Application of electrochemical methods to the investigation of corrosion fatigue of metals

Abstract

Using electrochemical methods, we investigate a process of corrosion fatigue fracture of stainless steels of various classes and LS59-1 brass in chloride-containing media. We establish the correlation between a change in electrochemical parameters in the process of corrosion fatigue and stages of fracture of specimens. We estimate the deformation activation of metals and its influence on the intensity of accumulation of corrosion fatigue damages, formation of pittings, and components of impedance. We show that cyclic stresses have different effects on dissolution of separate components of alloys, the intensity of which depends on the limiting stage of the electrode process (the diffusion stage or the electrochemical one). On the basis of the investigations performed, we conclude that the susceptibility of stainless steels to corrosion fatigue is determined by the efficiency of local activation and repassivation.