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The following delegates were appointed to the National Conservation Congress on May 2, 3, and 4, 1916, in Washington, D. C. HENRY S.. DRINKER, a GEORGE OTIS SMITH, A. F. Lucas, - W. L. SAUNDERS, VAN H. MANNING. President Ricketts was appointed delegate to the dedication ceremonies of the new buildings of the Massachusetts Institute of Technology in June. W. L. Saunders was appointed delegate to the ceremonies in celebration of the 150th Anniversary of the founding of Rutgers College to be held in October. George C. Stone was appointed delegate to the meeting on Standard Screen Scale of the U. S. Bureau of Standards. George D. Barron and Thomas T. Read were appointed delegates to the Second National Exposition of Chemical Industries to be held in New York in September. It was resolved, that the Institute shall pay the transportation of the Secretaries of the Local Sections to and from the Arizona Meeting. It was resolved that certain general topics' should be selected for discussion at the next meeting of the Institute and a session devoted to each.

Jan 6, 1916

By J. W. Hickman

INTRODUCTION RECENT work by the authors1 on the oxide films formed on alloys of titanium and zirconium with nickel and copper indicated that an investigation of the oxides which form on alloys of copper and nickel might permit the relative rates of formation and diffusion of the ions of. these metals to be determined. This binary system is of further interest since the alloys which form are of the solid solution-type over-the entire range. In addition nickel is much more oxidation resistant than copper. A comparison of the free energies of formation of the simple oxides which may occur on these alloys indicates that nickel oxide should be observed over the entire time and temperature ranges of oxidation for all alloy compositions.1 In. order for nickel oxide to predominate on the surface, it is necessary that nickel ions form and diffuse to the surface. Two factors which may influence the formation of nickel oxide may be the ionic sizes, where Cu+ is 0.96Å and Ni-++ is 0.70Å, and the charges on the ions. On the basis of size, Ni++ should diffuse more readily than Cu+ while on the basis of charge, Cu+ should form more readily than Ni++. According to Uhlig2 passivity to corrosion in an alloy appears at a critical composition which for copper-nickel alloys is related to the tendency of the d band of electronic energy states to fill with electrons. This composition in the copper-nickel alloys corresponds to 40 at. Pct nickel at which composition Uhlig2 (quoting La Que's data) states that the alloy system becomes passive. Magnetic and specific heat data indicate that the d band of copper-nickel alloys is filled at 6o at. pct copper or 4o at. pct nickel. Mott and Jones3 have shown that if, on alloying nickel with copper, one considers a copper atom to be identical with a nickel atom except for an extra electron (nickel -has the-configuration: 3d8 4s2 and copper: 3 d10 4s) then at 60 at. pct copper or 4o at. pct nickel enough electrons are contributed by copper to fill the d band of the alloy. At this composition the magnetic susceptibility approximates zero according to Grew.4 Although the electron diffraction data will not determine the rates of the several reactions which may occur during oxidation, yet a determination of the structures of the surface oxides may yield information concerning the relationships, if any, which may' exist between the oxide structures which form and that composition where the magnetic susceptibility approximates zero. It is quite possible, of course, that the mechanisms of the oxidation and corrosion reactions may be so widely different that no correlations between them may be possible. SURVEY OF LITERATURE The metals, copper and nickel, which are face-centered cubic, form solid solution alloys which are face-centered cubic with no superstructure for all compositions. Three oxides of nickel have been investigated structurally by X ray diffraction. Of

Jan 1, 1948

By Charles F. Hickey, Eric B. Kula

Thermomechanical treatments applied to the maraging steels include a) cold working in the austenitic condition at 650°F, followed by transformation to martensite and aging, b) cold working in the murtensitic condition and aging, and c) cold working in the aged condition with and without subsequent reaging. The strength increases in these steels are very small compared to the increases observed in conventional carbon and alloy steels. The changes that are observed are compatible with the strengthening mechanisms operative during thermomechanical treatment of conventional steels, however. Differences are caused by the absence of a carbide precipitate and the low work-hardening rate in both the solution-treated and the aged conditions. ThE 18 pct Ni maraging steels represent a class of steels which are finding great interest for high-strength applications.1~2 They are essentially carbon-free, and contain 7 to 9 pct Co, 3 to 5 pct Mo, and 0.2 to 0.8 pct Ti. Although austenitic at elevated temperatures, they can be air-cooled to room temperature to form a martensite, which because of the absence of carbon is relatively soft. On subsequent reheating age hardening occurs and strength levels of 250 to 300 ksi yield strength can be attained. These steels appear to be particularly suitable for studying the response to various thermome-chanical treatments for additional reasons other than the obvious one of attempting to improve their already attractive properties. Thermomechanical treatments can be defined as treatments whereby plastic deformation, generally below the recrystal-lization temperature, is introduced into the heat-treatment cycle of a steel in order to improve the properties. With an absence of intermediate transformation products on air cooling the maraging steels have good hardenability and hence can readily be cold-worked in the austenitic condition prior to transformation to martensite. Further, they can be worked in the martensitic condition prior to aging, and even can be deformed in the fully aged condition. Finally, it is of interest to compare their re- sponse to that of the more conventional alloy and carbon steels, where the role of carbides is important in the strength increase by thermomechani-cal treatments. The thermomechanical treatment of conventional steels has been the subject of a recent review.' I) MATERIALS AND PROCEDURE The steel used in this investigation was a commercially produced vacuum-melt heat, which had been rolled to 0.090 in. and mill-annealed. The composition of the alloy was as follows: 0.02 C, 0.08 Mn, 0.10 Si, 0.009 P, 0.009 S, 18.96 Ni, 7.34 Co, 5.04 Mo, 0.29 Ti, 0.05 Al, 0.004 B, 0.01 Zr, and 0.05 Ca. Unless otherwise stated the heat treatments used were the standai-d solution treatment at 1500°F for 1 hr, air cool, followed by a 900°F, 3 hr age. In this condition, the material exhibited 232 ksi yield strength and 239 ksi tensile strength. Mechanical properties were determined by Vicker's hardness measurement (20 kg) and by tensile tests on standard 1/2-in.-wide, 2-in.-gage-length sheet tensile specimens. Notch tensile tests were run using the 1-in.-wide NASA type, edge-notched specimen.4 Fracture-toughness determinations were made on 3-in.-wide, center-notched, fatigue-cracked specimens, following the recommendations of the ASTM Committee on Fracture-Toughness Testing.4 An electric-potential technique was used for measuring the crack size at the onset of rapid crack propagation5 which is necessary for calculations of Kc, the critical stress-intensity factor under plane-stress conditions. The critical stress-intensity factor under plane-strain conditions KI, was also calculated, using the stress at which the first observable crack growth occurred. 11) RESULTS A) Cold-Worked in the Austenitic Condition. The reported M, temperature for the 18 pct Ni maraging steel is about 310°F.1 Therefore, a temperature of 650°F was selected as suitable for rolling in the austenitic condition. Specimens were solution-treated at 1500°F for 1 hr, air-cooled to 650°F, and rolled varying percentages from 0 to 60 pct, at 20 pct reduction per pass. Tensile and hardness properties after aging at 900°F for 3 hr are shown in Fig. 1. The tensile strength increases from 253 to 271 ksi and the yield strength from 247 to 265 ksi as a result of a reduc-

