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By Philip M. Mc Kenna

When a new material becomes available to industry, it is useful to describe its properties as a guide to its most effective application; and when the new material may be produced in compositions having a series of graded properties, tests to select the combination of properties best adapted for various uses are helpful. The class of materials to be considered in this paper are hard tool materials produced by processes of powder metallurgy from hard carbide constituents and various matrices of iron, nickel or cobalt, or alloys of them with tungsten, or tungsten and carbon. The customary use of carbide hard alloys is for metal-cutting tools; although wire-drawing dies, lathe centers, follow rests, grinding rests, burnishers, rolls, extrusion dies, measuring gauges and micrometers, and a number of other tools are also made with these hard alloys as the essential wear-resisting parts. The properties and tests to be considered are those affecting these uses. In the development of tool materials since the industrial revolution we have had carbon tool steels, Mushet steel, high-speed steels, stellites, and now cemented carbide compositions. For an understanding of the latter category of materials their properties and uses relative to the older and more familiar tool materials will be considered. Hardness has been the property of greatest practical interest in tool materials. The word "hardness" is a generalized term lacking definite-ness unless the specific test used is described. However, efforts to explain physical properties as a consequence of chemical bond, and distance between atoms in chemical compounds have been illuminating. This seems the most generalized attack on the problem, and is based upon the idea that atoms in a lattice are held together as the square of the valence and inversely as the square of the distance between the atoms. The compounds compared must all be of the same crystalline arrangement. 100 W2 It is interesting to note the values of the figure 7 A 3 /3for a number of

Jan 1, 1938

By Philip M. Mc Kenna

When a new material becomes available to industry, it is useful to describe its properties as a guide to its most effective application; and when the new material may be produced in compositions having a series of graded properties, tests to select the combination of properties best adapted for various uses are helpful. The class of materials to be considered in this paper are hard tool materials produced by processes of powder metallurgy from hard carbide constituents and various matrices of iron, nickel or cobalt, or alloys of them with tungsten, or tungsten and carbon. The customary use of carbide hard alloys is for metal-cutting tools; although wire-drawing dies, lathe centers, follow rests, grinding rests, burnishers, rolls, extrusion dies, measuring gauges and micrometers, and a number of other tools are also made with these hard alloys as the essential wear-resisting parts. The properties and tests to be considered are those affecting these uses. In the development of tool materials since the industrial revolution we have had carbon tool steels, Mushet steel, high-speed steels, stellites, and now cemented carbide compositions. For an understanding of the latter category of materials their properties and uses relative to the older and more familiar tool materials will be considered. Hardness has been the property of greatest practical interest in tool materials. The word "hardness" is a generalized term lacking definite-ness unless the specific test used is described. However, efforts to explain physical properties as a consequence of chemical bond, and distance between atoms in chemical compounds have been illuminating. This seems the most generalized attack on the problem, and is based upon the idea that atoms in a lattice are held together as the square of the valence and inversely as the square of the distance between the atoms. The compounds compared must all be of the same crystalline arrangement. 100 W2 It is interesting to note the values of the figure 7 A 3 /3for a number of

