Role of low-level void swelling on plasticity and failure in a 33 dpa neutron-irradiated 304 stainless steel. (May 2023)

• Record Type: Journal Article
• Authors: Vo, H.T.; Frazer, D.; Kohnert, A.A.; Teysseyre, S.; Fensin, S.; Hosemann, P.
• Is Part Of: International journal of plasticity. Volume 164(2023)
• Publication Date: 2023-05
• Subjects: void swelling -- channel formation -- microscale bicrystal testing -- ductility -- intergranular cracking; Plasticity -- Periodicals; Plasticité -- Périodiques; Plasticity; Periodicals; 620.11233
• DOI: 10.1016/j.ijplas.2023.103577
• Languages: English
• ISSNs: 0749-6419

Abstract

Highlights: The neutron-irradiated materials with low void swelling show significant hardening, as measured from microtesile and nanoindentation tests, while maintaining good ductility (>60% strain). The void microstructure suppresses dislocation-channeling and leads to macroscopic-like necking in the microscale bicrystal specimens. Intergranular cracking is not observed in the un-notched and notched microscale bicrystal test specimens, which rationalizes previous macroscopic mechanical tests showing resistance to intergranular cracking. Abstract: Radiation damage introduces a wide range of defects in structural materials depending on the irradiation conditions. Irradiation-induced loops are known to lead to dislocation-channeling, which reduces the work hardenability and increases the susceptibility to intergranular stress corrosion cracking. In a higher temperature regime, void formation is an integral radiation-induced defect type in addition to radiation-induced loops. Previous bulk mechanical tests suggest that a high level of void swelling can lead to severe embrittlement while a low level of void swelling does not negatively affect intergranular cracking and ductility. This study utilized microscale bicrystal testing to evaluate the role of low-level void swelling on dislocation-channel suppression and intergranular cracking in a 33 dpa neutron-irradiated 304 stainless steels with 2% and 3.7% void swelling. The results provided direct observation on the suppression of dislocation-channel and intergranular cracking in the presence of low-level void swelling. Graphical Abstract: Image, graphical abstract