乙烯装置废热锅炉泄漏失效分析

Failure analysis for the leakage on a gastube boiler in Service

乙烯装置废热锅炉是乙烯裂解装置正常运行的关键设备,其换热管泄漏是其主要的失效形式。本文对废热锅炉泄漏部位进行了分析和研究,通过采用化学分析的方法研究了其换热管和管板的材质是否满足标准的要求,采用金相检测的方法确定材质是否在长时间的使用过程中发生了材质变化,扫描电镜用来研究表面的腐蚀形貌,能谱分析用来确定表面的腐蚀物质的元素成分,物相分析用来确定腐蚀产物的物质成分。分析结果表明:碱腐蚀是造成废热锅炉泄漏的原因。

Gastube boiler was used to cool pyrolysis gas and produce high pressure steam in the Ethylene cracking plant, gastube boiler was one of the key equipment in the Ethylene cracking plant. The failure of heat exchange tube leakage is the main modes for a gastube boiler of long-term service. In this paper, the leak of the gastube boiler was observed and investigated. Chemical analysis was employed to study heat exchange tube and tube sheet’s Material composition, Metallographic inspection was employed to detect the material degradation of heat exchange tube and tube sheet material after being used for a long-term, Scanning electron microscopy(SEM) was employed to study the surface corrosion morphology, Spectrum analysis was employed to study the elemental composition of corrosion on the surface of the material, and Phase analysis were employed to study the composition of the corrosion products. the results shows that the gastube boiler’s leakage was caused by Alkali corrosion.