自动焊在国际热核聚变试验堆LCTS管组安装中的应用

房云龙 马晓锋 刘丽丽 陈远庭 武海燕

摘要： 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。

关键词： 不锈钢管道; 自动焊; 无损检验

中图分类号： TG 444

Abstract：  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.

Key words：   stainless steel pipe; automatic welding; nondestructive test

0 前言

核聚变能源是未来理想能源，其大规模商业化应用从长远来看可从根本上彻底解决能源问题[1-2]。2020年7月28日，国际热核聚变试验堆（International thermonuclear experimental reactor，ITER）计划正式迈入装配阶段[3-4]。目前，ITER现场正在开展下部杜瓦冷屏（Lower cryostat thermal shield，LCTS）的装配工作，该部件作用是降低高温部件对低温超导磁体的热辐射。LCTS冷屏管组 （Thermal shield manifolds，TSM）将氦气分配到各处镀银面板，以降低冷屏环境温度，是冷屏功能实现的重要途径之一，其焊接和安装质量意义重大[5-6]。

自动焊近年来已经发展为一种较为成熟工业焊接方法，在长输管道、核工业、汽车、制药工业等方面得到了应用[7-10]。该方法通过计算机控制，可以存储各种焊接参数并根据需要随时调用，可以有效保证焊接质量一致性，大幅降低劳动强度，改善焊接作业环境[11-12]。……