旁路耦合微束等离子弧热特性及焊缝成形特点

针对传统微束等离子弧焊中焊丝熔敷率与焊接电流不能解耦的局限，提出旁路耦合微束等离子弧焊方法.通过给外填焊丝添加一电流，使焊丝与焊枪钨极间产生一个旁路电弧，实现熔化母材热量与熔化焊丝热量的解耦，确保熔化母材电流稳定的同时提高填充焊丝的熔化速度.对旁路耦合微束等离子弧焊的熔敷率、母材热输入及焊缝成形质量进行试验研究.结果表明，该方法既保持了传统微束等离子弧焊的优点，又在提高焊丝熔敷率的同时降低母材的热输入；并在其它焊接参数保持不变时，随旁路电流的增加，焊缝的熔宽、熔深和稀释率减小，余高和成形系数增大.

Thermal characteristics and weld formation of double-electrode micro-plasma arc welding

To solve the limitation about deposition rate and welding current can not be decoupled of the traditional micro-plasma arc welding, double-electrode micro plasma arc welding is proposed.The article added a bypass current into the filler wire to make a bypass arc is appeared between the wire and the tungsten. Though this method to realize the decoupling of the heat of melting base material and the heat of melting wire. Thus, the melting speed of the filler wire is increased while the current of melting base material keeps stable.The experimental study was carried out on the deposition rate, the heat input of the base metal and the weld formation quality of the double-electrode micro plasma arc welding. The double-electrode micro plasma arc welding not only maintains the advantages of the conventional micro plasma arc welding, but also improves the deposition rate and reduces the heat input of the base metal; When the other welding parameters remain unchanged, the weld penetration and dilution rate decrease and the forming coefficient increases with the increase of the bypass current.