Microstructural Heterogeneities in Pulsed Gas Metal Arc Welds

The pulsed gas metal arc welding (P-GMAW) process has the inherent advantage of a lower heat input than the conventional gas metal arc welding (GMAW) process while still maintaining the spray transfer mode. This makes it well suited for all position welding as well as for welding thinner sections. During a recent weld procedure development using P-GMAW, it was noted that there were heterogeneities formed in the weld microstructure which were found to have an adverse effect on the mechanical properties of the weld metal. The source of these heterogeneities and their implications on the performance of the welds will be discussed.