Effect of AIN on the secondary recrystallization of 3%Si-Fe alloy.

Abstract

The relationship between the sharpness of secondary recrystallization texture and the morphology of AlN during secondary recrystallization was investigated through changing the dew point of primary annealing and the dew point and the N2 partial pressure of secondary annealing atmosphere. The main conclusion is summarized in the following.(1) The secondary recrystallization initiates near the surface layer of primary matrix when a gradient of the intensity of the inhibitor along the thickness direction is formed and reaches to a certain level at the specific temperature while the matrix grains are inhibited to grow because of the higher intensity of inhibitor. Here the intensity of inhibitor is defined as f/r (f: volume fraction of AlN or MnS, r: mean radius of AlN or MnS). The intensity gradient of AlN along the thickness direction is formed by the selective oxidation of Al during secondary recrystallization annealing.(2) A critical temperature (Tcr) is required for the initiation of secondary recrystallization. The annealing temperature above Tcr weakens the sharpness of Goss oriented secondary. The results of secondary recrystallization behavior are explained in terms of the distribution of coincidence boundaries and their migration characteristics controlled by the intensity of the inhibitor.