采用理化检验方法对超超临界锅炉捞渣机圆环链断裂的原因进行了分析.断口渗碳层的分布规律表明圆环链在制造过程中已存在由外圆表面深入内部的开口裂纹,该制造缺陷是造成圆环链断裂的根本原因.同时,利用ANSYS有限元分析的方法模拟圆环链断裂前后的应力分布规律.结果表明：制造缺陷处的最大拉应力为材料设计破断应力的5.5倍;圆环链一侧直边在制造缺陷处断裂后,最大拉应力分布在圆弧段和另一侧直边段过渡处内侧表面,与最终实际断裂位置相吻合.

Fracture reason for round-linked chain of ultra-supercritical boiler slag conveyor was analyzed by means of physical and chemical testing methods,and the distribution of the carburized layer on fracture surface showed an open crack from the circumferential surface to inside had already existed that was the fundamental reason for the fracture of circular chain.Meanwhile,ANSYS finite element analysis method was employed to simulate the stress distribution law before and after the fracture,and the results showed the maximum tension stress in the position of defect due to the processing of manufacture was 5.5 times of that designed for material fracture.After fracture happened in the manufacture defect of the straight-edge section of circular ring,maximum tension stress distributed in the inner side between circular and straight-edge sections,in agreement of the final actual fracture position.