发动机作动筒裂纹分析

发动机作动筒末端件孔边是裂纹故障多发部位,严重影响使用安全。对作动筒典型失效结构件进行断口观察、能谱分析,结果表明：断口上有明显的腐蚀产物和沿晶断裂特征;在裂纹源区、扩展区和裂纹尖端都出现了Na、K和Cl等杂质元素,具有典型的腐蚀特征;进一步对作动筒结构的力学分析表明,在使用过程中故障部位存在一定的拉应力,综合判断孔边裂纹失效模式为应力腐蚀开裂,腐蚀介质主要来自含Cl元素较多的潮湿使用环境。该研究结果对此类作动筒的使用和故障预防提供了借鉴。

Failure Analysis of Actuating Cylinder of an Engine

Cracks often appeared in the actuating cylinders of an engine which results in decreasing the security.Firstly,the fractography of a representative actuating cylinders is observed and analyzed.The characteristics of mud-crack pattern and intercrystalline fracture are obvious.Secondly,energy-dispersive spectrometry method is used to analyze the corrosion product.The Na and Cl elements are detected in the crack.Results show that the failure is due to stress corrosion cracking,the components of the actuating cylinder is accordance with the relevant parameters and the corrosion is mainly caused by the medium in working environment.These results are very significant for failure analysis and prevention of the actuating cylinder.