Search Documents

By Paul M. Tyler

NOW that the dust of World War II has settled and we and our allies are faced with extravagant losses of men, money, and materials, virtually the only hope that the United States and Britain have in the way of reparations lies in the capture of industrial, technical, and scientific secrets. Even during the war American and British scientists and technicians gained access to German factories, questioned German personnel, studied German documents, and endeavored generally to keep pace with new discoveries in science, industrial technology, and process development. Under various agencies this work continued for two years after the war. Altogether at least 600 American scientists and industrialists have gone to Germany and brought back reports and several times as many British, Canadian, and. Australian investigators have been similarly engaged under co-operative arrangements designed to assure the maximum of coverage with a minimum duplication of effort. As a result of these investigations and document studies, about 500 or 600 reports have been prepared on metallurgical and allied subjects. Those by American authors or joint teams have been listed in the annotated Bibliography of Scientific and Industrial Reports, issued by the Office of Technical Services in the U. S. Department of Commerce. Many of the British reports are also available in this country through the same office or through a British representative in New York. Since it was my duty to read most of these reports for

Jan 1, 1948

By Arthur Wade

During the year 1938, there was some drilling in Queensland, New South Wales and Victoria, as follows: Queens1and.—At Hutton Creek, lat. (approx.) 25° 45' S.; long (approx.) 149°, drilling was done by Drillers limited (subsidiary Oil Search) to a depth of 4688 ft., to the Lower Permian(?). There were small gas showings. The hole mas abandoned. At Mt. Bassett, lat (approx.) 26" 20' S.; long. (approx.) 149", Roma Blocks Oil Co. No Liability drilled to a depth of 4033 ft. The hole bottomed in granite. There were small showings of' oil and gas above bedrock in what may be Permian but is not yet determined. The company intends to run a formation tester. New South Wales.—At Kulnura, lat. (approx.) 33" S., long (approx.) 151°, the Kamilaroi Oil Company Ltd. (subsidiary of Oil Search Ltd.) drilled to a depth of 6293 ft. The Permian, probably Upper Marine Series, was reached. Drilling is to continue. Victoria.—At Romawi, lat. (approx) 37" 50' S., long. (approx.) 147" 45', a dry hole 3246 ft. deep bottomed in the Jurassic and was abandoned. It was drilled by the Governments of the Commonwealth and the State of Victoria. At Lakes Entrance, 1st. (approx.) 37" 50' S.; long. (approx) 748", a small showing of' oil (a few pints a day) was obtained from a well drilled 1275 It., to the Upper Oligocene-Glaucnnitc series, by the Austral Oil Drilling Syndicate, No Liability. Future Drilling Preparations is are being made by companies fur further test drilling in 1939, and the Governments of the Common wealth and the State of Victoria are continuing test holes for information only in the Gippsland district of Victoria. In Papua and New Guinea, no test drilling was done in 1938, but several companies are carrying on geological investigation and it is expected that, some test holes will be drilled during 1939.

Jan 1, 1939

By Arthur Wade

During the year 1938, there was some drilling in Queensland, New South Wales and Victoria, as follows: Queens1and.—At Hutton Creek, lat. (approx.) 25° 45' S.; long (approx.) 149°, drilling was done by Drillers limited (subsidiary Oil Search) to a depth of 4688 ft., to the Lower Permian(?). There were small gas showings. The hole mas abandoned. At Mt. Bassett, lat (approx.) 26" 20' S.; long. (approx.) 149", Roma Blocks Oil Co. No Liability drilled to a depth of 4033 ft. The hole bottomed in granite. There were small showings of' oil and gas above bedrock in what may be Permian but is not yet determined. The company intends to run a formation tester. New South Wales.—At Kulnura, lat. (approx.) 33" S., long (approx.) 151°, the Kamilaroi Oil Company Ltd. (subsidiary of Oil Search Ltd.) drilled to a depth of 6293 ft. The Permian, probably Upper Marine Series, was reached. Drilling is to continue. Victoria.—At Romawi, lat. (approx) 37" 50' S., long. (approx.) 147" 45', a dry hole 3246 ft. deep bottomed in the Jurassic and was abandoned. It was drilled by the Governments of the Commonwealth and the State of Victoria. At Lakes Entrance, 1st. (approx.) 37" 50' S.; long. (approx) 748", a small showing of' oil (a few pints a day) was obtained from a well drilled 1275 It., to the Upper Oligocene-Glaucnnitc series, by the Austral Oil Drilling Syndicate, No Liability. Future Drilling Preparations is are being made by companies fur further test drilling in 1939, and the Governments of the Common wealth and the State of Victoria are continuing test holes for information only in the Gippsland district of Victoria. In Papua and New Guinea, no test drilling was done in 1938, but several companies are carrying on geological investigation and it is expected that, some test holes will be drilled during 1939.

