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By C. B. Jordan

LAVES and Wallbaum' have described TiRu and TiOs as having the same structure as TiFe; they had previously described the latter compound as having the CsCl structure. On the other hand, a careful investigation of the structure of TiFe by Duwez and Taylor- ailed to reveal the ordered CsCl structure, finding instead a random arrangement of titanium and iron atoms on the points of a body-centered-cubic space lattice. Consequently, it is not clear whether Laves and Wallbaum proposed the ordered or the disordered structure for TiRu and TiOs. In order to settle this question as to the structural type and to obtain values of the lattice para- meters (thereby completely determining the structures), the present investigation was undertaken. Samples having the compositions TiRu and TiOs were weighed out accurately from iodide titanium supplied by the New Jersey Zinc Co., ruthenium powder from Goldsmith Brothers Smelting & Refining Co., and osmium powder from Wildberg Brothers Smelting & Refining Co. No analysis was made of any of these metals. According to the respective analyses of the suppliers, total impurities amount to less than 0.03 pct in the titanium and to less than 0.5 pct in the osmium. The purity of the ruthenium is not known. The alloys were prepared by arc melting in a furnace of the type described by Schramm, Gordon, and Kaufmann.9 pecimens for X-ray diffraction were obtained by crushing the ingots and passing the resulting powders through a 200 mesh screen. Diffraction patterns were made with a powder

Jan 1, 1956

By G. M. Gordon, J. W. Spretnak, R. Speiser

AT present, considerable research is being directed toward the development of high-temperature, oxidation-resistant columbium alloys. Columbium. along with molybdenum and tungsten, exhibits good high-temperature strength. Unlike molybdenum and tungsten. however. columbium does not form a volatig oxide below 1375°c.l Although the outermost oxide formed on pure columbium, Cb2O3 is stable in air at elevated temperatures, it is not of a protective nature. It is porous and voluminous, and

Jan 1, 1959

Large equipment for quarrying and for the various stages of crushing and grinding are the trend for new and existing operations. Included are large size haulage units, fast drilling equipment, impact crushers and large mills capable of high tonnage rates for metallic and nonmetallic minerals. In grinding, large-size mills continue as the choice in industries where grinding constitutes a major portion of the processing. Typical is a 10 x 34 ft two-compartment mill in closed circuit with an 18-ft diam air separator for cement. Other cement mill sizes are in the order of 12 x 36 ft, 2500 hp; 10 x 37 ft ball and rod (wet), 1400 hp; 13 x 36 ft, 3000 hp; 13 x 40 ft (wet), 3000 hp. Several installations of combination ball and rod mills have been made, and one of the largest is 12 x 45 ft. In connection with the wet grinding of raw materials, the DSM 270-degree screen has been installed in several cement plants with the intention of producing a material finer than 50 mesh. In ore processing, large autogenous mills (121/2 x 20 ft) are being installed.

Jan 2, 1964

By G. H. Ashley

THE Pittsburgh coal bed stands today: as probably the largest contributor of wealth of any single mineral deposit in the world. If it is not, what other deposit is? To the present it has contributed more than 2,530,000,000 tons of high-grade coal from Pennsylvania alone, worth nearly $4,000,000,000. Since 1910 it has added more than $2,500,000,000 to the value of Pennsylvania's mineral output. There is estimated to be about three times as much coal still in this bed as has been mined. To realize the full value of this wonderful bed it must be remembered that the figures given are for one State only. To them should be added the figures for the same bed from West Virginia, Ohio and Maryland. Furthermore, as known by man, this great deposit is only a fraction of its original whole. Outliers in Somerset County, Pa., indicate that its original extent in Pennsylvania in an east and west direction was more than two times its present extent. Add to that the northward extension as indicated by outliers in northern Allegheny, Armstrong and Indiana counties,, and it seems safe to say that its original extent was not less than three times the area at present underlain by it. And as the subjacent beds of the Allegheny group are found still further eastward and northward, it is at least a possibility that it originally covered an area many times its present area.

