某电厂锅炉屏式过热器爆管原因分析  

Failure Analysis on Tube-bursting of Platen Superheater in a Power Plant

作　　者：赵中赫 刘光奎[2] 梁宝琦 龚巍[1] 郝维勋[1] Zhao Zhonghe;Liu Guangkui;Liang Baoqi;Gong Wei;Hao Weixun(Harbin Boiler Company Limited,Harbin 150046;China Special Equipment Inspection&Research Institute,Beijing 100029)

机构地区：[1]哈尔滨锅炉厂有限责任公司,哈尔滨150046 [2]中国特种设备检测研究院,北京100029

出　　处：《中国特种设备安全》2022年第4期79-81,86,共4页China Special Equipment Safety

摘　　要：某电厂200 MW机组锅炉在通过168 h试运行后,正常运行约7个月,在屏式过热器的下部弯头处发生爆管事故.弯头材质为12Cr1MoVG,公称规格为φ42×5 mm.对失效的屏式过热器管进行宏观分析、化学成分分析、力学性能检验、金相检验和扫描电镜分析,样管的化学成分符合标准要求,力学性能和金相组织不符合标准要求,且爆口附件存在大量的蠕变孔洞.结果表明,发生爆管的原因是屏式过热器长期超温运行,珠光体发生球化分解,导致样管的强度大幅下降,最终发生泄漏爆管.After 168 hours of trial operation,the boiler of a 200 MW unit in a power plant operated normally for about 7 months,and a tube-burst accident occurred at the lower elbow of the platen superheater.The elbow material is 12Cr1MoVG and the nominal specification is Φ 42 ×5 mm.Macroscopic analysis,chemical composition analysis,mechanical property inspection,metallographic inspection and scanning electron microscope analysis were carried out on the failed platen superheater tube.The chemical composition of the sample tube met the standard requirements,the mechanical properties and metal lographic structure did not meet the standard requirements,and there were a large number of creep holes in the explosion mouth accessories.The results show that the reason for tube burst is that the platen superheater operates over temperature for a long time,the pearlite is spheroidized and decomposed,resulting in a significant decrease in the strength of the sample tube,and finally the leakage tube burst.

关 键 词：屏式过热器 蠕变孔洞 珠光体球化 爆管 

分 类 号：X933.2[环境科学与工程—安全科学]