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By Michael Hoch, Daniel B. Butrymowicz

The isothermal section of the Ta-Ti-Zr-0 system at 1500°C was investigated using X-ray diffraction and rrzetallographic techniques. Up to 71.4 at, pct 0 the system contains nine four -phase regions. Zsopleths at 10, 20, 30, 40, 50, and 60 at. pct 0 were constructed. The purpose of this investigation was to determine the general shape of the quaternary equilibrium phase diagram of tantalum, titanium, zirconium, and oxygen at 1500°C. The system was truncated at 66.7 at. pct 0 on the Ti-0 and Zr-0 binaries and at 71.4 at. pct 0 on the Ta-0 binary. The Ti-Zr-0 system was investigated in this laboratory.' The binary systems of interest have been compiled and discussed by Hansen and Anderk, chmidt, Hayes, Roberson, and asche, and Hoch and athur.' EQUIPMENT The Same equipment as that for the study of the Nb(Cb)-Ti-Zr-0 system was used.' The X-ray dif- fraction patterns were analyzed with the help of the ASTM card set7 and NBS circulars.' MATERIALS The tantalum powder (99 pct pure), the titanium powder (99.6 pct pure), the tantalum pentoxide, and the zirconium dioxide used in this study were purchased from the Fairmont Chemical Co., Newark, N.J. The zirconium powder (99.4 pct pure) was obtained from the Charles Hardy Co., Inc., New York. Reagent-grade titanium dioxide was purchased from the Matheson Co., Inc., Norwood, Ohio. The oxides were dried in air at 700°C for 24 hr before use. Though the materials used were not "hyper-pure", the impurities present do not affect the results (lattice parameters, phase boundaries), within the experimental accuracy. PROCEDURE The samples were heated by induction in a vacuum furnace, and examined metallographically and by X-ray diffraction at room temperature. The procedure was the same as that in the Nb(Cb)-Ti-Zr-O work,' EXPERIMENTAL RESULTS AND DISCUSSION OF DATA A four-component system can be represented by a tetrahedron at a single temperature and pressure

Jan 1, 1964

By L. H. Levenson, Charles S. Barrett

Numerous determinations1-' of the texture of cold-rolled polycrystalline iron, steel, and ferritic alloys have been made with good agreement among the various observers as to the principal features of the texture common to all, but there has been no adequate explanation of the texture in terms of, the behavior of individual grains. This study presents an explanation of the texture based on the observed rotation of single crystals when deformed in a manner similar to a grain in the aggregate, a method we have found useful in leading to a better understanding of compression and tension textures;8,9,10 in particular, the aim has been to determine experimentally the end orientations of rolled single crystals of iron. These are discussed in connection with the point of view of Weverl and of Boas and Schmid2 that the rolling texture is a simple compression texture (compression normal to the rolling plane) superimposed on a simple tension texture (tension in the rolling direction), and the point of view of Kurdjumow and Sachs3 that three ideal end orientations exist. Experimental Method The single crystals used were in the form of disks cut from a stock of crystalst pre- pared in this laboratory by a strain-anneal method from mild steel decarburized and purified in hydrogen, the details of which have been described elsewhere.11 To ensure maximum elongation in the rolling direction and to simulate approximately the rolling of a grain in an aggregate, lateral flow was constrained by placing each crystal in a close-fitting hole in a plate of copper or iron of equal thickness and rolling the plate and crystal together. About one-third of the crystals were rolled in a "sandwich" pack by adding top and bottom cover plates. The two-high mill used had 8-in. diameter rolls and was operated at 15 r.p.m. The initial diameter of the crystals was between 1/4 and 1/2 in., while the starting thickness varied from 0.031 to 0.376 in. With a single exception, which was rolled 63 per cent, the crystals were rolled to a final reduction in thickness of 82 to 97 per cent in 20 to 40 passes, alternately changing the sense of the rolling direction. The initial orientations of the crystals were determined either by X-ray back reflection12 or by optical reflectionl3 from etch pits; the mean final orientations were determined by X-ray Laue photograms using molybdenum, silver, or tungsten radiations, by optical reflection, and in many cases by both methods. Results Twenty-six crystals were studied. It was found that there were three typical be-