Jan 10, 1926

By A. J. Brown

THE causes that have formed fissures in the earth's crust, and the agencies that have converted them into metallic beds, are amongst the most important and interesting subjects that can engage the attention of the mining engineer or the scientist. They lie at the very base of the whole system of vein geology, and until something like a correct theory can be arrived at with regard to them, the science as such is necessarily very incomplete. The data for such a theory, owing to a lack of careful and systematic observations in countries pre-eminently metalliferous, like Mexico and the States of Central and South America, are almost entirely wanting. Doubtless there has been abundant speculation on the subject, from the earliest times down to the present, in every country where mining has been one of the leading industries of the inhabitants. Perhaps the theory of Elie de Beaumont more nearly approaches a satisfactory explanation than that of any contemporary authority. The most recent investigations, both in Europe and on this continent, tend to produce the conviction that the phenomena of metallic fissure lodes are in some way connected with, and- dependent upon, plutonic agencies-not, however, as the direct product of volcanic activity, but rather as the result of chemical agencies called into play through its aid. Active volcanoes generally produce only the well-known types of volcanic rocks, though, perhaps, well-marked cases can be shown where these contain ores of copper, etc., evidently derived from the same deepseated source as their hypogene gangue. To prove that there is a connection between metallic lodes and plutonic rocks, it is not necessary that the ores should in all cases occupy fissures within the limits of masses of propylite, rhyolite, or other like rocks, or be

Jan 1, 1874

By A. J. Brown

The causes that have formed fissures in the earth's crust, and the agencies that have converted them into metallic beds, are amongst the most important and interesting subjects that can engage the attention of the mining engineer or the scientist. They lie at the very base of the whole system of vein geology, and until something like a correct theory can be arrived at with regard to them, the science as such is necessarily very incomplete. he data for such a theory, owing to a lack of careful and systematic observations in countries pre-eminently metalliferous, like Mexico and the States of Central and South America, are almost entirely wanting. Doubtless there has been abundant speculation on the subject, from the earliest times down to the present, in every country where mining has been one of the leading industries of the inhabitants. Perhaps the theory of Elie de Beaumont more nearly approaches a satisfactory explanation than that of any contemporary authority. The most recent investigations, both in Europe and on this continent, tend to produce the conviction that the phenomena of metallic fissure lodes are in some way connected with, and dependent upon, plutonic agencies— not, however, as the direct product of volcanic activity, but rather as the result of chemical agencies called into play through its aid. Active volcanoes generally produce only the well-known types of volcanic rocks, though, perhaps, well-marked cases can be shown where these contain ores of copper, etc., evidently derived from the same deepseated source as their hypogene gangue. To prove that there is a connection between metallic lodes and plutonic rocks, it is not necessary that the ores should in all cases occupy fissures within the limits of masses of propylite, rhyolite, or other like rocks, or be

By Wm. Reuben Webster

THE greatly enlarged demand for small sizes of seamless copper tube which has recently occurred, due particularly to the rapid growth of the electric household-refrigerator industry, has emphasized the superiority of phosphorized to tough pitch copper for the purpose of producing this commodity. In the manufacture of this material exceedingly heavy reductions by cold drawing are employed, customary practice involving as much as 90 per cent. reduction of cross-sectional area in four runs without intermediate annealing. Although this superiority has long been recognized by tube makers, no quantitative expression of it has heretofore been published. It is believed that the data herewith presented will serve this purpose. Recent investigators are not in agreement as to the relative mechanical properties of copper containing small amounts of oxygen as compared with copper containing sufficient oxygen to produce that condition known as tough pitch. Hanson, Marryat and Ford' found that "oxygen has a relatively small effect on the properties of copper." Johnson,2 on the contrary, states "it cannot be denied that it (tough pitch copper) is inferior, to deoxidized copper where severe mechanical manipulation is concerned." These authorities in the reports of their investigations, as might be expected from their conclusions, do not present data of a character requisite to a conclusive determination of the question.

Jan 1, 1927

Geologist or Mining Engineer who has had sufficient experience to make examination of a large area and who can report upon economic value of any minerals found. Work will extend over a period of 2 or more years. Location, India. R-1660. Assistant Superintendent of malleable and gray iron foundry, young man. Must have thorough molding experience, especially on squeezers, knowledge of mixture control and operation of air furnaces, cupolas, and annealing ovens college graduate preferred. R-1727. Engineer thoroughly familiar with distilling, evaporating and drying machinery. Capable of taking charge of entire evaporator department, including engineering and selling. New Jersey. R-155C. Experimental Draftsman familiar with small automatic mechanisms, principally those produced in large quantities by punch-press methods, such as adding machines or typewriters. New York City. R-1566. Patent Draftsman.-At least 2 years' experience on perspective rend-ering of small automatic machinery. New York City. R-1570. Designer.-Familiar with hydraulic work and capable of going ahead with detail and design work without supervision. Pennsylvania. R-1575. Superintendent or Foreman. Knowledge of ceramics, clay products, electric porcelain, tile, factory materials, etc. New York State. Good salary to right man. R-1578. Designer. Experienced in designing mining machinery, including electric hoists. Canada (Quebec). R-1589. Construction and Operating Superintendent. Executive and thor-oughly experienced in the zinc melting industry. Will have charge of construction of plant and its operation. Salary $6000 to start; increase to $8000 later. India. R-1593.

