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PRECEDING chapters on thermochemistry, and the reactions in and between metal and slag phases in the bath of the furnace tend to emphasize the equilibrium or "static" conditions in the furnace and process, such as the total amounts of heat from fuel combustion or from certain bath reactions, the concentration relationships between slag and metal at the steady state for certain reactions, and the like. Such data are obtained essentially by means of the logic of thermo- dynamics, which helps to determine the energy change between initial and final states in a process as well as to define its equilibrium or steady-state condition, but which is not concerned with the rate of change in the process or with the mechanisms or path followed between initial and final states. These questions of just "how it works" and "how fast" belong to the kinetic aspect of any process; their answers are helpful in speeding up or slowing down and thus controlling intelligently its operation, and also to understand certain natural limitations which are especially important in many high-temperature processes. The kinetic aspects of interest here comprise mainly (1) the flow of gases through the furnace system, (2) the flow of heat in the system, and (3) the mechanisms and rate factors in the various chemical reactions. A really adequate discussion of the first two subjects would require at least three or four times the space available here; it has been tried, therefore, in this and the next chapter to outline but a few fundamentals necessary to an intelligent approach and to indicate some of the conditions of heat and gas flow more or less peculiar to the open hearth, since several good general discussions on these subjects may be found in the literature.(1) For the designer of open-hearth furnaces, the principles of gas flow are of paramount importance.(2,3,4,5) They are also important to the operation of the process, however, at least to the extent of a general qualitative picture of the movement of gases in the system, which is all that is attempted here.

Jan 1, 1944

By R. L. Rickett, N. C. Fick

Despite the large volume of literature on alloys of iron and silicon,' there is little published information dealing specifically with the constitution, at various temperatures, of the alloys containing less than 0.10 per cent carl~on and from 0.5 to 4.5 per cent silicon that are used extensively in the electrical industry. Because such information was needed by those engaged in the production of these alloys in sheet and strip form, the constitution nas determined of a series of commercial silicon steels containing 0.05 to 0.08 per cent carbon and 0.20 to 4.1 per cent silicon, over the temperature range 1300° to 1500°F. These alloys were all from regular production heats and of commercial quality. The results of the tests are given in Fig. I and for comparison the constitution diagram of iron-silicon alloys with 0.01 to 0.02 per cent carbon, taken from the literature, is also presented Material and Procedure All steels were hot-rolled to a thickness of 0.060 to 0.080 in. and used in this condition. Their chemical compositions, including over-all check analysis, and "center" analysis for carbon and silicon, are given in Table I. The so-called center analysis was determined on samples pickled to remove the outer surface and leave only the center third of the gauge thickness—the portion of the sample on which metallographic ratings were based. In most, but not all, of the alloys, slightly higher carbon was found at the center than when the whole strip was sampled; the two methods of sampling show relatively little difference in silicon. Two of the steels, A and E, contain relatively high phosphorus, while I and K are somewhat higher in manganese than the others. The procedure consisted essentially of heating specimens (about 1/16 by 3/8 by 3/4 in.), protected from oxidation or change in carbon content, at a temperature in the desired range and for a selected period, after which they were quenched in iced brine; the degree of transformation that had then occurred was determined by metallographic examination. The soaking periods were selected after preliminary investigation had shown that a con-

Jan 1, 1947

By N. C. Fick, R. L. Rickett

Despite the large volume of literature on alloys of iron and silicon,' there is little published information dealing specifically with the constitution, at various temperatures, of the alloys containing less than 0.10 per cent carl~on and from 0.5 to 4.5 per cent silicon that are used extensively in the electrical industry. Because such information was needed by those engaged in the production of these alloys in sheet and strip form, the constitution nas determined of a series of commercial silicon steels containing 0.05 to 0.08 per cent carbon and 0.20 to 4.1 per cent silicon, over the temperature range 1300° to 1500°F. These alloys were all from regular production heats and of commercial quality. The results of the tests are given in Fig. I and for comparison the constitution diagram of iron-silicon alloys with 0.01 to 0.02 per cent carbon, taken from the literature, is also presented Material and Procedure All steels were hot-rolled to a thickness of 0.060 to 0.080 in. and used in this condition. Their chemical compositions, including over-all check analysis, and "center" analysis for carbon and silicon, are given in Table I. The so-called center analysis was determined on samples pickled to remove the outer surface and leave only the center third of the gauge thickness—the portion of the sample on which metallographic ratings were based. In most, but not all, of the alloys, slightly higher carbon was found at the center than when the whole strip was sampled; the two methods of sampling show relatively little difference in silicon. Two of the steels, A and E, contain relatively high phosphorus, while I and K are somewhat higher in manganese than the others. The procedure consisted essentially of heating specimens (about 1/16 by 3/8 by 3/4 in.), protected from oxidation or change in carbon content, at a temperature in the desired range and for a selected period, after which they were quenched in iced brine; the degree of transformation that had then occurred was determined by metallographic examination. The soaking periods were selected after preliminary investigation had shown that a con-

