Effect of heating rate of final annealing stage on secondary recrystallization in grain-oriented silicon steel

A grain-oriented silicon steel sheet was manufactured by slab reheated at "medium temperature" and two-stage cold rolling method. The function of heating rate on secondary recrystallization in grain-oriented silicon steel was investigated. The results show that: compared with 30 degrees C/h heating rate, the initial temperature of the secondary recrystallization can increase by 10 degrees C at the heating rate of 20 degrees C/h. Furthermore, the temperature region of secondary recrystallization also extended either with the increased heating rate. Even though the inhibitors maintain AlN, complex precipitation of AlN and sulphide in both heating rate, the average diameter and Zener factor of inhibitors are distinct. Inhibitors in the route of 20 degrees C/h heating rate express stronger inhibition than that of 30 degrees C/h, and the average diameter and Zener factor are 17.519nm and 3.925x10(-4)nm(-1), respectively. In addition, more Goss texture component and less gamma -fiber texture ({111}//ND) component form at the heating rate of 30 degrees C/h than 20 degrees C/h at 1000 degrees C, but the final Goss texture component of 20 degrees C/h is greater than 30 degrees C/h. The average grain size of the final annealing sheets increased with the heating rate decreasing from 30 degrees C/h to 20 degrees C/h, and iron loss reduced by 0.05W/Kg, the magnetic induction intensity increased by 0.025T.