Effect of Exothermic Additions on Heat Generation and Arc Process Efficiency in Flux-Cored Arc Welding

The focus of this research was to determine the effectiveness of exothermically reacting chemical additions to the flux in the Flux-Cored Arc (FCA) welding process. The heat delivery and weldbead morphologies of exothermically assisted FCA welding were experimentally studied with a self-shielded FCA flux formulation. The exothermic additions consisted of stoichiometric mixtures of aluminum, magnesium, and aluminum/magnesium (50/50 wt.%) flux with the mineral hematite systematically displacing iron powder. Exothermic flux additions to FCA welding can assist in the generation of heat and improve arc efficiency. The Al/Mg (50/50) electrodes were significantly more effective than aluminium or magnesium flux additions in composite gain value. The weldment dilution increased with exothermic addition. However, overall dilution with exothermic addition was not higher than baseline value except with a 10 wt.% magnesium addition. Weld deposition was most enhanced by Al/Mg (50/50) additions, showing a greater electrode melting efficiency and a larger weldbead than with magnesium-rich and aluminum-rich additions, respectively.