电站锅炉水冷壁横向裂纹原因分析

Failure Analysis of Water Wall Transverse Crack

某电厂机组累计运行约70080h,水冷壁内螺纹管向火面外表面发现横向裂纹。本文对表面存在横向裂纹的管子进行宏观检查、壁厚检查、化学成分分析、力学性能试验、光学显微镜检验、裂纹断口形貌扫描电镜检验、裂纹内腐蚀产物能谱分析,对其失效原因进行了分析。结果表明,水冷壁横向裂纹产生的原因是发生腐蚀性热疲劳。

A power plant running around 70080h, plenty of transverse crakes are found on the surface of the water wall fire side. This paper analysis the reasons for the water wall pipe failure with macroscopic and microscopic examination, mechanical property, crack fracture morphology examination by SEM, corrosion products within the crack examination by EDX. The results show that, the transverse crakes on the surface of the water wall fire side caused by corrosive thermal fatigue.