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By Jay R. Burns

Two magnesium sand-casting alloys are commonly favored in the United States. These are referred to as H and C alloys (Dow Chemical Co.) or AM265 and AM260 alloys (American Magnesium Corporation). Both are of an aluminum-zinc-manganese type. H alloy contains 6 per cent aluminum and 3 per cent zinc and is characterized by relatively good toughness. C alloy contains g per cent aluminum and 2 per cent zinc and is employed where high yield strength and pressure tightness are required. Examination of magnesium castings poured in Europe and England,1,2 however, demonstrates that H and C alloys are replaced by A8 and AZ91, respectively. That is, A8 represents a magnesium alloy having superior toughness while AZ91 is suitable for high yield strength and pressure-tight applications. The basic difference between the American and European alloys is that the foreign alloys employ a somewhat higher aluminum content and less zinc than is found in H and C alloys. The mechanical properties of the alloys, when divided into high and low-aluminum groups, are quite similar, as determined from separately cast foundry-control type test bars.3 In this paper the decrease of mechanical properties caused by any given amount of microporosity is measured for H, C, A8, and AZ91 alloys. The relative susceptibility of each of the four alloys to microporosity is also determined. Typical mechanical properties and nominal chemical analyses are reported in Table I. [ ] The apparent similarities between the two alloys in each group have led to considerable discussion as to the relative merits of each of the compositions.2 Popular points for comparison between the alloys have been the relative susceptibility of each of the four alloys to microporosity5 and the effect of this microporosity on their mechanical properties. It is primarily intended, in this paper, to show the

Jan 1, 1946

By J. B. Scott, J. L. Popham, H. F. Coffer, J. J. Reynolds

This paper concerns field experiments to define the areal extent, orientation and thickness of an artificial fracture in the Sacatosa field, Maverick County, Tex. The fracture was made by a sand-oil treatment of 176,-000 gal of lease crude containing a fluid-loss additive and 270,000 lb of 20-40 mesh subangular Poteet sand. The well was perforated with a jet gun, consisting of six shots in a single plane. Fourteen test holes were drilled at various locations around the fractured well. Drill-stem tests, Micro and Sonic Logs, coring and sampling of formation cuttings were used to determine the presence of the fracture in these holes. The test holes were drilled at distances up to 250 ft in a radial pattern around the fractured well. In addition to fracture areal extent and orientation, sand grain size before and after fracturing, erosion of perforations and fracture thickness were studied. INTRODUCTION The orientation,12 areal extent3, 4 and thickness5-9 of artificially induced fractures in reservoir rock by hydraulic means have been discussed in great detail in the oil industry in recent years. Methods for initiating vertical"' and horizontal" fractures have been tested in the laboratory and the field. Although the methods used give successful well stimulation, good field data on the physical characteristics of the fracture are lacking in the literature. It is recognized generally that properties of a fracture, such as thickness, sand placement in the fracture" and shape, may vary from reservoir to reservoir. This paper gives data on size, orientation and sand placement in a large fracture initiated in a single plane in Sacatosa field, Maverick County, Tex. It is not intended as a speculative study; rather, it is restricted to actual field data on fracture properties. No attempt is made to prove that the same type of fracture occurs in all wells. The field procedure was to drill 14 test holes at various locations around the fractured well. By employing several different testing techniques, the presence of the fracture and some of its characteristics were determined. These techniques as well as the results obtained are discussed in detail in this paper. DESCRIPTION OF FRACTURE TREATMENT N. J. Chittim Well No. 37-1, completed in the San Miguel No. 1 sand, Sacatosa field, Maverick County, Tex., was chosen for the field study. The San Miguel sand is a tight, well consolidated sandstone with an average porosity of 23 per cent. The permeability ranges from 0.1 to 10 md, with a median permeability of 2.3 md. The sand thickness averages 23 ft and is located at depths of 1,150 to 1,700 ft throughout the field.I3 The fracture treatment performed on Well 37-1 was as follows. 1. The well was drilled to a depth of 1,438 ft with native mud, and 51/2-in. casing was set and cemented to the surface. 2. The casing was perforated at 1,349 ft with a fracture-initiating jet gun. This gun consists of six shots, 7/16-in. diameter in a single horizontal plane. The jets were oriented in two groups of three, 180" opposed. The perforating device was designed to initiate a fracture perpendicular to the wellbore.