Jan 1, 1947

By R. W. Raymond

The Mining Law of New Pork, contained in Title XI., Chapter IX., Part One of the Revised Statutes, is as follows: Section 1. The following mines are, and shall be, the property of the people of this State in their right of sovereignty : (1.) All mines of gold and silver discovered, or hereafter to be discovered, within this State. (2.) All mines of other metals discovered, or hereafter to be discovered, upon any lands owned by persons not being citizens of any of the United States. (3.) All mines of other metals discovered, or hereafter to be discovered, upon lands owned by a citizen of any of the United States, the ore of which, upon an average, shall contain less than two equal third parts in value of copper, tin, iron, and lead, or any of those metals. Sec. 2. All mines and all minerals and fossils discovered, or hereafter to be discovered, upon any lands belonging to the people of this State, are, and shall be, the property of the people, subject to the provisions hereinafter made to encourage the discovery thereof. Sec. 3. All mines of whatever description, other than mines of gold and silver, discovered, or hereafter to be discovered, upon any lands owned by a citizen of any of the United States, the ore of which, upon an average, shall contain two equal third parts or more, in value, of copper, tin, iron, and lead, or any of those metals, shall belong to the owner of such land. Sec. 4. Every person who shall make a discovery of any mine of gold or silver within this State, and the executors, administrators, or assigns of such persons, shall be exempted from paying to the people of this State any part of the ore, produce or profit of such mine for the term of twenty-one years, to be computed from the time of giving notice of such discovery, in the manner hereinafter directed. Sec. 5. No person discovering a mine of gold or silver within this State shall work the same until he gives notice thereof, by information in writing to the Secre-

Jan 1, 1888

By W. Klement

By quenching liquid alloys, single-phase solid solutions are obtained in the ranges 0 to 42.0 at. pct Co-Au and 0 to 15 and 75 to about 100 at. pet Co-Cu. Metastable solid solutions are also found in multiphase 42.0 to 49.0 and 69. 0 to about 100 at. pet Co-Au alloys. fie inability to achieve complete solid solubiliiies in Au-co and cu-co alloys is rationalized by a conszderation of the rate processes during cooling and solidification. Trends in lattice distortion and shifts in the compositions of the melting-point minima and critical points are discussed for the binary alloys of copper, silver, and gold with some of the transition metals of the first long period. By rapidly cooling alloys from the melt, a continuous series of metastable solid solutions can often be obtained for components of similar crystal structure which normally form eutectic systems.' The eutectic system Au-Co, Fig. 1, and the peritectic system Cu-Co, Fig. 2, were investigated in order to determine the extent of the metastable solid solutions attainable with the present technique.* EXPERIMENTAL PROCEDURES Most of the alloys were prepared by melting weighed quantities of the elements (purity greater than 99.9 pct) under hydrogen in alumina crucibles by means of induction heating. After reweighing, the alloys were cast under argon into 1 mm diam wires. However, it was not possible to prepare some of the Cu-Co alloys with the requisite homogeneity (over about 1 mm3) in this way. For these alloys, reduced powders (purity greater than 99.9 pct) were mixed for 12 to 48 hr, pressed into compacts that were sintered at 1000º to 1050°C for 6 to 48 hr under hydrogen, and then furnace-cooled. Alloy charges of a few mm3, cut from the cast wires or chipped from the sintered compacts, were heated to 1550º to 1600°C in 30 sec in an alumina insert held within a graphite support and then ejected by a pulse of helium onto a lightly polished copper strip on the inner periphery of a rotating wheel. The

