对AP1000堆芯补水箱裂纹产生原因的分析

Reason Analysis for Cracking of AP1000 Core Make-up Tank Shell

三门核电站2号机组两台AP1000堆芯补水箱在制造过程中先后发生筒体堆焊层二次下裂纹问题,通过对现场二次UT缺陷分布类比、母材及堆焊层缺陷处材料化学成分分析对比、硬度试验、金相照片和复膜金相照片观察,对堆焊工艺、技术方面的问题进行了分析与研究,初步确定了裂纹产生的根本原因,并提出一些工艺质量控制措施,旨在为避免今后发生类似问题,为提高主设备制造质量提供一些参考与借鉴。

Based on the quality issues about the under-clad cracking for inside surfacing layer of the two AP1000 core make up tank shells for Sanmen 2, analysis and study on the technical process and quality control are carried out according to the analysis and contrast of chemical compositions, comparison of two UT defects distribution, hardness test, metallographic analysis and laminating metallographic observation on site. The root cause of the crack is preliminarily identified, and some technical quality control measures are put forward, with an aim to provide some reference for avoiding similar problems in the future and improving the quality of main equipment manufacturing.