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By V. N. Burnhart

After eight years of testing and development, the E. J. Longyear Co. has adapted the wire- line core barrel to small diameter drillholes. Field performance indicates that the apparatus for the BX hole will be an important supplement to the conventional techniques used in the diamond core drilling industry. Higher core recovery, faster drilling progress, and reduced diamond costs will provide substantial savings to the user of coring equipment. The wire-line principle is not new, having been successfully applied to the large-diameter holes of the petroleum industry. But scaling the practices of core recovery in oil well drilling down to the small BX hole presented a number of problems. The technique, difficult even for large holes, was complicated by the exacting limitations of the small diameter in which durable and foolproof mechanisms would be required to operate. Since the maximum benefits could be realized from this sys- tem in holes 1000 ft and deeper or in holes in badly fractured ground, the drill string would have to be able to withstand heavy stresses. Most vital to the success of the idea was the development of a positive latching mechanism to assure proper positioning of the inner tube of the core barrel when the tube is dropped into place. Lastly, little was to be gained from the wire-line method without diamond bits that would give optimum penetration rates and a long service life in the drillhole.

Jun 1, 1955

By F. M. Lewis, J. F. Meyers

This second progress report of grinding presents comments regarding ball consumption and data pertaining to the hydroscillator, which is closed circuited with the tricone mill. A study and postulate of how balls function is presented. The paper summarizes cost reduction obtained by the method of "grinding for the tail race" rather than for "mesh tons." AT the Regional meeting in Columbus, Ohio, in September 1949, the authors presented a progress report of the first year's operation with a Hardinge tricone mill in closed circuit with a Dorr hydroscillator. The present report covers our findings on this grinding circuit to January, 1950. In order to clarify our position, the authors wish to state that no invention or discovery is claimed. The Tennessee grinding circuit is simply an engineered arrangement of known equipment arranged to incorporate all of the recognized efficiency factors of comminution as they are known today. As we concluded our first report, it was not clear how effective the Tennessee mode of operation would be on harder ores. The only information we had at that time was that the Bond grindability test at 48-mesh gave 6.04 g of undersize per revolution. A later test on the same sample at 100-mesh reduced this to 2.04 g, which is definitely in the harder ore class, and which makes the reported 8.80 kw-hr per ton of —200-mesh produced a very creditable figure. Hydroscillator Operation The machine as now developed has proved dependable and easy to operate. It starts easily under full load and responds quickly to operating adjustments. The hydraulic holes in the oscillating plate do not plug when shut down under full load. Absolutely clean hydraulic water is essential. An Elliott water screen or similar device should be an essential part of the machine to keep all scale and trash of all kinds from the hydraulic compartment. The shift operators have expressed approval of the machine. In table I we show a typical screen analysis of the hydroscillator rake sand as compared to conventional classifier rake sand on our ore. We have previously reported that of the 28.7 pct reduction in power, the hydroscillator contributed 6 pct, on a —200-mesh basis. This is a conservative figure. Some of our test runs indicated that the saving was as high as 10 pct. Laboratory studies by the Dorr Co. engineers indicate that still greater efficiency is possible. Nevertheless, the 10-ft plate is overflowing 2100 tons per day at 3 to 4 pct + 65-mesh, which is a very creditable performance by

Jan 1, 1951

By F. M. Lewis, J. F. Meyers

This second progress report of grinding presents comments regarding ball consumption and data pertaining to the hydroscillator, which is closed circuited with the tricone mill. A study and postulate of how balls function is presented. The paper summarizes cost reduction obtained by the method of "grinding for the tail race" rather than for "mesh tons." AT the Regional meeting in Columbus, Ohio, in September 1949, the authors presented a progress report of the first year's operation with a Hardinge tricone mill in closed circuit with a Dorr hydroscillator. The present report covers our findings on this grinding circuit to January, 1950. In order to clarify our position, the authors wish to state that no invention or discovery is claimed. The Tennessee grinding circuit is simply an engineered arrangement of known equipment arranged to incorporate all of the recognized efficiency factors of comminution as they are known today. As we concluded our first report, it was not clear how effective the Tennessee mode of operation would be on harder ores. The only information we had at that time was that the Bond grindability test at 48-mesh gave 6.04 g of undersize per revolution. A later test on the same sample at 100-mesh reduced this to 2.04 g, which is definitely in the harder ore class, and which makes the reported 8.80 kw-hr per ton of —200-mesh produced a very creditable figure. Hydroscillator Operation The machine as now developed has proved dependable and easy to operate. It starts easily under full load and responds quickly to operating adjustments. The hydraulic holes in the oscillating plate do not plug when shut down under full load. Absolutely clean hydraulic water is essential. An Elliott water screen or similar device should be an essential part of the machine to keep all scale and trash of all kinds from the hydraulic compartment. The shift operators have expressed approval of the machine. In table I we show a typical screen analysis of the hydroscillator rake sand as compared to conventional classifier rake sand on our ore. We have previously reported that of the 28.7 pct reduction in power, the hydroscillator contributed 6 pct, on a —200-mesh basis. This is a conservative figure. Some of our test runs indicated that the saving was as high as 10 pct. Laboratory studies by the Dorr Co. engineers indicate that still greater efficiency is possible. Nevertheless, the 10-ft plate is overflowing 2100 tons per day at 3 to 4 pct + 65-mesh, which is a very creditable performance by

