Production Of Cast Iron Research Articles

The Comparison of Selected Methods of Cast Iron Spheroidization in Industrial Conditions

The Comparison of Selected Methods of Cast Iron Spheroidization in Industrial Conditions Production of spheroidal graphite cast iron is today quite mastered technology. There are many methods achieving the nodular graphite morphology. Each of these methods have specific characteristics and requirements to technical support, properties and the type of applied modifier. Selection of the spheroidization method is dependent on foundry disposition, production character, economic balance, quality requirements, etc. In case of centrifugally casting the core, which fills body and neck of the roll, is created by ductile iron. Considering the sophisticated production of centrifugally cast rolls for hot rolling mills it is necessary to ensure a high reproducibility and reliability of ductile cast iron production quality in the bulk range of 9-18 t per tapping. These conditions are in the Roll Foundry in Vítkovicke Slevarny, spol. s r.o. provided and verified mastered overpour method and the newly injection of cored wire in the melt.

Modern Cored Wire Injection 2PE-9 Method in the Production of Ductile Iron

The results of studies on the use of modern two cored wires injection method for production of nodular graphite cast iron with use of unique implementation of drum ladle as a treatment/ transport and casting ladle instead vertical treatment ladle was described. The injection of length of O 9mm wires, cored: in FeSi + Mg nodulariser mixture and inoculant master alloy is a treatment method which can be used to produce iron melted in coreless induction furnace. This paper describes the results of using this method for possibility production of ductile iron under specific industrial conditions. In this case was taken ductile iron with material designation: EN-GJS-45010 Grade according PN-EN 1563:2000. Microstructure of 28 trials was controlled on internally used sample which has been correlated with standard sample before. The paper presents typical metallic matrix and graphite characteristic. Additionally, mechanical properties were checked in one experiment. Because of further possibility treatment temperature reduction only the rough magnesium recovery and cost of this new method are given.

Adaptation of Acidithiobacillus bacteria to metallurgical wastes and its potential environmental risks

Metallurgical wastes--oxygen converter sludge, dust from cast iron production, lead matte, and slag from recycling of used lead batteries--were treated with Acidithiobacillus bacteria. Bacterial activity and adaptability on waste and some waste mixtures were investigated. Acidithiobacillus bacteria may easily attack oxygen converter sludge, lead matte and slag and affect the mobility of metals. Cast iron dust is not a suitable substrate for applied bacteria due to the absence of reduced sulfur and reduced iron in its mineralogical composition. Nevertheless, the pure culture was able to adapt to the mixture of this waste with slag. Disposal of these metallurgical wastes deserves special attention due to potential attack by microorganisms and consequent pH changes. According to subsequent release of hazardous substances to the environment, this phenomenon can lead to evident environmental risks.

Research of Properties and Microstructure on High-Strength Casting of Turbo-Charger

Combining with productive practice, production of intermediate castings in high-strength turbochargers under the condition of intermediate frequency furnaces is analysed in this paper. By adopting measures of compound inoculation and increasing Sulfur, 95% type A graphite and high-strength intermediate castings whose tensile strength is 300 MPa are acquired. Furthermore, moderate amounts of S and Mn as well as CE values are determined according to test results. As for thin-wall gray cast iron with high strength and complicate structure, whenwSis low andwCis high, castings with good graphite form can be produced. But it is not stable and the strength is low. Adding inoculants like Calballoy and Si-Ca-Ba can significantly improve the graphite form on the edge of thin-walls. WhenwCis stabilized at about 4.1, stable and continuous production of high strength gray cast iron with good graphite form can be guaranteed by adding sulfur and controlling the amount of Mn. The proportion of A type graphite and that of pearlite are both more than 90%.When high-strength gray cast iron is produced in intermediate frequency furnaces,wSshould be controlled between 0.1% and 0.12% andwMnshould be controlled between 0.5% and 0.55%.

