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By J. H. Smith, H. W. Paxton

ALTHOUGH many structural and kinetic investigations have been made for alloys of iron and nickel, only meager data exist from thermodynamic investigations. The purpose of this note is to estimate the free energy of the Fe-Ni solid solutions from thermodynamic data available for ternary alloys containing iron and nickel. The lack of a description of the thermodynamic behavior for the Fe-Ni system has required the structural and kinetic analyses of the system to assume some form of solution behavior, usually regular, e.g., the mar-tensite transformation analysis of Kaufman and Cohen, 1 consistent with the limited thermodynamic data. Indications that this system could exhibit ideal solution departures might have been suggested by the large deviations from additivity rules observed in the density and lattice-parameter measurements of Jette and Foote2 who interpreted this in terms of possible solute-solvent interactions. Later Turkdogan et al. 3 and more recently Ward and wright 4 found a minimum in the graphite solubility in liquid Fe-Ni solutions near the concentration of FeNi3 with deviations from linearity persisting at all concentrations. This was interpreted by Ward and wright4 to indicate negative heats of solution and was suggestive of short-range ordering. The infinitely dilute activity coefficient of carbon (?oC) was also observed by smith5 to pass through a maximum near the FeNi3 concentration in Fe-Ni solid solutions. Recent investigations of the liquid solutions over the entire concentration range by Zellars et a1.' and Speiser et a1.," using vapor-pressure determinations, revealed both negative departures from Raoult's law and a nonregular solution behavior. The solid alloys have been studied by Oriani 8 and Kubaschew-ski and von Goldbeck6 employing gaseous H2/H2O equilibria with Fe and FeO. Both investigations were in substantial agreement, indicating very small departures from ideality. However, Oriani observed the formation of Fe3O4 (instead of FeO) at XFe= 0.441 which severed the equilibrium and precluded experimental investigation of the nickel-rich alloys. Heat-capacity and heat-content measurements have been evaluated by Montgomery10 and found generally unsatisfactory for gleaning thermodynamic information. This is due to the unknown final states of the alloys caused by the interference of the martensite transformation on cooling iron-rich concentrations and superlattice formation, magnetic transformation, and the varied heat treatments used by investigators of nickel-rich concentrations. As an alternative to the experimental difficulties, indirect estimates of the solid-solution behavior have been made by Fleischer and Elliott11 and Smith et a1.12 From their measurements of the solubility of Fe-Ni alloys in liquid lead, Fleischer and Elliott calculated the nickel activity (aNi) (and integrated for aFe) by assuming: 1) liquid lead has no solubility in solid Fe-Ni alloys, 2) Henry's law is obeyed throughout the liquid lead-rich phase (0— 12 at. pct Nil, and 3) Henry's law constant is independent of relative iron and nickel concentrations. The estimate of Smith et a1.12 was obtained

Jan 1, 1964

By R. A. Swalin, B. W. Roberts

ONSIDERABLE controversy has centered about the existence of an order-disorder transformation in alloys in the composition vicinity of 75 atomic pct Ni and 25 atomic pct Cr. All the evidence to date for such a transformation is of a rather indirect nature, since direct X-ray confirmation is difficult to obtain as a result of the small difference in X-ray scattering factors between nickel and chromium. As a result, superlattice lines would be very faint if present. Several investigators1-5 have observed anomalies in the electrical resistivity vs temperature curves of alloys in the vicinity of 25 atomic pct Cr. The observed change is characterized by a rather broad resistivity peak at about 540°C. A discontinuous drop in resistivity is normally associated with ordering. However, Taylor and Hin-ton4 have rationalized that the discrepancy could conceivably be caused by changes in the Brillouin zones upon ordering. The same investigators measured the specific heat as a function of temperature and have also observed anomalies in the vicinity of 540°C. Nordheim and Grant5 have proposed, because of the absence of superlattice lines and the absence of a discontinuity in the resistivity vs temperature curve, that long-range order is improbable and that the results could be better explained by short-range ordering. To date, however, the question has not been resolved satisfactorily. Neutron diffraction techniques provide a method for partially resolving the question since nickel and chromium have considerably different atomic scattering factors in the case of neutrons and, therefore, superlattice peaks, if ordering occurs, should be readily discernable. The results of a neutron diffraction investigation* coupled with a dilatometric in- vestigation are reported here. An alloy containing 28.0 atomic pct Cr was prepared from carbonyl nickel and electrolytic chromium in the form of a 1-in. diam x 10-in. ingot. Melting was done in an alumina crucible and casting in a graphite mold. The ingot was homogenized at 1250°C for seven days, after which a 5-in. long piece was cut into shavings in order to obtain a suitable neutron diffraction sample. Hardness samples and samples suitable for dilatometric analysis (% in. diam x 2 in.) were prepared from the remainlng piece. The neutron diffraction sample, along with a hardness sample, was annealed at 501°C for seven days, at which time the temperature was lowered to 479°C and held at this temperature for twenty-four more days. The hardness was observed to increase from 133 to 147 Vhn during the course of the annealing treatment, in qualitative agreement with Nordheim and Grant." Neutron diffraction traces taken at room temperature and at 42 °K are shown in Fig. 1. The insert shows the trace taken at room temperature with short counting times and thus only fair statistical accuracy. No evidence for superstructure reflections of Cu3Au-type ordering is observed. The statistical accuracy of the 4.2°K trace was improved by using longer counting periods. Several weak intensities are observed at small angles, including an aluminum reflection from the cryostat assembly and a very

