Disadvantages of ductile iron pipes
In most municipal applications, such as water, brine, steam, ductile iron has more corrosion resistance and oxidation resistance than cast steel. Because of the spheroidal graphite microstructure of nodular cast iron, nodular cast iron is superior to cast steel in reducing vibration ability, so it is more beneficial to reduce stress. An important reason for choosing ductile iron is that ductile iron costs less than cast steel.
The strength of nodular cast iron is comparable to that of cast steel. Ductile iron has higher yield strength, the lowest yield strength is 40K, while the yield strength of cast steel is only 36k.
Compared with cast iron, ductile iron has an absolute advantage in strength. The tensile strength of ductile iron is 60K, while the tensile strength of cast iron is only 31k. The yield strength of ductile iron is 40K, while the cast iron does not show yield strength, and eventually breaks. The strength to cost ratio of ductile iron is far superior to that of cast iron.
