Effects of proton irradiation on nanocluster precipitation in ferritic steel containing fcc alloying additions

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Acta Materialia

DOI:https://doi.org/10.1016/j.actamat.2012.02.008· OSTI ID:1037657

Zhang, Zhongwu ^[1]; Liu, C T ^[2]; Wang, Xun-Li ^[1]; Miller, Michael K ^[1]; Ma, Dong ^[1]; Chen, Guang ^[3]; Williams, J R ^[2]; Chin, Bryan ^[2]

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1. ORNL
2. Auburn University, Auburn, Alabama
3. Nanjing University of Science and Technology

Newly-developed precipitate-strengthened ferritic steels with and without pre-existing nanoscale precipitates were irradiated with 4 MeV protons to a dose of ~5 mdpa at 50 C and subsequently examined by nanoindentation and atom probe tomography (APT). Irradiation-enhanced precipitation and coarsening of pre-existing nanoscale precipitates were observed. Copper partitions to the precipitate core along with a segregation of Ni, Al and Mn to the precipitate/matrix interface after both thermal aging and proton irradiation. Proton irradiation induces the precipitation reaction and coarsening of pre-existing nanoscale precipitates, and these results are similar to a thermal aging process. The precipitation and coarsening of nanoscale precipitates are responsible for the changes in hardness. The observation of the radiation-induced softening is essentially due to the coarsening of the pre-existing Cu-rich nanoscale precipitates. The implication of the precipitation on the embrittlement of reactor-pressure-vessel steels after irradiation is discussed.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Shared Research Equipment Collaborative Research Center
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1037657
• Journal Information: Acta Materialia, Vol. 60, Issue 6-7; ISSN 1359-6454
• Country of Publication: United States
• Language: English