About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
|
Defects and Interfaces: Modeling and Experiments
|
Presentation Title |
The Effects of Nitrogen on Defect Evolution in Tempered Martensitic Steels |
Author(s) |
Stuart Andrew Maloy, Benjamin P. Eftink, Aaron Kohnert, H. Kim, C. Rietema, Eda Aydogan, Hi Vo |
On-Site Speaker (Planned) |
Stuart Andrew Maloy |
Abstract Scope |
The Advanced Fuels Campaign is developing and qualifying fuels for advanced reactors. To achieve this goal, new fuels and cladding materials are being tested to high burnup levels (e.g. >20%) which require cladding to withstand very high doses (greater than 200 dpa) while in contact with the coolant and the fuel. Tempered Martensitic Alloys are the leading candidates for these extreme service conditions. Irradiations performed on tempered martensitic alloys show that slight variations in the composition of one tempered martensitic alloy, HT9, can improve resistance to low temperature embrittlement. This material maintained 5% uniform elongation after irradiation to 6 dpa at 290C while all other alloys exhibited less than 2% uniform elongation. The reasons for these improvements in radiation tolerance are related to defect/interface interactions. To investigate the details behind these significant improvements, controlled alloys were produced while systematically varying the nitrogen concentration between 10 and 500 wppm nitrogen. Ion irradiations performed on these alloys showed that model alloys with higher nitrogen show a higher loop density while heats of HT9 with controlled nitrogen content show lower overall void swelling and a higher density of fine G-phase precipitates. These results will be summarized along with their correlations with radiation effects in tempered martensitic steels. |
Proceedings Inclusion? |
Planned: |