Refining the identification methodology for describing heterogeneous Fe-Si materials using the viscoplastic self-consistent approach

Le résumé fourni par la source

Electrical steels stand as the predominant soft ferromagnetic materials in the power transmission industry. The magnetic properties of these steels are linked to a very specific crystallographic texture composed of centimeter-sized grains oriented along the Goss component. The formation of this texture is known to be directly linked with recrystallization mechanisms, abnormal grain growth during the high temperature annealing, as well as the texture evolution during cold rolling. Because of the complexity and heterogeneity of the deformed state, the key controlling parameters of the recrystallization mechanisms and then abnormal grain growth are not yet fully identified. In that context, to get a better understanding of the link between deformation and subsequent recrystallization mechanisms, the cold rolling stage is modelled in the present work as a first step. A viscoplastic self-consistent approach is used, to capture both texture and hardening evolution. The objective is to provide a qualitative and quantitative prediction of the microstructure and mechanical behavior resulting from the rolling process-induced cold deformation. It is thus necessary to establish a representative description of the heterogeneous Fe-Si material before this step: a novel identification methodology is introduced with that aim. Mechanical tests, consisting of tensile and simple shear at varying angles with respect to the rolling direction, were conducted for the sake of parameters identification and validation. Especially, a dislocation-based hardening model integrated in a viscoplastic self-consistent polycrystal framework is used. Required parameters, such as grain morphology, strain rate sensitivity, and microstructure heterogeneity, are discussed to enhance alignment with experimental data. • A new methodology is developed to characterize the heterogeneous Fe-Si steel. • We use a viscoplastic self-consistent model. • Parameters are identified by trial-and-error method on mechanical tests. • Validation is done on deformed texture.

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