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Established as a Division November 17, 1948 B W Gonser, Chairman J C Kinnear, Jr, Past Chairman H H Kellogg, Chairman-Elect R C Cole, Vice-Chairman, '58 A E Lee, Jr, Vice-Chairman, '59 W R Opie, Vice-Chairman, '60 R W Shearman, Secretary AIME, 29 West 39th Street New York 18, N Y

Jan 1, 1957

Book Review MANAGEMENT AND MEN. By Meyer Bloomfield, Boston. The Century Co., New York, 1919, pp. 584, H.X. 5 1/2. $3.50. This hook is an exposition of English efforts to solve the problem of labor unrest in England. The first six chapters are reprinted from articles published in the Satur-day Evening Post, for whom the author went to England to study the problem at first hand. These articles deal with housing, increased production, eliminating the internal friction in the industrial machine and a chapter each devoted to the view-point of employer and employee. These chapters are written in the easily readable magazine style and give a complete general survey of the particular solution being tried. Perhaps their greatest., certainly not their least, worth lies in the fact that they form a vehicle for unusually voluminous appendices containing in full the famous Whitley Reports which are the basis of the new movement, together with various reports, which, except for this publication, would be largely inaccessible to those inter-ested in this country. The Whitley scheme considers each industry a unit and proposes to establish therein a Joint Standing Industrial Council composed of representatives of employers and employees to consider appropriate matters affecting the industry at large. There is to be a District Council for each industry which will, as its name implies, deal with the clatters pertaining to that interest in. the particular district. The third and last body in this scheme of Industrial Parliament is the Works Committee, which is com-posed of representatives of the management and of the workers employed in particu-lar plants or mines to act in close cooperation With the district quid national machinery. The Whitley or similar schemes have been tried in many communities in England and the book contains interesting comments on the result obtained, it being notable that most of the objections conic from plants which have not tried the scheme. Meyer Bloomfield, the author; is the specialist in industrial personnel problems who organized the industrial service activities of the United States Shipping Board, Emergency Fleet Corporation. P. E. B.

Jan 10, 1919

By William L. Russell

A new instrument for measuring bulk and grain vol-urnes is described, and compared in accuracy with two modifications of Nutting's method, All three methods are reasonably fast, and in all three the probable error in the determinations of bulk volume can be kept down to about 0.1 to 0.2 per cent. INTRODUCTION The new pycnometer described in this paper is designed to give speed without sacrificing accuracy. Some time ago Russell1 described a somewhat similar appa-ratus; however, the instrument described in the present paper is more accurate. Nutting' designed the pycnom-eter shown in Fig. 1 (A and B), and Pirson3 has shown points like those of Fig. 1-D. The procedure described in this paper for using Nutting's pycnometer has been modified from that used by Nutting. CHOICE OF LIQUIDS The best liquids for measuring grain volumes are hydrocarbons or chlorinated hydrocarbons which evaporate slowly. Trimethylbenzene or mesitylene, triethylben-zene, carbon tetrachloride, and tertalin have been used for this purpose. Any of these liquids or mercury may be used for measuring bulk volume. PREVENTING ERRORS DUE TO INVASION OF LIQUID Errors due to the invasion of the porous, permeable bulk samples by the liquid of measurement may be prevented or greatly reduced by using mercury, by applying an impervious coating, or by soaking the bulk samples in the liquid of measurement until bubbles cease issuing from them. Errors are produced only by the invasion of the samples which occurs between movement when the samples are weighed in air and the moment the weight of liquid displaced by the sample in the pycnometer is determined. No error is produced by varying degrees of filling of the pore space of the samples by the liquid of measurement. The excess liquid should be wiped from the samples immediately before the weight in air W1, is determined, and they should be placed in the pycnometers immediately. OPERATION OF NEW INSTRUMENT The new pycnometer is shown in Fig. 2. It consists of two glass parts which fit together at a ground glass joint. The spaces J and D are connected by fine glass tubes E, and the space J must be larger than the space D by at least the volume of the largest sample to be tested. The projections H afford a grip for twisting when the two parts tend to stick together. The position of the sample in mercury is shown by I, and in other liquids by M. F is a permanent mark on the glass, and G is a tem-Some marker. In order to determine the position at which G should be placed, invert the instrument so that A is at the bottom, and fill space D. Place the cub K

Jan 1, 1958

By W. C. PAGE

HARVEY S. MUDD has the unusual distinction of having virtually inherited a Directorship in the -A.I.M.E., for he was appointed to the Board to fill the unexpired term of his father in 1926. Since then he has served as a Director continuously until 1936, and now he is a candidate for Vice-President. One of the first words that young Harvey tried to say was "ore," for he was born in Leadville, Colorado, in the heyday of that camp, where Seeley W. Mudd for years ran the Small Hopes mine. Stanford and Columbia gave him his mining education, and the Shattuck-Arizona, at Bisbee, his first job. Afterwards he examined many

