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

Figure 12

Depth profile by XPS on passive film of carbon steel passivated for 24 hours in simulated cooling water (1,000 ppm NaNO₂) at 25°C; (a) depth profile, (b) detail scan, (c) detail scan, and (d) detail scan.

(a)

(b)

(c)

(d)