Dislocation density evolution in Eurofer97: Nanoindentation study supported by FEM and STEM

A computational approach based on crystal plasticity finite element method is developed to simulate the nanoindentation process in reduced activation ferritic/martensitic steel Eurofer97. The method captures the evolution of dislocation density due to the deformation induced by the indenter tip. This evolution is validated in accordance with scanning transmission electron microscope observations of the indented subsurface area extracted using a focused ion beam. Measured dislocation densities at selected depths are compared with the corresponding computational predictions to assess the accuracy. The present work aims to validate and extend previous developments on combining experiments and simulations, with the long-term goal of predicting neutron-induced hardening using ion-irradiated material as a proxy. • Material response to plastic deformation is well reproduced computationally. • Indented sub-surface areas of Eurofer97 are examined with STEM. • Deformation-driven evolution of dislocation density is studied and simulated.