<p>Ferritic steels are important cladding and structural material for current and advanced reactors containing Fe as a primary compositional matrix element. Three models&nbsp;containing voids, inclusions such as P and nano oxides embedded in Fe were simulated using LAMMPS code.Interaction and unpinning&nbsp;mechanism of dislocation interations in models were observed and compared by analyzing its stregthening effect through stress stain curve&nbsp;.In&nbsp;considering the interaction of dislocation with voids, it was observed that for all void sizes, dislocation bypass void follow a similar to the orowan mechanism without any loop irrespective of any radii,&nbsp;while for P clusters,&nbsp;dislocation is&nbsp;trapped at the interface and leaves it after making a screw dipole shape and following orowan mechansim. Furthemore, the&nbsp;oxides'&nbsp;dislocation interaction in oxide dispersed in iron&nbsp;follow orowan unpinning&nbsp;mechanism along with loops around oxide. Atomic insights on interaction mechanism between P clusters with dislocation indicate that interaction mechanism is essentially the same for void and P cluster in Fe and their binary alloys i.e. Orowan mechanism whereas for oxide the orowan interaction mechanism along with dislocation around the oxide and it's &nbsp;direct&nbsp;dependence on the size of the oxide. This work will provide a unique and valuable insight into the strengthening mechanism due to dispersed oxides by providing new parameters for the multi-scale simulation. Our results demonstrate that oxide impedes dislocations and offers hindrance for edge dislocations to saturate further.The values of critical unpinning stress for all models was analyzed and compared.&nbsp;This study provides atomic insight into the onset of plasticity in iron alloys.</p>

Atomic Insights on Interaction Mechanism of Dislocation With Void/Impurity/Precipitates in BCC Iron

Paper Proceedings: https://asmedigitalcollection.asme.org/ICONE/ICONE28/volume/85246

2021 28th International Conference on Nuclear Engineering (ICONE28)

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