Jan 1, 1964

By J. L. Lehman, J. D. Sudbury, J. E. Landers, W. D. Greathouse

A full scale field experiment on cathodic protection of casing answers questions concerning (1) the proper criteria for determining current requirments, (2) the amount of protection provided by different currents, and (3) the transfer of current at the base of the surface pipe. Three dry holes in the Trico pool in Rooks County, Kans., were selected for cathodic protection tests. The three holes were in an area where casing failures opposite the Dakota water sand often accur in less than a year. Examination of the electric togs showed the wells to be similar to other wells in the field where casing in four of seven producing wells has failed. The three holes were cleaned out and cased with 75 joints of new 51/2-in. 14-tb J-55. Each joint was visually inspected and marked before it as run. The casing was bull plugged and floated in the hole 50 that the inside might remain dry and free of excessive attack. Also, if a leak occurred, a pressure increase could be observed on gawge at the surface. Extensive testing was done, including potential profiles, log current-potentid curves and electrode measurements from both surface and downhole connections. Based on these data, a current of 12 amps was applied to one well and 4 amps to mother. The third well was left to corrode. During the two-year period when the casing was in the ground, [he applied current was checked weekly, and reference electrode measurements were made about every two months. Three sets of casing potential profi1e.c were run. When the three strings were pulled, each joint was examined for type of scale formed, presence of sulfate-reducing bacteria, extent of corrosion nttnck and pit depth. Since the pipe was new when run, quantitative determination of the protection provided by current was possible. This is the first concrete field evidence to help resolve the many arguments about the proper method for selecting adequate current for cathodic protection of oilwell (-using. INTRODUCTION A casing string is run when a well is drilled. This pipe is supposed to protect this valuable "hole in the ground" for the life of the well. Often the casing does not last the life of the well; it is with these casing failures that this work is concerned. The cost of repairing a casing failure varies from field to field—from as much as a $30,000 per leak average in California to $5,000 per leak in Kansas. Additional costs other than actual repairs are also important. These include formation damage, lost production, etc. Casing damage caused by internal corrosion is important in some areas. Treatment normally consists of flushing inhibitor down the annulus, but further research is being done on control measures. The test described in this paper is concerned only with external corrosion. The problem of casing failure from external attack has appeared in several areas including western Kansas, California, Montana, Wyoming, Texas, Arkansas and Mississippi. Cathodic protection is currently being used in an attempt to control external corrosion. From reports in the NACE there are thousands of wells currently under cathodic protection. The quantity of current being applied ranges from 27 amps on some deep California wells to a few tenths of an amp being supplied from magnesium anodes on wells in Texas and Kansas. Considerable field and laboratory effort1,9,5,6 was exented on the problem of cathodic prctection of casing, and it became fairly obvious that this method could be used to protect wells. Early workers showed that current applied to a well distributed itself over the length of the casing and was not concentrated on the upper few hundred feet. Basic cathodic protection theory had shown that corrosion attack could be stopped by applying sufficient current. The problem resolved itself, then, into one of trying to decide just how much current was necessary. Various criteria were utilized in installing the many existing cathodic protection installations. These methods included the following. 1. Applying sufficient current to remove the anodic slope as shown by the potential profile." 7. Applying enough current to maintain all areas of the casing at a pipe-to-soil potential of .85 v.' 3. Applying the current indicated by a log current-potential (or E log I) curve." 4. Supplying the current necessary to shift the pipe to-soil potential .3 v." 5. Applying 2 or 3 milliamps of current per sq ft of casing."

By R. A. Wagstaff

SINCE the time of the early Egyptians, the use of copper has been a boon to the life of most of the civilized world. Its use has been varied; in many connections, the art by which it attained its greatest usefulness has been lost. In this paper an endeavor will be made to take into consideration some of the many changes that have occurred during the last 40 years of copper-smelting operations. During that period the copper blast furnace has been almost forced out of existence by new methods of ore concentration-first, gravity concentration, and then flotation. These new methods of concentration introduced many new factors into the metallurgy of copper. The product was wet, it was fine and it was high grade. To overcome all these factors many changes have been necessary throughout the smelting agenda. New equipment has been necessary for transportation, unloading, sampling, bedding and moisturing in all smelting plants, especially the custom smelter. During the early days of "flotation," little was known about filtering or the use of an alkaline circuit; often the concentrate going to the smelter contained 20 to 25 per cent moisture. It is easy to imagine the difficulty arising with a product of this nature when it had to be shoveled by hand labor. To meet these conditions, mechanical unloading and sampling devices were soon developed. In many instances such good progress was made that actual costs for handling this unfavorable product were lower than those formerly incurred on the old product. Today most sampling of copper ores and concentrates is being done by mechanical sampling, pipe or augur sampling, or shovel sampling. Where concentrates are uniform in metal content, a great many of the plants now use pipe or augur sampling. For spotty ores, the old shovel sample with cone and quartering during the final stages is still in use. Where big tonnages are handled, mechanical sampling of concentrates is being done, with satisfactory results. To curtail slow and tedious cutting and mixing procedure, mechanical mixing boxes, splitters and cutters are used to cut down labor costs. MILLING As crude ores become scarcer, the use of milling operations increases. The few crude ores that are still smelted are used as fluxing types. To use these ores finer grinding has been found advantageous. This has made for better bedding and fluxing conditions, which in turn makes for faster smelting, lower fuel consumption and better metal recovery. The degree of fineness is more or less determined by the nature of the product. Most plants have set a standard of through ¾ -in. mesh screen for roaster- reverberatory smelting and through ¾ in. mesh screen for converter fluxes. For some refractory ores; even finer grinding has been found to be advantageous for good reverberatory smelting.

