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By A. Hultgren

PAGE Outline of Progress of Knowledge and Theories about Gas Evolution in Steel Ingots, and Its Influence on Crystallization and Segregation 2 Object of Present Investigation 16 theoretical Discussion of Process of Solidification 17 Gas Given Off from Rimming Steel during Solidification 17 Equilibrium Diagram of the Iron-carbon-oxygen Alloys 19 Solidification of Pure Iron-carbon-oxygen Alloys 25 Solidification When Carbon Monoxide Is Given Off at Constant Pressure... 25 Solidification When Gas Evolution Is Suppressed 26 Schematic Application on Solidification of Rimming-steel Ingots 27 Influence of Manganese, Sulphur and Phosphorus 28 Experimental Work 30 Liquid Steel and the Mold Gas 30 Ingots Investigated and Methods Used 33 Ingot Structure 42 Structure of Rim Zone 42 Structure of Core 49 Structures Obtained under Special Conditions of Freezing 50 Distribution of Metalloids 55 Other Observations Made 60 General Discussion of Solidification Process 63 Condition of Liquid Steel before Casting 63 Rimming Period 70 Composition of Rim Zone 93 Freezing after Top Is Closed 96 Slag Inclusions and Ingot Scum 102 Reaction between Gas in Blowholes and Surrounding Solid Steel during Cooling 103 Summary 105 Appendix-Preparation and Etching of Ingot Sections 106 References 107 IN 1934, Jernkontoret (The Swedish Ironmasters' Association) appointed a committee for the study of the structure of rimming-steel ingots and the various phenomena associated with their solidification. The members of the committee, including those who have joined it later, have been: I. Bohm, B. D. Enlund, B. Kalling, M. Tigerschiöld, 1. Wohlfahrt and the authors. The present paper? is a somewhat

Jan 1, 1939

By H. Assadi, S. Reutzel, D. M. Herlach

Intermetallics exhibit unique solidification behaviour due to their chemical longrange order. This includes, for instance, generally slow solidification kinetics, and in some cases, an anomalous partitioning behaviour. In the present work the electromagnetic levitation technique - complemented by theoretical modelling - is used to explore various aspects of this behaviour, as observed in solidification of B2 phase in undercooled melts of the Ni-Al system. Moreover, a phase-field model is developed and used to illustrate the effect of chemical order on the solidification kinetics of a B2 phase in a model system. The phase-field model provides an additional basis for the simulation of solidification microstructures in intermetallic forming systems. Both experimental studies and theoretical work signify the role of chemical order in solidification of intermetallics.

Jan 1, 2006

By Xueyuan Nie, Xuezhi Zhang, Henry Hu, Shen Xinwei, Jimi Tjong, Li Fang

With the demand for weight reduction in vehicles and airplanes, researchers have shown great interested in casting wrought aluminum alloy 7075 because of its potential advantages such as high strength-to-density ratio and stress-reduction capabilities. It is therefore essential to conduct a fundamental investigation on solidification behavior and grain microstructure of alloy 7075. In this study, a commercially-available wrought aluminum alloy 7075 was used to study the solidification behavior of alloy 7075. A thermal analysis was performed based on the cooling curve and its corresponding first and second derivative curves. The nucleation of the primary a-Al phase and eutectic phases were analyzed. The comparison between the microstructures of the wrought and cast 7075 alloys shows that coarse microstructure and porosity are present in the cast alloy. The techniques for grain refinement in casting, such as the addition of the nucleating particles and applied pressure, should be employed to reduce the dendrite arm spacing and the porosity.

