Coincidence grain boundary and (100) [001] secondary recrystallization in Fe-3% Si

Abstract

The mechanism of the (100) [001] texture evolution by grain growth was investigated by X-ray diffraction and back-reflection Laue diffraction method. The main results obtained are as follows. (1) (100) [001] secondary recrystallization texture evolved from a primary texture having a major orientation of {236} 〈5 15 9⦔ and including precipitates of AIN and MnS. The deviation angle of secondary grains from an ideal (100) [001] orientation increased with elevating annealing temperature. The evolution of a small amount of secondary grains other than (100) [001] orientation are also observed. They are (100) [001] (at 1150°C) and (100) [001] (at 1100°C and 1200°C). (2) The mechanism of the evolution of the (100) [001] texture by secondary recrystallization was found to be due to the highest frequency of Σ7 coincidence boundaries in relation to (100) [001] orientation in the matrix texture before the onset of secondary recrystallization. The evolution of the (100) [001] oriented secondary grains at the latter stage of the secondary recrystallization annealing was considered to be due to the second highest frequency of Σ7 coincidence boundaries in relation to (100) [011] orientation. The increase in the scatter of the orientation of (100) [001] secondaries from an ideal (100)[001] orientation was considered to be due to the decrease in the frequency of Σ7 coincidence boundaries with increasing deviation angle from an ideal (100) [001] orientation. (3) Present results supports the hypothesis proposed by the present authors that grains having the highest frequency of coincidence boundaries in the matrix can grow largest in the grain growth process.