Jan 1, 1938

By G. E. Keller

In connection with the work of Committee D5, Coal and Coke, of the American Society for Testing and Materials in developing new standards and improving old standards, series of tests were made to check the variance of sample preparation and analysis of American coals. Table I in the "Tentative Method of Preparing Coal Samples for Analysis - 02013-62T" is rather complicated, and the tests were designed to develop data for the simplification of this table. An allowance of 20% of the total variance of sampling and analysis for the sample preparation and analysis steps was used. Also, instead of coals being grouped into ash ranges, they were grouped as washed and raw (unwashed) coals. As a result of these tests, a simplified Table I for Tentative Standard 02013 has been proposed. A standard test for laboratories to check their variance of sample preparation and analysis has been developed. Committee D5 on Coal and Coke of the American Society for Testing and Materials has been making a study of all standards applying to coal for the purpose of improving and bringing them up to date and for breaking some of the existing standards covering a number of tests into single standards. As an illustration, sample preparation is now partly covered in ASTM Designation D492-48, Sampling Coals Classified According to Ash Content, and partly in ASTM Designation D271-58, Laboratory Sampling and Analysis of Coal and Coke. The latter contains, in addition to parts of sample preparation, methods for determining Moisture, Ash, Volatile Matter, etc. Although revision of sampling methods and sample preparation methods are now assigned separately, it is possible that they may end up as one standard. One of the first new Tentative Standards developed as the result of these studies was ASTM Designation D2013, Tentative Method of Preparing Coal Samples for Analysis. Although this method is quite an im- provement over that in the old standards and gives very specific instructions, Table I (attached) is quite complicated and rather hard to understand. In order to take advantage of reduced quantities or weights, it is necessary to know the ash content within rather narrow limits before sample preparation and no distinction is made as to whether the coal is cleaned or uncleaned. No limits of accuracy are assigned to the sample preparation and analysis. The total over-all accuracy of sampling, preparation and ash determination as given in D492-48 has been specified for commercial sampling procedure as follows: "This procedure is intended for an accuracy such that if a large number of samples were taken from a single lot of coal, the test results in 95 out of 100 cases would fall within ? 10 per cent of the average ash content of the sample." Although Appendix 11, Method for Determining the Over-All Variance of Reduction and Analysis in the Tentative Methods for Mechanical Sampling of Coal, ASTM Designation D2234-63T, does give a method for determing the over-all accuracy of preparation and analysis expressed as variance and also the F test, it does not permit the determination of the variance at the various stages of reduction or of the ash determination. It was decided in 1961 to ask a number of laboratories to run a series of tests for the purpose of determining the variance at various stages of reduction and analysis with the view of simplifying Table I of the Tentative Standard D2013-62-T. This paper is a record of this series of tests with recommendations which resulted from the tests. At the same time and preceding these tests the International Organization for Standardization under Committee TC/27 WG 7 was studying the same problem. Tomlinson1 of England and Dr. paul2 of West Germany had made studies giving quite a bit of information. Also Schwerd and coryel13 published some information which was the main basis for the Mechanical Division provision in ASTM Tentative Standard D2013-62T, Table I. In checking with the various laboratories which offered to cooperate in these tests, none was found which used mechanical division through the entire preparation procedure. It was then decided to use riffles at all stages with the thought that if riffles gave satisfactory variances, approved mechanical

Jan 1, 1965

For. the year ending February, 1917 PRESIDENT L. D. RICKETTS,1 NEW YORK, N. Y. PAST PRESIDENTS BENJAMIN B. THAYER,1 NEW YORK, N. Y. WILLIAM L! SAUNDERS,2 NEW YORK, N. Y. FIRST VICE-PRESIDENT SIDNEY J. JENNINGS,1 NEW YORK, N., Y. TREASURER GEORGE C. STONE,1 NEW YORK, N. Y SECRETARY EMERITUS ROSSITER W. RAYMOND, NEW YORK, N. Y. SECRETARY BRADLEY STOUGHTON, NEW-YORK, N. Y.

Jan 2, 1917

For the year ending February, 1917 PRESIDENT L. D. RICKETTS,1 NEW YORK, N. Y. PAST PRESIDENTS BENJAMIN B. THAYER,1 NEW YORK, N. Y. WILLIAM L. SAUNDERS,2 NEW YORK, N. Y. FIRST VICE-PRESIDENT SIDNEY J. JENNINGS 1 NEW YORK, N. Y. TREASURER GEORGE C. STONE,1 NEW YORK, N. Y. SECRETARY EMERITUS ROSSITER W. RAYMOND, NEW YORK, N. Y. SECRETARY BRADLEY STOUGHTON NEW YORK, N. Y.

Jan 3, 1916

By Randall L. Neal

This paper discusses the impact of taxes at the state and federal level on typical on-shore oil and gas exploration economics in the USA. Taxes considered are the windfall profits excise tax, state production (or severance) taxes, state income tax, and federal income tax. Also considered will be market prices for oil and gas in the USA. The effect of government take as a percent of revenue, on rate of return, discounted Payout, and discounted cumulative cash flow is shown on the attached tables. The conclusion drawn is that tax laws, while rarely the most important factor to be considered when drilling a well, can have significant impact on the profitability of oil and gas ventures, and should be considered when determining where to drill. Hypothetical exploration wells were analyzed for the impact of tax laws on project profitability. The results of this study show that when factors other than taxes are postulated to be the same (such as producing rate, capital, operating costs, and prices), cash flow can vary by as much as 68% due to the differences in the tax laws. Other significant findings for the cases studied include: (a) that discounted payout varied by as much as 1.8 years, (b) that rate of return differed by up to 67% and (c) the total tax rate as a percentage of revenue had a maximum variance of 33%.

