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By M. B. Willey

The Louisiana Continental Shelf is a submarine area extending offshore as much as one hundred miles. The Gulf bottom in this region varies considerably in extent, profile and composition and consists largely of sedimentary deposits, predominantly those of the Mississippi River. It is very young in a geological sense. Up to the present time few major structures have been erected offshore in the Gulf and no comprehensive preliminary tests have been carried out. Results of pile driving tests are of little value as actual bearing capacities far exceed the dynamic resistance to driving as measured by conventional formulas. Soils encountered are, with few exceptions, cohesive and piling consequently develop their supporting power through surface friction. Because of the time required and relatively high costs, no complete load tests have been made. The results of those tests which have been made, and information obtained from pulling piling in one structure, indicate that design loadings could be considerably increased, and it is contended that comprehensive preliminary investigations including an actual load test, combined with borings and examination of materials encountered by competent soil experts, would effect economies in design far in excess of their cost. The Louisiana Continental Shelf—General The Louisiana . . . continental shelf is a submarine area which extends seaward for as great a distance as one hundred miles off the present shoreline. The Gulf bottom in this region is characterized by low slopes and its outer margin is outlined by the fifty fathom (300 ft.) contour. South of the margin of the shelf the slopes steepen abruptly in the continental slope zone and plunge into the deeps of the Gulf of Mexico.l The engineer who is called upon to design a structure on this shelf is concerned only with the uppermost portion to a depth generally not to exceed Ioo to 150 ft. This layer is very young in a geological sense, and it has the characteristics usually associated with infancy. A few of these are lack of strength, lack of uniformity, and high water content. It consists of the sedimentary deposits of the various rivers and streams entering the Gulf. These streams are all heavily burdened in quantities sufficient to fill the areas at their mouths, were it not for the fact that continual subsidence, equal or greater in amount and acting directly opposite, prevail over the sedimentary workings of the streams. This subsidence has been estimated by geologists to be at the rate of at least one foot per century. Influence of Mississippi River The Mississippi River, which has been the predominant factor in the formation of practically all the Louisiana continental shelf, is one of two rivers flowing into the Gulf that have been able to build protruding deltas. The Mississippi has done so because of its enormous size and load. It deposits sediments in amounts sufficient to replace and actually gain on the amount of subsidence.

Jan 1, 1949

Dr. Rausch, from your vantage point as educator, engineer, and corporate executive, what would you say is the most fundamental need that must be satisfied for the continuing welfare of our society, our industry and our profession?

Jan 3, 1977

By Nicholas J. Grant, H. C. Chang

EMPHASIS on the importance of grain boundary sliding as a mode of deformation at elevated temperatures has been presented elsewhere.' The extent to which boundary sliding occurs under certain creep conditions has been determined for high purity aluminum2,3 and aluminum alloys.' In general, boundary deformation extends quite far into the adjoining grains, resulting in a rather wide band of deformation along the grain boundaries. This has led some investigators to doubt that grain boundary sliding consists of shearing along the boundary surface; it has been contended instead that boundary sliding is a result of concentrated slip in the neighborhood of the deformed grain boundaries."' The purpose of this note is to present evidence that grain boundary sliding takes place by a bulk shear process. gh purity polycrystalline aluminum, wherever and whenever there is grain boundary sliding, boundary migration and concentrated deformation along both sides of the deformed boundary are associated with it. Therefore, it has been rather difficult to obtain unambiguous evidence of boundary sliding. On the other hand, it would be expected in certain alloys of aluminum, when tested under particular conditions. that the severity of the interfering effects of boundary migration and concentrated deformation along the deformed boundary might be reduced. Current research in this laboratory' shows that a 20 pct Zn-A1 solid solution alloy fractures in an intercrystalline manner during creep at 500°F with a small total elongation of not more than about 14 pct, and that it does so with extremely limited grain boundary migration. Accordingly, this alloy was chosen for the present study. The experimental procedure was similar to that used in previous work and has been presented elsewhere.' Two parallel flat surfaces were milled from a round specimen. The gage portion of the specimen was 1 in. x .09 in. x .17 in. The specimens, which were annealed at 1030°F for 24 hr, showed two to four grains across the width of the test bar. The specimens were subjected to creep at 500°F at stresses of 2000 to 5000 psi. The rupture times were from 10 sec to 3 hr. Appreciable boundary sliding occurred in all the tests. A typical example of boundary sliding is shown in Fig. 1. (The tension axis is vertical in the micrographs.) Sliding has taken place along the boundary between grains A and B unaccompanied by important boundary migration. The sharpness of the offset at the triple point can be clearly seen in grain C. As a result of sliding along the boundary between grains A and B, a new boundary surface between grains A and C was created. The offset at the triple point is about 0.07 mm. This boundary sliding is accompanied by the formation of rather sharp kinking bands and, of course, slip on several slip systems in grain C. This type of deformation has been referred to as fold formation' in previous work with high purity aluminum.

