Tech Tip – Ductile Iron

How can you be sure that the cast iron parts you have are ductile iron?

At Miller, we expect the foundries, who we source our cast iron parts from, to follow documented requirements that are specifically directed at the qualification of production castings. One of the principal means of evaluating castings is an examination of its microstructure. Microstructure describes a material’s appearance under magnification. The images above represent grey cast iron and ductile iron at 100X magnification. The microstructure of a casting is important because of the relationship to the material’s composition, mechanical properties, processing history and performance. Different cast irons can have similar material compositions and hardness, but because of an uncontrolled pouring process can end up with unwanted structural features. A microstructural examination of ductile iron will show its graphite in the shape of nodules versus flakes as in grey iron.

There is a clear advantage to using ductile iron as opposed to other cast irons, so before you make your next purchase, give us a call to learn more about our safer and more reliable products.

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