锅炉高温过热器泄漏原因分析

Analysis of the Crack and Leak of the Elbow of the Hightemperature Superheater

某锅炉因高温过热器的弯头开裂导致泄漏而停炉。本文通过宏观检查分析、射线探伤分析、拉伸试验,显微维氏硬度、化学分析、金相分析等方法对弯头开裂原因进行分析,结果显示弯管热弯温度超高,导致弯头存在晶间腐蚀倾向。锅炉运行过程中,弯管在管内腐蚀介质和应力的作用下,裂纹形成并迅速扩展,最终发生泄漏。

A boiler was shut down because of the crack and leak of the elbow of the high temperature superheater.The cracking reason was analyzed by the mean of macroexamination,x ray radiographic examination,tensile test,micro-vickers hardness,chemical composition analysis,metallographic analysis.The results showed that the hotbending temperature of the pipe is extremely high,which means pipe had intergranular corrosion tendency.Crack formed and propagated rapidly under the action of corrosive medium and stress in the pipe when the boiler worked.Eventually there was a leak.