核电机组主管道焊缝返修技术及应用

主管道在核电站安全中起着至关重要的作用，主管道焊接质量也显得尤为重要。在目前核电机组主管道焊接中，窄间隙自动焊逐渐取代了传统的手工焊，提高了焊接效率。但由于主管道窄间隙自动焊采用单层单道焊接工艺，如果控制不好，容易出现未熔合等缺陷，影响焊缝质量，必须进行返修。以方家山核电工程2#机组主管道返修过程为例，介绍了一种成功应用于工程实践的主管道手工返修工艺，并归纳总结了主管道自动焊接缺陷类型、产生的原因及返修方法。

Weld Repair Technology and Application of Nuclear Power Unit Main Pipeline

Main pipeline plays an important role in nuclear power plant safety, and main pipeline welding quality also is very important. In main pipeline welding of the current nuclear power units, narrow gap automatic welding gradually replaced the traditional manual welding, which improved the welding efficiency. But it used single-layer single-channel welding process in main pipeline narrow gap automatic welding, if the control is not good, some defects easily appear such as incomplete fusion, affect the weld quality, must be repaired. Taking repair process of Fangjiashan nuclear power project 2# unit main pipeline as example, it introduced a kind of main pipeline manual repair process which successfully used in engineering practice, and summarized welding defects type of main pipeline, causes and repair methods.