Localization and homogenization of the magnetomechanical fields in heterogeneous media are discussed. The magnetoelastic modeling for magnetic polycrystals is extended from the description of the singlecrystal modeling. This model is then applied to the prediction of the behavior of dual-phase steels. Each phase can be considered as a sphere embedded in a homogeneous equivalent medium. The magnetic model used for each phase is an explicit single-crystalline model representative of the behavior of the corresponding phase. Homogenization rules allow the simulation of the average medium. Experiments are carried out and compared to the numerical results.