Jan 1, 1958

By R. H. Fillnow, D. J. Mac

IT has been demonstrated that alloys in systems structurally analogous to steel undergo reactions during heat treatment similar to those of steel, and yet very little work has been done on such systems, particularly from the standpoint of isothermal transformation. The literature shows that most of the isothermal work has been done on copper-alu-minum alloys.'-3 One paper has been reported on a eutectoid copper-silicon alloy,' and one on iron-nitrogen alloys.' There are no published reports of previous investigations on the isothermal transformation of a eutectoid beryllium bronze. At least two papers have been reported on isothermal age-hardening phenomena in beryllium-copper alloys of lower beryllium content.5,6 No information on eutectoid transformations in this alloy is given in Rimbach's book, "Beryllium." ' This paper reports the results of an investigation on the isothermal transformation characteristics of a eutectoid beryllium bronze. Materials Used and Procedure The eutectoid beryllium bronze used in this investigation was centrifugally cast at the Ampco Metal Co., Inc.. Milwaukee. Wis. A master beryl-lium-copier alloy, purchased from the Brush Beryllium Co., was used to make the beryllium addition to the copper. The alloy was melted under a protective carbon cover and Centrifugally cast into a graphite mold preheated to 920°F. Some trouble with segregation of beryllium in the melt was encountered but was eliminated by violent stirring during melting and pouring. Since very thin .specimens were used for the various heat treatments, only one casting of the four prepared was necessary for the complete isothermal study, thus eliminating any discrepancies caused by a change in composition. The analysis of this casting was 94.035 pct copper and 5.965 pct beryllium. A slight trace of iron was found. The castings were sawed into specimens approximately 3/32 in. in thickness. The specimens were first given an "austenitizing" heat treatment at 788°C, well within the single phase beta region, in a vertical tube furnace. The specimens were then quenched individually into an adjacent molten salt bath and held there for a definite time, after which they were quenched into water at room temperature. Temperature was held to ± 2°C in the salt bath. No homogenizing treatment was given the specimens other than the soak at 788°C. Despite the fact that this was a cast alloy, no evidence of segregation or coring was found in the microstructure of any specimen, either as cast or as heat-treated. Upon completion of the heat treatment, the speci-mens were subjected to metallographic examination

Jan 1, 1951

By E. L. Spain

The deposits described in this paper occur over much of Wayne County and in the southeast portion of Hardin County, Tennessee, and in the northeast and northwest portions of Mississippi and Alabama respectively. The presence of tripoli in this region has been known for some time and descriptions of various occurrences in Tennessee have been made by Jewelll and Miser2, while Hilgard3, Lowe4 and Logan5 have treated the deposits that occur in the adjacent portions of Alabama and Mississippi, but there has not been a 'general survey of the entire field summarizing completely the geology of the deposits with respect to their origin and stratigraphic relationships. During 1934, while engaged in surveys of mineral resources through this region for the Tennessee Valley Authority, the writer collected data with this in mind, and has assembled them in this report. He is indebted to H. S. Rankin and N. A. Rose, of the Tennessee Valley Authority Geology Division, for field assistance. Location of Tripoli Deposits Fig. 1 shows the locations of deposits of tripoli in a long belt that extends from northeast Wayne County southwestward into northwest Alabama and thence passes into Mississippi, where the formations carrying it are finally covered by Cretaceous sand and gravel of the Mississippian Embayment. Occasional deposits occur also in the southeastern corner of Hardin County, Tennessee. While tripoli is found at nearly all points along this axis where the related formations are exposed, the largest deposits are grouped about three different centers. Waynesboro-Collinwood District.—In the area between Waynesboro and Collinwood, in Wayne County, Tennessee, tripoli of various grades outcrops in the valley of Green River and in tributary valleys on either side. This district is roughly 12 miles long in a northeast-southwest direction and has a maximum width of 5 miles at its northern end. Exposures are found in road cuts, highway chert pits, in the beds of some of the streams, and on hillsides. The greatest number of high-grade