Jan 1, 1963

By W. A. Ver Wiebe, E. G. Dahlgren

The year 1937 must be considered the most eventful one ever experienced in the development of oil and gas activity. Out of a total of 57 new pools discovered, 18 are apportioned to eastern Kansas and 39 to western Kansas. (For statistical purposes Kansas is divided along the meridian that separates ranges 3 E. and 4 E.) In addition to numerous longdistance extensions of the large Hugoton gas field of southwestern Kansas, two other gas pools were discovered in the area lying west of range 3 E. The 37 new oil pools in that area are to be found in 13 different counties, among which Rice heads the list with a total of seven oil pools and one gas pool. Ellis and Barton Counties both added six new oil pools, while Russell County follows in fourth place with four. Among eastern counties Butler heads the list with four new pools. Cowley arid Chautauqua each accounted for three new discoveries. The number of wells necessary to accomplish this result totals 2657, of which 1915 are oil wells and 128 gas wells. The initial production of the oil wells amounted to 2½ million barrels. Although most of the wells were drilled in proven territory, there was a good deal of wildcatting. The fact that 614 dry holes were completed emphasizes the ever-present risk attendant upon the efforts of pioneers. Some of the more venturesome spirits reached out to the counties farthest west in the state. An indication of the feverish excitement reached at times is recorded in the fact that no less than 600 drilling operations were in progress during one week in May, or the fact that over 100 new locations were staked during the second week in July. During one week in May, 65 successful oil wells were completed for an initial production of 68,000 barrels. Many drilling obligations came due during the year, and this perhaps accounts for the fact that one company had as many as 59 active operations at one time during September. Another evidence of great interest in oil possibilities in Kansas is furnished by the record of sales of oil properties, which in one case reached the high figure of about $3000 per acre.

Jan 1, 1938

By W. E. Keck, Paul Jasberg

THE flotative properties of the principal minerals in Michigan's potential iron ores have been investigated to develop methods of beneficiation for the ores. One of these minerals, magnetite, is of considerable importance as a source of iron. Study of its flotation was similar to that of hematite1, another iron mineral in these potential ores. The present research consisted essentially of: (1) a survey of the literature on magnetite flotation, (2) the preparation of pure magnetite, (3) the development of laboratory procedure and (4) flotation experimentation. Literature on Magnetite Flotation.-For the purpose of this discussion, the results of previous work on the flotation of magnetite can be summarized as follows. The mineral has been floated with pine oil2, and it has also been separated from synthetic mixtures with silicates by the use of the same reagent2. Magnetite and apatite in iron-ore slimes have been separated by flotation of apatite with sodium palmitate3. These data were utilized in the present investigation. Preparation of Magnetite.-The pure mineral was prepared from the magnetic-separator concentrate of an iron ore (obtained from the Witherbee- Sherman Corporation, Port Henry, N. Y.). This concentrate was slowly comminuted with laboratory rolls and pulverizer to pass 65-mesh and was then tabled several times. Tabling yielded a relatively coarse magnetite concentrate, tailing and slimes. The two latter materials were rejected insofar as the present work is concerned, and treatment of the magnetite (table concentrate) was continued by separating it into -65 + 200 and -200-mesh sizes. Separation of the sizes was made by first dry screening and then wet screening. The -200-mesh material was rejected to eliminate possible introduction of error into flotation This paper describes a part of a general investigation into the flotation of Michigan's potential iron ores. A comprehensive discussion of the status of these ores and of the reasons for research on their Rotation beneficiation is available in mimeographed form on application to the Michigan allege of Mining and Technology, Houghton, Michigan. Manuscript received at the office of the Institute Nov. 12, 1936. Printfed without author's corrections. Subject to revision.

Jan 1, 1937

By Clyde E. Williams

Estimates indicate a life of known Lake Superior iron ore reserves of 20 to 30 years. Although some believe the future ore supply will come from foreign sources and will be brought to interior points via the projected Great Lakes-St. Lawrence waterway, and others fear a displacement of the interior steel-producing districts to the Atlantic seaboard, the author has faith that American engineering skill will make possible the use of lean ores from the Lake Superior district. Three general types of Lake Superior ores and ore formations, that represent possible reserves and require beneficiation, are: (1) the wash ores of the western Mesabi range, (2) the partly leached hematitic formations, and (3) the oxidized but largely unleached iron formations. The total tonnage represented by (1) and (2) is not large, but the recovery of iron from present washery tailings would bring on the market the equivalent of nearly one million tons of wash ore, annually. Group 3 comprises the magnetic iron formation of the eastern Mesabi range, the hematitic formations including the taconites of the Mesabi range, and the iron formations of all the other ranges. These formations represent our future supply of iron ore. Their treatment requires intensive research because the bulk of the iron oxide and silica minerals exist in a finely disseminated condition. The possibilities of the adaptation of tables, oil flotation, and other processes warrant extensive study. Cheaper method of agglomeration of the concentrate is essential. Recent developments in better preparation and sizing of blast-furnace charges indicate that substitution of agglomerated ore for fines will increase furnace efficiency and output. If agglomerated beneficiated ore can be shown to rate a per-unit premium for iron contents over the base rate or a premium for structure, the payment of these would greatly assist in enlarging our iron ore supply. Since present methods of taxation of ore reserves, which encourage the rapid depletion of rich ores, will result in using up our rich ores and later on putting domestic producers at a disadvantage in competing with' foreign producers, it would seem highly provident to conserve our rich ores and to increase the use of beneficiated ores as soon as possible.