Jan 1, 1982

By H. C. Schultz

CERTAIN local conditions were known to govern in large measure the successful adaptation of liquid-oxygen explosives to the large-scale blasting at Chuquicamata. The wide variation in hardness of the rock at this mine makes necessary the use of several types of explosives. A locally manufactured, relatively cheap black powder is used in blasting the softer waste and capping material, where a thorough displacement, breaks the ground sufficiently. Before the introduction of L. 0. X., an ammonia dynamite of about 65 per cent. strength was being used exclusively in the harder underlying orebody, where a strong disruptive as well as a displacement effect is required for breaking the ore. The L. 0. X., as developed for quarry work in the United States, has a practically pure carbon cartridge material, and the explosive has an extremely high rate of detonation, which should therefore cause it to usefully develop its full disruptive effect in hard ground. The individual blasts at Chuquicamata are large, black-powder shots which dislodge masses of rock averaging 250,000 tons each, and dynamite shots which dislodge masses averaging 80,000 tons each. It was desirable, therefore, to attempt to displace with L. 0. X. the faster, higher-cost ammonia dynamite used in the smaller blasts. It was not considered practical to attempt to displace the low-cost black powder with L. 0. X., as estimated costs showed no probable saving if this were accomplished. Since it was desirable to continue shooting relatively large blasts for effective operation, it was recognized that larger storage facilities than had been in use would be needed for the liquid oxygen. Because of the difficulty of transporting and discharging large storage containers of efficient design, the better plan appeared to be storage and discharge of the liquid at the place of manufacture, and transportation of the filled soaking boxes to the blast.

Jan 1, 1928

By H. C. Schultz

CERTAIN local conditions were known to govern in large measure the successful adaptation of liquid-oxygen explosives to the large-scale blasting at Chuquicamata. The wide variation in hardness of the rock at this mine makes necessary the use of several types of explosives. A locally manufactured, relatively cheap black powder is used in blasting the softer waste and capping material, where a thorough displacement breaks the ground sufficiently. Before the introduction of L. 0. X., an ammonia dynamite of about 65 per cent. strength was being used exclusively in the harder underlying orebody, where a strong disruptive as well as a displacement effect is required for breaking the ore. The L. 0. X., as developed for quarry work in the United States, has a practically pure carbon cartridge material, and the explosive has an extremely high rate of detonation, which should therefore cause it to usefully develop its full disruptive effect in hard ground. The individual blasts at Chuquicamata are large, black-powder shots which dislodge masses of rock averaging 250,000 tons each, and dynamite shots which dislodge masses averaging 80,000 tons each. It was desirable, therefore, to attempt to displace with L. 0. X. the faster, higher-cost ammonia dynamite used in the smaller blasts. It was not considered practical to attempt to displace the low-cost black powder with L. 0. X., as estimated costs showed no probable saving if this were accomplished. Since it was desirable to continue shooting relatively large blasts for effective operation, it was recognized that larger storage facilities than had been in use would be needed for the liquid oxygen. Because of the difficulty of transporting and discharging large storage containers of efficient design, the better plan appeared to be storage and discharge of the liquid at the place of manufacture, and transportation of the filled soaking boxes to the blast.

