CaO–CaF<inf>2</inf>–SiO<inf>2</inf>–Al<inf>2</inf>O<inf>3</inf> system for development of SMAW electrodes with Ni alloy core wire

This research investigates the effect of CaO–CaF2–SiO2–Al2O3 based flux coating constituents of nickel-based electrodes on the weld chemistry of power plant applications. Extreme vertices design approach was used to prepare electrode coatings and extruded on FM-182 (Nickel based) core wire. TiO2 is added in a fixed amount to enhance the arc stability during welding and slag detachability. Weld beads were deposited on P22 alloy steel plate and examined for weld chemistry in terms of Cr, Ni, Nb and Fe. The microhardness of the deposited welds was also observed using Vicker's microhardness tester. Regression analysis was applied to develop a relationship between the weld chemistry and flux constituents. The results obtained from the regression analysis were then optimized to choose the best suitable electrode coating composition with higher desirability.