Selective nucleation and growth in 3% silicon steel

Due to the stronger bond strength of the Fe-S molecule than that of the Fe-Fe molecule, at the stage of nucleation the surface-segregated sulfur hinders the systematical movement of matrix atoms into the exact positions at the surface for the formation of the [110][001]. When the [110] grains form selectively at the strip surface, even a subdivision of a low concentration of surface-segregated sulfur determines, therefore, the degree of disturbance against movement of matrix atoms and, thus, the direction of the [110]: the [110][001] at a much lower concentration of surface-segregated sulfur and the [110][uvw]_≠[001] under a lower condition of segregated sulfur. Due to the relatively higher mobility of matrix atoms, the probability that, at a fixed final reduction, the [110] grains survive through the selective growth of [100] grains and have finally a chance for selective growth decreases with increasing heating rate.