Effect of Sulfate-Based Stabilizers on the Rust Layer Formation and Corrosion Resistance of Q420qNH Weathering Steel

Abstract

This study investigated the use of sulfate-based stabilizers to stabilize the surface of Q420qNH weathering steel (WS) and their effect on rust layer formation and corrosion resistance. Dry/wet cyclic corrosion tests (CCT) were used to examine the effects of the various treatment regimens. The results demonstrated that sulfate-based stabilizers accelerated the formation of α-FeOOH, thereby enhancing the corrosion resistance of WS in simulated marine atmospheres. Particularly, the A1 stabilizer consisting of the CuSO₄, FeSO₄, NaHSO₃, and Cr₂(SO₄)₃ solution system shows better applicability under the simulated marine atmosphere. Specifically, after 8+64CCTs, the corrosion rate of sample A1 decreased by 54%, while the proportion of α-FeOOH, the α/γ* value, and the self-corrosion potential (E_corr) increased by 15%, 0.55, and 0.29 V, respectively. The rust layer of Q420qNH WS primarily consists of γ-FeOOH, α-FeOOH, Fe₃O₄, and γ-Fe₂O₃. Surface stabilization treatment with sulfate-based stabilizers promoted the enrichment of Cu and Cr in the cracks, facilitating the filling of these defects and enhancing the stability and corrosion potential of the rust layer.