Search Documents

By J. A. Lund, A. M. Lawson

THE structures of quenched eutectoid and hypereu-tectoid Fe-Cu alloys have been examined by X-ray diffraction and by optical and electron microscopy. The relevant portion of the Fe-Cu phase diagram is given in Fig. 1. Several values have been reported for the solubility of copper in a Fe at the eutectoid temperature, including 1.4 wt pct by orton' and 2.13 wt pct by Wreidt and Darken.2 Alloys containing 4.8 and 7.5 wt pct Cu have been prepared from two batches of Ferrovac E iron (0.005C and 0.013C) and electrolytic tough pitch copper (99.90 Cu). Specimens of dimensions 0.8 by 0.8 by 0.1 in. were cut from hot-rolled material, austenitized, and quenched into brine at 25°C. Similar specimens were also cooled in the furnace, after a short soaking treatment at 1100°C, at a rate estimated to be 10°C per min in the temperature range of 900" to 500°C. X-ray diffractometry was performed on quenched and on furnace-cooled bulk specimens using iron radiation. Only a bcc phase could be detected in all samples. Lattice parameters were calculated from measurements on four lines, made up of two resolved high-angle doublets. Comparisons were made against a silicon standard. Results are shown in Table I. Based on X-ray diffraction studies of a series of alloys of lower copper concentrations, orton' estimated that the tattice constant of a Fe at 25°C increases 0.0014A per wt pct Cu in solution. Extrapolating Norton's data, it may be concluded that all copper was retained in solution in the brine-quenched 4.8 pct Cu alloy, and that approximately 5 pct Cu was also held in solution on quenching the 7.5 pct Cu alloy. Typical microstructures of brine-quenched specimens, as observed by optical microscopy, are shown in Figs. 2 and 3. Precipitation of the E phase (copper-rich) occurred along the y grain boundaries on quenching the 7.5 pct Cu alloy, rendering them readily detectable in the microstructure, Fig. 3. The original boundaries in the 4.8 pct Cu specimens were gener- ally not discernible, however. This indicates that the z phase which was seen in the higher-copper alloy was probably of proeutectoid origin. Thin foils for transmission electron microscopy were obtained from bulk specimens by spark machining to 0.006 in. thickness, followed by electrolytic polishing. Typical transmission electron micrographs

Jan 1, 1967

By George Hulst

PRIOR to 1914, there was little demand for antimony in this country; its use was limited almost entirely to the manufacture of type and bearing metals. Practically no antimony ore was mined here, the market being supplied principally from China, and the alloy was produced by a direct mixing of lead and antimony. The great world war, with its demand for shrapnel in hitherto undreamed of quantities, precipitated a great boom in the price of antimony. Nominally quoted at 6 c. to 7 c. in 1914, the price increased by leaps and bounds to 45 c. in March, 1916. Under the stimulus of high prices many shall mines were opened, for it became profitable to work ores containing as low as 20 percent. antimony. High-grade sulfide ores (stibnite), containing 55 per cent. to 60 per cent. antimony, were received from Bolivia, China, and Alaska. Low-grade sulfide ores, running from 20 per cent. to 45 per cent., were produced in Nevada, California, Idaho, Utah, and Mexico; much of this ore was fairly rich in silver. The principal oxide ores came from Mexico and Oregon. The following analyses are representative of various types of antimony ore: Se Pn Cu Ao Au SIC), Fe S CAO ZN As Oxide Ore 25.09 46.02 0.95 0.40 10.98 0.30 0.22 Sulfide ore 5.5.20. 15.12 1.05 19.87 ? 0.40 0.25 Sulfide Ore 37.16 11.30 0.10 34.0 7.60 0.50 17.05 7.40 0.36 0.10 Sulfide Ore 41.55 15.00 0.20 76.0 0.04 5.60 0.25 18.17 0.85 0.25 0.10 The International Lead Refining Co. fortunately was equipped to handle these ores through residue and blast furnaces. The charge consisted of a variety of sulfide ores containing Sb 20 to 60 per cent. and Si02 6 to 45 per cent., oxide ores containing Sb 20 to 40 per cent. and SiO2 10 to 45 per cent. Secondary materials, such as battery plates, battery mud, lead oxide, paint, etc., together with refinery skims, softener skims, and other refinery byproducts, were treated along with the antimony ore to furnish the lead required. All silver-bearing antimony ores were treated in the residue furnace, the sulfur, iron, and copper forming matte that carried part of the silver, the balance going into lead bullion. The

