在保证焊接热输入不变情况下，利用同时改变强弱脉冲个数的方法实现双脉冲低频的调频，并基于直接的电信号波形、间接的焊缝宏观和微观金相对三组不同频率双脉冲和一组单脉冲进行焊缝质量比较.结果表明，双脉冲对熔池的搅拌作用使得焊缝质量优于单脉冲，同时随着双脉冲低频频率的变化，在调制频率3.8 Hz时接近熔池振荡频率，使振荡加强，焊缝热影响区减小，晶粒组织细化，焊接性能最好.
In order to keep the welding heat input constant, number of strong and weak pulse has been changed concurrently to achieve double pulse low-frequency modulation. Based on the directly welding electrical signal waveform, indirect macro and micro metallographic, three different frequency of double pulse and one single pulse weld were compared. The results show that the stirring effect of double pulse on molten pool made the weld better than that of the single pulse. With the changing of double pulse low-frequency, the modulating frequency of 3.8 Hz was close to the weld pool oscillation frequency, by which weld pool oscillation was strengthened. The weld heat affected zone decreased, weld grain refined, and welding performance was the best.
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