Research on the Applicability of Stabilizing Water Treatment Process for Rust Layer of Q500qENH Weathering Steel in Different Typical Environments

The water treatment experiment for rust layer stabilization for Q500qENH weathering steel was carried out in seven different locations for 8 weeks to determine the applicability of the optimal treatment process. Results showed that with the prolonging of the stabilization treatment period, the weight loss and corrosion thinning of the samples increased, the corrosion rate presented a downward trend, and the color of the rust layer on the surface of the samples changed from orange to brown. In addition, the thickness of the rust layer increased gradually. The electrochemical analysis results indicated that the self - corrosion current density of the samples decreased, and the self - corrosion potential gradually shifted positively with the prolonging of the stabilization treatment period. Meanwhile, the results of XRD analysis revealed that the unstable phase (γ - FeOOH) gradually transformed into stable phase (α - FeOOH), and the proportion of stable phase (α - FeOOH) gradually increased with the extension of stabilization treatment period. To sum up the above results, Q500qENH weathering steel was treated by different rust layer stabilization water treatment processes in 3 kinds of typical locations, and a relatively stable rust layer could be obtained after 4～6 weeks.