Jan 1, 2015

By Renxing Li, Yongyong Gong, Yufeng Cheng, Zhenxing Yin, Xin Cao, Qijie Zhai

"The influence of electric current pulse (ECP) on the solidification structure of SUS430 ferritic stainless steel (FSS) was investigated in the current study. The technology of ECP has been widely used to improve the properties of metals with relatively low cost. The parallel electrodes were inserted into the free melt surface to constitute a current loop. The different influences of three parameters on solidification structure were studied by changing the peak current value, frequency and treating time respectively. The results indicated that the ECP significantly increased the number of equiaxed grains of SUS430 FSS. The as-cast structure without ECP treating was almost wholly columnar, while the number of equiaxed grains of the specimen, which was treated 3min with a peak current of 400kIA, increased to 2698 in the observed surface. To get the best refinement, an optimum range of these three parameters is required and the peak current value plays the most important role.IntroductionFor the lack of nickel resource and the pressure of environment protection, ferritic stainless steel is increasingly adopted to replace the austenite stainless steel because of its low nickel content and good mechanical properties. SUS430 steel is a typical example with excellent performance and relatively low price to replace the application of austenitic stainless steel[1-3]. This type of steel with high thermal conductivity coefficient, low expansion coefficient, good oxidation resistance, excellent stress corrosion resistance and other fantastic characteristics is often used to make components which need to have resistances for atmosphere, water, steam and oxidizing acid corrosion[4]. Since the developing of columnar grains and low toughness at high temperature, its products are easily crinkled and cracked during the subsequent rolling process[5]. The application of ferritic stainless steel is limited by these defects[6-8]."

Jan 1, 2012

By Marcella Gautê Cavalcante Xavier

As ligas livres de chumbo (Lead-free solder alloys) potencialmente utilizáveis em processos de soldagem branda, tais como as ligas à base de Sn, vêm sendo estudadas como alternativas para substituir as ligas do sistema Sn-Pb. Em vista disto, o presente trabalho, aborda tanto a análise das características microestruturais formadas durante a solidificação transitória das ligas eutética Sn-0,2%Ni e hipereutética Sn-0,5%Ni, quanto a determinação das suas respectivas correlações com os parâmetros térmicos de solidificação: velocidade da isoterma eutética (VE) e taxa de resfriamento (?E). Para tanto, as ligas foram solidificadas unidirecionalmente no sentido vertical ascendente e em regime transiente, e caracterizadas por técnicas de microscopias ótica e eletrônica de varredura. Na liga hipereutética Sn-0,5%Ni, o aumento da quantidade de Ni na liga influenciou tanto o comportamento térmico quanto o espaçamento celular (λC), proporcionando maiores valores de ?E, porém, λC mais grosseiros.O intermetálico NiSn4 formou-se na região eutética de ambas as ligas, enquanto que na liga Sn-0,5%Ni, as fases primárias identificadas por EDS-MEV foram NiSn4 e Ni3Sn4. A transição morfológica celular/dendrítica(?E> 1,2ºC/s) ocorreu apenas para a liga eutética, enquanto que as células regulares da liga hipereutética deram origem as células do tipo placas(?E> 1,4ºC/s).

Oct 30, 2017

By Cínthia Toshimi Ogata

Processos de fundição de ligas de alumínio com altos teores de Mg são um desafio da indústria, uma vez que diferentes taxas de resfriamento ocorrem em geometrias diversas. Este trabalho tem como objetivo caracterizar a liga de alumínio AA5052 com variações em teores de Mg por meio de experimentos de solidificação direcional transitória, e compreender seus efeitos com relação a evolução de parâmetros térmicos, microestruturais, e propriedade mecânica. As leis experimentais de evolução do espaçamento dendrítico primário (?1) com relação a taxa de resfriamento resultam em: ?_1=640 ?T ?_L?^(-1/4) para a liga 5052 com 2,4%Mg e ?_1=300 ?T ?_L?^(-1/4) para a liga com 3,2%Mg. As leis de crescimento de espaçamento dendrítico secundário (?2) com relação a velocidade de solidificação resultaram em: ?_2=27 ?V_L?^(-1,1) para a liga 5052 com 2,4%Mg e ?_2=15 ?V_L?^(-1,1) para as ligas com 2,6%Mg e 3,2%Mg. Maiores teores de Mg na liga AA5052 proporcionaram uma expressiva redução no valor de ?2 para uma determinada VL. A evolução da dureza mostrou-se diretamente relacionada ao tamanho e a distribuição dos intermetálicos presentes, sendo ?2 o fator predominante neste controle.