Jan 11, 1919

By Richard M. Foose

FIVE miles southwest of Mt. Holly Springs, Cumberland County, Pennsylvania, the Philadelphia Clay Co. has been mining and milling a white clay since 1896; for use in white cement, as a filler in rubber, pigment and paper, in the manufacture of insecticides, and for other minor purposes. Until late in 1942, when the mine was abandoned because of labor shortage, combined underground mining and surface stripping produced approximately 30,000 tons of clay a year, of which 10,000 tons were refined in the mill. GEOLOGY Lower Cambrian Antietam quartzite and the Montalto quartzite, stratigraphically older, trend N.55°E. and make a sharp 1600-ft. anticlinal ridge of the South Mountains. The Tomstown dolomite overlies the Antietam quartzite on the southeast flank of the anticline, which is displaced near its crest by a steeply dipping oblique fault. Erosion of the less resistant Tomstown formation has resulted in a narrow valley at an elevation of 700 ft. Directly on top of the Antietam quartzite and at the base of the Tomstown formation is a zone of sandy white clay, lenticular along the strike of the formations, ranging in thickness from 10 to 300 ft. within a mile. All of the formations dip steeply to the southeast, from 65° to vertical. The clay crops out at an elevation of about 1000 feet. ORIGIN AND CHARACTER The uppermost part of the Antietam formation is sericitic and schistose at many places, and at all these places weathering is in an advanced stage. The clay is the residual product of weathering of this sericitic quartzite or sandy schist. The crude clay has the physical aspect of a sandy kaolin, but there are large areas in the clay formation that are low in free silica, and commonly the 30 ft. adjacent to the Antietam quartzite is notably free of silica. The overlying Tomstown dolomite has been weathered almost completely to a mixed yellow and brown clay, which carries a zone of nodular and chunky limonite and manganese ore, 4 to 12 ft. thick, about l00 ft. from the contact with the white clay. In mining, this zone is an important "marker," indicating where the white clay may be expected in an advancing tunnel. The contact of the white clay formation with the yellow and brown clay of the Tomstown formation is relatively sharp, although the line of contact is irregular and therefore responsible for the lenticular character of the white clay formation. Following is an analysis of the refined clay containing less than one per cent of moisture when dried at 212°F.: Si02, 67.05 per cent; A1203, 22.27; Fe203, 0.40; CaO, 0.00; Ti02, 1.05; MgO, 0.52; Na20, 0.04; K20, 0.88; ignition loss, 7.65; total, 99.86.

Jan 1, 1944

By Ramkrishna Agarwal

The problem of the measurement of in situ stresses in rock masses has, in recent years, become one of the prime concerns of investigators and researchers in the field of rock mechanics. Numerous instruments have been developed for that purpose and various techniques have been used to determine the absolute values of these stresses at a point.l The "stress-relief" technique has gained the widest acceptance. In its usual application it relies on one of the two following principles: (1) Measurements of the changes in a "solid inclusion" in a borehole,2 or (2) Measurements of the diametral deformation of a borehole with a free boundary." The theoretical development, in the case of the latter, is based upon an evaluation of the deformation of a circular hole in an infinite plate under the action of a uniaxial stress field. Expressions for the deformations may be obtained by using either the plain strain or the generalized plane stress theoretical approach of the classical theory of Elasticity, which assumes that the material is linearly elastic, homogeneous and isotropic. The solution for the case of a biaxial stress field is obtained by the Principal of Superposition. The circular hole becomes elliptical after deformation takes place under the action of a uniaxial or biaxial stress field applied to the plate. In the practical application of the technique, the reverse procedure is applied. A borehole is drilled in the rock and a deformation-measuring