Jan 1, 1951

PUGET SOUND SECTION SIMON H. ASH, Chairman, I. F. LAUCKS, Vice Chairman, CHARLES SIMENSTAD, Sec.-Treas., 425 Lyon Building, Seattle, Wash. GLENVILLE A. COLLINS, JOHN N. POTT. The Puget Sound Section met at the Arctic Club, Seattle, Wash., on Jan. 20, 1917. Sixteen members and five guests were present. Dinner having been served, the meeting was called to order. A letter from secretary of Associated Engineering Societies was read, requesting payment of this section's assessment to the quarterly budget, and upon motion it was voted that the Secretary-Treasurer be instructed to pay this assessment. It was moved and carried that this section join with the Chemical Society in a meeting. At the, close of the business meeting, Mr. Asa C. Baldwin gave an illustrated lecture on the "Alaska Boundary Survey." On Feb. 24, the Puget Sound Section again held a meeting at the Arctic Club, 16 members and three guests being present. Chester F. Lee, as member of a committee representing this section in the joint council of the Associated Engineering Societies, reported that by lots it had been decided that the term of service of said committee would be as follows: Chester F. Lee, two years; George. Watkin Evans, one year. Following adjournment of the business meeting, Prof. Joseph Daniels, of the University of Washington, delivered a very interesting lecture on "Milling Practice of The Alaska-Castineau Mining Company." CHAS. SIMENSTAD, Secretary.

Jan 5, 1917

By G. F. Jenkins

The word asbestos is a broad term that has been accepted and applied to a number of fibrous mineral silicates found in nature. They are incombustible and can be separated by mechanical means into fibers of various lengths and thicknesses, but differ in chemical composition and other properties. It is generally recognized that there are six varieties of asbestos; the finely fibrous form of serpentine known as chrysotile, and five minerals of the amphibole group, i.e., amosite (not fully recognized as a mineral species name but accepted in asbestos terminology), anthophyllite, crocidolite, tremolite and actinolite. (Figs 1-4.) Physical and Other Properties The structures of asbestos fibers have been studied intensely in recent years. X-ray diffraction patterns 1 to 15 have been used as a means of identification and classification. The amphibole group structures have been fairly well established while the serpentine group has been the subject of many investigations during the past six years. Low-angle X-ray scattering techniques5 have shown that the chrysotile fibrils are "hexagonally close packed" and parallel to each other, having cross-sectional diameters varying from 180Å* units to 300Å units, while the amphibole fibers are many times larger in cross section. The electron micrographs of chrysotile asbestos (Figs 1-4) have also indicated that the fibrils might be in the form of a hollow tube. This point has been the subject of considerable controversy by a number of investigators.7 to 16 Density measurements17 made on a sample of high quality Arizona fiber did not indicate that the fiber had a hollow tube structure; however, the so-called "sheet structure" of the fibril could be distorted in such a way that it gives the appearance of a hollow tube in the electron microscope. It is of interest to quote one investigator, F. L. Pundsack,17 in this connection: Although the empirical composition of chrysotile is 3MgO.2SiO2.2H20, the true unit cell[#] composition is best represented as Mg12(OH)16Si8O20. This cell has dimensions of a= 5.3Å, b = 9.2 Å, and c = 14.6 Å where the "a" direction is the fiber axis. The calculated density of this unit is 2.56 g/cc, a value in close agreement with experimentally determined density values for chrysotile. The exact manner in which the unit cells of asbestos are stacked together to build up a single fiber of chrysotile is not known, but from various

Jan 1, 1960

By G. Willard Quick

FAILURES in railroad rails have been of vital concern to engineers; railroad executives, rail manufacturers and the general public for years. Failures from transverse fissures originating from internal nuclei have received particular attention in the past 20 years. Dr. J. E. Howard first reported this type of failure in 1911, as being responsible for a wreck-on the Lehigh Valley R. R. in which several lives were lost. Since then many transverse fissures have been found. In 1919, Waring and Hofammann1 etched longitudinal sections of rails in hot acid and found cracks extending both longitudinally and transversely in certain used rails as well as in some new rails.. Since then it has been thought by many that these "shatter" cracks are the nuclei from which transverse fissures subsequently develop in service. Methods for reducing the rate of cooling rails on the hot. bed have been devised to decrease the temperature gradient and consequently the stress gradient in the rails. A study of the tensile properties of rails at elevated temperatures was made by Freeman and Quick,2 who investigated the properties at temperatures through which rails pass on the cooling bed after leaving the hot saw. In their investigation a special study was made of the ductility of the steels in the temperature range 400° to 700° C. In this temperature range it was found that certain rail and other steels showed a marked decrease in elongation and reduction of area. The phenomenon was called "secondary brittleness" and the temperature range the "secondary brittle range." A tentative explanation was presented that internal failure such as "shatter cracks" and "hair cracks" in rails are the result of thermal stresses developed in the steel structure while cooling through the secondary brittle range. The investigation showed that the magnitude of the phenomenon varies for different heats, but that it did not differ for specimens from different ingots or for different rails in a particular ingot. It was also shown that annealing rail steel at a temperature either above or below the critical

