Study the outdoor corrosion performance of Sn- and Mo-additional low alloy steel based on big data technology

In this study, the corrosion resistance of the novel designed Sn- and Mo-additional low alloy high strength steels was studied. The corrosion big data evaluation method was used to identify the small differences in corrosion resistance of trace alloying elements, and the chemical compositions of the unstable rust layer was characterized. Results suggest that the corrosion monitoring and evaluation methods based on corrosion big data technology can evaluate of the corrosion resistance and its evolution law of Sn- and Mo micro-alloyed low-alloy structural steel. The addition of 0.2% Sn can promote the corrosion resistance by increasing the uniform corrosion resistance. The addition of 0.1% Mo improves the pitting corrosion to a certain extent, while the addition of 0.1% Sn has no obvious improvement on uniform corrosion resistance. Corrosion mechanical depicts that Sn and Mo elements have two effects on the corrosion resistance of Cr-containing low-alloy structural steel. The effect of Mo is reflected in the inhibition of pitting corrosion behavior. In addition, its corrosion product MoO₃ is unstable, which is easy to hydrolyze in the rust layer and will accelerate the uniform corrosion process. The role of Sn is mainly manifested in the formation of stable SnO₂ oxide doped in the rust layer to increase the stability of the rust layer and thus slow down the uniform corrosion process of steel.