Jan 1, 1931

By L. W. Kemph, K. R. VanHorn

During the recent development of aluminum alloys for free-cutting screw-machine rod, it became desirable to know something of the solubility of lead and bismuth in liquid aluminum and in some aluminum alloys. The literature is not particularly helpful in supplying this information. These portions, therefore, of the constitutional relationships of aluminum-bismuth and aluminum-lead alloys were investigated by thermal analysis and by chemical analysis of samples taken from aluminum-rich melts in equilibrium with precipitated lead or bismuth. The solubility of lead and bismuth in some liquid aluminum-copper alloys was also investigated. Some consideration was also given to the solubility of these elements in solid aluminum. Among the earliest investigators of the aluminum-lead and alunlinum-bismuth systems was Wright,' who reported that melts of aluminum and lead formed two layers indicating limited liquid solubility. Under his conditions, the aluminum-rich layer was reported to contain 1.91 per cent Pb and the lead-rich layer, 0.07 per cent Al. Subsequently, Pecheau2 found that in aluminum-rich alloy melts with more than 10 per cent Pb three layers were distinguishable. He reported that the middle layer contained from 3 to 10 per cent Pb. He also found that the melting point of aluminum appeared to be lowered slightly by the addition of lead. Gwyer3 investigated these alloys and found evidence of a slight lowering of the freezing point of aluminum by the addition of either lead or bismuth. He found no evidence of solid solubility in either case and made no attempt to determine the liquidus curves. Hansen and Blumen-tha14 reported that the addition of lead distinctly lowered the solidification point of aluminum. They also found that bismuth lowered the melting point of aluminum. Guillet5 reported almost complete mutual immiscibility for the aluminum-bismuth alloys in the liquid state. Bohner6 examined the effect of various concentrations of lead and bismuth on the electrical conductivity of aluminum. He found decreases in conductivity on annealing at 500' C. as compared with the conductivity of the same alloys on annealing at 300' C.

Jan 1, 1939

By L. W. Kemph, K. R. VanHorn

During the recent development of aluminum alloys for free-cutting screw-machine rod, it became desirable to know something of the solubility of lead and bismuth in liquid aluminum and in some aluminum alloys. The literature is not particularly helpful in supplying this information. These portions, therefore, of the constitutional relationships of aluminum-bismuth and aluminum-lead alloys were investigated by thermal analysis and by chemical analysis of samples taken from aluminum-rich melts in equilibrium with precipitated lead or bismuth. The solubility of lead and bismuth in some liquid aluminum-copper alloys was also investigated. Some consideration was also given to the solubility of these elements in solid aluminum. Among the earliest investigators of the aluminum-lead and alunlinum-bismuth systems was Wright,' who reported that melts of aluminum and lead formed two layers indicating limited liquid solubility. Under his conditions, the aluminum-rich layer was reported to contain 1.91 per cent Pb and the lead-rich layer, 0.07 per cent Al. Subsequently, Pecheau2 found that in aluminum-rich alloy melts with more than 10 per cent Pb three layers were distinguishable. He reported that the middle layer contained from 3 to 10 per cent Pb. He also found that the melting point of aluminum appeared to be lowered slightly by the addition of lead. Gwyer3 investigated these alloys and found evidence of a slight lowering of the freezing point of aluminum by the addition of either lead or bismuth. He found no evidence of solid solubility in either case and made no attempt to determine the liquidus curves. Hansen and Blumen-tha14 reported that the addition of lead distinctly lowered the solidification point of aluminum. They also found that bismuth lowered the melting point of aluminum. Guillet5 reported almost complete mutual immiscibility for the aluminum-bismuth alloys in the liquid state. Bohner6 examined the effect of various concentrations of lead and bismuth on the electrical conductivity of aluminum. He found decreases in conductivity on annealing at 500' C. as compared with the conductivity of the same alloys on annealing at 300' C.

