Finite element modelling of creep cavity filling by solute diffusion

Journal article (2018)

Authors

C.D. Versteylen RST/Fundamental Aspects of Materials and Energy - AS , (OLD) MSE-7
M.H.F. Sluiter (OLD) MSE-7
N.H. van Dijk RST/Fundamental Aspects of Materials and Energy - AS
Research Group
RST/Fundamental Aspects of Materials and Energy (AS) (TU Delft)
Copyright: © 2018 C.D. Versteylen, N. K. Szymański, M.H.F. Sluiter, N.H. van Dijk
DOI
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https://doi.org/10.1080/14786435.2017.1418097
Steel Precipitation Modelling FEM Self-healing Creep
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Published Date

2018

Language

English

Reuse Rights

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Faculty

Applied Sciences

Department

RST/Radiation, Science and Technology

Research Group

RST/Fundamental Aspects of Materials and Energy

Abstract

In recently discovered self healing creep steels, open-volume creep cavities are filled by the precipitation of supersaturated solute. These creep cavities form on the grain boundaries oriented perpendicular to the applied stress. The presence of a free surface triggers a flux of solute from the matrix, over the grain boundaries towards the creep cavities. We studied the creep cavity filling by finite element modelling and found that the filling time critically depends on (i) the ratio of diffusivities in the grain boundary and the bulk, and (ii) on the ratio of the intercavity distance and the cavity size. For a relatively large intercavity spacing 3D transport is observed when the grain boundary and volume diffusivities are of a similar order of magnitude, while a 2D behaviour is observed when the grain boundary diffusivity is dominant. Instead when the intercavity distance is small, the transport behaviour tends to a 1D behaviour in all cases, as the amount of solute available in the grain boundary is insufficient. A phase diagram with the transition lines is constructed.