Oct 30, 2017

By Jr. Pitts

Elevation of surface charge density on colloidal particles in the presence of a high potential electrostatic field is demonstrated as a viable technique for preventing the accumulation of solids in solvent extraction circuits. The effect of the technique is manifest by relative turbidity measurements between pregnant leach solution and raffinate, by changes in the character of the sludge accumulations, by alteration of the zeta potential of particulates, and by a general reduction in the mass of solids.

Jan 1, 1992

By J Sarvinis

The design and operational aspects of fluidised solids transfer-cooling devices will be discussed in this presentation. The devices include air slides and fluoseals (also called seal pots, loop seals, etc), which are widely used in metallurgical plants and other processing plants. Cooling can be achieved while solids are transported in the solids transfer devices. The units combining solids transfer and cooling provide compact and clean plant layouts and also reduce capital and operational costs. Fluidised devices provide excellent gas-to-solids and gas/solids-to-surface heat transfer rates, hence high cooling efficiency. Fluidising gas, such as air, nitrogen or other gases, can be used as direct cooling mediums. Coolants such as water, steam and other liquid or gas cooling fluids can be used as indirect cooling mediums via tube coils immersed in the fluidised solids. The fluidised transport devices share some common features with fluidised bed equipment. The air slide is similar to a linear fluidised bed while the fluoseal is similar to a circular fluidised bed. Therefore fluidised bed design techniques are applicable to the design of the air slides and fluoseals. The heat and mass balance and temperature profiles of the devices concerned will be discussed in the presentation. The design criteria and operational philosophies of the critical components such as tuyeres and air spargers will also be discussed.

Jan 1, 2006

By F. S. White, E. L. Kinsella

THE solids fluidization process brought out by the Standard Oil Development Co. in the early forties for catalytic cracking of petroleum enabled rapid transfer of large quantities of heat from gases to solids under closely controlled temperature conditions. As the technique developed, it was natural that applications for the process outside the petroleum industry would be sought. The calcination of limestone to ' quicklime requires the transfer of a large quantity of heat at high and closely controlled temperatures. For these reasons, this possible application was one of the first to be investigated. Laboratory work conducted by the Dorr Co. indicated that lime produced by solids fluidization would be of exceptional quality. Calculation of theoretical heat balances showed that savings in fuel could be expected. Accordingly, a pilot plant of 10 tons per day capacity was erected by the New England Lime Co. at Adams, Mass., to substantiate the process. Operation of the pilot plant, previously described,1 showed that excellent lime could be produced with a saving in fuel. The work also indicated the necessity of preparing feed to remove the finer fractions if dust losses were to be held to a tolerable level. A single-stage fluidized solids drier-stripper was developed to accomplish this sizing.2 Subsequently a commercial lime reactor was erected at Adams, beginning operation in June 1949, followed by air sizer facilities completed in November 1951. This paper will describe these two applications of solids fluidization. The raw material for preparation of lime by the fluidizing process is a high calcium crystalline lime stone having the approximate chemical composition shown in Table I. The stone is first prepared by crushing and grinding in conventional equipment to pass a 6-mesh sieve. After crushing, the material is sent to the FluoDry unit for drying and dedusting. Fluidized Drying and Sizing As shown in Fig. 1, the FluoDry unit consists of a 1/4-in. cylindrical steel shell, 9-ft ID by 22-ft 6-in. overall height. Attached horizontally at the bottom is a 6-ft diam combustion chamber, approximately 7 ft 6 in. long. A refractory constriction dome, consisting of first-quality fire brick shapes, partitions the inside into two sections. The lower section is called the windbox and the upper the bed compartment. The vertical wall of the shell is lined with 6-in. first-quality rotary kiln blocks. In the bottom of the windbox a hoppered section is formed with castable refractory to permit the windbox to be readily cleaned via a 6-in. screw conveyor. The combustion chamber is similarly lined with refractory shapes. On the 6-in. diam section, 4 1/2 in. of insulating brick, HW-26, are used. The inner combustion chamber is lined with 4 1/2-in. Korundal brick to withstand the high flame temperatures encountered. An 8-in. steel feed pipe, entering vertically through the top and fitted with an air-operated cone valve,

