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By Robert W. Hunt

I have frequently stated that while the chemical composition of steel is important, yet even greater importance is connected with the mechanical and heat treatment of the metal. During the past year I encountered such a positive example of that fact that I deem it worth putting upon record. A prominent railway system divided an order for open-hearth steel rails between two steel works, both of which are under the control of the same corporation; giving to one about 18,000 tons, and to the other 7,500 tons of the same section and to be made under the same specifications. The rolling results obtained in the two mills varied so widely that a study of the figures is intensely interesting and serves to illustrate the advantages obtained by carefu1 ingot casting, and, quite as pertinently, the possible benefits of careful subsequent heating and rolling with moderate reductions in the rolling process. The smaller order was rolled complete in four installments during the same months that the larger order was being made in six separate installments; but, to permit of exact comparisons, the totals of the four installments (completing the order with the mill which I will call A) are given with the totals of the first four installments of the larger order, made by the mill designated as B. These rolling results are: Mill A. Mill B. Number of rollings,............................................ 4 4 Total number of rails rolled................................ 18,278 27,832 Percentage of rails cut to short lengths because of flaws near ends, etc......................................... 0.7 7.6 Percentage of rails made second quality for flaws, etc. 0.9 6.3 Percentage of rails scrapped for flaws, etc............... 0.6 4.5 Percentage of rails scrapped for failure at drop test... none 3.4 It should be stated that the figures given above cover all the reasons for putting the rails in the classes stated, Thus a part of the percentage of rails cut to short lengths may have been

Jan 1, 1914

By Frederic Benard

This paper constitutes a preliminary report on experimental work done to date on the anode-furnace treatment of blister copper containing relatively high percentages of nickel. The investigation has not been completed but results obtained to date are considered of sufficient interest to warrant publication. Blister copper treated by the Ontario Refining Co. originates from the Copper Cliff smelter of The International Nickel Company of Canada, of which the former is a wholly-owned subsidiary. The blister as received contains from 0.50 to 1.50 per cent Ni, and in this respect differs from that treated by other refineries on this continent. During the anode-furnace treatment, only a portion of the nickel content is removed, and of the amount remaining in the anodes a varying percentage is found in the anode slimes. This necessitates a more extensive treatment than ordinary nickel-free material. Sometimes it is necessary to repeat roasting and leaching operations several times before the nickel content is low enough to permit the slimes to proceed to the dore furnace. This, besides increasing treatment charges, causes greater selenium stack losses and involves a longer tie-up of precious-metal values. Therefore this investigation was undertaken with the aim of determining the factors influencing the diversion of nickel into the anode sludge. From experience it was known that by keeping the nickel content of anodes at 0.55 to 0.60 per cent maximum a relatively satisfactory slime resulted. One avenue of attack therefork was developing improved elimination in the anode-furnace treatment so that the anode content mentioned above was not exceeded. Another angle was to improve the solubility, during electrolysis, of the nickel constituent in the anodes, thus decreasing the percentage diverted to slimes. It may be mentioned here that nickel dissolving electrochemically and entering the electolyte presents no difficulty from a treatment standpoint. Both of these approaches were studied and are discussed separately below.

Jan 1, 1944

Discussion of the paper of Ernest Stütz, presented at the New York Meeting, October, 1913, and printed in Bulletin No. 79, July, 1913, pp. 1257 to 1265. H. 0. HOFMAN, Boston, Mass.:-I have hunted in vain for a figure which gives a dehydration temperature of cement. I was wondering if Mr. Stütz had a figure of that kind. E. STÜTZ :-No, I am afraid I have not. H. 0. HOFMAN :-I believe some figures have been published that cement disintegrates at 400° or 500° C. It seems tome a very low temperature. Mr. Stütz just made the statement that the disintegration of this briquette begins at the temperature at which the briquette begins to sinter. E. STÜTZ :-Above the sintering point. H. 0. HOFMAN :-The sintering point would be about 1,200° C. E. STÜTZ :-Yes, roughly speaking. I am afraid I have no information about the exact degree of dehydration. H. O. HOFMAN :-I have looked a great deal for such a figure and I have not been able to obtain it. Professor Howe says I might have tried myself. But my interests were directed in another line; although-that is, perhaps, a good suggestion. CHAIRMAN RICHARDS:-Is not Portland cement sometimes used for the test in a cupellation furnace and a drying-out furnace ? H. O. HOFMAN :-Yes, it is used, but that is a higher temperature, of course. But I have been trying to get a figure as to where it loses all its water. I understand it begins to lose water at 500° C. But there are different silicates or hydrosilicates in the cement, so that one would have four or five or sit figures to show the different stages at which the cement loses its water. CHAIRMAN RICHARDS :-I would ask whether the use of this material in blast furnaces has shown increased capacity of furnace or decreased consumption of fuel.

