Effect of Mo, Cr on Corrosion Behavior of Low-carbon Weathering Steels

摘要

To investigate the effect of Mo, Cr on the atmospheric corrosion behavior of low-carbon weathering steel, experimental steel samples with different Mo, Cr contents were prepared by vacuum induction melting and rolling. Optical microscope, XRD, SEM and weight loss method were employed to study the weight loss and evolutions of rust phases at different stages of laboratory accelerated test involving cyclic wet/dry conditions in 0.1 mol/L NaCI environment. Results showed that, the corrosion resistance of experimental steels was improved with the addition of Mo and Cr. In the initial stage of corrosion, Mo and Cr accelerated the corrosion rate and denser rust layer formed quickly. Mo could refine grain in the rust as corrosion proceeded. Crystal phases were mainly composed of Fe_3O_4, γ-FeOOH and α-FeOOH in the rust. With the addition of Mo, the content of α-FeOOH increased, meanwhile, with the addition of Cr the content of γ-FeOOH decreased.