Jan 1, 1939

By G. V. Smith, R. F. Mehl

The decomposition of austenite in steels, because of its immerse practical importance, has been subjected to extensive study in recent years from the point of view of the mechanism of the process.1"3 Although much information has been acquired, a number of questions, principally of theoretical interest, remain. One is that of the atomic-crystallographic mechanism by which each of the various reaction products forms. The isothermal reaction products of the eutectoid decomposition in plain carbon steels (to which this study is restricted) have conveniently been classified in three general groupings—pearlite, bainite, and martensite. Of these several products, pearlite and martensite have been studied extensively, but bainite has received only scant attention. -As a result, the mechanism of the formation of pearlite and that of martensite are now fairly well understood while a great deal of uncertainty exists regarding bainite. Pearlite Pearlite forms from austenite by the precipitation of alternate platelets of cementite and ferrite, which grow into the austenite matrix.2--5 The rate of reaction may be described in terms of a rate of nucleation and a rate of growth.2.3 Mehl and Smith6 have attempted to determine the lattice relationships existing between the ferrite in pearlite and the' parent austenite. Using a pole-figure method of analysis, it was found that a limited number of ferrite orientations resulted from the decomposition of a single grain of austenite; it was not possible, however, to decide between two assumed ideal relationships, both of which appeared to account for the experimentally determined pole figure. It was definitely shown, however, that the relationship obtaining was quite different from that determined for the proeutectoid separation of ferrite.7 No attempt was made to determine the habit plane (matrix plane to which the precipitate lies parallel) of the pearlite lamellae. Belaiew8 earlier had stated that the number of directions assumed by the pearlite lamellae in a single grain of austenite was 12 (no details were given) and concluded wrong!:!, as Mehl and Smith6 have pointed out, that the lamellae delineate the {2I0} planes of ferrite.* Martensite It is known that martensite is a transiti0nal constituent of body-centered tetragonal lattice,' and that it forms suddenly

Jan 1, 1942

By R. F. Mehl, G. V. Smith

The decomposition of austenite in steels, because of its immerse practical importance, has been subjected to extensive study in recent years from the point of view of the mechanism of the process.1"3 Although much information has been acquired, a number of questions, principally of theoretical interest, remain. One is that of the atomic-crystallographic mechanism by which each of the various reaction products forms. The isothermal reaction products of the eutectoid decomposition in plain carbon steels (to which this study is restricted) have conveniently been classified in three general groupings—pearlite, bainite, and martensite. Of these several products, pearlite and martensite have been studied extensively, but bainite has received only scant attention. -As a result, the mechanism of the formation of pearlite and that of martensite are now fairly well understood while a great deal of uncertainty exists regarding bainite. Pearlite Pearlite forms from austenite by the precipitation of alternate platelets of cementite and ferrite, which grow into the austenite matrix.2--5 The rate of reaction may be described in terms of a rate of nucleation and a rate of growth.2.3 Mehl and Smith6 have attempted to determine the lattice relationships existing between the ferrite in pearlite and the' parent austenite. Using a pole-figure method of analysis, it was found that a limited number of ferrite orientations resulted from the decomposition of a single grain of austenite; it was not possible, however, to decide between two assumed ideal relationships, both of which appeared to account for the experimentally determined pole figure. It was definitely shown, however, that the relationship obtaining was quite different from that determined for the proeutectoid separation of ferrite.7 No attempt was made to determine the habit plane (matrix plane to which the precipitate lies parallel) of the pearlite lamellae. Belaiew8 earlier had stated that the number of directions assumed by the pearlite lamellae in a single grain of austenite was 12 (no details were given) and concluded wrong!:!, as Mehl and Smith6 have pointed out, that the lamellae delineate the {2I0} planes of ferrite.* Martensite It is known that martensite is a transiti0nal constituent of body-centered tetragonal lattice,' and that it forms suddenly

Jan 1, 1942

By J. Gurland, A. Gangulee

The cracking of silicon particles embedded in an aluminum matrix occurs progressively over the range of plastic deformation of the composite specimen. The fracture probability of the particles increases with increasing particle size and decreasing silicon contents. The crack orientation tends to be perpendiculay to the direction of the maximum tellsile strain. An example of a direct association between matrix slip and particle cracking is shorn. ALUMINUM-SILICON alloys of commercial compositions fail by ductile fracture in three stages:' I) initiation of cracks in the silicon particles, 2) growth of cracks into cavities, and 3) rupture of the aluminum matrix separating the cavities. The present work is concerned with the first stage: the initiation of cracks in the silicon particles. EXPERIMENTAL PROCEDURE Aluminum samples with 2.8, 6.1, 9.6, and 13.2 vol pet Si, respectively, were cast from commercial al- loys. Machined tensile specimens (2 in. gage length) were annealed in air at 1000°F for 100 hr, and then pulled at a strain rate of 0.025 per min. The grain size (average linear intercept) of the aluminum matrix was 0.24 and 1.6 mm in the 6.1 and 13.2 pet Si alloys, respectively. The particle size of silicon in alloys of one composition (6.1 pet Si) was varied by either modifying the castings with 0.15 pet Na or prolonging the annealing time. The average particle size was measured by linear and planar analysis, assuming spherical particles of uniform size. The particle sizes and compositions of all samples are tabulated in Fig. 8, together with the identifying symbols used in the graphs. The respective numbers of broken and unbroken silicon particles were determined from metallographically prepared longitudinal sections by counting a total of approximately 2000 particles per sample. EXPERIMENTAL RESULTS 1) Crack Initiation During Deformation as Function of Composition. Nominal stress-strain curves of four specimens of different compositions, but approximately equal particle sizes, are presented in Fig. 1. The fraction of broken particles, P (no. of broken particles/ total no. of particles), is shown in Fig. 2 as function of true stress and in Fig. 3 as function of nominal strain. The last point of each composition line in Fig. 2 rep-

