A growing interest of automotive industry in the use of high performance steels is observed. These materials are obtained thanks to complex manufacturing processes whose parameters fluctuations lead to strong variations of microstructure and mechanical properties. The on-line magnetic non-destructive monitoring is a relevant response to this problem but it requires fast models sensitive to different parameters of the forming process. The plastic deformation is one of these important parameters. Indeed, ferromagnetic materials are known to be sensitive to stress application and especially to plastic strains. In this paper, a macroscopic approach using the kinematic hardening is proposed to model this behavior, considering a plastic strained material as a two phase system. Relationship between kinematic hardening and residual stress is defined in this framework. Since stress fields are multiaxial, an uniaxial equivalent stress is calculated and introduced inside the so-called magneto-mechanical multidomain modeling to represent the effect of plastic strain. The modeling approach is complemented by many experiments involving magnetic and magnetostrictive measurements. They are carried out with or without applied stress, using a dual-phase steel deformed at different levels. The main interest of this material is that the mechanically hard phase, soft phase and the kinematic hardening can be clearly identified thanks to simple experiments. It is shown how this model can be extended to single phase materials.

Magnetic methods are widely used for the nondestructive evaluation of magnetic materials. Evaluation of the state of the material being measured requires accurate modeling of the behavior of the material associated to a low computation time. A two-scale reversible modeling for isotropic polycrystals is proposed. Magnetization and magnetostriction behaviors under uniaxial stress are simulated.

Magnetic non destructive methods are frequently used in the industries of steel since magnetic behavior demonstrates a good sensitivity to the microstructural and/or mechanical changes. Magnetic behavior is especially sensitive to plastic straining that occurs for example with the manufacturing of materials (cutting, punching). Evaluating the state of a material from a measurement requires a modeling of the behaviors of the material (local constitutive laws) involved that must on the other hand demonstrate low computation time. Such magneto-mechanical modeling is proposed, based on the so-called multidomain model.

Magnetic and magnetostrictive behaviors of magnetic materials are very sensitive to mechanical stress and especially to plastic deformation. A model based on the decomposition of a plastified material into mechanically hard and soft phases has been proposed. An appropriate experimental procedure is presented in order to validate the model. The magnetic and magnetostrictive behaviors of a dual-phase steel are carried out. Measurements are made at unloaded stress and under various applied stress to observe a recovery phenomenon predicted by the modeling. Experiments and modeling are compared.