Jan 1, 1932

By Henry S. Rawdon

The relation between the course, or path, of the fracture of metals and alloys, produced in service or as a result of certain laboratory tests, and the crystalline units of which such materials are composed is of utmost importance. The fracture of normal material is, in general, intracrystalline, i.e., it consists of a break across the grains rather than of a separation between them. An interorystalline fracture indicates either that the metal is of very inferior quality or that the break occurred under very unusual conditions, e.g., at a very high temperature. The usual mechanical tests, when applied to metals of the type that breaks with an intercrystalline fracture, merely measure the coherence of adjacent grains for one another and reveal little as to the real properties of the metal itself. Even such a soft plastic substance as lead, under suitable conditions, may be rendered so weak and brittle that the metal can be easily crumbled into powder by the fingers although the constituent grains have lost none of the intrinsic properties of lead. Various erroneous explanations of this behavior of lead have appeared in the scientific literature, the change being described usually as an allotropic one. The importance, in an industrial sense, of a proper explanation of this type of the corrosion of lead justifies the description of the type of metal deterioration that follows. Corroded Lead Sheathing In Figs. 1 and 2 are shown two typical specimens of corroded lead sheathing selected from materials submitted to the Bureau of Standards for examination. Fig; 1 shows a section of the sheathing of an aerial cable; Fig. 2, that of the lead covering of a subterranean feeder-line of an electric light system. In this case the deterioration had proceeded to a much great'er extent than in the case shown in Fig. 1 so that certain portions of the metal could easily be crumbled into a coarse gray powder by the fingers. This was particularly true of those portions of the sheathing

Jan 1, 1921

By H. E. Hostetter

Grossmann's method1 for calculating the hardenability of steel from the composition and grain size has gained wide acceptance, and when properly used, has been well proved in practical application, both for estimating the hardenability of known compositions and for selecting compositions to meet known hardenability requirements. The Grossmann method uses as the criterion of hardenadility the "ideal critical diameter," DI, which is the' size round that will just harden to a structure of 50 per cent martensite at the center when given the theoretically fastest quench, or "ideal quench." The DI can be related to actual quenching practice if the severity of quench is known; or the DI can be correlated with hardenability as determined by the Jominy end-quench method.2 The effect on hardenability of each element present in a steel can be represented by a multiplying factor, the value of which depends on the amount of the element present and the degree of effectiveness of the particular element. (The value of the factor for a given carbon content varies with the grain size.) When the factors for all elements present in a steel have been determined from charts, they are multiplied, and the resultant product is the DI of the steel. The validity of Grossmann's scheme of multiplying factors has been confirmed in a number of other investigations.3-6 It can be appreciated that a certain desired level of hardenability can be obtained by adding chromium, molybdenum, nickel and vanadium to a base composition containing carbon, manganese, silicon and the usual impurities. Many of the ranges of hardenability used commercially can be obtained by any of the foregoing alloying elements used singly in the base composition. The same hardenability levels also can be obtained through use of any of a great number of multiple element combinations of these alloying elements. In this report a method will be presented for determining what one combination is the most efficient (based on hardenability and cost of added alloy) for a given level of hardenability. It should not be assumed from the emphasis given to hardenability, that hardenability is the only criterion for the selection of an alloy composition. Such properties as the hot-working characteristics, machinability, carburizing characteristics, amount of distortion during quenching and the retention of austenite may be considerations of importance in many applications. However, hardenability is one of the most important properties of an alloy steel and one that must be considered in almost all cases involving heat-treatment by quenching. Therefore, a method for determining the lowest-cost alloy combination should be of considerable value. Determination of Most Efficient Combinations For comparing the alloying elements on standards of cost and hardenability, it