Jan 1, 1937

Discussion of the paper of DORSEY HAGER, to be presented at the Colorado meeting, September, 1918, and printed in Bulletin No. 138, June, 191S, pp. 1109 to 1118. WALLACE E. PRATT, Wichita Falls, Tex. (written discussion*).¬Mr. Hager has touched upon interesting problems related to the broad subject with which he has entitled his paper. As to the existence of the important structural feature in the buried Bend series, which Mr. Hager constructs from well-logs, and designates as the "Bend Arch," there seems to be general agreement among a number of observers. Indeed, M. G. Cheney1 and Robt. T. Hill2 have each published structural maps of the Bend Arch that do not differ essentially from the map shown in Mr. Hager's Fig. 1. The reflection, in the overlying, unconformable Cretaceous, of certain folds in the Pennsylvanian, with which the petroleum accumulations has to do, is an important observation on the part of Mr. Hager, since, as he says, much critical territory is covered by Cretaceous, and it is highly desirable that the underlying Pennsylvanian structure be mapped, if possible. If the folds in the Pennsylvanian are of post-Cretaceous age, then it should be possible, in spite of the intervening unconformity, to determine approximately the position of buried folds beneath the Cretaceous overlap. The idea of post-Cretaceous folding would not be out of accord with the suggestion by Carroll H. Wegemann that the folding of the Permian beds in southern Oklahoma was still in progress as late as the Tertiary.3 But most observers have related the folds in the Pennsylvanian and Permian beds at the surface, both in North Texas and southern Oklahoma, to the process of. emergence of the land area at the end of the Permian. It seems more probable that the reflection of Pennsylvanian folds in the unconformable Cretaceous which Mr. Hager observed is due to long continued persistence of stresses which were largely relieved at the close of the Permian, than that the principal period of folding was post-Cre-taceous; this being the case, it seems likely that only folds of greatest intensity in the Pennsylvanian will, be decipherable in the Cretaceous overburden, and that many promising structural features are so concealed by the Cretaceous as to escape detection except by drilling.

Jan 8, 1918

By G. S. Cole, G. F. Bolling

ThE exact type of fluid flow which occurs in a solidifying ingot is important in determining subsequent grain structure. This has been shown in studies of natural Convection" and of forced stirring or other disturbances of the melt."16 We shall explicitly argue that a complement to the existing natural flow in an ingot should be more effective than other types of flow in promoting the columnar-to-equiaxed transition. The ultimate effects of fluid flow upon structure is one of the topics of solidification that we have investigated in the alloy system Pb-Sb, under conditions simulating casting. In Fig. 1, the essential features of a bidirectional growth apparatus are shown; horizontal freezing from water-cooled faces within a low-thermal-conductivity lavite boat is a reasonable simulation of an ingot section. Details such as the furnace and thermocouples are omitted in order to show the location of four permanent. magnets, each with a pole separation of 21 in. providing a central field of about 1000 Gauss. When coupled with a dc current imposed through appropriate connections made at the cooled faces, a flow of fluid is produced as shown schematically. This technique described by Pfann and ~orsi" is ideal for our purpose since the flow indicated is the same as that we observe to occur naturally in this system. Components of 99.999 pct purity were used for study and all due precautions were taken in alloy preparation to avoid contaminants. Sections of the specimens were taken to ensure results representative of the interior as well as the surface of specimens. All proportions of equiaxed and columnar regions were measured by tracing the etched grain structures onto graph paper and simply counting squares. Four alloys were examined at superheats of 40" * 5°C and 100" * 9°C. Preliminary tests had shown that no appreciable enhancement of structure was obtained with magnetic field alone, so that this condition is not reported; it should nevertheless be noted that other configurations of magnetic field will reduce convection and thus enhance columnar growth.'8 For the tests reported the magnetic field was applied to a specimen by bringing the four preassembled magnets to a position 2 mm from an outer tube immediately after the ingot was poured. The dc current of 30 amps passed through the sample throughout the entire solidification cycle, resulting in a power dissipation of 9 w per sq cm of interface. This may be compared to the evolution of latent heat of approximately 18 w per sq cm. Table I contains the results of this experiment in terms of the total area ratio, equiaxed/columnar grains, as a function of the field interactions, solute concentrations, and superheats employed. The total structure of the ingot is seen to be most influenced when both the field and current are applied simultaneously; when current acts separately, little effect may be noted in spite of the heat supplied. In addition, the change in structure from the no field-no current case to the field-current condition is more pronounced at the higher superheat, and the higher the concentration of antimony. An example of the grain refinement, as well as the increased equiaxed zone, is shown in Fig. 2. It is now important to prove that there is indeed an increase in fluid flow due to the presence of the field-current interaction; this is done by temperature measurements in the liquid metal. Let us consider a bidirectional casting in which heat is applied to and removed from the system, in such a way that rate of solidification is zero.* When a sensitive thermocouple