Jan 9, 1919

By George P. Hulst

Prior to 1914, there was little demand for antimony in this country; its use was limited almost entirely to the manufacture of type and bearing metals. Practically no antimony ore was mined here, the market being supplied principally from China, and the alloy was produced by a direct mixing of lead and antimony. The great world war, with its demand for shrapnel in hitherto undreamed of quantities, precipitated a great boom in the price of antimony. Nominally quoted at 6 c. to 7 c. in 1914, the price increased by leaps and bounds to 45 c. in March, 1916. Under the stimulus of high prices many small mines were opened, for it became profitable to work ores containing as low as 20 per cent. antimony. High-grade sulfide ores (stibnite), containing 55 per cent. to 60 per cent. antimony, were received from Bolivia, China, and Alaska. Low-grade sulfide ores, running from 20 per cent. to 45 per cent., were produced in Nevada, California, Idaho, Utah, and Mexico; much of this ore was fairly rich in silver. The principal oxide ores came from Mexico and Oregon. The following analyses are representative of various types of antimony ore: Sb Pb Cu AG AU SIO2 Be S CaO Zn As Oxide ore.......... 25.09 46.02 0.95 0.40 10.98 0.30 0.22 Sulfide ore......... 55.20 15.12 1.05 19.87 0.40 0.25 Sulfide ore......... 37.16 11.30 0.10 34.0 7.60 0.50 17.05 7.40 0.36 0.10 Sulfide ore......... 41.55 18.00 0.20 76.0 0.04 5.60 0.25 18.17 0.85 0.25 0.10 The International Lead Refining Co. fortunately was equipped to handle these ores through residue and blast furnaces. The charge consisted of a variety of sulfide ores containing Sb 20 to 60 per cent. and SiO2 6 to 45 per cent., oxide ores containing Sb 20 to 40 per cent. and SiO2 10 to 45 per cent. Secondary materials, such as battery plates, battery mud, lead oxide, paint, etc., together with refinery skims, softener skims, and other refinery byproducts, were treated along with the antimony ore to furnish the lead required. All silver-bearing antimony ores were treated in the residue furnace, the sulfur, iron, and copper forming matte that carried part of the silver, the balance going into lead bullion. The antimony slag produced was sufficiently low in silver to warrant being smelted in the blast furnace to antimonial lead.

Jan 1, 1921

By William P. Shinn

IT seems proper to present in the Transactions of the Institute, from time to time, formal record of the advances made in the arts and sciences to which our organization is devoted-milestones in the highway of progress-from which our successors may measure what they in their turn have gained. The admirable address of the Hon. Abram S. Hewitt, then president elect of the Institute, on "A Century of Mining and Metallurgy in the United States," read at the opening of the meeting held in this hall in June, 1876, forms a point of departure, and the conclusion of the eighth decade of the nineteenth century and the end of the first five years of our country's second century seem to offer a fitting time for again making up our record. The period since 1875 has been marked by a degree of activity in mining and metallurgical industry never before equalled in our history, while the progress made in the science and art has been, if possible, still more noticeable. Whether we consider the mining of iron, ore, and coal, or of the precious metals,-the advances made in smelting the former and in reducing the latter, the extraordinary increase in the production of Bessemer steel, or the science of Thomas and. Gilchrist, which makes the hitherto rejected phosphorus the corner-stone of success,-the past five years are alike memorable for the progress they have shown and to some of the most marked features of this progress I will now oriefly call your attention. It may be of interest in this connection to note the following figures, showing the growth of the population of the United-States during the last three decades :

Jan 1, 1881

By Benjamin LeRoy Miller, Joseph T. Singewald

For a number of years Russia, India and Brazil have outranked all other countries as producers of manganese ores. During the 5 years immediately preceding the European war, the average annual production of Russia was 844,000, of India 694,000 and of Brazil 200,000 long tons. Since the outbreak of the war there has been a considerable falling off in the Russian and Indian production, particularly in the former, whereas the production of Brazilian ores has been greatly increased, amounting in 1914 to over 250,000 tons and in 1915 to nearly 350,000, with conditions favorable for a still larger production in 1916. Manganese is one of the few industrially important metals that are not produced in the United States in quantity commensurate with our needs, so that we have been compelled to import annually about 300,000 tons, having a value of over $2,000,000, and these ores have been obtained from the three countries mentioned above. Their rank as contributors to our imports of manganese ores was India, Russia, Brazil; and in 1913, Brazil contributed only one-fifth. During the past 2 years Brazil has furnished rapidly increasing quantities to this country, and, with the falling off of imports from India and Russia, has become our principal foreign source. In 1914, Brazil furnished two-fifths of the imports and more than India or Russia, and in 1915 over nine-tenths. The manganese ores of Brazil are consequently of more than usual interest to us at this time. The Manganese-Ore Distbicts of Brazil , The manganese mining industry of Brazil dates from the year 1894, and since that year the total production has been over 3,000,000 tons. With the exception of a small quantity produced in the State of Bahia from deposits west of the City of Bahia, this output has come from the