Jan 1, 1952

By Jan J. Cilliers, Nicolas Barbian, Esther Ventura-Medina

"Mineral froth flotation is one of the most widely used processes to separate particles of valuable mineral from its associated gangue. It involves the selective separation of the hydrophobic particles from the slurry into the froth. The hydrophobic particles attach to the air bubbles and rise up to the froth phase on top of the slurry. The valuable mineral is collected when the froth overflows the cell wall. The separation performance of the process can be linked to the amount of solids and valuable material loaded on the bubble shells. In addition, it is well known that in most mineral systems, the presence of solids can enhance the stability of the froths. How the solids get to be distributed and what proportion is actually attached and stabilising the bubbles is not well known.This study aims to establish the relationship between operational variables, solids loading on bubbles and flotation performance. For this purpose, a series of industrial experiments to sample the solids in the bubble films under different operational conditions were carried out in two copper concentrators under steady state conditions. Samples of the lamellae were taken by touching the top surface of the bubbles with a glass slide. The amount of solids and liquid per unit area in the bubble lamellae can subsequently be estimated gravimetrically and by image analysis. The grade of the attached particles was also measured by adequate sampling. This gives an indication of the maximum grade that could be achieved from the process under the operating conditions."

Jan 1, 2003

By C. Matthews, A. Vo

"Australia is one of the world’s leading exporters of bulk commodities and the extensive use of sampling equipment is key to the successful management of each mining operation. At the process plant, without a full understanding of the feed, product and tails, it is impossible to fully optimise the performance of the plant, such that the metallurgical balance is often open to error. At the port, a statistically correct, bias free and compliant sampling system is crucial to ensuring exported minerals are reflective of their true value and to avoid penalties. Over the last decade, as a result of the iron ore boom, there has been high demand for reliable, representative and standard compliant solids sample systems in Australia. This paper reviews several solids sampling applications at Australian mine sites, the challenges and experience gained and how the implementation of reliable representative sampling systems has provided better understanding of plant process performance, improved plant control and overall benefits to the operations.INTRODUCTION Mining is the primary contributor to the Australian economy with Australia ranking in the top 4 in economic resources for 21 primary industrial minerals in 2016 (Britt, et al., 2017). Australia is one of the world leaders in the export of the majority of its commodities including gold, copper and iron ore (Britt, et al., 2017). Therefore, a suitable and standard compliant sampling system is essential for evaluating plant performance and content verification. At the mine and at the port, the larger iron ore miners in Australia have developed stockpile models to predict the grade of their ore down to individual blocks of the stockpile. This allows the miner to create the right blend of material for sale to their customers and ensures they are not underselling their product or at risk of penalties for impurities or low grade. As an example, the average difference between the benchmark 62% Fe and low grade 58% Fe fines at the time of this report averaged US $30/tonne according to the Metal Bulletin Iron Ore Index. At a shipload of 180kt this would be a variation of US $5.4M. Whilst this is an extreme example, it highlights the economic importance of producing the correct grade product and a recognised representative sample of said product."