Jan 1, 1968

By Walter Miller

A surprising development during the year was the continued high demand for petroleum products and the high level of crude oil charges to the stills. Generally speaking, the petroleum industry during 1946 succeeded in producing a greater quantity of crude oil and petroleum products than in any of the war years, and considerably exceeded the production of any prewar year. Daily crude still charges averaged between 4,700,000 and 4,800,000 bbl per day for 1946 and about equaled the 1945 record, although most pessimistic 1945 guesses, predictions, or fears ranged, for 1946, from only 3,900,000 to 4,400,000 bbl per day. In spite of the high crude charge to the stills, total stock of crude oil was higher at the end of the year by some 7,000,000 to 8,000,000 bbl. A similar story holds regarding stocks of the principal refined products. Gasoline on hand at year's end was two to three million barrels lower, and was considered low for the expected demand during the coming high consuming season, while stocks of light and heavy fuel oils, although some higher than a year previous, hardly reached a comfortable level. The trend in gasoline of high octane number, which has resulted in a marked rise in. the antiknock quality by the end of 1945 (five or six numbers higher than during the war and one number higher than the prewar quality of civilian motor gasoline of 1941) was abruptly arrested by an acute shortage of metallic lead for manufacturing tetraethyl lead. Government action in the form of lead price control, rationing, and the setting of octane ceiling specifications to conform to the reduced ethyl lead compound available were enforced until abrogated at the end of the year. It will be interesting to see how rapidly the octane levels will resume the rising trend, as more metallic lead slowly becomes available for making greater quantities of ethyl lead compound. As octane quality rises over present levels the disadvantage of the refiner without catalytic cracking equipment will increase. Gasoline made by catalytic cracking, without addition of ethyl lead, approximates 77 octane by the official ASTM Motor Method test, compared with 66 for gasoline generally similar in volatility made by the older thermal cracking operation. Catalytic gasoline shows an even greater improvement in the Research octane number, the comparison being roughly 86 Research versus 71 Research octane for the thermal cracked product. This higher differential in Research octane is credited by many, although not universally so, as contributing to better road performance, and consequently resulting in a more desirable product marketwise. In some parts of the country a premium of roughly one fourth cent per gallon is now being paid for gasoline with higher Research octane made possible by including catalytic cracked product in the final blends. If such price differentials in favor of catalytic gaso-

Jan 1, 1947

By Walter Miller

A surprising development during the year was the continued high demand for petroleum products and the high level of crude oil charges to the stills. Generally speaking, the petroleum industry during 1946 succeeded in producing a greater quantity of crude oil and petroleum products than in any of the war years, and considerably exceeded the production of any prewar year. Daily crude still charges averaged between 4,700,000 and 4,800,000 bbl per day for 1946 and about equaled the 1945 record, although most pessimistic 1945 guesses, predictions, or fears ranged, for 1946, from only 3,900,000 to 4,400,000 bbl per day. In spite of the high crude charge to the stills, total stock of crude oil was higher at the end of the year by some 7,000,000 to 8,000,000 bbl. A similar story holds regarding stocks of the principal refined products. Gasoline on hand at year's end was two to three million barrels lower, and was considered low for the expected demand during the coming high consuming season, while stocks of light and heavy fuel oils, although some higher than a year previous, hardly reached a comfortable level. The trend in gasoline of high octane number, which has resulted in a marked rise in. the antiknock quality by the end of 1945 (five or six numbers higher than during the war and one number higher than the prewar quality of civilian motor gasoline of 1941) was abruptly arrested by an acute shortage of metallic lead for manufacturing tetraethyl lead. Government action in the form of lead price control, rationing, and the setting of octane ceiling specifications to conform to the reduced ethyl lead compound available were enforced until abrogated at the end of the year. It will be interesting to see how rapidly the octane levels will resume the rising trend, as more metallic lead slowly becomes available for making greater quantities of ethyl lead compound. As octane quality rises over present levels the disadvantage of the refiner without catalytic cracking equipment will increase. Gasoline made by catalytic cracking, without addition of ethyl lead, approximates 77 octane by the official ASTM Motor Method test, compared with 66 for gasoline generally similar in volatility made by the older thermal cracking operation. Catalytic gasoline shows an even greater improvement in the Research octane number, the comparison being roughly 86 Research versus 71 Research octane for the thermal cracked product. This higher differential in Research octane is credited by many, although not universally so, as contributing to better road performance, and consequently resulting in a more desirable product marketwise. In some parts of the country a premium of roughly one fourth cent per gallon is now being paid for gasoline with higher Research octane made possible by including catalytic cracked product in the final blends. If such price differentials in favor of catalytic gaso-

