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By S. V. Krishnan, I. Iwasaki

In the upgrading of finely disseminated iron ores, selective desliming is the critical step that must be controlled to achieve efficient flotation. A prerequisite for selective desliming is a properly-dispersed pulp; sodium silicate is commonly used as a dispersant. The mechanism by which sodium silicate acts as a dispersant in the presence of calcium ions was examined by streaming potential measurements, settling tests, abstraction density determinations, selective flocculation tests, and scanning electron microscope observations. The study established that calcium silicate precipitates on the mineral surfaces dispersed the pulp. Although sodium silicate was a nonselective dispersant, the addition of corn starch aided flocculation of goethite over quartz at low silicate additions, but became ineffective at higher silicate levels. A model is presented to explain the dispersant mechanism of sodium silicate in the presence of calcium ion for selective flocculation of iron ores.

Jan 1, 1983

By Brison Robertson, W. P. Fishel

THE carbide-forming tendencies of the various steel-alloying elements, or their affinities for carbon, is a subject that has received considerable attention, but little more than a probable arrangement of the elements as to their carbide-forming tendencies has been proposed. The physical properties of alloy steels depend upon the relative proportions of the elements present and their combinations. One important phase of this subject is the distribution of carbon between the various elements present. The distribution of carbon between iron and other elements evidently will depend upon: (I) the affinity of each for carbon; (2) the relative atomic masses of the elements present; and (3) the possible formation of compounds between the alloying elements and iron and between the elements themselves. In ternary steels the case is simplified, especially in systems in which the element and iron form no compounds. In such systems iron and the alloying element are competing for the carbon present. In this work the distribution of carbon between titanium and iron has been studied by measuring the relative amounts of iron carbide and titanium carbide present in a series of annealed steels in which the ratio of titanium to carbon extended from 0.527 to 4.61. EXPERIMENTAL PROCEDURE Ten Fe-Ti-C alloys, weighing about 250 grams each, were prepared by melting under a vacuum, in an induction furnace, Armco iron, carbon-free ferrotitanium (25 per cent Ti), and pure carbon. Vacuum melting prevented the formation of titanium oxides and nitrides, which would complicate the problem. The melts were made in graphite crucibles lined with sintered magnesium oxide. The ingots were cooled in the furnace under a vacuum and were then completely annealed at 950°C. The determination of the amount of titanium carbide present was based upon the established insolubility of titanium carbide in boiling dilute (I :4) sulphuric acid, and the complete solubility of free titanium and titanium-iron compounds in this acid. High-carbon ferrotitanium, which had been treated to remove free Ti and Fe, was found to be completely insoluble in the acid; and the carbon-free ferrotitanium used in making the alloys was found to be completely soluble. Others 1,2 have reported the insolubility of titanium carbide in sulphuric and hydrochloric acids. Turnings from the ingots were digested with boiling sulphuric acid (1:4) until all action had ceased. The carbide residue was filtered off and analyzed for titanium, and in some cases for carbon. This represents the titanium that was united with carbon. The filtrate from the carbide residue contains the portion of the titanium that wasin solid solution in the ferrite. Titanium

Jan 1, 1944

By W. B. Morrison

Anderson, King, and Spreadborough present detailed evidence to show what ~aldwin~' has already pointed out, that, over a relatively small grain-size range (Ad"1/2 ^ 10 mm-'I2, d is average grain diameter), yield point data can fit a number of relationships. Part of the difficulty in obtaining data which reflect only the effect of change in grain size on yielding arises from the fact that in varying the grain size, even though great care is taken, other structural changes are almost certain to occur. In iron alloys, these changes may consist of variations in subgrain size, grain boundary ledge density, and degree of carbon and nitrogen segregation at grain boundaries, all of which are difficult to detect and which may affect yielding, primarily through their effect on dislocation generation. Because of the inherent inaccuracy associated with yield point measurements there is little point in using relatively complex equations to fit data, as was done by Anderson et mnl., rather than the simpler, widely used Hall-Petch equation. In compiling their table of data, it is surprising that they did not include results from certain low-carbon steels,31 in which, as illustrated in Fig. 2, the grain-size range is very much larger than in their Armco Iron. The very fine grains in these steels were obtained by a thermomechanical process. Examination by electron microscopy showed that the grains were separated by high-angle boundarie and contained only an occasional subboundary. The data from these steels obeyed the Hall-Petch equation, and it was shown quite conclusively that they did not fit a d-l or (1-lJ3 relationship. Obviously, a much wider range in grain size than used by Anderson et al. is desirable if we are to determine the true relation between lower yield stress and grain size.

