钢丝绳索具用闭式索节断裂失效分析

Fracture Failure Analysis of Closed Socket for Steel Wire Rope Sling

采用宏观断口形貌、化学成分、力学性能分析,光学显微镜及扫描电镜组织分析等对失效索节进行了断裂机理研究。结果表明,索节失效断裂主要原因是由于铸造工艺不当引起的中心缩孔以及中心偏析,并且存在过烧引起的熔洞以及枝晶状铸造组织,这些缺陷降低了索节的力学性能。索节在受力作用下,心部的中心孔洞为断裂源首先失效,进而从心部向外失效断裂。

The fracture mechanism of the failed socket was studied by analysis of macroscopic fracture morphology,chemical composition, mechanical properties and microstructure observation by optical microscope and scanning electron microscope. The results show that the main causes for the failure of the socket are central shrinkage and segregation due to improper casting process, melting holes and dendritic casting structure caused by overburning. These defects reduces the mechanical properties of the socket. Under the action of force, the central hole in the core as the fracture source fail firstly, and then the fracture occurs from the core center to outside.