About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Progressive Solutions to Improve the Corrosion Resistance of Nuclear Waste Storage Materials
|
| Presentation Title |
Mechanical perspectives on chloride-induced stress corrosion cracking of stainless steel |
| Author(s) |
Janelle P. Wharry, Lucille V Dentice, Ronit Roy, Nathan T Gehmlich, Thang Duc Nguyen, Maria A Okuniewski, Haozheng J Qu, Rebecca F Schaller, Mychailo Toloczko |
| On-Site Speaker (Planned) |
Janelle P. Wharry |
| Abstract Scope |
This talk presents mechanical mechanisms of chloride-induced stress corrosion cracking (CISCC) in 304L stainless steel. In the United States, more than 84,000 metric tons of nuclear waste are held in dry storage canisters made from 304L stainless steel within concrete overpacks. Chloride salt deliquescence onto canisters makes their vertical seam welds susceptible to CISCC. Historically, CISCC studies have emphasized electrochemical factors, with underlying mechanical drivers remaining poorly understood. Here, we review recent studies revealing the critical role of plasticity in CISCC propagation, and its interrelationship with electrochemical drivers. We present several key mechanisms: (i) the role of grain-to-grain Schmid and Taylor factor mismatch on CISCC propagation, (ii) crack-tip plasticity mechanisms observed through advanced electron microscopy methods, and (iii) internal pitting at phase and grain boundaries identified through correlative electron microscopy and x-ray tomography. Implications of these mechanisms on the lifetime of dry storage canisters will be discussed. |