Therefore, adding niobium could refine the primary recrystallized microstructure, which could provide proper microstructure for final annealing

Therefore, adding niobium could refine the primary recrystallized microstructure, which could provide proper microstructure for final annealing. dispersed. Considering that all specimens are treated in an identical way, it is reasonable to deduce that the pinning force of precipitates in cold-rolled sheet of S3 is the strongest. As a result, the grain growth is inhibited by precipitates during decarburization annealing process, and fine primary recrystallized microstructure is obtained in S3. Previous researches have proved that the Goss grains are easier to swallow fine and uniform primary grains surrounding them and become abnormal large size during final annealing process [24,25]. Therefore, adding niobium could refine the primary recrystallized microstructure, which could provide proper microstructure for final annealing. Meanwhile, it should be noticed that the difference between the primary recrystallized microstructure of Dihydrokaempferol S3 and S4 is really small, which indicates that adding 0.009 wt% Nb is enough for grain-oriented silicon steel. Open in a separate window Figure 4 Inverse pole figure (IPF) of primary recrystallized sheets with different Nb content (a) Nb-free, (b) Nb-0.005 wt%, (c) Nb-0.009 wt%, (d) Nb-0.025 wt%. Open in a separate window Figure 5 Grain diameter distribution after primary annealing. Open in a separate window Figure 6 Second phase particle exist around the grain boundary of primary recrystallized steel with 0.009 wt% Dihydrokaempferol Nb. 3.3. Effect of Nb on Texture of Primary Recrystallized Grain-Oriented Silicon Steel Figure 7 shows the 2 2 = 45 sections of orientation distribution functions (ODF) of four primary recrystallized sheets. It can be observed that all Dihydrokaempferol the specimens possess the same texture type, which are -fiber around 001 110 and -fiber around 111 112 . However, the intensity of texture is changed after adding niobium. The specimen without Nb shows strong -fiber with peaks at 001 110 , and the intensity of 001 110 is 5.54, as increasing Nb content, -fiber becomes weaker, and strong -fiber with peaks at 111 112 is obtained in S3, the intensity of 111 112 is 4.49. In this study, strong 001 110 and -fiber would form in cold rolled sheets with a heavy reduction rate of low carbon steel [26]. During the decarburization annealing, the recrystallization nucleation rate and grain growth rate are related to the stored energy of cold rolled deformed Dihydrokaempferol grains. The stored energy of deformed grains is higher, the grain of which prefers to nucleate during annealing process. It is known that the stored energy of deformed grains in oriented silicon steel depends on grain orientation, which decreases in following order: is a constant, is grain boundary mobility, is grain energy, is the critical size of matrix microstructure, is the size of secondary recrystallized grain, is shape factor, is pinning resistance. Assuming that the and are constant and ignoring the pinning effect, it can be concluded that the growth rate increases with the decreases of primary grain size. In addition, the precipitates prevent the normal growth of the primary recrystallized Dihydrokaempferol grains and promotes the abnormal growth of Goss grains during secondary recrystallization annealing. According to Section 3.1, the precipitates in nitrided sheet of S3 are the finest and the Rplp1 most dispersed, which would contribute to the complete abnormal grain growth during final annealing. Considering the precipitates microstructure and texture in primary recrystallized sheet, the S3 possesses the finest and the most dispersed precipitates, finest microstructure, and the largest volume fraction of favorable texture. For all these reasons, the grains.

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