Jan 1, 2019

By C. Matthews, A. Vo

Australia is one of the world’s leading exporters of bulk commodities and the extensive use of sampling equipment is key to the successful management of each mining operation. At the process plant, without a full understanding of the feed, product and tails, it is impossible to fully optimise the performance of the plant, such that the metallurgical balance is often open to error. At the port, a statistically correct, bias free and compliant sampling system is crucial to ensuring exported minerals are reflective of their true value and to avoid penalties. Over the last decade, as a result of the iron ore boom, there has been high demand for reliable, representative and standard compliant solids sample systems in Australia. This paper reviews several solids sampling applications at Australian mine sites, the challenges and experience gained and how the implementation of reliable representative sampling systems has provided better understanding of plant process performance, improved plant control and overall benefits to the operations. INTRODUCTION Mining is the primary contributor to the Australian economy with Australia ranking in the top 4 in economic resources for 21 primary industrial minerals in 2016 (Britt, et al., 2017). Australia is one of the world leaders in the export of the majority of its commodities including gold, copper and iron ore (Britt, et al., 2017). Therefore, a suitable and standard compliant sampling system is essential for evaluating plant performance and content verification. At the mine and at the port, the larger iron ore miners in Australia have developed stockpile models to predict the grade of their ore down to individual blocks of the stockpile. This allows the miner to create the right blend of material for sale to their customers and ensures they are not underselling their product or at risk of penalties for impurities or low grade. As an example, the average difference between the benchmark 62% Fe and low grade 58% Fe fines at the time of this report averaged US $20/tonne according to the Metal Bulletin Iron Ore Index (Fastmarkets MB, 2019). At a shipload of 180kt this would be a variation of US $3.6M. Whilst this is an extreme example, it highlights the economic importance of producing the correct grade product and a recognised representative sample of said product.

Jan 1, 2019

By Benjamin K. Pocock

When considering alternative equipment choices in mill or process flowsheets, it is important to determine both capital and operating costs of such equipment as well as other possible savings related to downstream operations. This paper presents a few case studies and shows cursory guidelines for the selection of equipment for new installations or in the retrofitting of existing plants. Based upon recent plant experience, suggestions are given to improve the operation of clarifiers, thickeners and vacuum filters.

Jan 1, 1986

By C Simpson

In 2011 the forecasted world demand for iron ore continues to grow, and during this time Australia is looked upon as a reliable supplier of high quality ore. The expansion of the current Australian mines is unlikely to meet the forecast demand. New mines are therefore being actively explored for and when discovered, are quickly being developed into mines in order to meet the world’s hunger for steel.The Solomon Project area is a large new iron ore discovery, located in the central Hamersley Ranges of the Pilbara province in Western Australia. The first Fortescue exploration drill holes commenced on the project in 2007 and to date three billion tonnes (Bt) of iron ore have been defi ned within the project area. Fortescue is fast-tracking the development of the ‘Solomon Stage 1’ project, with rail and mine construction commencing during 2011, and ore to be railed to Fortescue’s existing shipping operations at Port Hedland commencing in 2012. At a designed production rate of 60 Mt/a, the Solomon operation will be one of the biggest production centres of iron ore in the Pilbara.Deposit types include the three dominant mineralisation styles of the Pilbara province, being bedded iron deposits (BID), Channel iron deposits (CID) and detrital iron deposits (DID). All these mineralisation styles are present in large concentrations within the Solomon project area, and when mined will produce two product streams. These are a single product of CID, and a combined product from a blend of BID and DID material.This paper defines the geological characteristics of the Solomon iron deposits as recognised through the exploration and development of this vast resource over the three years since exploration commenced on the project.

