ISO2531 Ductile iron pipes K9 Length:5.7M OR6M. 125PCS FOR 20GP. 150PCS FOR 40GP Enough experience for exporting. characteristicAnticorrosion strong, good ductibility, Simple installation.chemical compositionMain ingredients: C, Si, Ma, S, Mg etc.metallographic structureIn ferrite and pearlite substrate has a certain number of spherical graphite,minor-calibe:≤20%, large diameter:about25% ...