Jan 1, 1928

By ERNEST F. . SURCEIARD

work have been published from time to time by the Survey.' A detailed report on the Birmingham district, with maps, has been completed, and will be published within the next year." In the following paper it is aimed to present only an outline of the geologic relations of the ores, since the Appalachian geology of Alabama has been discussed by many previous writers, but to describe rather fully the ore of the Birmingham district, and to discuss its relations and probable extent. IT. OUTLINE OF THE GEOLOGY. 1. Stratigraphy. The pre-Pennsylvanians rocks exposed in and along the borders of the valley-regions of Alabama, range from middle Cambrian to Mississippian (Lower Carboniferous), and at the SW. extremities of the valleys these rocks are overlain by coastal-plain deposits of Cretaceous and Tertiary age. A generalized section of the pre-Pennsylvanian Paleozoic rocks for the valley-regions is given in Table I. TABLE I.-Section of Pre-Pennsylvanian Paleozoic Rocks in Valley-Regions of Alabama. System. Formation and character. Thickness. Ft. Shale and sandstone 300 to 2,200 Carboniferous (Mississippian- Limestone and shale 300 to 800) I Sandstone and shale 50 to 200 1 Fort Payne chert and limestone 100 to 300 Devonian Chattanooga shale 0 to 30 Silurian Clinton (" Rockwood ") shale, sand¬ stone, and iron-ore 200 to 700 Ordovician Chickamauga ("Trenton") limestone.. 200 to 800 Cambro-Ordovician Knox dolomite and chert 1 2,200 to 2,700 basal dolomite 500 to 600 Cambrian Conasauga shale and limestone 1,000" to 1,500 - I a Base not. exposed.

Nov 1, 1908

For the year ending February, 1917 PRESIDENT L. D. RICKETTS,1. NEW YORK, N. Y. PAST PRESIDENTS BENJAMIN B. THAYER,1 NEW YORK, N. Y. WILLIAM L. SAUNDERS,2 : NEW YORK, N.Y. FIRST VICE-PRESIDENT SIDNEY J. JENNINGS,1 NEW YORK, N. Y. TREASURER GEORGE C. STONE,1 . NEW YORK, N.Y. SECRETARY EMERITUS ROSSITER W. RAYMOND, NEW YORK,. N. Y. SECRETARY BRADLEY STOUGHTON NEW YORK, N.Y.

Jan 1, 1917

For the year ending February, 1917 PRESIDENT L. D. RICKETTS,1 NEW YORK, N. Y. PAST PRESIDENTS BENJAMIN B. THAYER,1 NEW YORK, N. Y. WILLIAM L. SAUNDERS,2 NEW YORK, N. Y. FIRST VICE-PRESIDENT SIDNEY J. JENNINGS,1 NEW YORK, N. Y. TREASURER GEORGE C. STONE,1 NEW YORK, N. Y. SECRETARY EMERITUS ROSSITER W. RAYMOND, NEW YORK, N. Y. SECRETARY BRADLEY STOUGHTON, NEW, YORK, N. Y.

