Search Documents

Plans for the program of the Arizona Meeting were presented and were approved with the exception of a few details which purposely had been left in abeyance until the return of President Ricketts. The following Committee on Transportation to the Arizona Meeting was appointed: WALTER DOUGLAS, Chairman, CLEVELAND E. DODGE, Secretary, ARTHUR S. DWIGHT, JOHN C. GREEN WAY, JULIUS KRUTTSCHNITT, JR. The Mining and Metallurgical Society of, the Carnegie Institute of Technology was recognized as an Affiliated Student Society.

Jan 5, 1916

THAT the march of civilization has synchronized with progress in the art of utilizing minerals is a proposition that needs no proof. It is a truism. Historians conveniently divide the time that the earth has been inhabited into the Stone Age, the Bronze (more accurately the Copper) Age, and the Iron Age. As archeologists are not entirely in accord as to dates, and as a few centuries make no difference whatever to this particular story, it may be approximated that the Age of Copper began about 8000 years B.C. and that it gave place to the Age of Iron about 1000 years B.C. The logic of this succession-stone, copper, iron-lies in the fact that copper first displaced stone, then iron displaced copper as the standard material out of which the utensils, implements, and weapons, the utilitarian articles of antiquity, were made. After the advent of iron, the mining and smelting of copper continued. Copper and bronze found use particularly in objects of artistic and ornamental nature; but the superior qualities of iron for many purposes were recognized. Useful manufactures of those days consisted principally of knives, hammers, chisels, spear-heads, arrow-heads, and battle-axes. First these were made of stone, then of copper and bronze, then of iron-particularly as there was plenty of iron ore, and the metallurgy was comparatively easy of accomplishment. Of course, the periods of transition dragged slowly. Definite as were the three Ages dominated by the mineral substance from which they get their names, ten or fifteen centuries probably elapsed from the time the first iron was smelted in a small charcoal furnace until it became the accepted material from which to shape a battle-axe. Contrast this with the pace of modern progress. In a brief span, half a dozen more or less deserving candidates for the distinction of having their name

Jan 1, 1933

By Ivan Simon, R. K. McConnell

Anticipating the availability of tiltmeters suitable for use in boreholes, this article proposes a method of using one or more of these meters to determine in situ stress distribution before and after mining operations. Several ways of using relief techniques to measure in situ stresses in rocks have been developed. These techniques, summarized by Merrill,1 involve measuring deformations which take place when a specimen of rock is wholly or partially isolated from the stress field in the surrounding rock. Measurements of rock deformation caused by stress relief from mining operations can, in principle, also be used to estimate in situ stress distributions. Müller2 has mentioned experiments being carried on in Austria with a "deformation indicator" to determine the tilting of holes drilled before a mine opening is made. Similar work using borehole extensometers has been reported by Potts? and Duvall4 has called attention to the possible use of tiltmeters in making these measurements. Considerable attention is now being paid to the use of tiltmeters in detecting rock deformation associated with fault movements, earthquakes, earth tides, etc. The instruments used for these measurements have usually been of the mercury tube, water tube, or quartz fiber type, but because of their large size, and/or fragile nature, such instruments would not be suitable for use in mining stress measurements. Recent instrumentation developments, however, give promise that rugged, sensitive tiltmeters small enough for use in boreholes may soon be available.' In anticipation of these developments, this article presents a number of calculations of the possibility of using one or more tiltmeters emplaced in a drill hole prior to mining operations to determine the in situ stress distribution both before and after a mining operation. Consider point p (x, z) near a tunnel of radius a

Jan 1, 1969

By M. J. Scoble, W. J. P. Leigh

This paper aims to characterise the forms of slope instability incident in surface coal mines in Britain. These are related to observed controlling factors, with particular reference being given to slope geometry and structure. The work is based on specific data collection programmes considering actual stable and unstable mine slopes. Reference is made to field examples.

