A novel sine wave modulation method of pulse current during double wire MIG welding

摘要

As a highly efficient welding method that guarantees good weld quality, double wire pulse welding has broken the neck bottle of single wire welding in terms of weld speed and tackled such problems as undercut and hump during single wire high-speed welding. During double wire welding, double current waveform modulation is a key that affects weld quality and efficiency. Based on single wire sine wave modulation, this paper proposes a new double wire sine wave modulation method. Front and back wire pulse currents with the same peak value and basic current variation amplitude were obtained by performing sine wave modulation on ordinary double current pulse waveform. An in-depth analysis was made in terms of the energy distribution coefficient m, amplitude coefficient k, and the negative half-cycle sine wave pulse number Nn to discuss how double wire sine wave modulation affects weld seam imaging quality. Experimental results show that with the application of sine wave modulation, double wire pulse welding can effectively enhance instantaneous energy density and broaden the energy variation range between pulse current base value and peak value. Also, enhancing weld speed appropriately helps to improve weld quality and efficiency to a great extent.