Jan 12, 1913

By M. E. Nicholson

The solubility of carbon in Ni-Cu alloys was determined at 1000°C. The factors which limit solid solubility are discussed with particular reference to the influence of electronic factors. The results indicate the extent of solid solubility is a function of the density of states at the Fermi surface. THE solid solubility of an interstitial element is primarily limited according to Seybolt and Fullman1 and Speiser and Spretnak2 by (a) the strain energy produced when the solute atom takes its interstitial position, and (b) the partial molal free energies of the solid solution and the coexisting phases. In several binary systems of a transition and a noble metal, where there are no abrupt changes in strain energy or free energies of coexisting phases, the solid solubility of an interstitial third element drops abruptly to a negligible value at a composition corresponding to a complete filling of the "d-band." Such a decrease occurs in the case of hydrogen in the Pd-Ag system at 60 pct Ag.3,4 The solubility of carbon in Ni-Cu alloys seems to vary in a similar manner as indicated by the embrittling effect of carbon on these alloys. These al- loys are embrittled by slow cooling due to the precipitation of graphite. This embrittlement can be removed by heat treatment if the carbon content is less than the solid solubility limit at the heat-treating temperature. If the carbon content of the alloy exceeds the solid solubility at the heat-treating given temperxture, the embrittlement cannot be eliminated by solution heat treatment.' Since pure nickel has a carbon solubility of 0.25 wt pct6 at 1000°C, embrittlement is easily removed from commercial nickel and nickel-rich alloys, which may contain of the order of 0.10 wt pct C. Embrittlement due to carbon cannot be removed from Ni-Cu alloys containing 70 to 80 wt pct Cu by annealing unless: the carbon content is of the order of 0.04 wt pct CL or less."' Thus, it appears that the

Jan 1, 1962

By K. L. Meissner

IT is well known that the so-called pure aluminum contains noticeable amounts of impurities, chiefly iron and silicon, and many investigators have studied the forms in which these impurities exist. Hanson and Archbutt1 state that iron exists in aluminum as FeAl3 and silicon as elementary Si. The solubility of FeAl3 in solid aluminum is practically zero, or at, least so small that the smallest trace of this compound is always visible as a separate constituent. Under the microscope an untrained eye can hardly distinguish, without etching, the two constituents FeAl3 and Si, but they can be differentiated by suitable etching reagents. Anderson2 also found the same results. At the same time, Merica, Waltenberg, and Freeman3 found a constituent of unknown composition. They found a small thermal effect, at 610° C., on the cooling curves of aluminum with small amounts of iron and silicon. The intensity of this effect increased with increasing silicon content, until an effect occured at 576° C. due to the eutectic between aluminum and silicon. The authors ascribed the effect at 610° C. to a compound, which they call "X constituent." It was thought to be a ternary compound containing iron and silicon and could be observed under the microscope as dark particles. Dix4 has published unetched photomicrographs of an aluminum with 0.51 per cent. iron, 0.99 per cent. silicon, and 0.32 per cent. copper that shows three constituents: the dark Si (black in the figure), the lighter FeAl3, which appears in half tone and crystallizes in needles, and a constituent of the same color as FeAl3 but of different crystal form, often resembling Chinese script. This last constituent, Dix thought, is a compound of Fe and Si; not the compound FeSi but a compound containing a relatively small amount of silicon. Therefore an alloy of aluminum, iron, and silicon (the copper should not be regarded in the following considerations) must contain the following four constituents: Al, FeAl3,