Jan 1, 1917

By A. H. Bell

DEEPEST hole in the earth, and deepest producing oil well in the world-such is well No. K.C.L. A-2, of the Continental. Oil Co., completed on April 12 in the San Joaquin valley about four miles west of Wasco, Calif. It penetrated the earth's crust to a depth of 15,004 ft.- almost three miles-a depth that exceeds by over 2200 ft. that of the previous record holder in western Texas. It is now producing oil from sands at a depth from 13,092 to 13,- 175 ft., which is about 1500 ft. deeper than the record formerly achieved in Louisiana. Continental's new well was bottomed in what is possibly Domengine-Avenal Eocene sand, and is producing from the Middle Miocene equivalent to the Rio Bravo sand.

Jan 1, 1938

By R. H. Richman, F. Borik

A 0.3 pct C-12 pct Cr-6 pct Ni steel was rolled to 93 pct reduclion in area as austenite at 510°C, and then partially transformed as desired to ~rlartensite by qnenching to - 196°C. Pole figures for the austenitic matrix and for the martensitic product were separately determined by an X-ray transmission method. The deforitration texture of' the warm-worked austenite is characlerized by (110)(225) components, and is thus closely similar to those produced in a brasses. The pole jigure of the martensite in partially transformed material agrees well with that which can be constructed by transfortnation of the {110)(225) orientations according to either the Kuvdjuniov- Sacks or the Nishi-yatuu relatiotship. Howeuer, an important result of this construction is that me-third of the predicted orientations are missing. A graphical analysis can then be used to show that in deformed austenite certain crystallographic variants of martensite (related to the most probable austenite slip systems) are suppressed, resulting in this preferred transformation. The evidence for preferred transformation is corroborated by the measured elastic anisotropy of warm-rolled and fully transformed H-11 steel. EXTENSIVE plastic deformation of a polycrystal-line aggregate in a manner that causes flow predominantly in one direction results in a preferred orientation of the constituent crystallites. The particular orientations that are produced depend upon the crystal structure and composition of the material, as well as upon the temperature, mode, and degree of deformation; in any case, the preferred crystallo-graphic orientations, or textures, are reflected in directionality of mechanical properties. Although such anisotropy may be exploited in certain specialized applications, it is more commonly diminished or eliminated by heat treatment lest it interfere undesirably in subsequent forming operations or in structural design. In the recently developed thermomechanical treatments that significantly enhance the strength of some steels,1,2 considerable deformation of the metastable austenite prior to the martensite transformation is essential to the strengthening process. If the austenite is textured by the deformation, and if the transformation to martensite proceeds according to one of the relationships established for transformation in annealed austenite, then it must be expected that the martensite will also possess a preferred orientation even though the multiplicity of martensite orientations possible in a given austen- ite crystal will tend to restore some degree of randomness. The existence of a residual anisotropy, both mechanical 3-6 and crystallographic,' has been substantiated. In the latter crystallographic investigation, preferred orientations were determined for the martensitic structure of an SAE 4340 steel rolled 72 pct as austenite at 833°C and then quenched. However, the choice of a composition that transformed almost completely to martensite during the quench to room temperature did not permit direct measurement of the prior austenitic texture. In fact, when the "ideal orientations'' associated with well-known fcc rolling textures were converted, alone or in combination, to martensite according to the Kur-djumov-Sachs (K-s)' or Nishiyama8 relations, the agreement obtained with the observed martensite texture was only fair at best. Recently a pertinent aspect of the austenite to martensite transformation was reported by Bokros and parker,10 who found that certain habit-plane variants of martensite were suppressed by tensile deformation of Fe-31.7 Ni single crystals prior to the necessary subzero cooling. It might be anticipated that the consequences of such preferred transformation are sustained during the formation of martensite in warm-worked austenite that has a well-developed deformation texture. The present investigation was undertaken first to establish more firmly the relation between preferred orientations in plastically deformed austenite and in the resulting martensite, and second to examine the textures for evidence of deformation-induced preferred transformation. EXPERIMENTAL PROCEDURES An alloy containing 0.3 pct C, 12 pct Cr, 6 pct Ni, and the balance iron, was selected because the mar-tensite-start temperature (M,) of about -100°C allowed convenient experimental manipulation of either austenite or martensite at room temperature. Furthermore, this composition can be readily deformed as metastable austenite at moderately elevated temperatures without intervention of appreciable isothermal or athermal decomposition products. The alloy was austenitized at 1150°C, aircooled to 510°C, rolled unidirectionally at this temperature to 93 pct reduction of cross-sectional area, and finally oil-quenched to room temperature. Partial transformation to martensite was accomplished by quenching to -196°C as needed. The rolled stock was reduced in thickness from 0.067 to 0.010 in. by etching in a solution of 5 pct HC1, 45 pct HNO3, and 50 pct water, and further thinned by careful mechanical polishing to maintain the two sides of the sheet parallel within 0.0003 in. After mechanical polishing to 0.005 in., electropolishing in 1:9 perchloric-acetic acid solution produced a final thickness of 0.002 in. The preferred orientations were determined from