Jul 11, 2011

By E. G. Noble

The effects of HBr concentration and temperature on the solubility and hydration state of AlBr3,' CoBr2, PbBr2, MnBr2, KBr, and NaBr were investigated by the Bureau of Mines. Saturated aqueous solutions of the AI, Pb, K, and Na bromides were sparged with HBr gas at 20°, 40°, and 60° C, and saturated solutions of Co and Mn bromides were sparged at 20° C. Increased HBr concentration caused decreased salt solubility because of the common ion effect for all the investigated bromides except PbBr2. Aqueous solubilities at 20° C were, in percent, 51.7 for AlBr3, 53.2 for CoBr2, 1.1 for PbBr2, 59.6 for MnBr2' 39.5 for KBr, and 47.4 for NaBr. At 60° C, the solubilities were, in percent, 53.3 for AlBr3, 2.2 for PbBr2' 46.0 for KBr, and 53.8 for NaBr. Solubilities in solutions sparged to HBr saturation at 20° C were, in percent, 0.5 for AlBr3, 42.0 for CoBr2, 32.2 for PbBr2, 21.0 for MnBr2, 0.6 for KBr, and 0.3 for NaBr. At 60° C, the solubilities at HBr saturation were, in percent, 1.8 for AlBr3, 41.4 for PbBr2, 1.3 for KBr, and 0.4 for NaBr. CoBr2 precipitated out to a minimum solubility of 27.2 pct at 28.7-pct-HBr concentration. Further increases in HBr concentration increased CoBr2 solubility because of the formation of bromide complexes. PbBr2 in-creased in solubility as HBr concentration increased.

Jan 1, 1988

By E. G. Noble

The effects of hydrogen chloride (HCI) concentration and temperature on the solubility and hydration state of the alkali chlorides LiCI, NaCI, and KCI and the alkaline-earth chlorides, MgCI2, and CaCl2 were investigated by the Bureau of Mines. Saturated aqueous solutions of the chlorides were sparged with HCI gas at temperatures of 20°, 40°, and 60° C. Increased HCI concentration caused decreased salt solubility be-cause of the common ion effect. Aqueous solubilities for the chlorides of Ca, Li, Mg, K, and Na ranged from 42.6, 45.2, 35.2, 25.5, and 26.1 pct, respectively, at 20° C to 56.9, 49.4, 37.6, 31.0, and 27.0 pct, re-spectively, at 60° C. In solutions sparged to HCI saturation, solubili-ties for these chlorides ranged from 22.4, 26.5, 3.0, 1.3, and 0.05 pct, respectively, at 20° C to 53.2, 48.8, 28.3, 2.6, and 0.8 pct, respec-tively, at 60° C. The solubilities of LiCI and CaCl2 in HCI solution were high because HCI solubility is low in these solutions. The chlo-ride salts of Ca, Li, and Mg formed hydrates, which depended on tempera-ture and HCI concentration. Monohydrates for LiCI, tetrahydrates and hexahydrates for MgCI2, and dihydrates, tetrahydrates, and hexahydrates for CaCl2 were obtained.

Jan 1, 1985

By A. W. Ashbrook

From both economic and environmental aspects, the loss of organic materials from a solvent extraction process is of major concern. A decade ago perhaps the only consideration given to solvent loss was economic in nature. Today, the environmental -.and hygiene - impacts have to be seriously considered. In this section we shall deal essentially with the processing and economic aspects of solvent loss; the environmental aspects are discussed in a later section.

Jan 1, 1978

By E. Morrice

Solubility of yttrium oxide (Y203) in fluoride melts was experimentally measured in the temperature range of 998 to 1273 K and, YF3 composition in LiF.YF3 melts varying from 20 to 50 mole pct using a graphite crucible in an argon atmosphere. Solubility of oxide in the melt was found to increase with increasing temperature and YF3 composition in the melt. An expression for in XY2O3 as a function of temperature for several melts was deduced. The calculated activity coefficients of Y2O3 in the melts exhibited a negative deviation from Raoult's law.

