This work focuses on the study of the influence of microshrinkage cavities on the plastic deformation and fracture of ferritic ductile iron. Cast samples were especially developed to include dispersed microshrinkage. Tensile testing and digital image correlation analysis are employed to assess the influence of dispersed microshrinkage cavities as preferential sites for crack initiation and propagation under uniaxial static load. The results show that small microshrinkage cavities of up to 3.5 times the area of graphite nodules are not linked to the initiation and propagation of cracks in ductile iron. The methodology developed in this work becomes useful to evaluate the influence of size, distribution, and morphology of different microshrinkage defects on the damage evolution during tensile loading.

这项工作的重点是研究微缩腔对铁素体球墨铸铁塑性变形和断裂的影响。铸造样品特别开发为包括分散的微收缩。拉伸测试和数字图像相关性分析用于评估分散的微缩腔的影响，这些腔是单轴静载荷下裂纹萌生和扩展的优先部位。结果表明，高达3.5倍于石墨结核面积的微缩孔与球墨铸铁中裂纹的萌生和扩展无关。在这项工作中开发的方法对于评估不同的微缩缺陷的尺寸，分布和形态对拉伸载荷过程中损伤演变的影响很有用。