Detail publikace

Numerický model heterogenity tvárné litiny

STRÁNSKÝ, K. KAVIČKA, F. SEKANINA, B. ŠTĚTINA, J. DOBROVSKÁ, J.

Český název

Numerický model heterogenity tvárné litiny

Anglický název

Numerical model of heterogeneity of the ductile cast-iron

Typ

článek v časopise - ostatní, Jost

Jazyk

en

Originální abstrakt

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.

Český abstrakt

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.

Anglický abstrakt

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.

Klíčová slova česky

tvárná litina, doba tuhnutí, segregace, strukturální charakteristika, modelování

Klíčová slova anglicky

ductile cast-iron, solidification time, segregation, structural characteristic, modelling

Rok RIV

2009

Vydáno

20.10.2009

Nakladatel

IMŽ

Místo

Gliwice

ISSN

0137-9941

Časopis

Prace Instytutu Metalurgii Zelaza

Ročník

61

Číslo

5

Strany od–do

137–141

Počet stran

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"
}