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Jan 1, 1951

J. R. Lane (Metals Research Laboratory, Washington)—A new type of deformation called "kinking" has recently been described. Is there any relation between the "rumpling" described in this paper and "kinking?" D. C. Jillson (author's reply)—Both are manifestations of bending about [210] axis. The difference is one of degree. W. C. Ellis (Bell Telephone Laboratories, New York) —Some observations of deformation in zinc recorded in this paper may be applicable generally to flow in metals. One of these, deformation in torsion without evidence of slip or twinning in the early stages and with startling ease, when the twist is about the hexagonal axis, adds another method of flow to the presently increasing list of mechanisms. This illustrates again that a crystal will utilize any realizable process to flow and relieve stress. The process is not necessarily classical directional slip—& this case, it is rotational slip. The question naturally occurs: Will face-centered cubic metas stressed by twisting about an octahedral axis flow in a similar manner by rotation on an octahedral plane? I would like to ask Dr. Jillson if he has made any experiments or knows of any experiments of this type on face-centered cubic metals? Face-centered cubic metals possibly would behave differently from zinc, since, for one thing, the stacking sequence is different for the two structures. The results of such experiments, however, would be instructive in providing more information about deformation processes. D. C. Jillson—Dr. Roy E. Swift, working in the Hammond Laboratory at Yale, performed a twist test on a single crystal of brass. The work has not been published, and I do not know the crystallographic direction of the axis of the specimen used. Lo-ching Chang (Columbia University, New York)— Observations similar to Figs. 1 and 2 of the paper were obtained by us during the bending and unbending of an orthorhombic Au-Cd alloy.'l This orthorhombic alloy is the product of diffusionless transformation from a single crystal of p Au-Cd alloy (CsC1 structure) containing 47.5 atomic pct Cd on cooling to about 60 "C.62 Referring to the effects of annealing, has the author tried any loilg time high temperature anneal, such as 150 to 200 hr at 40O°C? D. C. Jillson—No. C. Crussard (Ecole des Mines, Paris: France)—I

Jan 1, 1952

G. A. Moore—The tin-fusion method has been a very favorable possibility for many years. The authors apparently have settled the question that delayed the method for a long time by showing that no hydrogen is absorbed in the tin. This, of course, is very important. I want to make a few remarks concerning the absolute accuracy of analysis, which must be the final basis for deciding among the various methods. From the figures in the paper, there seems to be some re-maining slight discrepancy on the actual amount of hydrogen present in various samples which may be presumed essentially identical. (This is of the order of the precision of individual analyses but appears in averaged results.) From the analyst's viewpoint, the tally of hydrogen content can be regarded as occurring in three portions. First is a large portion which comes off easily and automatically during sample storage and later on heating in the apparatus. This is fairly easily analyzed. Second is an item which may be either positive or negative in the tally sheet. In warm or hot evolution, this is a portion which, in practice, can never be re-

Jan 1, 1951

Lester Guttman (General Electric Research Lab-boratory)—Seybolt has measured the thermodynamic activity of silicon in dilute solution in a iron. The anomaly which appears at 800 °C in the approximate range 1 to 6 wt pct Si is most naturally attributed, as Seybolt has done, to the existence of a region of

Jan 1, 1960

A. Blainey (Ministry of Supply, Atomic Energy Research Establishment. Hnrtoell. England)—With ref- erence to the published work of Hausner et al. on the powder metallurgy of zirconium, it will be of interest to summarize briefly the results of preliminary work we have carried out on this subject at A.E.R.E., Harwell. For the early experiments we used zirconium

Jan 1, 1953

Impact Transition Temperatures of Some Pearlite-Free Mild Steels As Affected by Heat Treatments in the Alpha Range H. P. Tardif (Canadian Armament Research and Development Establishment, Quebec)—Mr. Josefsson is to be congratulated for his study of a most difficult subject and for the theories proposed to explain the re- sults. One point which, however, might not have received proper attention is that of the shape of the stress-strain curve at the yield point of quenched and furnace-cooled specimens and of specimens strain aged

Jan 1, 1956

R. L. Fleischer (Department of Metallurgy, Massachusetts Institute of Technology)— The authors have presented valuable observations of oehavior of aluminum at intermediate and high temperatures. I should like to consider their interpretation of the appearance of cross slip plane traces in sample B-3 as partly due to "bending of the crystal due to grip constraint." Because bending moments might be set