Jan 1, 1939

Aalde, Kaare, (S'40) Box 827, Socorro, N. M. Aase, Glenn D., (S'40) Engr. Experiment Sta., Univ. of Utah, Salt Lake City, Utah. Abadesco, Enrique A., (S'39) Student. College of Engrg., Univ- of the Philippines, Manila, P. 1. Abbott, John L., (S'40) Met. Engr., Engr. Trainee. Wright Aeronantical Corp., Paterson, N. .J. Abbott, Robert H., (S'42). Agricultural & Mech. College of Texas, College Sta., Tex. Abreu, Ovidio M., (S'38) Dept. of Geol., Compauia Cousulidada de Petroleo, Caracas, Venezuela. Acomb, Allen, (S'41) 3921 Chestnut St., New Or¬ leans, La. Adam, Howard W., (S'41) Montana School of Mines, Butte, Mont. Adams, Charles E., (S'42) Uuiv. of California, Los Angeles, Calif. Adams, Charles W., (S'39) Student, Michigan Col¬ lege of Min. & Tech., Houghton, Mich. Adams, H. Travis, (S'39) 310 South 5th St., Bur¬ bank, Calif. Adams, John W., (S'42) Univ. of Texas, Austin, Tex. Adams, Rob L., (S'40) Lt., B. 0. C. No. 12, Fort Sill, Okla. Adamson, Charles R., (S'41) Uuiv. of Utah, Salt Lake City, Utah.

Jan 1, 1942

By C. A. Meissner

THE following is a further discussion of the paper of James Gayley, " The Application of Dry-Air Blast to the Manufacture of Iron " (Trans., xxxv., 746), with special reference to his sup-plementary paper (Bi-Monthly Bulletin, No. 4, July, 1905, pp. 797 to 819), and. to the paper of J. E. Johnson, Jr., "Notes on the Physical Action of the Blast Furnace " (Bi-Monthly Bulletin, No. 5, September, 1905, pp. 1111 to 1146). Mr. Gayley's paper has been discussed also by E. Windsor Richards, R. W. Raymond, E. H. Saniter, W. J. Foster, H. M. Howe, V. Pendred, B. H. Thwaite, James Gayley and Alexander Pourcel (Trans., xxxv., pp. 1022 to 1042), Joseph W. Richards (Bi-Monthly Bulletin, No. 4, July, 1905, pp. 703 to 718); T. W. Robinson (Bi-Monthly Bulletin, No. 4, July, 1905, pp. 788 to 796) ; C. B. Dudley, R. W. Raymond, J. E. Johnson, Jr., W. F. Mattes, James Gayley, David Baker, John Birkinbine and F. E. Bachman (Bi-Monthly Bulletin, No. 5, September, 1905, pp. 1147 to 1152);.E. de Mille Campbell (Bi-Monthly Bulletin., No. 1, January, 1906, pp. 25 to 50) ; John Birkinbine (Bi-Monthly Bulletin, No. 1, January, 1906, pp. 137, 138). At the Washington meeting of the Institute, May, 1905, a very instructive and interesting paper was presented by Mr. J. E. Johnson, Jr., entitled " Notes on the Physical Action of the Blast Furnace,"' in which reference is made to Mr. Gayley's dry-blast process. A few of Mr. Johnson's conclusions, as summarized in the last pages of his paper, do not appear to me to be in complete accordance with the results obtained at the Isabella furnaces; and I therefore present the following notes which may throw further light on this subject: Mr. Gayley has called attention to the fact that the moisture in the air is an extremely variable and uncertain factor; and