Jan 1, 1941

By Charles S. Barrett, L. H. Levenson

Numerous determinations1-' of the texture of cold-rolled polycrystalline iron, steel, and ferritic alloys have been made with good agreement among the various observers as to the principal features of the texture common to all, but there has been no adequate explanation of the texture in terms of, the behavior of individual grains. This study presents an explanation of the texture based on the observed rotation of single crystals when deformed in a manner similar to a grain in the aggregate, a method we have found useful in leading to a better understanding of compression and tension textures;8,9,10 in particular, the aim has been to determine experimentally the end orientations of rolled single crystals of iron. These are discussed in connection with the point of view of Weverl and of Boas and Schmid2 that the rolling texture is a simple compression texture (compression normal to the rolling plane) superimposed on a simple tension texture (tension in the rolling direction), and the point of view of Kurdjumow and Sachs3 that three ideal end orientations exist. Experimental Method The single crystals used were in the form of disks cut from a stock of crystalst pre- pared in this laboratory by a strain-anneal method from mild steel decarburized and purified in hydrogen, the details of which have been described elsewhere.11 To ensure maximum elongation in the rolling direction and to simulate approximately the rolling of a grain in an aggregate, lateral flow was constrained by placing each crystal in a close-fitting hole in a plate of copper or iron of equal thickness and rolling the plate and crystal together. About one-third of the crystals were rolled in a "sandwich" pack by adding top and bottom cover plates. The two-high mill used had 8-in. diameter rolls and was operated at 15 r.p.m. The initial diameter of the crystals was between 1/4 and 1/2 in., while the starting thickness varied from 0.031 to 0.376 in. With a single exception, which was rolled 63 per cent, the crystals were rolled to a final reduction in thickness of 82 to 97 per cent in 20 to 40 passes, alternately changing the sense of the rolling direction. The initial orientations of the crystals were determined either by X-ray back reflection12 or by optical reflectionl3 from etch pits; the mean final orientations were determined by X-ray Laue photograms using molybdenum, silver, or tungsten radiations, by optical reflection, and in many cases by both methods. Results Twenty-six crystals were studied. It was found that there were three typical be-

Jan 1, 1941

Following closely Marcona Corp.'s announcement of its new Marconaflo process for transporting mineral slurries by ship (see pp. 96-97, Sept. 1969 [ ]), Midland-Ross Corp. (M-R) now heralds its metallized iron pellet process which supplements Oregon Steel Mills1 (Oregon Steel) new Portland, Ore., plant. Harry J. Bolwell, president of M-R describes the company's M-R Pellet as "the most exciting advance in steelmaking in a decade, one which will profoundly affect the industry." In fact, other knowledgeable industry spokesmen believe that with these developments the mini-steel plant era is now here and that this technical development along with the Marconaflo process will revolutionize iron ore shipments and steelmaking. The M-R president predicts that electric furnaces can account for 20% of the annual U.S. steel production by 1975, compared with 14% at the present time because of these developments.

Jan 12, 1969

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

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

Jan 1, 1961

By H. O. Hofman

The sudden decease, April 1, 1910, in Chicago, of Dr. Franklin R. Carpenter was a shock to his many friends. He died in his sixty-second year, of heart paralysis. To most fellow-members of the Institute who have followed the progress of the last twenty-five years in the mining and treatment of non-ferrous ores, the work of Dr. Carpenter in that line is familiar; but very few, even of those who knew hinl well in the later years, are acquainted with his earlier struggles to satisfy an inborn hunger for knowledge. The story of his life resembles that of the pioneer who opens up new country; overcoming hardships with indomitable courage, meeting doubts and difficulties with an alert and open mind, and exercising in the face of reverses an unconquerable perseverance. It seems appropriate to place on record in the Transactions a brief outline of the life and work of this eminent engineer. During the past 15 years of his life Dr. Carpenter was much interested in genealogy. In the pursuit of this study as an avocation, he traced his own ancestry to the time when ((Hugh," called "le Charpentier" on account of the dexterity with which he had swung his battle-axe as a crusader, settled in Sussex on lands received from William the Conqueror. The Carpenters came to this country with William Penn. A prominent member of the family was Joshua Carpenter, the founder of Christ Church, Philadelphia. Dr. Carpenter's branch of the family moved from Pennsylvania into that part of Virginia which is now West Virginia, where his grandfather settled in Harrison county, while the grand-uncle went further west, and built the first iron-furnace at Hanging Rock, Lawrence county, Ohio. In fact, since early times, the Carpenters appear to have been iron-masters. Franklin R. Carpenter mas born, Nov. 5, 1848, in Parkers-

