以铸造缺陷统计分析及扫描电镜观察为依据，对国内球铁活塞环单体铸造难以起步的技术难题即普遍存在的“黑心”缺陷的成因及实质进行了初步分析，认为这是一种具有一定程度氧化的缩松缺陷．同时，还在实验室做了成功的验证，研制出的球铁活塞环没有出现“黑心”缺陷． According to the statistical analysis of casting defects and the scanning electron microscope observation, the author analyzed the cause and essence of the ubiquitous “black heart” defect, which is the difficult technical problem of the domestic ductile iron piston ring casting, Degree of oxidized shrinkage defects. At the same time, the laboratory has also done a successful verification, developed ductile iron piston rings did not appear “black heart” defects.