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By George M. Enos, Robert J. Anderson

An impoRtant factor affecting the rate and nature of corrosion of metals and alloys is the film, or coating, formed on the surface; and this may accelerate or retard corrosive action once started. The formation of films and coatings is intimately associated with the chemical composition and physical constitution of both the metal and the corroding medium. A film or coating may be either the corrosion product resulting from oxidation; that is, an oxide or salt, or a deposition of suspended matter from the corroding media upon the surface of the metal, or a mixture of both. The coating may adhere tightly or loosely to the surface of the corroded metal. In short, a film or coating is the reaction product of the corroding medium and the metal, which adheres to the surface of the metal and with which may be intermingled material from the attacking media not concerned in the chemical reactions. As the terms film and coating are used by different writers for very different things, distinction is made between the two, by the present writers, on the basis of thickness. Thus, a film is defined as a corrosion product or deposition, on the surface of a corroded metal, that is of such thickness that it cannot be measured by the metallurgical microscope. A coating, on the other hand, is of such thickness that it can be measured. If the resolving power of the 2-mm. (equivalent focal length) apochro-matic oil immersion objective (N.A. 1.4) is taken as the limit of the microscope, the limiting resolution is two lines that are 0.0002 to 0.0004 mm. apart. It is thus possible to measure coatings that are greater than 0.0002 to 0.0004 mm. thick. This thickness is equivalent to 50,000-

Jan 1, 1925

By Michael B. Jones, Wayne R. Bruce, Cyrus W. Field

For more than a decade the Pacific Northwest has been a frontier of successful porphyry copper-molybdenum exploration. This vast region (about 2100 miles long, 350-500 miles wide) occupies a geologically complex mobile tectonic belt. It parallels the Western Cordillera from northern California-Nevada to southern Alaska-Yukon Territory, and west from the northern Rocky Mountain-Tintina Trenches to the Pacific margin. Right lateral displacement has occurred along major transcurrent faults that are sub parallel to the region and the transform Fairweather-Queen Charlotte fault zone separates the North American continental plate from the Pacific oceanic plate. Porphyry-type deposits are widespread, but producing mines are restricted to south and central British Columbia. Size and grade are variable (25 to +300 mt; 0.18 to 0.65% Cu with 0.014 to 0.049% MoS2; 0.14 to 0.28% MoS,) and secondary enrichment is normally unimportant. Metallization is genetically and spatially related to late quartz-feldspar porphyries that are within, marginal, or satellitic to composite batholithic intrusions. Radiometric ages of the plutons range from Miocene to Triassic-Jurassic (18 to 217 m.y. [million year] ). Country rocks are typically eugeosynclinal metasedimentary and metavolcanic assemblages of Permian to Jurassic age. Several of the older (pre-Late Cretaceous) deposits formed in submarine island arc environments and they may be genetically related to occurrences of volcanogenic sulfides in the greenstone country rocks. Deposition of bornite-chalcopyrite-molybdenite ores is controlled by contacts, breccias, and fault-fracture zones. Associated hydrothermal gangue minerals include biotite, orthoclase, sericite, kaolinite, quartz, anhydrite, and tourmaline. Isotopic data suggest a deep source for ore, gangue, and plutonic host rocks. Significant exploration features include porphyries, dike swarms, breccias, potassic alteration, barren quartz cores, gossans, and fringing halos of pyrite and propylitic alteration.

Jan 1, 1975

By Comfort Adams

WHEN this country went into the war, but two concerns, The Bethlehem Steel Co. and The Midvale Steel and Ordnance Co., knew how to make steel fit for great cannons and at these concerns there were relatively few men who knew the whole art. Fortunately, certain of these men put their knowledge at the service of the Government, and proceeded to instruct the metallurgists at the arsenals and at various steel works. The then chairman of the Engineering Division of the National Research Council, Doctor Howe, suggested that this work might be facilitated, and the number of effective gun-steel makers thereby increased, if a detailed description of the best practice could be written, giving the reasons for the various steps, and issued with the endorsement of a committee composed of those who were evidently the most competent authorities. It was thought that something would be gained by clarification of the subject, and something by the eminent authority' of the members of the committee. To that end, the Engineering Division appointed-a committee, consisting of the gentlemen whose names follow, to mention only those who retained their connection with it. At, this time there were serious difficulties in the manufacture for the Government, of aircraft and high-speed engine crankshafts, of certain ordnance forgings, and of shells for both the Army and Navy. This Committee was asked to study and report upon these, with a view to betterment of practice. There were indications that the source of some of the difficulties went back to the melting of the steel and the production of the ingot. Hence, the committee first studied steel melting and ingot production, in order to guide the wartime manufacturers to an even larger percentage of useful production from the steel initially melted.