Jan 1, 1947

By Henry Howe

1. Introduction.-This paper is based in large part on the examination of two rings, shown in section in Fig. 4 to 15, cut from an eroded 14-in. (35.56-cm.) gun, liner, and containing, according to Booth, Garrett, & Blair: Carbon, 0.380 per cent.; manganese, 0.655 per cent.; nickel, 2.810 per cent.; vanadium, 0; chromium, a few hundredths of 1 per cent.; tungsten, 0; molybdenum, 0. These rings were received from Admiral Joseph Strauss, then Chief of Ordnance, U. S. Navy, through the kindness of Mr. Hudson Maxim, Chairman of the Committee on Ordnance and Explosives,, of the U. S. Naval Consulting Board.

Jan 2, 1918

Secondary blast holes are now being pierced in quartzite and sandstone quarries, using multiple hand-operated Jet-Piercing units supplied with oxygen, fuel and water from a compact mobile carrier. A unit of this type, operating in a Canadian quarry, enabled four Jet-Piercing blowpipes to pierce blast holes for two hours without shutdown. The piercing blowpipes used were developed by Linde Air Products Co., a division of Union Carbide and Carbon Corp. The mobile supply carrier was constructed by the quarry from specifications supplied by Linde and modified by the quarry operators for their particular use. Employment of the new self-contained unit, which allows up to four operators to pierce approximately 450 ft of blast hole without shutdown, accelerates rock removal operations. Normally, only two blowpipes are in operation at one time. Large boulders or ledges, which sometimes remain after primary blasting to hamper loading operations, can, in the case of certain hard rock, be prepared for reduction more rapidly with these new units than by any other means. A special feature of the new manual Jet-Piercing unit is the mobile gas and fluid supply carrier. It consists of a standard truck chassis fitted out with four banks of large standard-capacity oxygen cylinders, a steel-holding tank for fuel oil, and a gasoline-driven air compressor and tank for pressurizing the fuel oil tank. Cooling water for the blowpipes is supplied to the unit from a hose extension to the quarry supply line. Feeder lines from the oxygen cylinder manifolds and the oil and water tanks terminate in four sets of take-off stations on the control panel at the rear of the truck. As many as four hand Jet-Piercing blowpipes can be connected to the take-off panel by high-pressure rubber hoses. The hand Jet-Piercing blowpipe used with the mobile supply carrier is a highly portable device which can be manipulated comfortably by one operator. The blowpipe can pierce blast holes at rates up to 60 ft per hour, depending on the properties of the rock. Blast holes can be pierced at any angle from the vertical to the horizontal, making it necessary for the operator to drill from the top of the boulder. Hole diameter is held to approximately that which allows the use of a standard 11/8-in. diameter dynamite. The manual Jet-Piercing blowpipe has these important design features: a burner from which the combustion gases emerge at supersonic speeds (in excess of 6000 ft per sec); a hole-sizing shell which controls the minimum size of the hole and protects the copper burner; and a sliding shield which protects the operator against the steam and spallings ejected from the hole during the piercing. The Jet piercing process has been applied successfully in United States and Canadian quarries within the last several years as an advanced method of "drilling" blast holes.

Jan 1, 1952

This brief resume of the events transpiring in Mexico, culled from the daily New York newspapers since the last Bulletin went to press, does not show any degree of improvement in the situation. MEXICO SEEKS TO AVOID BLAME FOR BANDIT RAIDS All foreign passengers leaving Nogales for Mexico on the Southern Pacific or Mexico Railroad. whose business would take them through territory occupied by the Yaqui Indians or Mexican bandits were requested by Mexican Consul Emilio Tamez to sign a statement that they relieve the Mexican government of responsi-bility for anything which might happen to them while in that part of Mexico. The Mexican consul stated, says the N. Y. Tribune, that this was by order of Mexican Ambassador Ignacio Bon ill as, at Washington. When the State Department was advised of this activity Secretary Phillips, in a message to the consulate at Tampico, according to the N. Y. Tribune, asserted that "compliance with the waiver requirement will not interfere with the relation existing between the United States and its citizens and that Americans so complying will in no way lose the protection of this government."

