Prevention Chemistry Control:

Plant chemistry is used to control corrosion. The category of corrosion determines the technique used for avoiding or minimizing the corrosion rate.

Passivators and Inhibitors

Passivation is the condition whereas a naturally active metal corrodes at an extremely low rate, possibly because of an oxide coating or an absorbed layer of oxygen.  A few chemical substances, known as passivators or inhibitors, if added to water, could give this category of passivation through undergoing reduction at the metal surface.  A general inhibitor is potassium chromate.