Jan 1, 1944

By W. B. Braden

This paper presents a suitable method for predicting gas-free oil viscosities at temperatures up to 500F knowing only the API gravity of the oil at 60F and the viscosity of the oil measured at any relatively low temperature. The API pravity and the one viscosity value are used as parameters to determine the slope of a straight line on the ASTM slanaord viscosity-temperature chart. Then, knowing the slope of the line and one point on the line, the vrscosities at higher temperatures can be determined. The line slope correlations were developed at I00 and 210F since viscosity data are frequently measured at these temperatures. A procedure is given for predicting line slopes from measurements at other tetnperatures. A nomogram is furnished for solving the relationship. The correlation has been evaluated at temperatures up to 5OOF for oils varyzng in gravity from 10 to 33 " API. The correiution is applicable only to Newtonian fluids. Comparison at 500F of true viscosities and those predicted from values at 100F shows an average deviation of 3.0 per cent (maximum deviation of 6.0 per cent). Predictions from the values at 21 0F for the same oils how an average deviation of 1.5 per cent (maximum deviation of 3.4 per cent). INTRODUCTION Correlations have been developed by Beal' and by Chew and Connally' for predicting viscosities of gas-saturated oils at reservoir conditions. Each of these correlations requires a knowledge of the solution gas-oil ratio and the viscosity of the gas-free oil at the reservoir temperature. For temperatures below 350F, measurements of the gas-free oil viscosities can be made easily using commercially available equipment. In thermal recovery processes, however, reservoir temperatures well in excess of 350F are encountered. Viscosity measurements at such conditions are more difficult and time consuming and require modification of existing equipment or the construction of new equipment. Measurements are further complicated by the difficulty of handling highly viscous oils associated with thermal recovery processes. Therefore, it is desirable to have a correlation which allows accurate prediction of viscosities at high temperatures. A commonly used technique for predicting viscosities at high temperatures is to measure the viscosities at two lower temperatures, plot the values on ASTM standard viscosity-temperature charts and extrapolate to the temperatures desired. If either of the values is slightly in error, the extrapolated value can be significantly in error. To justify an extrapolation, three points are actually necessary. This procedure can consume much time, particularly with heavy oils. Considering the cost of viscosity measurements, it would be desirable to eliminate the need for direct measurements by having correlations which would allow viscosity predictions from other physical or chemical properties. Beal1 investigated the possibility of correlating viscosity with oil gravity at temperatures from 100 to 220F. While showing that a general relationship exists, he also found significant deviations. It is possible that correlations will be developed based on oil composition as more information becomes available. While not eliminating the need for viscosity rneasurements, the method presented herein requires that only one viscosity measurement be made. The API gravity must also be known. The theory is based on the fact that the viscosity of paraffins (high gravity) changes less with temperature than does the viscosity of naph-thenes or aromatics (low gravity). The gravity. therefore, is used as a parameter to determine the slope of a straight line on the ASTM standard viscosity-temperature charts. The correlation is applicable only to Newtonian oils, and deviations due to thermal decomposition and nonhomo-geneity cannot be predicted. Oils containing additives have not been evaluated. PROCEDURE Fifteen oils were used in developing the correlation; eight were crudes and seven were processed oils. Oil gravities varied from 9.9" API (naphthene base) to 32.7' API (paraffin base). The temperature range studied was 81 to 516F. Each oil used had a minimum of three viscosity measurements and each plotted essentially as a straight line on the ASTM charts. In all, 91 viscosity measurements were used in the correlation. Saybolt, rolling ball and capillary tube viscometers were used for the measurements. Viscosity data for Samples 1, 2, 4, 7, 10, 11 and 14 were obtained in Texaco, Inc. laboratories. The data for Samples 3, 5, 6, 8, 9, 12 and 15 were from Fortsch and Wilson,3 and data for Sample 13 were from Dean and Lane.' All data points used in the correlation are plotted in Fig. 1. It is seen that some of the viscosity values deviated slightly from the straight-line plots at the higher temperatures. Properties of the oils after exposure to the

Jan 1, 1967

By A. B. Tanner

The effects of radon in drillholes on gamma-ray logs have been described by L. S. Hilpert and C. M. Bunker1 Since these effects may cause drastic error in the evaluation of uranium deposits, it is useful to know the conditions under which significant amounts of radon tend to accumulate in drillholes. In the studies described here, atmospheric conditions were found to dominate in the control of the behavior of radon in drillholes in the vicinity of a uranium orebody. The site of the investigation was in McKinley County, New Mexico, about 12 miles north of Grants. Drillholes of 4 1/4-in. diam, on 25-ft and 100-ft centers, penetrate ore in dry rock at a depth of about 100 ft. A geologic log of the drillhole of primary interest is shown in Fig. 1. Gamma-ray logs revealed three zones of ore-grade mineralization in the Todilto limestone. A 6-ft zone, the lowest of the three, assayed 0.20 pct U3O8 by chemical analysis. The limestone ores in this area contain disseminated uraninite and some yellow and orange secondary minerals. Only radon"", a member of the uranium'" series, was measured in this investigation. Radon is one of the chemically inert noble gases and is radioactive by alpha particle emission with a half life of about four days. In this discussion, amounts of radon are expressed in microcuries (1 microcurie equals 37,-000 disintegrations per sec) and concentrations of radon are expressed in microcuries per liter of drillhole air. Samples of air were obtained by lowering a sampling device (Fig. 2) into a drillhole and actuating the device at the desired depth. It was then raised to the surface and the sample was transferred to a storage tube. Within two days the sample was transferred to an ionization chamber, and the activ- ity of radon and its short-lived daughter products was measured at radioactive equilibrium with a vibrating-reed electrometer. The measurements were corrected back to the time of collection and involve errors estimated generally not to exceed + 5 pct to —15 pct. Radon Behavior in a Covered Hole: Fig. 3, a typical log of radon concentration vs depth in the covered drillhole, was made by using values of radon concentration at discrete depths. Continuous logs of alpha-particle radiation in the drillholes showed that such radon logs depict the continuous variation of radon concentration with depth quite accurately. Three features of radon logs were noted: 1) maximum