Jan 1, 1947

By H. E. Hostetter

Grossmann's method1 for calculating the hardenability of steel from the composition and grain size has gained wide acceptance, and when properly used, has been well proved in practical application, both for estimating the hardenability of known compositions and for selecting compositions to meet known hardenability requirements. The Grossmann method uses as the criterion of hardenadility the "ideal critical diameter," DI, which is the' size round that will just harden to a structure of 50 per cent martensite at the center when given the theoretically fastest quench, or "ideal quench." The DI can be related to actual quenching practice if the severity of quench is known; or the DI can be correlated with hardenability as determined by the Jominy end-quench method.2 The effect on hardenability of each element present in a steel can be represented by a multiplying factor, the value of which depends on the amount of the element present and the degree of effectiveness of the particular element. (The value of the factor for a given carbon content varies with the grain size.) When the factors for all elements present in a steel have been determined from charts, they are multiplied, and the resultant product is the DI of the steel. The validity of Grossmann's scheme of multiplying factors has been confirmed in a number of other investigations.3-6 It can be appreciated that a certain desired level of hardenability can be obtained by adding chromium, molybdenum, nickel and vanadium to a base composition containing carbon, manganese, silicon and the usual impurities. Many of the ranges of hardenability used commercially can be obtained by any of the foregoing alloying elements used singly in the base composition. The same hardenability levels also can be obtained through use of any of a great number of multiple element combinations of these alloying elements. In this report a method will be presented for determining what one combination is the most efficient (based on hardenability and cost of added alloy) for a given level of hardenability. It should not be assumed from the emphasis given to hardenability, that hardenability is the only criterion for the selection of an alloy composition. Such properties as the hot-working characteristics, machinability, carburizing characteristics, amount of distortion during quenching and the retention of austenite may be considerations of importance in many applications. However, hardenability is one of the most important properties of an alloy steel and one that must be considered in almost all cases involving heat-treatment by quenching. Therefore, a method for determining the lowest-cost alloy combination should be of considerable value. Determination of Most Efficient Combinations For comparing the alloying elements on standards of cost and hardenability, it

Jan 1, 1947

By AIME AIME

WEST TEXAS, New Mexico and Northern Mexico form one of the most interesting regions in America for geologists and mining men and are full of points of historical and human interest for others. Including as the region does, a representative portion of the high plateau of Mexico, the front range of the Rocky Mountains and the great down-dropping plains of Texas, there is variety as well as interest in the geological and mining problems there to be studied. Gold and silver mining were the pioneer industries and are yet of high rank in importance. Among the papers to be presented at the El Paso meeting of the Institute this month will be two dealing with silver mining and ore treatment at the Shafter mine in Texas, that most un- usual property which has for so many years been the largest mining enterprise in its region. West Texas is now better known for its petroleum and gas, and in another paper will be described the problems involved in uding natural gas for smelting at the well-known El Paso smelter of the American Smelting and Refining Co. In still other papers, presented at the session sponsored by the West Texas Geological Society and cooperating organizations, the general geology of the region, the potash and the sulfur deposits will be de- scribed. At El Paso the refineries of the great com- panics will be available for visits.

Jan 1, 1930

By C. Norman Bowers, Blaine B. Wescott

Marked improvement in the serviceability of sucker rods has been effected in the last two years, partly because of the insistent necessity for greater economy in the operating costs of crude oil production growing out of the general industrial depression and partly because many of the recently developed fields have imposed more severe operating conditions upon both surface and underground equipment. The latter is particularly true of Kansas, where practically all of the oil produced is associated with damaging amounts of hydrogen sulfide brine and where the method of establishing potential production demands equipment capable of being operated at maximum capacity without interruptions. The decline of flush production in the Oklahoma City field created new problems in deep-well pumping on a scale heretofore unequaled and the increased proportion of water it has been necessary to produce in the fields of the Greater Seminole area presented conditions that were acutely in need of betterment. The problem in the latter fields was complicated by the shift towards sulfide characteristics, which accompanied water encroachment, and it is probably true that nowhere, at the present time, are pumping conditions generally as severe as in this territory. The Mid-Continent district, therefore, has become the proving ground for the numerous materials that have been proposed for sucker-rod fabrication. The information that ultimately will be obtained from an unprecedented amount of field experimentation will pay ample dividends when the decline of East Texas increases the demand for the vast reserves of sour crude in West Texas. It is a rare occurrence in industry that the use of such a simple piece of equipment as a sucker rod presents so complicated a problem for solution. As proof of this, it is only necessary to consider the numerous types of sucker rods on the market at the present time and contrast this condition with that of less than four years ago, when it was the common aim of manufacturers to develop a single sucker rod for all conditions of

Jan 1, 1935

By C. D. Ramsden

During the war years of 1941 to 1945, maintenance of mine locomotives and other mine equipment took the form of rebuilding rather than of renewing. Purchase of new parts became increasingly difficult and mine operators found it necessary to maintain equipment by salvaging old parts. Mine-locomotive wheels, although not representing a high cost per pound of material, contain a considerable amount of steel and without rebuilding would have to be scrapped long before even a moderate percentage of the steel in the wheel is actually consumed. Many mine operators have been rebuilding locomotive wheels for several years with automatic open are-welding equipment. In 1927, the Pittsburgh Coal Co. started such a program, using a single Westinghouse automatic welding head. Since that time, many refinements have been added, until in 1944 the setup was operating very efficiently. A desire to increase wheel life and to hold down rising costs led the company in 1944 to investigate the possibilities of the under-flux are-welding process for wheel rebuilding, although at that time, little or no work had been done on multiple pass or "build-up" welding with the underflux arc. Work with this process had been confined largely to welding together flat plates in a "down hand" position. Possibilities for savings were intensified by the fact that the company has 300 locomotives in operation, using actively or as spares 1200 sets of wheels. During 1942 and 1943, about 500 sets of wheels were sent each year to the company's maintenance shop at Library, Pa., for rebuilding. Based on having 800 sets in service (many of the company's heavy locomotives have three sets of trucks), the average life of a set of wheels was approximately 19 months. Anything that could be done to increase wheel life promised sizable annual savings. Open Arc Welding With the open arc process, a set of wheels could be rebuilt for about 40 pet of the cost' of new wheels. Underflux arc welding gave promise of greatly increased welding speeds, more homogeneous, dense deposits and the chance for use of a wider range in welding-wire compositions. Against this was ranged the higher cost of materials and the cost of developing the process from the theory to a practical reality. Since 1927, when a single open arc head was placed in operation, fixed welding procedures had been gradually developed, a positioner for handling a set of wheels was built, and a second head was placed in operation in order to weld two wheels simultaneously. The fixture, or positioner, which was built to position and turn the wheels under the two welding heads, included a motor drive, controlled by a rheostat, which rotated the wheels through a double set of speed reducers and a removable jaw coupling attached to one end of the axle of the wheel truck.

