Tertiary recrystallization and magnetic induction under various annealing atmospheres in thin-gauged 3% Si-Fe strip

Surface-energy-induced secondary or tertiary recrystallization by grains with a specific surface plane can be freely governed in thin-gauged 3% Si-Fe strips by controlling the bulk content of sulfur and annealing atmosphere. During a vacuum or hydrogen annealing process, a convex profile in segregated-sulfur concentration is formed due to evaporation or desorption of segregated sulfur as a hydrogen sulfide, corresponding to a trough in magnetic induction. High magnetic induction is obtained after the annealing treatments. Final annealing under an argon atmosphere caused a saturation in segregated-sulfur concentration with annealing time. Under this extremely high segregated sulfur, grains of high index crystal plane including {111} continued to grow, resulting in low magnetic induction. (C) 2000 American Institute of Physics. [S0021-8979(00)27608-1].