Ductile Iron, also called ductile cast iron or spheroidal graphite iron, is a cast iron type typically rich in graphite content. Ductile iron exhibits greater fatigue resistance due to its nodular structure.  The application of ductile iron is diverse, including automobiles and water lines. Therefore, ductile iron is very popular among industrial manufacturers. Before we go further into the specifics of ductile iron, we need to understand what it is on a high level. Ductile iron is a cast iron category which is known for its flexibility, fatigue resistance, durability, and robustness.  Though ductile iron displays the same set of physical properties similar to those of steel, ductile iron can be shaped into any form without any hurdles. 

Read the History of Ductile Iron

Ductile Iron has special properties like that of the spherical graphite components, which differentiate it from the likes of cast iron. Ductile casting is made using ductile iron, where the discharge of molten iron into voids produces the desired shape. The cooling down of the molten iron that is poured solidifies into any shape required by our client. Ductile iron is manufactured from raw pig iron, which characterizes a high percentage of iron; it is made in the furnace flames, by adding a high amount of carbon. 

To produce different grades of ductile iron, the matrix structure around the graphite must be controlled during the casting process or through many heat treatment processes. There are minor compositional differences between different ductile iron grades so as to create the required matrix (microstructures). Ductile iron, therefore, is considered as steel with graphite steroids distributed across its matrix. The qualities of the metallic matrix in which the graphite spheroids are suspended impact the physical properties of ductile iron, but the graphite spheroids themselves don’t. More to come in the subsequent part of the blog.