Finite element modelling of creep cavity filling by solute diffusion

Finite element modelling of creep cavity filling by solute diffusion

Versteylen, C.D. (TU Delft RST/Fundamental Aspects of Materials and Energy; TU Delft (OLD) MSE-7)
Szymański, N. K. (Student TU Delft)
Sluiter, M.H.F. (TU Delft (OLD) MSE-7)
van Dijk, N.H. (TU Delft RST/Fundamental Aspects of Materials and Energy)

2018

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.

creep
FEM
modelling
precipitation
self-healing
steel

http://resolver.tudelft.nl/uuid:ff6b6732-8dfc-4700-ad9e-eb20e279c5f7

https://doi.org/10.1080/14786435.2017.1418097

1478-6435

Philosophical Magazine (London, 2003), 98 (10), 864-877

Institutional Repository

journal article

© 2018 C.D. Versteylen, N. K. Szymański, M.H.F. Sluiter, N.H. van Dijk