A Model for FeSiMg Alloy Production by Reduction Technique

Ferrosilicon magnesium is basic foundry alloys used for the production of ductile cast iron. Magnesium content plays an important role in the produced alloy grades from dolomite ore. The focus of the present work is to simulate mathematical model to predict magnesium content in the ferrosilicon magnesium, which produced by silicothermic reduction of calcined dolomite. The basic assumptions of this model are: constant low viscosity of molten charge, the reaction is irreversible of second order and the reaction is isothermal. The reaction is based on the following equation: 2MgO+2Si →Mg2Si+SiO2 The results of previous work was found to be in a good coincidence with the predicted values by the model [Mg]=(MgO0)[Si0][eKt[(MgO0)-[Si0]]-1]/ (MgO0)[eKt[(MgO0)-[Si0]]-[Si0]] where [Mg] is the concentration of magnesium metal in ferrosilicon magnesium alloy in mol/L. [Si0] and (MgO0) are the initial concentration of silicon and magnesium oxide in charge in mol/L, while t is time in second, K is the reaction rate constant ( 3.26588x10-7 L Sec-1 mol-1). The predicted values are greater than the experimental values; this may be attributed to the use of concentration instead of the activity. The predicted values of magnesium content in ferrosilicon magnesium alloy are in a good agreement with the experimental results obtained in previous work at low viscosity.

The Role of Alloy Design in Semi-Solid Casting of Ductile Iron Processed by Inclined Cooling Plate

The inclined Cooling Plate process can be considered as a reliable method for the production of semi-solid ductile cast iron. By utilizing aforesaid method, the main limitation of common semi-solid methods, i.e. Mg fading, will be eliminated. The present research is intended that the importance of alloying design through the inclined cooling plate method and its profound effect on obtaining the optimum solidification range for thixo-forming process have been illustrated. The optimization of solidification range for thixo-forming process has been gained by the simulation in both equilibrium and non-equilibrium conditions. Afterwards the alloy selection has been performed amongst several alloying composition with a view to their effect on the thixo-forming process and austempering.

Development of a New Route for Fe-C-Al Cast Iron Production

Fe-C-Al alloy system spheroidal graphite cast iron has enormous benefits such as higher strength and hardness, better wear and oxidation resistance etc. at room temperature as well as high temperature. However, its application is not still being popularized due to the production difficulties. In this investigation, a special type of design was developed to perform the magnesium (Mg) treatment in the melt. The raw materials were melted in an induction furnace and later liquid metal was treated using pure Mg foil for spherodization in special crucible. The microstructural study was performed using scanning electron microscope (SEM). The chemical analysis shows a great breakthrough in Mg recovery of Fe-C-Al alloy system spheroidal graphite cast iron. It is also shown that the mechanical properties such as hardness, tensile strength and ductility are comparable to the previous research work.

On Line Oxygen Activity Measurements to Determine Optimal Graphite form During Compacted Graphite Iron Production

Lately, the present authors published a study where oxygen activities were measured using a commercial sensor, which became recently available. In ductile cast iron melts with ferritic and pearlitic structure, optimal properties occur for a well-defined oxygen activity. Castings poured in these circumstances present maximal nodularity, elongation and ferrite content combined with lowest hardness. Additionally, the first results for compacted graphite cast iron were published. The present contribution examines in much more detail the effect of sulfur and oxygen activity on several phenomena important during production of compacted graphite cast iron. These phenomena are the limit for which mechanical properties as defined in ISO16112 are met, the transition from compacted graphite to lamellar graphite and the point at which 20 percent nodularity occurs.