Jan 1, 1960

By Vincent T. Ricca, Kurtis Chow

When dealing with acid mine drainage as to treatment levels, costs, and evaluation of abatement schemes, predictions of the quantity and quality of the discharges are needed. An acid mine-drainage model is presented in this paper. In essence, the model is a hybrid of computer programs for stream flow simulation and acid mine drainage. Two major aspects of the model are discussed: mine-water generation and acid-load production. The former is based on hydrologic concepts and the latter on pyrite oxidation kinetics and oxidation product removal. The total model is programmed for the high-speed digital computer. The major inputs are: climatological, basin characteristics, and mine characteristics data. By the use o f the hydrologic model the amount of water that flows through the pyritic system is determined. From this information, acid loads removed by leaching, inundation, and gravity diffusion are then predicted. The outputs from the total model are: average daily mine-water discharge, the associated acid concentration or load, plus the average daily flow in the receiving streams or at basin outlets. The capabilities of the separate models have been tested individually and the joint model has been applied to a small drift mine in southeastern Ohio.

Jan 1, 1975

By John D. Roach

DURING an investigation of the yttrium-hydrogen system aimed at producing solid yttrium hydride specimens containing various amounts of hydrogen, it was observed that yttrium containing approximately 2 wt pct H exhibited a tendency to crack and crumble to a powder on standing in air at room temperature. It was also observed that longer hydriding times, at a given temperature, increased this susceptibility to powdering without an increase in hydrogen content, also that moisture in the air is necessary for the observed effects to occur. Even if cracking did not occur, there was a continual formation of a light gray powder on the as-treated surface of the hydrided yttrium and this reaction continues until the entire hydrided piece has been reduced to a powder. Storing the hydrided specimens in the absence of air or removing the surface either by machining or grinding were effective means of preventing this disintegration of hydrided yttrium. In an attempt to determine the reason for this powdering phenomenon, the surfaces of a number of as-hydrided yttrium specimens were examined by X-ray techniques. In all cases the X-ray pattern obtained showed the major phase to be yttrium hydride (YH2) as would be expected since the specimens contained 2 to 2.2 wt pct H. In some cases a trace of yttrium oxide was observed. There was also a third phase present on the surface of these hydrided specimens which could not immediately be identified. This unknown phase was a face-centered cubic material, NaC1-type structure, with a lattice parameter of 4.855 and a calculated density of 5.914 g per cc. Very slight hand polishing of the surface of the hydrided yttrium specimens completely removed both the unknown phase and the traces of oxide so that only the yttrium hydride pattern remained. Based on the X-ray patterns the quantity of the unknown phase on the surface of the hydrided yttrium appeared to be directly related to the susceptibility of the material to powdering. Work at the Denver Research Institute on the yttrium-nitrogen binary system showed that yttrium nitride (YN) is a face-centered cubic material with a lattice parameter of 4.878A and a density of 5.890 g per cc. They also noted that this compound rapidly disintegrated to a powder on standing in air. The unknown pattern observed in the above specimens corresponds very closely to that of the nitride—fcc structure, 4.885 parameter, and density of 5.914 g per cc. The presence of this thin film of nitride on the surface of the hydrided specimens probably accounts for the observed powder formation and crumbling. The nitride reacts with the water vapor in the air (verified by private communication from Dr. C. Huffine, General Electric Co.) to yield yttrium oxide and ammonia. Ammonia is readily detected when hydrided yttrium specimens were allowed to stand in bottled moist air. The powder formed on the surface of the hydrided specimens was shown by X-ray analysis to be yttrium oxide. This reaction appears to occur primarily at the grain boundaries since discrete particles of yttrium hydride separate from the specimens during this powdering process. The reaction of yttrium nitride with water vapor is believed to be as follows: 2YN + 3H2O - Y203 + 2NH3. Despite the fact that this nitride is present only as an extremely thin surface film, if the above reaction is not prevented by removing this film from the surface either by machining or grinding, the reaction continues until the entire hydrided piece has been reduced to a powder. To account for this continuation of the reaction, it is believed that the following reactionalsooccurs: 2YH2 + 2NH3 -2YN + 5H2. The nitride produced by the latter reaction reacts in turn with water vapor. The reaction therefore becomes autocatalytic and continues until the hydride has been consumed and the entire piece reduced to oxide powder. The amount of nitride required to initiate this reaction is quite small and this nitrogen contamination can occur from a number of sources—hydrogen gas employed, minute leak in the hydriding apparatus or even from degassing of the reaction vessel itself. Longer hydriding times increase the possibility of nitrogen contamination and this is especially true when a dynamic gas system is employed in the hydriding process. The production of stable, solid hydrided yttrium is dependent on the complete absence of nitrogen contamination during processing. If such contamination does occur, powdering of the hydrided product can be prevented by removing the nitride from the surface e.g. grinding or by preventing access of air to the pieces e.g. sealing in wax or plastic. The author wishes to express his appreciation to General Electric Co. for sponsoring this research and for permission to publish the results of work under Subcontract AT-93.

