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1

Model of Cu-Al-Fe-Ni bronze crystallization

Pisarek B. P.

Archives of Foundry Engineering

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2013

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Vol. 13, iss. 3

72--79

EN

According to the analysis of the current state of the knowledge shows that there is little information on the process of phase transformations that occur during the cooling Cu-Al-Fe-Ni hypo-eutectoid bronzes with additions of Cr, Mo and/or W, made additions individually or together, for the determination of: the type of crystallizing phases, crystallizing phases, order and place of their nucleation. On the basis of recorded using thermal and derivative analysis of thermal effects phases crystallization or their systems, analysis of the microstructure formed during crystallization - observed on the metallographic specimen casting ATD10-PŁ probe, analysis of the existing phase equilibrium diagrams forming elements tested Cu-Al-Fe-Ni bronze, with additions of Cr, Mo, W and/or Si developed an original model of crystallization and phase transformation in the solid state, the casting of high quality Cu-Al-Fe-Ni bronze comprising: crystallizing type phase, crystallizing phase sequence, place of nucleation.

2

Numerical modelling of solidification process using interval boundary element method

Piasecka-Belkhayat A.

Archives of Foundry Engineering

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2008

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Vol. 8, iss. 4

171-176

EN

In this paper an application of the interval boundary element method for solving problems with interval thermal parameters and interval source function in a system casting-mould is presented. The task is treated as a boundary-initial problem in which the crystallization model proposed by Mehl-Johnson-Avrami-Kolmogorov has been applied. The numerical solution of the problem discussed has been obtained on the basis of the interval boundary element method (IBEM). The interval Gauss elimination method with the decomposition procedure has been applied to solve the obtained interval system of equations. In the final part of the paper, results of numerical computations are shown.

3

Modeling of phase transformation in ductile cast iron

Fraś E., Kapturkiewicz W., Burbelko A. A., Lopez H. F.

Archiwum Odlewnictwa

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2001

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R. 1, nr 1

103--111

EN

A model of the process and a simulation program were developed to trace the cooling of a nodular graphite iron casting from the beginning of solidification till the ambient temperature. The model uses the previously developed model of solidification (allowing for the nucleation and growth of eutectic grains), the heat transfer and mass diffusion equations for transient conditions pertinent to Fe-C-Si system. The kinetics of graphite and ferrite growth controlled by carbon diffusion was taken into consideration. The possibility of pearlite precipitation was assumed using a relationship of Avrami type, based on the general empirical data. The developed simulation program enables determination of the kinetics of growth of graphite, austenite, ferrite and possibly also pearlite on the casting cross-section as well as grain density related to boundary conditions of the casting cooling. The computed values of the temperature of a plate casting poured in sand mold, of the volume fraction of graphite, ferrite and pearlite, and of the grain density on the casting cross-section were compared with the experimental results.

PL

Opracowano model procesu i program symulacyjny pokazujący przebieg stygnięcia odlewu z żeliwa sferoidalnego od początku krystalizacji do zakończenia przemiany eutektoidalnej. Wykorzystano opracowany wcześniej model krystalizacji, uwzględniający zarodkowanie i wzrost ziaren, przewodzenie ciepła i dyfuzję masy dla warunków nie-ustalonych wraz z warunkami brzegowymi na granicach grafit-ferryt-austenit, determinowanych układem Fe-C-Si. Uwzględniono kinetykę wzrostu grafitu i ferrytu kontrolowaną przez dyfuzję węgla. Przewidziano możliwość wydzielania się perlitu z wykorzystaniem zależności typu Avramiego, opartej na uogólnionych danych empirycznych. Opracowany program symulacyjny umożliwia wyznaczenie kinetyki wzrostu grafitu, austenitu, ferrytu i ewentualnie perlitu w przekroju odlewu, a także gęstości ziaren w połączeniu z warunkami brzegowymi stygnięcia odlewu. Temperatura w odlewie płyty wykonanej w formie piaskowej, objętości grafitu, ferrytu i perlitu oraz gęstość ziaren w przekroju odlewu zostały skonfrontowane z eksperymentem.