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Interaction and Multiscale Mechanics Volume 1, Number 4, December 2008 , pages 437-448 DOI: https://doi.org/10.12989/imm.2008.1.4.437 |
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Dislocation dynamics simulation on stability of high dense dislocation structure interacting with coarsening defects |
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M. Yamada, T. Hasebe, Y. Tomita and T. Onizawa
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| Abstract | ||
| This paper examined the stability of high-dense dislocation substructures (HDDSs) associated with martensite laths in High Cr steels supposed to be used for FBR, based on a series of dislocation dynamics (DD) simulations. The DD simulations considered interactions of dislocations with impurity atoms and precipitates which substantially stabilize the structure. For simulating the dissociation processes, a point defect model is developed and implemented into a discrete DD code. Wall structure composed of high dense dislocations with and without small precipitates were artificially constructed in a simulation cell, and the stability/instability conditions of the walls were systematically investigated in the light of experimentally observed coarsening behavior of the precipitates, i.e., stress dependency of the coarsening rate and the effect of external stress. The effect of stress-dependent coarsening of the precipitates together with application of external stress on the subsequent behavior of initially stabilized dislocation structures was examined. | ||
| Key Words | ||
| dislocation dynamics; dislocation substructure; creep strength; high Cr steel; multiscale modeling; field theory. | ||
| Address | ||
| M. Yamada, T. Hasebe and Y. Tomita; Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan T. Onizawa; Japan Atomic Energy Agency, Core and Structural Group, Advanced Nuclear System Research and Development Directorate, 4002 Narita, O-arai, Ibaraki 311-1393, Japan | ||