May 1, 1906

By Hsun Hu, R. S. Cline

The effect of rate of deformation on texture formatiotz has been studied with cube-oriented single crystals of 3 pct Si-Fe, compressed 80 pct at two widely different rates. Compression at a low rate (crosshead speed, 0.1 ipm) produces large orienta-tional changes and coarse deformation bands, whereas little change in orientation is observed, particularly at the surface of the crystal, when compressed at a high rate (impact velocity, -500 ips). Thin plates of mechanical twins are produced at the high rate, but their contribution to the deformation texture is practically negligible. The crystal deformed at a high rate has a lower hardness and a more uniform dislocation structure and is morc resistant to recrystallization. There is also a dilference in the recrystallization texture between the slowly and rapidly compressed crystals. These results indicate that plastic flow is less "turbulent" at high strain rates than at low strain ratcs. THE behavior of metals under high-speed deformation has been the subject of wide study in the past decade. Most of these works were concerned with mechanical properties during testing at high rates of loading, the resulting structures, and the theoretical aspects of the observed phenomena. The present status of knowledge and research activities in this field has been documented in recent publications.17' There is, however, very little information available in the literature concerning the effect of high-speed deformation on the texture formation in metals. The possibility of an effect of rate of deformation on texture is suggested by the microstructural differences observed between normally and very rapidly deformed samples. Aside from the strong tendency for twinning (and phase transformation in certain metals) in high-speed deformation, the slip-line patterns and the dislocation configurations show marked differences as a result of large differences in the strain rates. For instance, in mild steel in static and dynamic compression, Campbell and co-worker3,4 observed that coarse slip occurred on several systems in specimens deformed at normal strain rates, whereas specimens deformed rapidly showed only fine slip on fewer systems, the slip-line pattern being very similar to that in specimens deformed at low temperatures and at normal strain rates. The absence of multiple slip was also noticed by Dieter5 in shock-loaded nickel. The dislocation configuration in an iron shock loaded at 70 kbar pressure was shown by Leslie et al.6 to be similar to that produced by light rolling at low temperature—the dislocation lines were mostly straight and uniformly distributed. These observations suggest that the mode of deformation at high strain rates is notably different from that at low strain rates. Consequently, the nature and the extent of lattice reori-entation during deformation should also be different. This investigation was undertaken to test this idea. MATERIAL AND METHOD The remaining part of a single-crystal ingot of a 3 pct Si-Fe alloy,* prepared for an earlier investi- gation,1 was used in the present studies. Specimens 9/16 in. square and 0.365 in. thick were cut from this ingot with (001) planes parallel to the square surfaces, and the [loo] and 1010] directions parallel to the edges of the specimen, within ±1 deg. These machined crystals were etched to remove distorted metal, and annealed at 1300°C for 24 hr in a purified helium atmosphere. The annealed crystals had a hardness of 161 Dph. The crystal orientation was rechecked with X-ray back-reflection techniques. In high-strain rate experiments the crystal was compressed in a Dynapak machine to approximately 80 pct reduction in thickness (from 0.360 to 0.070 in. with an impact velocity of -500 ips). Thus, the duration of loading was approximately 6x 10-4 sec, and the average strain rate was about 103 sec-1. As a result of this rapid, severe deformation, the specimen became a roughly circular thin disc. The original shape of the crystal, however, could still be recognized by a diffusely outlined square area in the center of the disc. For compression at a low speed, the crystal was deformed in a universal testing machine at a rate of crosshead movement of 0.1 ipm. Compared with