Jan 1, 1962

By William A. Kennedy, Jonathan R. Stahl

This paper deals with the phenomenon of water held in a leach dump due to capillarity. Water is shown to be retained in the fine pores of the ore as well as in the interstices between the rock and soil particles. Upon drainage, Chino leach dump material shows two distinct capillary systems and a double capillary curve is often obtained. Both the igneous and the sedimentary rocks composing the leach material are shown to have appreciable porosity but little permeability. Fluid flow is, therefore, restricted to the interstices between the rock and soil particles. The irreducible water saturation for the aggregate is found to be 884 for the -48 mesh material and 235 for the448 mesh to one inch material. The composite sample of minus one inch dump material had an irreducible water saturation of 52 percent. The irreducible water saturation in the fine pores of the ore was found to be between 73 and 76 percent. Very coarse pores or channels between large rocks exhibit essentially zero capillary retained water. The presence of fine material in a dump can cause high water saturations to be retained and these saturations may be mistaken for perched water tables. Perched water tables can be drained but capillary water will be retained. Capillary pressure data can aid in distinguishing between perched water tables and capillary retained water.

Jan 1, 1974

By H. B. C. Nitze

A description of some of the magnetic ore-deposits in this region should be of interest to the mining and metallurgical public, inasmuch as very little has been said or written concerning them. I refer to the magnetite deposits of Franklin and Henry counties, Va., and of Stokes county, N. C. These deposits remained comparatively unexplored until recently, when the construction of the Roanoke & Southern R. R. through this territory has called attention to them, by furnishing the means of transportation for the ores. It is true that the ores have long been known, at least locally, and were smelted in catalan forges and old-fashioned, cold-blast charcoal-furnaces long before and during the late war. At the present time, however, the old workings are caved in, filled up and over-grown to such an extent that, as a rule, but little can be learned from them. No prospecting of any consequence has been done, and as my time was too limited and the territory to be examined too extensive to permit additional openings of a more satisfactory nature to be made, the incormpleteness of some of the data I have to offer (notably, those referring to the absolute width of the veins) will be pardoned. It will hardly be necessary to say that this ore-bearing formation belongs to the Archaean, or Eozoic age, the usually occurring rocks being schist, shale, gneiss, granite, sandstone and quartzite. The stratigraphy is, as a rule, quite regular (excepting in the Danbury section, Stokes county, N. C.), the general strike being northeast and southwest, and the dip nearly vertical. The country is gently roll-

Jan 1, 1892

By C. H. Mathewson, P.W. Bakararian

The greatcr part of the literature on the plastic behavior of magnesium dates back to that active period of research in crystal mechanics immediately following the widespread preparation of isolated metallic crystals large enough for the application of conventional methods of mechanical testing. These investigations, performed on single crystals, revealed an analogy between zinc and magnesium with respect to their fundamental mode of deformation. in the operation of glide and twinning, respectively, on crystallographically similar planes. Mathewson and Phillips (1928)' by geometrical analysis identified the plane in magnesium as the twinning plane. Schiebold and Siebel (1931) confirmed this twinning planc, established the basal plane as the plane of slip, and a digonal axis I as the slip direction. They also rcported twin formation in a secondary role on the {IOI} plane. Schmid (1931)³ summarized and discussed the earlier evidence and presented the results of his own experiments on the effect of temperature and small amounts of soluble elements. From X-ray studies on extended wire single crystals, he concluded that slip along the basal plane in the direction of the digonal axis I closest to the stress direction was the sole slip system operating at atmospheric temperature. This conclusion was based on experiments with crystals of many different orientations relative to the stress axis. Special attention was directed to the basal plane and the digonal axis I, as the plane and direction of greatest atomic density. Determinations of resolved shear stress at the onset of plastic yielding-—i.e., the critical resolved shear stress—were also made; the average of these calculations showing 82.9 grams per sq. mm. This value varied only slightly up to 300°C. at which temperature it was found to decrease to 70.5 grams per sq. mm. The extension of his crystals at temperatures above 225°C. further disclosed the presence of new slip systems. After the origince specimens of circular section had been

Jan 1, 1943

By C. H. Mathewson, P. W. Bakararian

The greatcr part of the literature on the plastic behavior of magnesium dates back to that active period of research in crystal mechanics immediately following the widespread preparation of isolated metallic crystals large enough for the application of conventional methods of mechanical testing. These investigations, performed on single crystals, revealed an analogy between zinc and magnesium with respect to their fundamental mode of deformation. in the operation of glide and twinning, respectively, on crystallographically similar planes. Mathewson and Phillips (1928)' by geometrical analysis identified the plane in magnesium as the twinning plane. Schiebold and Siebel (1931) confirmed this twinning planc, established the basal plane as the plane of slip, and a digonal axis I as the slip direction. They also rcported twin formation in a secondary role on the {IOI} plane. Schmid (1931)³ summarized and discussed the earlier evidence and presented the results of his own experiments on the effect of temperature and small amounts of soluble elements. From X-ray studies on extended wire single crystals, he concluded that slip along the basal plane in the direction of the digonal axis I closest to the stress direction was the sole slip system operating at atmospheric temperature. This conclusion was based on experiments with crystals of many different orientations relative to the stress axis. Special attention was directed to the basal plane and the digonal axis I, as the plane and direction of greatest atomic density. Determinations of resolved shear stress at the onset of plastic yielding-—i.e., the critical resolved shear stress—were also made; the average of these calculations showing 82.9 grams per sq. mm. This value varied only slightly up to 300°C. at which temperature it was found to decrease to 70.5 grams per sq. mm. The extension of his crystals at temperatures above 225°C. further disclosed the presence of new slip systems. After the origince specimens of circular section had been