Shopfront Design and Construction: The Use of Iron

The application of iron to shopfront design became increasingly popular through the course of the nineteenth century. This fashion was strongly influenced by technological advancements that allowed the mass production of an enormous range and variety of affordable cast iron products. This article gives a brief introduction to the development of the iron industry in Scotland and explores in more detail how the use of iron affected shopfront design. 6.1 Illustration of casting examples from Walter MacFarlane & Company's 6th Edition Catalogue, 1882. The advent of cast iron structural and decorative architectural components made the decoration of buildings more affordable; this catalogue extract illustrates the impact that decorative architectural cast ironwork could have on the façade of a commercial building. (Crown Copyright)

Theory of Graphite Nucleation in Lamellar Graphite Cast Iron

The precise knowledge of the fundamentals of nucleation is the key to a reliable production process for the fabrication of high quality cast iron products. In most foundries the production process is optimized based on practical experience and not on precise theoretical knowledge. Our work focuses on the research of graphite nucleation in lamellar cast iron. The results of the microscopical investigations are showing for the first time centres of graphite lamella. They are present in the middle of the MnS-particles. The nucleation of graphite on MnS particles was confirmed by microstructure simulations. Studies on the influence of Mn and S on the grain microstructure show that the contents of both elements play an important role. By treating the melt with small contents of Mg, MnSMg particles could also be observed in the matrix as well as in the graphite centres.

Reciclaje de escoria granulada de fundición (EGF) como sustitución de parte del cemento en hormigón

El reciclaje de residuos sólidos industriales se ha vuelto una práctica indispensable en la preservación de los recursos naturales, en la minimización de los costos y en la reducción del impacto ambiental. La utilización de materiales alternativos en la industria de la construcción civil es una práctica económicamente atractiva y ambientalmente correcta. Siendo así, el empleo de escorias como materia prima en carreteras, hormigón y cemento ya es una práctica corriente, en la cual, el destino más noble de estos materiales reciclables depende de la existencia de características adecuadas al uso propuesto. La escoria granulada de fundición (EGF) es un residuo generado en el proceso de fusión de chatarras de hierro fundido en horno cubilote. Estudios anteriores apuntaron que esta escoria, cuando es finamente molida, presenta buenas propiedades piroclásticas (de tipo pozzolana). Además, su estructura amorfa, resultante del proceso de generación a través del enfriamiento brusco y la composición química adecuada, permiten una aplicación más noble de este residuo, como sustituto del cemento. Este trabajo tiene como objetivo estudiar el desempeño de hormigones con la utilización de escoria granulada de fundición como sustitución de parte del cemento, a través de la evaluación de sus propiedades mecánicas. Para ello fueron moldeados cuerpos de prueba de hormigón con diferentes combinaciones de tenores de sustitución de cemento por escoria granulada de fundición (10%, 30% y 50%), en volumen, y relaciones agua/aglomerante (0,40; 0,55 0,70), a ser comparadas con el hormigón de referencia (sin EGF). Para cada edad de hormigón (7, 28 y 91 días) se realizaron ensayos mecánicos, tales como la resistencia a la compresión uniaxial, resistencia a la tracción por compresión diametral y resistencia a la tracción en la flexión. Resultados muestran que la escoria granulada de fundición presenta adecuado desempeño (propiedades mecánicas) en relación a la aplicación propuesta.

The Comprehensive Utilization of EAF Dust and Pickling Sludge of Stainless Steel Works

The EAF Dusts and pickling sludges generated in the stainless steel production contain a lot of valuable metals such as iron, nickel, chromium and manganese. Their compositions are similar to those of laterite nickel ore, and sometimes even better than that at the contents of nickel and chromium. But it is regret that these valuable resources were random piled up or landed fill disposal. In this paper, the typical EAF dusts and pickling sludges and reductant coke powder were mixed in appropriate ratio, and then smelted in a medium frequency induction furnace. In the smelting process, the lime powder and fluorite was added to fluxing, and the ferrosilicon powder was added to strengthen the reduction. The product nickel-chromium-iron can be used as the raw material for stainless steel or cast iron production. The technology has good social and economic benefits.

Complex modifiers produced by rolling of powder mixtures for iron–carbon steels

The paper examines the rolling of powder modifying mixtures to produce complex composite modifiers (CCMs). The mixtures contain hard-to-mold components constituting the major fraction (up to 70 wt.%) of complex modifiers. It is of primary importance to produce sufficiently strong and moldable billets in the form of modifier strips. The rolling parameters and the ratio of hard-to-mold and plastic materials in CCMs are examined to maximally increase the content of the main modifying components and thus to decrease the amount of CCM introduced into liquid metal to modify cast iron. Production tests show that rolled CCMs show good recovery, have a stable effect, and permit the production of high-strength cast iron without chill.