Jan 1, 1965

By Persifor Frazer

CONTENTS. PAGE 1. Committee House of Commons Report (1843).......521 2. Clark (1880).............521 3. Schröder and Schertel (1884).... . 521 4. Committee House of Lords Report (1887).......523 5. Vita (1890).............524 6. Irvine (1890-1)............524 i. Cramer (1891)............525 8. Bailey. Cohen. Tatham and Hartog (1891))......525 9. Morrison (1891)............525 10. Brunner (1891)............525 11. Bell (1892).............585 12. Oades (1892).............526 12a. Purcell (1892)............526 13. Sennett (1892)............526 14. Bulier (1892).............526 1.7. Wiesner (1892))...........526 16. Thomson (1892)............530 17. Fletcher (1892)............530 18. Committee Engineers' Club Report (1892).......530 19. Cohen and Hefford (1892)..........531 20. Discussion Soc. Chem. Ind. (1893). ..532 21. Reuss (1893).............532 22. Thomson (1894—5) ...........535 23. Clowes and Feilmann (1895). ...536 24. Callan (1895)...........536 2.5. Wright (1895)............536 25A. Mabery (1895)............536 26. Re- (1896). ..........536 27. Herman (1896)............ 537 28. Cohen and Russell (1896).......... 537 29. Dennstedt and A hrens (1896). ..537 30. Cohen (1897). ...........537 31. Drehschmidt (1897)........... 538 32. Pfeiffer (1898). .........538 33. Fritzche (1898)............ 540 34. Ost and Wehmer (1899)........... 540 35. Donkin (1899). .........541 36. Beilby (1899)............. 643 37. Berthelot (1900)............ 544

Jan 1, 1908

By Philip Bucky

THE term "longwall mining" is best known to coal men, although modifications of the method are continually being used in other fields. Longwall mining is of interest today because it makes for greater mecha-nization and better supervision at the working face, and therefore lower production costs and increased safety. It is an approach to the factory system of production, the high efficiency of which as compared to that in mines is well known. There is available an accumulation of experience regarding this work but coordination of experience is lacking and this series of experiments was undertaken to help serve this purpose. Model experiments were used for reasons of safety, cost and time, and because it has been previously shown1,2,3 that a scalar model built of the same material as the prototype will behave in a manner similar to that of the prototype, with time effects the same, if the effective weight of the model is increased in the same proportion as its linear dimensions are decreased. This is accomplished by substituting a centrifugal for the gravitational field; i.e., placing the model in a centrifuge and controlling the strength of the centrifugal field by varying the rate of rotation. Many factors affect the behavior of the geologic material overlying a bed, therefore results and conclusions contained in this paper apply only to the conditions presented herein.

Jan 1, 1938

By W. B. Tucker

UNUSUAL interest has recently centered in the Mojave mining district of California, owing to new discoveries of gold ore at the Silver Queen mine, and subsequently at other neighboring proper- ties. These finds have proved that opportunities exist for the prospector even in old mining districts, where careful search may still be rewarded. The Mojave district is characterized by a group of small hills centering around Soledad Butte, four to six miles southwest of Mojave, in Kern County. This butte is 1250 ft. higher than the surrounding desert and 4000 ft. above sea level. Four miles west of Soledad Mountain are the so-called Middle Buttes, a group of flat-topped hills. Gold was first discovered in the district in 1894, and the following productive mines developed: Queen

Jan 1, 1936

By J. L. Lamont, W. Crafts

Studies of the effect of composition of steel on hardenability by Grossmann,' and as-quenched hardness by Field2 and by the authors, have made it possible to predict the results of quenching when the composition and cooling rate are known In order to extend the application of the hardenability calculation to the quenched and tempered condition in which steel is finally used, a survey has been made of the hardness changes caused by tempering. From this study a method has been developed for the prediction of hardness and tensile strength of steel in the tempered condition. The method of calculation was developed from Rockwell C hardness tests on quenched and tempered Jominy specimens and is expressed in Rockwell C hardness units. It is of an additive type in which the degree of softening from as-quenched hardness is estimated. Tem-pred properties may be calculated within about plus or minus 5 Rockwell C hardness or plus or minus 15,000 lb. per sq, in. tensile strength. This degree of accuracy is less than that necessary for the control of heat-treatment, but is adequate for the comparative evaluation and selection of alloy steels. The formula indicates that tempered hardness is primarily dependent on as-quenched hardness and, as in the hardening reaction, the progress of tempering is controlled mainly by the carbon content. Alloys tend to retard softening by a secondary hardening mechanism in which the alloy appears to migrate from ferrite to the carbide phase. The factors for the effects of alloys in tempering vary so much from the effects of alloys in hardening that different steels of equivalent hardenability may, after like heat-treatment, differ considerably in tensile strength. Procedure In developing the method for calculating tempered Rockwell C hardness, simple and complex steels were tested over a range from 0.08 to 0'65 per cent carbon and up to 2.68 per cent manganese, 2.18 silicon, 3.50 chromium, 4.94 nickel, and 1.06 molybdenum. The steels were made as small induction-furnace heats at the Union Carbide and Carbon Research Laboratories, Inc' The accuracy of the method was finally checked on a variety of carbon, low-alloy and high-alloy types of heat-treating steels produced under commercial conditions. The method was based on a study of tempered Jominy bars, and its validity was tested by correlation with the center hardness and tensile strength of oil-quenched and tempered bars from 1/2 to 4 in. in diameter. The method of calculation was derived from the differences in Rockwell C hardness between as-quenched and quenched and tempered Jominy specimens. Prenormalized Jominy hardenability speci-menS quenched from a normal temperature for austenitizatios were used to obtain a range of as-quenched Rockwell C

