Paints for the Protection of Steel—a Review of Research into their Modes of Action

Research over a period of about 20 years into the mechanism of the protection of steel by paint films is reviewed. possibilities are: cathodic protection achieved with zinc-rich paints; anodic passivation, by degradation products of metal soaps, notably those of lead, formed by pigment/media interaction; and resistance inhibition which depends on the structure of the paint film. Further progress may come from metal pigments such as alummIUm or magnesium with the oxide cover of the particles made conducting by alloying or surface treatment, exploration of a larger range of metal soaps, and improvement of homogeneity in crosslinking in paint films to develop maximum resistance.