Jan 1, 1922

By Charles Wraith

THE property of the Roan Antelope Copper Mines, Ltd., is situated at Luanshya, north-central part of Northern Rhodesia, and is connected with the main line of the Rhodesia Railways, Ltd., by a 24-mile branch line from N'dola. Most of the material and supplies that are not available in Africa are shipped into the country via Beira, on the East Coast of Africa, a distance of 1473 miles from Luanshya and the nearest ocean port. The output of copper is shipped by rail to Beira and thence by boat to the market. Passenger travel is mostly via Cape Town, a distance of 2162 miles from Luanshya. Excellent passenger trains operate on regular schedules between Cape Town and Northern Rhodesia. Luanshya is 13° south of the equator at an elevation of 4000 ft. above sea level, and has a mild healthful climate. During the rainy season, from October to March, the rainfall averages 53 in. The area is pro-fusely covered with vegetation. An ample supply of water for industrial and domestic purposes is available throughout the year. The more important supplies for smelting purposes, such as wood, coal, limestone, silica, quartzite, and clay for "dolly" mud, are con-veniently available. Excellent grades of coal, coke and firebrick are obtained from the Wankie Colliery Co., Ltd., Southern Rhodesia. The Wankie colliery has just completed the erection of equipment for the manufacture of silica brick. An ample supply of quartzite of good grade is available for this purpose. Silica brick is also obtained from the Belgian Congo and from India. Limestone is quarried from a large deposit a few miles from Bwana Mkubwa, which is 30 miles by rail from the smelter. An abundant supply of clay for "dolly" mud and for lining launders is available within a short distance of the smelter.

Jan 1, 1933

By E. R. Parker, R. H. Thielemann

The conventional short-time tensile test provides a reliable means of predicting the sustained load-carrying capacity of steels only when the temperature is such that continuous plastic flow does not occur. At elevated temperatures, stresses considerably less than the short-time rupture value may produce continuous flow, with fracture occurring only after long periods of time. The amount of flow or creep accompanying failure varies for different steels, and depends, to a large extent, on the temperature and the duration of the test. Service records of cracking stills, steam superheaters and high-temperature boilers have shown that brittle fractures sometimes occur with little or no warning. In installations of this type, localized stresses are often encountered, and steels must be capable of withstanding a certain amount of deformation without fracture. The sustained-load rupture test determines the expected life and corresponding ductility of steels at various stresses and temperatures. It also yields additional information regarding the effect of micro-structure and metallurgical stability on the high-temperature properties. Present Status of Sustained-load Rupture Test The sustained-load rupture test conducted at elevated temperatures is not entirely new. Dr. Zay Jeffriesl presented in 1919 the results of a large number of rupture tests made on copper, iron and tungsten. These tests were made with various strain rates and at temperatures ranging from the boiling point of liquid air to 1000° C. At that time he observed the interesting phenomenon characteristic of metals, that a temperature exists below which a metal is ductile and breaks with a transcrystalline fracture (through the grain) and above which the metal is brittle and breaks with an intergranular fracture (through the grain boundaries). He observed that this temperature varied with the testing speed, and that a minimum temperature, slightly above the recrystallization temperature, existed at which the cohesion of the grains themselves was

Jan 1, 1939

By R. H. Thielemann, E. R. Parker

The conventional short-time tensile test provides a reliable means of predicting the sustained load-carrying capacity of steels only when the temperature is such that continuous plastic flow does not occur. At elevated temperatures, stresses considerably less than the short-time rupture value may produce continuous flow, with fracture occurring only after long periods of time. The amount of flow or creep accompanying failure varies for different steels, and depends, to a large extent, on the temperature and the duration of the test. Service records of cracking stills, steam superheaters and high-temperature boilers have shown that brittle fractures sometimes occur with little or no warning. In installations of this type, localized stresses are often encountered, and steels must be capable of withstanding a certain amount of deformation without fracture. The sustained-load rupture test determines the expected life and corresponding ductility of steels at various stresses and temperatures. It also yields additional information regarding the effect of micro-structure and metallurgical stability on the high-temperature properties. Present Status of Sustained-load Rupture Test The sustained-load rupture test conducted at elevated temperatures is not entirely new. Dr. Zay Jeffriesl presented in 1919 the results of a large number of rupture tests made on copper, iron and tungsten. These tests were made with various strain rates and at temperatures ranging from the boiling point of liquid air to 1000° C. At that time he observed the interesting phenomenon characteristic of metals, that a temperature exists below which a metal is ductile and breaks with a transcrystalline fracture (through the grain) and above which the metal is brittle and breaks with an intergranular fracture (through the grain boundaries). He observed that this temperature varied with the testing speed, and that a minimum temperature, slightly above the recrystallization temperature, existed at which the cohesion of the grains themselves was