Jan 1, 1969

By George E. Kruger, William F. Butler

The less developed nations maintaining a free enterprise economy (to which this chapter is addressed) have real and substantial opportunities to lay a foundation for general economic progress by using their mineral resources. Most of these nations have mineral resources which could be developed. By seizing these opportunities, nations seeking rapid economic development can secure a source of foreign exchange earnings to finance the imports needed for growth and, at the same time, increase the technical knowledge and well-being of an important part of their population. History clearly shows the manner in which most of the currently industrialized nations have used mineral resources to support their development. Indeed, few nations have managed to achieve a high level of income without a firm base of mineral resource development. The main exceptions appear to be the Netherlands, Switzerland, Denmark, and New Zealand, and the last two have based their prosperity on a highly efficient agriculture. Economic growth in the United States, the United Kingdom, Canada, France, Germany, and Russia was importantly based on the use of indigenous mineral resources. Despite this record of accomplishment through mineral development, many of the currently less developed nations are not taking advantage of the opportunities available in the mineral field. Restrictive laws or practices in many such nations operate effectively to prevent development of mineral resources. This failure to grasp real opportunities for development is based on a series of arguments that the mineral field offers few substantial and attainable advantages. Among these, the following propositions appear the most important:

Jan 1, 1964

Papers in Classes A-Metal Mining, B-Milling and Concentration, H-Industrial Minerals, and I-Mining Geology are distributed in MINING TECHNOLOGY, which is issued every other month. Papers in Classes C-Iron and Steel Division, D-Nonferrous Metallurgy and E-Institute of Metals Division are distributed in METALS TECHNOLOGY, which is issued twice quarterly. Papers in Class G-Petroleum Division are distributed in PETROLEUM TECHNOLOGY, which is issued every other month. TECHNICAL PUBLICATIONS in Classes F-Coal Division, J--Mineral Industry Education Division, K¬-Mining Administration, and 1-Geophysics, are issued as separate pamphlets. Contributions are papers that when printed or mimeographed are available but only on request.

Jan 1, 1944

By F. D. Rosi

IT was recently shown1 that slip bands can be observed in bent germanium crystals after deformation, by means of etch pits along the slip traces. It is the purpose of this note to show how chemical etch pits can also be usedto examine the appear- ance of slip bands in silicon, as well as other deformation markings. A 30 ohm-cm, p-type single crystal bar, 2x1/4x1/8 in., was plastically bent at approximately 1200°C in a vacuum of 1x10-5 mm Hg. The axis of the crystal was coincident with a <III> direction, and the surface normal to the axis of bending was within 4" of a (110) plane. Prior to the deformation, the (110) surface was mechanically polished with

Jan 1, 1958

By Henry S. Brown, Jean E. Tilden

Pyrite, pyrrhotite, chalcopyrite, and sphalerite from deposits distributed within the Piedmont and Blue Ridge provinces of North Carolina and adjacent areas were examined by atomic absorption spectrophotometry for cobalt, nickel, manganese, lead, tin, chromium, molybdenum, and gold. The ore samples were also examined petrographically. Cobalt and nickel, in general, enter pyrite and pyrrhotite rather than chalcopyrite and sphalerite. Manganese generally enters sphalerite rather than the other phases where an alternative is possible. The presence of tin in sulfide minerals was noted in a group of deposits east of the known occurrences of tin oxide (cassiterite) in the Kings Mountain belt, which may indicate the presence of a more extensive tin belt in the southeastern Piedmont than was previously recognized. Pyrrhotite from a group of four deposits in Jackson and Clay Counties, North Carolina, differs from pyrrhotite from other Ducktown-type deposits in having cobalt/ nickel ratios less than one, finer grain sizes, and colloform texture. These differences suggest that that this group of deposits has had a history different from that of the other Ducktown-type deposits studied. No significant conclusions could be made based on the distribution of lead, chromium, molybdenum, or gold.