Jan 1, 1960

Jan 1, 1958

P. L. Pratt (University of Birmingham, Birmingham, England)—The author has measured the hardening effect of isolated edge and screw dislocation boundaries in a remarkably elegant manner, and he proposes that the detailed structure of the boundary determines its effectiveness as a barrier to slip although "there are still unknown details of the distribution which may be extremely important." On p. 678 the author states "that for a good crystal (one having a yield of about 30 psi) a change in annealing temperature from 300" to 400 °C resulted in a negligible shift in the level of the stress-strain curve." Is this in agreement with the results of the earlier paper by Li, Washburn, and Parker8 in which such a change of temperature produced notable hardening in crystals with a yield of about 30 psi? Or were these earlier crystals, of the same nominal purity, less perfect than those used in this work? The experiment illustrated in Fig. 15, p. 681, shows that the boundary has sharpened after annealing at 400 °C, the temperature at which the hardening effect first becomes apparent. Did the author verify that no sharpening of the boundary occurred at, say, 300 °C where no hardening was found? This would seem to be an important check on the proposed mechanism, especially since zinc of this purity should polygonize at temperatures well below 400 °C within the annealing times used here. There seem to be at least two alternative explanations which could fit these facts: 1—The boundary may sharpen at 300 °C or even lower temperatures but be unable to contribute greatly to the hardening until jogged by thermal vacancies and other impurity atoms after 400 °C anneal. This mechan- ism, discussed in the earlier paper,' is believed to account for the thermal hardening observed by Blank'" in NaCl, as stated elsewhere: and by results from recent experiments which tend to confirm this view. 2—The dislocations in the diffuse boundary may be locked by impurity atoms at 300 °C and thus only sharpen the boundary at 400 °C with the aid of thermal vacancies. In this case it would be difficult to distinguish between the two sources of hardening (sharpening or jogging), using metal of this purity. Jack Washburn (author's reply)—The author wishes to thank Dr. Pratt for his discussion. In connection with his first comment, it should be pointed out that the temperature of testing in the present series of experiments was —196°C, whereas, in the earlier experiments he referred to,' it was 20°C. Therefore, the yield values should not be directly compared. It is likely that the crystals used in the present work were initially more perfect macroscopically than the large shear specimens used previously. The small size of the test section in the kink specimens made it possible to select regions of the large crystals, from which they were acid-cut, that were free of observable small angle boundaries. The sharpening of a microscopically diffuse boundary such as that in Fig. 15 begins in zinc of this purity well below 300°C. However, it is probably not justified to conclude that because a boundary looks sharp under the microscope it has attained the ideal structure. The author agrees with Dr. Pratt that jogging of dislocation lines is one of the structural features of a small angle boundary that should be important in determining its strengthening effect. More detailed information concerning the changes in boundary structure as a

Jan 1, 1956

Jan 1, 1953

Jan 1, 1957

DISCUSSION, M. Cohen presiding A. H. Geisler and D. L. Martin (GeneTal Electric Research Laboratory, Schenectady, N. Y.)—We were rather interested to note the author's conclusion that the cubic to tetragonal transformation may be of the second order, for we have been able to show that the order-disorder transformation in an analogous alloy system is a first-order transformation with a discon-

Jan 1, 1952

P. Herasymenko (New York University, New York) —The authors' experiments on equilibria between water vapor and liquid synthetic slags represent a valuable contribution to our knowledge of the nature of liquid slags. They can be regarded as a proof of ionic splitting of water molecules dissolved in slags. The assumption that water dissolved in slag was com- pletely ionized was made in my report on hydrogen equilibria in steelmaking as early as 194010. In that paper, the first systematic data were given on the content of ionized hydrogen in acid and basic open-hearth slags. The paper probably escaped the notice of the authors, although they mention the articles published later by other investigators who reported erratic and