Jan 1, 1982

By Thomas E. Leontis

INTRODUCTION THE importance of magnesium alloys in the manufacture of aircraft engines has been realized for many years. A concentrated effort has been exerted in the laboratories of the Dow Chemical Co. to develop magnesium-base alloys with improved properties at elevated temperatures whereby greater advantage can be taken of the inherent lightness of these materials. In an earlier publication,1 attention was called to the superior tensile properties and resistance to creep of cerium-containing magnesium alloys at temperatures up to 700°F. More recently, additional data on magnesium-cerium alloys have been furnished by Murphy and Payne.2 The present paper deals with the mechanical properties of sand-cast magnesium alloys containing zinc, at temperatures up to 500°F. The study includes binary Mg-Zn† alloys containing up to 10 pct zinc and several ternary and some polynary alloys based on the Mg-1Zn,†Mg-3Zn, Mg-4.4Zn, Mg-6Zn, and Mg-10Zn binaries. The compositional variation in the tensile properties, hardness, and creep at room and elevated temperatures, and in the electrical conductivity at room temperature has been determined. The results of these tests show that many zinc-containing magnesium alloys exhibit resistance to creep at elevated temperatures significantly higher than that of present commercial magnesium alloys, but lower than that of alloys of the magnesium-cerium type. In addition, they have high tensile properties at room and elevated temperatures and high conductivity. This combination of mechanical properties and conductivity indicates that these alloys should be given serious consideration for commercial applications involving exposure to temperatures higher than those to which present commercial magnesium alloys can be taken safely. LITERATURE The properties of sand-cast magnesium alloys containing zinc as a principal alloying element have not been investigated very extensively, especially at elevated temperatures. The following remarks, which are confined to sand-cast alloys, will serve as a summary of the most important references on this phase of magnesium metallurgy. The first recorded determination of the tensile strength of binary Mg-Zn alloys as a function of zinc content was reported by Aitchison.3 Similar studies, including the measurement of elongation and hardness, have been performed by Gann and Winston,4 Dumas and Rockaert,5 Haughton and Prytherch,6 and by Spitaler, the last being reported by Beck.7 A slight superiority in the tensile strength of chillcast Mg + 8 Zn alloy over the sand-cast alloy was noted by Maybrey 8 That alloys of magnesium containing 5 to 12 pct zinc

Jan 1, 1948

By R. H. Jacoby, M. J. Rzasa

Experimental equilibrium vaporization ratios were obtained for nitrogen, methane, carbon dioxide, ethane, and hydrogen sulfide in natural gas-condensate systems. Two different overall mixture compositions were investigated over the pressure range 500 to 4,000 psia at 100°, 150°, and 200 °F. Partial phase diagrams of the mixtures were obtained; one of these showed a critical point at 204°F and 3,875 psia. These and earlier data' were compared with the Kellogg correlation' at! 100°F and 1,000 psia. INTRODUCTION The authors' have presented equilibrium vaporization ratios for nitrogen, methane, carbon dioxide, ethane, and hydrogen sulfide in complex mixtures, such as natural gas-crude oil and natural gas-absorber oil. Since mixtures of the natural gas-condensate type also occur widely in petroleum reservoirs and often contain the non-hydrocarbons mentioned, it would be useful to have appropriate K data for calculating equilibrium vaporization conditions. Roland, Smith, and Kave-ler' obtained K's for methane and the light hydrocarbons in gas-condensate mixtures; and Poettmann and Katz3 obtained K's for carbon dioxide in a gas-condensate system. The data presented in this paper extend this coverage to include K's for nitrogen and hydrogen sulfide and phase diagrams for the experimental mixtures. EXPERIMENTAL WORK The equipment and experimental procedure was essentially as described previously, except for analysis of the vapor samples. The vapor sample bombs were filled at the pressure and temperature of the run. Immediately after sampling, a portion of this sample was flushed from the bomb into a 650 cc glass bulb, filling it to near atmospheric pressure. The sample in the glass bulb was then analyzed by the mass spectrometer. Some checks were made on this analytical procedure to find the accuracy of measurement of the C + content of the vapor samples. The modifications tried were complete fractionation of the vapor sample and the use of several liquids (depropanized condensate and retrograde liquid from several vapor samples) as calibrating materials for the mass spectrometer. The results obtained from these various checks differed by about 10 per cent relative and this is believed to be the order of accuracy of the vapor C+ concentrations.

