After being treated with Magnesium the graphite contained in spheroidal cast iron precipitates in the form of spheroids. Spheroidal cast iron has mechanical properties similar to cast steel whereas its wear resistance is typical of alloyed cast iron. Materials are subdivided on the basis of their matrix type: ferrtic/pearlitic , pearlitic and acicular matrix.
These rolls are used mainly in wire, rod, light, medium and heavy section mills. The ferritic/pearlitic matrix is used for roughing stands where high thermal stress can take places, pearlitic types are for roughing and preparing stands and the acicular matrix is rather for pre-finsihing and finishing stands.