Jan 1, 1926

By J. L. Weeks

THERMAL conductivities of several samples of uranium and uranium alloys were determined using an apparatus previously described.' The value previously reported for uranium,' 0.035 cal per sec per cm per "C at 70°C, is in error due to the failure of a thermocouple during the determination on uranium. The defective thermocouple was detected after a reanalysis of the data obtained during the run and since has been replaced. Subsequently, runs on several samples of uranium show the thermal conductivity of uranium to be 0.069 cal per sec per cm per 'C at 70°C. The accuracy of the determinations was checked by measuring a sample of synthetic sapphire whose thermal conductivity was previously reported and found to be in agreement with other values."-" The values given in Table I are believed correct to % 3 pct or 0.003 cal per sec per cm per "C, whichever is larger. The samples were provided by J. H. Kittel of the Argonne National Laboratory, Metallurgy Div. References J. L. Weeks and R. L. Seifert: Apparatus for the Measurement of the Thermal Conductivity of Solids. Review of Scientific Instruments (1953) 24, pp. 1054-1057. J. L. Weeks and R. L. Seifert: Note Regarding the Thermal Conductivity of Synthetic Sapphire. Journal American Ceramic Society (1952) 35, p. 15. :' J. Francl and W. D. Kingery: Thermal Conductivity: IV, Apparatus for Determining Thermal Conductivity by a Comparative Method; Data for Pb, Al2O3, BeO, and MgO. Journal American Ceramic Society (1954) 37, No. 2, Part 11, pp. 80-84. (Part 11: special issue on thermal conductivity.) ' W. D. Kingery, J. Francl, R. L. Coble. and T. Vasilos: Thermal Conductivity: X, Data for Several Pure Oxide Materials Corrected to Zero Porosity. Journal American Ceramic Society (1954) 37, No. 2, Part II, pp. 107-110. (Part 11: special issue on thermal conductivity.) Edwin Ruh: New Jersey Ceramic Research Station, Rutgers University. Private communication.

Jan 1, 1956

By C. B. Post, G. V. Luerssen

J. STEVENS*—The authors state that the contamination in the metal was due mostly to the ladle refractories. Did the contamination vary with different brands of refractories or different qualities in the ladle ? C. B. POST (authors' reply)—That would be expected. In our shop we have used a grade of firebrick which is fairly standard. We do use high refractory nozzles to combat this erosion and high refractory sleeves, but there is such a problem when you get a skull in a ladle you just cannot use these high refractory bricks; you rip out the whole ladle getting the skull cleaned up. The acid bricks form a glass, and you can pull the skull out when you do get them. I believe you might find variations among the different refractories depending on how much silicon is in the brick. This determines how much silica is going into the interface between the steel and the brick. Our brick is about 35 pet alumina and 65 pet silica. With a brick of 35 pet alumina in the slag patches new calculations would have to be made. R. PARDEE*—Where can you draw the line in determining the refractories as being a silica refractory ? C. B. POST—More silica than about 50 pet. I think perhaps that is generally the criterion. The brick we use is a good high grade fire brick. T. S. WASHBURN*--With reference to the higher silicon that is recommended as a result of this investigation, is it contemplated that the specified range would be raised to 0.40-0.60 pet silicon, or possibly 0.50-1.00 pet silicon? These higher silicon ranges would affect the physical properties of the steel and consequently there might be some complications with respect to educating the consumers to 'accept this revision of the conventional analysis. C. B. POST—It will take considerable work. Take AMS 6260 as an example. Ordinarily this specification calls for 60 or 75 manganese. Silicon has some

