Nodular Iron Casting is more expensive than gray, but it greatly increases the mechanical characteristics since most of the carbon content in nodular iron has the shape of spheroids. This microstructure produces desirable properties such as high ductility, strength, good machinability, good melt flow, good toughness and toughness.
To produce the nodular structure the molten iron leaving the furnace is inoculated with a small amount of materials such as magnesium, cerium, or both.
The Nodular Foundry is characterized in that the graphite appears in the form of tiny spheres and thus the continuity of the matrix is interrupted much less than when it is in laminar form, this gives rise to a tensile strength and tenacity greater than in the ordinary gray cast iron.
The spheroidal particles of graphite are formed during solidification due to the presence of small amounts of magnesium or cerium.