Jan 1, 1967

By R. V. Ramani, Robert Stefanko

The more stringent ventilation requirements of the 1969 Act have created a greater need for improved network analyses. More air is required at the last open crosscut (9000 cfm) and for the first time a minimum quantity is specified for the face (3000 cfm). Severe restrictions are placed on both belt and track haulage, and the intake air cannot contain more than 2 mg per cu m of respirable dust, to be reduced to 1 mg later. Larger tonnage and longer life mines are the trend today, necessitating multiple fans and shafts. Yet relatively little engineering goes into designing the mine ventilation system. In this paper a ventilation system is designed for a typical Pittsburgh block system, manual calculations are made and then checked by a computer solution. The computer is the ideal tool to try out proposed changes on paper to insure that the entire mine is properly ventilated and no costly adjustments need be made by dumping air. While it is theoretically possible to solve complex ventilation network problems by hand, it is not practical to do so because of the tremendous man-hours required and the many opportunities for errors. Thus the digital computer is indispensible to the ventilation engineer and newer improved ventilation programs are being developed to more realistically model mine ventilation networks. Suggested ventilation changes to comply with the new regulations are also critically evaluated.

Jan 1, 1973

By E. C. Harder

AT a Meeting of the New York Section, on May 23, 1918, the sole subject of discussion was the nature and occurrence of iron ores in certain parts of the world.? Owing to the importance of this subject, it has been deemed' advisable to publish the remarks made at that meeting in the form of a paper, for presentation at the Milwaukee Meeting, instead of in the usual place, under News of Local Sections. The remarks related to the following districts: Brazil, by E. C. Harder, of the U. S. Geological Survey; Scandinavia, by Waldemar Lindgren, of the U. S. Geological Survey; Cuba, by C. M. Weld, of the U. S. Bureau 'of Mines; Southern Europe, by A. C. Spencer, of the U. S. Geological Survey; China, by H. Foster Bain, of the U. S. Bureau of Mines; Alsace-Lorraine, by Sidney Paige, of the U. S. Geological Survey. BRAZIL By E. C. Harder During the years immediately preceding the war, the iron ores of Brazil were attracting the attention of iron operators both in Europe and in the United States. This was clue to the large quantities of practically undeveloped ore available, and to its great purity. It is reasonably safe to state that had capital not been diverted from the exploitation of these deposits to war purposes, Brazilian iron ores would probably now be offered in European and American markets. It is certain that after the war these ores will play a prominent part in the economic reconstruction of Europe and perhaps in the development of America.

Jan 9, 1918

By B. M. Larsen, T. E. Brower

In two previous paperslJ dealing with the carbon-oxygcn reaction, and the simultaneous content of each, in liquid steel in the furnace, we have made use of the quantity A[O], defined as the excess oxygen beyond what would be in equilibrium with carbon then present if the pressure of carbon monoxide were I atm.; that is, if [C] X [O] is taken as 0.00222, A[O] = [O] - 0.0022[C] where [O] is the percentage of oxygen by weight as measured by the method described earlier.3 This quantity ?[O] proves to be substantially independent of carbon content over the range 0.08 to I,z per cent, as well as of the basicity of the slag, and is nearly always within the limits o.o15 to o.oz5 per cent when the bath is boiling normally and is in what we have termed a steady state, Apparently it must be at least about 0.014 per cent before boiling occurs; but this threshold value seems to depend upon the ease of bubble formation at the metal-hearth interface, hence upon the condition of the surface of the hearth. In any case, ~(01, on the average, changes considerably following any disturbance of the bath, as by addition of ore. The present paper deals with the average changes in A[O] level following addition of spiegel or crop ends, or after procedures to promote stirring, or by tapping of the steel from the furnace. The observations were made on a large number of commercial heats, and consequently are subject to the influence of various disturbing factors; the results have the compensating merit of showing the consistency obtainable under the limitations imposed by practical operation. Variability of Excess Oxygen in Normal Open-hearth Operation The preceding genera' statements refer to the average value of A[0] particularly in heats that are boiling actively; on individual heats, which are less active, there may be a variable time lag between the disturbance and its effect, which complicates the interpretation of what is going on. For instance, if in the normal refining process boiling is sluggish, the slag usually is gaining Oxygen from the gas phase above it, Or from added Ore$ faster than it is losing oxygen to the metal; Yet when the bath starts to boil vigorously, the opposite condition may prevail for Some time. The consequence of this lag is a variation of A[o], the interpretation of which in a sing1e heat may not be immediately obvious. This condition is illustrated in Figs. I and 2. In Fig. 1, A[0] at the beginning of the test period was near the lower limit of its usual range (dashed lines) in the steady state as a consequence of the lime boil, which had ended about as indicated. The bath is now cold, carbon drop is slow, and the first small orc feed causes only a small rise in A[O]; as the temperature rises and as lime dissolves in the slag, and the bath becomes more active, the

