Electrochemical prediction of corrosion behaviour of stainless steels in chloride-containing water

The pitting and crevice corrosion behaviour of stainless steels as a function of temperature and salinity (chlorides) of industrial waters has been considered in connection with environmental modification occurring because of the attack propagation. The actual meaning and the practical importance of the protection potential are examined and conclusions are drawn taking into account both the potential and non-potential dependent initiation and growth of corrosion phenomena. In this concern, the theoretical background and practical conditions for localized corrosion prevention by cathodic-anodic protection are discussed. Experimental stability diagrams of four stainless steel grades (AISI 304, 316, 430 and 410) at 22, 44 and 64°C are obtained and expressed in terms of electrode potential vs NaCl content in water.