Jan 1, 1911

By P. T. Gallagher, W. A. Oates

THE partial excess entropy of interstitial solutes in metals, SXS , has usually been interpreted as being principally vibrational ever since the initial statistical treatment of hydrogen in metals by Fowler and Smith-ells. The vibrational entropy is considered being due to the optical modes of the light interstitial atom. Little attention has been given to the magnitudes of the values of SXS'. Leiser and Witte2 and Ebisuzaki and O'Keeffe3 have noted that for hydrogen in metals Si is approximately constant for different metals. On the other hand if it is assumed that the interstitial solute is an isotopic defect then, as shown by McLellan, SXS should vary from metal to metal as follows: where S is the standard entropy of the solvent and Mi, M, are the masses of the interstitial and solvent atoms. respectively. Fair agreement with this equation was found for oxygen in silver and nitrogen in iron4 and for carbon in iron.= Ln a subsequent analysis of metal- hdrogen systems McLellan' found a variation of $' from metal to metal but not in a manner expected from the isotopic impurity equation. However, a possible correlation between the energy of solution, Ei, and sf was noted. Similar correlations have been noted for certain dilute substitutional solid Solutions 7, 8 and recently Kubaschewski 9 has demonstrated a correlation between integral heats and ex-

Jan 1, 1970

By D. H. Thompson, A. W. Tracy

Season-cracking is a type of failure of brass that results from the simultaneous effect of stress and certain corrodants. The object of this paper is to present data that will aid in a more complete understanding of the mechanism of season-cracking and related phenomena. Results presented show that certain high copper alloys are susceptible to season-cracking or stress-corrosion cracking, and possible explanations are discussed. Starting at least as far back as 1906, many papers have been devoted to this subject but the symposium1 held in Philadelphia in 1944 is the richest source of information. In order to study season-cracking, several of the many variables were held constant so as to learn the effects of others. Season-cracking is generally understood to refer to the corrosion cracking of brass having internal stresses;²,³ it is a special case of the general stress-corrosion cracking. Inasmuch as applied stresses are more readily produced and controlled, they were used exclusively in this research and the resulting phenomenon must he called stress-corrosion cracking.²,³ Only constant tensile stresses were used. The agents believed to be most frequently responsible for season-cracking are ammonia. amines and compounds containing then]. Both moisture and oxygen also appear to he necessary. Therefore, an atmosphere containing ammonia, water-vapor and air was selected for these tests. Briefly, the work consisted of exposing sheet metal specimens, having a reduced section ¼ by 0.050 in., of copper-base alloys to the effect of static tensile stresses between 5,000 and 20,000 psi and simultaneous contact with a. continuously renewed atmosphere containing 