Crack Growth Rate and Fracture Toughness of CF3 Cast Stainless Steels at ~3 DPA

  • Y. ChenEmail author
  • W.-Y. Chen
  • B. Alexandreanu
  • K. Natesan
  • A. S. Rao
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)


Cast austenitic stainless steels (CASS) used in reactor core internals are subject to high-temperature coolant and energetic neutron irradiation during power operations. Due to both thermal aging and irradiation embrittlement, the long-term performance of CASS materials is of concern. To assess the cracking behavior of irradiated CASS alloys, crack growth rate (CGR) and fracture toughness J-R curve tests were performed on two CF3 alloys. Miniature compact tension specimens were irradiated to ~3 dpa, and were tested at ~315 °C in simulated LWR coolant environments with low corrosion potentials. No elevated cracking susceptibility was observed at this dose in the test environments. The power exponents of the 3 dpa J-R curves were much lower than that of unirradiated or irradiated specimens at lower doses, indicating a significant decline in fracture resistance. A preliminary microstructural study revealed irradiation-induced microstructural changes in both austenite and ferrite, suggesting an embrittlement mechanism involving both phases at this dose level.


Cast austenitic stainless steels Neutron irradiation Stress corrosion cracking Thermal aging Irradiation embrittlement Microstructural characterizations 



The authors would like to thank Ms. T. M. Karlsen, OECD Halden Reactor Project, Halden, for her help with the irradiation experiment and specimen transfer. Chi Xu and Loren Knoblich are acknowledged for their contributions to the experimental effort. The TEM work was performed at the IVEM-Tandem Facility funded by the US Department of Energy Office of Nuclear Energy. This work is sponsored by the U.S. Nuclear Regulatory Commission, under Project V6380, and by the U.S. Department of Energy, under contract # DE-AC02-06CH11357.


  1. 1.
    U.S. NRC, Expert panel report on proactive materials degradation assessment, NUREG/CR-6923, 2006Google Scholar
  2. 2.
    T. Meyer, C. Boggess, S. Byrne, R. Schwirian, F. Gift, R. Gold, Materials reliability program: screening, categorization, and ranking of reactor internals components for westinghouse and combustion engineering PWR design (MRP-191), EPRI Technical Report, Project Manager H. T. Tang, Nov 2006Google Scholar
  3. 3.
    F.H. Beck, J. Juppenlatz, P.F. Wieser, in Stress Corrosion—New Approaches, ed. by H.L. Craig, Jr. Effects of Ferrite and Sensitization on Intergranular and Stress Corrosion Behavior of Cast Stainless Steels (ASTM STP 610, 1976)Google Scholar
  4. 4.
    S. Floreen, H.W. Hayden, The influence of austenite and ferrite on the mechanical properties of two-phase stainless steels having microduplex structures. ASM Trans. Q. 61(3), 489–499 (1968)Google Scholar
  5. 5.
    W.J. Mills, Fracture toughness of type 304 and 316 stainless steels and their welds. Int. Mater. Rev. 4(2), 45 (1997)CrossRefGoogle Scholar
  6. 6.
    N.R. Hughes, W.L. Clarke, D.E. Delwiche, in Stainless Steel Castings, ed. by V.G. Behal, A.S. Melilli. Intergranular Stress-Corrosion Cracking Resistance of Austenitic Stainless Steel Castings (ASTM STP 756, 1982)Google Scholar
  7. 7.
    L.S. Aubry, P.F. Wieser, W.J. Pollard, E.A. Schoefer, in Stainless Steel Castings, ed. by V.G. Behal, A.S. Melilli Ferrite Measurement and Control in Cast Duplex Stainless Steels (ASTM STP 756, American Society for Testing and Materials, 1982), pp. 126–164Google Scholar
  8. 8.
    S.S. Brener, M.K. Miller, W.A. Soffa, Scr. Metall. 16, 831(1982)Google Scholar
  9. 9.
    P.J. Grobner, Metall. Trans. 4, 251 (1973)Google Scholar
  10. 10.
    O.K. Chopra, A. Sather, Initial assessment of the mechanisms and significance of low-temperature embrittlement of cast stainless steels in LWR systems (NUREG/CR-5385, ANL-89/17, 1990)Google Scholar
  11. 11.
    O.K. Chopra, W.J. Shack, Crack growth rates and fracture toughness of irradiated austenitic stainless steels in BWR environments (NUREG/CR-6960, ANL-06/58, 2008)Google Scholar
  12. 12.
    Y. Chen, B. Alexandreanu, W.-Y. Chen, K. Natesan, Z. Li, Y. Yang, A.S. Rao, J. Nucl. Mater. 466, 560–568 (2015)CrossRefGoogle Scholar
  13. 13.
    P.L. Andresen, F.P. Ford, S.M. Murphy, J.M. Perks, in State of Knowledge of Radiation Effects on Environmental Cracking in Light Water Reactor Core Materials. Proceedings of 4th International Symposium on Environmental Degradation of Materials in Nuclear Power Systems—Water Reactors (NACE, Houston, TX, 1990), pp. 1.83–1.121Google Scholar
  14. 14.
    J.W. Shack, T.F. Kassner, Review of environmental effects on fatigue crack growth of austenitic stainless steels (NUREG/CR-6176, 1994)Google Scholar
  15. 15.
    W.S. Hazelton, W.H. Koo, technical report on material selection and processing guidelines for BWR coolant pressure boundary piping (NUREG-0313, Rev. 2, 1988)Google Scholar
  16. 16.
    Y. Chen, B. Alexandreanu, W. Chen, Z. Li, Y. Yang, K. Natesan, and A.S. Rao, Crack Growth Rate and Fracture Toughness J-R Curve Tests on Irradiated Cast Austenitic Stainless Steels. 17th International Conference on Environmental Degradation of Materials in Nuclear Power Systems—Water Reactors, Ottawa, Ontario, Canada, 9–13 August 2015Google Scholar
  17. 17.
    Y. Chen, B. Alexandreanu, K. Natesan, Crack growth rate and fracture toughness tests on irradiated cast stainless steels (NUREG/CR-7184, ANL-12/56, 2015)Google Scholar
  18. 18.
    Z. Li, W.-Y. Lo, Y. Chen, J. Pakarinen, Y. Wu, T. Allen, Y. Yang, J. Nucl. Mater. 466, 201 (2015)CrossRefGoogle Scholar
  19. 19.
    Y. Chen, B. Alexandreanu, W.-Y. Chen, K. Natesan, Z. Li, Y. Yang, A.S. Rao, J. Nucl. Mater. 466, 560–568 (2015)CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society 2019

Authors and Affiliations

  • Y. Chen
    • 1
    Email author
  • W.-Y. Chen
    • 1
  • B. Alexandreanu
    • 1
  • K. Natesan
    • 1
  • A. S. Rao
    • 2
  1. 1.Argonne National LaboratoryDarienUSA
  2. 2.US Nuclear Regulatory CommissionRockvilleUSA

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