锅炉高温再热器长时服役TP310HCbN钢管失效分析  

Failure Analysis on TP310HCbN Steel Tube of Boiler HighTemperature Reheater with Long Term Service

作　　者：宋玉 廖永浩 于鑫 聂海军 杨林 Song Yu;Liao Yonghao;Yu Xin;Nie Haijun;Yang Lin(Huadian Electric Power Research Institute Co.,Ltd.,Hangzhou 310012,China)

机构地区：[1]华电电力科学研究院有限公司,杭州310012

出　　处：《发电设备》2024年第3期172-176,共5页Power Equipment

摘　　要：针对某660 MW超超临界机组服役4.6万h后的锅炉高温再热器,通过金相检测、扫描电镜、拉伸试验和冲击试验等方法对泄漏的TP310HCbN钢管的组织形貌和力学性能进行研究。结果表明:长时高温服役使TP310HCbN钢管的金相组织老化至3~4级,晶界析出大量碳化物,管材严重脆化,导致其韧性储备不足,受外力撞击后外壁表面形成大量微裂纹,随着服役时间的延长,管样裂纹逐渐扩展并最终导致爆管泄漏。For a boiler high temperature reheater with long term service after 46 000 hours in a 660 MW ultra-supercritical unit, researches were conducted on the microstructure and mechanical properties of the leaked TP310HCbN steel tube by means of metallography test, scanning electron microscopy, tensile property test and impact property test. Results show that, the aging grade of the leaked TP310HCbN steel tube microstructure after long term service at high temperature is 3-4, and the tube material presents a serious embrittlement property with a large mount of carbide precipitating at the grain boundary, which result in the insufficient toughness of the tube material. A large number of micro-cracks are formed on the surface of outer tube by impacting, after which, the tube cracks gradually expand and eventually lead to leakage with the increase of service time.

关 键 词：锅炉 高温再热器 奥氏体耐热钢 TP310HCbN 时效脆化 

分 类 号：TM621.25[电气工程—电力系统及自动化] TG142.7[一般工业技术—材料科学与工程]