Research on the “jump sidewall” behavior and its signal characteristics in narrow gap P-MAG welding

Arc “jump sidewall” phenomenon is observed during P-MAG welding in narrow gap conditions. The mechanism and formation conditions are analyzed, and the phenomenon is found to be the arc channel re-establishment process, which results from large changes in the welding current. The arc channel position is the result of the balance between the electric field force and the magnetic field force. The current characteristics of P-MAG welding in a narrow groove provide adequate conditions for a “jump sidewall” phenomenon. The influences of a narrow gap groove on droplet transfer and arc signal of P-MAG power supply with modified I-I external characteristics are discussed. The research results lay a foundation for arc sensor-based welding seam tracking technology in narrow gap P-MAG welding.