Multi-scale modelling of AISI H11 martensitic tool steel surface anisotropic mechanical behaviour

In this work, a numerical investigation is carried out on the anisotropic and heterogeneous behaviour of the AISI H11 martensitic tool steel surface using finite element method and a multi- scale approach. An elasto- viscoplastic model that considers nonlinear isotropic and kinematic hardenings is implemented in the finite elements code ABAQUS using small strain assumption. The parameters of the constitutive equations are identified using macroscopic quasi- static and cyclic material responses by the mean of a localization rule. Virtual realistic microstructures, consisting of laths and grains, are generated using particular Voronoi tessellations. These microstructures consider the specific crystallographic orientations alpha'/gamma Finite element investigation is then performed. The local heterogeneous and anisotropic behaviour of the surface as well as the subsurface is shown under quasi- static and cyclic mechanical loadings. The laths morphology and crystallographic orientation have an important impact on the local mechanical fields.