool upper part of the furnace tube where the temperature did not rise above about 35°C. The nitride in equilibrium with metallic chro-

Jan 1, 1964

By W. Shockley

THIS lecture can best begin with a statement of the chief conclusion: The metallurgical industry will find profit in supporting fundamental research on dislocations. This support should be done both in their own laboratories and in universities. My lecture consists of an exposition of the basis for this conclusion. The experience on which I base it is drawn largely from two fields in solid state physics—one field is transistor electronics and the other is dislocation theory. At present the relationship of solid state physics to technology is different in these two fields. In electronics without question, the physics has led the technology. In metallurgy, on the other hand, the technology in the form of metallurgical art is far ahead of the fundamental science. In transistor electronics, physics has suggested and can still suggest previously unachieved combinations of matter that will have new and useful properties; that is, the physicist can make specific predictions. The physicist can also have some confidence that the predicted devices will actually come into existence in a matter of months or years and that they will live up to the predictions. In metallurgy, the physicist cannot to a comparable degree make predictions and have the same hope that they will lead to something new and valuable. There are a number of reasons for this difference. The first is simply historical. Transistor physics is young. It may be regarded as dating from the announcement of the transistor, in which case it is about four years old, or from the first real control of semiconductors as materials (this was accomplished largely by metallurgists, by the way) in which case it is about ten years old. Metallurgical art, on the other hand, is thousands of years old. There is no doubt that the advance of this art has been and will be hastened by a good fundamental understanding of the quantum theory of atomic phenomena. It, is too much to expect, however, that theory will soon catch up with the lead that practice has gained in a thousand years, and that theory will then point out specific pathways to better materials. It seems more probable that modern atomic theory will serve to interpret and organize information much as thermodynamics has done through phase diagrams. In this lecture, I shall emphasize an important feature common to both solid state electronics and to metallurgy. This common feature is the harmonizing principle that justifies discussing electronics and metallurgy as related topics in solid state physics. In both cases the important properties of the materials arise from imperfections. By imper- fections I mean deviations of the materials from perfect single crystals. The imperfections may be of many forms. From the point of view of utility they may be either good or bad, and a given type may be good or bad depending on circumstances. The technical material of my lecture will be divided into two parts. The first will be chiefly concerned with four types of imperfections in germanium crystals. The control of these imperfections makes possible the fabrication of useful electronic devices. A good example of such control is the junction transistor, which I shall discuss from this viewpoint later. The junction transistor, as some of you may have heard, can be used as an amplifier of electrical signals and in a number of respects surpasses what has hitherto been achieved with vacuum tubes. The second part of my technical material will be concerned with dislocations. For about fifteen years the theoretical physicist has had dislocations in mind as the most important kind of imperfection in metals. He has, however, until recently had experimental material of a highly speculative nature to back up his assertions. I am fortunate in the timing of this lecture to be able to describe some recent results that put dislocations on a far more definite basis than has been the case in the past. In fact there are now some experiments which reveal the characteristic properties of dislocations almost as clearly as experiments in transistor physics reveal the properties of holes and electrons, properties that I shall soon describe. It is this advance in the status of dislocations that emboldened me to make my initial assertion that the metallurgical industry will profit from supporting fundamental research on dislocations. Transistor Electronics In order to discuss imperfections in semiconductors, it is necessary to visualize a reference condition that may be regarded as perfect. In the cases of silicon and germanium, which find application in transistor electronics,' the perfect structure is the diamond structure shown in Fig. I. In this structure, each atom is surrounded by four neighbors with which it forms four covalent or electron-pair bonds. These bonds use all of the four valence electrons possessed by each of the silicon or germanium atoms. The electronic structure of the crystal is thus complete and perfect. A crystal of silicon or germanium with a perfect electron-pair bond structure would be an insulator, In order for electrical conduction to occur, it is necessary for imperfections to arise in the electronic structure. In this lecture, I shall discuss four possible imperfections whose symbols and relationships are indicated in Table I. We shall consider first, as an example, a crystal of silicon containing an arsenic atom as an impurity.

