核电厂水下TIG焊炬设计及焊接工艺研究  

Design of Underwater TIG Welding Torch and Study on Welding Technology for Nuclear Power Plant

作　　者：周国丰 张清华 张红 孙清洁 王晓磊 ZHOU Guofeng;ZHANG Qinghua;ZHANG Hong;SUN Qingjie;WANG Xiaolei(China Nuclear Power Research Institute Co.,Ltd.,Shenzhen 518000,China;Provincial Key Laboratory of Special Welding Technology,Harbin Institute of Technology,Weihai 264209,China)

机构地区：[1]中广核研究院有限公司,广东深圳518000 [2]哈尔滨工业大学(威海)特种焊接技术省重点实验室,山东威海264209

出　　处：《电焊机》2023年第11期16-22,共7页Electric Welding Machine

摘　　要：针对核电厂水下定位销的更换及安装,为了得到高质高效的自动化焊接方法,通过自行设计的局部干法水下TIG焊枪在水中对控氮不锈钢管板结构进行焊接。首先对局部干法水下TIG焊炬进行结构设计,并采用ANSYS进行焊炬的流体仿真模拟,优化进气口位置、进气方式等并验证其排水效果,研究了焊接工艺参数对水下TIG焊缝成形的影响规律,并对水下TIG焊接焊缝的力学性能进行了测试。结果表明,经过优化,此焊炬在水下焊接时通气3 s后便可得到稳定的局部干燥空间,避免了水环境对焊接过程的干扰。使用此焊枪可以在水下得到均匀连续的焊缝,且焊缝横截面参数随焊接工艺参数变化的规律与陆上焊接相同,但是熔深和熔宽均比陆上焊接的小;同时发现水下焊缝的熔深、熔宽的变化可能是由于水下冷却速度快和低温环境对电弧的热压缩交替作用引起的;焊缝的力学性能与焊接电流成正比,与焊接速度成反比。水下TIG焊接焊缝的力学性能与陆上焊接得到的焊缝相当,甚至略高。This paper aims to develop high-quality and efficient automatic welding methods for the replacement and installa‐tion of underwater positioning pins in nuclear power plants.To achieve this,a self-designed local dry underwater TIG weld‐ing gun is used to weld the nitrogen-controlled stainless steel tube sheet structure underwater and achieve the desired weld quality.Firstly,designs the structure of the local dry underwater TIG welding torch.Fluid simulation of the welding torch is then performed using ANSYS to optimize the position and mode of the air inlet and verify the drainage effect.The study also investigates the influence of welding process parameters on the formation of underwater TIG weld and tests the me‐chanical properties of the weld.The results show that after optimization,the welding torch can establish a stable local dry space during underwater welding,eliminating interference from the water environment.Using this welding gun,a uniform and continuous weld can be achieved underwater.The variation of cross-section parameters of the weld with welding pro‐cess parameters is similar to that of onshore welding,but the penetration depth and width are smaller.It is also found that the change in penetration and width of the underwater weld may be attributed to the rapid cooling rate of water and the alternat‐ing effect of thermal compression of the arc in a low-temperature environment.Furthermore,the mechanical properties of the weld are directly proportional to the welding current and inversely proportional to the welding speed.The mechanical prop‐erties of the underwater TIG weld are equivalent to or even slightly higher than those of onshore welds.

关 键 词：水下焊接 局部干法 焊炬设计 工艺研究 力学性能 

分 类 号：TG456.5[金属学及工艺—焊接]