Jan 11, 1919

COLLECTIVE bargaining, hereto-fore loudly proclaimed as one of the stout timbers of the Republic, has passed from the picture. The coup de gr[a]ce was struck by the President of the United States when he ignored his vested legal prerogative and seized the steel industry by the dubious authority of, his "inherent powers." Autocratic judgment by a single official replaced arbitration by the steel industry and labor union. This is the outcome of a battle which has been bitterly waged for months in the hazy atmosphere created by well oiled propaganda machines. Prior to government intervention, there was no clear picture of the issues at stake. All parties concerned marshalled their accountants to conjure up figures proving their respective contentions. The results were fed into public relations departments for embellishment and dissemination. Thus, the public was asked to believe on one hand, that the steel worker, who is second only to the coal miner in hourly wages, was entitled to an increase in pay and other benefits. Nothing was said about the effect-of such an increase on the national economy. Industry in turn pointed to declining profits after taxes, but failed to mention the more than a billion dollars spent on plant expansion, in addition to the payment of substantial dividends for 1951. With the intervention of the administration, the immediate issue became clear to freedom-loving Americans. Is the executive branch of the government above the law, or is it supposed to uphold and carry out the .laws of Congress? The present administration forgot that it is a servant of the public and has become despotic. The American people must obliterate this dangerous precedent which has been set by the administration or accept the. ominous consequences of submission. Fortunately, the strongest weapon of the citizen-the ballot -still remains. When democratic procedure is restored, stabilization of the economy will continue to challenge us. This is the main public stake in the steel controversy. Only a solution based on bed-rock democracy will work. If the emergency is real, and we must assume that it is, this is the time for sacrifice. Industry and labor must meet without rancor to resolve wage contracts through collective bargaining. The government role, under emergency conditions, must be to objectively maintain wage, and price ceilings in the interest of stabilization. Political expediency cannot be permitted to' influence these controls. Politics and not the public weal have been the guide lines for too long. We are at the cross roads. By all sober judgment, this is the time for Americans to take a militant interest in their government today. Tomorrow will be too late.

Jan 1, 1952

By Gilbert Soler

Producers of alloy steels recognize the importance of chemical composition in relation to the hot-working properties and the typical surface defects found in their product. Each analysis of steel has its own peculiar characteristics. Under conditions of standard mill practice each analysis is susceptible to certain types of defects. Mill practice must be varied to obtain the best combination of surface and internal quality in the product. Chemical composition influences the cast structure and crystallization characteristics of the ingot. It also determines the rate of heating and cooling, the plastic hot-working range, and the phase structure of the steel at various temperatures. as well as the tendency toward scale formation and decarburization. This paper endeavors to emphasize the manner in which chemical composition affects the various properties of steel, and to indicate the relative importance of these factors in relation to the hot-working properties and surface characteristics of killed steel. The influence of chemical composition may be outlined as follows: I. Effect on the cast structure of steel, including: A. State of deoxidation, and type of inclusions. B. Gas content of steel. C. Freezing point and melting point of steel. D. Crystallization characteristics and segregation. 11. Effect on the hot-working properties and surface characteristics of steel, including: A. Plastic hot-working range. B. Phase structures at hot-working temperatures. C. Rate of heating. D. Cooling characteristics. E. Scale formation. F. Surface decarburization. EFferect of Chemical Composition on Cast Structure of Steel State of Deoxidation and Type of Inclu-sions.—The state of deoxidation is limited by the final chemical analysis desired in the finished product, and is controlled primarily by carbon, manganese, silicon, and aluminum, and to a lesser degree by chromium, titanium, vanadium, or other deoxidizing elements. The degree of deoxidation affects the density of the cast structure and broadly classifies the steel as killed, semikilled, or rimming. This in turn manifests itself in surface characteristics. The manner and extent of deoxidation also controls the amount, type, and distribution of nonmetallic inclusions formed. The equilibrium of manganese, silicon and aluminum with the slags and pouring refractories with which the metal comes in contact is important, especially in regard to inclusions of fire-clay origin. Some surface Seams and hot-working difficulties can be traced to nonmetallic inclusions.

