Experimental Study On Effects Of Electromagnetic Annealing On Microstructures And Magnetic Properties Of Non-oriented Silicon Steel

Cold-rolled non-oriented silicon steel is used for rotor core material of the motor and generator in the rotating magnetic field with the good magnetic properties and process performance. It is a new generation of soft magnetic materials and the high-end products of iron and steel industry. The magnetic properties of cold-rolled non-oriented silicon steel is significantly affected by the microstructure,distribution of texture and the intensity of components.In this thesis, magnetic field was introduced into the annealing process of grain non-oriented silicon steel. The effects of magnetic field on microstructures and magnetic properties of non-oriented silicon steel were investigated by means of orthogonal experiment analysis.In order to investigate the effects of intensity of magnetic field, orientation of magnetic field, annealing temperature and holding time on magnetic property,microstructure and texture of low grade non-oriented silicon steel, based on the orthogonal experiment, low grade non-oriented silicon steel were annealed under different conditions and the magnetic properties were examined by orthogonal analysis so that the best processing parameters are picked. The results of experiment indicate that annealing temperature and intensity of magnetic field are the key factors of the specific saturation magnetization as well as intensity of magnetic field and holding time affects significantly on the specific remanent magnetization. The specific saturation magnetization and specific remanent magnetization of non-oriented silicon steel could reach 260.7emu/g and 18.265emu/g respectively when annealing temperature is 800℃with intensity of magnetic field being 3T by means of readjusting orientation of magnetic field and holding time. The results also showed that the magnetic annealing process affects the orientation obviously, Magnetic annealing tends to strengthen the favorableη(〈001〉∥RD) and {100} fibers and weaken the unfavorableγfiber, and the magnetic field at 3T or 5T is more effective to optimize texture. Recrystallization grain size becomes larger under magnetic annealing in comparison with convention annealing. . A magnetic annealing mechanism is therefore proposed in view of lowering the grain boundary mobility and providing an additional orientation-dependent driving force for grain boundary migration.