微束等离子弧电源外特性的研究

ON THE POWER SOURCE FOR MICRO-PLASMA ARC WELDING

关键词:  微弧等离子焊  焊接电弧  直流弧焊电流

Key words:  Micro-plasma arc welding  Welding arc  DC arc welding power sourse

摘要:

本文通过对微束等离子电弧形态的分析,弧长波动对焊缝宽度比、电弧电流分散度的影响等测试,提出,在弧长波动时,工件有效热功率变化的原因,主要是电弧存在着电流分散现象。在纯氩气氛中,垂降外特性和双曲线外特性两种电源,都不能在弧长波动时保持工件有效热功率不变。当电弧受到足够的双原子气氛冷却和压缩时,双曲线外特性电源的优越性才得显示出来。文章最后指出,在纯氩气氛中,微束等离子弧最佳电源外特性应该是上升型的。

Abstract:

Through testing the shape of micro-plasma arc,the dispersion of arc current and the ratio of weld width against the fluctuation of arc length, the authors put forward that neither the constant-current power source nor the hyperbolic charscierislic power source could make the heat input to the anode (workpiece) constant under the fluctuation of arc length. Only when the arc is intensely constricted by the mixed gas, the power source with hyperbolic external characteristics would then be slightly better. The main cause of the variation in the heat input with arc length is that the arc itself has current dispersion. This paper provides a theoretical basis for developing the optimum power source for micro plasma arc welding.