Due to the spheroidal graphite microstructure of ductile iron, ductile iron is superior to cast steel in terms of reducing vibration, so it is more conducive to reducing stress. An important reason for choosing ductile iron is that ductile iron is less expensive than cast steel. The low cost of ductile iron makes this material more popular, casting efficiency is higher, and it also reduces the cost of machining ductile iron.
The strength of ductile iron is comparable to that of cast steel. Ductile iron has a higher yield strength, with a minimum yield strength of 40k, while cast steel has a yield strength of only 36k. In most municipal applications, such as water, salt water, steam, etc., the corrosion resistance and oxidation resistance of ductile iron exceeds that of cast steel.
