Stress Corrosion Cracking of Zircaloy-4 in Neutral Aqueous Chloride Solution

Abstract

The stress corrosion cracking resistance of Zircaloy-4 in neutral aqueous chloride solution at room temperature has been investigated using both the slow strain rate technique and static load tests. It is shown that see only appears for applied polarisation potentials close to or higher than the-pitting protection potential. When the strain rate is increased, an increase or a decrease of see susceptibility is observed according to the applied potential range. This results from competition between the anodic dissolution rate and the repassivation rate; the balance between these two processes is affected by the strain rate value. Specimens of longitudinal orientation appear to be more resistant than those of transverse orientation. Fractographic examination shows the presence of both cleavage and flutings only for the transversely oriented specimens. The differences between the two orientations are interpreted in terms of material texture.