Jan 1, 1948

By B. M. Larsen, T. E. Brower

In two previous paperslJ dealing with the carbon-oxygcn reaction, and the simultaneous content of each, in liquid steel in the furnace, we have made use of the quantity A[O], defined as the excess oxygen beyond what would be in equilibrium with carbon then present if the pressure of carbon monoxide were I atm.; that is, if [C] X [O] is taken as 0.00222, A[O] = [O] - 0.0022[C] where [O] is the percentage of oxygen by weight as measured by the method described earlier.3 This quantity ?[O] proves to be substantially independent of carbon content over the range 0.08 to I,z per cent, as well as of the basicity of the slag, and is nearly always within the limits o.o15 to o.oz5 per cent when the bath is boiling normally and is in what we have termed a steady state, Apparently it must be at least about 0.014 per cent before boiling occurs; but this threshold value seems to depend upon the ease of bubble formation at the metal-hearth interface, hence upon the condition of the surface of the hearth. In any case, ~(01, on the average, changes considerably following any disturbance of the bath, as by addition of ore. The present paper deals with the average changes in A[O] level following addition of spiegel or crop ends, or after procedures to promote stirring, or by tapping of the steel from the furnace. The observations were made on a large number of commercial heats, and consequently are subject to the influence of various disturbing factors; the results have the compensating merit of showing the consistency obtainable under the limitations imposed by practical operation. Variability of Excess Oxygen in Normal Open-hearth Operation The preceding genera' statements refer to the average value of A[0] particularly in heats that are boiling actively; on individual heats, which are less active, there may be a variable time lag between the disturbance and its effect, which complicates the interpretation of what is going on. For instance, if in the normal refining process boiling is sluggish, the slag usually is gaining Oxygen from the gas phase above it, Or from added Ore$ faster than it is losing oxygen to the metal; Yet when the bath starts to boil vigorously, the opposite condition may prevail for Some time. The consequence of this lag is a variation of A[o], the interpretation of which in a sing1e heat may not be immediately obvious. This condition is illustrated in Figs. I and 2. In Fig. 1, A[0] at the beginning of the test period was near the lower limit of its usual range (dashed lines) in the steady state as a consequence of the lime boil, which had ended about as indicated. The bath is now cold, carbon drop is slow, and the first small orc feed causes only a small rise in A[O]; as the temperature rises and as lime dissolves in the slag, and the bath becomes more active, the

Jan 1, 1948

By W. R. Ingalls

ThE following chronology presents the history of lead-mining in the United States in a brief form and is a useful reference in connection with the statistics of production: 1621.. Lead was mined and smelted near Falling Creek, Va., to supply the local demand for bullets and shot. This was the first mining and .smelting of lead in what is now the United States. 1632. In a report made on the minerals of New England, lead-ore is mentioned. (Bishop, I., 470.) 1650. Supposed beginning of mining by Jesuits in Pima county, Ariz. 1651. Grant of lead-mine at Middletown, Conn., to Gov. John Winthrop. 1682. Lead-ore supposed to have been discovered in Wisconsin by Nicholas Perrot. (K. D. Irving, Mineral Resources of Wisconsin, Trans., viii., 498.) 1700 Discovery of lead in Missouri by Penicaut, one of Le Sueur's party. Tile same expedition discovered lead near the southern boundary of Wisconsin in August of the same year. 1712. Grant by Louis XIV. of the Crozat patents, with special privileges respecting the discovery and operation of mines in the then territory of Louisiana. Little or no mining was done under this patent until about 1720. 1717. Transfer of Crozat patents to the Mississippi Co., promoted by John Law, which prepared for active mining. 1719. First attempt to mine and smelt lead in Missouri, made by Sieur de Lochon, in behalf of the Mississippi Co., near Meramec river. Results unsuccessful.

