| Abstract Scope |
Controlling weld penetration in Gas Tungsten Arc Welding (GTAW) is especially critical when
working with materials of differing thermal properties. This work investigates the effect of
electrode rotation on weld pool behavior using a custom-built electrode-spinning GTA welding
gun, with the ultimate goal of improving weld symmetry in dissimilar alloy joints. Experimental
tests were performed on 2"×2"×1/4" plates of 1018 low-carbon steel and 304 stainless steel
under stationary welding conditions at 125 A, with electrode rotation speeds of 0, 300, and 600
RPM. These tests were designed to validate previously developed transient heat transfer
simulations conducted in COMSOL Multiphysics.
Cross-sectional images of the resulting welds reveal a clear relationship between electrode
rotation speed and penetration characteristics. As the RPM increased to 300, arc distribution
became more uniform and weld penetration more centralized in the 304 and in 1018 steel
improved thermal distribution, arc stability and depth of penetration, particularly at 600 RPM.
These observations align well with simulation predictions, confirming the efficacy of electrode
spinning in enhancing weld pool control.
This study proposes a future extension: applying electrode-spinning GTAW to the welding of
dissimilar alloys. Given the differing thermal conductivities and melting behaviors of these
materials, standard GTAW often produces uneven welds with excessive penetration in one alloy
and insufficient fusion in the other. By using a spinning electrode to promote thermal symmetry,
we aim to reduce this disparity and improve the weld quality across the joint. The experimental
results presented here lay the foundation for this next step, offering a promising path forward in
dissimilar metal welding. |