摘要
通过宏观分析、显微组织观察、力学性能测试、硬度测试以及能谱成分分析,对某热电厂余热锅炉20G疏水管爆管原因进行了分析。结果表明:爆口管件存在明显胀粗;爆口附近珠光体已经完全球化,并且存在轻度石墨化现象,表明该管件长期超温;管件的室温拉伸性能略低于标准要求的下限值,说明材质性能下降。结合疏水管现场空间结构推断,疏水管隔仓与受热面烟气通道之间缺乏有效的密封,存在高温烟气向隔仓内流动,导致疏水管局部因长期超温而爆管。
The failure analysis of 20G steel drain pipe in heat recovery at a thermal power plant was investigated by means of macro analysis, metallographic analysis, mechanical performance testing, hardness measurement and EDS analysis.The results show that the failure pipe is swelled;the complete spheroidization of pearlite with light graphitization appears at the burst area, which indicates long-term overtemperature problem existed for this pipe. The strength of pipe does not meet the lower limit of standard, which indicates the strengh decreases. Considering the structure of the drain pipe in boiler, this long-term overtemperature burst is caused by high temperature flue gas because of the lace of effective seal between gas passage and drain pipe system.
作者
陈鑫
董树青
杜双明
张坤
CHEN Xin;DONG Shuqing;DU Shuangmin;ZHANG Kun(Thermal Power Technology Research Institute,China Datang Corporation Science and Technology Research Institute Co.,Ltd.,Beijing 100040,China)
出处
《热加工工艺》
北大核心
2021年第10期160-162,共3页
Hot Working Technology
关键词
20G钢
锅炉疏水管
超温
珠光体球化
失效分析
20G steel
drain pipe of heat recovery boiler
overtemperature
spheroidization of pearlite
failure analysis
