Microstructural investigation of IASCC crack tips extracted from thimble tube O-ring specimens

Aäron Penders, Milan Konstantinovic, T. Yang, Rik-Wouter Bosch, Dominique Schryvers, Frédéric Somville

Research outputpeer-review


The microstructural features of intergranular irradiation-assisted stress corrosion crack tips from a redeemed neutron-irradiated flux thimble tube (60 dpa) have been investigated using focused-ion beam analysis and (scanning) transmission electron microscopy. The current work presents a close examination of the deformation field and oxide assembly associated with intergranular cracking, in addition to the analysis of radiation-induced segregation at leading grain boundaries. Evidence of stress induced martensitic transformation extending from the crack tips is presented. Intergranular crack arrest is demonstrated on the account of the external tensile stress orientation, and as a consequence of MnS inclusion particles segregating close to the fractured grain boundary. Exclusive observations of grain boundary oxidation prior to the cracking are presented, which is in full-agreement with the internal oxidation model.
Original languageEnglish
Article number153727
Pages (from-to)1-16
Number of pages16
JournalJournal of Nuclear Materials
StatePublished - Jul 2022

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