Jan 1, 1957

By Herbert Clark Hoover, Lou Henry Hoover

SINCE I have written of the varied work of pre- paring the ores, I will now write of the various methods of smelting them. Although those who bum, roast and calcinea the ore, take from it something which is mixed or combined with the metals ; and those who crush it with stamps take away much ; and those who wash, screen and sort it, take away still more; yet they cannot remove all which conceals the metal from the eye and renders it crude and unformed. Wherefore smelting is necessary, for by this means earths, solidified juices, and stones are separated from the metals so that they obtain their proper colour and become pure, and may be of great use to mankind in many ways. When the ore is smelted, those things which were mixed with the metal before it was melted are driven forth, because the metal is perfected by fire in this manner. Since metalliferous ores differ greatly amongst themselves, first as to the metals which they contain, then as to the quantity of the metal which is in them, and then by the fact that some are rapidly melted by fire and others slowly, there are, therefore, many methods of smelting. Constant practice has taught the

Jan 1, 1950

By Robert Henderson

Several very interesting articles have been written on the caving system of mining, but most of these papers have dealt separately with the slusher system or the chute and grizzly system. In this paper, a comparison will be made of the two methods, both of which are being used at the Climax mine. The mine is on the Continental Divide, in central Colorado, at an altitude of approximately 11,500 ft. above sea level. The long, cold winters, characteristic of the high Rockies, create a number of operating problems not usually found in other mining areas. The Ore Body The Climax ore body is just east of the Mosquito fault. This structural deformation has brought the granite on the east against the sedimentary rocks on the west. The ore occurs in an intensely altered granite and schist around a silicified granite core. The ore is in a highly fractured zone of moderate silicification. The principal mineral, molybdenite, is found in these fractures. Barren dikes of granite porphyry cut through the ore body and core with no apparent regularity. The grade of the ore is fairly uniform and gradually decreases toward the footwall core and also into the hanging-wall granite. The footwall and hanging wall are determined entirely by assays. The ore body is roughly dome-shaped, with the apex truncated at the surface. It is covered to varying depths with talus. A horizontal section of the ore body on the Phillipson level appears as an annular ellipse surrounding the footwall core. The ring of ore varies in width from 300 ft. to as much as 800 ft. The north-south axis of the core is about 1200 ft. and the east-west axis is about 1800 ft. In the ore zone, the rock is sufficiently strong to maintain reasonably large openings, and openings larger than haulage drifts usually have to be supported. The ore is cut by a great many fractures and shears and breaks into rather large blocks when caved, necessitating considerable secondary blasting. The waste that overlies the ore body breaks relatively fine in comparison with the size of the blocks of the caved ore and tends to run through the broken ore in the cave, causing dilution unless the draw is carefully controlled. Mining Systems For several years the ore was mined by the chute and grizzly system, a system that differs from that used in other caving mines only in the size of openings and equipment. In the chute and grizzly system, main haulage laterals were driven along the footwall core and also along the hanging wall. Between these laterals, at

Jan 1, 1946

By A. J. Lena, M. F. Hawkes

Changes in hardness, tensile properties, microstructure, electrical resistance, and X-ray diffraction effects indicate that lattice strains are necessary for the embrittlement of ferritic stainless steels when heated for relatively short times at 475°C (885°F). It is suggested that 475°C (885°F) embrittlement is due to the accelerated formation of an intermediate stage in the formation of s under the influence of these strains. FERRITIC stainless steels (low carbon alloys of iron with more than 15 pct Cr) are subject to two forms of embrittlement when heated in the temperature range of 375° to 750°C. The embrittlement which occurs after long time heating between 565" and 750°C is well understood; it is caused by the precipitation of the hard, brittle s phase. Sigma is an intermetallic compound of approximate equi-atomic composition with an extended range of formation in Fe-Cr alloys. The maximum temperature at which this form of embrittlement can occur is dependent upon chromium content; and is approximately 620°C for a 17 pct Cr steel and 730°C for a 27 pct Cr steel. The other form of embrittlement occurs after relatively short heating periods in the range of 375" to 565°C; in the higher chromium steels, hours may be sufficient as compared to months for s embrittlement. This phenomenon is not at all well understood and several controversial theories have been proposed. The rate and intensity of embrittlement increase with increasing chromium content but the maximum rate occurs at 475°C re-gardless of chromium content. As a result of this, the phenomenon has been termed 475°C (885°F) embrittlement. The effect of 475°C embrittlement on the properties of ferritic stainless steels has been thoroughly reviewed by Heger.1 The embrittlement causes a pronounced decrease in room temperature impact strength and ductility, a large increase in hardness and tensile strength, and a decrease in electrical resistivity and corrosion resistance. Microstructural changes accompanying embrittlement are minor and difficult to interpret with a general grain darkening, appearance of a lamellar precipitate, grain boundary widening, and precipitation along ferrite veins having been reported at various times. With the exception of reported line broadening, X-ray diffraction studies by conventional Debye analysis of solid samples have been of little value. BY making use of electron diffraction methods, Fisher, Dulis, and Car-roll' have recently shown the existence of a chromi-um-rich, body-centered cubic phase in 27 pct Cr steels which had been aged at 482°C (900°F) for as long as four years. Two types of theories have been advanced to account for the embrittlement. The first of these requires the precipitation of a phase not inherent in the Fe-Cr system with various investigators suggesting a carbide,3 nitride,3 phosphide,4 or oxide." Theories of this type have difficulty accounting for the influence of alloying elements on the embrittlement and for the facts that a minimum chromium content is necessary for embrittlement and the intensity of embrittlement increases with increasing chromium content. The second type of theory that has been proposed relates 475°C embrittlement to s phase formation which is inherent in the Fe-Cr system. An assumption of this kind can adequately explain the influence of alloying elements, for they exert an effect on 475°C embrittlement similar to that on s phase for-mation as can be seen in Table I. The minimum chromium content is essentially the same for both phenomena and it has been shown12,13 that s is a stable phase in the embrittling temperature range. In addition, it has been reported14,15 that pure alloys embrittle to the same extent as commercial type alloys. There are, however, several factors which have prevented complete acceptance of a s phase theory. Foremost of these is that the embrittlement can be removed by reheating for short time periods above 600°C, which in the higher chromium steels is within the stable s region. No s has ever been observed after one of these curing treatments, nor has any s been found as a result of embrittlement at 475°C. In addition, the simple precipitation of s cannot explain the time-temperature relationships for reactions between 350°and 750°C. This behavior is shown schematically in Fig. 1. Newell 16 and Ried-rich and Loib4 have shown that 475°C embrittlement follows a C-type curve as illustrated, while Short-

