Yellow metal deactivators as protection
Corrosion of non-ferrous metals is mainly understood to include the action of acid on bronze, nonferrous metals and white metals. The action of nonferrous metal deactivators is largely based on the formation of a passivating film on the surface of the metal.
Metal surfaces or (salts of) metals dissolved in oil catalytically promote aging of the oil. Metal deactivators are employed as a means of preventing this. The process involves “encapsulating” the metals or metal ions. This stops the unwanted catalytic action. Complex organic sulphur and nitrogen compounds prove to be especially suitable for this purpose.