Jan 1, 1953

By John Goheen

CONSIDERABLE work has been done in developing a pyrometer to measure the temperature of molten brasses, bronzes, and aluminum in the crucible. On account of the high melting points and the amount of zinc and sulfurous fumes given off from molten brasses, the conditions are somewhat severe for a thermocouple of standard design; but satisfactory results are obtained with a portable pyrometer, 3 ft. (0.9 m.) of connecting lead wire, and a special 5-ft. nickel-nickel chromium thermocouple, composed of rods ¼ in. (6.35 mm.) in diameter. The lower 12 or 24 in., as desired, may be made detachable so that new tips may be connected at little trouble or expense. The portable instrument need not be of the extreme high-resistance type, as the movable parts of the galvanometer of a lower resistance instrument may be better constructed to withstand the continuous handling such an instrument receives. Platinum-platinum rhodium thermocouples, protected with porcelain and graphite tubes, have been used, but the lag in registering the temperature is too great. It has been found that the range of temperature for various brasses is as follows: Red brasses 2200-2250° F. (1205-1234° C.) Yellow brasses 2250-2400° F. (1234-1318° C.) Bronzes 2300-2550° F. (1260-1400° C.)

Jan 11, 1921

By M. W. Cox, V. F. Hollister

EXPLORATION for metallic mineral deposits is carried on by those special adaptations of methods which the explorer believes will yield most economically or satisfactorily the particular answer sought. In this project the usual methods of geologic observation, recording, and interpretation, when combined with magnetic geophysical methods and geochemical soil sampling, led to disclosures of appreciable zinc mineralization where none was visible in surface exposure. Since 1945 considerable work has been done with geochemical prospecting methods, chiefly in determining the presence and distribution of various elements existing in minor amounts in rocks, soil, vegetation or waters of mineralized areas. Such work, in which the U. S. Geological Survey has taken the lead, finds a ready place in the field repertoire of the exploration geologist as a supplement, not a substitute, for other methods. The Chollet project was carried out in 1951 by the American Smelting & Refining Co. near its Van Stone mine in northern Stevens County, Wash., in the area shown in Fig. 1. The Van Stone mine is located in the Onion Creek drainage of the Selkirk Mountains, midway between the towns of Colville and Northport, Wash., and some twenty airline miles west of the Metaline mining district. Its zinc-lead orebodies, currently yielding about 1000 tpd of ore, occur as bedding replacement deposits in the middle Cambrian Metaline formation near an intrusive granodiorite contact. The target of exploration at the Chollet prospect was a similar geologic environment along the intrusive contact about 5 miles west of the mine. Geographic Setting The Chollet ground covers a north-facing slope at 3000 to 4000-ft elevation. Second-growth jack pine and tamarack with some hemlock and yellow pine make a thick forest cover. A heavy under-forest of alder, willow, and lesser shrubs occupies the draws, see Fig. 2. Grassy slopes appear at higher elevations. The lower slopes are underlain by a thick blanket of glacial till and alluvium so that outcrops are scarce; however, perhaps 50 pct rock exposure prevails at higher elevations. This part of northern Washington annually receives about 25 in. of precipitation, which largely falls as snow in the winter months. Summers are dry with occasional rainy periods. General Geology The Van Stone mine and the Chollet prospect lie along the southern margin of a westerly extending lobe of the Kaniksu batholith, one of the series of granodioritic masses that are intrusive into Cretaceous and older rocks in northern Washington and southern British Columbia. The margin is composed of complexly deformed Paleozoic sediments ranging in age from the lower Cambrian Maitlen phyllite on the east, through middle Cambrian Metaline formation (limestone and dolomite), to Ordovician Ledbetter slate on the west. In general the formations strike N10 to 50E and dip steeply northwestward, although dip reversals and minor folding occur. This general rock distribution is shown on Fig. 3. In this area the Metaline formation, which is the host rock for mineralization, appears to be of about 4000-ft thickness that can be conveniently divided into the same three units defined by Park and Cannon' for the Metaline area. The basal part consists of 1000 ft of interbedded white limestone, argillaceous limestone, and gray silty argillite. The middle part, approximately 1500 ft thick, consists of fine-grained black, gray, and white dolomite. This unit also contains minor interbedded limestone. The upper part is a gray massive limestone about 1500 ft thick that grades upward into slaty limestone and slate capped locally by a thin black jas-peroidal dolomite which is either the uppermost member of the Metaline formation or the basal member of the overlying Ledbetter (Ordovician)

Jan 1, 1956

PRESIDENT SAMUEL A TAYLOR, District 3 PITTSBURGH, PA PAST PRESIDENTS WILLIAM KELLY, District 5 IRON MOUNTAIN, MICH J V W. REYNDERS, District 0 NEW YORK, N Y FIRST VICE-PRESIDENT E DEGOLYER, NEW YORK, N Y TREASURER CHARLES F RAND. . . NEW YORK, N Y

