Study On Rolling And Annealing Process Of Non-Oriented Silicon Steel Produced By Strip Casting

Non-oriented silicon steel is an important soft magnetic material,widely used in the production of generators and motors.Low iron loss and high magnetic induction is the excellent magnetic performance indicators for the non-oriented silicon steel.The microstructure and texture of recrystallization is one of the key factors to determine the magnetic properties of non-oriented silicon steel,so it can provide some theoretical guidance for the improvement of magnetic properties of non-oriented silicon steel through the control of microstructure and texture.The effects of different cold rolling processes,intermediate annealing temperatures,different hot rolling processes and different annealing processes on the micro structures and texture of the high-grade non-oriented silicon steel produced by strip casting were investigated by X-ray diffraction and Electron backscattered diffraction(EBSD).The influence of different processes on the magnetic properties of the final finished plates was analyzed.The following research results are obtained:1.Grains of cast strip preferentially grow in the direction of {100}<0vw>under the action of the temperature gradient,and the adjacent columnar grains are also nearly {100}<0vw>oriented grains.The microstructure and texture of cast strip after normalizing rarely changes,which is due to small angle misorientation of two adjacent grain and low grain boundary migration rate.It is difficult for columnar grains to absorb the adj acent columnar grains with similar orientations by the mechanism of sub-grain merging and the decrease of grain boundary energy.2.The optimal magnetic properties of the final finished plates were obtained with high magnetic induction of 1.723T and low iron loss value of 3.10W/kg by the two-stage cold-rolling process.The highest magnetic induction intensity is obtained in the final finished plates due to strong Cube and Goss texture and weak y-fiber texture.The lowest iron loss is obtained in the final finished plates as a result of the appropriate and homogeneous grain size.3.The grain size of finished plates is relatively homogeneous by two-stage cold-rolling process,and the grain size is increased with the increase of intermediate annealing temperature.There are strong Goss and Cube texture and weak y-fiber texture in the finished plates with different intermediate annealing temperatures.Goss and Cube texture is enhanced and y-fiber texture is weakened with the increase of the intermediate annealing temperature.The optimal magnetic properties of the final finished plates were obtained with high magnetic induction of 1.750T and low iron loss value of 2.92W/kg by intermediate annealing at 1100?.4.The deformed {111}<112>,{111}<110>and {001}<100>grains in the partially recrystallized sample are mainly dominated by the two-stage cold-rolling process.The new Goss and Cube grains are mainly nucleated in the deformed {111?<112>and {111?<110>grains with 30 degree angle in the rolling direction.With the increase of the annealing temperature,the grain size of the intermediate annealed plates increases.When the plastic deformation occurs,the deformation band and shear band with coarse grains are more favorable for the nucleation of Goss and Cube grains,and Goss grains are more likely to nucleate in the deformed {111}<112>grains.5.The grain size of the annealed strips increases with the increase of the hot rolling reduction,and the intensity of the ?-fiber texture gradually increases,while the fraction of the y-fiber texture rarely changes with low intensity.The optimal magnetic properties of the final finished plates were obtained with cast strip hot rolled to 1.7 mm due to the high intensity of the ?-fiber texture.6.The effect of different annealing temperature on the microstructure,texture and magnetic properties of the finished plates is obviously stronger than that of the annealing time.With the increase of annealing temperature,the magnetic induction intensity of the finished plates increased gradually,while the iron loss value gradually decreased.However,with the increased of annealing time,the magnetic induction intensity firstly enhanced and then weakened,while the iron loss firstly decreased and then increased at the same annealing temperature.