Visualizing and quantifying the influence of N-Mo synergy on corrosion resistance of stainless steel by dissolution-diffusion-deposition model

This work employed the “dissolution-diffusion-deposition” model to quantitatively describe the effect of N-Mo synergism on passivation process. The model was optimized by calibrating the ion concentration, calculating the equilibrium between H+ and OH−, as well as calculating the formation amount of passive film components. Through modelling studies, we visualized and quantified how N-Mo synergy promoted passivation process. Results demonstrate that N-Mo synergy enhanced corrosion resistance by suppressing acidification of solution, increasing Cr2O3 content and improving cation-selectivity of passive film. The mutual promotion between hydrolysis of NH3 and transpassive dissolution of Mo oxides played a critical role in improving corrosion resistance.