Experimental approach to determine the impact of the droplet transfer mode on the degradation of fused tungsten carbides during GMAW

The application of fused tungsten carbides (FTCs) in nickel-based alloys is important for improving the wear resistance of tooling equipment in the mining industry. However, FTCs are thermally unstable and will dilute under excessive energy input during welding. The parameters affecting dilution in this context are diverse and not yet completely understood. To date, the existing scientific literature focuses on the impact of the melt bead characteristics to explain the degradation during gas metal arc welding (GMAW). The degradation-promoting influence of the droplet transfer mode has not yet been considered. A methodology was developed to experimentally quantify the dependence of the degradation kinetics of FTCs on the droplet transfer mode. The established experimental model demonstrated that the globular transfer mode leads to increased degradation of FTCs in comparison to that of the short-arc mode, which can be attributed to the higher process power and hence higher droplet temperature. In this context, the quantifiable impact of the droplet transfer mode was determined. •The amount of fused tungsten carbide (FTC) in gas metal arc welded hardfacings is influenced by the droplet transfer mode.•A methodology was developed to experimentally quantify the dependence of the FTC degradation on the droplet transfer mode.•It has been proven that the globular transfer mode leads to an increased degradation of FTCs compared to the short-arc mode.•40% of the thermally induced FTC degradation was attributed to the change in the droplet transfer mode.