Jan 1, 1938

By C. R. Austin

THE investigation described in this paper deals with the development of high-temperature alloys of the Konel series over a considerable period of time at the Research Laboratories of the Westinghouse Electric and Manufacturing Co. The word "Konel" has been coined to designate a class of alloys which are essentially nickel-cobalt-iron with other elements added, usually in small quantities. Most of these alloys contain titanium, usually about 2.5 percent. The main consideration related to strength at high temperatures but the thermionic characteristics of the alloys was also of considerable importance. It is, however, with the mechanical properties at elevated temperatures that we are herein concerned. Much attention has also been devoted to their age-hardening characteristics. There is little need to stress the utilitarian aspect of this subject, as it has been discussed frequently. Alloys exhibiting superior properties at normal or elevated temperatures rapidly find many suitable applications. There may be some question, however, as to what constitutes a "superior alloy, " or an alloy that may have good service possibilities at high temperatures. The problem is complex and various means have been employed to predict the useful life that may be expected of a material. In recent years the "creep limit" has been used as the best means of evaluation. Such tests necessarily are prolonged and hence collection of data is very slow. In a general survey of many alloys therefore the creep test is not desirable and recourse must be had to much shorter time tests in order more rapidly to select alloys which appear to show promise. For this reason the present survey has been made using the high-temperature tensile test and a bend' test developed by Howard Scott.1 In the tensile test the conditions have been standardized for all tests, so that values obtained are at least comparable, one alloy with another, although the absolute values recorded merely indicate the mechanical properties at the given temperature under a definite rate of loading.

Jan 1, 1931

By C. F. Nagel

This paper is written primarily for those who are familiar with the processes mentioned but who desire a further insight into some of the fundamental principles. It does not give a complete description of the various practices employed in the working of aluminum and its alloys, but presents a few illustrations of the essential respects in which aluminum differs from other common metals, and emphasizes the controlling factors of the processes under consideration. Heat Treating Certain aluminum alloys are capable of having their mechanical properties greatly altered by a heat-treatment process. The degree of this irnprovement may be illustrated by some typical properties of dura-lurnin (Table 1). It is essential that the material be in the wrought condition in order to obtain rnaximum heat-treatment effects. In the case of duralumin, the process consists of heating the metal to a prescribed temperature and then quenching it. Immediately after quenching, the material is relatively soft though not as soft as in the annealed state. If allowed to stand at room temperature, the material changes, increasing in hardness and strength without loss of elongation, but at the expense of the plasticity. This action is very rapid at first, gradually diminishing in intensity and to all practical purposes being completed in about four days. This process of hardening is termed

By E. L. Spain

The deposits described in this paper occur over much of Wayne County and in the southeast portion of Hardin County, Tennessee, and in the northeast and northwest portions of Mississippi and Alabama respectively. The presence of tripoli in this region has been known for some time and descriptions of various occurrences in Tennessee have been made by Jewelll and Miser2, while Hilgard3, Lowe4 and Logan5 have treated the deposits that occur in the adjacent portions of Alabama and Mississippi, but there has not been a 'general survey of the entire field summarizing completely the geology of the deposits with respect to their origin and stratigraphic relationships. During 1934, while engaged in surveys of mineral resources through this region for the Tennessee Valley Authority, the writer collected data with this in mind, and has assembled them in this report. He is indebted to H. S. Rankin and N. A. Rose, of the Tennessee Valley Authority Geology Division, for field assistance. Location of Tripoli Deposits Fig. 1 shows the locations of deposits of tripoli in a long belt that extends from northeast Wayne County southwestward into northwest Alabama and thence passes into Mississippi, where the formations carrying it are finally covered by Cretaceous sand and gravel of the Mississippian Embayment. Occasional deposits occur also in the southeastern corner of Hardin County, Tennessee. While tripoli is found at nearly all points along this axis where the related formations are exposed, the largest deposits are grouped about three different centers. Waynesboro-Collinwood District.—In the area between Waynesboro and Collinwood, in Wayne County, Tennessee, tripoli of various grades outcrops in the valley of Green River and in tributary valleys on either side. This district is roughly 12 miles long in a northeast-southwest direction and has a maximum width of 5 miles at its northern end. Exposures are found in road cuts, highway chert pits, in the beds of some of the streams, and on hillsides. The greatest number of high-grade

