Effect of different stabilizers on corrosion resistance and damage resistance of Q420qNH weathering steel in industrial atmospheric environment

The stabilization treatment of rust layers on Q420qNH weathering steel was performed using four different stabilizers, followed by exposure to an industrial atmospheric environment. In this study, we investigated the effects of different stabilizers on the corrosion resistance and damage resistance of the rust layer, as well as the formation and evolution of globular products on its surface. All stabilizers increased the initial corrosion rate of the weathering steel. Among the groups, group D exhibited the highest proportion of the alpha-FeOOH phase and the highest alpha/gamma* ratio, as well as the thickest and most compact rust layer (227.84 mu m), characterized by a unique three-layer structure. The self-corrosion current density was the lowest (0.46 mA.cm(-2)), and the low-frequency impedance modulus |Z| was the highest, indicating superior corrosion resistance. Crack propagation resistance was assessed by inducing damage via the indentation quenching method, revealing that damage resistance varied inversely with corrosion resistance. SEM-Raman, SEM-EDS, and XRD analyses were employed to identify the phases of the globular products. Smooth globular products were identified as pure iron particles formed by the localized reduction of Fe2+, which gradually oxidized into various iron oxides while becoming rougher in texture, eventually transforming into stable spherical alpha-FeOOH. Rough globular products represented an intermediate phase between pure iron particles and alpha-FeOOH.