Jan 1, 1950

By J. P. Hammond, C. J. Sparks, C. J. McHargue

IN a study of the effects of solid solution alloying on the deformation texture of titanium, an alloy containing 3.8 pct A1 was found to develop a (0001) [1010] texture instead of the texture characteristic of pure titanium.ls2 A short investigation has been made of the change in texture with aluminum content. Alloys containing 0.27, 0.47, 1.05, and 1.43 pct A1 were prepared by vacuum arc melting, using iodide titanium as the base material. Homogenized ingots were reduced 90 pct in thickness by cold rolling. Pole figures were obtained using the usual film techniques. Fig. 1 shows that the change from the tilted to the nontilted (0001) position is gradual. The dashed contour lines in Fig. 1 indicate the extent to which data was collected. The addition of 0.27 pct A1 resulted in a decrease in the transverse spread of basal poles. With increasing aluminum content, the amount of the tilt becomes less and the region of highest intensity takes the shape of a ring about the center of the pole figure. For aluminum contents greater than 1 pct, the (0001) [1010] texture is definitely present—the sharpness increasing as the amount of solute is increased.* It is interesting to note that Williams and Eppel-sheimer9 eported for commercial grade titanium a high intensity region 20" toward the rolling direction from the rolling plane normal in addition to. one 30" toward the transverse direction. Their basal pole figure was similar to Fig. 1, row inree. The observation that the texture changes gradually with solute concentration is similar to the results of similar studies on copper." At the present time these effects are not clearly understood. Acknowledgments This work was sponsored by the Aeronautical Research Laboratory (WCRRL), Wright Air Development Center, under Contract NO. AF' 33(038)-19574. The authors are grateful for the aid received and permission to publish these results.

Jan 1, 1958

By C. D. Woodward

PRIOR to 1902, the tramming of ore from the stopes to the shafts, in the Butte mines, was done by man or animal power, but the demand for greater tonnage and the need for more improved methods of tramming the ore resulted in the installation of the compressed-air locomotive in a few mines. Some of the objections to animal haulage were thus eliminated, but this locomotive was not generally adopted, because of a number of limiting features. It was superseded by the electric trolley locomotive. The early types of trolley locomotives were not satisfactory from the operators' viewpoint, but. they had many economic advantages and after a number of years, in which improvements were constantly made in the structural details, they became dependable, so that the use of animals for main haulage in the mines has now been practically abandoned. There are now operating in the Butte mines of the Anaconda Copper Mining Co., 185 trolley-type locomotives, each of which has replaced five animals. It cost approximately $50 per month to keep an animal, hence the economies that resulted fully justified the expenditure of electrifying the haulage systems. The haulage conditions in this company's mines possess many advantageous features that are not always found in underground mine workings. The drifts and crosscuts are large, approximately 5 ft. (1.5 m.) wide by 7 ½ ft. (2.3 m.) high, and have curves of no less than 18 ft. (5.5 m.) radius; and the roadbeds of the drifts and crosscuts have a uniform grade of 0.5 per cent. toward the shaft, or in favor of the loaded trips. In all of the mines, except two, the track gage is 18 in. (45.7 cm.), and all tracks in the main haulageways are laid with 25-lb. (11.3 kg.) rails. The stations at the shaft are large, well-lighted, clean, and cool. The average temperature of ,the stations, however, is about 75° F. (24° C.), while the average temperature in some of the drifts and crosscuts is 92° F. (33.5° C.).