80 pct air, 16 pct ammonia and 4 pct water vapor at 35°C. The gas mixture and the speci- mens were maintained above the dew-point. The time-to-failure in minutes was the primary measure of results. In order to limit the experiment to finite time, it was considered that a specimen which had neither failed nor undergone microscopically detectable cracking in 40,000 min. (4 weeks) while under a stress of 10,000 psi or more could be considered immune to cracking. This is merely a convenient limit and is not to be considered proof of immunity. Supplementary tests in the absence of stress using weight loss or microscopical appearance as measures of attack were made. Apparatus The apparatus used in this research is shown in Fig 1. To facilitate the description it may conveniently be divided into six parts: stress-producing units, test chamber, gas train, electrical controls, timers and gas analysis device. A stress-producing unit is shown in an exploded view at the left in Fig 2. At the right is an assembled unit with a specimen in place in the lower portion; it is this part that remains in the ammonia atmosphere during a test. The upper part contains a spring, a central threaded rod, a large nut and necessary washers, pins, and so forth. Stress is produced in the specimen by screwing down the top nut against the spring, thus putting a tensile load on the central rod and so on the specimen. The wrench that turns the nut by extending through the upper cap, is seen at the upper right of the figure. The magnitude of the load is gauged by measuring from the pin that extends through the side of the tube, to a fixed point on the large flange. Measurement is made with a vernier beam caliper, shown at the right of the figure. The necessary spring compression to give a desired stress is calculated from the calibration curve of the spring and the dimensions of the specimen. The test chamber, center Fig 1, consists of a thermally insulated steel box 32 in. long by 10 in. high by 7 in. wide. A horizontal baffle reaching nearly to each end divides the chamber equally. Below this baffle are inlets for air and ammonia, a heating coil and a fan. Thus the gases are warmed and mixed in the lower level and flow past the specimens in the upper level. A thermo-regulator and thermometer project into the upper space. The top is pierced by 12 ports flanked by 3/8 in. threaded studs. A test starts when a port is opened and a unit containing a stressed specimen is thrust through it and bolted down against a neoprene gasket. The test chamber is held at 35°C. The gas train, right rear Fig 1, carries ammonia and air continuously to the test chamber. Tank ammonia passes through two reducing valves, a needle valve, a flow meter and into the test chamber. The air from either the plant compressor or a small laboratory compressor passes through wool towers and flow controls to the flow-meter. It then bubbles through water at 34°C and through a heated line to the test chamber. Electrical controls, left rear, Fig 1, provide rectifiers and mercury relays for the test-chamber and humidifier-heating-control circuits and outlets for

