The erosion of steel in moist air is the most prominent example of electrochemical erosion. In wet air, a thin film of water sticks to the surface of steel.

Hydrogen evolution erosion oxygen inhalation erosion

The water film is acidic and the water film is weakly acidic or neutral

Positive reaction 2H++ 2E -- =H2↑ O2+ 4E -- +2H2O=4OH --

Negative electrode reaction Fe -- 2E -- =Fe2+ 2Fe -- 4E -- =2Fe2+

Positive pole where the pH of the solution has increased

Other reactions Fe2+ +OH -- =Fe(OH)2↓ 4Fe(OH)2 +O2+2H2O= 4Fe(OH)3

I don't think there's such a thing as an anode process, a cathode process, a reaction

. If this layer of water film is strongly acidic, H+ electrons precipitate hydrogen, this electrochemical erosion is called hydrogen evolution erosion; If this layer of water film is weak acid or neutral, can dissolve more oxygen, at this time O2 gets electrons and precipitate OH -, this electrochemical erosion is called oxygen erosion, is the main cause of steel erosion.

The essence of metal atom is the process of loss of electrons by oxidation, can be generally divided into and.

It is the most common and important type of metal erosion.