If dissolved oxygen increases and the pH and alkalinity do not increase, the corrosion rate will generally:

If dissolved oxygen increases and the pH and alkalinity do not increase, the corrosion rate will generally:

• A. Increase
• B. Decrease
• C. Remain the same
• D. Fluctuate

Answer: (A)

Raising dissolved oxygen increases the amount of oxidant available to attack metal surfaces. In electrochemical corrosion, the metal dissolves as electrons are released while oxygen is reduced at the cathodic sites. More oxygen speeds up this cathodic reaction, pulling the overall corrosion process faster. If pH and alkalinity stay the same, there isn’t additional buffering or protective film formation to offset this, so the net effect is a higher corrosion rate.

Raising dissolved oxygen increases the amount of oxidant available to attack metal surfaces. In electrochemical corrosion, the metal dissolves as electrons are released while oxygen is reduced at the cathodic sites. More oxygen speeds up this cathodic reaction, pulling the overall corrosion process faster. If pH and alkalinity stay the same, there isn’t additional buffering or protective film formation to offset this, so the net effect is a higher corrosion rate.