Jan 1, 1948

By W. Crafts, J. L. Lamont

Studies of the effect of composition of steel on hardenability by Grossmann,' and as-quenched hardness by Field2 and by the authors, have made it possible to predict the results of quenching when the composition and cooling rate are known In order to extend the application of the hardenability calculation to the quenched and tempered condition in which steel is finally used, a survey has been made of the hardness changes caused by tempering. From this study a method has been developed for the prediction of hardness and tensile strength of steel in the tempered condition. The method of calculation was developed from Rockwell C hardness tests on quenched and tempered Jominy specimens and is expressed in Rockwell C hardness units. It is of an additive type in which the degree of softening from as-quenched hardness is estimated. Tem-pred properties may be calculated within about plus or minus 5 Rockwell C hardness or plus or minus 15,000 lb. per sq, in. tensile strength. This degree of accuracy is less than that necessary for the control of heat-treatment, but is adequate for the comparative evaluation and selection of alloy steels. The formula indicates that tempered hardness is primarily dependent on as-quenched hardness and, as in the hardening reaction, the progress of tempering is controlled mainly by the carbon content. Alloys tend to retard softening by a secondary hardening mechanism in which the alloy appears to migrate from ferrite to the carbide phase. The factors for the effects of alloys in tempering vary so much from the effects of alloys in hardening that different steels of equivalent hardenability may, after like heat-treatment, differ considerably in tensile strength. Procedure In developing the method for calculating tempered Rockwell C hardness, simple and complex steels were tested over a range from 0.08 to 0'65 per cent carbon and up to 2.68 per cent manganese, 2.18 silicon, 3.50 chromium, 4.94 nickel, and 1.06 molybdenum. The steels were made as small induction-furnace heats at the Union Carbide and Carbon Research Laboratories, Inc' The accuracy of the method was finally checked on a variety of carbon, low-alloy and high-alloy types of heat-treating steels produced under commercial conditions. The method was based on a study of tempered Jominy bars, and its validity was tested by correlation with the center hardness and tensile strength of oil-quenched and tempered bars from 1/2 to 4 in. in diameter. The method of calculation was derived from the differences in Rockwell C hardness between as-quenched and quenched and tempered Jominy specimens. Prenormalized Jominy hardenability speci-menS quenched from a normal temperature for austenitizatios were used to obtain a range of as-quenched Rockwell C

Jan 1, 1948

By G. K. Burgess

(New York Meeting, October, 1913.) 1. COOLING AND HEATING CURVES BY G. V. BURGESS AND J. J. CROWE. § 22. THE results published in Professor Howe's paper 10 of our determinations on the Ac3 and Ar3 points for a series of commercial carbon steels 11 containing manganese in varying proportion, represent the average temperatures found by taking several (4 or 5) heating and cooling curves. The accompanying curves, Figs. 6 and 7, are, for each steel, the first heating and cooling curves as obtained by' the inverse-rate method of Osmond, using a cylindrical chronograph sensitive to -0.1 sec. for recording .time. Simultaneous observations were also taken by the differential method with a platinum neutral and plotted by Rosenhain's derived differential method and gave substantially the same results, the curves having sensibly the same contours in both cases.12. The observations were taken in vacuo on cylinders 5/8 by 1 in. in length bored to center with a 1/8-in. hole to receive porcelain insulated thereto-couple, and inclosed in an out- and in-glazed Berlin porcelain tube heated electrically by, platinum foil wound on the tube. The vacuum was usually better than 0.1 mm. The heating and cooling of the furnace was automatically controlled by a salt-water rheostat with shaped electrodes, giving a uniform rate of heating and cooling.

