引弧过程的物理特征

Physical characteristics of striking arc

利用光谱诊断系统对TIG焊接触引弧阶段进行了观测.发现了该过程中存在着贡献电子的主体电离元素的变换现象.在引弧初始阶段,金属元素是电子的主要贡献者,而后则以保护气体元素激发提供电子为主.文中应用Hα谱线的Stark展宽计算了引弧阶段的电子密度,并通过对引弧过程这一可重复弛豫现象的讨论,分析了该过程的统计规律性.文中同时进行了激光辅助引弧和MIG焊引弧的对比试验,观察到引弧过程中亦存在着类似前述的规律.结果表明,焊接引弧的这一物理特征具有认识上的普遍适用性.

The striking arc of TIG touch was observed through the spectral diagnosis system.The changing phenomenon of main ionized element that provided the electrons in striking arc was found.The metallic element was the main contributor to provide the electrons at the beginning of the discharging,and then the excited shielding gas element replaced the metallic element.The electron density during the period of the arc starting was calculated by the Stark-broadened line of Hα.Through the discussion with the repeatability in relaxation phenomenon,the statistical regularity in the arc starting process was analyzed.The similar rules as above were observed via the comparison with the laser-assisted arc starting experiments and the MIG arc starting experiments.It laid the basis for further establishing the physical modeling in different stages of the striking arc and exploration for the new modes of welding arc starting.