外加纵向磁场作用下的TIG焊接电弧

Arc shapes of TIG welding in a longitudinal magnetic field

摘要: 以单粒子理论假设为基础,详细阐述了外加纵向磁场在等离子体中的不均匀分布形态,以及这种不均匀磁场对TIG焊接电弧形状的影响,分析了电弧区的受力情况,建立了等离子体中带电粒子在这种非均匀磁场中的运动方程.由分析可知带电粒子在磁场作用下的运动轨迹是一条汇聚的螺旋线,且等离子弧外围的带电粒子的圆周运动的速度远大于弧柱中心的粒子运动速度.结果表明,在外加纵向磁场的作用下,TIG焊电弧发生了明显的收缩,激磁电流一定,激磁频率越高,电弧收缩越明显.

Abstract: The unequal distribution of longitudinal magnetic field in plasma and its influence on the arc shape of TIG are discussed in detail based on single-particle theory.The arc force with the longitudinal magnetic field is analyzed,and the motion equation of the charged particle in plasma with the unequal distribution of the longitudinal magnetic field is established.The path of the particle in the magnetic field is a convergence helix.The circular motion speed of particles in the external of plasma arc is much more than that in the column central of the arc.The experiments show that TIG arc is compressed obviously under magnetic field,and when exciting current is constant,the higher the magnetic frequency is,the more severely the arc is condensed.