Jan 6, 1913

The plans for the activities of the Petroleum Division for the coming year do not differ materially from those of the past several years. The fall meeting is scheduled for Oct. 12 and 13 and is to be held at Tulsa, Oklahoma. The Division, of course, will take part in the annual meeting of the Institute at New York. A fall meeting will also be held in California at approximately the same time as the meeting at Tulsa. A number of papers are to be presented at the two meetings simultaneously. The various committees are at work arranging the programs. The Division will continue to be active in its various fields of endeavor, such as stabilization, production reviews, and economics, but special stress is to be laid on the engineering and research fields. In the past the Division has served as a forum for open and frank discussion of problems confronting the engineers in the oil industry. It is hoped that it will continue to function in this capacity. Papers presenting original ideas and extending the boundaries of knowledge and understanding in the field of petroleum production will be welcomed. Members who have interesting information to contribute should not wait until called upon by one of the Committees, but should offer a paper at the earliest opportunity. The past year has seen a decided strengthening of the control over production, with prospects of even more rigid control in the future. It is essential that production programs under such control be carefully planned and it is highly desirable that petroleum engineers take an active part in the planning, to insure efficient production of oil and minimize the waste of this natural resource. At a time like this, when it is difficult to keep the production of oil within reasonable limits, it may seem unnecessary to improve the efficiency of production methods, but, as has been aptly said, the trouble is not that we have too great a reserve of oil but that we are producing tomorrow's oil today. Therefore it behooves those who are entrusted with the engineering and scientific phases of production to learn how to get the greatest yield economically possible from the present and future fields in order that we may enjoy the advantages of petroleum products for a long time to come.

Jan 1, 1934

By D. B. Hobbs, L. W. Kempf, R. S. Archer

SILICON is one of the most important elements in the metallurgy of aluminum. It is always present in small amounts in the ordinary grades of "pure" aluminum, and hence in all alloys made therefrom. Within the last few years binary alloys containing up to 13 per cent. of silicon have come into extensive use for castings. Silicon is also added, beyond the amount present as an impurity, in alloys containing one or more other elements such as copper, manganese, magnesium and nickel. The binary aluminum-silicon alloys are not yet heat treated to any extent in commercial practice, although, as will be shown, their properties are affected to a very considerable degree by heat treatment. There are other aluminum alloys that develop higher strength, but the special characteristics of the silicon alloys may well lead to the application of heat-treating processes on a commercial scale. The role of silicon in the heat treatment of aluminum alloys is more important than would be indicated by consideration of the binary alloys alone, because many of the alloys that are heat treated in regular commercial practice contain some silicon in addition to that derived from the aluminum ingot as an impurity. Among these may be mentioned the heat-treated 195 alloy castings, and the wrought alloys 25S, Special 17S and 51S of the Aluminum Co. of America, and the German wrought alloy, Lautal. It is the purpose of this paper to present the results of experimental work and the conclusions derived therefrom regarding the heat treatment of the binary aluminum-silicon alloys. The products heat treated included forgings, chill castings and both "normal" and "modified" sand castings. REVIEW OF LITERATURE The literature on the heat treatment of aluminum-silicon alloys is not very extensive. The following review gives the principal references of which the authors are aware, in which appreciable information may be found.

