A Study of the Corrosion Behavior of Cold-Sprayed 304L Stainless Steel for Dry Storage Canisters

Dry storage canisters to store SNF are mainly fabricated from 304L SS. Under certain conditions of humidity, temperature and salt chemistry, their weldments are known to be susceptible to localized corrosion and SCC. Cold spray is emerging as a promising technique for repairing pits and cracks. In this investigation, the corrosion behavior of cold-sprayed 304L SS was compared to the baseline 304L SS substrate using DLEPR and EIS. Additionally, changes to the corrosion behavior after heat treatment (recrystallization and sensitization) and with the mechanical surface treatments of LSP and UNSM was also investigated. Characterization of the microstructure was conducted using SEM, EBSD, and EDS. The results indicate a notable difference between the cold-sprayed 304L SS and baseline material with significant impacts from the heat treatments on the corrosion behavior. The specific complexities as effected by the cold spray process, heat treatment and surface treatment will be presented and discussed.