Jan 1, 1953

By R. P. Laforce, ZJ. R. Low, A. M. Turkalo, D. F. Stein

The interaction of the crlloying eletnenls, nickel and chromium, with the impurity elements, antimony, pIzosphorus, tin, and arsenic, to producse reversible temper brittleness in a series of high-purity steels containing 0.40 wt pct C has been investigated. The alloyed steels contained approximately 3.5 pcl Ni, 1.7 pct Cr, and 0.05 to 0.08 pct of the particular irnpurity to be investigated. Susceptibility to teirlper embrittlement was measured by comparing the notched-bar transition temperature of each steel after quenching from the final temper and after very slow cooling (step cooling;) following the final temper. A plain carbon steel without alloying elements, bu/ ud/h 0.08 pel Sh, does not embrittle when step-cooled through the emzbrittling range of temperatures. The same embrittling treatment, applied to a steel with about the same antinzony content but with nickel and chvonziunz added, causes a 700°C increase in transition temperature. If chromium or nickel is the only alloying element, the increase in transition temperature is only 50%, again with antimony present. A carbon-free iron containing nickel, chromium, and antimony shou~s a 200°C shift in transition temperature for the same thermal treatment. Specific alloy-impurily interactions are also observed for the other impurity elements, phosphorus, tin, and arsenic. Additional investigations involving electron microscopy, trzicrohard-ness tests of vain boundaries, minor additions of zirconiutn and the rare earth and noble metals, nzainly with negative results, are also described. HE particular type of embrittlement investigated is that which is encountered in alloy steels tempered in the temperature range from about 350" to 525'C or slowly cooled through this range of temperatures when tempered above this range. This type of embrittlement is sometimes called reversible temper brittleness to distinguish it from the embrittlement indicated by a minimum in the room-temperature V -notch Charpy energy vs tempering-temperature curve encountered in the range 28 0" to 350°C. Temper brittle-ness seriously restricts the use of many alloy steels since it precludes tempering or use in the embrittling range of temperatures and may significantly raise the ductile-brittle transition temperature of heavy-section forgings and castings tempered above the embrittling range, since such sections cannot be sufficiently rapidly cooled after tempering to avoid embrittlement. The very voluminous literature of temper brittle-ness up to about 1960 has been reviewed by woodfine' and LOW.' Of particular significance to the present investigation was the demonstration by Balajiva, Cook, and worn3 that high-purity Ni-Cr steel does not exhibit temper brittleness and the subsequent detailed and systematic study by Steven and Balajiva~ of the effect of impurity additions on the susceptibility to embrittlement of Ni-Cr steels. Steven and Balajiva showed that, of the impurities which may be found in commercial steels, Sb, As, P, Sn, Mn, and Si could all produce temper brittleness in a high-purity Ni-Cr steel. The principal purpose of the present investigation was to study the effects of particular alloy-impurity combinations on susceptibility to temper embrittlement. The steels used were high-purity 0.30 to 0.40 wt pct C steels containing 3.5 wt pct Ni and 1.7 wt pct Cr, separately or in combination. The susceptibility of these steels was then determined when approximately 500 ppm by weight of antimony, arsenic, phosphorus, or tin were added as an impurity. The melting, casting, and forging practices used in the preparation of the materials investigated are described in Appendix A. Table A-I in this appendix shows the analysis of all steels to be discussed. The steels were produced as 20- or 2-lb heats. The smaller heats were used after it had been demonstrated (see Appendix B) that a small, round, notched test specimen could be used to measure the shift in the ductile-brittle transition temperature caused by temper brittleness with about the same result as that obtained by Charpy testing. HEAT TREATMENT Unless otherwise noted, all steels were tested for embrittlement in the tempered martensitic condition. A typical heat treatment for a 0.40 C, 3.5 Ni, 1.7 Cr steel was: 1 hr at 870"C, in argon, quench into oil at 100"C, quench into liquid nitrogen, temper 1 hr at 625"C, and water-quench. The warm oil quench was used where quench-cracking was encountered; otherwise the initial quench was into room-temperature oil or water. For other compositions austenitizing temperatures were 50°C above Acs with the remainder of the thermal cycle the same. Steels in this condition, with no further heat treatment, are designated as non-embrittled. The above quenching and tempering cycle for the 0.40 pct C steels resulted in as-quenched hardnesses of 48 to 53 RC and as-tempered hardnesses of 24 to 31 Rc except in the case of the plain nickel or plain carbon steels. In these, the as-tempered hardness was as low as 80 to 90 Rg. No attempt was made to adjust the tempering temperature to obtain the same hardness in ali steels since it was felt that a uniform thermal cycle was more important than exactly equivalent hardness values. Pro- the standard quench and temper described above, the standard embrittling treatment was "step-cooling". For this the thermal cycle was: 593"C, 1 hr; furnace-cool to 538"C, hold 15 hr; cool to 524"C, hold 24 hr; cool to 496"C, hold 48 hr; cool to 468'C, hold 72

