摘要
某电厂的包墙过热器在运行期间发生泄漏,为查明原因,对泄漏管样进行了宏观形貌检查、金相分析、扫描电镜能谱成分分析、硬度试验。试验结果表明:管样的1号、2号及3号试样母材的硬度平均值均高于标准要求的上限值;裂纹断面上有相互平行的清晰的疲劳条纹,裂纹由外壁向内壁扩展。经分析认为管样在鳍片焊缝开裂后向管子母材处扩展,在管子震动、锅炉启停、负荷变化等因素的长期作用下,导致管子母材发生疲劳开裂,直至泄漏。
The enclosure wall superheater of a power plant leaked during operation.In order to find out the reason,the leakage pipe samples were examined by macroscopic morphology,metallographic analysis,scanning electron microscopy energy spectrum analysis and hardness test.The test results show that the average hardness of sample No.1,No.2 and No.3 are higher than the upper limit required by the standard.There are clear fatigue stripes parallel to each other on the crack section,and the crack extends from the outer wall to the inner wall.The analysis shows that the pipe sample expands to the base material of the tube after the fin weld cracks.Under the long-term action of pipe vibration,boiler start and stop,load change and other factors,the base material of the tube was fatigued and cracked until the leakage occurred.
作者
刘佳伟
刘森
张维星
Liu Jiawei;Liu Sen;Zhang Weixing(Shaanxi Hongshun Electric Power Technology Co,LTD.,Xi'an 710054;Xi'an High-tech District Urban Management and Comprehensive Law Enforcement Bureau, Xi'an 710075)
出处
《中国特种设备安全》
2024年第2期88-92,共5页
China Special Equipment Safety
关键词
包墙过热器
泄漏
疲劳开裂
Enclosure wall superheater
Leakage
Fatigue cracking