Jan 1, 1975

By T. Egleston

THE ores of mercury of North California are composed of metallic mercury and cinnabar. They are found in serpentine, and are very often associated with chalcedony, in masses more or less irregular, often concentrated enough, however, to furnish ores yielding from three to ten per cent., and sometimes richer. This deposit makes its appearance in Vallejo where it has been worked. North of here the mines are more developed. Most of the quicksilver mines, how¬ever, are situated in Sonoma and Napa Counties. On its outcrop the serpentine rocks have become decomposed, and have often been washed away to a considerable depth, so that in many cases in their neighborhood, what is apparently nothing but ordinary dirt, will frequently contain from two to three per cent. of metallic mercury, with but a trace of cinnabar, in which case, as at the Sonoma mine, it is made up into adobes and distilled. Such material does not require to be mixed with dirt to be made into adobes. Very often, also, the outcrop of the rock, where it is not decomposed, is filled with metallic mercury, so that by striking a pick into it, as at the Rattle-snake mine, a pound or more of mercury at a time will sometimes spurt out. Such rock as this is found in several localities in every stage of impregnation, and usually makes very rich ore. There is generally, however, very little of it, and it is found only in the first workings ; the ore in depth is always cinnabar. At the Rattlesnake mine near Pine Flat, where large quantities of metallic mercury are found, the rock contains so much petroleum that it has been necessary to make special arrangements to burn the carbides of hydrogen, since the distillation of the petroleum causes an extra quantity of poor soot to be formed in the condensation-chambers. At the Geysers the ore is associated with large quantities of sulphur and gypsum, so that in a hand specimen there is often more sulphur than cinnabar, which is a serious impediment to working, especially for the modern style of furnace with iron condensers, and causes so much soot to be formed that it has been known to penetrate as far as the blower, and to so completely clog it as to prevent its revolution. The ore coming from the mine is more or less hand-picked. In one or two cases attempts have been made to treat the poorest, and especially the very fine ores, mechanically as at the California works.

Jan 1, 1875

By G. S. Rice

With so tremendous a subject, an attempted review of the coal situation of the world in a short talk must necessarily be of a sketchy character. It is hardly necessary to tell a body of engineers that had it not been for nature&apos;s gift of coal the material side of modern civilization would never have reached its present status. On the other side, it is regrettable that it was a byproduct of coal, T. N. T., which made possible Germany&apos;s initial success in this war, because that country had an enormous development of manufacturing plants that could be immediately utilized to make this destructive agent: One sometimes hears the casual remark that when the coal of the world is exhausted we shall use electricity; but, of course, electricity is ordinarily only a means of transforming and transmitting energy derived from fuel or water power, and chiefly from coal. It is true, we have much undeveloped water power, but it is more or less remote from &apos;the, centers of industry; and when all shall have been developed it will not begin to supply the power requirements of the world. It is, however, reasonable to expect that before the world&apos;s supply of coal shall be exhausted, methods will have been discovered of harnessing other forces of nature, such as the tides, or the energy emanating from the sun. Petroleum and natural gas naturally come to mind, but the days of both, as fuel, appear to be numbered, although the products of petroleum, if economically used, doubtless will be available for internal-combustion engines, automobiles, trucks, and boats for a long time, provided the reckless use of crude petroleum as an ordinary fuel is stopped. The products of petroleum are too valuable to mankind for such waste to be permitted. The civilization of the world, therefore, appears to rest, and, so far as can be seen, will indefinitely continue to rest, upon coal. COal Resources of the World According to the compilation made by the geologists of the principal countries for the 12th International Geologic Congress, held in Canada

Jan 1, 1918

By William Kent

DURING the discussions at the Philadelphia meeting in February last, † several speakers expressed their doubts of the general accuracy of chemical analyses of steel made by "iron works chemists," and especially of determinations of manganese. Since the meeting,. the discussion of the "practical value of chemical analyses" has been continued at some length in the columns of the Iron Age. †Transactions, vol. ix, p. 529.