Odor frequency and odor annoyance. Part I: assessment of frequency, intensity and hedonic tone of environmental odors in the field

Odors can be evaluated as being pleasant or unpleasant (hedonic tone), but this differentiation was not incorporated into environmental odor regulation. In order to study the hedonic-induced modification of dose-response associations for community odor annoyance a pertinent field study was conducted. This paper covers the first step, namely the development and validation of a standardized human observation strategy for the direct quantification of the frequency, intensity, and hedonic tone of environmental odors in the field. Grids with equidistant observation points were located around six industrial odor sources, two with pleasant (sweets, rusk bakery), two with neutral (textile production, seed oil production), and two with unpleasant odor emissions (fat refinery, cast iron production). These points were visited by trained observers, screened for normal olfaction and reliable performance, in a systematic fashion for an observation time of 10 min duration. Exposure-related information from the observers in terms of frequency, intensity (six-point scale) and hedonic tone (nine-point scale) were compared to that of 1,456 residents using the same rating scales. Residents evaluated the industrial odors more intense and more unpleasant than the panelists. Furthermore, for the residents only negative relations between odor intensity and hedonic tone were found while for the observer pleasant odor became more pleasant with increasing intensity. Instead of three classes of industrial odors, namely pleasant, neutral and unpleasant, the responses allowed only for two odor classes, namely pleasant and not pleasant, the latter also covering the neutral category. The developed methodology has been shown to yield valid information about odor exposure in the field. With regard to different application settings the discrepancies between external observers and affected residents are discussed in terms of different information processing strategies, namely stimulus-based (bottom-up) for the panel and memory-based and, thus, subject to cognitive bias for the residents (top-down).

Influence of duplex melting process on melt quality and solidification of grey cast iron

The quality of molten iron produced by two melting processes, the medium frequency induction furnace melting process and the shortcut duplex melting process with blast and medium frequency induction furnaces, has been studied comparatively. The shortcut melting process contributes to a higher undercooling tendency of base iron, and the extent of this tendency depends on other processing parameters such as ratio of charges, fluctuation in composition, superheating temperature and holding time, etc. When the shortcut melting process is used in the production of grey cast iron, there are no essential differences, with subsequent proper inoculation, in the microstructure and mechanical properties of castings compared with the conventional medium frequency induction melting process. Inoculation is a very effective method to alleviate and/or eliminate the negative effect when the shortcut melting process is used.

Odor frequency and odor annoyance Part II: dose–response associations and their modification by hedonic tone

Risk-assessment for environmental odors and the development of an appropriate guideline for protection against undue odor annoyance have long been hampered by the difficulties of assessing odor exposure and community annoyance responses. In recent years, however, dose-response associations between frequency of odor events and odor annoyance level in the affected population were established. However, the influence of hedonic tone (pleasantness-unpleasantness) and perceived odor strength (intensity) on the degree of odor annoyance have long been neglected in such studies and accompanying guidelines. In order to close this gap a pertinent field study was conducted in the vicinity of six odor emitting plants, two with pleasant (sweets production, rusk bakery), with neutral (textile production, seed oil production), and with presumably unpleasant odor emissions (fat refinery, cast iron production). A standardized sensory method was developed (described in Part I in the accompanying paper) to quantify intensity and hedonic tone within the assessment of odor exposure by systematic field inspection with trained observers. Additionally, exposure-information, the degree of annoyance, and the frequency of general health complaints and irritation symptoms were collected from the exposed residents through direct interviews. Multiple logistic regression analysis was used to establish dose-response associations between odor frequency, intensity and hedonic tone as independent variables and annoyance or symptom reporting as the dependent variable. It is shown that exposure-annoyance as well as exposure-symptom associations are strongly influenced by odor hedonic. Whereas pleasant odors induced little to no annoyance, both neutral and unpleasant ones did. Additional inclusion of odor intensity did not improve the prediction of odor annoyance. Frequency of reported symptoms was found to be exclusively mediated by annoyance. The results are discussed in terms of environmental stress emphasizing the WHO-definition of health. Based on these findings the existing German guideline against undue odor annoyance was modified.

