The effect of phosphonates on the corrosion of carbon steel in heat-supply water

The effect of phosphonates used in Russian heat-power engineering on the corrosion of carbon steel in deaerated delivery water at 90 degrees C is studied. It is shown that introduction of phosphonates reduces the susceptibility of steel to local corrosion. A zinc complex of hydroxyethylidenediphosphonic acid (OEDP-zinc) is the most effective inhibitor of the anodic reaction.