What are the possible corrosive processes if a thin film of water is present on the surface of a carbon steel part?

When water gets on the steel part, the corrosion process begins. At the edges of the drop, where more oxygen is supplied, the cathodic process takes place, that is, O2 is reduced. In the center of the water droplet, the minimum air access takes place anode process The steel object contains Fe, which oxidizes. We make equations.
A / Fe – 2e = Fe 2+ / 2
K / О2 + 4Н + + 4е = 2Н2О / 1
Total Equation
2Fe + 2 + O2 + 2 H2O = 2Fe + 2 + 4 OH-
Molecular equation
2Fe + O2 + H2O = 2 Fe (OH) 2
This is how atmospheric corrosion of the steel part occurs.