Corrosion behavior of weathering steel in atmospheric environment containing fine particulate matter and the influence of stabilization treatment

Abstract

Abstract The corrosion behavior of weathering steel Q345qENH exposed to atmospheric environment in rich in fine particulate matter northwest China for 3 years was studied and the effects of stabilization treatment (Treatment method to accelerate the formation of stable rust layer on the surface) on the kinetic curves of the sample, the structure and physical phases, the electrochemical properties of the rust layer were analyzed. The long-term corrosion tendency of the two samples was predicted by kinetic model. The results shown that the corrosion rate of stabilized samples is greater than that of the untreated before 1 year , and the result is opposite after 1 year. In addition to α-FeOOH, γ-FeOOH, Fe2O3 and Fe3O4, the rust layer also contains a large amount of SiO2. The resistance of the rust layer of stabilized sample is 1.25 and 1.06 times higher than that of the untreated sample at 12 and 36 months of corrosion, respectively. In that environment, corrosion products nucleate with SiO2 as the base and encapsulate the soil dust to form particles of different sizes, which lead to poor bonding within the rust layer. The stabilization treatment improves the physical barrier effect of the rust layer, reduces the adhesion of SiO2 inside, and promotes the formation of dense rust layer.