Publication detail
Numerical model of heterogeneity of the ductile cast-iron
STRÁNSKÝ, K. KAVIČKA, F. SEKANINA, B. ŠTĚTINA, J. DOBROVSKÁ, J.
Czech title
Numerický model heterogenity tvárné litiny
English title
Numerical model of heterogeneity of the ductile cast-iron
Type
journal article - other
Language
en
Original abstract
An original three-dimensional (3D) model of solidification is used to describe the process of solidification and cooling of massive 500x1000x500 mm ductile cast-iron castings. The castings are cast in sand moulds. The calculated mode of the kinetics of the temperature field of the casting is verified during casting with temperature measurements in selected points.The experimental samples – 15 mm in diameter and 12 mm high – are metallographically analysed and also in terms of heterogeneity of the chemical composition. Successively, the local solidification time (i.e. the time the specified position of the casting, remains within the temperature range between the liquidus and solidus) is also calculated using the 3D model. The following dependences are later determined according to the experimental and calculated data: the average size of the graphite spheroids rg, graphite cells Rb and the average distances among the particles of graphite Lg – always as a function of the local solidification time xi, yi, zi . Furthermore, it has been found out that the given basic characteristics of the structure of the cast iron rg, Rb and Lg are directly proportional to the logarithm of the local solidification time. The original spatial model of solidification can therefore be used in its first approximation for the assessment of the pouring structure of massive cast-iron castings.
Czech abstract
Originální třírozměrný model tuhnutí je použit pro popis tuhnutí a chlazení masivního odlitku z tvárné litiny o rozměrech 500x1000x500 mm. Vypočtené průběhy teplotních polí byly ověřeny měřením ve vybraných bodech odlitku. Byly metalograficky analyzovány odebrané vzorky s ohledem na heterogenitu chemického složení. Současně bya použitím modelu teplotního pole vypočtena místní doba tuhnutí. Ukazuje se, že předložené základní charakteristiky struktury jsou přímo úměrné logaritmu místní doby tuhnutí. Získaný model tuhnutí může být použit jako první aproximace pro stanovení struktury masivního odlitku z tvárné litiny.
English abstract
An original three-dimensional (3D) model of solidification is used to describe the process of solidification and cooling of massive 500x1000x500 mm ductile cast-iron castings. The castings are cast in sand moulds. The calculated mode of the kinetics of the temperature field of the casting is verified during casting with temperature measurements in selected points.The experimental samples – 15 mm in diameter and 12 mm high – are metallographically analysed and also in terms of heterogeneity of the chemical composition. Successively, the local solidification time (i.e. the time the specified position of the casting, remains within the temperature range between the liquidus and solidus) is also calculated using the 3D model. The following dependences are later determined according to the experimental and calculated data: the average size of the graphite spheroids rg, graphite cells Rb and the average distances among the particles of graphite Lg – always as a function of the local solidification time xi, yi, zi . Furthermore, it has been found out that the given basic characteristics of the structure of the cast iron rg, Rb and Lg are directly proportional to the logarithm of the local solidification time. The original spatial model of solidification can therefore be used in its first approximation for the assessment of the pouring structure of massive cast-iron castings.
Keywords in Czech
tvárná litina, doba tuhnutí, segregace, strukturální charakteristika, modelování
Keywords in English
ductile cast-iron, solidification time, segregation, structural characteristic, modelling
RIV year
2009
Released
20.10.2009
Publisher
IMŽ
Location
Gliwice
ISSN
0137-9941
Journal
Prace Instytutu Metalurgii Zelaza
Volume
61
Number
5
Pages from–to
137–141
Pages count
5
BIBTEX
@article{BUT48212,
author="Karel {Stránský} and František {Kavička} and Bohumil {Sekanina} and Josef {Štětina} and Jana {Dobrovská},
title="Numerical model of heterogeneity of the ductile cast-iron",
journal="Prace Instytutu Metalurgii Zelaza",
year="2009",
volume="61",
number="5",
month="October",
pages="137--141",
publisher="IMŽ",
address="Gliwice",
issn="0137-9941"
}