Jan 1, 1968

By Arthur L. Christenson, Clarence E. Jackson

In the establishment of the relationship between weldability and hardenability, two methods have been employed in correcting for the grain growth produced in the heat-affected zone: first, the hardenability calculated from chemical composition* may be corrected to the grain size observed in an actual weld? or, second, a hardenability test may be made on the steel quenched from a temperature high enough to produce a grain size comparable to that found in the heat-affected zone.8 In order to obtain grain sizes in the end-quench hardenability bar comparable to those resulting in the base metal from the welding cycle, a quenching temperature of 2Ioo°F. has been used. In studies of the end-quench hardenability specimen quenched from 2Ioo°F. instead of from a lower temperature of I7OO°F., it is impor-TaiiT to ascertain The relative cooling rates for various distances along the bar. It is a question as to whether the cooling occurs at the same rate or whether there is any significant difference from the standard cooling-rate curve published by Jominy and confirmed by others.4,5 This paper reports experimental evidence concerning the effect of quenching temperature on the cooling rates in the end-quench hardenability test. The effect of quenching temperatures on cooling rates has been studied by a number of investigators.6'7 French has considered this effect from both theoretical and experimental aspects. In French's studies on complete quenching of spheres and rounds, an increase in the quenching temperature caused an increase in the cooling rate at 720°C. at the center of the specimen. The center cooling velocity also has been shown to be dependent upon the surface per unit volume for the type of specimens studied; the velocity of cooling increases with an increase in the surface per unit volume. Three methods of indicating the rapidity of cooling of a body of metal during a quenching operation have been propped: I. The time it takes for the metal to cool from the quenching temperature to a temperature halfway between the quenching temperature and the temperature of the quenching medium (half-temperature time): Grossmann, Asimow and Urban7 justify the use of this criterion by the fact that the half-temperature time includes the temperature and time of incubation as well as the zone of formation of pearlite and, further, the data so derived accord very closely with experimental values. 2. The time interval the metal remains in a given temperature range; for example,

Jan 1, 1944

By Arthur L. Christenson, Clarence E. Jackson

In the establishment of the relationship between weldability and hardenability, two methods have been employed in correcting for the grain growth produced in the heat-affected zone: first, the hardenability calculated from chemical composition* may be corrected to the grain size observed in an actual weld? or, second, a hardenability test may be made on the steel quenched from a temperature high enough to produce a grain size comparable to that found in the heat-affected zone.8 In order to obtain grain sizes in the end-quench hardenability bar comparable to those resulting in the base metal from the welding cycle, a quenching temperature of 2Ioo°F. has been used. In studies of the end-quench hardenability specimen quenched from 2Ioo°F. instead of from a lower temperature of I7OO°F., it is impor-TaiiT to ascertain The relative cooling rates for various distances along the bar. It is a question as to whether the cooling occurs at the same rate or whether there is any significant difference from the standard cooling-rate curve published by Jominy and confirmed by others.4,5 This paper reports experimental evidence concerning the effect of quenching temperature on the cooling rates in the end-quench hardenability test. The effect of quenching temperatures on cooling rates has been studied by a number of investigators.6'7 French has considered this effect from both theoretical and experimental aspects. In French's studies on complete quenching of spheres and rounds, an increase in the quenching temperature caused an increase in the cooling rate at 720°C. at the center of the specimen. The center cooling velocity also has been shown to be dependent upon the surface per unit volume for the type of specimens studied; the velocity of cooling increases with an increase in the surface per unit volume. Three methods of indicating the rapidity of cooling of a body of metal during a quenching operation have been propped: I. The time it takes for the metal to cool from the quenching temperature to a temperature halfway between the quenching temperature and the temperature of the quenching medium (half-temperature time): Grossmann, Asimow and Urban7 justify the use of this criterion by the fact that the half-temperature time includes the temperature and time of incubation as well as the zone of formation of pearlite and, further, the data so derived accord very closely with experimental values. 2. The time interval the metal remains in a given temperature range; for example,