Use of processed open-hearth dump slag for production of cast iron

Use of processed open-hearth dump slag for production of cast iron

EMPREGO DE AREIA USADA DE FUNDIÇÃO EM COBERTURAS INTERMEDIÁRIA E FINAL DE ATERROS SANITÁRIOS DE RSU

Nowadays final disposal systems of urban solid waste must be operated in a way that optimizes the biochemical degradation processes inside those systems. As a result of that, and because it is directly linked to landfill waste, leachate treatment must be seen as part of the final deposition system of domestic solid waste. Urban solid waste from the city of Portao, RS, has been used in the study. Foundry used sand (green sand from molding process of the cast iron production) was used as intermediate covering layer of the landfill. Other two materials were also tested: local soil of the city of Portao, and construction waste, in order to evaluate which one would have better performance as intermediate and final layer cover. The results have indicated that construction waste is the most appropriate to be used as intermediate layer. On the other hand, soil and used sand have presented more potential to be used as final covering layer.

Optimization of an Automatic Blast Furnace through Integrated Simulation Modeling

The objective of this study was to develop an integrated simulation model of an automatic blast furnace in a full-scale steelmaking factory. The integrated simulation model introduces a set of optimizing alternatives through sensitivity analysis. The simulation model is built by considering all major and detailed operations and interacting systems of the blast furnace workshop. The workshop is composed two parallel blast furnace each containing of a joint raw material storage and furnace and cast-iron stations. Furthermore, there are 54 operations for each blast furnace workshop. The results and the structure of the integrated simulation model were verified and validated by comparative analysis and t-test. Moreover, the monthly production rate of cast-iron station is chosen as the performance measure for the actual system and simulation model in a twelve months trial. The results of t-test shows the average monthly production of cast-iron for the two system is statistically equal (at α=0.05). Also, the industrial engineering unit and the production managers accredited the integrated model. After this stage, the simulation was run for a period of six months to evaluate major bottlenecks in the system. Finally, two optimizing alternatives, which can save the company millions of Dollars, are introduced and their economic advantages are discussed. The integrated simulation model has several unique features. First, it is integrated and considers all operations, maintenance, repairs, quality control activities, systems' limitations and interaction with other systems. Second, it is coded in parametric fashion so any alternative may be easily retrieved. Third, it is a practical tool due to its verification, validation and accreditation. Finally, a standard procedure for development of integrated simulation model for similar blast furnace or workshops is introduced.

Effects of Light and Heavy Rare Earths on Anti-Degradation of Nodular Cast Iron

The effects of rare earths with different contents on anti-degradation of Y base heavy rare earths-magnesium and cerium base light rare earths-magnesium nodular cast iron were studied. Curves of the relationship between the spheroidization grade of liguid iron treated by different nodulizers and holding time were obtained. The results show that the more the remains of the rare earth, the longer the anti-degradation time, the liquid iron was treated either by Y-Mg-Si or by Ce-Mg-Si nodulizer. When the rare earth remains are above certain quantity, the spheroidization grade starts to decline. When liquid iron treated by either Y-Mg-Si or Ce-Mg-Si nodulizer with proper remains of rare earths about 0.04% ∼ 0.06% (mass fraction), the anti-degradation is the best, and the remains of Mg being about 0.04% ∼ 0.07% (mass fraction). Rare earths-Mg nodulizer with moderate RE remains is better than that of Mg-Si nodulizer in anti-degradation property. However, Y-Mg-Si nodulizer with moderate remins of Re is better than Ce-Mg-Si nodulizer. Sometimes Ce-Mg-Si nodulizer can be used for the production of heavy section nodular cast iron.