Corrosion Resistance Behavior of a New Type of Weathering Steel in Simulated Environments with Different pH Values

In this work, the corrosion resistance of weathering steel (WS) containing chromium (0.41 wt%), copper (0.27 wt%), and nickel (0.13 wt%) was investigated in simulated acidic (pH = 4), neutral (pH = 7), and alkaline (pH = 10) environments. The addition of Cr plays a major role in the corrosion resistance of the studied WS. The formation of FeCr2O4, Cr(OH)3, and Cr2O3 in the rust layer enhances its densification and stability. The effectiveness of Cu and Ni in enhancing corrosion resistance is constrained due to their incorporation in minimal quantities. The electrochemical analysis results indicate that WS exhibits the highest corrosion resistance in alkaline environments, followed by neutral conditions. The comparatively lower corrosion resistance in acidic environments is attributed to the penetration of H+ ions into the rust layer, which inhibits the formation of α-FeOOH and contributes to the partial exfoliation of the rust layer.