GRAIN ORIENTED SILICON-IRON WITH A UNIQUE INHIBITION SYSTEM FOR TEXTURE DEVELOPMENT

The new high induction grain oriented silicon iron alloys (Fe-3Si) are characterized, compared with the conventional alloy, by a heavier final cold reducton and increased restraint to normal grain growth. It is shown that the conventional alloy possesses sufficient restraint to normal grain growth to undergo secondary recrystallization when it contains manganese sulfide but not when it contains sulfur only as solute. However, the presence of boron, nitrogen, and unncombined sulfur leads to strong grain growth inhibition and, when the strip is heavily cold rolled, to a high induction. A deficiency in any one of the three elements results in grain coarsening rather than a nearly constant grain size over a broad temperature range prior to secondary recrystallization.