SPHEROIDAL GRAPHITE CAST IRON WITH EXCELLENT GAS DEFECT RESISTANCE

摘要

There is provided with spheroidal graphite cast iron having excellent gas defect resistance where gas defects such as pinholes attributable to the free N are small in number and having mechanical characteristics and machinability equal to or greater than the conventional ones. The spheroidal graphite cast iron consists of, in mass ratio, C: 3.3 to 4%; Si: 2 to 3%; P: not more than 0.05%; S: not more than 0.02%; Mn: not more than 0.8%; Cu: not more than 0.8% (0 is not included); Mg: 0.02 to 0.06%;,Ti: 0.01 to 0.04%; V: 0.001 to 0.01%; Nb: 0.001 to 0.01%; and N: 0.004 to 0.008%, with the remnant substantially consisting of Fe and an inevitable impurity.