Jan 2, 1922

By R. W. Heckel, R. L. DeGregorio

The DeHoff method of determining the size distribution of ellipsoid-shaped, second-phase particles has been applied to the spheroidization of cementite in a eutectoid steel. The surface area of Precipitates determined from the various size fractions in the distribution was correlated with surface-area measurements based on the number of intersected interfaces on a random lest line. The precipitate particles were found to be oblate ellipsoids with an axial ratio of about 0.90. The size distributions were found to be log-normal. A method is proposed whereby the shrinkage of small particles and growth of large ones can be determined from the experimental data. The experimental data are compared to previously proposed mathematical models describing diffusion-controlled kinetics and various types of interface-controlled kinetics. The experimental growth and shrinkage rates are considerably slower than those predicted by diffusion-controlled kinetics. The best fit is obtained for a model describing interface-controlled kinetics limited by the rate of formation of cementite at the growing interfaces where the interfacial reaction rate is proportional to the solute thermodynamic activity gradient across the surface. THE subject of spheroidization of second-phase particles has been considered previously by other investigators. Livingston1 has studied the precipitation of the cobalt-rich phase from copper alloys containing 0.7 to 3.2 wt pet Co. His results indicate that the average particle size increases as the cube root of the heat treatment time in accord with diffusion-controlled kinetics.'-' Komatsu and rant' in their studies of the growth of SiO2 in a dispersion-strengthened copper-silica alloy found that the initial growth of SiO2 proceeded by diffusion-controlled growth and later stages were limited by interface-controlled growth. The values of the activation energy obtained for the interface- controlled process led them to the conclusion that the process was limited by the dissociation of SiO2 at the shrinking interface. The transition from diffusion-controlled growth to interface-controlled growth was characterized by a particle size which varied with the heat-treatment temperature. It is also interesting to note that the particle-size distribution as found by Komatsu and Grant exhibits log-normal behavior when replotted on log-probability coordinates. Dromsky, Lenel, and Ansell9 have observed the growth of Al2O3 particles having a mean free path of about 1.5 to 13 µ. Their photomicrographs indicate that the Al2O3 particle sizes were larger than those observed by Komatsu and Grant. Dromsky, Lenel, and Ansell concluded that the Al2O3 coarsened by an interface-controlled growth mechanism limited by the solution of A12O3 at the shrinking interfaces. Bannyh, Modin, and Modin10 have studied the spheroidization of a eutectoid steel (0.83 wt pet C). Their spheroidization (tempering) treatments were carried out in the range from 210o to 700°C for times between 1.5 sec and 20 hr. Measurements of mean particle size as a function of time indicated a cube root of time dependence of size at 700°C, in agreement with previous analyses of diffusion-controlled kinetics.2°7 At lower temperatures, the time dependence was less than the one-third power. It is important to note that, although mathematical models of growth* considering particle-size distribution have been available, measurements of only mean particle size have been carried out. DeHoff11 has presented a quantitative metallography technique which is applicable to the determination of the size distribution of ellipsoids of constant shape. This method is applicable to both oblate and prolate ellipsoids of all ratios of minor to major axis and is based upon an extension of Saltykov's analysis12 of the distribution of spheres of varying size. DeHoff's analysis is based upon measurements of the minor axis of the particles on a random plane of polish in a unit area. This method provides a measure of the number of ellipsoids in various size ranges per unit area. As pointed out by DeHoff, such measurements may be used to obtain surface area and total precipitate volume data. Thus, the accuracy of the distribution analysis may be checked by comparison of the surface and volume

Jan 1, 1965

By M. Cohen, R. J. Teitel

There is considerable interest in beryllium because of its low density (1.84 g per cu cm), high modulus of elasticity (40 X 106 psi), high melting point (1280°C), and special nuclear characteristics. Moreover, it has fair resistance to corrosion and oxidation. However, the purest beryllium known to the authors is relatively brittle at room temperature, and cannot be fabricated readily. The search for improved properties leads naturally to investigations of beryllium alloys and the phase relationships upon which they are based. The present paper is concerned with the alloys of beryllium and iron, primarily from the standpoint of the equilibrium diagram. Iron was selected (1) because of its all-round importance in metallurgy, and (2) because the beryllium-iron system is known to be quite complex. The most recent diagram in the literature is that of Gaev and Sokolov,' and covers only the iron-rich end up to 16 wt pct beryllium. Beryllium markedly restricts the austenitic field, closing the gamma loop at about 0.4 wt pct (3 at. pct). On the other hand, beryllium is soluble in a-ferrite up to a maximum of 7.5 wt pct (34 at. pct) at the eutectic temperature of 1160"C. The eutectic composition lies at 10 wt pct beryllium (42 at. pct) and corresponds to a mixture of or and FeBez (called j3 in the present paper). The solid solubility of beryllium in the a phase decreases with decreasing temperature, and makes precipitation-hardening possible. These findings substantiate the earlier work of Oester-held,2 Wever and Mueller3 and Laissus.4 In addition to the FeBe2 (ß) mentioned above, Misch6 has reported on FeBes, and indicated evidence for another compound containing still more beryllium. A preliminary diagram by Gordon,5 not hitherto published, is given in Fig 1. Besides the phases previously named, there are shown a solid solution of extended range (e), a compound of limited solubility (t), and a high temperature phase (7). Beryllium is designated as 8. The t field contains the compound composition FeBea, and the f phase undoubtedly corresponds to the beryllium-rich compound found by Misch.6 The region around the { phase was proposed by R. J. Teitel based on Gordon's data. The details of the diagram are self-explanatory. It was the unusual complexity of this system that prompted the authors to undertake the present studies. By the same token, more emphasis was placed on the beryllium-rich than the iron-rich end of the diagram. Exprimental Details RAW MATERIALS The beryllium employed in this investigation was one of the purest grades available. Its chemical analysis after vacuum melting is given in Table 1. The metal assayed 99.4 wt pct beryllium. Vacuum melted electrolytic iron of purity shown in Table 1 was the source of iron.

