High-Si spheroidal graphite (SG) iron is a relatively new addition to the family of SG irons. While the industry has been successful in producing class 500-14 and 600-10 irons there is a paucity of published research data on the efficiency of inoculation on shrinkage and porosity reduction. The critical phase is the end of solidification when, as the amount of eutectic graphite generated decreases, graphite expansion may become insufficient to compensate the solidification shrinkage, increasing the risk of micro-shrinkage (microporosity) formation. The goal of this industrial research was to assess the efficiency of eight commercial inoculants in minimizing porosity occurrence in a 3.45%C, 3.75%Si SG iron. Metallographic analysis was conducted on the TA cups to evaluate the nodule count and size distribution. SEM analysis was used to study the type of nuclei, and tomography to quantify the amount of porosity in each TA cup. An attempt was made to correlate the graphite formation rate during eutectic solidification with the porosity level. Inoculants rich in Zr seem to produce the best results.

高硅球形石墨（SG）铁是SG铁系列中的一个相对较新的成员。尽管该行业已经成功地生产了500-14和600-10级的熨斗，但有关接种对减少收缩率和减少孔隙率的效率的研究数据很少。关键阶段是凝固的终点，当随着共晶石墨生成量的减少，石墨膨胀可能不足以补偿凝固收缩，从而增加微收缩（微孔）形成的风险。这项工业研究的目标是评估八种商用孕育剂在使3.45％C，3.75％Si SG铁中的孔隙率最小化方面的效率。在TA杯上进行金相分析以评估结节数和尺寸分布。SEM分析用于研究原子核的类型，而X线断层摄影术则用于定量每个TA杯中的孔隙率。试图使共晶凝固期间的石墨形成速率与孔隙率水平相关。富含Zr的孕育剂似乎能产生最佳效果。