Micromechanistic origin of irradiation-assisted stress corrosion cracking

Abstract

A multi-scale study of the micromechanics of dislocation–grain boundary interactions in proton and ion-irradiated stainless steels is presented. Interactions of dislocation channels with grain boundaries result in slip transfer, discontinuous slip without or with slip along the grain boundary. The presence of the irradiation damage enhances the importance of the magnitude of the resolved shear stress on the slip system activated by the grain boundary to transfer slip across it. However, the selected slip system is still determined by the minimization of the grain boundary strain energy density condition. These findings have implications for modelling the mechanical properties of irradiated metals as well as in establishing the mechanism for disrupting the grain boundary oxide, which is a necessary prerequisite for irradiation-assisted stress corrosion cracking.

Keywords:

• stress corrosion cracking
• IASCC
• irradiation
• dislocations
• in situ TEM

Acknowledgements

B. Cui would like to express his gratitude to Dr Mark Kirk (Argonne National Lab) and Dr Fuzeng Ren for their help with operation of the IVEM and EBSD, respectively. The electron microscopy was accomplished in the Frederick Seitz Materials Research Laboratory Central Facilities (University of Illinois) and the Electron Microscopy Center at Argonne National Laboratory, a US Department of Energy Office of Science Laboratory operated under Contract No. DE-AC02-06CH11357 by UChicago Argonne, LLC.

Additional information

Funding

Funding. This work was financially supported by the US Department of Energy [award number DE-FG02-08ER46525].