Nodular Graphite Cast Iron
Nodular graphite cast iron is a type of cast iron with the graphite having the shape of spheric in its composition. It is also called “SPHERICAL CAST IRON”. A small amount of magnesium (mg) or cerium (ce) is added to the molten cast iron in order to convert the carbon from lamellar to spherical shape. This specially obtained cast iron is called nodular graphite cast iron because of its graphite structure.Nodular graphite impart softness (ductility) to cast iron. Its broken surface is shiny.
The Making of the Nodular Graphite
Chemical Composition
The chemical composition of ductile iron is generally within the following limits. (Table 1.1).
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% Composition |
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|
Carbon |
(C) |
3.00-4.00 |
|
Silicium |
(Si) |
2.00-3.00 |
|
Mangan |
(Mn) |
0.10-0.90 |
|
Phosphor |
(P) |
0.10 Max. |
|
Sulfur |
(S) |
0.03 Max |
|
Magnesium |
(Mg) |
0.030-0.080 |
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Table 1.1: KGDD chemical composition |
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Microstructure and Chemical Properties of Nodular Graphite Cast Irons |
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Material Type |
GGG 40 |
GGG 50 |
GGG 60 |
GGG 70 |
GGG 80 |
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Micro Structure |
FERRITIC |
PERLITIC |
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Table 1.2: KGDD microstructure properties |
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