Abstract
Automated weldings (by robot) were carried out in vertical-up position to compare the efficacy of GMAW process with pulsed current against with dip transfer. The complexity for automation and operational requirements is commented and checked, with special emphasis played on bead instability. Both version of the process seems to demand a strict control of the initial arc length to avoid bead misshapen. GMAW-CO2 shows to present a wider tolerance range for parameters selection besides requiring less sophisticated equipment. On the other hand, bead finish is more convex and the penetration rounded. The pulsed version, on the contrary, develops better bead finish and less spatter, yet demanding the use of automatic arc length control.
Referência:
SCOTTI, A. & DUTRA, J.C., Initial Arc Length Adjustments in Robotic Vertical-up GMAW, 76th American Welding Society Annual Meeting, Cleveland, USA, Apr 1995, pp. 96-97