Jan 1, 1882

By R. W. Hunt

The old plan was to increase every part of a rail much in the same proportion. But each part should be in proportion to what it ha.; to do. The head should be deep in proportion to tile amount. of traffic and the lowness of the rate of interest on its cost. The body need only he strong enough to carry the head after it is well worn down, and that deperlds on the weight of the machinery, and in the case of steel has little to do with the volume of traffic, except SO far as that affects weight of machinery. Ad on most railroad systems, the same niacliinery is used on main lines with heavy traffic, and bra11ct:es with light, I suggested in 1874 that each systern adopt the same body of rail for both, and make the head deeper on the main lines, shallower on the branches. This plan was adopted on the Pennsylvania Railroad. Bandberg seems to recognize this in his patterns of 1878. E. W. HUNT, TRoy, N. Y.: Again Dr. Dudley preaents to our cousideration a series of most carefully conductetl experiments, and ~llile I fully appreciate the labor and thought this work has cost him, I must still hesitate to accept his deductiono. This paper dilliirs from the previous one in that it denls esclrieively with the wearing qualitiei. of steel rails. Dr. Dudley gives his reason for this change in the following statement: " With the improvement in maintenance of way which has characterized the Pennsylvania Railroad during the last five or six yearn, the remova1 of rails from the track from the first two of these causes (i. e., broken and crushel), has, if I am right, quite notably diminished. This certainly is true with regard to broken rails. And if, as time advances, the number of crushed rails shall diminish, both because of the continued improvement in maintenance of way before referred to, and because, owing to improved and better methods at the steel works, there are fewer crushed rails caused by physical defects in the steel, the question of the wearing capacity of steel rails obviously becomes the allimportant one." Certainly the condition of the roadhd has much to do with mils brealring, crushing, and wearing. If the Pennsylvania and other railroads have done and are doing their part, Dr. Dudley oourteously admits that the steel works have performed part of theirs. But as far as I am informed, the formulas which they have used have been and are still quite wide of the one he continues to recommend. The rails which are not breaking or crushing to so great an extent as formerly, contain higher percentages of both carbon and manganese.

Jan 1, 1881

By Otto F. Pfordte

The great advance of the last twenty years in the specialization, delicacy and efficiency of ore-concentrating apparatus calls for a finer system of testing both the qualities of ores and the operations of machines in this department. In amalgamation, lixiviation and smelting, the daily employment of physical and chemical tests has been recognized as necessary, and the cost of the necessary laboratories and employees is cheerfully paid. But while much progress has been made in concentration (due, in a large degree, to the study of the subject in our technical schools), it is still too common in actual practice to follow the loose old method of roughly estimating, once for all, that a given ore " concentrates x tons into one," and resting on this assumption so long as that ore continues to be treated, while assays of the tailings from concentration are made from time to time, without exact determination of their quantity. The first step toward accuracy of control must be a more frequent and precise measurement of the quantity of concentrates from a given operation. This should be expressed in pounds per unit of one ton; and the variations shown in frequent determinations will furnish a constant check upon the character of the ore and the performance of the apparatus. But this is only a part of what should be constantly and systematically done to insure the best work upon a material which must vary continually, even though it come from one mine only. If, in any mill, appropriate laboratory-tests were made at least once a week, the labor and expense involved would be amply repaid by increased knowledge and control of the current operations. A small testing-laboratory, provided with a few gold-pans;