Jan 1, 1968

By J. J. Ormsbee

Attempts at coal-washing have been made in the southern states during the last twenty years; but it is only within the last four or five years that the practice has become at all general. It might perhaps be claimed as one of the blessings derived from our departed " booms;" for, during their sway, the supply of coal of all qualities, good and bad, could not equal the demand; but, with the subsidence of the inflated demand, came imperative calls for fuels of better quality; and washers, previously regarded as luxuries, became necessities. Among those now in use in this section are representatives of the following types or classes: the trough washer; the jig washer; the percussive table; and those washers in which a constant upward current of water effects the separation. Without having full statistics, it is safe to say that there are in successful operation in the South more washers of the last class than of any of the others. The purpose of these notes is to present data with regard to the constructiOn, operation, and results of one of these current-washers, based mainly on the plant at No. 2 Slope, Pratt Mines, Alabama. The coal is mined from the well-known Pratt seam, having here an average thickness of 3 feet 6 inches. It has distinct cleavage-planes, and breaks in cuboidal lumps; is bright black in color, firm in structure, and air-slacks only after considerable exposure. It burns freely, leaving a gray or buff-colored ash. The lump- and nut-coals are used for domestic and steampurposes (chiefly, however, for locomotive firing), and the slack for making coke. The specific gravity is 1.272. Analyses of Pratt Coal. I. 11. 111. IV. Min. Resources Authority. Phillips. McCalley. of U. s.,1892. Lupton. Fixed carbon,. . 67.90 61.600 64.30 63.82 Volatile material,.. 29.80 31.480 32.08 31.85 Moisture,.,...... 1.508 1.07 1.02 Ash,.... 2.30 5.416 2.08 3.31 Sulphur,. .. 0.83 0.918 0.47 0.70

Jan 1, 1896

By R. F. Mehl, G. V. Smith

THE decomposition of austenite in steels, because of its immense practical importance, has been subjected to extensive study in recent years from the point of view of the mechanism of the process.1-3 Although much information has been acquired, a number of questions, principally of theoretical interest, remain. One is that of the atomic-crystallographic mechanism by which each of the various reaction products forms. The isothermal reaction products of the eutectoid decomposition in plain carbon steels (to which this study is restricted) have conveniently been classified in three general groupings-pearlite, bainite, and martensite. Of these several products, pearlite and martensite have been studied extensively, but bainite has received only scant attention. As a result, the mechanism of the formation of pearlite and that of martensite are now fairly well understood while a great deal of uncertainty exists regarding bainite. PEARLITE Pearlite forms from austenite by the precipitation of alternate platelets of cementite and ferrite, which grow into the austenite matrix .2-5 The rate of reaction may be described in terms of a rate of nucleation and a rate of growth.2.3 Mehl and Smith6 have attempted to determine the lattice relationships existing between the ferrite in pearlite and the parent austenite. Using a pole-figure method of analysis, it was found that a limited number of ferrite orientations resulted from the decomposition of a single grain of austenite; it was not possible, however, to decide between two assumed ideal relationships, both of which appeared to account for the experimentally determined pole figure. It was definitely shown, however, that the relationship obtaining was quite different from that determined for the proeutectoid separation of ferrite.7 No attempt was made to determine the habit plane (matrix plane to which the precipitate lies parallel) of the pearlite lamellae. Belaiew8 earlier had stated that the number of directions assumed by the pearlite lamellae in a single grain of austenite was 12 (no details were given) and concluded wrongly, as Mehl and Smiths have pointed out, that the lamellae delineate the [210] planes of ferrite.* MARTENSITE It is known that martensite is a transitional constituent of body-centered tetrag-

