Influence of Ti Element on Corrosion Resistance of Cr Micro-Alloyed Steel in Harsh Marine Environment

The influence of Ti doping amount on the corrosion resistance of Cr microalloy steel was investigated by simulating a harsh marine atmospheric corrosion environment. The results indicate that Ti significantly enhances the thermodynamic stability of Cr microalloy steel and increases its corrosion potential. Additionally, as the Ti doping level increases from 0 to 0.087 wt %, the protective capability of the corrosion product layer is progressively improved. The corrosion rate of Ti-doped steel decreases from 2.24 to 1.75 mm/year, representing a 21.9% reduction compared to that of undoped steel. However, when the doping level exceeds 0.087 wt %, the enhancement in corrosion resistance becomes minimal, with little significant change in the corrosion rate. Furthermore, long-term corrosion studies of the product layers revealed a strong synergistic interaction between Ti and Cr, leading to greater enrichment of Cr in the product layers formed on Ti-doped steel. Moreover, Ti promotes the formation of γ-Fe2O3, which facilitates the development of a denser and more stable protective oxide layer.