Jan 1, 1955

By G. P. Hulst

THE Parkes process lead refinery of the International Lead Refining Co., at East Chicago, was built by the International Smelting & Refining Co. to treat the lead bullion produced by its Tooele plant, at Tooele, Utah. The plant was designed and constructed under the direction of the writer. Ground was broken Apr. 16, 1912, and exactly six months later the plant was in operation and lead was being cast. The capacity of the plant, running 25 days per month, is 5,000 tons. The four products of the plant are common lead, corroding lead, antimonial lead, and Doré bullion. The site is an area, 64 acres in extent, lying north of 151st Street, between McCook Avenue and the Canal. The Indiana Harbor Belt Railroad, Baltimore & Ohio Chicago Terminal, and Pennsylvania Railroad enter, the yard at the plant. There are five, storage tracks and space for storing 100 cars in the yard. The main lead to the storage tracks passes over a 100-ton track scale on entering the yard...

Jan 8, 1914

By D. J. McAdam

IN a recent survey of the literature, the author has found evidence incompatible with prevalent views regarding the technical cohesive strength and yield strength of metals. Some of the evidence regarding the technical cohesive strength was presented in a previous paper,21 and views were presented that are believed to be in better accord with the evidence. In that paper, it was shown that the technical cohesion limit (contrary to prevalent views) varies with the combination of principal stresses,† and that the influence of plastic deformation on the technical cohesive strength is not in accordance with prevalent views. In this paper, consideration will be given to both the technical cohesion limit and the yield stress as affected by the combination of principal stresses. Evidence will be presented that the variations of the yield stress and the technical cohesion limit with the combination of principal stresses are not in accordance with prevalent views. Consideration will also be given to ductility and work-hardening capacity, which depend on the initial difference between the technical cohesion limit and the yield stress. By the "technical cohesion limit" is meant the mean stress at actual or potential* fracture. An example of a technical cohesion limit is the "true" breaking stress of a tension-test specimen, the breaking load divided by the sectional area at fracture. The cohesion limit thus obtained for a ductile metal, however, has been greatly altered by the plastic deformation. It is important to consider the cohesion limit of the metal prior to this deformation, and the variation of the cohesive strength with plastic deformation. The relation between the cohesion limit and the corresponding flow stress† determines the ductility of a metal and the energy that it will absorb before fracture. In this paper, as in the previous paper,21 tensile stresses will be viewed as positive and compressive stresses as negative. The algebraically greatest principal stress will be designated S1, the least principal stress will be designated S3, and the intermediate principal stress will be designated S2. In the previous paper, attention was confined to stress combinations with two of the principal stresses equal (with the intermediate principal stress S2 equal either to S3 or S1). In this paper, consideration will also be given to the effect of stress combinations with all three principal stresses unequal. In the earlier sections of the paper (pp. 1 to 14), attention will be confined to stress combinations with

Jan 1, 1942

By Ian MacGregor

INTRODUCTION I retired in 1977 and have been enjoying myself ever since doing odd jobs for various people - on occasions, politicians. I commend it to you as post retirement - get involved in situations that nobody else will take on. It produces all sorts of excitement, it is a lot of fun and, courtesy of the media, you provide great raw material for their current Punch and Judy shows. The example of the adventures in the Escondida financing made me think about the history of the minerals industry in the United States. In order to see more clearly what is going to happen in the future, we have to look at the past and what we have learned, and try to extrapolate from that a scenario for the future. This paper is about global material cycles and the financial needs of the extractive industries. Since about 2,000 years B.C. we have been living in the Iron Age. Since about 4,000 B.C. we have been living in the Copper Age. These have been the two foundations of modern industrial society. Understanding the use of metals and materials helps us understand the civilization in which we live today. Let me focus more closely on the United States, particularly in this century. In the first two-thirds of this century the United States was growing and expanding and developing. It was providing for its inhabitants a society which was enjoying the benefits of a rising standard of living, improved opportunities and the ability to support a population growing at quite a dramatic rate. It is still growing. In the Department of Commerce, there is a clock that shows how many people there are in the United States. It turns all the time; the numbers are going up. On January 21,1980, when Ronald Reagan was sworn in as President, the number on that clock was a little over 220 million, and in the last week before he left, it was travelling towards 245 million. During his period in Washington, we have added , the equivalent of one total state such as California. That gives the dimensions of the U.S. appetite for raw material inputs. The inputs are of critical importance. COMPARATIVE ADVANTAGE During the first two-thirds of this century, the minerals sector enjoyed comparative advantages. There was a clear understanding of the importance of minerals enshrined in the tax legislation of the country from the early decades of this century - the depletion allowance. No other country identified as clearly that the supplies of minerals were finite. As they are used up, just as with a wearing-out machine, one must get capital back to replace the resource when the time comes. Within the last decade, that idea has been questioned and criticised. It is now seen as giving money away to a preferred part of the economy, instead of recognizing what depletion is all about. In previous times it insured that the U.S. always was able to regenerate the capital in its minerals industry, so that it could remain competitive. The U.S. had plenty of everything, including energy. We had a growing population. Equally important, we had an agriculture that led the world in productivity, even as far back as the turn of the century. It continues to do so. We still retain that comparative advantage, an ability to produce our foodstuffs in quantity and quality at excellent cost. Look at another ingredient of our comparative advantage, the energy position. We ran through the first two-thirds of the century with ever- decreasing energy costs. In the 1940s and 1950s the coal industry went into a decline. Why? Because the $3.00 - $5.00 a ton cost of mining coal in the U.S. represented relatively expensive energy. A ton of good grade bituminous coal contains 25 million BTU's. $0.20 a million BTU's represents $5.00 a ton at the pithead. That price was undermined by the increasing ability to find petroleum at even lower costs. At the apex of the growth of development of the American dominated

