关键词: 铁, 磁场, 恒电位阳极极化, 不均匀溶解, 钝化

Abstract: The effects of magnetic field on anodic dissolution of iron in sulfuric acid were studied by potentiostatic polarization measurements and scanning electron microscopy observation. Magnetic field would reduce the surface film coverage fraction on electrode by enhancing the film dissolution process, thus made the electrode prone to active dissolution state. With increasing the applied potentials, magnetic field would accelerate the anodic dissolution, change the oscillation state or passive state to active dissolution state, or maintain the passive state, respectively. Potential for onset of passivation moved in the noble direction when magnetic field was imposed. At specific anodic potentials, denting occurred on two sides of the electrode paralleling to the gravitation direction due to localized accelerated dissolution induced by magnetic field. Uneven dissolution of iron in the presence of magnetic field was related to the relative configuration between magnetic field direction and the electrode surface , and the special concentration gradient at the electrode circumferential area.