Jirou Harase

The Role of high Energy Boundaries and Coincidence Boundaries in the Secondary Recrystallization of Grain-oriented Silicon Steel

The probability of grains having misorientation angles at 20°–45° (IHE20–45) or a Σ9 orientation relationship (IcΣ9) was determined using the three dimensional orientation distribution obtained from the (100) pole figure. A primary recrystallized grain-oriented silicon steel specimen capable of evolving a sharp Goss texture was used. It was found that IHE20–45 was higher around the Goss orientation but not the highest in the primary texture. Goss orientation has the highest IcΣ9 in the primary matrix. The assumption that orientations with a higher IHE20–45 value can be nuclei for secondary recrystallization led to the prediction of secondary recrystallization not being present in the secondary recrystallization texture. However, no such contradictory prediction was made on the assumption that orientations with a higher IcΣ9 value can be nuclei for secondary recrystallization. It is concluded, therefore, that grains with misorientation angles from 20°–45°are not important in the selection mechanism of Goss secondary recrystallization.

INFLUENCE OF THE SECONDARY RECRYSTALLIZATION TEMPERATURE ON THE SHARPNESS OF GOSS SECONDARY RECRYSTALLIZATION TEXTURE

Primary recrystallized Fe–3%Si specimens containing AI and nitrided were annealed intermittently with the heating rate of 15℃/h in 100% N2 atmosphere. The magnetic induction B8 was measured after each annealing. The onset of secondary recrystallization was detected by the rapid rise of B8. The maximum B8 obtained was about 1.94 T when the onset temperature of the secondary recrystallization was around 1075℃ regardless of the initial grain size or nitrogen content.