Weld Chemistry and Microhardness Studies of Formulated SrO-CaF2-CaO- SiO2 Silica Based SMAW Electrode with Nickel Wire

The aim of this research is to investigate the impact of weld chemistry and microhardness on the coating flux composed of SrO-CaF2-CaO-SiO2 for Ni-based electrodes used in power plant applications. The electrode flux was produced using the mixture design approach and subsequently extruded onto the IN617 core wire. The use of strontianite and cryolite in the flux composition enhances both the arc's stability and the efficiency of slag removal. We analyzed the weld chemistry, microhardness, and microstructure of the weld by doing multi-pass bead-on-plate studies. Weld beads were deposited using low-alloy steel plate, and their composition was determined by testing for the presence of chromium, cobalt, nickel, iron, and molybdenum. The microhardness value of the deposited welds was determined using a Vicker's microhardness tester. Regression analysis was used to establish a relation between weld chemistry and flux components. It was reported that an increase in SrO in the coating mixture positively influences nickel content from slag to molten pool, whereas calcite has a negative effect. The binary interaction of CaO.CaF2, CaF2.SiO2, and CaO.SiO2 increases chromium transfer. Calcite positively affects nickel content. The binary interaction of CaO.SrO, CaF2.SrO, and SiO2.SrO has shown a significant and increasing effect on the weld metal nickel. The ternary interaction of CaO.CaF2.SiO2, CaO.CaF2.SrO, and CaO.SiO2.SrO has positive effects on molybdenum. SiO2 and SrO has a positive effect on iron content. The binary interaction of CaO.SrO and CaF2.SiO2 has shown a more favorable and increasing effect on the cobalt content. Microhardness increases with an increase in CaF2, whereas CaO has a negative effect on microhardness. Models based on artificial neural networks have been created and compared to the results of regression analysis.