Jan 1, 1950

By H. M. Chance

HAVING an opportunity of exhibiting specimens of .coal from two beds in this field to the members of the Institute, I desire only to

Jan 1, 1885

By Richard Moldenke

A. E. OUTERBRIDGE, JR., Philadelphia, Pa. (written discussion).¬ The fact that iron castings improve with age has long been known. Many years ago the late Sir Frederick Bramwell, a distinguished engineer, formerly in charge of the metallurgical and gun-making department of the Woolwich Arsenal, England, determined to break up a large number of cast-iron mortars of an obsolete type that had been in stock for years. It was then reported to biro that it was found to be much more difficult to break these old gun castings under the "drop" than it was to break similar gun-castings recently made, under his own supervision; he changed the.. composition of the iron and still found that whenever castings made recently were broken up (on account perhaps of superficial defects) great disparity was observed in apparent strength between the old and new castings. Sir Frederick then made many other comparative tests, such

Jan 4, 1917

By G. L. Fisher, R. H. Geils

The effect of small amounts of columbium (<0.01 to 0.10 pct) on the ?-a transformation occurring during the continuous cooling of a low carbon Ni-Cu steel was investigated. Dilatometer specimens were aus-tenitized at 950" and 1068?C and cooled at 17? and 375 C° per min. Columbium caused a marked depression in the ?-a transformation temperature except when cooling at the slower rate from 950°C. The effec of columbium on the transformation temperature was greater the higher the austenitizing temperature and rate of cooling. A maximum depression of 92 C" was observed. Metallographic examination of specimens of <0.01 and 0.07pct Cb steels heated at 1200°C for 1 hr and cooled at various rates showed that columbium had a major effect on the ferrite morphology. The fer rite in the columbium -free steel remained equiaxed at cooling rates as high as 440 C? per min while the columbium-bearing steel exhibited mixed structures o equiaxed and bainitic ferrite at cooling rates as low as 130 C° per min. The ? grain boundaries in the columbium -free steel provided the ferrite nucleation sites in rapidly cooled specimens. There was a complete absence of nucleation at these sites in the colum bium-bearing steel. It is concluded that columbium depresses the transformation temperature by suppressing ferrite nucleation at the austenite grain bound-aries. In this respect the effects of columbium are analogous to those of boron in low C-Mo steels. It is well known that small columbium additions can substantially strengthen plain carbon steels. As little as 0.02 pct Cb can increase the yield strength of mild steels by 10,000 psi.1 A fine precipitate of CbC has been observed in columbium-bearing steels2 and is generally thought to be responsible for the strengthening. Little attention has been devoted to the effect of columbium on the ?-a transformation. Webster and woodhead3 have studied the effect of columbium on the isothermal proeutectoid ferrite reaction in mild steels. They found similar transformation behavior in steels both with and without columbium additions. However, as the austenitizing temperature increased, the incubation time for the start of the ferrite transformation became longer in the columbium-containing steel. Morrison1 found that the addition of 0.03 pct Cb to a C-Mn steel lowered the transformation temperature by 50 C° during cooling from 1200°C at a rate of 80 C" per min. The strengthening effect of columbium has recently been utilized in an age-hardenable, low-alloy steel containing copper and nickel.4 A small amount of columbium has a substantial effect on the as-rolled strength of this steel. By increasing the columbium level from <0.01 to 0.13 pct the as-rolled yield strength is increased by 15,000 psi. Columbium also significantly lowers the ?-to-a transformation temperature of this steel during continuous cooling from the austenitizing temperature. Because of the low carbon level in this steel (0.05 pct max), it is almost entirely ferritic. Thus, it offers the opportunity of studying the effect of small columbium additions on the proeutectoid ferrite reaction. Of particular interest in this study was the reason for the marked lowering of the transformation temperature by columbium during continuous cooling. EXPERIMENTAL PROCEDURE Materials. The compositions of the steels used in this investigation are shown in Table I. The steels were 30-lb air induction melts. They were forged to 4 by 8 by 1 in. plate at 1230°C, air cooled, and then reheated to 1230°C and cross-rolled in two passes to in. plates. Dilatometry. A Leitz Bollenrath dilatometer was used to record the transformation during continuous cooling from two different austenitizing temperatures. The dilatometer specimens were + in. in diam and 2 in. long. Oxidation and decarburization of the specimens was prevented by maintaining a small positive pressure of dry argon in the dilatometer furnace and by plating the specimens with 1 mil of Cu. For the lowest cooling rate, 17 C" per min, the temperature of the specimen was measured with a Pt-Pt 10 pct Rh thermocouple placed in a & in. diam well in the center of the specimen. During air cooling, 375 C° per min, this method of measuring the temperature interfered with the operation of the dilatometer. However, it was found that the temperature of the specimen could be measured accurately by placing a thermocouple in an identical specimen in a holder adjacent to the one being used to operate the dilatometer mechanism. The dilation-temperature curves were recorded on photographic film and then converted to volume percent ferrite-vs-temper-ature curves. The cooling rates obtained with the dilatometer are shown in Table 11. Cooling rates of