Jan 1, 1938

By H. B. FERNALD

THE first year to which the Revenue Act of 1936 has applied is now passed. It is appropriate to try to give some calm thought to the plan of Federal income taxation as now imposed and what it will mean to the business and industry of the country if this plan of taxation is continued unchanged. Whether or not we like to pay these taxes is beside the point. Taxes are high and may be expected to be high for many years. The important question is whether the taxes to be imposed will destroy or injure business enterprise and development, and, in so doing, lower the standards of employment, living, comfort, and welfare of our people. The power to tax is the power to destroy. That destruction may come suddenly as a cyclone, or slowly as dry rot. What, if any, features are there in the present plan of Federal income taxation that have these destructive tendencies? A few of the points follow that seem to call for consideration.

Jan 1, 1937

By H. R. Hoffman

SINCE slag is a necessary product of the reactive oxygen additions necessary to the present-clay quality steelmaking, the study of the control of its volume is being attempted. With other varying factors that may affect the volume of slag kept as nearly constant as possible, the object of this investigation is to determine what effect the one factor of varying the amounts of iron-ore additions and the time of the additions may have upon the volume of slag in producing an acid electric steel heat.

Jan 1, 1947

By A. U. Seybolt

Experiments on both suljidation and hot corrosion have been carried out using ternary Ni-Cr-X alloys and commercial nickel-base superalloys. It has been shown that lhere are certain micro structural similarities between sulfidation using H,S/H2 mixtures and hot corvosion using Na,S04 in "crucible" experiments or hot corrosion tests using a flame tunnel apparatus. It is proposed that two key processes in the hot cowosion process are: 1) formation of chromium sulfides which deplete the alloy matrix, and 2) oxidation which can be accelerated because of chromium depletion. Other processes play an important role in the hot corrosion process, such as accelerated oxidation attack due to the presence of a N& S04 or N&SO,- NaC2 film which inhibits the formation of a protective external oxide scale. However, this latter phenomenon was not studied in this work. THE term hot corrosion has come to mean a combination of sulfur and oxygen attack on nickel-base or cobalt-base superalloys used as gas turbine blades or partitions. This attack can be initiated by any combustion process in air involving fuel containing sulfur if the sulfur level is sufficiently high. Levels of 5 pet SO2l for example, in the combusting gas have been observed to produce hot corrosion attack on nickel-base alloys. The important immediate corroding medium in aircraft gas turbines, however, has been established to be Na2S04, formed from reaction between NaCl from sea air and sulfur in the fuel.' The Na2S04 concentrates the sulfur sufficiently so that superalloy parts heated in the range 1400" to 1900°F can become sulfided by reducing the Na2S04 film which forms on the parts, and this reaction allows sulfur to gain access to the alloy. The sulfur thus released diffuses into the superalloy and forms primarily chromium sulfides of various compositions, but frequently Cr2S, has been identified. Figs. 1 and 2 show the morphology typical of hot corrosion of a cobalt-base superalloy X-45 (25 Cr, 10 Ni, 7.5 W, 0.25 C) and a nickel-base alloy, Udimet 500 (19 Cr, 19 Co, 4 Mo, 3 Ti, 2.9 Al, 0.07 C). Both alloy samples were subjected to the same hot corrosion conditions: 616 hr at 1600°F in a combusted 2.9 pct S distillate oil containing 125 ppm Na as NaC1. It will be noted at once that the nickel-base alloy is much more severely attacked. The depth of corrosion is much greater and the number and size of the sulfides present are much greater. Both alloys show a duplex oxide scale, which is more noticeable in the X-45 alloy. The external scale is probably a spinel in both cases, with CrQ3 lying next to the alloy. Many investigators1 -"ve been concerned with hot corrosion phenomena, but there has been a lack of unanimity of opinion as to the details of the hot corrosion mechanism. More than one definition of hot corrosion is possible. Some investigators con- sider as a measure of hot corrosion only the weight gain due to an accelerated oxidation. However another point of view is that the total depth of affected alloy may be used as a measure. While it is recognized that surface oxidation attack is greatly accelerated by the presence of salts like Na2S04 or Na2S04-NaC1 mixtures, sulfur penetration into the alloy also undoubtedly produces very important effects. The region of sul-fide penetration which is so prominent in Fig. 2 is one of the outstanding characteristics of hot corrosion. For highly stressed parts, such as first-stage buckets, this sulfur-penetrated region can be more significant in mechanical property loss than the reduction of cross section produced by the formation of the massive external scale. In addition, evidence will be presented that this sulfided region can be less resistant to subsequent oxidation attack. Since it appears that the sulfided region below the surface oxide scale plays an important role in the overall corrosion process,

