Secondary Recrystallization of the Nitrided Fe-3%Si Alloy
Nitrided primary specimens containing 0.07% Bi were coated with MgO and annealed in 5%H<sub>2</sub>–N<sub>2</sub> (Box annealing). The magnetic induction (<I>B</I><sub>8</sub>) after Box annealing increased with increasing primary recrystallized grain size and decreased with increasing initial nitrogen content. The same primary recrystallized specimens were intermittently annealed in 100% N<sub>2</sub> without MgO coating (Model annealing). <I>B</I><sub>8</sub> was measured at each annealing. The onset temperature of the secondary recrystallization (<I>T</I><sub>cr</sub>) was detected by a steep raise of <I>B</I><sub>8</sub>. The maximum <I>B</I><sub>8</sub> decreased with increasing T<sub>cr</sub> from 1075 to 1100°C. The initial grain size and nitrogen content for the maximum <I>B</I><sub>8</sub> was different in both annealing methods. This difference was explained on the assumption that <I>T</I><sub>cr</sub> mainly determines <I>B</I><sub>8</sub> in both annealing methods. <br> The direct effect of Bi on the selective growth of sharp Goss orientation was small. Bi worked as an inhibitor for grain growth in the primary recrystallization annealing stage.
- ISIJ international
ISIJ international 38(10), 1114-1120, 1998-10-15
The Iron and Steel Institute of Japan