Jan 1, 1990

By T. L. Joseph

It is a distinct privilege to participate in this meeting convened to honor the memory of Henry Marion Howe, a distinguished scientist and metallurgist. Many have added to our rapidly growing fund of metallurgical knowledge but few have made the unique contribution of formulating basic concepts essential to an over-all comprehensive view of the subject of metallography. Of those previously selected to deliver this lecture, several have added a personal touch to their discourse because they were able to refer to their associations with Dr. Howe. It was not my good fortune to know him or to enjoy his inspiring influence. Like most of you, my contact has been with his published works, which are outstanding in that they provide lucid, detailed expositions of the nature and behavior of metals and alloys. His deep understanding and clarity of expression have greatly accelerated our progress in metallography and in the use of metals. The degree to which a man's thinking, experimentation and writing contribute toward an understanding of basic laws and phenomena determines whether his life's work is of transitory or permanent value. This occasion appropriately recognizes the fundamental importance of Dr. Howe's pioneer work in the field of metallurgy.. On two former occasions, gray iron was selected as a subject for discussion. The fact that the production of pig iron has not been discussed before does not reflect any lack of interest on the part of Dr. Howe or former lecturers in the process that underlies the production of steel. Although Dr. Howe's work in his later years centered around metallography, his earlier publications show a considerable interest in the production of iron and steel. He recognized that in the ascending spiral of metallurgical advancement we are not winding a single thread but are weaving a complex fabric. Specific evidence of his interest in the production of pig iron may be found in his book' on The Metallography of Cast Iron and Steel. In explaining why blast furnaces have been in constant use for about 600 years, he says: "The process is economical because it utilizes with extraordinary completeness the calorific power of the coke due to the thorough transfer of heat from the gaseous products of combustion to the charge." This emphasis on heat transfer, overlooked in many more extended and more recent discussions of the blast-furnace process, illustrates Professor Howe's ability to see the essentials. Other distinct advantages of the blast furnace, such as the removal of- much of the sulphur and practically all of the oxygen, were mentioned. It was also stated that although the blastfurnace process is complex in nature, its outward form is comparatively simple, thus permitting large-scale production at small labor costs. All who contemplate the production of metallic iron from its ores by any other process might well consider the

Jan 1, 1947

By T. L. Joseph

It is a distinct privilege to participate in this meeting convened to honor the memory of Henry Marion Howe, a distinguished scientist and metallurgist. Many have added to our rapidly growing fund of metallurgical knowledge but few have made the unique contribution of formulating basic concepts essential to an over-all comprehensive view of the subject of metallography. Of those previously selected to deliver this lecture, several have added a personal touch to their discourse because they were able to refer to their associations with Dr. Howe. It was not my good fortune to know him or to enjoy his inspiring influence. Like most of you, my contact has been with his published works, which are outstanding in that they provide lucid, detailed expositions of the nature and behavior of metals and alloys. His deep understanding and clarity of expression have greatly accelerated our progress in metallography and in the use of metals. The degree to which a man's thinking, experimentation and writing contribute toward an understanding of basic laws and phenomena determines whether his life's work is of transitory or permanent value. This occasion appropriately recognizes the fundamental importance of Dr. Howe's pioneer work in the field of metallurgy.. On two former occasions, gray iron was selected as a subject for discussion. The fact that the production of pig iron has not been discussed before does not reflect any lack of interest on the part of Dr. Howe or former lecturers in the process that underlies the production of steel. Although Dr. Howe's work in his later years centered around metallography, his earlier publications show a considerable interest in the production of iron and steel. He recognized that in the ascending spiral of metallurgical advancement we are not winding a single thread but are weaving a complex fabric. Specific evidence of his interest in the production of pig iron may be found in his book' on The Metallography of Cast Iron and Steel. In explaining why blast furnaces have been in constant use for about 600 years, he says: "The process is economical because it utilizes with extraordinary completeness the calorific power of the coke due to the thorough transfer of heat from the gaseous products of combustion to the charge." This emphasis on heat transfer, overlooked in many more extended and more recent discussions of the blast-furnace process, illustrates Professor Howe's ability to see the essentials. Other distinct advantages of the blast furnace, such as the removal of- much of the sulphur and practically all of the oxygen, were mentioned. It was also stated that although the blastfurnace process is complex in nature, its outward form is comparatively simple, thus permitting large-scale production at small labor costs. All who contemplate the production of metallic iron from its ores by any other process might well consider the