Jan 1, 1969

By AIME AIME

THE Board of Directors of the Institute has authorized the appointment of a committee to draw up rules of procedure under which awards can be made from time to time to petroleum engineers for outstanding contributions to the art of finding and producing oil and gas. These awards will 11e sponsored by the Petroleum Division and are the first recognition by any professional society of outstanding achievement in "oil mining." They will be in the form of either a gold medal, scholar- ship, or other suitable prize. The awards will be financed from the income of the Anthony F. Lucas Memorial Fund, which was started about fifteen years ago, shortly after' his death, by admirers of Captain Lucas.

Jan 1, 1936

By A. G. Weber, R. L. Ledbetter, A. L. Hicks

A procedure which makes use of both analog and digital computers has been developed for predicting the pressure-production behavior. of water-drive reservoirs. The electric analyzer is used for matching the past pressure and production history of the reservoir and inferring the physical characteristies of the aquifer. When the history has been matched, a .set of base curves called influence functionce" are derived and the future behavior of the reservoir is calculated from these curves. INTRODUCTION Electric analog methods are particularly well-suited for complex water-drive problems. Like all other methods of analyzing water-drive reservoirs, however, analog methods are subject to certain limitations. One of the more obvious and serious of these results from inaccurate or insufficient knowledge about physical characteristics of the reservoir and aquifer. However, it is not insurmountable because the unknown characteristics can usually be inferred from the reservoir's previous behavior. Simons and Spain have shown that even with scant reservoir data and limited production history, electric analyzer studies can provide useful and reliable results. Aside from this limitation on analyzer predictions, the main disadvantage has been lack of a technique for keeping predictions abreast of latest production forecasts. Pressure behavior of a reservoir depends on the rate at which fluid is withdrawn; it is therefore necessary to specify the future withdrawal schedule before the future pressure behavior can be calculated. Conventionally, the electric analyzer predicts pressure behavior for a specific production schedule. If this schedule is abandoned in favor of some new one, as is frequently the case, either the study must be rerun or results adjusted in some manner. The usual procedure is to predict pressures for several different forecasts covering a wide range of production rates. Pressures for specific rates other than those studied can then be approximated by interpolating between the analyzer predicted curves. However, reliability of this type of prediction is doubtful. This paper describes a technique for predicting future behavior of water-drive reservoirs that retains all advantages of electric analyzer analysis and eliminates the main disadvantage. That is, the analyzer is used conventionally to infer unknown reservoir parameters from the pressure history, but not to predict the future behavior directly. Instead, a derived set of base curves, called influence l'unctions, can be used to calculate future behavior for any production schedule.

By H. W. Gillett

WE hear much in these days about "tailor-made" steels. Farseeing executives have sensed the demand for metals of improved and special properties, with those properties deliberately built into the steel in order to fit it for a particular use or group of uses. They have set their metal-lurgists at work to produce what the customer needs, even though the tonnage required may not, at least at first, be great. As the metal-lurgists bring out such metals, the products are advertised and the customer becomes increasingly conscious that he no longer has to take "ready-made" steel as the only thing available, whether it fits his needs or not, but that there are plenty of steelmakers ready to serve his specific needs with a tailor-made steel. Of course this is nothing new in the realm of rather highly alloyed steels to be heat-treated. The automotive industry demanded and got such steels long ago. Indeed, one could not design a modern car using only non-heat-treated carbon steel, since an engine of present horsepower would be so heavy that the gasoline required merely to lug the engine itself around would be absurd. Many different alloy steels and many different heat-treatments are required to produce the fine gradations of properties and the strength per unit weight that are needed in each particular part. Aircraft designers, of course, count a high strength-weight ratio in the materials used as Article I in their constitution, and they too, and in outstanding degree, require tailor-made alloys. Aircraft and automobiles may be considered as the tail coats and Tuxes of the metallurgical tailors. Nowadays there is also a demand for business suits, in the form of high-strength alloys to reduce dead load and so increase payload, all through the transportation industry. We hear most about weight-saving design and materials in respect to the railroads, with the spectacular new high-speed passenger trains and the prosaic freight car. The latter sounds especially sweet to steel-mill ears, because it means tonnage. While most of us think of these developments, and of the engineering acceptance of high-strength materials as "new," the fundamentals are of almost hoary antiquity. It is the widespread availability of a variety of materials and their general acceptance that are new.

