锅炉管爆管失效分析

Failure analysis of the bursting of boiler pipes

某锅炉发生锅炉管爆管失效。文中利用金相显微镜、直读光谱仪,扫描电镜等对失效管道进行了分析,结果表明:失效钢管是在高温高压下发生氢腐蚀,使钢管内壁发生腐蚀,形成大量的晶界裂纹,同时发生氧化反应,生成较厚的氧化垢层。当停炉或负荷变化较大时,管壁上的氧化垢层容易发生剥落,并在某处聚集,引起水流不畅或阻塞,使阻塞部位的钢管短时升温剧烈,发生过热爆管。

Since bursting failure occurred at the boiler pipes,failure pipes were analyzed by metalloscope,direct-reading spectrometry,scanning electron microscope,etc.in this paper.The results show that hydrogen attack occurs at high temperature and high pressure,which resulted in corrosion of pipe wall,forming a large number of grain boundary cracks.At the same time,an oxidation reaction occurs,resulting in a thicker oxide scale layer.When the furnace was shut down or the load changed greatly,the oxide scale layer on the pipe wall was easy to peel off and gather in some place,which caused the water flow to be blocked,and caused the steel pipe in the blocked part to heat up violently for a short time,resulting in overheating pipe bursting.