Effects of CaO–ZrO2–SiO2–CaF2–TiO2-based electrode coating components on weld chemistry and microhardness

This article investigates the influence of CaO–ZrO2–SiO2–CaF2–TiO2-based electrode coating components on the weld metal chemistry in marine structures. Coating formulations were developed using a mixture design method and applied to an austenitic ER 2209 filler wire. The study focuses on analysing the chemical composition of multi-pass weld beads produced from duplex 2205-grade steel. Microhardness measurements were conducted using a Vicker's microhardness tester, and regression analysis was employed to assess the interactions between coating components, weld chemistry, and microhardness. Metallographic examinations were performed using optical and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The findings reveal that different coating minerals affect both the weld's microhardness and chemical composition. Flux elements and binary combinations reduce carbon content, while the calcite.zirconia.silica ternary combination increases it. Manganese levels tend to increase with binary combinations but decrease when ternary combinations are used. All components contribute to an increase in microhardness except calcite.