Jan 1, 1970

By John D. Price

R. W. Campbell (Jones and Laughlin Steel Carp., Pittsburgh)—As usual John Price has presented an excellent paper. I know of no one who has devoted more time and conscientious thought to this subject than he has, and his efforts have produced scientific data and conclusions of real value. Results of similar studies made by the Jones and Laughlin Steel Corp. on the blending of Pennsylvania coals may be of interest. During 1935 the late F. W. Wagner and the present writer developed an empirical physical fuel value formula for evaluating the combined physical tests of metallurgical coke, see Table IV. In the development of the formula, the tumbler test, shatter test, screen test, and porosity of coke have been taken into consideration. Each of these tests brings out some physical property not expressed by the others, and in estimation of the importance of these tests as a medium for evaluating coke for the blast furnace, their worth has been graded as follows: It was thought that some additional penalty should be applied to cokes that do not show a uniform screen size, assuming that coke larger than 4 in. was not desirable and that this size was an indication of irregular size. Therefore the screen test factor is further corrected by applying a penalty of 1 pct for each 1 pct material greater than 4-in. size as shown by the screen test. The physical fitness of coke for blast furnace use depends upon four fundamental characteristics: l—gen-era1 strength, as indicated by the shatter test; 2— abradability, or the resistance of cell walls to reduction in size by attrition, as indicated by the tumbler test; 3—porosity; and 4—size and uniformity. Each of these characteristics is not of equal importance, but surely, in an attempt to determine an accurate physical value, the individual value of each should be taken into consideration. The formula is used as a yardstick, so to speak, in determining variations in the normal production of metallurgical coke and in making comparisons between normal coke and experimental blends with other coals. Table IV gives results of coking tests on raw and washed high volatile coals and these same coals with blends of coke breeze, anthracite coal, char and low volatile coals, all from Pennsylvania. The table also gives the source of the coals and coke breeze, as well as their proximate analyses. It will be noted that the washing of the raw high volatile coal increased the physical fuel value from 26.17 to 39.16, showing the effect of removing shale and slate which produces a detrimental fracturing and weakening of the coke. It is a well known fact that many Pennsylvania high volatile coals contain an excess of resinous material or binder which has a tendency to weaken the coke, owing to its high evolution of gases during carbonization. Tests were therefore made with coke breeze, an inert material, in an attempt to alleviate this condition. Blends of washed coal with 5 pct and 7.5 pct coke breeze collected from the coke plant quenching sump (82.9 pct through 1/8-in. screen) resulted in cokes with a physical fuel value of 20.75 and 16.73 respectively, lower than results obtained from 100 pct raw high volatile coal. It will be noted that the percentage of + 4-in. coke increased but that the tumbler test was very low. Undoubtedly better results could have been obtained if the coke breeze could have been crushed extremely fine. During World War II the government asked the coking industry to consider the use of anthracite coal as a substitute for high quality low volatile coal, which was extremely scarce at the time. The next series of tests was made with blends of raw and washed high volatile coals and 5, 10, and 15 pct Pennsylvania No. 5 buckwheat anthracite (100 pct through l/8-in. screen). It was necessary to use some raw high volatile coal in these blends because of insufficient washer capacity at the time. It will be noted that the physical fuel values

Jan 1, 1954

By H. I. Young

Inasmuch as there has been a great deal of activity in this district recently, a paper of this kind should treat of all the various phases of mining, namely, prospecting, developing, and operating. Prospecting .. Where ore is found at a depth of 100 ft. (30 m.) or more, the prospect work is done by churn drilling. Several makes of churn drills are used in this work, both steam- and gasoline-driven machines being used. The drilling is usually started with a 6-in. bit, and the size of the bit is reduced, if necessary, as the hole is advanced. It is general practice to drill from 100- to 400-ft. holes, but this is governed entirely by the location and formation of the ground. In drilling sheet ground, close spacing of drill holes is unnecessary, but in narrow orebodies, the holes are spaced from 15 to 50 ft. (4.6 to 15 m.) apart. Ten years ago, very few assays were kept of the drilling, but during recent years records have been kept very accurately, showing the location, elevation, assays, and also the vertical section of the hole. After the orebody is reached, cuttings are taken every 2 or 3 ft. (0.6 to 0.9 m.) samples being sometimes taken by pouring the water off the cuttings and taking a portion of the coarse material for assay. It has been found, however, that very often the sludge material poured off with the water contains high mineral values. To overcome this, cuttings from each 2 or 3 ft. are put in a container, and, after the water is evaporated, sample for assay is taken by means of Jones samplers. Permanent records of cuttings showing various formations are kept in glass jars or glued on large cards. Drilling at present is costing from $1.25 to $1.50 per foot. In pre-war times, the drilling costs ran from 75c. to $1 per foot. Development After proving property by drilling, shafts are put down to the ore-body. These are usually vertical shafts, either single or double compart-

Jan 1, 1918

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&apos; 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&apos; estimated that the tattice constant of a Fe at 25°C increases 0.0014A per wt pct Cu in solution. Extrapolating Norton&apos;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 R. Kossowsky

