Contents of Cast Iron

Cast Iron (CI) is prepared form melting pig iron in electric furnace or in cupola furnace. Electric furnace gives better quality.CI contains different elements in addition to Fe. The carbon content of CI is more than 2%. Si varies between 0.5 to 3.0%. It is very important because it controls the form of C in CI. S content in CI varies between 0.06 to 0.12% and is largely present as FeS which tends to melt at comparatively low temperature causing hot shortness. Mn inhibits formation of FeS.

Though P increases fluidity of CI – a property helpful for pouring – it has to be restricted to 0.1 to 0.3% because it reduces toughness. P is present in the form of FeP. Mn in CI varies from 0.1 to 1.0% through such a small Mn does not affect properties of CI it certainly helps improve upon hot shortness by taking care of S.

Several other alloying elements like Ni, Cr, Mo, Mg, Cu and V may be added to CI to obtain several desirable properties.