录井钢丝断裂的失效分析

Failure Analysis of Logging Steel Wire Fracture

针对录井钢丝的断裂原因,对事故钢丝和未使用钢丝进行宏观形貌和金相组织的对比分析,对钢丝表面的点蚀坑进行能谱分析,对断口进行扫描电镜分析。结果表明,油井中的钢丝表面腐蚀坑和裂纹源区均含有Cl元素,腐蚀介质是引起钢丝断裂的主要原因。在腐蚀性介质和外加载荷的双重作用下,裂纹持续扩展,直至发生疲劳断裂。

To analyze the fracture reason of well logging wire, the invalid and unused steel wire were compared and analyzed about macro-profile and metallurgical structure. The corrosion pit in steel wire surface was analyzed by energy spectrum, the fracture was analyzed by SEM. The results show that the both steel wire surface corrosive pit and crack origin area contain C1 element, the corrosive medium is main causes of well logging steel wire fracture. Under the dual influence of corrosive medium and applied load,the crack expands continuously,until the fracture happens.