Jan 1, 1959

By Alden B. Greninger, Alexander R. Troiano

Metallurgists have long believed that martensite in steel forms as plates along the octahedral {111} planes of austenite. Much has been written about mechanisms whereby units of the austenite lattice are pictured as transforming to martensite by shearing movements initiated along the octahedral planes of austenite, supposedly resulting in plates of martensite lying parallel to these planes of shear. A critical inspection of two or three photomicrographs of quenched hypereutectoid steel led us to the conclusion that the orientation habit of martensite, at least in hypereutectoid austenite, could not possibly be octahedral. Inasmuch as recent studies,30,31 of the martensite-type reaction in nonferrous alloy systems have established the irrational orientation habit as characteristic of this type of lattice transformation, the need for a thorough restudy of the crystallography of martensite formation in steel was evident. The present paper reports the results of such a study, extended to include both cementite and some of the products of constant-temperature decomposition of austenite. Also reported are a few of the results obtained from a microscopic and X-ray study of the austempering process in very high-carbon steel. I. The Martensite Transformation Previous Work Microstructure and Crystal Structure of Martensite.—Among the best series of published photomicrographs of quenched steels are those of Whitely,1 Robertson,2 Hanemann and Schrader,3 and Lucas.4 The crystal structure of martensite is body-centered tetragonal, with axial ratio varying from 1 near 0.0 per cent carbon to 1.08 for 1.75 per cent

Jan 1, 1940

By Alden B. Greninger, Alexander R. Troiano

Metallurgists have long believed that martensite in steel forms as plates along the octahedral {111} planes of austenite. Much has been written about mechanisms whereby units of the austenite lattice are pictured as transforming to martensite by shearing movements initiated along the octahedral planes of austenite, supposedly resulting in plates of martensite lying parallel to these planes of shear. A critical inspection of two or three photomicrographs of quenched hypereutectoid steel led us to the conclusion that the orientation habit of martensite, at least in hypereutectoid austenite, could not possibly be octahedral. Inasmuch as recent studies,30,31 of the martensite-type reaction in nonferrous alloy systems have established the irrational orientation habit as characteristic of this type of lattice transformation, the need for a thorough restudy of the crystallography of martensite formation in steel was evident. The present paper reports the results of such a study, extended to include both cementite and some of the products of constant-temperature decomposition of austenite. Also reported are a few of the results obtained from a microscopic and X-ray study of the austempering process in very high-carbon steel. I. The Martensite Transformation Previous Work Microstructure and Crystal Structure of Martensite.—Among the best series of published photomicrographs of quenched steels are those of Whitely,1 Robertson,2 Hanemann and Schrader,3 and Lucas.4 The crystal structure of martensite is body-centered tetragonal, with axial ratio varying from 1 near 0.0 per cent carbon to 1.08 for 1.75 per cent

Jan 1, 1940

By AIME

One of the operations of the J. L. Shiely Co. is quarrying in a hard granite gneiss with intrusions of gabbro or trap. During the winter of 1948-1949 the quarry ramp was lowered about 30 ft and during the 1949 season practically all drilling was done from the quarry floor, developing a face from 72 to 83 ft for the entire quarry area. The performance and cost table shows our record for 1948 and 1949.