Jan 1, 1944

By R. D. Nelson, F. E. Bowman

Assumptions are made of ideal mixing and that the density of silver can be obtained by extrapolating reported liquid density-temperature data through the freezing point back to the temperature range of interest. The results of this procedure using liquid silver density data of Kirshenbaum et al.5 are presented in Table I1 where it is observed that agreement is everywhere within <0.1 pct and generally is within 0.05 pct. Because the Sn-Ag alloys are dilute, the assumption of ideal behavior is, therefore, probably justified. In conclusion, the densities of dilute liquid solutions of silver in tin have been determined. Even for concentrations as low as 0.1 pct, the effect of silver on the density of liquid tin is clearly measurable. This work also suggests that for dilute alloys at temperatures far below the freezing point of the solute metal, densities may be accurately calculated by extrapolation of the pure metal data without having recourse to physical measurement on the alloy itself. plutonium having a grain size of about 100 µ. This paper presents data showing that large elongations of fine-grained a Pu can be obtained by using slow deformation rates. Large plasticity, however, of a Pu in compression has been observed.4 Reductions in thickness of 90 pct have been observed with no edge cracking. These large reductions are accompanied by concurrent re-crystallization. The deformation modes, which are quite complex, have been studied extensively by observing the deformation microstructures of polished surfaces that had been deformed in compression.5-7 Although slip apparently is a predominant mode of deformation at room temperature, grain boundary sliding and concurrent recrystallization become more predominant at high a temperatures.4&apos;7 Although recovery occurs,8,9 no grain growth has been reported in a Pu even at temperatures near the a =ß equilibrium temperature (-115oC), which is 0.7 of the calculated melting temperature of a Pu.10 From studies on other materials, it appears that high elongations can be obtained in alloys when the THE purpose of this technical note is to present briefly some data revealing high ductility of a Pu, which is normally considered brittle. The very low ductility of a Pu in tension has been reported by many investigators.&apos;-3 Gardner,1 for example, reported that the total elongation of a Pu at a testing speed of 0.015 ipm is less than 0.1 pct at room temperature and only about 1 pct at 100°C. The only tensile creep studies that have been reported&apos; indicate no large ductility, but they were performed on relatively low purity

Jan 1, 1970

By C. W. Macgregor

The observation of the flow layers, or Luders&apos; lines, produced in mild steel when it is stressed into the plastic range often provides considerable useful information for the study of the fundamental mechanism of the plastic flow of metals. It is a commonly observed fact that as soon as the upper yield point in a mild-st&apos;eel tensile-test bar is passed, an unstable condition develops in the equilibrium, the load on the testing machine drops and if the surface of the bar contains a thin mill scale, the latter begins to flake off rapidly along certain "lines." These "lines" are ill reality traces of wedge-shaped flow layers and are formed by the inter-section of the surface of slip and the surface of the bar. The average plane of the flow layer itself has been found by various experimenters to be inclined at an angle of approximately 45" to the axis of the test bar. In a body of more complicated shape stressed in possibly a different man-ncr, the tangent planes to the flow layers at each point seem in many cases to be inclined at an angle of about 45" to the principal stress direct-tions at the point. As examples of the latter may be mentionecl the logarithmic spirals obtained when a rivet hole is punched in a thin plate, or when a tube is subject,ed to internal pressure only, etc. IIencc if the flow layers are observed from an experiment, the shear-st&apos;ress trajectories —the curves indicating the direct,ions of the maximum shearing stresses in the body—may then be approximately determined. Since the latter curves form an orthogonal family inclined at 45" to the principal stress directions, the family of principal stress trajectories, or the curves irldicating the directions of the principal stresses, may be thus obtained Although the discontinuous type of stress-strain curve at the yield point is commonly observed with test bars of mild steel, more recent experiments have shown that this is by no means the only material exhibiting this interesting phenomenon. A similar effect has been observed in zinc and cadmium crystals, by Becker and Orowai~; in duralumin and other aluminum alloys, by Dawidenkow,~Elam,~ Fell4 an(l others; in copper and copper-alloy crystals, by Elam;~ in brass by Elam;3 in brass wires by deForest;" in higher carbon steels, tungsten steel, and