Jan 1, 1947

By C. D. Ramsden

During the war years of 1941 to 1945, maintenance of mine locomotives and other mine equipment took the form of rebuilding rather than of renewing. Purchase of new parts became increasingly difficult and mine operators found it necessary to maintain equipment by salvaging old parts. Mine-locomotive wheels, although not representing a high cost per pound of material, contain a considerable amount of steel and without rebuilding would have to be scrapped long before even a moderate percentage of the steel in the wheel is actually consumed. Many mine operators have been rebuilding locomotive wheels for several years with automatic open are-welding equipment. In 1927, the Pittsburgh Coal Co. started such a program, using a single Westinghouse automatic welding head. Since that time, many refinements have been added, until in 1944 the setup was operating very efficiently. A desire to increase wheel life and to hold down rising costs led the company in 1944 to investigate the possibilities of the under-flux are-welding process for wheel rebuilding, although at that time, little or no work had been done on multiple pass or "build-up" welding with the underflux arc. Work with this process had been confined largely to welding together flat plates in a "down hand" position. Possibilities for savings were intensified by the fact that the company has 300 locomotives in operation, using actively or as spares 1200 sets of wheels. During 1942 and 1943, about 500 sets of wheels were sent each year to the company's maintenance shop at Library, Pa., for rebuilding. Based on having 800 sets in service (many of the company's heavy locomotives have three sets of trucks), the average life of a set of wheels was approximately 19 months. Anything that could be done to increase wheel life promised sizable annual savings. Open Arc Welding With the open arc process, a set of wheels could be rebuilt for about 40 pet of the cost' of new wheels. Underflux arc welding gave promise of greatly increased welding speeds, more homogeneous, dense deposits and the chance for use of a wider range in welding-wire compositions. Against this was ranged the higher cost of materials and the cost of developing the process from the theory to a practical reality. Since 1927, when a single open arc head was placed in operation, fixed welding procedures had been gradually developed, a positioner for handling a set of wheels was built, and a second head was placed in operation in order to weld two wheels simultaneously. The fixture, or positioner, which was built to position and turn the wheels under the two welding heads, included a motor drive, controlled by a rheostat, which rotated the wheels through a double set of speed reducers and a removable jaw coupling attached to one end of the axle of the wheel truck.