Jan 1, 1943

By C. H. Samans, G. F. Tisinai, J. K. Stanley

The addition of nitrogen (0.10 to 0.20 pct) to Fe-Cr-Ni alloys of simulated commercial purity results in a real displacement of the u phase boundaries to higher chromium contents. The effect is small for the (Y + s)? boundary, but is pronounced for the (y + a +s)/(y + a) boundary. Although there is an indication of an exceptionally large shift of the n boundaries to higher chromium contents, especially in steels with nitrogen over 0.2 pct, the major portion of this apparent shift results from the fact that carbide and nitride precipitation cause "chromium impoverishment" of the matrices. The effect of combined additions of nitrogen and silicon to the Fe-Cr-Ni phase diagram is demonstrated also. Nitrogen can nullify the effect of about 1 pct Si in shifting the (y + o)/? phase boundary to lower values of chromium at all nickel levels from 8 to 20 pct. NItrogen can nullify this U-forming effect of about 2 pct Si at the 8 pct Ni level, but not at the 20 pct Ni level. The alloys studied were in both the cast and the wrought conditions. There are indications that the u phase forms more slowly in the cast alloys than in the wrought alloys if both are in the completely austenitic state. The presence of 6 ferrite in the cast alloys accelerates the formation of U. Cold working increases the rate of o formation in both cast and wrought alloys. THE major improvement in Fe-Cr-Ni austenitic alloys in recent years has been in the addition or removal of minor alloying elements to facilitate better control of corrosion resistance, sensitization, and heat resistance. One shortcoming of the austenitic Fe-Cr-Ni alloys, which never has been completely circumvented, is their propensity toward u formation. In the AISI-type 310 (25 pct Cr-20 pct Ni) and type 309 (25 pct Cr-12 pct Ni) steels, sufficient amounts of u phase can form, if service or treatment is in a suitable temperature range, to cause severe embrittlement. Also, there is a growing conviction that this phase may be contributory to some unexpected decreases in the corrosion resistance of certain of the 18 pct Cr-8 pct Ni-type steels. The present paper discusses the effect of nitrogen additions on the location of the (r+u)/d and the (y+a+u)/(y+a) phase boundaries in the ternary Fe-Cr-Ni system, for cast and wrought alloys of simulated commercial purity, and in similar alloys containing up to about 2.5 pct Si. The objective is to define compositional limits for alloys which will not be susceptible to u formation when used near 1200°F (650°C). An excellent review of the early studies of the u phase in the Fe-Cr-Ni system has been compiled by Foley.1 Rees, Burns, and Cook2 have determined a high purity phase diagram for the ternary system, whereas Nicholson, Samans, and Shortsleeve3 are- stricted themselves to a portion of the simulated commercial-purity phase diagram. Both groups of investigators show almost an identical position for the commercially significant (y+u)/y phase boundary. Further comparison of the work of the two groups indicates that, below the 8 pct Ni level, the commercial alloys have a decidedly greater propensity toward u formation than the high purity alloys. The two groups of workers agreed that both the AISI-type 310 (25 pct Cr-20 pct Ni) and the type 309 (25 pct Cr-12 pct Ni) steels are well within the (y+~) region and that the 18 pct Cr-8 pct Ni-type alloys straddle the U-forming phase boundaries. Nicholson et al.3 showed, in addition, that these boundaries shift toward lower chromium contents if greater than nominal amounts of silicon or molybdenum are added. The effect of nitrogen on the location of the s phase boundaries in the Fe-Cr-Ni system has not been known with any certainty. In 1942, an approach to this problem was made by Krainer and Leoville-Nowak,' but at that time they apparently were unaware of the slow rate of s formation in strain-free samples and aged their samples for insufficient times, e.g., 100 hr at 650°C (1200°F) and 800°C (1470°F). For this reason, it would be expected that their (y+ u) /y boundary would be shifted toward lower chromium contents (restricted ?-field) when equilibrium conditions were approximated more closely. Procedure for Studying the Alloys The alloys used were prepared in the following way: Heats of 200 lb each were melted in an induction furnace. A 5 lb portion of each heat was poured into a ladle containing an aluminum slug for de-

Jan 1, 1955

By C. E. Birchenall, G. Derge

IN studying the kinetics of slag-metal reactions, it has become increasingly apparent that a complete knowledge of all aspects of interface phenomena will be required to clarify these processes adequately. A part of the data required for all oxidizing slags used in the refining of impure iron to steel is the rate of exchange of iron between the slag and metal phases. The simplest equilibrium of this type is that between liquid iron and iron silicate slag when both phases are equilibrated with the silica crucible containing them. In this study, the exchange of iron between the two liquid phases has been measured by using radioactive Fe as tracer. The observed high exchange rate indicates the ease with which such interfaces may be crossed in refining processes. The experiments required for this study involved relatively minor and normal modifications of well established techniques. Melting was accomplished by induction heating in heavy walled, fused silica, rotating crucibles." Rotation was used to minimize dilution of the slag by crucible erosion. The melting stock was ingot iron. Slags were prefused in iron crucibles using chemically pure grade oxide reagents. The special conditions applying to the active iron additions will be described for individual experiments. Suitable precautions were observed with regard to protection against radiation hazards.' Identification of Activity This particular study was initiated several years ago, but held in abeyance because the radioactive iron available at that time contained a foreign activity which concentrated in the slag so as to mask the iron activity and render the results unin-terpretable. With the benefit of experiences from other studies, radioiron of suitable purity can now be prepared. As received from the Isotope Div. of A.E.C., the unit appears to contain Fe + Fe50 and a high activity cobalt. The cobalt and iron are separated by repeated ether extractions, and the purified iron stored for sufficient time for the Fe'7 44 day half-life) to decay to negligible activity, leaving only Fe as the active isotope. This was confirmed by the absorption curves for slag and metal samples from heat No. 1. In Fig. 1 the experimentally measured points for the absorption curves of slag and metal are fitted by the calculated slope of 5.8 mg per sq cm in aluminum, which corresponds to the Mn K doublet emission resulting from the capture of an orbital electron of Fe" by the nucleus. This shows that the radioactive species are the same in both slag and metal and identifies it as Fe55 Description of Individual Heats For the first heat, the radioactive iron was contained in the prefused slag. The active Fe55 had been precipitated with carrier and was added as Fe2O3 during fusion in the iron crucible. The charge of 500 grams of ingot iron was melted, the protective iron sleeve added, rotation started, and a prefused, inactive slag was added to allow the system to approach equilibrium. After about 5 min at temperature, the wash slag was skimmed and the active slag added. Initial slag and metal samples were taken as soon as the slag was molten. Additional samples were taken at indicated intervals thereafter. Slag samples were dipped with a small iron spoon and metal samples were sucked into 1/4 in. ID silica tubes. The slag and metal samples were pulverized and mounted for radioactive counting. The slag samples were analyzed chemically for FeO. Temperature was read after the last slag sample by immersion of a Pt-Pt-Rh thermocouple protected by a fused silica sheath. Since no significant variation of rate with temperature was observed