Jan 1, 1969

By Wilford L. Stork

Certain influences of oxygen on iron have been known for many years and it has always been considered one of the worst enemies of the iron and steel founders. Nobody had a good word for it, hence little was done to make use of this oxygen. In all the fields of foundry practice, the desideratum was "melt without oxidation of the metal." In the consideration of the influence of oxygen on cast iron, we must not confuse this condition with oxidized iron caused by poor melting conditions, due to a high bed, heavy charges, low coke ratio, excessive melting rate, high blast, or poor charging. It is admitted that oxygen absorbed by iron melted under these conditions has a deleterious effect on the properties of the iron. The writer has had experience both in the melting under such poor conditions and in remedying these bad conditions and considers the product far inferior to iron melted under normal conditions. As stated by Dr. Richard Moldenke,l such iron has a higher melting point and high combined carbon, is sluggish, and contains slags and oxides in solution in the liquid, causing slag inclusions and gas occlusions, 'thus producing defective castings. This oxidized condition cannot be counteracted or removed by any of the known deoxidizers; it can be remedied only by proper melting conditions. Such iron is redly burned, whereas the iron considered in this paper was melted under normal conditions with moderate blast, correct bed height, light charges of iron, and low coke consumption and is not in this category at all. In 1914, the late J. E. Johnson, Jr., startled the metallurgists of the . world when he published his results on the advantages of oxygen on cast iron.2 His work is so convincing and so logical, in spite of the common and well-established notions on the subject, that nobody has been able to refute a single argument. Such an eminent authority on iron and steel metallurgy as Prof. H. M. Howe has accepted the work in all its details in his latest book.3 The work of J. E. Johnson, Jr., has revolutionized the metallurgy of cast iron and it seems apparent that all future work must include an oxygen determination just as we include silicon, sul-

Jan 1, 1920

By F. L. Sizer

The mining regulations of British Columbia and Mexico present some features which might well be copied in the United States, if we are to have a complete revision of the laws governing mining titles. 1. First and foremost is the "squarc" location, which would mean the abolition of extralateral rights. This is a condition in both of the countries above named which has seemed to work no hardship upon any one, and certainly the limitation of underground rights by vertical planes through all lines makes a locator's rights clear. In view of the long and costly litigation which has involved so seriously many of our most important mining districts, it would seem to be the part of wisdom to avoid a repetition of similar trouble on titles of lode mining claims, by the enactment' of a law similar to that in force in British Columbia. Objections have been raised by .representatives of English companies to the investment of large amounts of money in mining operations in the United States, because of the insecurity of title under the 'present apex law; and the statement has been made to me personally by one of the largest English operators, that he would .never again consent to the purchase of mines in the United States, preferring Mexico with all its revolutionary troubles to the danger of encroachment upon his underground rights by an unscrupulous neighbor. Without going into further argument as to the desirability of the I(square location," it should be sufficient to say to those who are inclined to "let well enough alone" and still stick to the "law of the apex" that there have never been any serious objections raised to this feature of the square location in either British Columbia or Mexico. There are well founded and logical reasons for abandoning the doctrine of extra-lateral rights since it is so difficult of interpretation; the most natural substitute being a law similar to that of British Columbia, giving to each locator an area 1,500 ft. square. I would advocate the right to locate adjoining claims of equal extent on either side of the discovery claim, on the strike of the lode, subject to a seasonable requirement in the matter of work upon them; and in the case of a vein dipping flatter than 45' from the horizon, or in case of a

Jan 1, 1915

By P. Barnes

Several statements have been made to the Institute, somewhat detached from each other, as to the cost of some parts of these works, but they have not included any extended description of the buildings or machinery. The general plan of the work connected with the water supply differs, in some important details, from that which has been common either in the Pittsburgh district or elsewhere, and a somewhat extended description may be of interest to the Institute, in connection with a note of the cost of the work. The plan as a whole, and nearly all the important details, were developed by Mr. William P. Shinn, C.E., the general manager of the Company. The immediate and responsible charge of the work was in the hands of Mr. John C. Lewis, C.E., to whom had been committed all the work of this general description, including the laying out of the whole of the foundations, the erection of the buildings, and the grading and laying down of the entire railroad system. The continuous operation of the machinery and other fixtures of these waterworks, for more than three years, has fully demonstrated the correctness and econonly of the plan adopted. No casualties of any moment have befallen the apparatus, and no improvements have been suggested as important except that the gate at the river end of the conduit should have been made more completely water-tight, so that the whole length of the conduit could be pumped out dry without resort to any temporary dam in the conduit itself. In general terms the works of the Edgar Thomson Company are situated on a plateau, about 52 feet above the low-water level of the Monongahela River, and about 2000 feet from its bank. The site of the works is bordered on one side by Turtle Creek, a small stream which drains a considerable area of coal mining territory. This creek is about 100 feet from the group of buildings which have been erected, but it flows into the Monongahela River at a point, about 1200 feet further up than that selected for the entrance to the waterworks conduit. It was ascertained by analysis that the water in the creek contains an important percentage of sulphate of lime, while the water of the river is of unusual purity, in respect of any salts

Jan 1, 1879