TWI Industrial Member Report Summary 138/1981
By K W Brown
Transverse oscillation of the arc across the joint is commonly employed to spread the heat energy between the parts being welded. Using 25 and 50Hz pulsed MIG arcs in the flat position, the characteristic weld metal shape for mild steel is controllably altered if the transverse motion is correlated with the pulsed metal transfer. Thus, for 1.2mm diameter mild steel electrode at 85-250A mean current and with argon-rich shielding gas, the gun is oscillated at 2½- 6¼Hz pulse-synchronised, at 0.4-12mm amplitude and with 10-170msec dwell period. In this manner the transverse heat distribution and metal deposition can be programmed to provide heat and metal where needed, and the effects of the oscillation parameters are illustrated in bead-on-plate tests with respect to the weld metal shape and bead appearance. Different oscillation modes are described and possible applications are indicated.