某厂乙烯装置的进料线管弯头在运行过程中多次发生泄漏。通过宏观分析、化学成分分析、硬度测试、金相检验、扫描电镜和能谱分析、石脑油中硫含量分析等方法对弯头的泄漏原因进行了分析。结果表明：高温硫化物腐蚀是弯头泄漏的主要原因，物料的反复冲刷破坏了腐蚀产物膜，腐蚀产物膜的反复去除又加速了弯头的腐蚀。因此，弯头在高温硫化物腐蚀与物料冲刷的交互作用下，在弯头背弯处发生腐蚀穿孔，最终导致弯头泄漏。

The elbow of feed line pipe of ethylene plant in a factory had been leaking for many times during its operation. The causes of elbow leakage were analyzed by means of macro analysis, chemical composition analysis, hardness test, metallographic examination, scanning electron microscope analysis, energy spectrum analysis, and sulfur content analysis in naphtha. The results show that high temperature sulfide corrosion was the main cause of elbow leakage. Repeated scouring of the material destroyed the corrosion product film, the repeated removal of corrosion product film accelerated the corrosion of elbow. Therefore, under the interaction of high temperature sulfide corrosion and material scouring, corrosion perforation occurred at the elbow back bend, which eventually led to elbow leakage.