Jan 1, 1947

By John C. Bilello

The brittle fracture behavior of cold-worked sintered tungsten was studied over the temperature range 4.2° to 298°K using a high-sensitivity strain measuring system and electronfractography. Similar observations were made on a swaged electron beam zone-refined monocrystal. In sintered tungsten irreversible plastic deformation was observed during cyclic load-unload tests at stress levels well below the fracture stress for all temperatures, but general microyielding could be detected only down to 202°K. For the zone-refined samples macroyielding occurred at all test temperatures with evidence for twinning below -202°K. The fracture stress of the sintered tmgsten was virtually independent of temperature, while the zone-refined crystal showed a 2.3 times increase over the same temperature range. Electronfractography confirmed the presence of numerous rod-shaped and spherical submicroscopic voids which ranged in diameter from 1400 to 4300A in the sintered tungsten; no voids could be found in the zone-refined tungsten. Contrast effects observed on the replicas in the vicinity of certain voids indicated that plastic deformation could be induced by the local stress concentration. It has been suggested that the presence of these voids may be responsible for the low-temperature brittle failure of sintered tungsten. Based m this suggestim und on the evidence obtained here, a dislocatim model is presented to account for the brittle behavior of sintered tungsten. In this model slip, which is induced by the local high stress concentration in the region at the edge of a favorably oriented void, could cause the void to grow to a microcrack of critical size. STUDIES of brittle fracture in bcc metals have led to the well-known experimental relationships between grain size, yield stress, fracture stress, and temperature which have formed the basis for the various dislocation pile-up1-3 or interaction4'= models for slip-induced microcrack nucleation. While microcracks can be nucleated by deformation twins,6,7 there has been no direct evidence furnished by transmission electron microscopy to support conclusively either the Zener pile-up or Cottrell dislocation reaction models for producing micro-cracks in all "brittle" materials. In addition to the "inverse" grain size relationship for yield and fracture stresses the cottrel14 theory predicts that the fracture stress below the transition temperature should behave in a fashion similar to that of the yield stress above this temperature. Such behavior has been verified for several bcc metals.8-10 With reference to both grain size effects and the tem- perature dependence of the fracture stress below the transition temperature, the behavior of sintered tungsten appears anomalous. Early work by Bechtold and Shewrnon 11 showed no apparent temperature dependence of the fracture stress below the ductile-brittle transition temperature (DBTT). They attributed this result to the intergranular nature of the fractures observed. More recent work by Wronski and Four-deux12'13 on considerably purer material did not show any systematic relationship between the fracture stress and temperature below DBTT. The dependence of flow and fracture stresses on grain size is also not clearly established for sintered tungsten. Koo, for example, has shown that the DBTT for sintered tungsten depended chiefly on the annealing temperature and was relatively insensitive to the actual grain size achieved. Using electrofractography and transmission electron microscopy, Wronski and Fourdeuxl3 showed that numerous spherical and rod-shaped submicroscopic voids could be found in sintered tungsten but not in melted tungsten of nominally the same purity. They suggested that these voids could be responsible for the temperature insensitivity of the fracture stress below the DBTT. In the present work the temperature dependence of the fracture stress for high-purity commercially sintered tungsten has been determined. The presence of submicroscopic voids in sintered materials was confirmed, and these were studied in detail to examine the role they could play in nucleating brittle fracture. A dislocation model is suggested which could cause an inherent spherical void to lengthen into a Griffith crack of critical size. EXPERIMENTAL PROCEDURE Commercially sintered tungsten rod was obtained in the as-swaged condition from Sylvania. A zone-refined crystal was obtained from the same source. This crystal was grown by giving three zone passes (at 25.4 cm per hr) to a sintered rod of high-purity tungsten. The rod axis prior to cold working was -15 deg from the [110] direction. Originally the zone-refined rod was -6 mm in diam; it was reduced to -3 mm by eight swaging passes, at high temperatures, with each step having about the same reduction of area. The final swaging step gave a 7.5 pct reduction of area at 1050°C. All swaging operations were performed in a hydrogen atmosphere. For the sintered rod a similar working schedule was employed. Metal-lographic examination of the sintered material revealed that the cold-worked structure had an apparent grain diameter of -25 u transverse to the swaging direction (obtained by the intercept method). In the longitudinal direction cold-worked grains were approximately 1.5 to 2 times their diameter. No distinct fiber structure could be observed optically for the zone-refined rod. The cold-worked structure in the

Jan 1, 1969

By Albert L. Toenges

Alaska requires an adequate fuel supply for its development, and has large potential coal reserves ranging from lignite to subbituminous and anthracite. Coal production in the Territory now is less than the requirements. In L947, production was 361,000 tons, divided about equally between bituminous coal from the Matanuska field and subbituminous coal from the Nenana field. There is need for development of modern mechanized mines, which should produce the required output with a minimum of workers. These mines should not be thought of in the light of large potential capacity, as in the States. However, these new mines should be developed by modern methods, which should result in lower costs than at Present. Because of the diverse physical conditions in the coal fields, intensive investigation by diamond drilling is necessary to properly plan the development and equipment of mine sites at minimum cost. The Bureau of Mines is doing this now in the Wishbone Hill area of the Matanuska field. All coal land in Alaska is government-owned and subject to the Coal Leasing Act. Coal mining in Alaska has been handicapped by an inadequate supply of dependable workers. Wage scales have been very high in recent years, and "floaters" have been attracted to the coal mines. This type of labor is not conducive to efficient operation. Modernization of mines will require skilled and dependable workers and to induce such men to become interested in coal mining in Alaska, modern facilities, such as modern houses, schools, churches, and recreation halls, must be provided near the mines. Alaska is still a frontier and improvements in living standards must accompany development of mines in order that a stable community may be established. Coal is known to have been mined in Alaska at Port Graham, on Cook Inlet, by the Russians in 1854. During the Klondike gold rush in 1898, coal was mined in scattered areas for use on steamers plying the Yukon River and its navigable tributaries. After the Alaska Railroad was built, two important fields were developed—the Nenana and the Matanuska (Fig 1). The Bering River field was explored by the Guggenheim interests at one time, and a railroad to the area was constructed. However, the field was abandoned because of litigation and reported unsatisfactory physical condition of the beds. There are areas that today are unimportant but which may be developed in the future. Possibly the most important of these is the deposits of subbituminous coal adjacent to Cook Inlet, near Homer, on the Kenai Peninsula (see Fig 1). It is expected that the demand for coal in the Kenai Peninsula will increase because the population in that area has increased as a result of agricultural development. Numerous outcrops of coal are exposed on the peninsula and development of a mine there would obviate dependence on supplies of coal from the Matanuska field. Coal from this field must be shipped approximately 160 miles by rail to Seward and transported thence by boat about 180 miles to Homer. There has been no regular boat service from Anchorage to Homer. There are deposits of coal in the Arctic region but a description of them will not be given in this paper, which will describe the more important deposits in the Alaska Railroad belt. The results of a reconnaissance in the Arctic have been described.' Description of Fields MATANUSKA FIELD The Matanuska field lies in the valleys of the Matanuska River and its tributaries and their separating ridges. This field has been interpreted by geologists as a sunken fault block that separated the Talkeetna Range of mountains from the Chugach Range. The Matanuska River flows west along the south side of the field and the Glenn highway, which extends from Anchorage via Palmer to the Richardson highway near Glen Allan, follows the Matanuska Valley. This road to the coal field can be traveled the year around. Although the snow-

