球墨铸铁管用的球墨铸铁是铁的一种，是一种铁、碳和硅的合金。球墨铸铁中石墨是以球状形式存在的，一般石墨大小为6-7级，质量上要求铸铁管的球墨化等级控制为1-3级（球化率≥80%），因材料本身的机械性能得到较好的改善，具有铁的本质，钢的性能。退货后的球墨铸铁管，其金相组织为铁素体家少量珠光体，机械性能较好。


　　Ductile iron pipe ductile iron is a kind of iron, is a kind of iron, carbon and silicon alloy. Exists in the form of spherical graphite in ductile iron, the graphite size for 6-7, the quality requirements of cast iron pipe, ductile hierarchical control for 1-3 (spheroidization rate greater than or equal to 80%), have been improved because of the mechanical properties of the material itself, nature with iron, steel performance. After the return of nodular cast iron pipe, the microstructure is ferrite pearlite home, good mechanical properties.