Sodium nitrite as an inhibitor against the attack of sea water on steel. Part I. The influence of sodium nitrite on the area and intensity of attack

Abstract The prevention by sodium nitrite of the attack of sea water on steel has been studied in two ways. (a) Observation of the extent and nature of corrosion of mild steel specimens partially immersed in sea water containing nitrite. (b) Measurement of the corrosion currents using a divided cell. The appearance of a widespread brown discolouration on the steel at the higher nitrate concentrations is discussed and a catalytic mechanism is suggested for the inhibiting action of nitrite. The effect of mixing phosphates and nitrite is reported.