Jan 7, 1916

By M. M. Fine

Normally the U. S. produces less than 10 pct of its annual manganese requirement. About 95 pct of domestic consumption is used by the steel industry.' The strategic and critical nature of manganese has been recognized by its inclusion in the national stockpile and by intensified research directed toward cataloging and evaluating domestic manganiferous deposits. The USBM has participated in these activities for many years with field and laboratory studies to assess the extent and potential utilization of domestic manganese ores. One area of particular interest is in the vinicity of Batesville, Ark., where deposits have been mined since 1849 for both manganese and ferruginous manganese ores. Production is centered in Independence County, but deposits are also found in Sharp, Izard, and Stone counties in north-central Arkansas. Miser has described the geology and manganese mineralization in some detail.'. * "he rocks of the area are sedimentary, consisting of sandstone, limestone, shale, and chert. The two formations of greatest importance,' Fernvale limestone and Cason shale, are host rocks of the primary manganese mineralization. Through 1955 the district produced some 230,000 long tons of manganese ore (35 pct Mn or more) and 236,000 tons of ferruginous manganese (10 to 35 pct Mn).5 Most of the ore has been mined from deposits of manganese oxides in residual clays resulting from weathering of the two formations noted above. Concentration methods have been primitive, consisting for the most part of washing. hand picking, and jigging. A significant accomplishment in the district in recent years was the USBM recognition and investigation of the huge manganese potential represented by unaltered Fernvale limestone. systematic reconnaissance of manganiferous limestone and other occurrences has been in progress since 1953 to delineate the extent and tonnage of manganiferous materials. Results of that survey have appeared in two recent publications,1-5 which ascribe to the district an inferred reserve of 166 million long dry tons at a grade of 5 to 6 pct Mn. Most of this was mancaniferous limestone with an estimated content of 5 pct Mn. Specifications: Beneficiation was carried out on a group of manganiferous limestones to develop a way to recover commercial-grade concentrate from this extensive resource. The following chemical specifications were established by the GSA for metallurgical manganese ore acceptable for delivery to the national stockpile: Size specifications were not considered, as it was assumed that the concentrates could be pelletized or sintered. Manganiferous Limestones: Of the 11 samples tested to date, six were taken by cutting vertical channels across beds of limestone outcrops. Diamond drilling through overlying barren chert into unex-posed limestone provided four samples, and the last was a churn drill sample. In general, the samples were dlrk, fossiliferous limestone containing small amounts of braunite, hausmannite, rhodochrosite, massive and micaceous iron and manganese silicates, quartz, barite, and glauconite. The braunite and other manganese oxides partly to completely replaced some of the calcite and fossil material. The calcite was generously stained with mangenese and iron oxides. Phosphorus was present in all samples as collophanite grains, calcium phosphate fossil replacements. or an unidentified manganese-bearing carbonate. The difficulty in separating this complex array of minerals was further complicated by a very intimate association. Although some manganese grains as large as Ik in. were noted, grinding to subsieve sizes would have been necessary to liberate the components. Figs. 1 and 2 are micrographs, at X100, of typical polished sections in which white areas are manganese. gray is gangue, and black areas are surface depressions. By comparison with the 100 mesh opening, it is seen that some of the grains are coarse enough to respond, perhaps to tabling or flotation, but many are obviously beyond the scope of ohysical processing. Partial chemical analyses of the eight samples that were ultimately amenable to concentration are presented in Table 1. BENEFlClATlON RESEARCH Tabling: To take advantage of the presence of sand-size grains, both jigging and tabling were considered at the outset. Jigging was largely ineffective, but tabling achieved a partial recovery from most samples. As an example, the surface material from Baxter Hill was crushed to —28 mesh, hydraulically classified, and the coarsest spigot fraction was tabled to yield a concentrate, middling. and tailing. The latter two were reground to pass 48 mesh, combined with the primary fines, re-classified, and retabled. The middling and tailing were again ground, this time to pass 150 mesh, and deslimed at 20µ in a 3-in. hydraulic cyclone. The cyclone underflow was returned to the table to reclaim a small amount of high-grade manganese. An interesting facet of the gravity concentration developed on certain samples in which braunite was the principal manganese constituent. Since braunite has a Mohs hardness of 6 to 6.5, while the host rock, limestone. is only 3, a differential size reduction took place during crushing, and the

Jan 1, 1960

By Charles Austin

IT has been known for several years1 that certain alloys of the Konal type, containing commercial cobalt (99.32 per cent C0 and 0.42 per cent Ni) and varying amounts of ferrotitanium, exhibit very high tensile strengths at 600°C. However, their pro-portional limits and yield points are rela-tively low. Published data1 for the alloys quenched in water from 950°C. and then tested at 600°C. are summarized in the upper section of Fig. I. Similar specimens that were aged at 650°C. for 72 hr., after quench and prior to testing at 600°C., gave the results shown in the lower section of Fig. I. TABLE I.-Analysis of Material I Percentages Constituent Sample Sample Sample 3125 3124 3123 Si 0.25 0.51 o.6o Fe 4.15 10.70 13.17 Ti I.15 3.58 4.70 Mn 0.30 0.41 0.42 Co (by difference)^ 94.15 84.80 81.71 The cobalt from all three samples, united and tested for nickel, gave 0.54 per cent Ni based on the weight of cobalt. In the present work the investigation of the properties of these materials has been extended by a study of the tensile deforma- tion characteristics in moderately long-time tests at 600°, 700° and 800°C. after quenching from various solution tempera-tures. In addition, some metallographic studies have been made to correlate with the deformation tests, and to obtain in- FIG. 1.-EFFECT OF VARYING AMOUNTS OF FERROTITANIUM (FE2TI) ON PHYSICAL PROPER-TIES OF COMMERCIAL COBALT. (C. R. Austin.1) Upper section. Tested at 600°C. after water-quenching from 950°C. Lower section. Tested at 600°C. after water-quenching from 950°C. and aging 72 hr. at 650°C. FIG. 2.-PORTION OF QUASI-BINARY DIAGRAM COBALT-FE2TI AS DETERMINED METALLOGRAPH-ICALLY. formation on the quasi-binary system Cobalt-Fe2Ti. The material, very kindly furnished by the Westinghouse Electric and Manufac-turing Co. in the form of hot-swaged rods of 3/16-in. diameter, analyzed as shown in Table I. The alloys, when originally made up,1 were based upon an iron-titanium com-pound, Fe3Ti, as indicated by the work of

