蒸汽发生器管子管板焊缝焊接见证件缺陷原因分析及处理

Defect analysis and processing of the tube-to-tube sheet weld test coupon of steam generator

对国内某二代改进型核电机组蒸汽发生器管子管板焊接见证件根部不连续的原因进行分析结果表明,根部不连续超标的根本原因为清洁不彻底,管壁存在杂物影响定位胀效果而导致根部管-孔间隙过大所致,不能代表对应的产品焊缝。根据分析结果提出了相应的防范措施,对后续管子管板焊缝的焊接具有一定的参考和借鉴意义。

The reasons of root discontinuity on the tube-to-tube sheet weld test coupon of the steam generator in a domestic improved second generation nuclear power unit are analyzed. The results show that the tube is not being thoroughly cleaned,so something on the tube wall influence the tacking expanding and lead to a excessive gap between the root tube and hole,which is the ultimate reason of the root discontinuity. So the weld test coupon could not represent the production welds. According to the analysis result,corresponding precautionary measures are proposed,which has some reference for the subsequent welding of the tube-to-tube sheet welds.