Jan 1, 1947

By R. S. French

THE purpose of this paper is to present data that have been obtained during the past two years concerning the effects of prior cold-work and temperature and time of anneal upon the recrystallization and grain growth of 70-30 cartridge brass. It was desirable to study certain of these phases so that an accurate picture of the principles of the subject could be shown. The work is not intended to provide explicit annealing data, but to provide material examples that may help to clarify analogous problems concerning this alloy. Specifications often set limitations upon the grain size of annealed materials because of the importance of grain size upon subsequent manufacturing operations. It was, therefore, worth while to study the variables that affect the recrystallized grain size of this material. C. H. Mathewson and A. Phillips,1 W. R. Webster,2 and others have presented annealing characteristic curves of this alloy. A recent typical curve presented by R. S. Pratt3 is shown in Fig. I. The tensile properties and grain sizes are shown as functions of the annealing temperature. Such curves serve as a useful guide in determining the physical properties of annealed material, but as they are made generally under carefully controlled laboratory conditions they do not indicate the performance of metal annealed in a mill muffle, where conditions are different and the amounts of metal require necessarily longer heating times and temperatures. Study of the effect of time and temperature upon grain growth and subsequent recrystallization was made with a coil of metal having the following analysis: 70.04 per cent copper; 0.007 lead; 0.007 iron; 0.00 tin; 0.00 silicon; 0.001 nickel; 0.000 phosphorus; balance zinc. The sample coil was obtained from metal that had been rerolled from hot-rolled mill stock, and was received at 0.228-in. gauge, soft, with a grain size of 0.125 mm. This material was then rolled 43.5 per cent to 0.125-in. gauge and annealed to a 0.053-mm. grain size. In this condition, samples were cut and used in all of the experimental work reported in this paper. TIME The first study was of crystal growth at a constant temperature over a moderate length of time. Material was cut from the stock coil at 0.129-in. size and rolled 75 per cent hard to 0.032-in. gauge. From this piece small samples were cut ½ by 2 in., suitable for grain-size determinations. Twelve samples were placed in an electric furnace uniformly across the width, approximately an inch from the floor, A thermocouple was wired to the center sample, so that the approximate metal temperature could be followed. At various

Jan 1, 1944

By N. B. Pilling, R. E. Bedworth

The corrosion of metals is one problem on which time and thought have been expended for many years. In the effort to avert the destructive action of a hostile environment, attention has been directed almost entirely to the conditions under which most metallic structures are called upon to perform, and the extensive and complicated phenomena attending the corrosive action of atmospheric agencies, acting at the ordinary atmospheric temperatures, have been studied, but there is unanimity of opinion regarding many fundamental facts. One neglected phase is the corrosive action of various gases upon metals exposed to temperatures considerably higher than the atmospheric range, and more especially the attack of atmospheric oxygen upon exposed metallic surfaces. That the problem is difficult is connoted by the practical dominance of industrial electric heating by alloys of one type (nickel-chromium). Proprietary interest may account, in part, for the paucity of information available upon even the most general factors determining the behavior of metals and alloys when exposed to such exacting conditions. The present paper gives some conclusions reached as the result of experimental work, extending over several years, on the mechanism and contributory factors of the high-temperature oxidation of a number of simple unalloyed metals; it is free from experimental detail and proof. High-temperature metallic oxidation may be considered as a phase of metallic corrosion. The scheme outlined below, in which corrosive agent and environment are the principal criteria, is one way of analyzing the several groups of corrosion phenomena. Erosion.—Disintegrating or destructive action by physical causes. Corrosion.—Disintegrating or destructive action by chemical causes. Low-temperature Corrosion.—Solid participating phases essentially immobile: (a) Gaseous agent; (b) liquid agent: action electrolytic and action non-electrolytic. High-temperature Corrosion.—Solid participating phases possess diffusive mobility: (a) Liquid agent; (b) gaseous agent: reducing gases, oxidizing gases. (1) Water; (2) miscellaneous elemental and combined oxygen.

Jan 1, 1923

By R. E. Bedworth, N. B. Pilling

The corrosion of metals is one problem on which time and thought have been expended for many years. In the effort to avert the destructive action of a hostile environment, attention has been directed almost entirely to the conditions under which most metallic structures are called upon to perform, and the extensive and complicated phenomena attending the corrosive action of atmospheric agencies, acting at the ordinary atmospheric temperatures, have been studied, but there is unanimity of opinion regarding many fundamental facts. One neglected phase is the corrosive action of various gases upon metals exposed to temperatures considerably higher than the atmospheric range, and more especially the attack of atmospheric oxygen upon exposed metallic surfaces. That the problem is difficult is connoted by the practical dominance of industrial electric heating by alloys of one type (nickel-chromium). Proprietary interest may account, in part, for the paucity of information available upon even the most general factors determining the behavior of metals and alloys when exposed to such exacting conditions. The present paper gives some conclusions reached as the result of experimental work, extending over several years, on the mechanism and contributory factors of the high-temperature oxidation of a number of simple unalloyed metals; it is free from experimental detail and proof. High-temperature metallic oxidation may be considered as a phase of metallic corrosion. The scheme outlined below, in which corrosive agent and environment are the principal criteria, is one way of analyzing the several groups of corrosion phenomena. Erosion.—Disintegrating or destructive action by physical causes. Corrosion.—Disintegrating or destructive action by chemical causes. Low-temperature Corrosion.—Solid participating phases essentially immobile: (a) Gaseous agent; (b) liquid agent: action electrolytic and action non-electrolytic. High-temperature Corrosion.—Solid participating phases possess diffusive mobility: (a) Liquid agent; (b) gaseous agent: reducing gases, oxidizing gases. (1) Water; (2) miscellaneous elemental and combined oxygen.