Jan 1, 1958

T. L. Joseph (University of Minnesota, Minneapolis, Minn.)—Mr. Killian is to be commended for his inquiry as to why a decrease of 15.3 pct in coke consumption was accompanied by a decrease of only 1.9 pct in the CO/CO, ratio of the top gas. Although I encouraged him in his efforts to find a more significant and meaningful carbon-gas ratio, the method, calculations, and conclusions originated entirely with the author. Whether we agree entirely with the assumptions underlying his corrected ratio, I think we can all agree that a better ratio is needed, and that he deserves credit for recognizing the need and for doing something about it. To be most useful, the CO/CO, ratio for the top gas should reflect the way in which the carbon is gasified in the furnace, particularly the degree of oxidation and the extent of heat release. The effect of CO, from the decomposition of the limestone and the effect of the reaction of CO and water vapor in the upper part of the furnace on the quality of top gas should be isolated from the effect of more basic reactions such as ore reduction and solution loss. The reduction of sufficient iron oxide to produce a ton of pig iron and the accompanying changes in the proportions of the carbon gases can be expressed on a mol basis as follows: 16.5FeA + 16.5CO - 33FeO + 16.5CO, [1] 33FeO + 33.0CO = 33Fe + 33CO. [2] The CO, from eq 1 normally escapes from the furnace because it does not react with coke at the temperature of its release. However, as much as 50 pct of the CO, from eq 2 may react with coke because it is released at temperatures above 1000°C: 16.5CO. + 16.5CO2 = 33CO [3] Thus we see that the gasification of 16.5 mols or about 200 lb of C in solution loss will regenerate as much CO as is required for the last stage of reduction. The pronounced effect of reaction 3 on the final proportions of CO and CO, in the gas stream is obvious. It also follows that reaction 3 materially alters the heat release but it cannot be entirely eliminated in Lake ore practice. A previous study indicates that 100 lb of solution loss may be necessary to maintain the reducing power of the gas. A reduction of 100 lb from the normal level of 200 lb would mean that over 1,-000,000 additional Btu are released in the process. The 100 lb of additional carbon which will be burned at the tuyeres will release 437,000 Btu and the absorption of 583,000 Btu by eq 3 would be prevented. One of the chief objectives of sized ore burdens and more uniform distribution of the gas stream is to minimize solution loss by completing reduction higher in the furnace and in turn to release the maximum amount of heat from the carbon charged. It was odd, indeed, to find that the use of sized ore and sinter in the careful tests reported by Dobscha had changed the CO/CO2 ratio very little. The author has stressed the close correlation between his corrected CO/CO, ratio and production. A correlation of fuel consumption and the CO/CO, might be more logical. Fuel consumption on the prepared ore burden decreased 15.3 pct whereas the corrected CO/CO2 ratio decreased 19.0 pct. Although this agreement between the reduction in fuel and the reduction in corrected CO/CO2 ratio is not as close as the correlation with tonnage, it indicates the corrected ratio is superior to the normal ratio which decreased less than 4 pct. Some adjustment should be made for the reaction: CO + H2O = CO2 + H2 —700Btu [41 because there is evidence to indicate that about one half of the hydrogen is formed in the upper 21 ft of

Jan 1, 1953

R. W. Guard (General Electric Co., Schenectady)— The method of fractional replication discussed by the author has proven very valuable to us in applied research connected with alloy and process development where many of the same experimental difficulties exist. Several of our experiences may be of assistance to those who want to apply the method in these fields. Contrary to the author's observation that interactions are rarely significant, we have found in a number of cases that first order interactions exist which are significant and metallurgically important. Because of this difference there are two further precautions which should be taken in order to minimize the difficulties from this point. First, in evaluating the importance of

Jan 1, 1957

E. Hill, South Norwalk, Conn. (communication to the Secretary*) :—The phenomenon described by Dr. Ledoux, involving an apparently abnormal high temperature in the air-cylinders of compressors, has not been, so far as I know, discussed in technical literature. The common formula for the adiabatic compression of dry air does not account for heat suficient to flash ordinarily decent cylinder-oils, nor do the text-books include in their theoretical statements any quantitative consideration of the effect of leaks in the ideal machines which they contemplate. This lack I have endeavored to supply by preparing, in the form of a circular, for the use of the customers and correspondents of the Norwalk Iron-Works, a brief mathematical