Jan 1, 1923

For the first time in its history the Institute will hold a meeting in the State of Arizona. A few years ago Arizona stood third in the copper-producing districts of the United States. Since that time, with the development of porphyry mines, the output has gone up with great rapidity until it not only is the leading district, but its output at the present time is at the rate of nearly double the Montana output, which now stands second in the list. In connection with this .development, most interesting departures have been made in methods -of mining, concentration and smelting. Principles of mining and metallurgy of the greatest interest will be covered by papers which will' appear in the Bulletin and be presented at Technical Sessions, while ample opportunity will be afforded for those who go to the meeting to see all the points of interest .to them. In addition, members will be well rewarded by the marvelous natural features to be seen on the trip, including 'the petrified forests, the cliff dwellings on the Apache Trail and the Grand Canyon of Arizona. It is planned to start the special train from New York, but members and guests may join the special at other points en route as indicated by the following schedule: ITINERARY . , Thursday, September 14th Lv New York, Grand Central Terminal.. ............... 5.30 p. m. Dinner in dining car a la carte New England Members via B. & A. R. R. . Lv Boston. ............. (Regular train). ............. 2.00 p. m. Lv Worcester. ........... (Regular train). ............. 3.12 p. m. , Lv Springfield. ........... (Regular train). ............. 4.37 p. m. Dinner in Dining Car a la carte Ar Albany.. ......... .New York Central R. R.. ....... 7.45 p. m. Lv Albany .......................................... 9.00p.m. Lv Schenectady.. .................................... 9.32 p. m. Lv Utica ............................................ 11.08~.

Jan 8, 1916

By H. C. Spaulding

Every constructing engineer and designer knows how often it is desirable to provide a speed-adjustment between parts of a machine performing different functions, or between a prime mover and the devices to which it furnishes power, and how bulky and unsatisfactory are most of the methods by which the result is usually accomplished. Of course the step-pulley is the most simple and generally used. It requires, (1) parallelism of shafts; (2) a considerable distance between centers; and (3) a cessation of power during the change from one speed to another. Add to this the necessity for careful design in order to obtain equal belt-tension for all positions; the weight and hulk required for a wide range; and the operative's positive conviction that better results could be obtained at a speed intermediate between those furnished by two successive steps, and we begin to realize the mechanical shortcomings of this old and familiar friend. The hundred and one other devices, patented and otherwise, for accomplishing similar results, present other objections of varying importance, which need not be discussed here. Without pretending to overcome these entirely, and indeed without claiming absolute novelty, a recent invention of Mr. E. F. Gordon, of Dover, N. H., has seemed to the writer to offer such advantages in flexibility and range of application as to merit a more extended study and use than can be given in his own work, to which it is being applied as rapidly as opportunity permits. It is placed before the members of the Institute, not only to bring out an expression of opinion as to its limitations, but also with the hope that it will thus find opportunities for applications hitherto untried and outside the scope of operation of those at present interested in its development. Simply stated, the device consists of a narrow pulley with a deep V-groove, split by a plane passing through the bottom of the groove, one of the two symmetrical parts so formed being fixed to the shafts, and the second being capable of adjustment so as to bring the

Jan 1, 1893

Plans have been completed with only details to be arranged for the first Metals Branch Conference in the Northwest. The two day meeting will be held jointly with the Industrial Minerals Div. on Friday and Saturday, May 9 and 10, 1952, at the Davenport Hotel in Spokane, Wash. For, some time the metals activities in this area have been neglected. Expansion of metal producing and fabricating industries in Washington and neighboring states has brought sufficient interest to insure the success of such a meeting. A committee has been hard at work for several months. Nonferrous extractive metallurgy men will find an extensive program in the April issue of JOURNAL OF METALS. Sessions for iron and steel producers, physical metallurgists, and educators will make the Metals Branch picture complete. Metals Branch members residing in Washington, British Columbia, Oregon, Idaho, Montana, Wyoming, Nevada, and Utah, or who can be in the Northwest at this time should make plans now to attend. A Metals Branch luncheon is planned for Friday and a dinner jointly with the Industrial Minerals Div. is planned for Saturday according to F. R. Morral, metallurgist with the metallurgical research div. of Kaiser Aluminum & Chemical Corp., P. O. Box 1451, Spokane, Wash.

