Effect of Different AC Densities on Corrosion Resistance and Mechanism of FeCoNi HEA in Simulated Golmud Soil Environment

The paper systematically studied the effect of AC density on corrosion resistance of FeCoNi HEA in simulated Golmud soil solution. The results imply that the applied i_AC seriously decreases the anticorrosion property of the HEA. In particular, under high AC density, the active state is presented and the corrosion characteristic changes from slightly local pitting to uneven overall corrosion with massive large-sized corrosion pits. Moreover, after imposed AC of 100 A/m², the honeycomb holes are produced within passive film, which suggests that AC severely damages the film integrity, and reduces the protection and stability of the film. This phenomenon is due to the reason that as i_AC rises, more generated hydrogen ions/atoms and Cl⁻ are absorbed on the defect regions of passive film, significantly promoting the film dissolution, and facilitating the pitting initiation and development.