Mechano-electrochemical study of Stress Corrosion Cracking at crack tip: case of Zircaloy-4 in halide solutions

摘要

The present study deals with the local quantification of mechano-electrochemical coupling at crack tip involved in SCC processes. A specific experimental procedure is developed and applied on Zircaloy-4 specimens in order to localize both electrochemical and mechanical damage using fatigue pre-crack and anodic polarization. Different experimental procedures of mechanical loading allow identifying several mechanical parameters influencing dissolution current measurements. Fracture surfaces observation reveals both intergranular and transgranular propagation modes of SCC for Zircaloy-4 tested in halide solutions. Transgranular propagation appears to be enhanced by large stress intensity induced by pre-cracking.