USING etch-pit techniques, Johnston and Gilman&apos; have shown that the stress dependence of dislocation velocity can be represented by the expression where r, is the dislocation velocity, a is the applied stress, and oa, is the stress to produce a unit velocity. Noble and Hul12 showed that the exponent m is strain-dependent and increases rapidly in the work-hardening region. This was explained by arguing that in the work-hardened material the applied stress required for any given velocity will be greater than in the annealed material by an amount equal to a back stress due to work hardening. schadler3 has stressed the importance of substructure as a possible source of error in dislocation velocity measurements, and took care to make velocity measurements in which dislocations moved such short distances that interactions with boundaries were avoided. schadler3 also pointed out that, if standard testing equipment is used, measurements of m from flow stress data could be seriously in error in materials with a high initial work-hardening rate. Noble and Hu112 have further argued that, due to the strain dependence of m , the extrapolation to zero strain4 to obtain the true value of m can be justified only in the preyield region. Microstrain experiments in high-purity iron5,6 have led to the conclusion that aiA (Ref. 5) (defined as the stress to first produce a permanent set of 10-6 in. per in.) and oflow are not controlled by the same deformation mechanism. It has been proposed5,6 that aA is governed by the lattice resistance to the motion of screw dislocations in a given slip plane and that oflow is controlled by the lattice resistance to a full-scale cross slip. The purpose of this note is to extend Noble and Hull&apos;s argument further and to show that measurements of m from flow stress data can be in error due to the rapid increase in stress in the microstrain region6 when stress is increased beyond aA. Double z-one-refined single crystals of molybdenum (with the (101)[ 111] slip system operating and a Schmidt factor of 0.475) were used in an experimen-

Jan 1, 1968

By Donald Barton

THE theory of gravitation is based on Newton&apos;s law that any two bodies exert a mutual attraction which is proportional to the product of their masses and inversely proportional to the square of the distance between them; i. e., A =KRM/R2 (1) where K is a constant, M and m are the respective masses of the two bodies, and R the distance between them. In the earth&apos;s gravitational system, the earth is one of the bodies; the other may be any body within or without the earth. In theoretical dis¬cussions and calculations in regard to gravity, that other body usually is taken as a unit of mass: in the C. G. S. system, a body of one gram in mass. GRAVITY AND LEVEL SURFACES Gravity is defined in geophysics as the force of attraction exerted by the earth, towards itself, on a body of unit mass. The intensity of gravity is usually expressed in dynes of force or in centimeters of acceleration. In geophysical work in America, most commonly it is expressed in dynes (per gram) with the "per gram" understood and not directly expressed. In geophysical work in Europe, most commonly it is expressed in centimeters per second per second (cm./sec.2) and less commonly merely as centimeter-gram-second units (C. G. S.). At sea level, the intensity of gravity amounts very nearly to 980 dynes. The vertical is the direction along which the attraction of gravity is exerted at any point. . In most cases, it is very nearly, but not quite, per¬pendicular to the earth&apos;s surface. The path that would be taken by a body falling freely through space toward the earth is vertical at each point and may be spoken of also as "the vertical," or as the line of the vertical, or as a line of force of gravity. At the earth&apos;s surface it com¬monly is very nearly, but not quite, a straight line.

Jan 1, 1928

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Jan 1, 1938

By Frank C. Greene

The wildcatting in northern and northwestern Missouri, which started in 1939, was continued in 1940. Two new gas fields were found and one discovered in 1939 was further extended. The total number of completions was 94, of which 5 were oil wells with about 48 bbl. initial production, 30 were gas wells with an initial open-flow capacity of 37,655,000 cu. ft., and 59 were dry holes. The outstanding discovery was the Polo gas field, T. 55 N., R. 28 and 29 W., in Caldwell County. A sand now believed to be a lens in the Bandera shale at a depth of 400 ft. yielded flows of more than 12,000,-000 cu. ft. In all, I0 wells with 31,490,000 cu. ft. of gas, were drilled. The rock pres-sure is 80 lb. At present no arrangements for an outlet have been made. In Platte County, the Prairie Point gas pool in sec. 7, T. 51 N., R. 33 W., and sec. 12, T. 51 N., R. 34 W., and the Lake-side pool in sees. 5 and 6, T. 50 N., R. 33 W., were further developed, and in the latter both oil and gas have been found, but data are not available for publication at this time. Drilling for gas continued in proven areas in Clay County, and for both oil and gas in proven areas in Jackson and Cass Counties. Table 1 summarizes the results of drilling in Missouri in 1940.