Jan 1, 1923

By D. D. Dunlop, J. R. Welker

The growing interest in the use of CO, in crude oil recovery increases the need for data on the effect of CO, on hydrocarbon physical properties. Data are presented on the solubility of CO, in various dead oils, the swelling changes in CO2-oil solutions and the effect of CO, on dead oil viscosity. This latter property shows the most pronounced effect, with viscosity reductions up to 98 per cent of the uncarbonated viscosities. An empirical method of estimating the viscosity of carbonated oils is presented. The apparatus and procedures used are described in sufficient detail to allow others to make similar studies. INTRODUCTION The effect of dissolved carbon dioxide on the swelling and viscosity reduction of specific hydrocarbon oils has been observed and recorded by a number of investigators.'- me object of this paper is to offer a means of predicting these effects for crude oils free from natural gas, using the dead state viscosity and gravity of the crude oils. The CO, solubility and swelling of numerous crude oils were determined in a visual cell at various pressure levels. The viscosity of the oils carbonated to various pressure levels was then determined by measuring the pressure drop across a capillary tube. From these data, the physical properties were correlated empirically. The resulting correlations allow the prediction of CO, solubility, swelling and viscosity reduction if the dead state gravity and viscosity of the oils are known. SOLUBILITY AND SWELLING MEASUREMENT EQUIPMENT AND PROCEDURE A high pressure visual cell was installed in a constant temperature cabinet. A test gauge was attached at the top of the cell for pressure measurement, and a line was run through the cabinet wall to a wet test meter which was used for volumetric measurement of the gas. The first step in making a test run was to put the oil in the cell up to a level about half to two-thirds of the total volume. This required about 50 to 65 ml of oil. carbon dioxide was then bubbled up through the oil for a time during which the pressure of CO2 in the cell was kept above 800 psia. Saturation of the oil with CO2 at this pressure and ambient temperature was confirmed by slowly bleeding CO2 through a valve to the atmosphere. If the oil was completely saturated with CO2, bubbles of gas would form in the oil at the first small decrease in pressure. If the oil was under-saturated, no bubbles formed until the pressure was decreased to the saturation pressure existing in the oil. If this saturation pressure was lower than that desired, more CO2 was bubbled through the oil until the desired level was reached. After saturation at ambient temperature was completed, the cabinet temperature was adjusted to the desired level and the cell was allowed to reach temperature equilibrium. After temperature equilibrium was reached, the pressure was again decreased slightly, and the oil again checked for full CO2 saturation at the cell pressure. The pressure now had changed because of the difference in solubility of the CO, in the oil at higher temperatures and the expansion of CO2 as the temperature increased. The outlet tube from the cell was then connected to the wet test meter and the CO2 was allowed to flow slowly out of the cell and through the wet test meter at ambient temperature and pressure. The water in the wet test meter had previously been saturated with CO2 at ambient temperature and pressure by allowing CO2 to flow continuously through it lor a period of several hours. The gas flow was stopped at several pressures during the run and the cell was allowed to come to equilibrium; this made possible the measurement of solubility and swelling data at the intermediate pressures. The volume of the oil in the cell was recorded at each of the equilibrium pressures in order to obtain swelling data. DATA AND RESULTS The solubility of CO2 in the oil was calculated by the relationship V — V, where R. = solubility of CO, in crude oil, cubic feet of CO, measured at 60F and 1.0 atm/ bbl of dead state oil at the temperature under which solubility was measured, V, = volume of gas released from the cell between the saturation pressure and zero pressure, corrected to 60F and 1.0 atm, cu ft, V, = volume of CO: contained in the gas space above the oil, corrected to 60F and 1.0 atm, cu ft, and V, = volume of the dead oil in the cell in bbl at the temperature of the run. The volumetric data of Sage and Lacey' were used to calculate V., from the volume of CO2 at high pressures. The swelling factor was calculated as where V, is the volume of the C0,-

