|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Phase Transformations and Microstructural Evolution
||Microstructural Evolution and Embrittlement of Thermally Aged Cast Duplex Stainless Steels
||Sarah Mburu, R. Prakash Kolli, Samuel Schwarm, Daniel Perea, Jia Liu, Arielle Eaton, Sreeramamurthy Ankem
|On-Site Speaker (Planned)
Cast duplex stainless steel piping in light water reactors experience thermal aging embrittlement during service at elevated temperatures. Interest in extending the service life to 80 years requires an increased understanding of the microstructural evolution and corresponding changes in mechanical behavior. We characterized the statically cast CF–3 and CF–8 stainless steels employing state-of-the-art atom-probe tomography (APT). The microstructure and mechanical properties of the steels that are isothermally aged to 4300 h and 8600 h at temperatures between 280 °C and 400 °C are compared to the as-cast steels. The results illustrate that spinodal decomposition, G–phase precipitation, carbide formation, and interfacial segregation of elements between phases influence thermal aging embrittlement. The mechanical properties demonstrate a decrease in impact toughness and an increase in Vickers Micro-hardness during aging that is correlated to microstructural changes. This work is supported by the Nuclear Energy University Programs (NEUP), contract number DE-NE0000724.
||Planned: A print-only volume