Jan 1, 1908

By M. Gell, G. R. Leveran

The high- and low-cycle fatigue properties of the nickel-base superalloy, Mar-MBOO, in columnar-grained and single-crystal forms were determined at room temperature. It was found that the fatigue lives of these materials were greatly affected by the size of preexisting cracks in MC-type carbides contained in the micro structure. Most of the data falls on two curves given by: (zN)'/A€= K, where Nf is the number of cycles to failure, Af is the total strain range, and K is a function of carbide size. No difference was observed in the fatigue behavior of the columnar-grained and single-crystal materials for the same MC carbide size. Matrix slip and crack initiation occurred at precracked MC carbides and, to a lesser extent, at micropores. Fatigue crack propagation was mainly in the Stage I mode, i.e., on cry stallo graPhic slip planes. The Stage I fracture in these materials was unusual in that distinct features were observed on the fracture surfaces. In high-cycle fatigue, these features resembled those commonly observed on the cleavage fracture surfaces of bcc and hcp materials. Yet, in this study, the cracks propagated slowly in a cyclic manner. In low-cycle fatigue, the Stage I facets contained equiaxed dimples, similar to those observed on the tensile fracture surfaces of ductile materials. These observations indicate that both local normal and shear stresses are involved in these Stage I fractures. A model is proposed to explain these results based on the weakening of the cohesive energy of the active slip planes by reversed shear deformation and the fracture of the bonds across the weakened planes by the local normal stress. RECENT developments in casting technology have produced cast nickel-base superalloys in columnar -grained and single-crystal forms.1'2 The tensile and creep properties of the nickel-base superalloy, Mar-M200, cast in these forms have been shown to be superior to the corresponding properties of the conventionally cast polycrystalline material.lp2 This improvement in properties results, in part, from the elimination of grain boundaries in the single crystals and the alignment of the grain boundaries parallel to the stress axis in the columnar-grained castings. As part of a program to evaluate the fatigue properties of nickel-base superalloys cast in single-crystal and columnar-grained forms, a study has been made of the cyclic deformation and fracture of Mar-M2OO at room temperature. M. fiFl I .hininr Mpmher AIMF ic ^pninr Rocoarrh Accn^iata anH I) EXPERIMENTAL PROCEDURE The composition range of Mar-Ma00 in weight percent is: 8 to 10 Cr, 9 to 11 Co, 11.5 to 13.5 W, 0.75 to 1.25 Cb, 1.75 to 2.25 Ti, 4.75 to 5.25 Al, 0.01 to 0.02 B, 0.03 to 0.08 Zr, 0.07 to 0.12 C, bal. Ni. All of the castings met the above specifications. The castings were solutionized for 1 to 4 hr at 2250°F followed by aging at 1600°F for 32 hr which resulted in a 0.2 pct offset yield stress of 150,000 psi at room temperature. The microstructure of the material consisted of cuboidal, coherent particles of ordered, fcc Ni3(A1,Ti) (commonly designated y'), approximately 0.3 p on edge, distributed in an fcc y solid-solution matrix. MC carbides together with shrinkage and gas micropores were also distributed throughout the materials. The MC carbides and micropores were located preferentially in the interdendritic interstices, as well as in the grain boundaries in the columnar-grained castings. The (100) direction of all the single crystals and the common (100) axis of the grains in the columnar materials were aligned within about 5 deg of the specimen axis. Fatigue testing was carried out in the high-cycle (HCF) and low-cycle (LCF) fatigue regions, with the major difference being gross yielding of the specimen occurred during the first cycle in the LCF region. This division also corresponded with the more usual one in which the life of a specimen in LCF is less than lo4 cycles and that in HCF is greater than lo4 cycles. The designs of the high-cycle fatigue and low-cycle fatigue specimens are shown in Figs. l(a) and (c), respectively. The gage sections of both HCF and LCF specimens were electropolished prior to testing. The HCF specimens were tested in an MTS, closed-loop, hydraulic fatigue machine at 10 cps in air. The specimens were cycled between a tensile stress of 5000 psi and a maximum tensile stress which ranged from 35,000 to 125,000 psi, Fig. l(b). The LCF specimens were cycled under strain control from zero to a maximum tensile strain, Fig. l(d), in a Wiedemann-Baldwin testing machine. The experimental procedure has been described elsewhere.3'4 Both HCF and LCF tests were interrupted periodically in order to replicate the development of slip and cracking at the specimen surface. This was accomplished by placing plastic replicating tape around the gage section of the specimen while the specimen was in the mahine. The size of the MC carbides for all specimens was measured on a polished longitudinal section through the gage section after fatigue testing. The method of measurement consisted of carefully scanning the entire polished section in order to locate the largest MC carbides. Photographs were then taken of the six longest carbides oriented approximately normal to the

Jan 1, 1969

By James W. Halley

"Fine-grained" steels have been standard products for many years. This paper describes an investigation of the effects of some of the more common grain-growth inhibitors used to produce these steels. The properties, response to heat-treatment, and the deoxidation practice necessary to produce "fine-grained" steels have been the subjects of numerous papers. It has been shown that a substantial quantity of aluminum is necessary to produce this type of steel, and it has been indicated that titanium and zirconium produce a similar result. For some time there was a lively argument between those who felt that aluminum refined the grain and those who felt that aluminum oxide was the effective agent. This argument subsided with an apparent victory for those promoting aluminum oxide. Most of the work on grain size has divided steels into two broad classifications based upon McQuaid and Ehn's original carburizing test at 1700°F or some similar test at this temperature. If the steel coarsened at this temperature, it was coarse grained, while if it did not it was he grained. Quantitative data concerning how much a certain amount of aluminum raised the coarsening temperature and affected the properties, all other factors being constant, are very meager. Similar information regarding titanium and zirconium is practically nonexistent. The published information on aluminum yields some quantitative information. Epstein, Nead and Washburn' gave the first quantitative information on the amount of aluminum necessary to prevent grain growth at 1700°F. They showed that the addition of a pound to a pound and a half of aluminum per ton (0.05 to 0.075 per cent) would assure steel that would not coarsen during a McQuaid-Ehn test at 1700°F. Herty, McBride and Houghg reported that a steel containing 0.020 per cent acid-soluble aluminum coarsened between 1742° and 1832°F., while steels containing 0.016 per cent and 0.017 per cent acid-soluble aluminum coarsened between 1652° and 1742°F. compared with similar aluminum-free steels that started to coarsen at 1580°F. Herty3 also showed a marked improvebent in low-temperature notched impact resistance with increasing acid-soluble aluminum up to 0.030 per cent. McQuaid4 compared the coarsening of steels containing 0.011 to 0.204 per cent total aluminum and found a maximum coarsening temperature at 0.098 per cent aluminum. He had no samples between 0.015 and 0.098 per cent aluminum. Houdrement6 found a marked decrease in coarsening temperature with aluminum contents above 0.50 per cent. Kinzel, Crafts and Egan6 found that aluminum and zirconium improved the low-temperature impact resistance of a low-alloy steel, while titanium was detrimental. Sims7 shows that sulphur increases the coarsening temperature and that the maximum coarsening temperature is between 0.04 and 0.06 per cent added aluminum. The fact that the coarsening temperature passes through a maximum with increasing aluminum content appears to be well established. The aluminum content that