Jan 1, 1936

By J. B. Austin

In considering so complex a process as the smelting of iron in the blast furnace, there is obviously no single method of calculating efficiency that gives a complete appraisal of the performance of the furnace in all its several functions; such a comprehensive view as is required to evaluate producing ability and manufacturing costs for a given furnace is obtained only by considering a group of efficiencies, each of which measures the performance of the furnace from a specific point of view. For instance, there is the rate of consumption of coke per ton of iron produced, which is probably the most frequently considered, and is certainly one of the most important of the group; there is the efficiency of recovery of iron charged; and there is the efficiency of utilization of energy, both chemical and thermal, in some respects related to the former two yet in other ways independent of either. In each of these cases, the calculation can be made on the basis of the actual input of material or energy, or it may be based upon a comparison with the minimum amount of material or energy that would be required by a "perfect" furnace; that is, an imaginary ideal furnace analogous to the perfect steam engine used in thermodynamic calculations, when this furnace is operating under optimum conditions. Moreover, the furnace itself can be considered either as an apparatus for smelting iron or, taking a somewhat less common point of view, as a gas producer yielding iron and slag as by-products. Some of these efficiencies are more useful than others, yet all are instructive; for a knowledge of them not only leads to good engineering practice from the standpoint of control but also discloses limits to possible improvement in performance and indicates the lines along which improvement is most likely to be profitable. Estimates of some of these efficiencies have appeared from time to time in the literature, but many of them are open to objection because they are based on data of uncertain accuracy or because they have been caleulated without due regard to the thermodynamic principles involved. Moreover, so far as the author is aware. no general survey of the blast furnace comparing its performance in all the aspects mentioned has been made.

Jan 1, 1938

By J. B. Austin

In considering so complex a process as the smelting of iron in the blast furnace, there is obviously no single method of calculating efficiency that gives a complete appraisal of the performance of the furnace in all its several functions; such a comprehensive view as is required to evaluate producing ability and manufacturing costs for a given furnace is obtained only by considering a group of efficiencies, each of which measures the performance of the furnace from a specific point of view. For instance, there is the rate of consumption of coke per ton of iron produced, which is probably the most frequently considered, and is certainly one of the most important of the group; there is the efficiency of recovery of iron charged; and there is the efficiency of utilization of energy, both chemical and thermal, in some respects related to the former two yet in other ways independent of either. In each of these cases, the calculation can be made on the basis of the actual input of material or energy, or it may be based upon a comparison with the minimum amount of material or energy that would be required by a "perfect" furnace; that is, an imaginary ideal furnace analogous to the perfect steam engine used in thermodynamic calculations, when this furnace is operating under optimum conditions. Moreover, the furnace itself can be considered either as an apparatus for smelting iron or, taking a somewhat less common point of view, as a gas producer yielding iron and slag as by-products. Some of these efficiencies are more useful than others, yet all are instructive; for a knowledge of them not only leads to good engineering practice from the standpoint of control but also discloses limits to possible improvement in performance and indicates the lines along which improvement is most likely to be profitable. Estimates of some of these efficiencies have appeared from time to time in the literature, but many of them are open to objection because they are based on data of uncertain accuracy or because they have been caleulated without due regard to the thermodynamic principles involved. Moreover, so far as the author is aware. no general survey of the blast furnace comparing its performance in all the aspects mentioned has been made.

