氦气保护超低真空电子束焊接束流散射及焊缝形貌分析

Analysis of beam scattering and weld morphology in helium protected by ultra-low vacuum electron beam welding

为了解决低真空和局部真空电子束焊接时,电子束严重散射而引起的熔深、熔宽降低和焊接过程不稳定的问题,文中研究了加速电压为100 kV,束流为60 mA,真空度在133.32～1 333.2 Pa变化时的电子束和焊缝形貌的变化规律,并提出了同轴氦气保护的焊接工艺方法.结果表明,在进行低碳钢材料的焊接时,整个工艺过程稳定,得到了焊缝熔深为30～40 mm,大深宽比的电子束焊接接头.

In order to solve the problems of melting depth and melting width reduction, and unstable welding process caused by severe scattering of electron beam in low vacuum and local vacuum electron beam welding. The variation of electron beam and weld morphology with the acceleration voltage of 100 kV, beam current of 60 mA and vacuum of 133.32 ~ 1 333.2 Pa was studied. A coaxial helium shielded welding process is proposed. During the welding of low carbon steel, the whole process is stable. The weld penetration is 30 ~ 40 mm, and the electron beam welding joint with large aspect ratio is obtained.