Jan 1, 1950

Gentlemen.-It is pleasant to be able to report that the year just closed has been a prosperous and successful one for the Institute. As is shown by the reports of the Treasurer and the Finance Committee, the business affairs of this organization are in excellent condition. With property valued at more than three-quarters of a million dollars, and with considerable sums in various funds and endowments, it is possible to spend on each member of whatever class $22.65 each year, more than the maxi- mum amount of dues received from any one, and substantially twice the average amount, $10.94, received from all. To do this has required close management and a strict regard for our limitations. In 1926, when the Budget was made up, the estimated expenditures for the work which it was felt the Institute must do exceeded the estimated receipts by some $14,000. At the close of the year, despite a number of unexpected decreases in receipts, it had proved possible to accomplish substantially all the work laid out and close the books with the usual transfer of initiation fees to the General Reserve, and still only reduce the cash balance $2,074.54. This was made possible by the hearty and loyal cooperation of the whole staff of employees and the extremely large amount of gratuitous service rendered by the officers, the members of the Divisions and technical Committees, and the membership generally. Even so it was impossible, because of limitations of funds, to undertake many things it is highly desirable for the Institute to do, and it was necessary to refuse the publication of important papers and committee studies, because of the lack of funds. PUBLICATIONS In an analysis of the income and expenses of the Institute published in the February issue of our Journal, MINING AND METALLURGY, it was pointed out that the largest item of expenditure is, as it should -be, for publications. Printing, binding, and distributing the various technical papers sent to the members cost in 1926 more than all the money received from dues, including the portion allocated as subscription to the magazine. Within the. year, the following volumes were printed and, with the exception of the second volume of TRANSACTIONS, which was mailed in January, were distributed : TRANSACTIONS, Volume 73, 1241 pages, covering papers on non-ferrous metallurgy, milling and concentration, non-metallic minerals, iron and steel, and the Institute of Metals Division papers read at the

Jan 1, 1928

By R. H. Frazier, C. H. Lorig, F. W. Boulger

This investigation establishes the effect of ferrite grain size resulting from various heat treatments on the transition temperature of a semikilled steel plate. Different austenitizing temperatures and various cooling rates were used. The ductile-brittle transition temperatures were determined by the Navy tear test and the keyhole Charpy test. THE data presented in this paper deal with quality characteristics of ship-plate material which were investigated in a research project sponsored at Battelle by the Bureau of Ships, Dept. of the Navy. Specifically, the object of this investigation was to establish the effect of ferritic grain size (resulting from various heat treatments) on the so-called transition temperature of ship-plate steel. Transition temperature is not a fixed property of steel. It is derived from a series of static or dynamic tests made at various temperatures and is qualified by specifying the type of test employed as well as the testing criteria. Because in earlier investigations of ship-plate quality1,2 the so-called Navy tear test and standard notched-bar tests (keyhole Charpy) proved to be useful in interpreting instances of brittle behavior of ship plate in service, these tests were used in the investigation reported in this paper. By definition,' in the Navy tear tests the highest temperature at which one or more of four specimens breaks with a brittle fracture (that is, when less than 50 pct of the fracture area has a dull fibrous texture) is termed "transition" temperature. In the Charpy tests, the 12 ft-lb level of energy absorption was used as a criterion indicating the "transition" temperature, although other levels of energy absorption were also used for comparison. Earlier work" on ship-plate steels indicated that the temperature at which ship plate is finished has a very significant effect on its notched-bar properties. Plates rolled in the laboratory, where the finishing temperature can be carefully controlled, showed a 16°F decrease in tear test transition temperature when the finishing temperature was lowered 200°F (from X" to Y°F). The same plates showed a drop of 10°F in the keyhole Charpy transition temperature from the same decrease in finishing temperature. Commercially finished plates' exhibit a similar trend. When the ferrite grain size of the hot-rolled laboratory plates was determined, a close relationship was found between the ferrite grain size and the notched-bar transition temperature." " he indicated relationship between grain size and transition temperature was in agreement with the findings on low carbon steels of Hodge, Manning, and Reichhold' despite the differences in composition of the steels. The cooling rate after rolling varies from one steel plant to another. This variation changes the micro-structure" and appears very likely to affect the notched-bar properties of the steel plates. In the investigation summarized in the present paper, heat treatments simulating finishing practices in the hot rolling of ship plate were used in order to vary the ferritic grain size. It is believed that the indicated relationship between grain size and transition temperatures of the ship-plate material will prove useful in estimating the effect of rolling temperature and of cooling rates from rolling temperatures on the notched-bar properties of semikilled steel plate. Material The semikilled steel plate used in this investigation was a ¾ in. hot-rolled plate from an open hearth heat. Other plates from this heat have been used on many other studies performed for the Ship Structure Committee," "," and the heat has been identified as project steel "A". The chemical composition of the plate1 was 0.25 pct C, 0.49 pct Mn, 0.011 pct P, 0.045 pct S, 0.04 pct Si, and 0.004 pct N.

