连续行走脉冲TIG焊熔池谐振法熔透控制

熔池振荡频率与熔池尺寸之间的良好对应关系，可以用于进行熔池尺寸检测及熔透控制，但在快速行走焊接时难度很大。本文在恒定直流之上叠加定频率正弦波电流做为脉冲焊接电流激振熔池，在连续行走焊接时，通过电弧电压检测熔池振荡即熔池尺寸。在脉冲电流作用期间，随着熔池尺寸的增长，当熔池自身固有振荡频率与焊接电流正弦波频率一致时，熔池产生谐振，从电弧电压中检测到谐振特征变化信号，该信号的强度，稳定性，重复性及与熔池

Welding Penetration Control with Weld Pool Resonance in Traveling Pulse TIG Welding

There exists excellent corresponding relationship between weld pool oscillation frequency and weld pool size in TIG welding, which can be used to detect weld pool size and control the weld pool penetration. However, It is very difficult during fast travelling welding. In this paper, the weld pool is excited by pulsating welding current which is produced by superimposing a certain frequency sine wave current on the straight polarity DC current, and the oscillating signals of weld pool can be detected through arc voltage signals in travelling TIG welding. During the time when pulsating welding current works, along with the increase of weld pool size, weld pool resonance phenomenon happens when the nature oscillation frequency of the weld pool is equal to the frequency of sine wave current. The feature variant signal of weld pool resonance, detected from arc voltage signal, is better in strength, stability and repeatability than existing method with short pulse high welding current to detect the weld pool oscillation. Moreover, this method has been used for full penetration control in TIG welding and has acquired well effect.