Jan 1, 1952

Papers in Classes A-Metal Mining, B-Milling and Concentration, H-Industrial Minerals, and I-Mining Geology are distributed in MINING TECHNOLOGY, which is issued every other month. Papers in Classes C-Iron and Steel Division, D Nonferrous Metallurgy and E-Institute of Metals Division are distributed in METALS TECHNOLOGY, which is issued twice quarterly. Papers in Class G Petroleum Division are distributed in PETROLEUM TECHNOLOGY, which is issued every other month. TECHNICAL PUBLICATIONS in Classes F-Coal Division, J Mineral Industry Education Division, Mining Administration, and L-Geophysics, are issued as separate pamphlets. Contributions are papers that when printed or mimeographed are available, but only on request.

Jan 1, 1946

By Bruce W. Gonser, Robert J. Nekervis

EACH metal has a unique combination of properties that distinguishes it from other metal;. Su& a combination may account for applications that cannot be met very well by anything else. This is particularly true of tin, one of the earliest metals used by man. Table i shows the consumption of tin in the United States by usage for the years 1949 and 1950, which may be considered to be generally typical of current usage. The major applications-tinplate, solders, bronze, and babbitt-were well established a century ago. Applications for the metal and (probably later) of tin alloys started more than 5000 years ago. Fortunately for the ancients, tin is one of the metals whose oxide is easily reduced by carbon. Nature further simplified the refining problem by providing only one ore of commercial importance, cassiterite (SnO2). Tin is easily reduced from cassiterite. All that is necessary is high heat in the presence of carbon. It is quite possible that back in the dawn of history, tin was discovered when black alluvial sand was thrown on a fire, either to bank it or to put it out. SOURCES OF TIN All the important tin-producing centers are in the southern hemisphere, far away from the' industrial consuming centers. Fig 1 shows their location and 1950 production. Reserves are adequate, and the industry is able to produce considerably more tin than is

Jan 1, 1953

PRESIDENT E DEGOLYER, District 0 NEW YORK, N Y PAST PRESIDENTS J V. W. REYNDERS, District 0 NEW YORK, N Y SAMUEL A TAYLOR, District 3 PITTSBURGH, PA FIRST VICE-PRESIDENT GEORGE OTIS SMITH, District 4 WASHINGTON, D C TREASURER CHARLES F. RAND NEW YORK, N Y SECRETARY H. FOSTER BAIN NEW YORK, N Y

Jan 1, 1923

By C. S. Barrett

IT has been observed that deformation in iron takes place by slip on {110} + {112} + {123} planes1,2 but in silicon ferrite with low deforma-tion temperatures or high silicon contents (exceeding 4 per cent) the authors have found that slip is confined wholly to {110} planes, at least with small amounts of deformation. The purpose of the present inves-tigation was to determine the effect of this alteration of slip mechanism on preferred orientations in cold-rolled and recrystallized strips. Inci-dental observations on the effect of the recrystallization temperature were also made. The numerous determinations of the texture of cold-rolled iron and steel have been in satisfactory agreement as to the principal features of the texture. (with the exception of a few conclusions that apparently have been based on insufficient data). The texture is chiefly one in which [110] directions of the grains lie along tile direction of rolling, with a deviation of a few degrees, and in which the (100) planes lie in the plane of the rolled sheet, with a deviation from this position chiefly about the rolling direc-tion as all axis 3-9. This deviation about the rolling direction as an axis has been measured by different observers and lies between about 45° and 50° or 60° for iron5,6,9 and is usually in the neighborhood of 50° for mild steel6,7,8. The range of this deviation is a function of the percentage of total reduction 8, 10. Post' reported that it decreases with increasing percentage reduction, but apparently he .studied only the surface material, which Gensamer and Mehl7 found to be somewhat differently oriented from the material in the inside of the sheet. McLachlan and Davey10 found that the deviation also decreases with increasing percentage of total reduction for the material in the interior of the sheet and is independent of the percentage of reduction per pass.

