Abstract: The support welding block assembly is the key force component in the HL-3 vacuum chamber to connect adjacent sector segments and bear the support. According to the unique structure of hyperboloid and square window assembly, the key points of welding quality and deformation control, machining of hyperboloid and ultra-high vacuum step sealing surface, and welding of supporting welding block assembly with vacuum chamber are analyzed. By designing and manufacturing process equipment, processing three-dimensional curved groove of support block, taking post-welding processing, monitoring deformation during processing and timely adjusting the inner and outer processing processes and other construction process methods and process parameters,the problems of large-thickness welding technology and welding deformation control of the support welding block assembly, the machining technology of the support welding block assembly and the high quality requirement of the ultra-high vacuum step sealing surface, and the technical problems of the support welding block assembly and the vacuum chamber are overcome. Now the HL-3 plasma discharges have been successfully realized, and the related machining and welding technology has been verified.

Key words: HL-3 tokamak, Vacuum vessel, Step sealing surface

摘要： 支撑焊接块组件是中国环流三号(HL-3)装置真空室中连接相邻扇形段并承受支撑的关键受力部件。根据支撑焊接块组件双曲面及方窗口组合体的独特结构，分析了支撑焊接块组件焊接质量与形变控制、双曲面与超高真空台阶密封面机加工及支撑焊接块组件与真空室组焊等关键技术。通过设计制作工艺装备、对支撑块加工成三维曲面坡口、采取焊后加工及加工过程监测形变并及时调整内外侧加工工序等措施，攻克了支撑焊接块组件大厚度组焊技术与焊接形变控制、支撑焊接块组件双曲面与超高真空台阶密封面高质量机加及支撑焊接块组件与真空室组焊等技术难题。目前，HL-3 装置已成功放电，相关机加工及组焊工艺技术得到验证。

关键词: HL-3 托卡马克, 真空室, 台阶密封面