Jan 1, 1940

By L. S. Darken

It has long been recognized that the driving force in an isothermal diffusion process may be regarded as the negative gradient of the chemical potential (partial molal free energy) of the diffusing substance. This equivalence is exactly analogous to the fact that a mechanical force is the negative gradient of the potential energy. Nernstl in 1888 expressed these driving forces in terms of osmotic pressure, which is directly related to the chemical potential and free energy. The relationship between the diffusivity, mobility and activity coefficient of electrolytes in aqueous solution has been developed in great detail by Onsager and FuossZ with results which have recently been confirmed experimentally by Harned and Nuttall. This interpretation of the driving force in isothermal diffusion has been discussed earlier by the author,4,5 who pointed out4 that "for a system of more than two components it.is no longer necessarily true that a given element tends to diffuse toward a region of lower concentration even within a single phase region"; departure from the behavior of an ideal solution may be so great that the concentration gradient and the chemical potential gradient, or activity gradient, may be of different sign, thus giving rise to "up hill" diffusion. Since, in the discussion of that paper,4 some skepti- cism as to the validity of this conclusion was expressed, it seemed desirable to adduce experimental evidence to support it. Evidence of such diffusion in nonmetallic systems has already been reported. For example, it was observed by Hartley" in a series of experiments in which sodium chloride diffused from a saturated solution in about 5 pct acetone in water into a solution virtually free of salt but with essentially the same acetone concentration. Specifically, a wine glass containing crystalline salt and saturated solution was totally immersed in a large glass cylinder containing the acetone-water solution without salt; the difference in specific gravity was such as to prevent convection. Diffusion of salt was accompanied by a marked depletion of acetone in the wine glass; after 3 days the acetone concentration decreased from 5.37 pct at the top of the glass, where the salt concentration was low (0.93 pct), to 1.84 pct at the bottom where the salt concentration was high (21.64 pct). This "uphill" diffusion was found to be such that the partial pressure (activity) of acetone was essentially equalized throughout the system when a steady state gradient of sodium chloride was maintained. In order to demonstrate the existence of such diffusion in metals, a series of four weld-diffusion experiments was made. In these measurements pairs of steel of virtually the same carbon content, but differing markedly in alloy content, were welded at the end and held at 10500 C for about two weeks. Subsequent analysis showed that carbon had diffused so as to produce an inequality

Jan 1, 1949

"In the mines producing over 500 tons per day, skips have replaced the old method of hoisting ore by cars run onto cages. In the car and cage method, two men (station tenders) trammed the loaded cars onto the one-deck cage, and as the production increased the one-deck cage was increased to two decks and later to four decks. Landing chairs at the underground stations were necessary in this method and were the cause of many serious accidents by being carelessly left in the shaft by the station-tenders when leaving one station for anotherabove. The labor and time occupied in loading the leaving cages were con¬siderable, and, at times of rapid hoisting, four men were necessary in taking off empty and caging loaded cars. This also required at the surface landing, as many as ten men on a shift to remove the loaded cars and replacing them with empties, and tram the loaded ones to the surface ore bins, where the railway cars were loaded.The skips used in Butte are generally of 100 cubic feet capacity and hold five tons of ore, and weigh 7,500 lbs. The cage above, to which the skip is attached, weighs 2,300 lbs. The skips dump automatically into a pocket of 50 tons capacity. Two men are with the skips underground and load them from 125 ton capacity ore-pockets, under each station, the bottoms of the pockets having an inclination of 50 degrees from the horizontal. At the bottom of these pockets a gate is operated by compressed air. The labor of loading the skips amounts only to the opening and closing of a valve in the air-line, the ore running by gravity into the skips.Besides the saving in labor, the use of the skips has removed the necessity of underground landing chairs in the shaft and the accidents which are inevitable where such chairs are used."