Jan 1, 1938

By T. H. Alden

Using alternating tension-compression straining, the hardening of magnesium oxide single crystals was studied up to large stresses and strains. At 0.25 pct plastic strain amplitude, the hardening curve is approximately linear with slope 25,000 psi from the shear yield stress, 7 to 8000 psi, to 35,000psi. Above this stress, the slope decreases. The strain hardening behavior of MgO is considered qualitatively similar to that of metal single crystals. The relatively high stress attainable by strain hardening is associated apparently with the high yield stress on the cross-slip system, (001) <110>. Cleavage fracture during testing is uncommon. It is argued that the centers of high internal stress at glide band intersections, at which cracks tend to nucleate, are dispersed by cyclic strain. Special features of the glide band structure produced by cyclic strain and revealed by dislocation etch pits, support this view. Strain hardened MgO has mechanical properties greatly superior to the as-received material: yield stress, greater than 100,000 psi; elongation to fracture about 1 pct. A material is said to strain harden if the yield stress increases with an increment of plastic strain. This definition is usually applied for straining done in one direction, but is also applicable when the strain direction is periodically reversed, Fig. 1. For certain metal single crystals, data are available which permit a comparison of the hardening behavior for cyclic straining and for tension straining.&apos;-4 With certain qualifications, these data show that the same processes of hardening are operative in each type of test.5 Despite this fact, the importance of the technique is not immediately evident, although tension-compression studies of the common metals appear to suggest some deficiencies in theories of strain hardening developed exclusively on the basis of tensile tests. However, a recent observation suggests that the cyclic straining method may be very useful for studying semibrittle crystals in which large plastic strains are not accessible in unidirectional testing. The observation is that zinc crystals, when strained in tension-compression at -52°C, do not fail by cleavage at low stress (-500 psi)6 as they do in tension, but harden to a limiting stress of more than 5000 psi over a total plastic strain of about 600 pct.2 An important characteristic of the behavior of zinc crystals is the high stress, relative to the yield stress, attainable by strain hardening. By comparison, the hardening of aluminum single crystals tested by an identical technique saturates at 1100 psi. This difference is best explained by the cross-slip hypothesis of dynamic recovery.7,8 In zinc, cross slip is difficult because of the high yield stress for glide on planes other than the basal plane in the < 1120 > zone. The present work was undertaken in order to test whether these methods and ideas are applicable to other materials. Magnesium oxide single crystals, in common with most crystals of the rock-salt structure, deform plastically but fail by cleavage after a small strain when tested in tension. It was hoped that larger strains would be attained using tension-compression. There is, in addition, evidence 8a which shows that slip on the probable cross system, (001) < 110>, is difficult in magnesium oxide; it may therefore be possible to attain high stresses by strain hardening. 1) EXPERIMENTAL PROCEDURE Experimental methods used in this study were based in part on techniques reported in papers of Stokes, Johnston, and Li.&apos; MgO blocks, purchased from Norton Co., were used without further annealing. Specimens were cleaved to dimensions approximately 0.125 in. sq and 1 in. in length. The gage section, formed by chemical polishing, was sprinkled with 280 mesh silicon carbide particles in order to introduce fresh dislocations. The crystals were then cemented into cylindrical aluminum adapters and clamped in an Instron testing machine. One of two alternating straining programs was used. In the first, total cross-head travel was established and increased in steps after various numbers of cycles. In the second, a capacitance gage was used to directly measure the elongation of the specimen and the crosshead was controlled so as to keep the plastic strain amplitude constant. The straining was always symmetrical with respect to the initial, zero strain condition. While both procedures produce strain hardening, only the latter permits a measure of the total plastic strain so that hardening curves may be drawn. Constant plastic strain amplitude tests were done

Jan 1, 1963

By W. S. Steele

Vermiculite is a nonmetallic mineral of the mica family, probably related to biotite mica. Its occurrence has been noted at numerous places in the United States and in some foreign countries, but it can be said that vermiculite is of only moderately wide distribution. A laboratory and field survey of over 60 deposits in the United States by F. 1;. Schundler & Co., of Joliet, Ill., indicates that the purest deposit represented in this survey is on the property of the Zonolite Company at Libby, Montana The Zonolite Company is commercially active and the vermiculite it produces is sold as Zonolite. Hereafter, in this report, the word "Zonolite " will be used to designate the vermiculite produced by the Zonolite Company. Values given herein to Zonolite are peculiar to the vermiculite produced from the Zonolite Company&apos;s deposits. References to " vermicullite," are to he interpreted as covering the broad field covered by the Schundler survey. Composition and Characteristics of Vermiculite Vermiculite is an aluminum-nmgnesium silicate. The following typical analysis is published by the United States Bureau of Standards: silica, 41 per cent; iron oxide, 7; aluminum oxide, 18; magnesium oxide, 21; calcium oxide, 1; alkalis (sodium and potassium), 1; moisture, 11. Vermiculite breaks down into platelike formation in crushing and grinding operations. Its cleavage is basal. Crude, screened, dry Zonolit,e weighs between 80 and 90 Ib. per cubic foot; its specific gravity is 2.8 and its specific heat is approximately 2. The fusion point of Zonolit&apos;e is 2462" F. Crude vermiculite contains between 7 and 9 per cent of chemically combined moisture. The instantaneous introduction of crude Zonolite into an expansion furnace at a temperature of between 1800" and 2000" F. transforms the combined moisture into steam, which in an effort to liberate itself forces all explosive expansion of the platelike crude material

