An Overview on the Stress Corrosion Cracking Caused by Scratches on Steam Generator Tubes

This paper summarizes the theoretical model of scratches on the metal surface, the characteristics of the deformation zone caused by scratch and its impacts on stress corrosion cracking. The failure cases caused by scratches on steam generator tubes in pressurized water reactor nuclear power plants are introduced, and so are the sources of surface scratches and the corresponding repair methods or strategies. The effects of surface scratches on the stress corrosion failure of steam generator tubes and the research progress are discussed. The potential research topics and directions in the future are also proposed, such as further improving the theoretical model of surface scratches, deepening the understanding of the damage characteristics and stress corrosion mechanism in the affected area by scratches, the safety scratch threshold evaluation and surface repair methods.