Jan 1, 1942

By G. Derge, L. D. Kirkbride

In recent years the problem of sulfur elimination in iron and steel-making has been of increasing importance. This interest has been due to the increasing amounts of sulfur coming into the system via raw materials. As a result, many investigations have been directed at obtaining information pertaining to the rate and mechanism of sulfur removal in the blast furnace as well as measuring appropriate thermodynamic quantities. Chang and Goldmanl as well as others2'3 showed that the process of sulfur transfer from molten carbon-saturated iron to blast furnace-type slags could be considered as two opposing first-order chemical reactions. Recently, Ramachandran et al.4 have shown that during desulfurization electrical neutrality is preserved in both phases and iron and silicon are transferred into the slag concurrently with the evolution of carbon monoxide gas. They concluded that the reaction s + c-+ (0)=(S) + CO(g) does not express the stoichiometry of the sulfur transfer process. As in all previous investigations, these authors studied the process of a net transfer of sulfur from metal to slag across a slag-metal interface. However, no experimental data have previously been obtained for the process of sulfurization. It was the purpose of this study to investigate the sulfurization process, i.e., net transfer of sulfur from slag to metal. EXPERIMENTAL PROCEDURE Apparatus—The equipment used in this investiga-tion was typical of that used by others.1-3The furnace was a high-frequency induction unit powered by a 35 kw Hg spark gap converter. Fig. 1 shows a schematic diagram of the apparatus. A two-compartment crucible assembly was employed to melt the slag and metal charges; being similar to that used by Ramachandran,4 in size and design. The atmosphere was that produced by reaction of hot graphite with air. Temperature measurements were made by W-Mo thermocouples which were calibrated against a Bureau of Standards Pt - Pt 10 pct Rh couple. Temperature control was always good to * 5°C and in general was much better than this figure. Raw materials used in the experiments were C. P. reagent grade where possible. The silica used in the preparation of the slags was in the form of highly purified silica flour. Silicon and titanium additions

Jan 1, 1961

By Geo. Otis Smith

Twelve years ago, the Director of the United States Geological Survey addressed to the Secretary of the Interior a letter calling attention to the government's need for liquid fuel for naval use and pointing out that the rate of increase in demand was more rapid than the increase in production.' This letter, in a way, inaugurated the policy of public oil-land withdrawals, which was well founded in its primary purpose of protecting the oil industry and highly desirable in its immediate effect of checking the over-development of that day in California. Unfortunately, however, through delays in legislation, this policy may be regarded now as having outlived both its intent and its usefulness. In 1908, the country's production of oil was 178,500,000 bbl., and there was a surplus above consumption of more than 20,000,000 bbl. available to go into storage. In 1918, 10 years later, the oil wells of the United States yielded 356,000,000 bb1.—nearly twice the yield of 1908—but to meet the demands of the increased consumption more than 24,000,000 bbl. had to be drawn from storage. Nor is this all of the brief comparison. In 1918, our excess of imports over exports of crude petroleum was nearly 33,000,000 bbl. whereas in 1908 we exported 3,500,000 bbl., which was net, as we had not begun to import Mexican oil. In this period, the annual fuel-oil consumption of the railroads alone has increased from 16,871,000 to 36,714,000 bbl.; the annual gasoline production from 540,000,000 gal. to 3,500,000,000 gal. This record may be taken not only as justifying the earlier appeal for Federal action, but as warranting deliberate attention to the oil problem of today. Need of Future Supply The position of the United States in regard to oil can best be characterized as precarious. Using more than one-third of a billion barrels a year, we are drawing not only from the underground pools but also from storage, and both of these supplies are limited. In 1918, the contribu-

Jan 1, 1921

By J. R. Eckel

It has long been known that mud properties affect drilling rate and that drilling with water is as much as six to .seven times faster than with mud. However, it is not known why drilling rates with mud are lower. Recent studies show what fluid properties govern microbit drilling rate and also provide a quantitative correlation of these fluid properties and hydraulics with microbit drilling rate. All the microbit tests reported in this paper were made with a low permeability (about 10 md) limestone. They were conducted at constant bit weight and rotary speed with varying fluid properties, flow rate Q and nozzle dinnteter d. The tests showed that (1) drilling rate in a given system with constant circulating rate and nozzle velocity is a function of the kinematic viscosity [viscosity /density, (cp)/ p (density)] of the drilling fluid measured at near bit nozzle shear rates; (2) the combined effect of fluid properties and hydraulics on microbit drilling rate is defined by a Reynolds number function (kQp/dp); (3) for the same kinematic viscosity, drilling rate is independent of solids content; and (4) for the same kinematic viscosity, drilling rate is independent of fluid loss. INTRODUCTION The fact that mudding up reduces rate of penetration is well known, but the reduction varies from well to well. The rate with mud may be 80 percent of the water rate or it may be as low as 15 percent. Since this reduction of up to seven-fold takes place under conditions of constant bit weight, rotary speed and mud circulating rate in a uniform formation, it can only be a result of the change in fluid properties. Previous work1-" both in field tests and in laboratory microbit tests) showed that drilling rate with mud is lower than with water (Figs. 1 and 2). Microbit tests also confirm, at least qualitatively, the field observation that drilling rate slows with increased pressure differential from borehole to formation (Fig. 3). The qualitative effect of drilling rate of bit weight, rotary speed and rate of mud circulation are also the same for the field and microbit rig. For these reasons, the industry generally accepts microbit results as being qualitatively meaningful in terms of field application.

