Research on low-spatter short-circuit transfer waveform and modeling method based on fast-frequency pulse current

Aiming at the problem that it is difficult to balance low spatter control and arc modulation during the arcing phase in short-circuit transfer, a Fast-Frequency Pulsed (FFP) current-assisted low-spatter short-circuit transfer waveform was proposed in this paper. This waveform adopts segmented current control in the short-circuit stage, and only superimposes 5–40 kHz pulsed current in the high-current arcing stage. A coupled integrated Simulink model integrating the FFP welding power supply and the dynamic process of short-circuit transfer is established. An objective function based on current, voltage and transfer period errors is constructed to calibrate the parameters of the model, an experimental matrix is determined. Finally, an experimental prototype is developed. Simulation and experimental results under independent working conditions show that, with 1.2 mm ER50–6 welding wire and Q235B surfacing welding process, the proposed model can accurately predict the characteristics of the proposed waveform, with the errors of average current and average voltage not exceeding 1% and 5.8% respectively. Compared with the traditional CV short-circuit transfer mode, under the same average current, the FFP mode increases the transfer frequency from 54 Hz to 105 Hz, reduces the spatter rate from 4.9% to 0.8%, and increases the weld penetration by 7.8%. The research conclusions are limited to the adopted FFP welding power supply architecture and the 5–40 kHz FFP parameter range.