Jan 1, 1902

By John Fritz

THE John Fritz Medal was presented to Ambrose Swasey of Cleveland, Ohio, in the Auditorium of the Engineering Societies Building, in New York, on April 23. Charles F. Rand, Chairman of the Board of Award, presided and, after speaking very briefly of Mr. Swasey, whose friend he has been for a great many years, ,introduced Gen. William Crozier, formerly Chief of Ordnance, U. S. Army, who spoke most entertainingly of, Mr. Swasey&apos;s accomplishments in designing and manufacturing instruments of precision, particularly for the use of artillery in range finding: Dr. William Wallace Campbell, Director of the Lick Observatory, and President of the University of California, described Mr. Swasey&apos;s, contribution to astronomical advancement by his notable development of the largest telescopes in this country.

Jan 1, 1924

By Sweetser, Ralph A

AT the fall meeting of the Iron and Steel Division, Oct. 4, 1934, in New York, a symposium was held on Slag Control in the Making of Iron and Steel. The chairman was J. H. Nead and the vice chairman, G. B. Waterhouse. The latter presided at both morning and afternoon sessions. The papers and discussions were presented in the order in which they appear on the following pages. To meet space requirements, much of this material has been considerably condensed. CONTENTS Slag Control and the Blast Furnace. By Ralph H. Sweetser. (With dis¬ cussion.) I Slag Control in Rimming Steel. By L. F. Reinartz 5 Slag Control Applied to Low-carbon Steel. By Frank G. Norris 9 Discussion on both papers 11 Slag Control for Basic Open-hearth High-carbon Steel. By W. J. Reagan. (With discussion.) 14 Slag Control for Recarburized Rail Steel. By A. P. Miller and T. S. Washburn. (With discussion.) 18 Slag Control for Alloy Forging Steel. By A. L. Feild. (With discussion.). . . 24 Slag Control for Alloy Forging Steel. By R. C. Good 27 Slag Control in Acid Open-hearth Steel. By Francis B. Foley. (With dis¬cussion.) 29 Slag Control for Basic Electric-furnace Steel. By H. F. Walther. (With discussion.) 31 Physical Testing of Slag. By A. B. Kinzel. . 40 General Discussion 41

Jan 1, 1935

By H. B. Goodrich

In considering historically oil development in Oklahoma, it must be recognized that basic evolutionary factors interlock and have an effect in common throughout the whole oil industry, regardless of locality or minor problems. Oklahoma, as the third in rank of oil-producing states (Texas being first and California second in production for 1929) has, like the rest, advanced to at least a partial recognition of the words, "Conservation," "Unitization," "Curtailment," "Prora-tion," and especially "Cooperation." Whether through altruism (of which there have been examples) or by exercise of good business common sense, Oklahoma operators realize that the oil business can run itself by cooperative action for the good of all. In this long-continued period of overproduction, Oklahoma has brought the advancing output down to limit of market requirements at least temporarily. Sources of Statistical Data For this paper, figures published by four recognized authorities were consulted. Between themselves these vary only a negligible per cent, in their totals. To be consistent, and on account of earlier availability the estimates published by the Oil and Gas Journal are mainly used herein, supplemented from other public and private sources. General Oil ProdCction in Oklahoma In 1927 Oklahoma&apos;s peak of all years was 276,022,024 barrels. In 1928 Oklahoma&apos;s total production was 247,500,851 barrels. In 1929 Oklahoma&apos;s total production was 252,229,474 barrels. The efforts of proration and curtailment programs on flush and semi-flush districts such as Greater Seminole, Oklahoma City, Logan County and others, with the natural decline of older pools, kept 1929 below 1927, but still the total was greater than in 1928. The total United States production for 1929 is herein taken as estiiated at 1,004,266,723 bbl.† Oklahoma produced 25.1 per cent. Of

