Characterisation of dislocation behaviour in RPV steel

This deliverable reports DD simulation results on carbide strengthening in RPV steel at low temperature. We have shown that the interaction between dislocations and carbides depends on the local dislocation character. For screw dislocation, the strengthening is strongly dependent on the temperature, rate and carbide spacing. The strengthening is a complex function of these parameter but, in all cases, it increases with temperature. However, no significant temperature effect was observed in the case of non-screw dislocations. The behaviour of the dislocation microstructure in the presence of random distribution of carbides is rather complex. The strengthening depends on temperature strain rate. Whatever the simulation conditions, the strengthening increases with temperature and decreases with strain rate.