Jan 1, 1941

By Gilbert Soler

Producers of alloy steels recognize the importance of chemical composition in relation to the hot-working properties and the typical surface defects found in their product. Each analysis of steel has its own peculiar characteristics. Under conditions of standard mill practice each analysis is susceptible to certain types of defects. Mill practice must be varied to obtain the best combination of surface and internal quality in the product. Chemical composition influences the cast structure and crystallization characteristics of the ingot. It also determines the rate of heating and cooling, the plastic hot-working range, and the phase structure of the steel at various temperatures. as well as the tendency toward scale formation and decarburization. This paper endeavors to emphasize the manner in which chemical composition affects the various properties of steel, and to indicate the relative importance of these factors in relation to the hot-working properties and surface characteristics of killed steel. The influence of chemical composition may be outlined as follows: I. Effect on the cast structure of steel, including: A. State of deoxidation, and type of inclusions. B. Gas content of steel. C. Freezing point and melting point of steel. D. Crystallization characteristics and segregation. 11. Effect on the hot-working properties and surface characteristics of steel, including: A. Plastic hot-working range. B. Phase structures at hot-working temperatures. C. Rate of heating. D. Cooling characteristics. E. Scale formation. F. Surface decarburization. EFferect of Chemical Composition on Cast Structure of Steel State of Deoxidation and Type of Inclu-sions.—The state of deoxidation is limited by the final chemical analysis desired in the finished product, and is controlled primarily by carbon, manganese, silicon, and aluminum, and to a lesser degree by chromium, titanium, vanadium, or other deoxidizing elements. The degree of deoxidation affects the density of the cast structure and broadly classifies the steel as killed, semikilled, or rimming. This in turn manifests itself in surface characteristics. The manner and extent of deoxidation also controls the amount, type, and distribution of nonmetallic inclusions formed. The equilibrium of manganese, silicon and aluminum with the slags and pouring refractories with which the metal comes in contact is important, especially in regard to inclusions of fire-clay origin. Some surface Seams and hot-working difficulties can be traced to nonmetallic inclusions.

Jan 1, 1941

By H. M. Hobart

This paper deals principally with investigations undertaken by the Welding Research Sub-committee of the Welding Committee of the Emergency Fleet Corporation. The general object of the investigations has been to extend the use of welding in the construction of merchant ships and, specifically, to provide a definite basis for obtaining the greatest economy and efficiency in employing welding in place of riveting in the construction of the hulls of such ships. Composition of_ Ship-plate Steel The chemical composition of the steel employed in such hull construction varies with the thickness of the plates. Through the courtesy of Mr. H. Jasper Cox, of Lloyd's Register of Shipping, the following information may be given concerning the kind of steel plate employed in American shipyards in 1918 for the hull construction of merchant ships. Lloyd's requirements do not relate to the chemical composition. They require a tensile strength of 58,000 lb. per sq. in. (40.75 kg. per sq. mm.) for their lower limit and 72,000 lb. per sq. in. (50.59 kg. per sq. mm.) for their upper limit. For the information of the Committee, Lloyd's obtained from their surveyors at various works data of the carbon content, which is as follows: Works Carbon Content for Plates 1/4 In. Thick 1 In. Thick A..................... 0.14 0.23 B..................... 0.14 0.25 C2.................. 0.19 0.25 D................. 0.20 0.30 E Upper limit..... 0.35 Lower limit..... 0 24 0.29 Upper limit,.... 0.25 0.30 Lower limit..... 0.21 0.27 Upper limit..... 0.25 0.35 Lower limit..... 0.22 0.28

Jan 1, 1920

By W. J. Babyak, F. N. Rhines

It has long been supposed that, regardless of the mechanism by which grain boundaries increase the hardness of a ductile metal, the effect should be linearly proportional to the grain boundary area. At the present time two methods for determining grain boundary area in an isotropic aggregate are available. The first, derived by Angus and Summers,' presumes that the grain boundary area is equal to 3vn, where n is the number of grains per sq mm in a random section through the metal. This estimate is based upon the assumption that the grains are equivalent to cubes whose faces correspond with the grains as observed in the micro-section. Measurements on copper, bronze, and a brass showed that a nearly linear relation exists between 3vn and hardness. This is illustrated, for the case of brass, in Fig. 1. The second method, developed independently by Smith and Guttman2 and by Duff in, Meussner, and Rhines,3 is absolute and employs a simple linear intercept count for measuring grain boundary area. It involves no assumptions with respect to the shape and distribution of the grain boundaries. The total surface in unit volume is 2 NL , where NL is the number of intercepts between grain boundary and unit length of a test line passed randomly through the sample. In practice, NL,, the average number of grain boundaries intercepted by unit length of traverse across a prepared microsection, is ob-

Jan 1, 1961