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本文研究了脉冲电流波形对氩弧焊熔滴过渡的影响。曾采用三角形波、矩形波、带前沿冲刺的矩形波、梯形波和半波正弦波等波形进行试验,研究了脉冲冲量、前沿陡度、脉冲峰值及其所在相位对熔滴过渡的影响。通过工艺试验和对带有同步记录焊接电流波形的高速摄影照片的分析发现:(1)钢焊丝脉冲焊的熔滴过渡不仅与脉冲冲量的大小,而且与脉冲的波形形状尤其是与峰值的大小与相位有关,即用Daggett E. H. 的“等冲量原理”来判断各种波形下的熔滴过渡是不合适的;在相同脉冲冲量下,脉冲前沿较陡、脉冲峰值较大、脉冲时间较短的波形,与脉冲前沿平坦、脉冲峰值较小、脉冲时间较长的波形相比,能保证更稳定的熔滴过渡。(2)铝合金的脉冲熔滴过渡的试验进一步证实了上述结论,同时还发现在脉冲峰值较小,脉冲时间较长的情况下,如果脉冲冲量选择不当,会出现第二滴的慢速飞渡现象;用峰值较大而宽度较小的脉冲可以较方便地避免上述现象。
In this paper, the influence of pulse current waveform on the flux-drop transition of argon arc welding was studied. Triangular wave, rectangular wave, rectangular wave with front sprint, trapezoidal wave and half-wave sine wave were used to study the effects of impulse, frontier steepness, pulse peak and phase on droplet transfer. Through the process experiment and the analysis of high-speed photogrammetry with synchronous recording of welding current waveforms, it is found that: (1) The droplet transfer in steel wire welding is not only related to the pulse impulse but also to the waveform shape of the pulse, especially the peak With the phase, that is to use Daggett EH “equal impulse principle” to determine the droplet transfer under various waveforms is not appropriate; the same pulse impulse, the pulse frontier steep, the pulse peak is larger, the pulse time is shorter Waveform, compared with the waveform of the pulse front is flat, the pulse peak is small, the pulse time is longer, to ensure a more stable droplet transition. (2) The experiment of pulsed droplet transfer of aluminum alloy further confirms the above conclusion, and at the same time also finds that if the impulse peak is small and the pulse time is long, if the pulse impulse is improperly selected, the second drop slow fly Crossing phenomenon; with larger peak and smaller pulse width can be more easily avoid the above phenomenon.