Jan 1, 1947

By James W. Halley

"Fine-grained" steels have been standard products for many years. This paper describes an investigation of the effects of some of the more common grain-growth inhibitors used to produce these steels. The properties, response to heat-treatment, and the deoxidation practice necessary to produce "fine-grained" steels have been the subjects of numerous papers. It has been shown that a substantial quantity of aluminum is necessary to produce this type of steel, and it has been indicated that titanium and zirconium produce a similar result. For some time there was a lively argument between those who felt that aluminum refined the grain and those who felt that aluminum oxide was the effective agent. This argument subsided with an apparent victory for those promoting aluminum oxide. Most of the work on grain size has divided steels into two broad classifications based upon McQuaid and Ehn's original carburizing test at 1700°F or some similar test at this temperature. If the steel coarsened at this temperature, it was coarse grained, while if it did not it was he grained. Quantitative data concerning how much a certain amount of aluminum raised the coarsening temperature and affected the properties, all other factors being constant, are very meager. Similar information regarding titanium and zirconium is practically nonexistent. The published information on aluminum yields some quantitative information. Epstein, Nead and Washburn' gave the first quantitative information on the amount of aluminum necessary to prevent grain growth at 1700°F. They showed that the addition of a pound to a pound and a half of aluminum per ton (0.05 to 0.075 per cent) would assure steel that would not coarsen during a McQuaid-Ehn test at 1700°F. Herty, McBride and Houghg reported that a steel containing 0.020 per cent acid-soluble aluminum coarsened between 1742° and 1832°F., while steels containing 0.016 per cent and 0.017 per cent acid-soluble aluminum coarsened between 1652° and 1742°F. compared with similar aluminum-free steels that started to coarsen at 1580°F. Herty3 also showed a marked improvebent in low-temperature notched impact resistance with increasing acid-soluble aluminum up to 0.030 per cent. McQuaid4 compared the coarsening of steels containing 0.011 to 0.204 per cent total aluminum and found a maximum coarsening temperature at 0.098 per cent aluminum. He had no samples between 0.015 and 0.098 per cent aluminum. Houdrement6 found a marked decrease in coarsening temperature with aluminum contents above 0.50 per cent. Kinzel, Crafts and Egan6 found that aluminum and zirconium improved the low-temperature impact resistance of a low-alloy steel, while titanium was detrimental. Sims7 shows that sulphur increases the coarsening temperature and that the maximum coarsening temperature is between 0.04 and 0.06 per cent added aluminum. The fact that the coarsening temperature passes through a maximum with increasing aluminum content appears to be well established. The aluminum content that

Jan 1, 1947

By F. W. McQuiston

INTRODUCTION IDARADO Mining Company's mill and surface plant are at the portal of the Treasury tunnel at elevation 10,625 ft, 12 miles south of Ouray, Colo. In 1943 and 1944 this tunnel was extended in a westerly direction to tap the Black Bear vein, and, together with the recently completed 1100-ft inclined Treasury raise, provides access to the Black Bear mine. In 1945 a 250-ton mill was placed in operation to process development ores containing much needed copper, lead and zinc for war requirements, and to serve as a pilot testing unit for larger scale milling operations. In the years 1902 to 1927 some 329,000 tons of ore were produced from mine workings on the Black Bear vein that extended downward from elevation 12,325 ft at the Black Bear tunnel portal to elevation 11,618 ft, the lowest level of the mine. The ores were taken to the Cascade and Smuggler-Union mills near Telluride over two aerial tramways. Gold bullion, a copper-lead concentrate, and a zinc concentrate were produced. ORES The Black Bear is a compound fissure vein that has undergone several stages of mineralization. The first important stage is represented by complex ores of copper, lead and zinc in a quartz gangue. Precious metal content in this stage is low. The galena is argentiferous and varying amounts of tetrahedrite, freibergite and bornite tend to increase the normal copper content represented in chalcopyrite. The zinc occurs as a true sphalerite with little or no iron. Later re-openings of the fissure took place more or less co-extensively with the successive introduction of (1) abundant quartz gangue containing minor amounts of chalcopyrite, galena and sphalerite; (2) free gold in a fluoritic quartz gangue; and (3) barren, low-grade quartz with minor amounts of pyrite as the only important sulphide. The sulphides show practically no oxidation and little mineralogic intergrowth. Because of the common overlapping of these successive stages of mineralization within a given mining area, considerable dilution of the base-metal content takes place, thus lowering the average mill-head grade. PLANT PRACTICE Metallurgical testing was started shortly after the Black Bear vein was encountered on Treasury tunnel level in 1944. Laboratory tests showed good flotability of the minerals in the ore and indicated an economic separation could be made of the copper, lead and zinc minerals into their respective concentrates. The success of the separation is close reagent control to maintain a balance between promotion and depression of the sulphides. To maintain this balance reagent consumption for the three metal separation is considerably higher than in ordinary lead-zinc flotation.

