Observation of Mn-Ni-Si-rich features in thermally-aged model reactor pressure vessel steels

Atom probe tomography was used to characterise two low-Cu (< 0.04 at. %) model steels after exposure to long-term thermal ageing. Mn-Ni-Si-rich features were observed to form after as little as 20,731 h (similar to 2.4 years) of ageing. The composition of these features were compared to those predicted by thermodynamic models and the similarities and differences are discussed. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

Atom probe tomography was used to characterize two low-Cu model steels after long-term thermal aging, revealing Mn-Ni-Si-rich features forming as early as 20,731 hours of aging (approximately 2.4 years). The composition of these features was compared to thermodynamic models, discussing both similarities and differences.