|About this Abstract
||MS&T21: Materials Science & Technology
||Probing Defect Properties and Behavior under Mechanical Deformation and Extreme Conditions
||Elemental Partitioning Behavior among Precipitates in Alumina-forming-austenitic Stainless Steel
||Qing-Qiang Ren, David T. Hoelzer, Michael J. Lance, Yukinori Yamamoto, Michael P. Brady, Jonathan D. Poplawsky
|On-Site Speaker (Planned)
The microstructural stability of strengthening precipitates is critical for alumina-forming-austenitic (AFA) stainless steels for high temperature applications. The precipitates size kinetics subject to thermally aging and creep test at 750 oC was studied by SEM and (S)TEM, the results of which are related to the creep and mechanical properties. To better understand the precipitate stability, atom probe tomography (APT) was used to measure elemental partitioning among various precipitate interfaces in thermally aged and creep ruptured AFA samples. The corresponding energy reduction associated with the partitioning is calculated from the Gibbsian excess of alloying element additions. These results serve as a quantitative relation between alloying element additions and microstructural stability, which can guide future alloy design strategies. APT was performed at ORNL’s CNMS, which is a US DOE office of science user facility. The work is funded by U.S. DOE Office of Fossil Energy eXtremeMAT program.