|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Environmentally Assisted Cracking: Theory and Practice
||Correlating Grain Boundary Microchemistry in Austenitic Stainless Steels with Their Susceptibility to Irradiation-assisted Stress Corrosion Cracking
||Mo-Rigen He, Drew Johnson, Bai Cui, Gary Was, Ian Robertson
|On-Site Speaker (Planned)
Irradiation-assisted stress corrosion cracking (IASCC) is a primary cause of failure for the austenitic stainless steels (SS) used in light-water nuclear reactors. However, it remains unclear why intergranular cracking is only initiated at a limited fraction of discontinuous intersections between dislocation channels (DCs) and grain boundaries (GBs). Here we present electron microscopy characterization of several sites of discontinuous DC-GB intersections in a 13Cr15Ni SS test bar after proton irradiation and straining in high-temperature water. A strong segregation of Ni and weak depletion of Cr are observed at random high-angle GBs, both enhanced in the vicinity of surface oxides or crack tip. Moreover, such radiation-induced segregation (RIS) can be spatially inhomogeneous, the cracked GB sites show significantly weaker RIS than un-cracked GBs. The critical role of GB microchemistry (specifically, Ni segregation) in the susceptibility to IASCC may be attributed to the modification of GB microstructure and the mechanisms of slip transfer.
||Planned: Supplemental Proceedings volume