Jan 1, 1956

By Geo. H. Ashley

THE present critical state of the supply, distribution, and utilization. of coal and the necessity for pooling and zoning coals calls renewed attention to the lack of any fully adequate classification of coal. In the past coals have been classified as anthracite, semianthracite, semibituminous, bituminous, subbituminous coals, and lignite, and a few special types, such as splint coal and cannel coal. But under the term bitumi¬nous coal are included a great variety of coals differing markedly both physically and chemically. The term subbituminous coal covers as great a range of chemical differences. In order to distinguish these varieties of bituminous coals it has been customary to designate coals by names derived from the place where mined, or by the name of the bed from which it is mined. Thus, in the market reports, coals are quoted as Pocahontas coal, New River or Sewell coal, Moshannon coal, Ohio coal, Williamson County coal, Jellico coal, and so on indefinitely, no limit being set as to the boundaries of the area to which a given name is applied. Nor is there any scale by, which the coal from one place may be compared with the coal from some other district or some other bed. On the one hand, coals from the same district may be quite distinct and sell at very different prices or coal from the same bed may differ greatly in different districts; on the other hand, coals from different states may be so similar physically and chemically that one could replace the other in practical use without any appreciable difference in service.

Jan 8, 1919

By Mack H. Shumate

1 Raw coal from Truax-Traer Coal Co.'s Burning Star Slope mine, Jackson County, Ill., is brought to the surface by the new 42-in. slope belt haulage conveyor at the rate of 850 tph. The loading system shown above employs four storage tracks, two tail tracks for loading, and four 25-hp hoists, operating in pairs, and coupled to two dolly cars to move the trains of cars through the tipple. The system has a capacity for loading 1800 tph. One operator is needed to load on each of two shifts. A third man working for a few hours on night shift sets up for the morning cycle. Railroad crews bring in empties placing them in the storage yard, twenty cars to the track. Trains of empties are pulled through to the tail track and loaded on the return; hoists at opposite ends pull the trains in each direction. [ ] 2 Pairs of hoist drums are interconnected electric- ally by a Trench lay cable buried between the tracks. When one hoist operates moving the cars, the tail hoist idles with brake released. The operator, situated in the tipple over the cars, views the storage yard at the end of the first shift (left). When returning loaded cars to yard, four or five cars are held on the dolly to couple the next string of empties. Empties are ready for loading on the tail track (right). Differing from a gravity system in which empty and load tracks are on a slight grade, this system is designed for 80 railroad cars for a two-shift operation and one rail service per day.

Jan 6, 1962

By Alfred Brooks

Introduction PETROLEUM seepages are known in Alaska at four localities, all on Pacific seaboard. These, named from east to west, are Yakataga, Katalla on Controller Bay, Iniskin Bay on Cook Inlet, and Cold Bay on the Alaska Peninsula. Besides these, a petroleum residue has been found near Smith Bay on the north Arctic coast of the Territory. At Katalla, Cold Bay, and Iniskin Bay there has been some drilling for oil, and in the first field several productive wells have been opened up. Alaskan petroleum so far as its composition is known, is a refining oil, with paraffin base and low sulphur content. Most of what is known of the geology of Alaska oil fields is based on the investigations of Dr. George C. Martin, of the United States Geological Survey. A. G. Maddren, of the same service, has recently made a reconnaissance of the Yakataga oil field. The data to be here presented are chiefly taken from the following publications: G. C. Martin: The Petroleum Fields of the. Pacific Coast of Alaska, with an account of the Bering River coal deposits, Bulletin No. 250, U. S. Geological Survey, pp. 9 to 27 (1905). G. C. Martin: Geology and Mineral Resources of the Controller Bay Region, Alaska, Bulletin No. 335, U. S. Geological Survey, pp. 112 to 130 (1908). G. C. Martin and F. J. Katz: A Geologic Reconnaissance of the Iliamna Region, Alaska, Bulletin No. 485, U. S. Geological. Survey, pp. 126 to 130 (1912). A. G. Maddren: Mineral Deposits of the Yakataga District, Bulletin No. 592,. U. S. Geological Survey, pp. 143 to 147 (1914).

Jan 2, 1915