The Evolution Of Microstructure And Texture Of High Silicon Steel Thin Strip On Deformation And Recrystallization

The high silicon steel with silicon content of 6.5%has an excellent soft magnetic property,such as high magnetic permeability,approximate zero magnetostrictive coefficient,etc.The advantages in the case of high frequency are so obvious,because core loss and noise pollution are significantly reduced.So high silicon steel with silicon content of 6.5%is a suitable material to manufacture high speed and high frequency motor,high frequency transformer core,choke coil,audio and high frequency magnetic shielding device.The magnetic performance of high silicon steel is sensitive to its texture,? texture is the best component of high silicon steel,however,high silicon steel is easily formed harmful y texture after cold rolling and annealing,so the texture is difficult to optimize.Adding inhibitors to promote secondary recrystallization of high silicon steel is an ordinary method to gain ?texture,but if using this method to manufacture device,the device have to remove inhibitor by high temperature annealing in the atmosphere of hydrogen,so the cost of manufacturing is high.This experiments by adding some element of alloy and using secondary cold rolling method successfully manufactured 0.3mm oriented silicon steel thin strip without adding inhibitors.And using XRD and EBSD technology to research formation mechanism and transform rule of deformation and recrystallization structure,the main conclusions are the following ones:(1)The structure of normalizing,the first cold rolling and the secondary cold rolling with high silicon steel is significantly influenced by carbon content:with the carbon content rising,the grain of normalizing bands is obviously refined,the density of shear band rise the first cold rolling and the secondary cold rolling sheets.Due to decarburization phenomenon in the hot rolling process in the near surface layer,the center of higher carbon content will promote the carbide precipitation,resulting in the normalizing in grain refinement,which led to the density of shear band in the cold rolled increasing.(2)The carbon content obviously affects secondary cold rolled texture of high silicon steel,the stronger ? deformation texture can be formed at the appropriate carbon content(0.055%),which is conducive to form cube and other favorable texture during the annealing process.(3)Initial and secondary recrystallization microstructure and texture were significantly affected by carbon content:when carbon content is 0.055%,? grain occurred obvious secondary recrystallization,the orientation of the grain of secondary recrystallization is near to the cube orientation.The reasons of ? grain occurred secondary recrystallization may be related to the smaller initial recrystallization grain,strong cube texture and weak ? initial recrystallization texture,and ? grain with character of high mobility of the grain boundary.