海阳AP1000核电工程安全壳电气贯穿件焊缝缺陷分析

海阳AP1000核电工程安全壳电气贯穿件套筒与补强板焊缝,焊接完成后经UT检验,发现存在大量危险性Ⅰ类缺陷,主要为裂纹、未融合、条渣、气孔等类型.通过统计分析,焊接缺陷主要集中在内侧焊缝套筒母材侧融合区,偏向于仰焊位置.本文主要从焊接工艺、施工作业条件等方面对缺陷产生的原因进行分析,得出通过对焊材选用、焊前预热方式、坡口设计、焊接工艺、电气贯穿件安装次序等方面的改进,可以很好的改善电气贯穿件焊接质量,这对后期核电建设具有一定的借鉴意义.

Analysis on the Welding Defects of the Containment EPA in HaiYang AP1000 NPP

Plenty of harmful defects were found at the weld of the electrical penetration sleeves and the reinforce plates of the containment EPA in HaiYang API000 NPP by UT examination, such as flaws, incomplete fusion, slag inclusion, gas pore etc. The defects located mainly at the inner side of the base material. The defect causes were analyzed from the aspect of welding process and operating conditions. Some measures, which improved the welding quality of EPA, were put forward in flux selection, preheat method, groove type, welding process, and assembling sequence.