Jan 1, 1950

By Edgar T. Wherry

EDGAR .T. WHERRY,* Washington, D. C. (communication to the Secretary ?).-Dr. Pogue's presentation of the facts concerning the emerald deposits is very clear and convincing, and the only addition that I can suggest is a summary of previous theories of origin. He makes it evident that the pegmatite theory is the only one capable of explaining the existing relations, but upon certain details there may be some difference of opinion. If I understand the term pneumatolytic, it does not imply that all the elements concerned in a given deposit were transported as gases, but rather that the crystallization of these elements into the various minerals was favored by the presence of certain gaseous substances, notably H20, C02 and HF. It is highly improbable that the oxides of glucinum, aluminum, chromium, and silicon, which enter into the composition of the mineral emerald could have been transported in the gaseous form. The same is true of the metallic constituents of the parisite and other associated minerals. The explanation suggested, that solutions separated into liquid and gaseous portions, the latter ascending and forming the emerald in the upper portions of the rock only, therefore, seems to me untenable. When two formations exist side by side and one, A, is mineralized while the other, B, is barren, the possible explanations may he classed as (1) chemical, and (2) physical. 1. Some chemical feature of A not found in B might have caused crystallization of certain minerals in the former, which did not appear in the latter. In the present instance both rocks appear to be so similar chemically that no such effect can be looked for. Pogue mentions carbon as a possible precipitating agent, but describes both formations as carbonaceous, so that the difference in the minerals of the two can not be thus explained.

Jan 10, 1916

By James F. Lewis

The hematite iron ore mines east of the Hudson River are confined to a strip of country ten to fifteen miles wide, commencing on the south, near Fishkill, running northeast through Dutchess County, and striking the southeast corner of Columbia County, extending into Litchfield County, Conn., known there as the Salisbury mines, cropping out again at and near West Stockbridge, Lanesboro, and Cheshire, Mass., also in Bennington County, Vermont. The ores are found in beds or deposits and in veins, with a limestone ledge on one side and slate on the other, from six to thirty feet from the surface. Portions of it are quite solid, called rock ore, but

By Frank Firmstone

The indicator cards shown herewith were taken by the writer in June, 1877, from the water-pressure blowing engine of the Longdale Iron Co., at Lucy Selina Furnace, Longdale, Virginia. A description of' this engine with figures, and some indicator cards, was published by Washington Jones, Esq., Superintendent of the I. P. Morris Co.,* in the Journal of the Franklin Institute for May, 1877, to which those desiring a full account are referred, but for convenience the principal dimensions, etc., are given below. The machine consists of a pair of horizontal direct-acting blowing engines, connected at right angles to a common fly-wheel shaft. The blowing cylinders are 4 ft. diameter by 5 ft. stroke; the water cylinders were 18 in. diameter by 5 ft. stroke as built. Both water and blowing cylinders are double acting. The water valves are balanced piston valves, 18 in. diameter, moved directly by eccentrics on the fly-wheel- shaft. Great care was taken to have the areas of the ports and passages at least equal to the area of the working piston. The engine is set about 14 ft. above the tail-race, and the

Jan 1, 1879

By AIME AIME

[SECRETARY'S NOTE.-Since the Committee on Publication of United Engineering Society, will issue a memorial volume re¬porting these proceedings in full, an outline only will be here given. The sessions were held in the Main Auditorium.¬R. W. R.] COMMITTEES. EXECUTIVE.-J. W. Lieb, Jr., Chairman; C. W. Rice, Secretary; John Hays Hammond, Chas. Wallace Hunt, F. R. Hutton, Charles Kirchhoff, T. C. Martin, E. E. Olcott, Chas. F. Scott, Samuel Sheldon, Ambrose Swasey. INVITATIONS.-R. W. Raymond, Chairman; Charles Kirchhoff, Secretary; A; C. Humphreys, Robert W. Hunt, L. B. Stillwell. PROGRAM.-A. R. Ledoux, Chairman; C. W. Rice, Secretary; Theodore Dwight, Chas. Wallace Hunt, T. C. Martin, Ralph W. Pope, Joseph Struthers. WAYS AND MEANS.-James Douglas, Chairman A. R. Ledoux, Secretary; H. R. Brown, J.-M. Dodge, C. L. Edgar, John Hays Hammond, W. M. McFarland, E. E. Olcott, Samuel Sheldon, J. G. White. HISTORICAL AND PUBLICATION PRESS.-T. C. Martin, Chairman; Albert Spies, H. H. Suplee.

