核电厂薄壁不锈钢管道BOSS头焊缝在线维修技术研究  

In-service Repairing Technique Study on BOSS Welds of Thin-walled Stainless Steel Pipes in Nuclear Power Plant

作　　者：匡艳军 KUANG Yanjun(State Key Laboratory ofNuclear Power Safety Monitoring Technology and Equipment,China Nuclear Power Engineering Co,Ltd,Shenzhen 518172 China)

机构地区：[1]中广核工程有限公司核电安全监控技术与装备国家重点实验室,广东深圳518170

出　　处：《电焊机》2022年第11期82-88,共7页Electric Welding Machine

摘　　要：为解决在运核电厂无法隔离的BOSS头焊缝在线修复问题,设计了在不去除原焊缝缺陷情况下的堆焊修复方案,并采用手工钨极氩弧焊工艺对薄壁不锈钢管道上BOSS头焊缝在排空以及带水带压条件下进行堆焊返修,通过理化性能分析、金相检验以及相控阵超声波检验模拟仿真、试验,评价所开发的修复方案、工艺和堆焊层质量。结果表明:设计的堆焊返修方案可行,可在核电厂20 h的窗口期内完成焊接返修,所开发的焊接工艺,通过控制焊接熔深可避免焊接过程中冷却介质的泄漏并获得组织和力学性能满足要求的焊缝,为电厂薄壁管道在线维修提供了一种新的选项,提升电厂的安全性和经济性。In order to repair the BOSS welds which can not be isolated even shutting down the operating nuclear power plant, a overlay repair scheme with pre-existed defects not been removed was proposed, which was carried out using manual GTAW procedure for BOSS welds on thin-walled stainless steel pipes with and without coolant and pressure inside. The scheme, procedure and the quality of the repair welds was evaluated by mechanical properties tests, micro and macro examination, simulation and verified test of phased array ultrasonic examination. Results shows that the proposed repairing scheme is feasible, which can be completed in the 20 hours limited time windows of the plant, the leaking risk of the coolant can be avoid by controlling the welding fusion depth with the specific welding procedure developed, and the microstructure and mechanical properties of the welds can be satisfied. Then a new selection could be in place for the in-service repairing of the thin-walled pipe to guarantee the safety and the economy of the nuclear power plant.

关 键 词：核电厂 薄壁不锈钢 BOSS头焊缝 在线维修 

分 类 号：TG457[金属学及工艺—焊接]