Study on Arc Behavior and Weld Formation of Magnetically Controlled Narrow Gap TIG Welding

High efficiency and high quality are the developmental trends in modern industry, leading to continuous advancements in research on magnetically controlled narrow gap TIG welding processes. Current research aims to deeply analyze the mechanisms of magnetic fields, with a particular focus on their physical effects on arc behavior. Consequently, the redistribution of arc heat through a magnetic field can be achieved, allowing for precise control of weld formation and quality. In this paper, the arc shape, movement of arc electrons, and weld formation are discussed. A transverse alternating magnetic field was applied, enabling arc electrons to reach the workpiece directly in a "curved knife" trajectory. These electrons can also alter their trajectory through collisions and extrusions, resulting in a larger deflection angle in the arc anode region compared to the cathode region. However, the latter easily causes arc energy loss. Therefore, when the excitation parameters change, the decrease in bottom penetration cannot be completely converted into an increase in sidewall penetration. Appropriately increasing the excitation current can mitigate this effect, reduce energy loss, and achieve good sidewall penetration.