Corrosion Inhibiting Mechanism of Nitrite Ion on the Passivation of Carbon Steel and Ductile Cast Iron for Nuclear Power Plants

Figure 9

Surface electrolyte potential (V(SCE), the right vertical color bar) obtained by computer 3D simulation (the unit of -, -, and -axes; μm) using COSOL Multiphysics on corrosion propagation with immersion time of ductile cast iron occurred in stagnant simulated cooling water (10,000 ppm NaNO₂) at 25°C; (a) 0 hour, (b) 24 hours, (c) 48 hours, (d) 72 hours, and (e) 144 hours.

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