Jan 1, 1937

By Frank Peterson

THE manufacture of gasoline by extraction or precipitation from the natural gases in which it is found, the present status of. the industry, its past development and future extensions; offer a subject which is so broad that to handle it in its entirety would require a voluminous paper. The writer will, therefore, attempt to concentrate the essential matter of the subject for a general presentation, giving some of the most interesting details of the factors that are important to the industry. This industry has drawn liberally on the principles of physics and chemistry, and, to a large extent, has had to adapt such information as is most useful-not from data recorded with reference to petroleum, but from data recorded with reference to general treatment of other materials. Because of the complex character of the petroleum series of hydro-carbons and the fact that data, such as solubilities, vapor pressures, etc., of the different petroleum compounds have not been determined, we are still working by rule of thumb in. some essential phases of the industry. Furthermore, the difficulties of determining such data are almost insurmountable. We have not one,, but two butanes to deal with-not one, but several, pentanes, hexanes, heptanes, and, as we ascend in the series the complexity and multiplication of isomers increases at such a rate as to make the task of isolating and studying their physical characteristics almost beyond the hope of possible attainment. The industry is the connecting link knitting the interests of oil producers and refiners into a much closer relationship than ever existed .prior to its inception and development. The relation between the producer and the refiner of petroleum prior to 1910 was. a rather antagonistic one in a commercial sense. It was to the interest of the producer of crude petroleum to sell it for a maximum consideration; the refiner's interest was to obtain the same product for a minimum consideration; therefore, each side of the business transaction retained within his own hands as far as possible the trade secrets of his business. Each side maintained an attitude of cold-blooded business sympathy only for the other. Cas-

Jan 12, 1917

By R. L. Doan

WHEN the Plutonium Project was started in the spring of 1942 there was no technology to produce uranium metal of the required purity. Not only was there no such metal available; no one knew how to make it or fabricate it after it was made. Since this time vast technical effort has been ex-pended in the atomic energy field. A short 15 years later the metallurgy of uranium is probably better known than that of any other metal, with the possible exception of steel. At the beginning of the 1942 drive to obtain pure uranium metal the most available raw material was black uranium oxide (U3O8) of about 92 pct purity from the Great Bear Lake region of Canada. It took only three months for the project chemists to develop a process for bringing the purity of this oxide up to 99+ pct and another three months for Mallinckrodt Chemical Co. of St. Louis to build the purification plant and get it into operation. In early summer of 1942 the purified brown oxide (UO2) started moving to the Metal Hydrides Co. in Beverly, Mass., and to the Westinghouse Research Laboratory in Bloomfield, N. J., both of which had been granted Government contracts to try to make pure uranium metal.

Jan 9, 1957

LIST OF THE MEETINGS OF THE INSTITUTE AND THEIR LOCALITIES FROM ITS ORGANIZATION Transactions Number Place Date Vol Page I Wilkes-Barre, Pa * May, 1871 I 3 II Bethlehem, Pa August, 1871 I 10 III Troy, N Y November, 1871 I 13 IV Philadelphia, Pa February, 1872 I 17 V New York, N Y * May, 1872 I 20 VI Pittsburg, Pa October, 1872 I 25 VII Boston, Mass February, 1873 I 28 VIII Philadelphia, Pa * May, 1873 II 3 IX Easton, Pa October, 1873 II 7 X New York, N Y February, 1874 II 11 XI St Louis, Mo * May, 1874 III 3 XII Hazleton, Pa October, 1874 III 8 XIII New Haven, Conn February, 1875 III 15 XIV Dover, N J * May, 1875 IV 3 XV Cleveland, 0 October, 1875 IV 9 XVI Washington, D C February, 1876 IV 8 XVII Philadelphia, Pat June, 1876, V XVIII Philadelphia, Pa October, 1876 V 9 XIX New York, N Y February, 1877 v 27 XX Wilkes-Barre, Pa * May, 1877 vi 3 XXI Amenia, N Y October, 1877 vi 10

Jan 1, 1917

By J. F. Emig

The Burns Harbor Plant was designed to produce and process large ingots into plate, hot rolled sheet, cold rolled sheet and tin plate. Rimmed ingots, in particular, are poured 96" to 106" high and weigh up to 85,000 lbs. During the latter part of 1970, a quality problem was encountered involving white line "sliver" defects on the surface of cold rolled, low carbon, rimmed steel sheet. Sheets containing these defects are not desirable for exposed automotive items because of the possibility of opening during forming or becoming more apparent after forming. Metallographic work located and identified two basic types of inclusions within the white line defects: (1) complex oxides consisting largely of iron and manganese oxides and (2) scale-type iron oxide. The presence of these oxides strongly suggested that the-white line defects were resulting from an unsound, unclean rim zone.

Jan 1, 1972