By E. J. Schmitz

This novel safety-lamp, which was first introduced in some of the German coal-mines in 1882, at once attracted general attention in the coal-districts of Europe. Objections which arose during the early stages of its use at the mines have gradually died away with the increase of experience in handling the lamp 011 the part of the miners, and the continual efforts to perfect it on the part of its inventors. Wolf's lamp has rapidly surpassed all its rivals, and has already a greater distribution on the Continent than any one of its older sisters. In the course of two and a half years, the manufacturers have sold 25,000 of the lamps, besides remodelling several thousand rapeseed-oil lamps. This great success, which of itself speaks loudly enough as to the superiority of the Wolf benzine-lamp, is corroborated by both official and private reports, which all agree in pronouncing this lamp the best yet brought forward. It was described in a paper by Mr. Eugene B. Wilson, read at the Chicago meeting of the Institute, in May, 1881,* in which its salient merits were briefly but clearly indicated. Every previous improvement of the original Davy lamp has been directed to one or more of the following main points: 1. Light of greater and more uniform intensity. 2. Freedom from smoke or soot, which clogs the gauze and other parts of the lamp. 3. A greater safety and sensitiveness in the presence of firedamp. 4. An illuminating material which, satisfying the foregoing conditions, should be also cheap. 5. A lock which could not be opened in the mine by the miner. 6. An arrangement for lighting without opening the lamp. 7. An arrangement for changing the size of the flame in the closed lamp, to supersede the picker, the danger from which is explained in Mr. Wilson's paper, already cited. It may safely be said that wolf's lamp was the first to secure all these objects. The adoption of benzine instead of rapeseed-oil (previonsly the best illuminant) has completely satisfied conditions 1, 2, 3, and 4. Benzine gives a much clearer, stronger, and more uni-

Jan 1, 1886

By Oliver B. Knight

The producing formation in the South Field, or "Golden Lane" structure of Mexico, is a buried ridge of reef limestone of Comanchean age overlain unconformably with sediments of Upper Cretaceous, Eocene and Oligocene. The structure extends in a long sweeping arc, with the convex side toward the west, from San Geronimo, Vera Cruz, to San Isidro, south of the Tuxpam River, which it crosses at the town of Alamo. It is 52 miles long and averages 3/4 mile in width. The surface of the producing formation of El Abra limestone consists of a series of minor parallel highs which are separated longitudinally by synclinal troughs and laterally by structural saddles. The presence of these highs has been of utmost importance in the development of the field, especially in recent years when the salt-water level has risen above the synclines and confined the oil to the isolated highs. In many cases, faulty information and interpretation of the subsurface has resulted in drilling costly dry holes and salt-water wells. Development The development of the Golden Lane was started by the Mexican Eagle Oil Co. in 1906. San Diego No. 3, usually known as Dos Bocas, the first producing well on the structure, was completed on July 4, 1908. This well came in unexpectedly for an estimated daily production of 129,000 bbl., and, as the casing was not properly set, the well flowed wild into the Tamiahua Lagoon, causing a loss of several million barrels of oil. In flowing wild the well formed a crater which covers an area of 48 acres, out of which salt water and small quantities of gas still flow. Casiano No. 2, the Huasteca Petroleum Co., which yielded 200 bbl. of oil daily, and which was completed in November, 1909, was the next producing well to be drilled on the structure. In 1910, the same company completed Casiano No. 7, with an initial production of 50,000 bbl. daily, and Casiano No. 1, which produced 200 bbl. daily. In the same year, the Mexican Eagle Oil Co. completed its Potrero del Llano wells 1, 2 and 4, with initial productions of 500, 400 and 100,000 bbl. respectively. From 3910 to the latter part of 1919, development proceeded

Jan 1, 1931