某电厂高温再热器入口集箱筒身环缝裂纹分析及处理

Analysis and treatment of cracks in annular welds of inlet header of high temperature reheater in a power plant

针对某电厂投运锅炉机组高温再热器入口集箱筒身裂纹,对裂纹宏观形貌进行了观察,对裂纹区域焊缝和母材的金相、硬度进行了检测,以及对集箱制造过程进行了研究。以最小程度破坏集箱的方式,分析了集箱筒身环缝横向裂纹的产生原因,并提出了裂纹处理方案。结果表明,制造过程中集箱筒身表面划伤,补焊操作不当导致冷裂纹产生,并在锅炉运行中扩展,形成宏观裂纹。

Based on the macroscopic morphology of the cracks,the metallographic and hardness inspection of the welds and the base metal in the nearby area of cracks,and the manufacturing process of the headers were studied.The causes of the transverse cracks in the annular welds of the headers were analyzed,in the form of minimal destruction of the header.The results showed that the surface of the header cylinder was scratched during the manufacturing process,and the improper repair welding operation led to the cold cracks,and it was propagated in the boiler working to form the macroscopic cracks.