Jan 1, 1904

Adolph Greiner, Seraing, Belgium:—I have nothing special to add to Professor Hubert's paper except to say that there are some little things that it would be well to have corrected when the paper comes to be published. In dealing with the thermal efficiency of the engine, you will find that the 29.84 per cent. was a very high one. Professor Hubert has forgotten those engines built under the Cockerill type, but he has referred to them in Appendix 11. At our works at Cockerill we have built 63 engines, giving 63,000 h.p., and the other companies who have received licenses have built 113 engines, making 103,000 h.p., and aggregating 176 engines and 166,000 h.p. Eight years ago I had the pleasure of giving to the Institute the results obtained up to that time. Since then a good many engines have been constructed. In 1898 I thought a blast-furnace producing 100 tons of pig iron would allow 3,000 h.p. Professor Witz and Professor Hubert show that with the same production of pig the new engines take 3,800 h.p. out of the gas. At present at Cockerill we make 700 to 800 tons of pig iron per day, and we hope to have 26,000 h.p. in a few years. At present we have only half of that in gas-engines, but we hope to have in five or six years all the gas out of these furnaces to the number of 25,000 or 26,000 h.p. Tom WEstGarth, Middlesbrough, England :—My contribution is not a paper in the ordinary sense of the word, because I am sure you will agree with me that what I have written is only supplementary to the other two papers. The notes are schedules of the larger-size gas-engines built by British engine-makers, of 500 h.p. and upwards. If you look at the schedules you will find that in England gas-engines have become quite ordinary motors for a good many purposes. It was at first thought that gas-engines were troublesome, and ill-

Jan 1, 1907

R. V. NorHis, Wilkes-Barre, Pa. (communication to the Secretary*) : The electric-haulage plant of the Short Mountain Colliery of the Lykens Valley Coal Co., mentioned by Messrs. Stoek and Harris as the earliest underground electric plant in the United States (and, I believe, the second in the world), was started July 23, 1887. The plant, designed by W. M. Schlessinger, consists of two motor-cars, each weighing about 5 tons and equipped with a 32-h.p. Union Electric Go. motor. The original general construction of the motor-cars is shown by Mr. Stoek; but they were rebuilt, the same year, with some important improvements in design; and, except for strengthening the frames and replacing the original pig-iron weights by a casting, they have not been greatly changed since that time. The generating-plant consists of two Union Electric Co. dynamos of 65-h.p. each, driven by an old 18- by 48-in. plain slide-valve engine; the ordinary voltage is 450 and the amperage varies from 40 to 200; the average indicated h.p. of the engine is about 75, with a steam-consumption of about 75 lb. per i.h.p. per hour; and as the cost of steam at this colliery is 8.11 cents per 1,000 lb.,the steam-cost per day is about $4.56.

Jan 1, 1904

David T. Day, Washington, D. C.: The paper of Mr. Adams is chiefly valuable because it emphasizes the ease with which petroleum can migrate in the earth's crust. Concerning this migration, I have little faith in the rôle of water as a carrier of gaseous or liquid hydrocarbon, suspended or mixed in the water in any way. My lack of faith is due to observation of

Jan 1, 1903

William Kent, New York, N. Y.:—The Institute may congratulate itself on the opportunity of reading the splendid address of President Brunton. It is an admirable summary of the progress that has been made in the mining and metallurgical arts in recent years. The paper rightly gives the chief credit for this progress to the aid which has been rendered to these arts by the advances in mechanics, chemistry, and electricity. It is notable that most of the headings in Mr. Brunton's address refer to the work of the mechanical engineer, the electrical engineer, and the chemist, rather than to that of the specialist in mining-operations. It seems that the most successful mining engineer of the present day is the one who makes the most intelligent application of the inventions and designs of engineers and others who are not directly engaged in mining. A tabulation of the headings of the address, grouped as below, shows this most clearly. Work of the Mechanical Engineer—Rock-drills, hoisting-machinery, tramming, pumping, ventilation, dredging, Sampling, concentration, briquetting, fume-recovery. Work of the Electrical Engineer—Electric machinery for hoisting, pumping, tramming, lighting and signaling, electric transmission, electric smelting. Work of the Chemist and Metallurgist—Explosives, chlorina-tion, cyanidation, roasting, lead-smelting, and copper-smelting. Work of the Geologist—Economic geology. Work of the Mining Engineer—Mine-mapping, surface-mining, timbering, tunneling; and planning and supervision of the work in general. The mining engineer of the present day, who is in responsible charge of a large plant, finds his chief work not in doing those things he was trained to do as a specialist, but in making use of the knowledge of geologists, chemists, and electrical and

Jan 1, 1910