Is a more negative corrosion potential more susceptible to corrosion or a less negative corrosion potential?

A more negative corrosion potential signifies a higher susceptibility to corrosion. The corrosion potential, also known as the electrode potential or half-cell potential, is a measure of the tendency of a metal to corrode. It represents the voltage difference between the metal and a reference electrode (such as a standard hydrogen electrode) in an electrochemical cell.

The corrosion potential is measured in volts (V) and can be positive or negative. A more negative corrosion potential indicates a greater tendency for the metal to corrode, meaning it is more susceptible to corrosion. In this case, the metal is likely to undergo oxidation and form corrosion products on its surface more readily.

On the other hand, a less negative, or positive corrosion potential, suggests a reduced vulnerability to corrosion. A metal with a positive corrosion potential tends to be more corrosion-resistant. It indicates that the metal is less likely to undergo oxidation and form corrosion products, making it less susceptible to corrosion.

To determine the corrosion potential for a specific metal in a given environment, electrochemical techniques, such as potentiodynamic polarization or electrochemical impedance spectroscopy, are commonly employed. These techniques involve measuring the current produced by the metal at different potentials and analyzing the resultant polarization curves to determine the corrosion potential.

In summary, a more negative corrosion potential indicates a higher susceptibility to corrosion, while a less negative or positive corrosion potential suggests a reduced vulnerability to corrosion.