Jan 1, 1950

By C. Atkinson

A method is described for the numerical solution of the diffusion equation with a composition-dependent diffusion coefficient and applied to the radial growth of a cylinder; the radial growth of a sphere, and the symmetric growth of an ellipsoid. Sample applications of the method are made to the growth of particles of proeutectoid ferrite into austenite. RECENTLY&apos; we described a method for numerical solution of the diffusion equation with a composition-dependent diffusion coefficient for the case of the growth of a planar interface. In this paper we extend this method to describe the radial growth of a cylinder, the radial growth of a sphere, and the symmetric growth of an ellipsoid. In the latter case, limiting values of the axial ratios of the ellipsoid reduces the problem to one of a cylinder, a sphere, or a plane depending on the axial ratio. A check on these limiting values is made in the results section. In all of these cases we consider growth from zero size. A natural consequence of this assumption as applied to the sphere, for example, is that the radius of the sphere is proportional to the square root of the time. This is consistent with the condition that the radius is zero initially, i.e., grows from zero size. It may be argued that it is more realistic to consider particles which grow from a nucleus of finite initial size; even in this case the analysis of this paper is likely to be applicable. This can be seen if a comparison is made of the work of Cable and Evans,2 who consider a sphere of initially finite size growing by diffusion in a matrix with a constant diffusion coefficient, with the results of Scriven3 for growth from zero size. This comparison shows that the rates of growth in each case differ trivially by the time the particle has grown to about five times its initial size." This investigation is a generalization of those of Zener,4 Ham,5 and Horvay and cahn6 to the situation often encountered experimentally, in which the diffusion coefficient varies with concentration. First let us consider each of the cases separately. I) GROWTH OF SPHERICAL PARTICLES FROM ZERO SIZE In this case the differential equation in the matrix depends only on R, the radius in spherical coordinates, and can be written: ? 1 <^\ ^13D . , dt U\dRz + R 3Rj + dR dR [ J where C is the composition, t is the time, and D is the diffusion coefficient which depends on c. The boundary conditions will be: c = c, at the moving interface in the matrix, c = c, at infinity in the matrix (and at t = 0, everywhere in the matrix), c = X, is the composition in the spherical particle. Each of the above compositions is assumed constant. In addition there is the flu condition at the moving interface which can be written: , dR0 ~/3c dt \dR/H =Ra where R,, which is a function of t, is the position of the moving interface. We make the substitution q = RI~ in [I] reducing this equation to: & - m - *ws) »i where we have written D = D,F(c) or simply D,F, and Do = D(c,). Thus F[c(q0)] = 1 where q, = ~,/a is the value of the dimensionless parameter q evaluated at the interface. Multiplying Eq. [2] by dq/dc and integrating, we find: where the lower limit of the integral has been chosen so that dc/dq — 0 as c — c,, thereby satisfying the boundary condition at infinity. We require, then, to solve Eq. [3] subject to the condition c = c, when q = q, (this follows from putting R = R, at the interface) together with the flux condition which can be rewritten in terms of q as: Eqs. [3] and [4] together with the condition c = c, at q = q0 enable us to find 77, and the concentration profile c = c(q). Numerical Method. We treat Eq. [3] in the same way as we did the corresponding equation for the planar interface problem&apos; i.e., by dividing the interval c, to c, into n equal steps so that: cr = ca -rbc [5] where r takes the values 0, 1, ... n and we call no,, q1, ... nn the values of n corresponding to the compositions c,, c,, ... c,.