Jan 1, 1954

By Maynard H. Jameson

Earlier investigations of the potential-drop-ratio method of electrical prospecting have indicated that under suitable conditions this method is well adapted to the location of formation boundaries in stratified ground. A description of this development was given several years ago by H. Lundberg and Th. Zuschlag.l The curves published by these authors for the potential-drop-ratio variation above a horizontal contact indicated a definite relation of the position of the curve peak to the depth of the interface. The theory underlying this relation was subsequently studied by Z. Mitera in greater detail,' and the theoretical deductions were compared with the results of tank experiments. The investigations available at this writing were confined to studies of horizontal formation boundaries. It is the purpose of this paper to extend the scope of the previous work to the problem of dipping layers. Theory Consider the case of three media of different resistivities, whose interfaces are not parallel. If a point-source is located in one of these interfaces, its images do not lie in a straight line, but on the circumference of a circle whose center is at the hypothetical junction of the interfaces. R. F. Aldredgea determined the relation that exists between the degrees of dip of the two interfaces and the distances between the various images and the point for which the potential is to be found. As seen in Fig. I, three media of resistivities PO, p1, and p2 are involved, and the source I is located at the interface of the media Coo) and (p1). The perpendicular depth of the lower interface is h, 0 is the dip, R is the distance between source I and potential point P, and r is the distance between the images and that point. To distinguish between images lying above the ground interface and those below, the notation "odd" and "even" images will be employed; images below the ground interface will be termed "odd" and those above "even." The following relations govern the distances between either kind of images and the potential point: EvEn Odd Ta — R r1 - [rl] - [RS + 4h(h + R sin 01½ r, = [r] =. [R1 + 4h cos 0)2(h + -R sin 0)1½ ri - [r3] ={r3} [R* + 4h(4 cos2 0 - i)1 (h + R sin 0)l½ r4 = [r4] = [R2 + 4h(4 cos $ cos 30)1 (h + R sin 0)]½ r, — [r4] - [R2 + 4h(4 cos9 R cos 20 + cos 48)2 (h + R sin 01½ I RI + 4h[2 cos 30(4 cos2 0 - I)12 (h + R sin 8)1 ½ rn - [r4] - [R2 + 4hlf(cOs 0)18(h + R sin R)l½ As previously pointed out, the images of the source are on the circumference of a circle. If the angle of dip is 0, the angle measured from the horizontal to the first image is 28; to the second image it is 48, and so on. Since the limit of the reflecting interface is at its outcrop, the last possible

Jan 1, 1946

By Maynard H. Jameson

Earlier investigations of the potential-drop-ratio method of electrical prospecting have indicated that under suitable conditions this method is well adapted to the location of formation boundaries in stratified ground. A description of this development was given several years ago by H. Lundberg and Th. Zuschlag.l The curves published by these authors for the potential-drop-ratio variation above a horizontal contact indicated a definite relation of the position of the curve peak to the depth of the interface. The theory underlying this relation was subsequently studied by Z. Mitera in greater detail,' and the theoretical deductions were compared with the results of tank experiments. The investigations available at this writing were confined to studies of horizontal formation boundaries. It is the purpose of this paper to extend the scope of the previous work to the problem of dipping layers. Theory Consider the case of three media of different resistivities, whose interfaces are not parallel. If a point-source is located in one of these interfaces, its images do not lie in a straight line, but on the circumference of a circle whose center is at the hypothetical junction of the interfaces. R. F. Aldredgea determined the relation that exists between the degrees of dip of the two interfaces and the distances between the various images and the point for which the potential is to be found. As seen in Fig. I, three media of resistivities PO, p1, and p2 are involved, and the source I is located at the interface of the media Coo) and (p1). The perpendicular depth of the lower interface is h, 0 is the dip, R is the distance between source I and potential point P, and r is the distance between the images and that point. To distinguish between images lying above the ground interface and those below, the notation "odd" and "even" images will be employed; images below the ground interface will be termed "odd" and those above "even." The following relations govern the distances between either kind of images and the potential point: EvEn Odd Ta — R r1 - [rl] - [RS + 4h(h + R sin 01½ r, = [r] =. [R1 + 4h cos 0)2(h + -R sin 0)1½ ri - [r3] ={r3} [R* + 4h(4 cos2 0 - i)1 (h + R sin 0)l½ r4 = [r4] = [R2 + 4h(4 cos $ cos 30)1 (h + R sin 0)]½ r, — [r4] - [R2 + 4h(4 cos9 R cos 20 + cos 48)2 (h + R sin 01½ I RI + 4h[2 cos 30(4 cos2 0 - I)12 (h + R sin 8)1 ½ rn - [r4] - [R2 + 4hlf(cOs 0)18(h + R sin R)l½ As previously pointed out, the images of the source are on the circumference of a circle. If the angle of dip is 0, the angle measured from the horizontal to the first image is 28; to the second image it is 48, and so on. Since the limit of the reflecting interface is at its outcrop, the last possible

