Canopy密封焊缝切割重焊工艺

Cutting and rewelding process of Canopy seal weld

针对三代核电反应堆压力容器驱动结构密封焊缝Canopy焊缝返修的问题,文中采用将失效焊缝切割后重新焊接的方式进行返修。文中对Canopy焊缝切割后重新焊接的返修工艺进行了研究,从切割至重新焊接工艺过程进行论述,并对重新焊接后的焊缝进行无损检验和微观组织分析。同时将重新焊接的焊接接头与采用相同的工艺仅经历一次焊接的焊接接头进行对比,从接头宏观结构、微观组织进行对比分析,从而对重新焊接的焊接接头的质量进行评价。试验结果表明,通过控制焊缝切割质量并对切割后的坡口进行修磨,可以采用原工艺进行焊缝的重新焊接,且重新焊接的焊缝无损检测合格,接头微观组织不存在有害的析出物,焊缝质量与仅进行一次焊接的焊缝质量相当,证明将失效的焊缝切割后重新焊接的方案可以用于Canopy焊缝的返修。

In view of the problem of repairing Canopy sealing weld of drive structure of the pressure vessel in the third generation nuclear power reactor,the failed weld was cut and rewelded for repair in the paper.The repair process of Canopy weld after cutting and rewelding was studied,and the process from cutting to rewelding was discussed,as well as non-destructive testing and microstructure analysis of the rewelded weld.At the same time,the rewelded joint was compared with the welded joint that only underwent one welding with the same process,and the macrostructure and microstructure of the joint were compared and analyzed,so as to evaluate the quality of the rewelded joint.The test results showed that through controlling cutting quality of the weld and grinding the groove after cutting,the weld could be rewelded under the original process,and the rewelded weld passed the nondestructive testing.There were no harmful precipitates in the microstructure of the joint,and the weld quality was equivalent to that underwent only one welding.It was proved that the scheme of rewelding the failed welds after cutting could be used for the repair of Canopy welds.