Corrosion behaviors of FeCoNiCr (x = 0, 0.5, 1.0) multi-principal element alloys: Role of Cr-induced segregation

The as-cast microstructures and corrosion behaviors of the FeCoNiCrx (x = 0, 0.5, 1.0) multi-principal element alloys in both 0.5 M sulfuric acid and 3.5% sodium chloride solutions were systematically investigated. With the increased content of Cr, the as-cast microstructure shows a cellular-dendrite transformation due to the Cr-induced segregation. FeCoNiCr0.5 alloy exhibits an outstanding anticorrosion performance in both 0.5 M sulfuric acid and 3.5% sodium chloride solutions, while the excess addition of Cr element leads to the noticeable localized corrosion in FeCoNiCr alloy. The results indicate that the distribution of Cr element plays a non-ignorable role in the anticorrosion performance for FeCoNiCr-based multi-principal element alloy.