Jan 1, 1946

By L. Thomassen, N. Spooner, J. M. Thomas

NI-CR and some Ni-Cr-Fc alloys, when used as electrical resistance heating elements in reducing atmospheres, at times suffer rapid breakdowns due to so-called "green rot." These reducing atmospheres are most frequently used in bright annealing and heat-treating furnaces which are kept for long periods of time at 1500' to 1800°F. The green rot is a preferential oxidation of the chromium in the alloy to such an extent that the remaining metal frequently becomes ferromagnetic. The Curie point (magnetic transition point) at room temperature for a pure Ni-Cr alloy is known to be at about 7 pct Cr.¹ This represents a severe loss in chromium for one popular grade of resistance alloy, which is nominally 80 pct Ni-20 pct Cr. The formation of oxides along the grain boundaries makes the ribbon brittle and gives the fracture a green, earthy appearance—hence the name. The authors have studied this phenomenon, simulating the industrial conditions by heating resistance ribbons in various reducing atmospheres, such as moist hydrogen or the atmosphere specified in the ASTM test.² This atmosphere contains 16 pct H2, 10 pct CO, 4 pct C02, 1 pct CH1, 1.5 to 2.5 pct H2O, balance N2. Little success was had in producing severe corrosion with the commercial 80 pct Ni-20 pct Cr alloys. It had been noticed, however, that 90 pct Ni-10 pct Cr alloy wires deteriorated very rapidly when placed in the bottom of narrow thermocouple protection tubes. The bottoms of the tubes with the wires were heated in air. This took place both in porcelain tubes and in Inconel* tubes either with the cold end open or loosely stoppered with asbestos. On examination the wires showed microstructures which would be classified as green-rot corrosion. Subsequent investigations with various alloy wires confirmed the observation that corrosion occurred in some wires, including 80 pct Ni-20 pct Cr alloys, much more rapidly in such tubes than had occurred previously in test atmospheres mentioned above. When 90 pct Ni-10 pct Cr alloys are oxidized with an abundant air supply, the oxide coat consists of both nickel and chromium oxides. In this case thermodynamic equilibrium between the oxides is not established. However, when oxidized 90 pct Ni-10 pct Cr alloy specimens were heated to 1500" to 1800°F inside small diameter tubes, the oxide coat transformed to a bright metallic outer layer of nickel or nickel-rich alloy, beneath which appeared a green oxide, followed by intergranularly attacked metal. The obvious explanation is that in the narrow tubes, thermodynamic equilibrium is being established according to the equation NiO + Cr (in alloy) ? Ni + Cr2O3 This reaction is favored due to the fact that the oxygen pressure over nickel oxide is more than 10"' times the oxygen pressure over the green chromium oxide. The initial oxygen in the tubes is depleted very rapidly by oxidation of the wire and of the tube, if it is metallic. A confirmation of the occurrence of the reaction, reduction of NiO by the chromium in the alloy, was obtained by putting oxidized nickel foil into an evacuated quartz tube along with a piece of bright 90 pct Ni-10 pct Cr alloy ribbon, and heating the tube at 1820°F for a number of hours. The nickel oxide on the foil was completely reduced to pure nickel, leaving a bright foil. The 90 pct Ni-10 pct Cr alloy became strongly magnetic and showed the typical green-rot structure. Weights of the samples before and after testing showed the weight loss of the foil to approximately equal the weight gain of the ribbon. Evidently the bottom of long, narrow protection tubes, stoppered or not, may under certain conditions act just as the sealed quartz tubes in respect to being a confined space in which oxygen is not freely replenished. This condition of oxygen depletion can be prevented by introducing a small amount of air into the bottom of the tube. Many conditions becloud the green-rot phenomenon, such as carburization, sulphidization, and the presence of other corrosive agents. However, these experiments have shown that the basic reaction is a case of internal oxidation which can occur simply by adjusting the oxygen pressure to a low enough level so that the atmosphere will leave the nickel intact and oxidize the chromium. The action of the other agents in commercial atmospheres can then be taken up as individual cases. From these and numerous other tests completed to date or still in progress, it is believed that a more critical evaluation of electrical resistance alloys for their resistance to green-rot corrosion can be made. A much better understanding of the mechanism for this type of corrosion should also result. A more complete report on these experiments will be published later. In the May 1953 issue: TP 35213 Discussion: Solubility of Carbon and Oxygen in Molybdenum by W. E. Few and G. K. Manning, discussion by N. A. Gokcen: p. 747, first column, the fifth, sixth, and seventh lines should be the first, second, and third lines, followed by the present first, second, third, fourth, eighth, ninth, and tenth lines.

Jan 1, 1954

By Frederic Brunton

I. INTRODUCTION THE smelting plant of the British Columbia Copper Co. at Greenwood, B. C., now closed because of the decline in the price of copper due to the European war, is of special interest to metallurgists for several reasons. It was successfully smelting in blast furnaces the lowest grade copper ore of all plants in America. In order to do so, it had to run at' very high efficiency, which necessarily required a large tonnage per square foot of hearth area, together with the minimum amount of labor and other costs. The furnaces smelted daily 2,250 tons of ore (6.62 tons per sq. ft. of hearth area), carrying 0.85 per cent. of copper, at a smelting cost of $1.18 per ton. The entire plant required 130 men to operate it and keep up repairs, showing a labor efficiency of about 17.5 tons per man per day. In the present paper, the method of obtaining these results is shown. Most of the information contained in this description I obtained as Assistant Superintendent, during the two years preceding the present shutdown. Other sources of information to which I am indebted are: The British Columbia Copper Co., Ltd., by Alfred W. G. Wilson, in The Copper Smelting Industry of Canada; Greenwood Smelting Works, by J. E. McAllister, Engineering and Mining Journal, vol. xci, pp. 1011 to 1015 (May 20, 1911); and Description of the Copper Smelter of The British Columbia Copper Co., by W. L. Bell, in Transactions of the Canadian Mining Institute, vol. xvi, pp. 151 to 154 (1913).

Jan 7, 1915

By Lyall Zickrick

As a result of the studies on recrystallization and crystal growth made in this laboratory, certain theories have been developed. These are expressed briefly in a paper by Dean and Hudson.1 One of the principal points brought out in that paper is that in the deformation of a crystal, the energy supplied is distributed to the atoms of the lattice, probably by the forced formation of molecules. It is found that a Maxwellian distribution of the energy among these atoms will account for the grain growth at various temperatures. According to such a distribution the number of atoms with energy above a certain critical value, E, necessary for recrystallization at the absolute temperature T is given by n Ne(-E/kT) where N is the total number of atoms. It is apparent that if this line of reasoning is correct, a metal which has been cold-worked and reheated to a temperature below that of complete annealing will have the atoms with the higher energy recrystallized, that is, reduced to normal energy and there will remain only atoms below a certain energy. If this metal is again cold-worked the peak in the number-energy distribution curve will be displaced toward the regions of lower energies, that is, higher temperature of recrystallization. By a repetition of this process the position of this maximum and hence the recrystallization temperature of the metal could be raised considerably. In order to' check this theory, experiments have been made on copper wire. The wire was drawn from 1/4-in. rod to 22 B & S gage and then sample lots were annealed at 400 and 220° C., respectively. The wire annealed at 400° C. gave an elongation of 34 per cent., whereas that annealed at 220° C. gave only 23 per cent. These wires were then drawn by identical practice to 34 B & S gage and the elongation determined after an anneal of 3 mm. in an oil bath held at various temperatures.

Jan 1, 1927