May 1, 1907

By Charles P. Williams

The lead-bearing area of Missouri has been subdivided, geographically, into the Southeastern, the Central, and the Southwestern

"The reduction works of the Boston & Montana Reduction department, near the north end of this dam is one of the reduction plants belonging to the Anaconda Copper Mining Company, the other being at Anaconda. These works employ about 1,100 men and have a capacity of about 3,800 tons of crude ore per day. This plant is now being remodeled to embody results of experiments and investigations which have been made with a view to more economic.al treatment of ores. A brief description of the plant as it will be after the remodelling is as follows:Concentrator Department: Consists of six units or sections, each section treating from 550 to 600 tons of crude ore per day. This department is not being. remodelled at the present time. A concentrating process, however, has been developed and partially installed in the old mill, and an experimental section embodying this concentration process has also been installed at the concentrator at Anaconda."

Jan 1, 1913

Jan 4, 1951

By Vernon Read

Among the technical problems in AEC's Project Plowshare is the necessity of determining the precise effects of nuclear blasts in all kinds of ground formations. This calls for extensive in-situ sampling with full core recovery. In the exploration drilling that often precedes a new test detonation, the AEC and its contractors have applied both novel and established sampling techniques in many new ways, giving improved core recovery and reduced costs in all subsurface sampling and testing. Unique among these new techniques is one that achieved full recovery and virtually undisturbed samples from near-surface layers of unconsolidated boulder-strewn alluvium. This approach involves a combination of oilfield and mining core drilling equipment. Oilfield heavy drill collars, rotary stabilizers and thick, vibration-reducing oil emulsion drilling mud were used in combination with the precise hydraulic feed control, fast (over 300 rpm) bit rotation, light drilling weight, hard rock core barrels and multi-step diamond bits that are common in mining industry diamond drilling.

Jan 8, 1963

By M. C. Udy, P. C. Rosenthal

THE use of minute boron additions to steel has been given considerable attention in recent years. Comparisons made between boron-free and boron-containing heats of otherwise identical analysis have indicated, beyond a doubt, the potent effect of boron for increasing hardenability. The actual hardenability increase has been expressed as a multiplying factor, or in terms of the percentage of other alloying elements boron might replace, The present study presents the results of a systematic survey of. the use of boron as an addition to two types of alloyed steels and as a replacement for various percentages of molybdenum in these steels, Both cast and wrought steels of the two basic compositions were prepared. Molybdenum, because of its scarcity at the time the investigation was started, was selected as the element to be replaced by boron. Attention was also given to the effects of boron on other properties of the steels, particularly their notched-bar toughness, to investigate other advantages or limitations of this element as an alloy addition. EXPERIMENTAL WORK Steels Investigated The two basic compositions used in this survey of boron as a replacement for molybdenum are given in Table I. The cast steels were higher than the wrought steels in silicon content to improve the casting quality. [ ] Each of these base steels, both cast and wrought, was made with molybdenum contents of o, 0.10, 0.20, 0.30, or 0.40 per cent, the total comprising 20 steels. In addition, each of these 20 compositions . was prepared with boron additions in amounts of 0.0015, 0.003, and o,006 per cent as ferroboron; and in amounts of 0.002 and 0.005 per cent as two com¬mercial intensifier alloys, designated alloys A and B. The boron-treated steels totaled 100, and the entire series 120, Test Procedure Each steel was melted as an individual heat in a 50-lb., magnesia-lined induction furnace. Ingot iron scrap or mixtures of ingot iron and steel scrap were used for melting stock. Deoxidation was carried out in the furnace with o.10 per cent aluminum. The aluminum addition was

