Special Rolling Path Process And The Effect On Microstructure And Properties Of Non-oriented Silicon Steel

Non oriented electrical steel is an important soft magnetic alloy material for the internal core of motor and generator.Its magnetic properties are mainly determined by grain size and recrystallization texture.At present,the research mainly focuses on the adjustment of rolling reduction and annealing process parameters for product optimization,while less research focus on optimizing texture by changing the rolling direction.In this paper,three new rolling schemes are proposed:skew rolling,cross rolling and cross rolling with intermediate annealing.Taking Fe-2.5%Si strip casting plate and Fe-3%Si conventional process normalized plate as the object,the evolution of microstructure and texture of non-oriented silicon steel by different cold rolling processes was studied.The results are as follows:(1)The evolution of microstructure and texture in the process of skew rolling were studied by using strip continuous casting and normalizing plate.The results showed that skew rolling can increase the number of shear bands in the cold rolling structure,the peak intensity of texture in conventional cold rolling was at {001}<110>orientation,while the peak intensity of texture by skew rolling rotated to the stable {223}<110>orientation and the y-fiber was enhanced.Among them,the {001}<100>orientation was reserved after skew rolling along 45°.After annealing,the sample of 45° skew rolling had strong Cube and Goss textures,leading to the maximum texture factor(V{001}+VGoss/V?111?).Thus,the magnetic induction of B50 was increased?0.03 T as compared to traditional rolling,and the iron loss of P1.5/50 was decreased?0.066 W/kg.(2)Cross rolling apparently changed the starting microstructure and texture of the second stage rolling due to the swap of rolling path.After the two-stage cold rolling,cross rolling resulted in very sharp {001?<110>orientation,and the typical ?-fiber texture was significantly weakended.After annealing,Goss texture appeared in each samples by different rolling paths.The cross rolling path HTD-HRD(transverse direction-rolling direction)led to the strongest Goss texture and the largest texture factor,showing the best magnetic properties.Compared to the conventional rolling path,the magnetic induction B50 was increased?0.03 T.(3)Cross rolling with the introduction of intermediate annealing led to inhomogeous microstructure.After intermediate annealing,the ?-fiber and y-fiber textures were weakened,and the ?-fiber texture was strengthened.Finally,the shear bands were distributed intensively in the cold rolled sheets,and there was strong ?-fiber in rolling texture.After annealing,the Cube texture in the cross rolling path HTD-HRD(transverse direction-rolling direction)was the strongest and the magnetic properties are the most superior.(4)Cross rolling experiments were conducted on industrial normalized plates.The results showed that the maximum intensity of the texture by conventional rolling was at {223}<110>,while that of two-stage cross rolling was {001}<110>orientation.After annealing,texture was apparently randomized.Cross rolling path HRD-HTD(transverse direction-rolling direction)led to strong ? texture and the highest texture factor(TF),resulting in an increase of?0.01 T of magnetic induction.