Published November 2020 | Version v1
Journal article

Role of residual ferrites on crevice SCC of austenitic stainless steels in PWR water with high-dissolved oxygen

  • 1. Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)
  • 2. Korea Institute of Materials Science, Changwon (Korea, Republic of)

Description

The crevice stress corrosion cracking (SCC) susceptibility of austenitic stainless steels was evaluated in simulated pressurized water reactor (PWR) environments. To simulate the abnormal condition in temporary clamping devices on leaking small bore pipes, crevice bent beam (CBB) tests were performed in the oxygenated as well as hydrogenated conditions. No SCC cracks were found for SS316 in both conditions. SS304 also showed good resistance in the hydrogenated condition. However, all SS304 specimens showed SCC cracks in the oxygenated condition, indicating poor crevice SCC resistance. It was found that residual ferrites were selectively dissolved because of the galvanic corrosion coupled with the neighbouring austenite phase, resulting in SCC initiation in SS304. Crack morphologies were mostly transgranular assisted by the damaged δ-ferrite and deformation-induced slip bands

Additional details

Publishing Information

Journal Title
Nuclear Engineering and Technology
Journal Volume
52
Journal Issue
11
Series
31 refs, 12 figs, 4 tabs
Journal Page Range
p. 2552-2564
ISSN
1738-5733