In paper problem concerning modification of grey cast iron EN-GJL-200 Grade, which is realized mainly by intensification of liquid metal movement in horizontal continuous casting mould containing electromagnetic stirrer is presented. The range of studies contains influence of electromagnetic field on morphology of graphite and usable properties i.e. tensile strength, hardness and machinability. Moreover the influence of velocity of ingot pulling on microstructure was analyzed. The results of studies and their analysis show possibility of improvement in quality of grey cast iron continuous ingot firstly in result of elimination of hard spots in structure by properly selection of velocity of ingot pulling and second in result of unification of size, shape and distribution of flake graphite by application of electromagnetic field.
PL
W pracy przedstawiono problematykę modyfikacji żeliwa szarego gatunku EN-GJL-200 realizowanej głównie poprzez intensyfikację ruchu ciekłego metalu w krystalizatorze zawierającym mieszadło elektromagnetyczne w procesie poziomego odlewania ciągłego. Zakres badań obejmował badania wpływu pola elektromagnetycznego na morfologię grafitu oraz właściwości użytkowe tj. wytrzymałości na rozciąganie, twardości oraz skrawalność. Ponadto analizowano wpływ prędkości wyciągania wlewka na jego mikrostrukturę. Wyniki badań oraz ich analiza pokazały, że istnieje możliwość poprawy jakości wlewka ciągłego z żeliwa szarego po pierwsze w wyniku wyeliminowania ze mikrostruktury zabieleń poprzez właściwie dobraną prędkości wyciągania oraz po drugie w wyniku ujednorodnienia wielkości, kształtu oraz rozmieszczenia grafitu płatkowego poprzez zastosowanie oddziaływania pola elektromagnetycznego.
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Purpose: The main aim of investigations was to describe the influence of the electromagnetic on the structure of grey cast iron obtained in the continuous casting process. Design/methodology/approach: To investigations the grey cast iron ingots a continuous casting laboratory stand was used. The stand contains continuous casting mould with inductor of rotate electromagnetic field. The research includes also the metallographic researches on scanning electron microscope and investigations of usable properties i.e. measurements of hardness and machinability. Findings: The results of investigations and their analysis show possibility of unification of flake graphite morphology in cast iron structure, and distribution of hardness on cross-section of ingot and its machinability. Research limitations/implications: In further research, authors of this paper are going to application of introduced method of continuous casting with use of electromagnetic field in industrial tests. Practical implications: The work presents method of unification of structure and properties, which are particularly important in continuous casting. Uniform morphology of flake graphite in structure of cast iron ingots for automobile industry is very important in viewpoint of machinability. Originality/value: Contributes to improvement in quality of grey cast iron continuous casted ingots.
Structure, and thus the mechanical properties of steel are primarily a function of chemical composition and the solidification process which can be influenced by the application of the inoculation treatment. This effect depends on the modifier used. The article presents the results of studies designed to assess the effects of structural low alloy steel inoculation by selected modifying additives. The study was performed on nine casts modeled with different inoculants, assessment of the procedure impact was based on the macrostructure of made castings. The ratio of surface area equivalent to the axial zone of the crystals and columnar crystals zone was adopted as a measure of the inoculation effect.
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Cast ingot pulling speed is significantly affecting the nature of the resulting structure and the quality of the outer surface of the ingot. By introducing a variable algorithm for extraction of the ingot we may to some extent control the shape and location of the solid / liquid interface and temperature field in the cross-section of the ingot. The shape of the crystallization front, as well as its position relative to mold plays an important role in the process of continuous casting ingots of grey iron and affects the structure of the casting. In order to verify the impact of an algorithm on the shape and the location of solid / liquid interface, a number of simulations in ANSYS Fluent 12 were made, for determining the shape of crystallization front and temperature distribution on the cross-section of the ingot.