By P. C. Johnson, B. A. Stein

This paper describes a study of the effects of combined heat treatment and explosive loading on the mechanical properties of high-strength steels. nis program investigated two distinct areas: 1) the effect of shock waves, without gross irreversible defmmution, on a 3-Cr steel at various stages of heat treatment; and 2) the effect of rapid deformation (explosive forming) on H-11 and D6-AC steels in the metastable austenitic state. The mechanical properties of these steels were improved, in some cases markedly, as a result of these treatments. ,AUSFORMWG, which requires the plastic deformation of metastable austenite, is a process which can appreciably improve the properties of selected alloy stee1s.l,2 The Ausform process significantly increases the strength of these steels without decreasing their ductility. The properties at high temperatures are also improved through a change in the response of the steels to tempering. Although the mechanism by which ausforming alters the properties of these steels is not fully understood, it appears that the dislocation arrays produced by deformation of the metastable austenite influence the structure of the martensite on subsequent transformation. This, in turn, affects the strength, ductility, and tempering response of the martensite. This research used chemical explosives to deform steels at various stages in their heat treatment in order to improve the properties of these steels. The explosive energy is used in two ways; 1) high-pressure shock waves are propagated through the steel to produce extensive microscopic shear strain without causing a large irreversible change in shape, and 2) explosive energy is used to cause extensive macroscopic plastic strain in the metastable austenitic state (explosive forming). I) AUSFORMING WITH INTENSE SHOCK WAVES The steel used in this phase of the research was an alloy having a nominal composition 0.43 pct C, 3.0 pct Cr, 1.5 pct Ni, and 1.5 pct Si. The steel was subjected to intense shock waves in three conditions: 1) in the metastable austenitic state, 2) in the tempered mar tens itic state, and 3) in the tempered martensitic state after ausforming by conventional techniques. The specimens were in the form of disks 2.75 in. in diam and 5/16 in. thick. These were incorporated into a specimen assembly consisting of two disks pressed into a 5 by 5 by 1 in. block of stainless steel, Fig. 1. Spalling (or scabbing) is confined to the front disk. The specimen is protected from oxidation and decarburization by the surrounding metal. The temperature of the assembly is monitored by a thermocouple inserted into one side of the stainless steel block. The assembly is positioned over an oil reservoir which serves both as a means of catching the disks and as quenching medium for the disks shocked under ausforming conditions. Plane shock waves are introduced into the assembly by a metal driver plate impacting the top surface of the block. The driver plate is accelerated by a chemical explosive sheet supplied by E. I. du Pont de Nemours & Co. All the specimens were subjected to plane shock waves having a peak pressure of approximately 430 kbar. The pressure is that quoted by G. E. Dieter for the plane wave generator used in this work.' The driver plate used was 1/4 in. thick, so that the initial pulse was essentially a l/2-in.-wide square wave. The attenuation of the peak pressure during the subsequent 1/4 in. is estimated to be less than 5 pct. The shock front induces a temperature rise, a portion of which is irreversible. Rough estimates (+25 pct) of this temperature rise have been made for iron shocked at room temperature.4 For a 500-kbar shock wave, the temperature rise in the shock front is about 700°F, and is held for a time of the order of microseconds. The irreversible temperature rise, which remains after the shock wave passes, is about 450°F.4 The disks are quenched to room temperature within a few seconds of the shock treatment. It should be emphasized that the temperature rises given above are estimates for pure iron at room temperature, and are not necessarily true for the tests made in this work. The disks shocked at temperatures in the metastable austenitic range were austenitized in the stainless steel assembly in a furnace protected from the firing area. The assembly was removed from the furnace and placed over the recovery reservoir. The plane wave generator was then positioned and

Jan 1, 1963

By E. T. Turkdogan, L. S. Darken

Calcium ferrite melts were equilibrated with sulfur and oxygen-bearing gases at temperatures within the range 1290°C to 1620°C. The results show that at oxygen partial pressures below 10-4 atm the sulfide-reaction occurs and at higher oxygen pressures the sulfur dissolves in the melt principally as sulfate ion. It is also observed that when the product increases, sulfate ions are converted to pyrosulfate ions and the results permit the evaluation of the pyrosulfate/sulfate ratio. It is shown that the ratio y CaSO,/rCaO increases with decreasing concentration of calcium oxide in calcium ferrite, silicate and aluminate melts. Indications are that oxy-acids, e.g. silica, alumina and ferric oxide, increase yCaS0,. A few experiments were carried out within the sul-tide range and the results are in accord with those obtained by other investigators on aluminate and silicate melts. BECAUSE of the industrial importance and theoretical interest, many investigators have studied the reactions between molten oxides, silicates or alumi-nates, and gases containing oxygen and sulfur. The early work reviewed by Schenckl and studies made by Bardenheuer and Geller2 indicates that solution of gaseous sulfur in an oxide melt resulted in the replacement of the oxide ions by the sulfide ions. Measurements made by Grant and Chipman3 on the equilibrium partition of sulfur between molten iron and complex silicate melts also demonstrated that, for a given temperature and silicate composition, the distribution of sulfur between slag and metal increased with decreasing oxygen content of the metal. Fincham and Richardson4 studied the effects of temperature and partial pressures of sulfur and oxygen on the solubility of sulfur in simple silicate and alumino-silicate melts. They observed that at oxygen partial pressures below about 10-5 atm sulfur in the gas dissolved in the melt as sulfide ions, replacing an equal number of oxide ions of the melt. At oxygen partial pressures higher than 10-3 atm, sulfur entered the melt as sulfate ions. Similar studies were made by St. Pierre and Chipman5 using calcium ferrite and calcium silico-ferrite melts. The experimental data presented in this paper were obtained in this Laboratory about 10 years ago; this is the first formal presentation although a preliminary report was given previously.6 In each of these experiments, a pure synthetic CaO-Fe2O3 melt in a platinum crucible was equilibrated with a gas mixture (SO2-O2, SO,-air, SO2-CO, or SO2-CO2-CO) at a temperature ranging from 1296°to 1620°C. The experimental technique was essentially the same as that reported by Darken and Gurry,7 the main difference being that the atmosphere in the reaction chamber contained sulfur dioxide together with oxygen, or carbon dioxide-carbon monoxide