Jan 1, 1941

By Frank C. Greene

The wildcatting in northern and northwestern Missouri, which started in 1939, was continued in 1940. Two new gas fields were found and one discovered in 1939 was further extended. The total number of completions was 94, of which 5 were oil wells with about 48 bbl. initial production, 30 were gas wells with an initial open-flow capacity of 37,655,000 cu. ft., and 59 were dry holes. The outstanding discovery was the Polo gas field, T. 55 N., R. 28 and 29 W., in Caldwell County. A sand now believed to be a lens in the Bandera shale at a depth of 400 ft. yielded flows of more than 12,000,-000 cu. ft. In all, I0 wells with 31,490,000 cu. ft. of gas, were drilled. The rock pres-sure is 80 lb. At present no arrangements for an outlet have been made. In Platte County, the Prairie Point gas pool in sec. 7, T. 51 N., R. 33 W., and sec. 12, T. 51 N., R. 34 W., and the Lake-side pool in sees. 5 and 6, T. 50 N., R. 33 W., were further developed, and in the latter both oil and gas have been found, but data are not available for publication at this time. Drilling for gas continued in proven areas in Clay County, and for both oil and gas in proven areas in Jackson and Cass Counties. Table 1 summarizes the results of drilling in Missouri in 1940.

Jan 1, 1941

By Walter S. Lutz, J. T. Griffith

The rainfall during the last six months of 1942 in Scranton and vicinity was 24.06 in.—only 4.35 in more than the average for this district in any equivalent period—yet that rain forced The Hudson Coal Co. to handle 38.8 tons of water for every ton of coal mined. It filled to overflowing, or to a higher level, 14 flooded mine areas holding, in total volume, 8.3 billion gallons of water in storage; brought about a pumpage of 11.4 billion gallons in the months of December 1942 and January, February and March 1943 Half of the total energy generated or purchased (44,322,980 kw-hr.) was required to keep the mines sufficiently free of water to permit the mining of coal during a period of much needed output. Fig. I shows the extent to which this flooding of exhausted and idle properties has proceeded, and is known to be proceeding further, at the upper end of the Northern field. This rainfall (24.06 in.) means 80,559,444 tons of water on approximately 46.2 sq. miles of area tributary to the pumping plants. During the high rainfall period, 72,687,661 tons went underground, being pumped at the stations in this territory. This means an inflow of 88per cent, a runoff of 12 per cent compared with 64 per cent during normal conditions in a normal region. During this period no floods, either surface or underground, had to be dealt with, although the streams and rivers were high on several occasions. In general, the rainfall for the first three months of 1943 can be described as heavy but not abnormal.9 These figures not only indicate the large volumes of water to be handled but, by their very size, they also emphasize that the mine-water problem is not to be conquered, at least from an economical standpoint, by merely buying and installing more and more pumps. Into the solving of this water problem must go much planning, adhering to the principle of keeping the highest percentage of water at the highest possible level for the longest period of time; the storage of huge volumes in sumps capable of being reduced after the flood inflow and at rates less than the inflow; plans for prevention of surface inflow; provision of the minimum of pumping capacity arranged to as nearly 100 per cent pumping load factor as is possible; intercompany joint pumping plants; the conducting of water from one plant to another and from one property to another over distances measured in miles; priorities in power to the threatening situations; and. balance of the necessities and dangers existent in one colliery over another, day by day, when quantities of water are running high. Despite these astronomical figures of water volumes, their disposal to the surface is accomplished reasonably cheaply because, although the annual cost of $575,020 is a large sum, the cost per ton is about 0.1168 cents. Credit for this goes

Jan 1, 1947