Jan 1, 1939

By C. W. MacGregor

The observation of the flow layers, or Luders&apos; lines, produced in mild steel when it is stressed into the plastic range often provides considerable useful information for the study of the fundamental mechanism of the plastic flow of metals. It is a commonly observed fact that as soon as the upper yield point in a mild-st&apos;eel tensile-test bar is passed, an unstable condition develops in the equilibrium, the load on the testing machine drops and if the surface of the bar contains a thin mill scale, the latter begins to flake off rapidly along certain "lines." These "lines" are ill reality traces of wedge-shaped flow layers and are formed by the inter-section of the surface of slip and the surface of the bar. The average plane of the flow layer itself has been found by various experimenters to be inclined at an angle of approximately 45" to the axis of the test bar. In a body of more complicated shape stressed in possibly a different man-ncr, the tangent planes to the flow layers at each point seem in many cases to be inclined at an angle of about 45" to the principal stress direct-tions at the point. As examples of the latter may be mentionecl the logarithmic spirals obtained when a rivet hole is punched in a thin plate, or when a tube is subject,ed to internal pressure only, etc. IIencc if the flow layers are observed from an experiment, the shear-st&apos;ress trajectories —the curves indicating the direct,ions of the maximum shearing stresses in the body—may then be approximately determined. Since the latter curves form an orthogonal family inclined at 45" to the principal stress directions, the family of principal stress trajectories, or the curves irldicating the directions of the principal stresses, may be thus obtained Although the discontinuous type of stress-strain curve at the yield point is commonly observed with test bars of mild steel, more recent experiments have shown that this is by no means the only material exhibiting this interesting phenomenon. A similar effect has been observed in zinc and cadmium crystals, by Becker and Orowai~; in duralumin and other aluminum alloys, by Dawidenkow,~Elam,~ Fell4 an(l others; in copper and copper-alloy crystals, by Elam;~ in brass by Elam;3 in brass wires by deForest;" in higher carbon steels, tungsten steel, and

Jan 1, 1939

By C. B. Post, D. G. Schoffstall

A determinatioil of the hydrogen content of molten steel by means of the Vacuum-extraction method, as reported here, consists in first casting a sample of the bath in a bomb, so that the gases evolved during solidification are trapped for analysis. A portion of the cast steel sample is then prepared and heated at a temperature of 600" to 800°C. under high vacuum, and the gaser given off during this vacuum extraction (which are shown to be hydrogen), are collected and measured. Analysis of the gases evolved on solidification and the gases in the solid sample enables an accurate determination of hydrogen in the molten steel. Fig. I shows the bomb and accessories that have been found suitable for trapping the gases evolved on solidification. The bomb is made of scamless steel pipe, approximately 7 in. long by 136 in. i.d., and welded at the bottom. An ordinary pipe cap has a vacuuni-type metal stopcock threaded and brazed in its upper end. This pipe cap fits onto the bomb by means of machined threads. A flange is brazed to the pipe at the point where the cap starts to tighten up, and a rubber gasket is placed between the flange and cap. Heavy vacuum grease is used between the flange and gasket and the gasket and cap. The weight of the complete bomb and it? interval volume is known before the sample is cast. In practice, a sample of about 400 grams of steel is poured into the bomb, the funnel quickly swung out of the way, the bomb cap spun down the threads and tightened against the gasket, and the bomb set in a pail of water to keep the gasket and vacuum grease cool. It is estimated that at least 80 per cent 01 the gases evolved from the liquid sample during solidification are trapped in the bomb."

