Corrosion Resistance of Weathering Steel Containing Niobium in Marine Atmospheric Conditions

Weathering steels (low Nb weathering steel and high Nb weathering steel) with different amounts of niobium were developed. Corrosion behaviors of the two kinds of niobium-containing weathering steels under marine atmospheric conditions were studied by means of accelerated corrosion test, electrochemical test and corrosion morphology characterization. The results show that the corrosion rate of high Nb weathering steel was lower than that of low Nb weathering steel in the initial stage of corrosion. Increasing the content of Nb in the alloy could improve the composition of rust layer, increase the self-corrosion potential and reduce the corrosion current density. As the corrosion time increased, the corrosion effect of Nb on weathering steel was reduced to negligible.