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Purpose: The main aim of investigations was the unification of flake graphite morphology in cast iron ingots in conditions of forced convection of liquid metal in the continuous casting mould, which contains electromagnetic stirrer. Design/methodology/approach: To investigations of grey cast iron ingots were used laboratory stand of continuous casting, which contains continuous casting mould with inductor of rotate electromagnetic field. To investigations were made metallographic researches on scanning electron microscope and investigations of usable properties i.e. measurements of hardness and machinability. Findings: The results of investigations and their analysis show possibility of unification of flake graphite morphology in cast iron structure, and distribution of hardness on cross-section of ingot and its machinability. Research limitations/implications: In further research, authors of this paper are going to application of introduced method of continuous casting with use of electromagnetic field in industrial tests. Practical implications: The work presents method of unification of structure and properties, which are particularly important in continuous casting. Uniform morphology of flake graphite in structure of cast iron ingots for automobile industry is very important in viewpoint of machinability. Originality/value: Contributes to improvement in quality of grey cast iron continuous casted ingots.
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The article describes the construction of a 20 mm diameter grey cast iron ingots continuous casting laboratory line. This line is made of three main units: melting unit (induction furnace), casting unit and the pulling unit. In order to improve the homogeneity of the microstructure of ingots (by applying forced convection of liquid metal during the crystallization process) in this case a crystallizer system generating the forced movement of liquid metal based on a system of electrical power windings of the AC specific frequency. This solution allowed to obtain a homogeneous microstructure of the continuous casting of cast iron EN-GJL-200 species.
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Cast ingot pulling speed significantly affects the nature of the resulting structure and the quality of the external surface. By introducing a variable ingot pulling algorithm allows to some extent to control the shape and location of the crystallization front and temperature field in the ingot cross section. The shape of the crystallization front, and its position relative to the crystallizer plays an important role in the continuous casting of iron ingots affecting the structure of the casting. In order to verify the impact of the ingot pulling algorithm to the shape and the location of the front of crystallization a series of simulations in ANSYS FLUENT 12 was carried out.
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Purpose: The first aim of investigations was the reduction of grain size and unification of structure for pure Al casting by introduction of small amount of inoculant (less than obligatory standard PN-EN 573-3, which concerning about aluminium purity) and with electromagnetic field. The second aim was to determination of electromagnetic field influence on morphology of graphite in cast iron ingots, which were poured with variable founding parameters. Design/methodology/approach: To investigations of pure Al and grey cast iron were used two types of rotate electromagnetic field i.e. without reversion (WPM) and with reversion and with a pause between following changes of electromagnetic field direction (IRPM). Findings: The results of investigations and their analysis show possibility of effective inoculation of pure aluminium structure by use of influencing of stirring electromagnetic field into metal during solidification and inoculation by introducing AlTi5B1 inoculant into liquid aluminium. Moreover results of studies show advantageous influence of electromagnetic field on graphite morphology. Research limitations/implications: In further researches, authors of this paper are going to apply his method of inoculation in industrial tests. Practical implications: The work presents a method of structure refinement which is particularly important in continuous and semi – continuous casting. In pure metals large columnar crystals zone result in forces extrusion rate reduction and during the ingot rolling delamination of external layers can occur. Thus, in some cases ingot skinning is needed, which rises the production costs. Whereas morphology of graphite in cast iron ingots for automobile industry is very important in viewpoint of wear resistance. Originality/value: Contributes to research on size reduction in pure metals structure and forming of graphite in cast iron.
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In the national [1] and foreign [2] literature the methods of improving the homogeneity of the structure of castings using forced convection of the solidifying metal in the casting mould or the crystallizer are presented. This article presents the influence of chosen parameters of the rotating electromagnetic filed that is forcing the movement of melted metal in the mould on the morphology of graphite and the abrasive wear of the grey cast iron. The effect of this examination is the obtained modification of the flake graphite divisions morphology and a alteration of the abrasive wear resistance of the castings manufactured this way.
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One way to improve the unification of the casting structure may be the application of forced convection of liquid metal during the crystallization in the form or continuous casting mould. This paper presents the results describing the influence of selected parameters of rotating electromagnetic field enforcing the movement of liquid metal in the form on the morphology of graphite in grey cast iron. The results were fragmented graphite flakes in conditions of regulating the rate of cooling in the range of temperature [...] and casting with the influence of electromagnetic field.
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