Jan 1, 1945

By Henry M. Howe

This paper is a discussion of the extremely valuable one of Mathewson and Phillips, The Recrystallization of Cold-Worked Alpha Brass on Annealing,1 which not only gives us a wealth of important data reached with great intelligence, but also shows both uncommon powers of imagination and a perfectly fair spirit. Let me try to analyze some of their results, and to enunciate some of the laws to which these results point. For brevity I refer to them as "The Authors." The page numbers in parentheses refer to their paper. 1. The Visible Aspects of Recrystallization.—Plastic deformation in a single direction, as in cold-rolling, draws the grains out in that direction, that is, inequiaxes them, without destroying their apparent individuality. Each grain seems to endure the drawing out without changing either its volume or its orientation materially, for the etching tint of each grain seems to be as uniform after as before the drawing out, save for the "etch bands,"2 shown in Figs. A to D of the Authors&apos; Plate I. As the drawn-out metal is heated progressively, on reaching a certain "disintegration temperature" these old grains seem to break up, probably into submicroscopic fragments, and this apparent disintegration is followed by a coalescence of these fragments, so that their number decreases and their size increases, till they may become very much coarser than before the drawing out. Ruder3 coarsened the grains of silicon steel in this way till single grains reached an area of 50 cm. (7.75 sq. in.). The deformation itself probably breaks each grain up into many very small fragments, but the fact that each grain continues to have a uniform etching tint different from that of its neighbors indicates that these fragments retain the initial common orientation of the grain. The apparent disintegration which we observe, then, is rather an abandonment of community of orientation for individuality of orientation, by the fragments formed earlier during the deformation. Hence we

Jan 1, 1917

By A. E. Jenkins, O. C. Roberts, D. G. C. Robertson

Using an inverted-cone coil at 450 kHz, it has been possible to levitate iron (FeS), cobalt (CoS), and nickel (NiS) sulfides. Important nontransition metal sulfides such as ZnS, PbS, and Cu2S have proven impossible to levitate although Cu-Fe-S ternary alloys containing 30 wt pct S and up to 10 wt pct Cu, and Cu-Co-S and Cu-Ni-S ternary alloys containing 30 wt pct Cu have been levitated. The levitation technique has been used in preliminary experiments on the vaporization from liquid sulfides and the reaction of liquid metal-sulfur alloys with oxidizing atmospheres. The course of the reactions with pure oxygen were followed using highspeed photography and two-color pyrometry. ELECTROMAGNETIC levitation is now established as a basic laboratory technique in high-temperature research but its application has been restricted mainly to metals and alloys. Applications have included alloy preparation,&apos; metal purification,2&apos;3 determination of liquid metal densities and emissivities,4,5 and studies of metal supercooling,4 alloy thermodynamics,6 and vaporization phenomena.7-9 The application of the technique to compounds has not been considered previously. The successful investigation of the reactions between dilute iron alloys and oxidizing atmospheres10&apos;1 has prompted the current physico-chemical studies involving levitated metal sulfide drops and flowing inert or oxidizing atmospheres. This paper presents the results of such a study and provides a basis for future studies involving a wide range of other compounds of metallurgical interest. The successful levitation of many metal sulfides and mattes provides a method of studying the oxidation reactions fundamental to flash-smelting and similar pyrometallurgi-cal operations under closely controlled laboratory conditions. In addition the system allows the use of a controlled atmosphere (e.g., a gas stream of a certain H2/H2S ratio) with a particular chemical potential to study the relevant thermodynamic equilibria or the mass transfer processes between the atmosphere and the levitated drop under conditions where the hydrodynamics of the system can be closely defined. The optimum frequency for the levitation melting of metals in an inverted-cone coil type inductor is within the radio frequency range 400 to 500 kHz. At frequencies lower than 10 kHz the rate of heat generation is usually insufficient to melt the levitated charge&apos; or where melting is achieved, "dripping" from the charge is encountered.&apos;&apos; At frequencies above 2 mHz the levitation force decreases. Metals, alloys and preheated elemental semiconductors such as germanium and silicon, have been levitated but the levitation of only a few metal compounds has been reported. Jostsons13 and the authors have levitated liquid titanium-oxygen alloys containing 50 at. pct 0 while clark14 has reported the levitation of mixtures of FeS and MnS for short periods. With a "cold crucible" inductor sterling15 has melted ferrites by preheating them by induction in a 4 mHz field and melting at a lower frequency. However this second type of inductor has been designed purely for the melting of materials without contamination; there is only a small gas film between the charge and the inductor and the electromagnetic levitation effect is of secondary importance. For this reason further discussion will be restricted to the use of the coil type inductor. The assessment of the suitability of a particular metal compound for levitation is based upon the following two criteria: i) thermal stability, and ii) physical "levitability". In this paper these two criteria will be considered separately. The thermal stability of a solid or liquid metal compound with respect to a gaseous environment depends upon its chemical reactivity with that environment or, in the case of an inert atmosphere considered here, its volatility. The physical criterion as to whether or not a particular compound can be levitated is based upon a comparison between those physical properties of the compound determining "levitability" which are defined by the fundamental equations of levitation theory as developed by Okress et a1.,16 and the properties of the metals. Since it is not practical to cover the vast field of metal compounds, further discussion will concentrate on the metal sulfides but the treatment would be applicable to any metal compound. THE THERMAL STABILITY OF METAL SULFIDES The temperatures usually encountered during levitation in inert atmospheres cover the range 1400" to 2000°C. The stabilities of the condensed states of the sulfides under these conditions are considered in relation to the periodic classification by reference to Table I. Two general classes of sulfides emerge. The solid sulfides of elements of group IIB and of groups further to the right are volatile while those sulfides of group IB and of groups further to the left are nonvolatile solids. The sulfides described as volatile may be dismissed as unsuitable for levitation. The stabilities of the more favorable nonvolatile sulfides under the anticipated conditions must be studied more closely From Table I it is seen that the alkali metal sulfides exist as liquids in the temperature range of in-