Jan 1, 1947

By Charles Will Wright

DESPITE the war, the First Pan American Mining Congress, held in Santiago, Chile, Jan. 15-23, was attended by about 300 persons including the official delegates from sixteen of the American republics. The United States delegation consisted of Elmer Pehrson, of the U. S. Bureau of Mines; D. F. Hewett, of the U. S. Geological Survey; William H. Hobbs, of the Carnegie Foundation; and C. W. Wright, delegate of the Board of Economic Warfare and of the A.I.M.E. Mr. Wright was elected to head the delegation. Among the other members were Edward Steidle, of Pennsylvania State College and also an official A.I.M.E. delegate; John Huttl, of Engineering and Mining Journal; W. 0. Vanderburg, foreign mineral specialist from Lima, Peru; O. B. Hundley, of the American Cyanamid Co.; Horace Graham, of the Anglo-Chilean Nitrate Co.; and several officials and engineers from the Anaconda, Kennecott, and Bethlehem Steel companies' mines in Chile.

Jan 1, 1942

Extractive Metallurgy Division Institute of Metals Division Iron and Steel Division Council R R McNaughton, Chairman (EMD), Ernest O Kirkendall, Secretary, J H Scaff, (IMD), Morris Cohen, (IMD), T J McLoughlin, (ISD), J S Marsh, (ISD), P T Stroup, (EMD), R D Parks, (MED), D S Eppelsheimer, (MIED) Journal of Metals Editorial Advisory Committee J S Smart, Jr, Chairman, W A Dean, T D Jones, Evan Just, J C Kinnear, Jr, J S Marsh, M Tenenbaum Pacific Northwest Regional Meeting F X Cappa, General Chairman, W W Wiltschko, Chairman (Metals Branch), Program Chairmen H E Lee (EMD), S E Maddigan (IMD), G R Heffernan (ISD), L C Richards (Ind Min Div), James Bell (Finance Committee), Ed Vestica (Registration), Donald Johnson (Special Events)

Jan 1, 1954

By AIME AIME

THE technical material in hand and the plans under way for the 141st meeting of the Institute clearly indicate a well-rounded program of unusual excellence. The meeting will be held in the Engineering Societies Building, Feb. 15 to 18, and while it is too early to announce definitely the time of the various sessions much of the detail has been organized up to that point. Every group in the Institute membership will find much of special interest, and several features should prove generally attractive. The various committees in charge of the lighter side of the meeting are hard at work to emulate the standard established last February In this connection and in this paragraph it will suffice to say-there will be a Smoker-dinner! The Committee on Mining Methods plans two sessions for which these papers are in prospect:

