压水堆核电站主回路管道窄间隙自动焊工艺研究

Research on narrow-gap GTA welding of PWR nuclear power plant primary piping

压水堆核电站主回路管道是超低碳奥氏体不锈钢大厚壁管道,在高温、高辐射的环境下服役,对焊接质量要求非常高。我国目前核电站主回路管道焊接采用宽坡口焊条电弧焊工艺,焊接一道焊口需要两名高级焊工焊接一个月,焊接周期长、效率低、劳动强度高。为了缩短焊接时间,提高焊接质量和效率,核工业工程研究设计有限公司通过引进先进的焊接设备,开展了一系列焊接工艺试验,确定了窄间隙坡口型式和与之配套的焊接工艺参数,并按照RCC-M标准进行了焊接工艺评定,评定结果全部符合标准要求。因此,压水堆核电站主回路管道采用窄间隙自动焊工艺是可行的,且具有显著优势。

PWR primary piping is a large thick-walled ultra-low carbon austenitic stainless steel pipe,working under high temperature and radiation environment,so high welding quality is required.Currently,China＇s nuclear power plant primary pipe welding is implemented through SMAW-welding process with wide groove,and to finish a weld usually need two senior welder weld more than one month.So the welding cycle is long,inefficiency and needed high labor intensity.To shorten the welding cycle and improve the welding quality and efficiency.An advanced welding equipment introduced by Nuclear Industry Engineering Research and Design Co.,Ltd.,after a series welding process tests,we determined the narrow gap groove patterns and the corresponding welding parameters.And in accordance with the RCC-M standard,we carried out the welding procedure qualification,and all the evaluation results meet the standards.Therefore,using narrow gap welding process in the primary piping of PWR nuclear power plant is feasible and has a significant advantage than hand-welding process.