Jan 1, 1970

By H. Rosenthal, A. L. Jamieson

Stress-corrosion cracking of copper-base alloys is of considerable importance and has been the subject of many investigations which employed various accelerated tests and long-time service tests. The outstand¬ing accelerated tests used are variations of either the mercury cracking test reported by Rogers in 1905( 1)2 or the ammonia test reported in 1910(2). The ease of applica¬tion of the mercury test is probably the reason industry adopted it. Subsequent investigation of this test(3,4) revealed that a minimum threshold stress was necessary before mercury cracking could develop. Since season cracking has been found in some instances in caliber 0.3o ammunition which has passed the mercury test, it is evident that the threshold stress value of the mercury test may be too high for dis¬tinguishing between acceptable and un¬acceptable caliber 0.30 cartridge cases. This condition has naturally led to the study of an ammonia test with its ability to cause cracks with almost any stress level. But the lack of a definite threshold value means that standards are necessary for evaluating the results of the ammonia test.

Jan 1, 1945

By E. W. Johnson, M. L. Hill

The dijfusiuity D was determined at 25° to 780°C- from hyd?-ogen evolution rates. Anomalous evolution from air-melted iron was att~zbztted to residual hydrogen, which is interpreted as a hydrogen compound that decomposes at a strongly temperature-(Ieperzdent rate above 500°C. Above 200°C, D = 0.0014 cm2sec-1 exp (-3200 cal per g atom/RT). Below, 200°C the diffusivity is anomalously low and represented by D = 0.12 cm2sec-l exp (-7820 cal per g atom/RT). It is postulated that at low temperatures the hydrogen in the metal is "trapped" with an energy 4.8 kcaL per g atom below- that of the interstitial hydrogen. 1 HE purpose of the present experimental study was to determine the diffusivity of hydrogen in a-Fe over an extended temperature range. As certain anomalies were encountered, attempts were made to understand the anomalies themselves. This research was in progress both before and after a determination of the diffusivity of hydrogen in nicke1.l The latter system was found to exhibit none of the anomalies of hydrogen in iron, and its description was far simpler. The experiments on nickel also

Jan 1, 1961

By R. H. Richards, C. E. Locke

In "Sorting Before Sizing " (a paper first announced at the Pittsburgh meeting, February, 1896, but delayed in preparation and now presented at the present meeting) it is shown that if slime-tables are to do their best work on slimes below 0.5 mm. or 0.05 inch in diameter, they must be carefully sorted or classified, and fed to a series of tables suitably adjusted to the different slime-sorts. The reason is that the coarser and finer slime-sorts require respectively different adjustments of the tables. Hence, if the two are fed together upon a table which has, as nearly as may be, average adjustments, fine galena, for example, will go into the tails, or coarse quartz into the heads, or both—losses which could have been largely prevented if the slime had been carefully sorted and each sort sent to its own slime-tables. As indicated in the paper just mentioned, the present tendency in this country is generally to do away with slime-sorting or "classification," and simply to take the overflow from the hydraulic classifier and divide it among the tables by means of

Jan 1, 1898

By Robert W. Hunt

Delays in the completion of the alterations to the plant at the works of Messrs. Oliver Bros. and Phillips, in Pittsburgh, coupled with the increased demand for metal made from regular Bessemer pig, placing the firm many hundreds of tons behind in their deliveries, prevented Mr. Henry W. Oliver, Jr., from redeeming his promise to place his works at my disposal for further tests of high-phosphorus irons, until May 5th. Upon that date, I assumed charge of the operations in his steel-plant. Mr. Oliver had purchased Neshannock pig as a basis for a supply of phosphorus. My information is to the effect that this iron is made from low-grade Lake Superior ores and mill-cinder, the latter "ore" being utilized to about 40 per cent. of the total mixture. At all events the pig had quite as much phosphorus, and in as varying quantities, as the most exacting could desire. My experiments of last fall had well satisfied me as to the effect of from 0.35 to 0.55 per cent. of phosphorus in the Clapp Griffiths metal. Hence at this time my first trials were directed to

