Modeling of radiation-induced segregation in austenitic Fe-Cr-Ni alloys

Conference · Sat Nov 01 04:00:00 EST 1997

OSTI ID:541156

Allen, T R; Was, G S ^[1]

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1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences

To improve the ability to predict radiation-induced segregation (RIS) in austenitic Fe-Cr-Ni alloys, a model for predicting RIS is developed which calculates diffusion parameters based on local atomic configuration. Comparisons of RIS measurements in austenitic iron-base and nickel-base Fe-Cr-Ni alloys with calculations using the Perks vacancy-driven RIS model have shown that to accurately predict segregation trends, composition specific diffusion parameters must be used. This requirement limits the ability of the Perks model to predict segregation in Fe-Cr-Ni alloys for which no prior segregation measurements exist. To overcome this limitation, the improved model calculates migration energies using pair interaction energies to account for composition dependent diffusivities. The advantages of this approach are that a single set of input parameters can be used to describe a wide range of bulk alloy compositions, and the effects of local order can be easily incorporated into the calculations. A description of the model is presented, and model calculations are compared to segregation data to show that significant trends in the measured segregation data can be modeled using a single set of input parameters.

• DOE Contract Number: AC06-76RL01830
• OSTI ID: 541156
• Report Number(s): CONF-961202--; ISBN 1-55899-343-6
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHROMIUM ALLOYS
IRON ALLOYS
MATHEMATICAL MODELS
NICKEL ALLOYS
PHYSICAL RADIATION EFFECTS
SEGREGATION