Metallurgy and Foundry Engineering
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ISSN 1230-2325
e-ISSN: 2300-8377
Issue Date
2005
Volume
Vol. 31
Number
No. 2
Description
Journal Volume
Projects
Pages
Articles
Eutectic transformation in ductile cast iron. Part I - Theoretical background
(2005) Fraś, Edward; Górny, Marcin; López, Hugo F.
In the present paper, heat balance is incorporated in developing expressions for the solidiflcation kinetics of divorced eutectic in ductile cast iron taking into account nucleation and growth processes for spheroidal graphite. Accordingly, a new analytical equations were derived that describe the nodule count N and the chill and chilling tendency CT of ductile cast iron. From this analysis, it is viable to predict cast nodule counts as well as the chill and CT for ductile iron from experimental data on cooling rates, chemical composition and other factors. Finally, the effect of technological factors on the resultant nodule counts the chill and chilling tendency is considered in this work.
Eutectic transformation in ductile cast iron. Part 2 - Experimental verification
(2005) Fraś, Edward; Górny, Marcin; López, Hugo F.
In this work the predictions of a proposed analytical theory aimed at elucidating factors influencing on the nodule counts, the chill and the chilling tendency of nodular cast iron were experimentally verified. The experimental work was focussed on processing nodular cast iron under various inoculation conditions in order to achieve various physicochemical states of the experimental melts. In addition, plates of various wall thicknesses were cast and the resultant chilling tendency was established. Metallographic evaluations were made to determine the exhibited nodule counts in the experimental plates. Moreover, thermal analysis of these nodular cast irons was used to find out the degree of maximum undercooling for the graphite eutectic deltaTm. Finally, calculations were made using previously derived analytical expressions to determine graphite nodule counts, chilling tendency and critical wall thicknesses, below which the chill appears. From this analysis, it was found that there is good agreement between the theoretical predictions and the experimental outcome.
The theoretical background for calculation of geometrical parameters of the stable melting zone in single-row coke cupolas
(2005) Longa, Władysław; Khatemi, Belkheir
In the present work, the stable melting zone was divided into sequences (systems) of the melting pieces of metal, to derive next some equations used in calculation of the mean volume and surface area of the pieces in individual sequences (for plates of any arbitrary value of their relative dimensions). The analysis of the obtained relationships has proved that in calculation of the geometrical parameters of the melting zone (zone height, mass of melting metal, surface of development, number of the melting pieces of metal) it is possible to use the term of a mean integral volume and mean integral surface area of the pieces of metal in a zone.
Graphite particle size distribution in nodular cast iron
(2005) Wiencek, Kurt; Skowronek, Tadeusz; Khatemi, Belkheir
A system of non-overlapping random spheres, whose diameters have the Weibull distribution may be used as a model for the graphite in nodule cast iron. For a given material the model probability density function of the Weibull distribution may be determined (as the first approximation) by fitting the PDF of model profile diameters to the one of graphite particle sections. The Weibull distribution may be used as the basis for quantitative metallography of the graphite phase in nodular cast iron.
An effect of aromatic diluent addition on the selected properties of epoxy resin
(2005) Hutera, Barbara; Drożyński, Dariusz
The article describes the studies which have been conducted on the dynamic wetting of quartz grains by EPIDIAN 5 resin and by this resin with an addition of 5 wt. %, 20 wt. % and 30 wt. % of xylene at different temperatures. In the case of the investigated resin, the wetting process dynamics is best described by a logarithmic function: theta = A Int + B0, where: theta is the contact angle after time t, and A and B0 are constants characteristic of this process at a given temperature. It has been proved that with 5 wt. % addition of xylene both constants assume a value different than zero. With addition of 20 wt. % and 30 wt. % of xylene, the State of equilibrium is reached almost immediately, and it is expressed by a zero value of constant A. The infrared spectroscopy did not reveal the presence of any chemical reactions between the EPIDIAN 5 resin and xylene, thus confirming that the chemical structure of xylene molecule affects the type of interaction and proves the non-active behaviour of xylene as a diluent. The importance of the studies for foundry sand practice has been stressed.