Jan 1, 1928

By Otto H. Henry, J. J. Cordiano

THOUGH powder metallurgy is one of the oldest of metallurgical processes, it is in its infancy as a branch of the modern field of metallurgy. As early as 3000 B.C., the ancients produced implements and weapons of iron by reducing iron ore in a charcoal fire and forging the resultant sponge while still hot into the desired shape. Melting and casting soon superseded the powder metallurgy practice, and it was not until the turn of the twentieth century that powder metallurgy was applied to the commercial manufacture of tungsten lamp filaments. From this beginning, the use of the powder metallurgy process spread to the manufacture of porous oil-impregnated bearings, cemented carbide tools, contact points, diamond grinding wheels, clutch facings, starter brushes, resin-bonded radio cores, magnets, metallic filters, and other parts. More recently, and particularly during the present war, there has been a definite trend toward the manufacture of machine parts by this process in competition with the more conventional fabricating methods. Notwithstanding these many developments, scientific progress has been slow. While many articles on powder metallurgy have appeared in the press and various publications, there have been too few contributions to our technical societies, with the result that there is a dearth of the type of information necessary for the full development of this science. It is of primary importance that the results of research and development be freely disseminated if powder metallurgy is to realize its fullest potentialities. PURPOSE OF INVESTIGATION Excluding the refractory metal field, all commercial powder metallurgical products made by a cold compressing and sintering operation contain voids. These voids can be substantially eliminated by subsequent severe working and heat-treatment, but such practice has not proved economical in most applications. By applying heat during the compressing operation, plastic deformation of the powder particles is substantially increased, and the resultant compact or briquette is practically free of voids. However, hot-pressing has many attendant problems, which at present preclude its use in the manufacture of precision parts. The more important of these are to devise: I. A die steel capable of withstanding high pressures at elevated temperatures. 2. A high-temperature lubricant capable of preventing excessive die wear and welding of the compact to the die walls. 3. A method of retaining a neutral or reducing atmosphere in the compacting zone of the die assembly. 4. A means of ejecting the hot-pressed specimen into a neutral atmosphere until reasonably cold.

Jan 1, 1945

By R. H. Harrington

The definition of precipitation-hardening1 is well understood and its principles have been subjected to study for some time. However, the variation of properties with double aging, combined with strain-hardening, gives promise of new and useful phenomena. Properly to understand these distinctions, definitions of these terms are necessary. Precipitation-hardening1.—This reaction usually depends upon an alloy having such a composition that it consists only, or in major part, of but one phase, a solid solution, at a high temperature, so that, upon slow cooling, this solution breaks down into two phases, the solid solution and a compound. By heating the alloy to the temperature for maximum solution of the compound, quenching, and reheating to a suitable lower temperature for critical dispersion precipitation of the compound, useful properties of the alloy may be developed to a maximum. Double Aging.—Dougle aging in part is similar to the process for precipitation-hardening, consisting of heating a precipitation-hardening alloy to the solution temperature, quenching, reheating to the suitable dispersion precipitation temperature, strain-hardening, and again reheating to a suitable temperature to develop certain useful properties to a maximum. The strain-hardening may be induced by two methods: (I) a rate of cooling from the first reheat may suffice to strain the solid solution lattice of the alloy; or (2) the alloy may be cold-worked to a suitable degree between the two reheats. Pkecipitation-hardening of Copper-cobalt-beryllium Alloys1.2 The composition of principal interest is that of 2.6 per cent Co, 0.4 per cent Be, 97 per cent Cu. The alloy has been developed commercially and, with certain reasonable precautions, ordinary brass-foundry practice suffices to produce an alloy of high quality. Preliminary Precipitation-hardening Study.—Samples were cut from a I-in. round rod cast in a graphite mold. These samples were then

Jan 1, 1937

By J. D. Doherty

That America's great coal deposits eventually will be our principal source of liquid as well as solid fuels is generally accepted. Moreover, the day when synthetic oil from coal will begin to supplement our petroleum supplies does not appear to be far off. The American petroleum industry has not spared effort or expenditure in its attempt to keep pace with the demand for oil, and recent production has exceeded expectations. However, the rapidly rising demand for liquid fuels plus the increasing difficulty of finding and developing the new oil needed even to maintain present production rates make it highly unlikely that oil from domestic wells can fully meet future oil requirements. Therefore, it appears that one or more of the following courses must be followed: 1. Curtail oil consumption. 2. Increase imports. 3. Develop new sources such as synthetic liquid fuels.

