Multi-scale characterization of stress corrosion cracking of cold-worked stainless steels and the influence of Cr content

This paper describes a novel multi-scale study of stress corrosion cracking in cold-worked 304 type stainless steels, which are widely used in pressurized water reactors and boiling water reactors. The influence of cold work and Cr concentration on the stress corrosion cracking behaviour of the steel has been examined. A methodology has been developed in order to characterize the same crack tip region with nanoscale secondary ion mass spectroscopy, electron back-scattering diffraction and transmission electron microscopy. This has offered a unique insight into the chemistry and microstructure, showing that the right combination of techniques can provide much of the information needed to understand the processes involved in crack propagation. A model for crack propagation based on brittle fracture and localized oxidation and shearing near the crack tip has been proposed.