Influence of temperature on the localized corrosion of stainless steels

Localized corrosion processes of passive metals are almost always initiated at local heterogeneities of the substrate material. In the case of stainle ss steels MnS inclusions are of primary importance. Increasing the temperat ure strongly accelerates the pitting. Detailed large-scale and microelectro chemical investigations show that this is mainly caused by an enhanced anod ic dissolution facilitating stable pit growth and retarding repassivation. Activation of new inclusions, remaining inactive at lower temperature, may also occur but are of minor importance.