Jan 1, 1886

By K. S. Seljesater

Since the development of dispersion-hardenable lead-antimony alloys&apos; in the laboratories of the Western Electric Co., Inc., studies have been made of the effect of various third constituents on these alloys.2 This paper covers a study of the effect of small amounts of arsenic. This element is important since it occurs as an impurity in many commercial antimonial leads and the results obtained are particularly interesting as indicating a class of addition agents which exert a stabilizing effect on dispersion-hardened alloys. Experimental In order to study the effect of increasing amounts of arsenic, a series of alloys were made up containing 1 per cent. antimony, and arsenic varying from 0. to 0.10 per cent., the balance Doe Run lead (99.997 per cent. lead). The alloys were cast into bars 1 1/2 in. wide by 3/4 in. thick and cold-rolled to about 1/8 in- thickness. Three samples of each composition were annealed 1 hr. at 225" C. and quenched in water. One set was aged at room temperature, one at 50" C., and the third at 100" C., the

Jan 1, 1929

By K. S. Seljesater

Since the development of dispersion-hardenable lead-antimony alloys&apos; in the laboratories of the Western Electric Co., Inc., studies have been made of the effect of various third constituents on these alloys.2 This paper covers a study of the effect of small amounts of arsenic. This element is important since it occurs as an impurity in many commercial antimonial leads and the results obtained are particularly interesting as indicating a class of addition agents which exert a stabilizing effect on dispersion-hardened alloys. Experimental In order to study the effect of increasing amounts of arsenic, a series of alloys were made up containing 1 per cent. antimony, and arsenic varying from 0. to 0.10 per cent., the balance Doe Run lead (99.997 per cent. lead). The alloys were cast into bars 1 1/2 in. wide by 3/4 in. thick and cold-rolled to about 1/8 in- thickness. Three samples of each composition were annealed 1 hr. at 225" C. and quenched in water. One set was aged at room temperature, one at 50" C., and the third at 100" C., the

Jan 1, 1929

By W. M. Morris

THE volumetric behavior of isobutane at temperatures below its critical temperature has been studied by several investigators. Seibert and Burrell1 measured the vapor pressure of isobutane from the ice point to the critical temperature. Dana and co-workers2 determined among other thermodynamic quantities the density of the saturated liquid and the saturated gas and the vapor pressure from approximately 0° to 130° F. Sage and Lacey3 studied a number of the thermodynamic properties of this hydrocarbon from 70° to 250° F. The specific volume in the gas and liquid region was determined at pressures up to 3000 lb. per sq. in. ? throughout this temperature interval. In addition, the vapor pressures were measured at 30° intervals. These data taken together serve to establish the thermodynamic behavior of isobutane at temperatures between 0° and 250° F. with reasonable accuracy. However, apparently there are no data available at the higher temperatures. For this reason an investigation of the volumetric behavior of isobutane at temperatures between 100° and 460° F. was carried out with apparatus that has been described in another paper (A.I.M.E. Tech. Pub. 1127).

Jan 1, 1939

By D. W. Frommer

Processing nonmagnetic taconites by selective flocculation-desliming and flotation requires large volumes of water. If impounded without treatment the effluents from these processes require excessively large areas for containment. Experiments conducted in the Bureau of Mines 900-lb-per hr pilot plant at the Twin Cities Metallurgy Research Center indicates that approximately 85% of the water needed to process Michigan nonmagnetic taconite could be reclaimed from the process itself. Water was reclaimed by the controlled addition of lime, sodium carbonate, and synthetic flocculant. As a result, turbidities were reduced to ?1000 ppm equivalent SiO2, while a Ca ion content of ?16 ppm was maintained in the finished effluent. Good-quality flotation concentrates were obtained with reclaimed water and, by means of some indirect comparisons, it can be concluded that the reuse of the water permits a savings of almost 2.0 lb per ton of NaOH, and probably as much as 0.25 lb per ton of fatty acid for total savings of 7.8-10.3 cents per ton of feed. These savings are nearly offset by an estimated chemical cost of 9.3[c] per ton for water treatment.

Jan 1, 1970