Secondary Recrystallization Texture in Fe-3%Si Cross-Rolled to 80% Reduction

Abstract

The Fe-3%Si steel containing inhibitors of AlN and MnS which was cross-rolled to 80% reduction evolved small numbers of (100) [011] secondarily recrystallized grains when annealed in 85%H₂-N₂ atmosphere and a secondary recrystallization texture having near (110) [001] when annealed in 100%N₂ atmosphere.
The difference of the secondary recrystallization behavior due to the annealing atmosphere was discussed as follows.
(1) The evolution of (100) [011] secondary recrystallized grains is considered to be due to the relatively higher intensities of (100) [011] and the matrix orientations having the Σ7 orientation relationship with the (100) [011] in the midplane of the thickness of the specimen before grain growth.
(2) The evolution of the secondary recrystallized grains near (110) [001] is considered to be due to the relatively higher intensities of (110) [001] and the intensity of the matrix orientations having the Σ9 orientation relationship with the (110) [001] near the surface of the specimen before grain growth.
(3) The occurrence of the (100) [011] secondary recrystallization when annealed in 85%H₂-N₂ is considered to be due to the shift of the nucleation site for the secondary recrystallization into the midplane where the inhibitor intensity is relatively higher, while the relative decrease in the inhibitor intensity near the surface layer results in the normal grain growth in the surface layer.
It is considered to be the reason for the occurrence of the (110) [001] secondary recrystallization in the surface layer when annealed in 100%N₂ atmosphere that the secondary recrystallization takes place at the temperatures lower than 1273 K in the very thin surface layer of the specimen where the intensity of the inhibitor, due to the lower amounts of MnS and AlN, is relatively lower, while the higher inhibitor intensity results in the prevention of the grain growth in the inner layer of the sheet.