Jan 1, 1934

By E. T. Dumbles

Prof. Edward Orton, in his Report on the Occurrence of Petroleum, Natural Gas and Asphalt Rock in Western Kentucky, thus clearly states his ideas of the universal dissemination and rare accumulations of the bitumens:I "We need to bear in mind that the various members &apos;of the bituminous series are abundantly and almost universally distributed among the unaltered sedimentary rocks of the earth&apos;s crust. The valuable accumulations of these substances are rare, it is true, but one can scarcely go amiss&apos; of petroleum, asphalt or gas, at least in small quantities, among the stratified rocks that retain their original structure." Speaking of the Ohio valley, he adds: "A fifth of one per cent. of petroleum, if distributed through a thousand feet of rock, would make a total to the acre, or square mile far beyond any production that has ever been realized from the richest oil field, and -percentages of this amount are not only not rare to find, but are even hard to miss." Dr. F. W Clarke in his Data of Geochemistry (Bulletin No. 491, U. S. Geological Survey, 1911), discussing these views of Orton with similar views of T. Sterry Hunt and Szajnocha, says that they "lead to the conviction that the formation of bitumens is a general process and by no means exceptional. Wherever sediments are laid down, inclosing either animal or vegetable matter, there bitumens may be produced." The organic origin of the bitumens, including petroleum, Gas long been an accepted fact with nearly all geologists, but the method, place, and time of the transformation into petroleum or other bitumen is still under &apos;discussion. Dr. Orton says? "The statements now presented........bring before us two main views as to the origin of petroleum, viz.: " (1) Petroleum is produced by the primary decomposition of organic

Jan 1, 1915

By Herbert R. Mosley, Paul M. Tyler

STRATEGICALLY situated in almost the heart of the leading fertilizer- consuming area of the United States, Tennessee long has ranked second only to Florida as a phosphate-producing state. Since 1932 its share of the national output of phosphate rock has increased steadily, and in 1937 its production mounted to an all-time record. More significant even than the increase in tonnage are the forward strides in technology. The Tennessee Valley Authority&apos;s research program has led to quasicommercial operations using hydroelectric power to manufacture concentrated phosphatic fertilizer that is used to further the farmer education program designed to streamline the fertilizer business and halt the appalling waste of farm land by soil erosion. Even more stimulating to chemically minded imaginations is the production of elemental phosphorus by a private company that not only has succeeded in extracting it from the phosphate rock in electric furnaces but actually has contrived to capture it and to transport it safely in tank cars. New values have been created for low-grade phosphate deposits, and the economic life of reserves has been lengthened while the waste of former years goes back into the mills for recovery of its values by modernized methods. Tennessee&apos;s phosphate-mining industry dates from the discovery of blue rock in-lewis County in December 1893. Its known reserves are of the order of 101,500,000 tons, which compares with the production of 825,099 tons in 1937; that is, 21 per cent of the phosphate-rock output of the whole nation. The total output reported from 1894 until July 1, 1938, was approximately 19,000,000 tons. Official estimates of reserves are overly conservative and evidence submitted before a joint Congressional committee in November 1938 places "probable" reserves at more than 6,000,000,000 tons.

Jan 1, 1939

By Elmars Ence, Harold Margolin

A. J. Goldak and J. Gordon Parr (University of Alberta) —While we appreciate the difficulties involved in any investigation of this system, and we wish to congratulate the authors on their comprehensive efforts, there are several aspects of their paper that are not clear to us. 1) If the 6 phase is, in fact, isomorphous with Ti3Sn, it should not be designated Ti,Al. An 4B structure cannot be isomorphous with an ordered structure of the DO type. Anderko et al.&apos; suggested that the structure be called Ti3A1, and we believe this to be a more reasonable designation. The confusion is compounded when the authors designate the phase Ti3Al—yet the composition limits of this phase (according to their diagram) are approximately Ti,A1 and Ti,Al. Further, while Pietro-kowsky is said to have pointed out that the structure of the 6 phase is isomorphous with Ti3Sn, we understand that this was only a suggestion that was not confirmed. Margolin and Ence do not appear to have presented any evidence to support the suggested isomorphism. 2) In referring to the precipitation observed microscopically during the initial breakdown of high A1 a during quenching, the authors state that "such precipitation is not likely to be detected by Debye-Scherrer techniques". We suspect that if the precipitate was visible by optical microscopy, it must have at least one dimension of the order of 1 or greater, and would therefore be readily detected by diffraction techniques. 3) The authors state: "The basis for this suggestion (that 6 forms peritectically P + L—6) is the observation that the ,&apos;3 + 6 and 6 phase fields were

Jan 1, 1962