Jan 1, 1932

By J. F. Enrietto

Internal friction measurements were used to determine the effect of manganese on the solubility and precipitation kinetics of nitrogen. Manganese, in concentrations up to 0.75 pct, has little effect on the solubility at temperatures above 250°C. On the other hand, at Concentrations as low as 0.15 pct, manganese inhibits the formation of iron nitrides, especially Fe4N, even though it may not form a precipitnte itself. The precipitation and solubility of carbides and nitrides have been extensively investigated in the pure Fe-C and Fe-N systems.1-3 In recent years, some effort has been ispent in studying the influence of substitutional alloying elements on the behavior of carbon and nitrogen in ferrite.4 -7 In particular Fast, Dijkstra, and Sladek have investigated the effect of 0.5 pct Mn on the internal friction and hardness during the quench aging of Fe-Mn-N alloys.', ' They found that at low temperatures (below 200°C) the presence of 0.5 pct Mn greatly retarded quench aging. For example, after 66 hr at 200°C very little precipitation had taken place in the iron alloyed with manganese, whereas precipitation was complete after a few minutes in a pure Fe-N alloy. The effect of varying the manganese content and the details of the precipitation process were not mentioned in these papers. Fast' postulated that manganese causes a local lowering of the free energy of the lattice with a resulting segregation of nitrogen atoms to these low energy sites. The segregated nitrogen atoms are bound so tightly to the manganese atoms that they cannot form a precipitate. The internal friction measurements of Dijkstra and Sladek tended to confirm the concept of segregation of nitrogen around manganese atoms, and the increase in free energy on transferring a mole of nitrogen atoms from a segregated to a "normal" lattice site was computed to be - 2800 cal. Dijkstra and Sladek9 distinguished between two types of precipitates: ortho, a nitride of appreciably different manganese content than that of the matrix, and para, a nitride with a manganese content essentially that of the matrix. With each type of precipitate a solubility, again designated ortho or para, can be associated. Since the internal friction maximum in alloys which were aged several hours at 600" C dropped almost to zero, Dijkstra and Sladek9 concluded that the ortho solubility must be very low. The effect of temperature on the ortho and para solubilities has no1: been investigated. There are obviously several gaps in our knowledge concerning the influence of manganese on the behavior of nitrogen in a-iron. It was the purpose of the experiments described in this paper to determine the following: 1) The ortho and para solubilities of nitrogen as a function of temperature. 2) The details of the precipitation process at elevated temperatures. 3) The effect of varying the manganese concentration on the above phenomena. EXPERIMENTAL PROCEDURE Internal friction is conveniently employed in studying the precipitation of nitrides and/or carbides from a -iron because it is one of the few parameters, perhaps the only one, which is not affected by the presence of the precipitate itself. For this reason, internal friction techniques were heavily relied upon in the present experiment. A) Preparat of -. All specimens were prepared from electrolytic iron and electrolytic manganese. Alloys containing 0.15, 0.33, 0.65, and 0.75 wt pct Mn were vacuum melted and cast into 25 lb ingots. After being hot rolled to 3/4 in. bars, the ingots were swaged and drawn to 0.030 in. wires. The wires wen? decarburized and denitrided by annealing at 750° C for 17 hr in flowing hydrogen saturated with warer vapor. To obtain a medium grain size, - 0.1 mm, the wires were then heated to 945oC, allowed to soak for 1 hr, furnace cooled to 750°C, and water quenched. Subsequent internal friction measurements showed that this procedure reduced the nitrogen and carbon concentrations of the alloys to less than 0.001 wt pct. The wires were nitrided by sealing them in pyrex capsules containing anhydrous ammonia and annealing them for 24 hr at 580°C, the nitrogen being retained in solid solution by quenching the capsule into water. Immediately after quenching, the wires were stored in liquid nitrogen to prevent any precipitation of nitrides. By varying the pressure of ammonia in the capsule, it was possible to produce any desired nitrogen concentration. B) Internal Friction. The internal Friction measurements were made on a torsional pendulum of the Ke type,'' a frequency OF 1. or 2 cps being used. For

Jan 1, 1962

By James W. Halley

' FINE-GRAINED " steels have been standard products for many years. This paper describes an investigation of the effects of some of the more common grain-growth; inhibitors used to produce these steels. The properties, response to heat-treatment, and the deoxidation practice necessary to produce "fine-grained" steels have been the subjects of numerous papers. It has been shown that a substantial quantity of' aluminum is necessary to produce this type of steel, and it has been indicated that titanium and zirconium produce a similar result. For some time there was a lively argument between those who felt that aluminum refined the grain and those who felt that aluminum oxide was the effective agent. This argument subsided with an apparent victory for those promoting aluminum oxide. Most of the work on grain size has divided steels into two broad classifications based upon McQuaid and Ehn's original carburizing test at 1700°F. or some similar test at this temperature. If the steel coarsened at this temperature, it was coarse grained, while if it did not it was fine grained. Quantitative data concerning how much a certain amount of aluminum raised the coarsening temperature and affected the properties, all other factors being constant, are very meager. Similar information regarding titanium and zirconium is practically nonexistent. The published information on aluminum yields some quantitative information. Epstein, Nead and Washburn' gave the first quantitative information on the amount of aluminum necessary to prevent grain growth at 1700°F. They showed that the addition of a pound to a pound and a half of aluminum per ton (0.05 to 0.075 per cent) would assure steel that would not .coarsen during a McQuaid-Ehn test at 1700°F. Herty, McBride and Hough2 reported that a steel containing 0.020 per cent acid-soluble aluminum coarsened between 1742° and 1832°F., while steels containing 0.016 per cent and 0.017 per cent acid-soluble aluminum coarsened between 1652~ and 1742°F. compared with similar aluminum-free steels that started to coarsen at 1580°F. Herty3 also showed a marked improvement in low-temperature notched impact resistance with increasing acid-soluble aluminum up to 0.030 per cent. McQuaid4 compared the coarsening of steels containing 0.011 to 0.204 per cent total aluminum and found a maximum coarsening temperature at 0.098 per cent aluminum. He had no samples between 0.015 and 0.098 per cent aluminum. Houdrement5 found a marked decrease in coarsening temperature with aluminum contents above 0.50 per cent. Kinzel, Crafts and Egan6 found that aluminum and zirconium improved thy low-temperature impact resistance of a low-alloy steel, while titanium was detrimental. Sims7 shows that sulphur increases the coarsening temperature and that the maximum coarsening temperature is between 0.04and 0.06 Per cent added aluminum. The

Jan 1, 1946