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.