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Abstract

Today’s industry aims at such situation, where number of defective products, so called defects shall approach to zero. Therefore, one introduces a various changes in technology of production, introduces improvements which would help in accomplishment of this objective. Another important factor is introduction of different type of testing, which shall help in assessment which factor has significant effect on quantity of rejects, and which one could be neglected. Existence of casting rejects is unavoidable; therefore a new ideas, technologies and innovations are necessary in the entire widely understood foundry branch, in order to minimize such adverse effect. Performance of tests aimed at unequivocal determination of an effect of vibrations during crystallization on mechanical properties and porosity of the EN ACAlSi17 alloy was the objective of the present work. To do this, there were produced 36 castings from EN AC-AlSi17 alloy. All the castings underwent machining operations. Half of the casting was destined to strength tests, the other half served to determination of an effect of vibrations on porosity of the alloy. The specimens were divided into 12 groups, depending on amplitude of vibrations and tilt angle of metal mould during pouring operation.

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Authors and Affiliations

T. Ciućka
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Abstract

An innovative method for determining the structural zones in the large static steel ingots has been described. It is based on the

mathematical interpretation of some functions obtained due to simulation of temperature field and thermal gradient field for solidifying

massive ingot. The method is associated with the extrema of an analyzed function and with its points of inflection. Particularly, the CET

transformation is predicted as a time-consuming transition from the columnar- into equiaxed structure. The equations dealing with heat

transfer balance for the continuous casting are presented and used for the simulation of temperature field in the solidifying virtual static

brass ingot. The developed method for the prediction of structural zones formation is applied to determine these zones in the solidifying

brass static ingot. Some differences / similarities between structure formation during solidification of the steel static ingot and virtual brass

static ingot are studied. The developed method allows to predict the following structural zones: fine columnar grains zone, (FC), columnar

grains zone, (C), equiaxed grains zone, (E). The FCCT-transformation and CET-transformation are forecast as sharp transitions of the

analyzed structures. Similarities between steel static ingot morphology and that predicted for the virtual brass static ingot are described.

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Authors and Affiliations

A.A. Ivanova
B. Kania
P. Kwapisiński
W. Wołczyński
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Abstract

The Structural Peclet Number has been estimated experimentally by analyzing the morphology of the continuously cast brass ingots. It

allowed to adapt a proper development of the Ivantsov’s series in order to formulate the Growth Law for the columnar structure formation

in the brass ingots solidified in stationary condition. Simultaneously, the Thermal Peclet Number together with the Biot, Stefan, and

Fourier Numbers is used in the model describing the heat transfer connected with the so-called contact layer (air gap between an ingot and

crystallizer). It lead to define the shape and position of the s/l interface in the brass ingot subjected to the vertical continuous displacement

within the crystallizer (in gravity). Particularly, a comparison of the shape of the simulated s/l interface at the axis of the continuously cast

brass ingot with the real shape revealed at the ingot axis is delivered. Structural zones in the continuously cast brass ingot are revealed: FC

– fine columnar grains, C – columnar grains, E – equiaxed grains, SC – single crystal situated axially.

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Authors and Affiliations

A.A. Ivanova
Z. Lipnicki
P. Kwapisiński
W. Wołczyński

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