Jan 1, 1930

By N. J. Grant, K. M. Zwilsky

A series of copper-alumina dispersion strengthened alloys were prepared using three different copper and two different alumina powder sizes. Improvements in strength of up to ten times that of pure copper were found in room-temperature as well as elevated-temperature stress-rupture tests. Conductivity values remained from 70 to 90 pct that of pure copper. The best alloys were based on the finest metal powder (1 p) and contained from 7.5 to 10-0 vol pet of 0.018 or 0,033 p alumina. DISPERSION strengthening of metals consists of strengthening a metal matrix by the addition of oxides or other refractory constituents, followed by strain hardening, in order to reinforce the base material and extend its temperature range of application. Since the discovery of SAP by lrmannl and Von zeerleder2 in 1949, many investigators have reported data obtained on a variety of metal-inert oxide alloys.3-7 The present work deals with the mechanical mixing of copper and alumina powders. While several techniques of introducing the second phase have been investigated to date, mechanical mixing so far has been recognized as the simplest, least expensive, and most universally applicable technique that can be used to obtain an ultrafine dispersion of inert particles. In the present case, the effects of changing the metal particle size, the oxide particle size and the volume percent of oxide were investigated. This work is an extension of a previous study.6 EXPERIMENTAL PROCEDURE The starting materials were three different grades of copper powder and two different alumina powders. The three metallic powders were -74 µ(- 200 mesh) electrolytic copper powder consisting of irregular equiaxed particles having a normal screen distribution and analyzing 99.5 pct Cu, and two powders having a 5-µ and 1-µ particle size, average, respectively. The latter powders were produced by the hydrogen reduction of purified sulfate solutions at elevated temperature and pressure and were furnished by the Sherritt Gordon Mines, Ltd. The alumina used was obtained from Godfrey L. Cabot Co., under the trade name of Alon C, one batch of powder having a particle size of 0.018 µ, the other a particle size of 0.033 µ. The crystal structure of these alumina powders was found to be cubic gamma. Each batch of powder was mixed in a Waring Blendor for a total of 15 min, followed by a low-temperature reduction in hydrogen and vacuum compacting in cylinders which were hydrostatically pressed at 35,000 psi to give a compact that could be handled conveniently. Six of the compacts were hydrogen sintered at 900°C while the remaining four were sintered at 1000°C. Subsequently, all compacts were hot extruded at 760°C with a reduction of area ratio of approximately 20 to 1. Evaluation of alloys included density and resistivity measurements, room-temperature tensile tests, stress-rupture tests at 450°C plus one other temperature per alloy, hardness tests, microstruc-tural examination, X-ray analysis of the dispersed phase after dissolving the metal phase, and oxidation studies on two of the alloys. A vacuum-melted, wrought copper rod was tested together with these alloys for comparison purposes. RESULTS Table I is a summary of the compositions, sintering temperatures, densities and conductivity values of the ten alloys prepared. All alumina additions are given in volume percent, and will be referred to as

Jan 1, 1962

By John W. Cabot

The following series of analyses, which may, be of interest to Bessemer-steel makers, is submitted as a contribution to the muchvexed discussion of manganese in Bessemer steel. They were made by the writer in the spring of 1881, at the works of the Pittsburgh Bessemer Steel Company Limited, during a&apos; period of about eight days, part of. which time the rail-steel showed great variation in rolling qualities. During the first part of tile time in question, it rolled well; later on it began to roll wome until, finally, it cracked very badly, reaching its worst stage. After this it rapidly improved until it again rolled smoothly. During this time of transition from good rolling to bad, and hack to good again, the course of the manganese was followed quite closely. It is the striking correspondence between these varying manganese contents and the differences in rolling which is here presented as worthy of notice. The other ordinary elements were determined occasionally, but showed no. unusual variation: The steel, in question, was ordinary rail-steel of about the following compusition : C=35. P - .08. Mn - .98. Si = .08. 8 = .06. The samples for manganese determinations were taken at first from an average of two days&apos; work, and later on, when the steel

