自动焊在国际热核聚变试验堆LCTS管组安装中的应用

Application of automatic welding technology in manifolds of LCTS on ITER site

为了满足现场下部杜瓦冷屏管组焊接要求,针对规格为∅60.3 mm×2.77 mm和∅73 mm×3.05 mm奥氏体不锈钢管道开发了2种焊接工艺。工艺评定的无损及理化检验结果显示,焊接工艺能够满足ASME及欧盟压力容器标准的要求。结合模拟试验,从开发的工艺中选用了开放式机头自熔式焊接方法,并加以适应性改进,满足了产品同材质管道焊接需求。引入预制概念,在地面上焊接距离冷屏仅有51 mm的管道焊缝,后在冷屏板上合环焊接,解决了焊接空间狭小问题。通过对管道水平度、坡口准备、充氩时间、充氩压力等环节进行严格控制,现场自动焊无损检验一次合格率达98.5%,自动焊技术在冷屏管组安装中得到成功应用。

In order to meet the welding requirements of Thermal Shield Manifolds,two welding processes were developed for austenitic stainless steel pipes with sizes of∅60.3 mm×2.77 mm and∅73 mm×3.05 mm.The non-destructive and physical and chemical testing results of the process evaluation showed that the welding process parameters met the requirements of ASME and EU Pressure Equipment Directive.Considering the simulation tests,the open welding head with self-melting welding method was selected from the developed process,and adaptively improved to meet the requirements of production pipeline welding.The concept of prefabrication was introduced,and the distance from the thermal shield to the pipeline weld was only 51 mm on the ground,and then the ring was closed on the cold screen plate to solve the problem of small welding space.By strictly controlling the levelness,welding groove,argon filling time and argon filling pressure,the first pass rate of the nondestructive inspection for automatic welding reached 98.5%,and the automatic welding technology was successfully applied in the installation.