Jan 1, 1946

By Robert H. Richards

Jan 1, 1897

By E. J. Roberts

Prior to 1916, thickening was an art, and any accurate decision as to what size of machine to install to handle a given tonnage of a specific ore must have been one of those intuitive conclusions, based on both intimate and extensive acquaintance with thick-ners and ore pulps. Then in 1916 "knowledge of acquaintance," became "knowledge about" with the publication of the Coe and Clevenger paper.' The unit operation of thickening had graduated to the status of an engineering science. The fundamental similitude relationships for the two major phases of the operation were defined so clearly that batch tests on models as small as liter cylinders could serve to specify protypes as large as 325 ft in diameter. It is quite apparent from reading the literature that Coe and Clevenger's contribution is not generally appreciated. In so far as the basic engineering relationships are concerned, the only real advance which has occurred in the 30 odd years which have elapsed since the Coe and Clevenger paper is the recognition of the effect of the rakes on the thickening process. Bull and Darby2 noted this in 1926, and the extensive use of the "gluten type" thickener, in which the effect is magni-fied, bears witness to its importance. Comings3 further verified this effect of the rakes. As a matter of fact, a number of papers show an apparent regression from the Coe paper in that the area determinations are made on the basis of a single test from One concentration of solids. Coe and Clevenger amply demonstrated that this is unsafe, since the controlling zone may be one other than that of the feed dilution. Comings3 neatly demonstrated this without apparently realizing it. Of course there have been significant advances in the application of the operation to industry. Open tray thickeners were introduced to save area; balanced tray thickeners, washing thickeners, and multifeed clarifiers were developed with all of their special hydraulic and mechanical problems. Combinations of all kinds have been introduced, such as combination agitators and thickeners, combination flocculators and clarifiers, combination thickeners and filters. With the establishment of the operation on a firm engineering foundation, installation was facilitated and expansion proceeded. There are still problems, of course, functional as well as mechanical. Sometimes the moisture in the underflow obtained in practice is not as low as is expected on the basis of the test data. Sometimes the underflow is so "thick " that its discharge and subsequent handling requires special attention. Island formation plagues some operators. The use of the thickener as a surge basin and blending tank in the cement industry poses unusual problems. Design of rakes and the drive mechanism must be continually im-proved. Corrosion problems must he overcome. Power requirements for raking the settled solids occasionally is the controlling factor as it was in the case of the all American Canal desilting installation. Other similitude relationships and design problems come into the picture when we enter the field of clarification or nonline settlement. We have an energy dissipation problem in introducing the feed and any models must satisfy the Froude model relationships. Autoflocculation requires detention which involves the same similitude laws that we encounter in the compression zone. Approach to an Exact Science The next step beyond having control of the similitude relationships is to understand the why of these relationships right back up the line to first principles. The ultimate might be that, if given the mineralogical composition of the solids and their size distribution together with an analysis of the suspending liquid, we could calculate the entire thickening behavior of the system. Then we could say we had reduced the operation to an exact science. True it might be more trouble getting this basic analytical data than to make our empirical determinations for area and volume, and we would need an ENIAC to calculate the results, but that does not detract from the desirability of such understanding. Considerable work has been done by the chemical engineers with this end in view. Comings,3 Egolf,4 Work,5 Kam-mermeyer,6 Steinour,7 and others have studied the problem. The writer has no final answer to the thickening story but would like to propose a picture of the mechanics of the two phases of thickening which has been found useful in understanding the subject and which leads to some convenient relationship in treating the compression step and arriving at the compression depth.

Jan 1, 1950

By Howard N. Eavenson

WHEN the A.I.M.E. was formed 75 years ago the bituminous coal industry was in its swaddling clothes, although it had been operating for more than a century and coal was being mined in every state now producing it, and its output had long passed that of anthracite. In 18/1, the value of bituminous coal was about seventy per cent of the value of all metals produced and more than one fifth of the value of all products of mines, both metallic and nonmetallic.[1a] While many of the operating mines then shipped by rail, most of the development was along waterways, although the canal era of transportation was nearly at its end. Coal mining is a heavy industry and one of the best measures of its progress is its output throughout the period. Fig. 1 shows this graphically from 1800 to 1945. From 1870 to 1910, the production-which is very nearly the consumption-almost doubled every decade, a most amazing growth. In 1918, in World War I, a peak was reached and a decline began, which ended in 1932. A gradual recovery then started, interrupted in 1938 but culminating in the record output of 1944, when, owing to World War II, a tonnage of 619,576,000 was produced. It is evident that the forces leading to the continuous increase ending in 1918 have spent themselves and that only unusual conditions will require so large a production again. The postwar conditions of World War II will probably

Jan 1, 1947

By H. F. Moore

Jan 1, 1936

By H. F. Moore

Jan 1, 1936