Jan 1, 1970

By James B. Graham, Earle E. Smith

The value of all minerals produced in the United States for the years 1930 to 1932 averaged $3,460,000,000 annually, according to Bureau of Mines reports. Of this amount, approximately $1,280,000,000 represents nonmetallic substances, such as petroleum, gas, sulfur and salt produced as fluids. Thus, about.37 per cent of the country&apos;s mineral wealth is procured through wells drilled in the earth, which require casing to keep them open throughout their life. Deep well drilling has increased greatly in the last few years. Several strings of casing have been set deeper than 9000 ft.—one, a string of 7?-in. O.D. casing, 10,301 ft. long, run in a well drilled by the Gulf Production Co. in West Texas, holds the record up to this time. These are longer strings than were contemplated when the American Petroleum Institute Specifications were adopted 10 years ago, therefore it is necessary to consider whether the present joint standards are adequate for such strings, or for even longer strings that may be called for in the future. Petroleum engineers are asking: Is there a possibility that stronger joints can be designed without going to stronger and more costly steels than offered in present specifications? Without sacrificing too greatly the tensile properties of the joint, can its design be changed to allow more clearance in the open hole below the next larger string of casing, and thus avoid costly underreaming? What can manufacturers offer for drilling through heaving shale? Fundamentals of the Problem During the last few years considerable study has been given to casing joints and their limitations, and since attention must be given to this subject by those who will be required to drill deeper holes, it is timely to review the fundamentals of the problem. These will be recognized generally as the following: 1. No threaded joint can be stronger than the area of metal under the root of the first perfect thread, and this area must be large enough

Jan 1, 1935

By Harrison Everett Ashley

Prof. Hofman&apos;s diagrams, Figs. 5 and 7 of his paper, which are reproduced as Figs. 1 and 2 of the present contribution, confessedly fail to show comprehensively the properties of the silicates investigated. Each curve is carefully discussed, and the author has evidently drawn all the conclusions that can be thus reached; but he says :* "The curves do not show, as was hoped, any simple connection between silicate-degree, percentage of lime, and minimum of formation-temperature." There is, therefore, in this case, an excellent opportunity of

Jan 1, 1902

By L. T. Larson, P. M. Basinski

In the northern Reese River Valley uranium is corroded with Middle Pliocene zeolites. These zeolites were diagenetically derived from rhyolitic volcanic glass deposited in a saline- alkaline lake. X-ray diffraction, scanning electron microscopy, and chemical studies reveal clinoptilolite, analcime, and enonite to be pesent and that these minerals can concentrate at least 0.7% uranium from solution. Most anomalous drill cuttings contain zeolite and zeolites are believed to host the uranium. Research suggests the uranium mineralization is conceptually analogous to the Tono mine, Japan.

Jan 1, 1981

By Theron Wasson

During 1936 the state of Michigan produced 11,868,573 bbl. This is approximately 4,000,000 bbl. less than produced in 1935. The principle reason for the decrease in production over the previous year was the rapid decline of the Crystal field, which reached its peak in October 1935. The old producing area—Mt. Pleasant, Porter, Yost-Clark— accounted for over 7,000,000 bbl. during 1936. Crystal produced a total of 2,400,000. Outstanding among the old fields were Vernon and

Jan 1, 1937

By J. P. Zannaras

Referring to the article by R. J. Charles and P. L. de Bruyn, let us assume that W = weight of glass bar; P = weight of hammer; e = total deformation; E = unit of deformation; K = potential stress energy; E = modulus of elasticity; L = length of the bar; 7, = coefficient of inertia; h = height, ft; V = velocity, fps; and a = cross section area. The portion of kinetic energy which is effective in producing stress energy in a fixed bar struck horizontally is given by the formula [ ]

Nov 1, 1956