Why Is Ductile Iron Pipe Stronger Than Ordinary Cast Iron?

The graphite in ordinary cast iron is the existence of the chip, the strength of graphite is very low, so the proportion of cast iron exist flaky open space, ductile iron pipe is relatively low, more brittle than ordinary iron strength.

Graphite cast iron in the graphite is spherical, equivalent to cast iron in the presence of many spherical open space. Spherical open space on the cast iron strength than the flaky open space is small, so the ductile iron pipe strength is much higher than the strength of ordinary cast iron.