Jan 1, 1882

By Juptner von Jonstorff

A discussion of the paper by Messrs. Jüptner von Jonstorff, Blair, Dillner and Stead, read by title at the Lake Superior meeting, but presented first at the New York meeting of the Iron and Steel Institute (October, 1904), and here published under a mutual agreement between the two Institutes. Correspondence. MR. R. HAMILTON (Glengarnock) wrote to say that it was known for many years, that unless certain precautions were taken in dissolving the sample, there was a liability to obtain a solution from which the ammonium-molybdate solution would not precipitate the whole of the phosphorus. In 1877 Blair and Finkiner independently attributed this interference to the presence of carbonaceous matter in the solution, derived from the action of acids on the combined carbon of the metal, and they directed that the solution should be prepared in such a manner as to destroy these carbonaceous compounds. This was practically effected by evaporating the acid solution to dryness and roasting the residue. Adolf Tamm, in 1884, accentuated the same view. There are methods founded on the above-mentioned observations which leave nothing to be desired in point of accuracy, but the evaporation to dryness with subsequent roasting and re-solution consumes much time, besides the minor inconvenience caused by large amounts of acid fumes. In 1888 P. W. Shinier suggested that the incomplete precipitation of phosphorus was due to incomplete oxidation of -.the phosphorus, and proposed to render all the phosphorus precipitable by oxidizing the solution with potassium permanganate, etc. Experiments were made to test the accuracy of this view (details will be found in the Journal of the Society of Chemical Industry, vol. x., p. 904), and the results obtained seem to-prove that it is the correct one. It was first proved that carbonaceous matter in solution did not prevent the precipitation of properly oxidized phosphorus

Mar 1, 1905

By Frank Firmstone

The material described below was made at Furnace No. 2, Longdale, Va., Oct. 28, 1907, during a sudden derangement of working, in the course of which the furnace became entirely bridged over and for some time no solid material whatever descended into the hearth. This caused the hearth to become so completely emptied that, at the tuyere-level, a pricker put in at one tuyere could be seen by looking in at the opposite one. The tap-hole was opened and the iron got out with some difficulty. It ran sluggishly, throwing many sparks, but was not too thick to run into the chill-molds. Naturally, the product was assumed to be white iron, which is almost always produced under similar circumstances; but on removal front the molds it proved to be very strong and tough, although full of blow-holes. Most of these blow-holes bad bright, unoxidized walls. The iron could be drilled by using a "special steel" drill, the drillings curling up similarly to those of steel. An analysis by P. W. Shimer of this unusual product gave: Si, 0.019; P, 0.228; S, 0,39; Mn, 0.042; C, 2.366; and graphite, 0:000 per cent. A cast of iron made just before the disturbance contained P, 0.98, and Mn, 1 per cent. The peculiar product seems to have been decarburized in the hearth and, at the same time, to have lost much phosphorus and manganese, either by the action of the blast in the empty hearth, or, more probably, by. contact with the cinder rich in iron which was formed at the time. Unfortunately, no specimen of the cinder was preserved, so its composition cannot be given. It seems very remarkable that, with the furnace in bad condition, the temperature should be high enough to keep such

Sep 1, 1908

By Y. Mishima, R. Shiromizu

THE equilibrium y phase in Cu-Be alloys forms by discontinuous precipitation, the new phase nucleating at the grain boundaries and growing into grains on both sides of the boundary. When the alloy is aged above 500°C, however, growth may take place into only one of the grains.1&apos;2 In A1-Ag alloys it is known that the precipitate has the same orientation as the grain in which no growth takes place.3, 4 This was confirmed in the present investigation on a Cu-Be alloy. A Cu-1.79 wt pct Be alloy was solution-treated at 810°C for 2+ hr, quenched into water at O°C, and aged at 600°C for 1 hr in a salt bath. The specimen was thinned by chemical polishing and electropolishing at room temperature in a solution of H3PO4 saturated with CrOs. The foil produced was examined in a JEM 150 electron microscope operating at 150 kv. Fig. 1 shows precipitates growing on only one side of the grain boundary. The black platelike precipitates were identified as the y phase. Electron dif-

Jan 1, 1969