Jan 1, 1962

By Richard H. Jahns

GRANITIC pegmatite deposits are the chief source of commercial feldspar, sheet mica, beryllium, tantalum-columbium, and lithium minerals, and certain types of kaolin. They also have yielded significant quantities of cassiterite, gems, scrap mica, molybdenite, tungsten minerals, uranium-thorium and rare-earth minerals, and zircon, either directly or as the sources of placer deposits. The output from pegmatite mines in the United States is small as compared to other mineral products in terms of bulk or value, and much of it comprises minor metals and nonmetals. Nevertheless, pegmatite minerals play a vital part in domestic industrial economy, particularly in the ceramic and electrical industries. Numerous special purpose uses also are important, even though they require small quantities of raw materials. Never was United States dependence upon pegmatite mining more clearly emphasized than during World War 11, when greatly expanded demands and uncertainties of foreign sources of supply caused much concern. Such commodities as beryl, tantalite, and sheet muscovite remained high on the critical list for months at a time, and for some minerals there was a real struggle to achieve and maintain a favorable ratio of supply to demand. Satisfactory stock piles of certain sizes and qualities of sheet mica, for example, were not built up until late in 1944, when wartime requirements already had begun to level off or even to decrease. Production of all the strategic pegmatite minerals from domestic deposits during World War I1 constituted only 10 pct or less of the total domestic consumption of these minerals, but the importance of this contribution should not be minimized. Domestic production often represented the difference between increase and further reduction of existing stocks of commodities already in seriously short supply, and in the early stages of the war it was the only assured source if imports were cut off. During the recent war period, the U. S. Geological Survey carried on a program of pegmatite studies in the New England and Southeastern States, in the Black Hills area of South Dakota, in the Rocky Mountain region of Wyoming, Colorado, and New Mexico, and in various parts of Washington, Idaho, Utah, Nevada, Arizona, and California as shown in Fig. 1. Several papers and reports already have appeared as an outgrowth of this work,'-= and others are in preparation. This paper outlines some results of data obtained by the writer during the period 1942 to 1946, when he was engaged in studies of pegmatites in the Southeastern, Southwestern, and Rocky Mountain States. Beryllium Minerals Beryl is the present commercial source of beryllium metal and beryllium compounds, which are used in ceramics, in the preparation of X-ray tubes and fluorescent lamps and screens, in special processes of paint and textile manufacture, and in the optical systems of some electrical instruments. The metal also is used in nuclear physics, chiefly as a source of neutrons. Beryllium is alloyed with aluminum for certain light-metal uses and is a constituent of some nickel and iron alloys. Currently the chief demand, however, is for copper-base alloys, which are exceptionally resistant to fatigue and wear, are responsive to hardening treatments after

Jan 1, 1952

By Raymond B. Ladoo, C. A. Stokes

This paper summarizes the economic problems of the industrial mineral industries which are essentially different from those of the metals and the fuels. Failure to understand and evaluate such factors as markets, place value, and substitutions of one mineral for another may be disastrous. The engineer should be as responsible for profitable operation as he is for technical efficiency. The Raw Materials Survey of Portland, Oregon, is described.

Jan 2, 1950

By F. Kurata, P. C. Davis, T. L. Gore

An experimental method and apparatus for the study of the low-temperature phase and volumetric behavior of volatile mixtures are described. The phase diagrams, including the critical points, and the volumetric behavior of a natural gas and a mixture of the natural gas with methane at temperatures from -40°F to -200°F and pressures to 1.200 11si are givrn. INTRODUCTION Knowledge of the phase and volumetric behavior of mixtures of the light hydrocarbons at low temperatures is becoming increasingly important as interest in low-temperature separation processes increases. Distillation at low-lemperatures has been used for some time to recover ethane and ethylene from natural gas and refinery gas for petrochemical uses. Removal of excess nitrogen from natural gas by distillation has been proposed as a means of increasing the capacity of gas transmission lines and of improving the marketability of the gas.1,2 Evaluation of the latter process has been hampered, however, by the scarcity of data from which the phase behavior of natural gases at low temperatures might be predicted. While existing correlations of vaporization equilibrium constants may be used to predict the behavior of such mixtures at lower pressures, high-pressure computations often require knowledge of the location of the critical point of the system involved. Although correlations have been developed for the prediction of the critical temperature and pressure of certain types of hydrocar-bon systems, they do not apply to very volatile systems such as nitrogen-bear-ing natural gases. This paper describes the initial stages of an investigation of the low-temperature behavior of a numher of natural gases and other gases of commercial interest. The experimental method and apparatus are described. and the phase and volumetric behavior of a natural gas and a mixture of the natural gas with methane are presented. PREVIOUS WORK The published low-temperature vapor-liquid equilibrium data for hydrocarbons and mixtures of hydrocarbons with nitrogen and helium are listed in Table I. Most of these data are for binary systems, and the data of Stutz-man and Brown" at 100 psi are the only data on a natural gas. The data of Bloomer and Parent3 on the methafie-nitrogen system, which have been phblished since this study was completed, are a valuable addition to the knowledge in this field. Prior to the publication of these data the only published critical point data on systems having critical temperatures below the ice point were those of Ruhemann.1 on the methane-

Jan 1, 1952