锅炉装置屏式过热器爆管失效分析

Failure Analysis of Platen Superheater Tube Explosion in Boiler

某电厂锅炉联合装置经过长时间运行,在大修结束重启运行后发生屏式过热器爆管。结合爆口的形貌特征,通过管壁测厚、化学成分分析、室温拉伸试验、显微维氏硬度试验、金相分析及扫描电镜及能谱分析等试验方法对爆管进行失效原因分析。结果表明:屏式过热器管道在长期运行过程中产生较厚氧化层皮并不断脱落导致壁厚严重减薄,高温导致炉管材料老化严重、性能下降,最终承受不住管道运行压力而爆管。

After a long time of operation,the platen superheater tube burst after the boiler combined unit of a power plant was restarted after the overhaul.Combined with the morphology characteristics of the burst,the failure reason of the burst tube was analyzed by tube wall thickness measurement,chemical composition analysis,tensile test at room temperature,Vickers hardness test,metallographic analysis,scanning electron microscope and energy spectrum analysis.The results show that the platen superheater pipe produces thick oxide layer and continuously falls off during the long-term operation,resulting in serious wall thickness thinning,and the high temperature causes serious aging of furnace tube materials,performance degradation,and finally burst due to the inability to withstand the operating pressure of the pipe.