Jan 1, 1989

By Carl F. Floe, Michael B. Bever

THE possibility that carbon may be soluble in copper to a limited extent has been recognized for over a century. The quantitative investigation of this problem, however, requires more sensitive techniques than have formerly been available. Three recent developments have made possible more accurate determinations: the vacuum-fusion method of analysis, the production of copper of high purity and the availability of high-purity refractories, particularly graphite. In addition to its obvious theoretical interest, the problem of carbon solubility in copper is of practical importance. In the production of copper and of high-copper alloys, carbonaceous covers are frequently used. If even minute amounts of carbon are dissolved, insoluble carbon oxide gases will be formed when such metals are poured under oxidizing conditions. A mechanism of this kind could well be one of the principal causes of gas porosity in casting copper-base products. REVIEW OF LITERATURE In 1823 Vivian1 raised the question as to whether copper by overpoling becomes "combined with a minute portion of carbon." Karsten2 asserted, in 1832, that carbon reduces the high-temperature strength of pure copper, so that when the carbon content has reached 0.2 per cent the metal will be brittle at a dark red heat. According to Karsten, carbon contents of o.05 per cent make it difficult to hot-work copper. He also reported that the specific gravity of copper is 8.8969 and that it increases to 8.92 58 if the copper is cemented with carbon and then melted. He emphasized the difficulty of determining analytically the small amounts of carbon present in copper. The metal was removed by wet methods and the residue considered as carbon. At Percy's request, Dick,3 in 1856, carried out various working tests on copper that had been in prolonged contact with carbon, and found that the working properties of the metal had not been affected. He also attempted to determine the presence of carbon analytically. In one experiment the copper was dissolved and the residue was fused with litharge, and in another essentially a combustion analysis was made on a copper sample. In a final experiment, a sample was dissolved and the residue subsequently subjected to a combustion analysis. Indications of as much as o.005 per cent carbon were found, but Dick considered his work inconclusive largely because of the possible interference of sulphur. Percy4 concluded, from Dick's experiments and from some experimental work of his own, that the solubility of carbon in copper had not been established with

Jan 1, 1945

By John R. Anderson, Michael B. Bever

CARBON may affect the alloys of copper in several ways. Provided an alloying element does not oxidize preferentially, even minute quantities of carbon dissolved in liquid alloys of high copper content will form insoluble carbon oxide gases under oxidizing conditions. Gas porosity in castings of high-copper alloys can originate in this way. In certain alloys of low copper content carbon may have considerable solubility and may be an effective deoxidizer. In these alloys carbon will tend to suppress porosity. Carbon that is dissolved in the molten alloy is likely to be retained in the solidified metal. The effects of carbon on the physical properties of the metal are determined by the form in which it is present. Depending on the alloying elements and also on the cooling rate, carbon may precipitate as graphite, may form a carbide or may remain in solid solution on cooling. As solid copper does not dissolve a measurable amount of carbon, a carbon-bearing solid solution can occur only if the copper is alloyed with a large excess of an element that forms such a solution. The effect of graphite or of carbides on the properties of an alloy will depend on the size and distribution of the precipitated particles. As Hensel pointed out in discussion,1 the formation of an alloy carbide may interfere with the age-hardening properties of a copper alloy. One would also expect that the presence of carbides or of graphite will under certain conditions promote corrosion or high-temperature failure in nonferrous alloys. Since carbon has an effect on the soundness of castings and affects the structure and behavior of solid copper alloys, its solubility in the liquid alloys is of practical importance. The isothermal change of carbon solubility with alloy composition is of interest from a theoretical standpoint. The binary alloys of copper with manganese and with nickel are used industrially and serve as a base for more complex alloys. The solubility of carbon in each of these metals is known, but its solubility in their alloys has not been determined. EARLIER DATA The solubility of carbon in molten pure copper is about 0.0001 pct at 1100 °C and 0.0004 pct at 1475°C.1 Various authors2-6 have published data on the solubility of carbon in molten manganese. There is agreement on a value of about 6.7 pct in the temperature range 1217° to 1245°C. This solubility value corresponds to the formula Mn3C. It increases very little with increasing temperature. Corson7 states that carbon is soluble in copper-manganese alloys and that the

Jan 1, 1947