Correlation between interfacial segregation and surface-energy-induced selective grain growth in 3% silicon-iron alloy

Effects of final reduction and interfacial segregation of sulfur on surface-energy-induced selective grain growth have been investigated in 3% silicon-iron alloy strips with various bulk content of sulfur. Interfacial segregation kinetics of sulfur varies with annealing atmosphere: a convex profile under vacuum or hydrogen and a gradual increase under argon. This is because the segregated sulfur evaporates or gasifies to hydrogen sulfide during final vacuum or hydrogen annealing, resulting in a sulfur-depleted zone just below the strip surface. The surface-energy-induced selective growth of a grain at time t is determined by the concentration of segregated sulfur. The selective growth rate depends on the combined effect of the segregated sulfur and the final reduction that determines the average grain size. For obtaining (110)[001] Goss texture, the final reduction should, therefore, be controlled, depending on the bulk content of sulfur which influences directly the segregation kinetics of sulfur and thus the texture development. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.