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 wi th 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 segregat ed-sulfur concentration is formed due to evaporation or desorption of segre gated sulfur as a hydrogen sulfide, corresponding to a trough in magnetic i nduction. High magnetic induction is obtained after the annealing treatment s. Final annealing under an argon atmosphere caused a saturation in segrega ted-sulfur concentration with annealing time. Under this extremely high seg regated sulfur, grains of high index crystal plane including {111} continue d to grow, resulting in low magnetic induction. (C) 2000 American Institute of Physics. [S0021-8979(00)27608-1].