Jan 1, 1913

By Howard Martens

HARDNESS behavior of commercial titanium alloys following various heat treating processes has been studied for some time. However, the hardness of such alloys following a definite measured cooling rate from the single phase region has not been reported. Therefore, a series of experiments was conducted on the three alloys: 150A, 130A, and 130B. The manufacturers gave the following compositions for these alloys: Ti 150A: 0.045 pct C, 0.069 pctN, 1.32 pct Fe, and 2.68 pct Cr; RC 130A: 0.13 pct C, and 7.9 pct Mn: RC 130B: 0.11 pct C, 3.5 pct Mn, and 3.2 pct Al. A method similar to that described by Greninger was used, and the cooling rate varied from 6" to 9200°F per sec. The cooling curves were recorded on a Speedomax or a recording oscillograph, and the hardness was measured on a Tukon hardness tester using a Knoop indentor with a 500 g load. The curves of Fig. 1 show the variation of the Knoop hardness with the cooling rate for these three alloys. The alloys 150A and 130B behave in a similar manner, as shown by the curves. In neither of these alloys was it; possible to retain the high temperature ß phases, even by the most rapid cooling rate. The slow cooling rates produced a typical ß structure in these two alloys. As the cooling was increased, these phalses became more finely dispersed and the hardness increased. This increase in hardness with cooling rate continued for the 150A alloy until a rate of approximately 1000°F per sec was reached. At this cooling rate, the structure showed the result of the dif-fusionless transformation of the ß solid solution to the supersaturated a solid solution which is referred as a'. At higher cooling rates, the structure showed no change and the hardness showed no great change, as indicated by the dotted portion of the curve in Fig. 1. The increase in hardness with cooling rate for the 130B alloy continued until a rate of approximately 300°F per sec was reached. At this rate the structure was produced and the maximum hardness was reached. Higher cooling rates caused no marked changes in hardness or structure. The alloy 130A behaved in a different manner, as shown by the curve of Fig. 1. The structure produced by the slow cooling rates was a typical a+ß structure, which became finely dispersed as the cooling rate increased. The hardness increased with cooling rate and reached a maximum at approximately 120°F per sec. At this maximum hardness, the structure showed the result of the decomposition of the ß phase into the ß + phase structure. As the cooling rate was increased, smaller amounts of the at phase were formed and the alloy became softer. For cooling rates of 3000°F per sec and above, the high temperature ß phase was retained and the hardness of the alloy did not change markedly. Acknowledgment This paper presents the results of one phase of research carried out at the Jet Propulsion Laboratory, California Institute of Technology, under Contract No. DA-04-495-0rd 18, sponsored by the Dept. of the Army, Ordnance Corps.

Jan 1, 1957

By R. L. Stephenson

The effect of fabrication variables on the creep-rupture properties of TZM (Mo-0.5 pct Ti-0.08 pct Zr-0.03 pct C), Cb-TZM [columbium-modified TZM (7140-1.5 pct Nb-0.5 pct Ti-0.8 pct Zr-0.05 pct C)], and TZC (Mo-1.2 pct Ti-0.25 pct Zr-0.15 pct C) has been studied at 982º. 1093º, 1204º, and 1315°C for rupture times up to 1000 hr. The creep tests were performed in vacuum creep furnaces, employing cold-trapped oil-diffusion pumps, operating at pressures 2 X 10-7 tory. After-test chemical analyses showed no significant changes in interstitial content. The creep-rupture properties of TZM, fabricated according to current mill practice, were determined in the stress-relieved and in the re crystallized conditions to provide control data. Specimens of TZM, Cb-TZM, and TZC fabricated according to each of two experimental fabrication schedules were then tested. The schedules differed in terms of in-process annealing temperatures and warm -working temperatures. The data make several conclusions evident. Fabrication variables do indeed have a profound effect on the long-time creep-rupture properties of molybdenum alloys. Strengths of these alloys compare very favorably with those of other refractory metal alloys in the temperature range studied. FOR several years we have been engaged in the evaluation of the creep-rupture properties of promising refractory metal alloys. We consider the determination of these properties to 1000 hr at several temperatures necessary for a valid comparison. Such an evaluation indicated that the creep strengths of Mo-0.5 pct Ti and TZM (Mo-0.5 pct Ti-0.08 pct Zr-0.03 pct C) compare favorably with those of other refractory metal alloys. Tensile and recrystallization data of other investigators1,2 show an effect of fabrication variables. More specifically, those fabrication schedules which produce high strength through work hardening exhibit the least thermal stability. A similar conclusion was reported by perkins3 for Cb-TZM. This would lead one to expect that, in terms of creep, those materials showing higher strength at short times and low temperatures would exhibit lower strength at long times and high temperatures. If these expectations were fact, a substantial improvement could be made in these alloys by optimizing their fabrication schedule in terms of their anticipated service temperature. We therefore undertook a study of the effect of fabrication variables on the long-time creep properties of TZM, Cb-TZM (Mo-1.5 pct Cb-0.5 pct Ti-0.08 pct Zr-0.05pct C) and TZC (Mo-1.2 pct Ti-0.25 pct Zr-0.15 pct C). MATERIALS All materials used were supplied by the Climax Molybdenum Co. of Mich. Our original intention was to test the same heat of each alloy in different conditions. Fabrication difficulties prevented this; however, heats with nearly identical analysis were selected. The compositions of the materials used are listed in Table I. All materials were supplied in the

