Study On Microstructure,Texture And Inhibitor Evolution Of Tin-oriented Silicon Steel During High Temperature Annealing

The only oriented silicon steel obtained through the secondary recrystallization process and mainly used to make the transformer core,like other metal materials,the internal metal structure also determines its magnetic properties.The most prominent feature of oriented silicon steel itself is its extremely strong Goss texture,that is,{110}<001>texture.The addition of Sn element in silicon steel can play an auxiliary inhibitory role in the initial recrystallization.Therefore,the addition of Sn element in silicon steel has become an important method for steel companies to develop and produce high-performance oriented silicon steel.At present,the primary recrystallization annealing and high temperature annealing can make the Gaussian grain orientation of oriented silicon steel form a single sharp Gaussian texture,thereby obtaining a high performance oriented silicon steel with excellent magnetic properties.Therefore,fully exploring the evolution of the organization,texture,and inhibitors of these two links in the production process has important scientific theory and technical practical significance for the design and production process of high-performance oriented silicon steel.In this paper,the tin-oriented silicon steel cold-rolled sheet produced by a large domestic steel mill,after the first recrystallization annealing and high temperature annealing,using advanced metallurgical microscope,scanning electron microscope,X-ray diffractometer and transmission electron microscope to study the production of steel mill The evolution law of microstructure,texture and precipitates of tin-oriented silicon steel during the first recrystallization annealing and high temperature annealing.By analyzing the experimental results,the first recrystallization has been completed when the annealing temperature is 830℃and the annealing time reaches 30s.As the annealing time is extended,the proportion ofΣ1 grain boundaries decreases,the proportion ofΣ3,Σ5,andΣ7 grain boundaries does not change much,and the proportion ofΣ9 grain boundaries increases to 1.126%;its recrystallization texture gradually replaces the traditional In cold-rolled texture,the orientation difference of the grains is mainly distributed between 20°-55°,and a peak appears at around 45°.At this time,the orientation difference of the grains has gradually been changed to the large angle grains.During the high-temperature annealing process of the sample,the sample began to recrystallize between 1000℃-1020℃.When the temperature reached 1020℃,the secondary recrystallization had been completed.The average grain size of Goss grains in the structure is smaller than the average grain size of the matrix at the corresponding annealing temperature,which does not occupy the size advantage.After the occurrence of secondary recrystallization,Goss texture gradually dominated,with an area fraction of 96.3%.With the increase of annealing temperature,the grain orientation of Goss gradually tends to the standard,which is conducive to the improvement of magnetic induction.The main precipitates during the high-temperature annealing process are AlN+MnS composites,and a small amount of precipitates Sn.The inhibitory power of precipitates during annealing decreases continuously as the volume fraction of precipitates gradually decreases.At900℃,the precipitates aggregate obviously.With the increase of annealing temperature,the Zener factor increases continuously at 900℃reached the maximum,and the distribution density of precipitates gradually reached the highest value of 8.9×10¹⁴/cm³.