Secondary Recrystallization in Fe-3%Si Containing AlN as Inhibitor

Fe-3%Si containing AlN, which was cold-rolled with 84.7% reduction and primarily recrystallized, was heated with the heating rate of 15°C/h in the 85%H2-N2 (condition A) or in the 5%H2-N2 atmosphere (condition B) up to a temperature of 1200°C and extracted from 925°C at intervals of 50°C. The secondarily recrystallized grains were observed at 975°C in condition A, while no secondarily recrystallized grains were found in condition B at this temperature. The secondary recrystallization was completed at 1025°C in both conditions. No (101)[010] oriented secondary grains were observed in specimen A extracted at 975°C. However, the main secondarily recrystallized texture at 1025°C was (101)[010] in both conditions. The scatter from the ideal (101)[010] orientation was smaller and the grain size was larger in B condition compared with condition A at this stage. However, the scatter in condition B was larger compared with the one processed from the primarily recrystallized specimen containing both AlN and MnS as inhibitors.These results are discussed from the viewpoint of grain boundary migration characteristics of coincidence boundaries and the following conclusion were derived.(1) In the weaker inhibitor condition, selective migration of other than Σ9 type boundaries occurs in the lower temperature range and selective migration of Σ9 type boundaries mainly occurs over a higher temperature range.(2) In the stronger inhibitor condition, selective migration of grain boundaries initiates over the higher temperature range and they are mainly Σ9 type boundaries.