TP347H奥氏体钢屏式再热器爆管失效分析  

Failure Analysis of the Bursting Pipe on TP347H Type Austenitic Stainless Steel Made Platen Reheater

作　　者：孙兴新 Sun Xingxin(Northwest Electric Power Test & Research Institute of China Datang Corporation Science andTechnology Research Institute Co., Ltd., Xi’an 710021, China)

机构地区：[1]中国大唐集团科学技术研究院有限公司西北电力试验研究院,西安710021

出　　处：《发电设备》2021年第3期185-189,共5页Power Equipment

摘　　要：为了研究某电厂循环流化床锅炉屏式再热器TP347H管发生爆管的原因,对屏式再热器失效管样进行爆口宏观分析、化学成分分析、力学性能分析、金相组织观察、X射线衍射分析、扫描电镜分析及能谱分析结果表明:屏式再热器TP347H管发生爆管的主要原因为长时过热。再热器长期运行后,TP347H管局部发生明显的蠕胀现象,壁厚减薄,内壁氧化皮厚度超标,金相组织中存在大量的蠕变孔洞,材料的力学性能下降;同时,组织中存在一次析出相Nb(C,N),且尺寸较大,作为夹杂物随机分布在晶内,使材料的性能进一步劣化。The causes of TP347H tube burst in aplaten reheater of circulating fluidized bed boiler were studied based on the macroscopic analysis,chemical composition analysis,mechanical property analysis,metallographic structure observation,X-ray diffraction analysis,scanning electron microscope analysis and energy dispersive spectrum analysis.Results show that the main cause of TP347H tube burst is due to the long-term overheating.After long-term operation of the reheater,severe high-temperature creep phenomenon occurs in the local part of TP347H tube,the wall thickness is reduced,the thickness of oxide layer on the inner part exceeds the standard,a large number of creep holes in the metallographic structure,and the mechanical properties of the material decrease.At the same time,Nb(C,N)precipitated phase exists in the tissue with large size and is randomly distributed in the grain as inclusions,which further degrades the material performance.

关 键 词：屏式再热器 TP347H 超温 Nb(C N) 爆管 

分 类 号：TG142.15[一般工业技术—材料科学与工程]