Jan 1, 1939

By ARCHIBALD DOUGLAS

BY this time almost everyone knows, in a general way, the corporate income distribution policies of the 1936 Revenue Act, and many of the practical problems arising there under. This article is not intended to be a technical discussion of that act by title, subtitle, section, or supplement, nor an analysis of inter- dependent sections of the various acts over many years woven on the fiscal loom f our Congressional machine. Such a discussion would require the spinning of a web of words too long for patience. Yet ,a general statement of the underlying plan of the 1936 Act, so far as it affects dividend policies, is perhaps useful.

Jan 1, 1937

By Frederick M. Becket

SHORTLY after the Armistice there appeared a few references to numerous attempts that had been made to produce steel without the aid of manganese, or at least with manganese in abnormally low percentage. Some years later, during two consecutive days of train travel, I had excellent opportunity to read Sir Robert Hadfield's book, entitled "Metallurgy-Its Influence on Modern Progress," and also his paper, "The Metal Manganese and Its Properties : Also the Production of Ferro-Manganese and Its History," presented at the spring meeting of the Iron and Steel Institute, 1927. Both the book and the paper are most interesting historically to makers of alloy steels and

Jan 1, 1931

By C. E. MacQuigg

BY and large the education of the engineer has been conservative and the reasons for this are obvious. Quite properly it has been a tradition of engineering education that facts and not fancies must be adhered to. Without a doubt, those men who formed the mold of our engineering philosophy as much as it is possible for such molds to be established-rightly held the highest standards of intellectual honesty. Fortunately, it was unthinkable to them to temporize with untried theories and naturally the men whom they trained as engineering educators carry this philosophy in turn to their students, thus handing down the tradition of stability.

Jan 1, 1943

By Thomas V. Falkie, Robert Stefanko

Recently The Wall Street Journal featured a series of articles titled "The Dirty Work-Brutal, Mindless Labor Remains a Daily Reality for Millions in The US.-Mining Coal, Shoveling Slag, Gutting Hogs Pays Bills But Can Drain Spirit, Hope." The article was devoted to describing how tough and dangerous is mining (and some other jobs) and how rough life is for miners and their families. Similarly during the past few years some psychiatrists and sociologists have devoted increased attention to the attitudes and life styles of miners. Unfortunately most of their approaches have been neither scientific nor objective, and very little good clinical research has been done on the subject.

Jan 1, 1971

By AIME AIME

NOT a few physical metallurgists started their profession- al careers as chemists or physicists, only to surrender later to the attractions of metallurgy. The present Institute of Metals Chairman varied this more usual sequence in hat his first love was electrical engineering, when as a recent graduate he served on the staff of the General Electric Co., of Schenectady. Soon turning to metallurgy as a more interesting field, he was metallurgist and then chief engineer of the Wads- worth Watch Case Co. from 1920 to 1927. Since 1927 he has been with the International Nickel Co. at the Bayonne, N. J., research laboratories where he is staff adviser.

Jan 1, 1940

New equipment for seabed sampling, presently at the prototype stage, operates on the principle of diamond core drilling with wire line core barrels and is designed to drill cores from the seabed at depths down to 200 m with a continuous recovery of cores from an attendant vessel. The machine operates on the seabed by remote control from a console on the vessel. Neither installation nor operation requires the use of divers. Principal Applications Principal areas of application for the drill which is dubbed Maricor include investigation drilling in the continental shelf, mapping geological conditions before large drilling platforms are installed and exploring proposed undersea tunnel routes.

Jan 11, 1973

By James A. Soles

Concrete is a complex, multicomponent mass whose stability is dependent on three principal variables: quality of the mix, its composition, and environment of the site. The aggregate is only one component, but its constituent minerals may react in unfavorable regimes and, given sufficient time, destroy the concrete. Therefore, besides ensuring that a concrete will meet the strength requirements of a structure, the concrete engineer must be confident that the mortar and aggregates will resist destructive processes. This paper reviews the principal causes and effects of aggregate instability, notes reactions of certain phases, and suggests precautionary measures that can be taken to extend the useful life of concrete structures.

