Effect of arc swing parameters on narrow gap vertical GMA weld formation

Abstract

Arc force impulse and mean arc linear energy, and the own ratios of them in the scanning course to those at the staying phase, were proposed to analyze swing arc dynamic and welding energy features for narrow gap vertical GMA process. Actual effect and influencing mechanism of swing parameters on solid and flux-cored wire arc weld formations were then investigated. Experimental results show that sidewall penetration, bottom twin peaks and transitional fillet weld grow with increasing swing frequency and staying time and decreasing arc-sidewall distance, and flux-cored wire arc weld metal surface is generally concave while solid wire one likely goes convex. Furthermore, long arc-sidewall distance, and the too great and excessively low values of swing frequency and staying time, readily cause weld pool to sag. It is also demonstrated that arc force impulse ratio and arc linear energy into groove middle jointly dominate weld pool sagging, while arc linear energy ratio determines bottom bead formation.