Jan 1, 1970

By Jonathan G. Price

Silver-copper-lead deposits In Precambrian, Permian, and Cretaceous red-bed sequences near Van Horn, Texas, have the following features In common: (1) mineralization controlled by steeply dipping fractures in sandstones, (2) lack of ore in overlying and interbedded limestones, (3) absence of igneous intrusions, (4) sulflide ores without typical hydrothermal gangue minerals, and (5) associated arsenic, molybdenum, zinc, and cadmium but not gold. Ore was probably deposited along fractures by reaction between low-temperature, oxidizing, metal-rich ground waters and sulfide-bearing waters or rocks. Detailed mapping and studies of fracture patterns indicate that mineralization occurred during Basin and Range extensional deformation, thereby postdating major Trans-Pecos igneous activity.

Jan 1, 1984

For the year ending February, 1917 PRESIDENT L. D. RICKETTS,1 NEW YORK, N. Y. PAST PRESIDENTS BENJAMIN B. THAYER,1 NEW YORK, N. Y. WILLIAM L. SAUNDERS,2 NEW YORK, N. Y FIRST VICE-PRESIDENT SIDNEY J. JENNINGS,1 NEW YORK, N. Y. TREASURER GEORGE C. STONE,1 NEW YORK, N. Y. SECRETARY EMERITUS ROSSITER W. RAYMOND, NEW YORK, N. Y SECRETARY BRADLEY STOUGHTON, NEW YORK, N. Y.

Jan 12, 1916

R. F. McELVENNY.- The next item is: "Center and other methods, vs. side charging." That was all discussed in the Carson case, and I do not know but what many of the plants are still using center charging. Some are using side charging. Did I understand that where you use the wet charge it is all side charging on the wet ore? B.-G. C. HONEYMAN.- We were on center charging for about a year with wet ore. R. F. McELVENNY.- Then you went to side charging. Has anyone any remarks to make on side versus center charging? E. A. BARNARD.- We have one side and one center, both on deep bath. It is an experimental proposition so far, but the side charge looks very favorable.. R. F. McELVENNY.- This is with calcine? E. A. BARNARD.- This is with calcine on a floating charge proposition.. They are both water jacket. The charge acts very similar on both center and side charging. The calcine spreads much the same as it does on the center charge. It will run down 75 ft. on the furnace side as well as the center. The advantage is in taking care of secondaries and things of that nature. C. BARDWELL.- Do you get any side wall protection from it? E. A. BARNARD.- No. R. F. McKENZIE.- Do you not project the side wall up to protect the skewback? E. A. BARNARD.- There is a slot projection down around the top of the bath; but the repairs on the side wall have been practically the same; that is, they, have been practically the same as they have on the center charge. A. H. RICHARDS.- A point I would like to make is that if you have any doubt about the center charging, we feel that we get better tonnages and lower fuel ratios and better slags with center charging than we ever got with side. Different kinds of charges would, of course, vary, and I could readily see that if you had the same advantage with deep bath smelting that you mention you would probably get just as good a slag and as good fuel ratios. E. A. BARNARD.- In fact, I think the calcine charge spreads more on the side than on the center charge. A. H. RICHARDS.- If you maintain a deep bath. E. A. BARNARD.- That is one thing we have to be careful about, to hold the charge back.

Jan 1, 1930