Jan 1, 1984

The sixty-fifth Congress created a commission on classification and standardization of wages of Government employees consisting of three members of the Senate and three ex-members of the House of Representatives: The Chairman of the National Service Committee has been notified orally by the Vice-chairman that when said Commission reaches the consideration of engineers' salaries in the Government service, request will be made for assistance of Engineering Council. As it is probable that this request will be received prior to the June meeting of Council, it is recommended that action be authorized concerning the appointment of a suitable committee of Council to undertake this work.

Jan 6, 1919

By W. O. Philbrook

ALTHOUGH the actual output of about 89 million tons fell a little short of the hopes and more optimistic predictions of the beginning of 1943, the American iron and steel industry last year produced the record tonnage of its history. It was sufficient to catch up somewhat on the crucial needs for prosecution of the war though an excess of demand over available supply of steel still persists in most categories. It will be necessary during the coming year for the operators to continue to devote all of their efforts and ingenuity to obtaining the utmost tonnage both from existing units and from new facilities still to be brought into production.

Jan 1, 1944

The following members were appointed on the Committee Advisory to the U. S. Bureau of Standards: Arthur S. Dwight (Lead). John Fairfield Thompson (Nickel). The reports of the Committee in charge of the Arizona Meeting and the Committee on Transportation to the Arizona Meeting were accepted with the thanks of the Board. The By-Laws of the Nevada Section of the Institute were approved. The subscription price of the Bulletin to non-members of the Institute was increased to $12, per year beginning with January, 1917. This increase does not affect the reduced price of $5 on extra copies of the Bulletin which are sold to members, libraries and sister societies.

Jan 7, 1916

Annual Meeting, February 17 to 19, 1914.-The following Committees have been appointed to have charge of the arrangements for the Annual Meeting in New York City: . General Committee: Louis D. Huntoon, Chairman; Arthur S. Dwight, Vice-Chairman; W. deL. Benedict, George F. Kunz, Thomas T. Read, E. Maltby Shipp. Reception Committee for Each Day: Chairmen to be announced later. Banquet Committee : Theodore Dwight, Chairman. Luncheon Committee: E. Maltby Shipp, Chairman. Ladies' Committee: Mrs. Arthur S. Dwight. Badge Committee : George F. Kunz, Chairman; E. Maltby Shipp, Vice-Chairman. Program Committee: Thomas T. Read, Chairman. Bureau of Registration and Information: Burr A. Robinson, Chairman.

Jan 1, 1914

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members who registered at Institute headquarters during June: Ralph H. Sweetser, Columbus, Ohio. O. M. Bilharz, Rivermines, Mo. Etienne A. Ritter, Colorado Springs. Colo. Joseph A. Holmes, Washington, D. C. Dwight E. Woodbridge, Duluth, Minn. Francis Church Lincoln, Urbana, III. Arthur Chippendale, Mexico City, Mex. William E. Saunders, Philadelphia, Pa. E. T. Miller, Louisville, Ky. E. P. Ross, Johnson City, Tenn. Jesse Scobey, Denver, Colo. H. M. Boylston, Cambridge, Mass. Charles Rhodes, Auckland, N. Z. Edward Keller, Perth Amboy, N. J. John W. Finch, Denver, Colo. F. G. Cottrell, San Francisco, Cal.

Jan 7, 1913

Magazine, Advertising $ 32,823 60 Sale of Magazines 3,93329 Total Magazine $ 36,756 89 Dues, 'Arrears 5,866 97 Dues Current 100,223 80 Dues of New Members 6,143 29 Dues in advance 1,586 32 Initiation fees 6,820 00 Sale of Transactions 5,464 99 Sale of Binding 5,618 90 Sale of Pyrometry Volume 336 30 Sale of Indexes and Emmons 106 10 Sale of Pamphlets 575 32 Miscellaneous Receipts 105 60 Interest on Bank Balances 1,217 67 Interest on Life Membership Investment 512 18 Interest on James Douglas Library Fund 5,678 67 Total Receipts $177,013 00

Jan 1, 1923

EVERY forward-looking mining company realizes the need for employing graduate mining engineers so that there will be a supply of qualified men from which to draw for company officers, executives, and mine managers. The mining industry is competing today with numerous other fields of engineering for its supply of technical men, many of which are more attractive than mining because of better pay, living conditions, and well- regulated company training programs. The Ontario Mining Association and the mining companies of Ontario are conducting a postgraduate training plan which if adopted in the United States, might well encourage top quality men to study mining.

Jan 3, 1950