Jan 1, 1949

By Sidney Sigel, J. Gardner Brooks, Irvin R. Kramer

In 1942 Grossmannl proposed that the hardenability of a steel may be calculated from its chemical composition by considering the base hardenability associated with its carbon content and grain size and multiplying this base by factors for each element present. Since Grossmann's original publication, several investigaton2-6 have reexamined the multiplying factors for the individual elements and in general have found that the multiplying principle is valid. However, some of the individual factor curves developed have been in poor agreement. Inasmuch as the carbon-factor curve obtained by Grossmann was dependent Lipon the factors for all the other alloying elements present in the steel, it logically followed that his results were in need of correction in the light of the new data available for manganese, silicon, and the other alloying elements. Furthermore, in order to avoid the possibility that errors in the manganese, silicon, or other curves might influence the carbon-factor curve, investigation of iron-carbon alloys containing little or no manganese and silicon was necessary. That the effect of carbon on hardenability was greater than indicated by Grossmann is shown by a comparison of the diameters of completely hardened rounds of iron-carbon alloys with the ideal critical diameter calculated from Grossmann's factors. These alloys have a greater hardenability in a finite quench than predicted by Grossmann's factors for an infinite quench (Table I). Among the other important variables that were in need of further investigation were the effect of deoxidation practice on the grain-size correction curves and the effect of stable carbide-forming elements on the depth of hardening. Most Of the work by Kramer, Hafner, and Toleman4 was done on silicon-killed steels. It was not known whether Gross-mann's grain-size correction curves, determined on aluminum-killed steels, was valid when applied to steels with different deoxidation practice. More data on the

Jan 1, 1947

By J. Gardner Brooks, Sidney Sigel, Irvin R. Kramer

In 1942 Grossmannl proposed that the hardenability of a steel may be calculated from its chemical composition by considering the base hardenability associated with its carbon content and grain size and multiplying this base by factors for each element present. Since Grossmann's original publication, several investigaton2-6 have reexamined the multiplying factors for the individual elements and in general have found that the multiplying principle is valid. However, some of the individual factor curves developed have been in poor agreement. Inasmuch as the carbon-factor curve obtained by Grossmann was dependent Lipon the factors for all the other alloying elements present in the steel, it logically followed that his results were in need of correction in the light of the new data available for manganese, silicon, and the other alloying elements. Furthermore, in order to avoid the possibility that errors in the manganese, silicon, or other curves might influence the carbon-factor curve, investigation of iron-carbon alloys containing little or no manganese and silicon was necessary. That the effect of carbon on hardenability was greater than indicated by Grossmann is shown by a comparison of the diameters of completely hardened rounds of iron-carbon alloys with the ideal critical diameter calculated from Grossmann's factors. These alloys have a greater hardenability in a finite quench than predicted by Grossmann's factors for an infinite quench (Table I). Among the other important variables that were in need of further investigation were the effect of deoxidation practice on the grain-size correction curves and the effect of stable carbide-forming elements on the depth of hardening. Most Of the work by Kramer, Hafner, and Toleman4 was done on silicon-killed steels. It was not known whether Gross-mann's grain-size correction curves, determined on aluminum-killed steels, was valid when applied to steels with different deoxidation practice. More data on the

Jan 1, 1947

By G. L. Oldright, T. B. Brighton, C. M. Dice

The base bullion from the lead blast furnace contains varying amounts of the impurities left in the smelter feed by the concentrator, regardless of the method of smelter operation. These impurities may be held in part in mechanical suspension rather than being present as true alloys. However, usually there is little free space in the crucible in which to separate these drosses before the bullion is taken from the lead well. When such a dross is melted in a laboratory crucible and allowed to cool, the products obtained are lead bullion, speiss, and matte in well separated layers. Typical analyses of layers are: Analyses. Per Cent Element Bullion Speiss Matte Pb.............................................. 92.0 41.2 38.3 Cu.............................................. 2.4 36.3 40.6 As............................................... 4.0 16.5 4.3 Sb............................................... 0.7 0.2 0.4 S................................................ 0.6 1.9 13.1 Fe............................................... 0.0 0.0 0.0 Totals......................................... 99.7 96.1 96.7 The absence of iron in these products drossed from the blast-furnace bullion proves that the impurities for the greater part are not simply finely divided blast-furnace speiss or matte that has been dissolved or dispersed in the lead, but are held in solution by the liquid metal and rise to its surface as infusible compounds when the temperature of the bath is lowered. In general, the drosses made locally are metal sulphides and arsenides and not oxidized compounds. The large content of metallic lead also does not seem to be retained because of oxidized compounds

Jan 1, 1937