Effects of Shielding Gas Composition on Process Stability and Arc Behavior of Laser-Cable-Type Welding Wire Arc Hybrid Welding

This study systematically investigates the behavior of droplet transfer and the characteristics of weld morphology in laser-cable-type welding wire (CWW) arc hybrid welding under varying Ar-CO2 shielding gas compositions, utilizing AH36 shipbuilding steel. During the hybrid welding process, a comparative analysis was conducted on the welding process and weld formation using a high-speed camera system and a current–voltage waveform acquisition system. The experimental findings indicated that the arc width exhibited an upward trend, while the arc height demonstrated a decline as the CO2 content increased. Additionally, the welding current experienced a decrease. Furthermore, the arc became more regular with an increase in the top arc width, which enhanced process stability. The peak intensity of the curve for 90% Ar + 10% CO2 was the largest, and the peak range was the narrowest, indicating that the current was more stable compared to the other two shielding gas compositions. The droplet transfer frequency exhibited a decreasing trend with the increase in CO2, while the diameter initially decreased and then increased. As the CO2 content increased, the droplet transfer mode transitioned from a mixed mode involving both globular transfer and short circuits to predominantly globular transfer. The increase in CO2 promoted weld penetration while reducing its width, with the penetration depth of the weld increasing by 12.3% when the CO2 content rose to 18%.