Cyclic response-electrochemical interaction in mono- and polycrystalline AISI 316L stainless steel in H 2SO 4 solution—II. Potential dependence of the transient dissolution behavior during corrosion fatigue

Abstract

The transient current behaviors of an AISI 316L stainless steel, in both mono- and polycrystalline forms, have been studied in corrosion fatigue tests performed in a 1N H 2SO 4 solution, under different potentials. Extreme care in experimental technique and instrumentation have disclosed minute current variations which provide information about mechanisms. The effects of both the cyclic process and the applied potentials on the current behavior have been investigated, in following up a study of the influence of strain on the transient current behavior (Part I). Selective dissolution of iron from slip steps has been demonstrated to have a major influence on the transient current, during the early stage and the cracking stage of cycling, and does not depend on applied potentials. A significant potential dependence of the transient current was found, however, in the stage of stable current (saturation), which is correlated with different electrochemical reactions in the slip bands. Corrosion fatigue lives were measured and analyzed in relation to the current behavior.