PRIMARY RECRYSTALLIZATION ANNEALED SHEET FOR MANUFACTURING HIGH MAGNETIC FLUX DENSITY GRAIN-ORIENTED SILICON STEEL SHEET

摘要

PURPOSE: To manufacture a grain-oriented silicon steel sheet having high magnetic flux density by subjecting a high silicon steel slab to hot rolling and annealing, thereafter subjecting it to cold rolling into a thin sheet and thereafter executing decarburization annealing serving also as primary recrystallization annealing, secondary recrystallization annealing, purification annealing and stress relief annealing. ;CONSTITUTION: An Si steel stab contg. 3.0% Si is heated, is thereafter subjected to hot rolling, is successively annealed at 1150°C in a nitrogen atmosphere, is cooled and is thereafter worked into a thin sheet having a final sheet thickness by cold rolling. Next, this thin sheet is heated to 850°C in a mixed atmosphere of hydrogen and nitrogen, is subjected to decarburization annealing serving also as primary recrystallization annealing, is thereafter coated with a separation agent for annealing, is subjected to secondary recrystallization annealing at 1200°C in an Ar atmosphere and is subjected to stress relief annealing at 800°C in a nitrogen atmosphere. At this time, the extreme density N of the (110) plane to the random azimuth in the parallel face of the sheet face at 1/4 of the total sheet thickness from the surface to the central layer of the sheet thickness is regulated so as to satisfy the inequality after the primary recrystallization annealing, by that, the objective grain-oriented silicon steel sheet extremely high in magnetic flux density can stably be manufactured.;COPYRIGHT: (C)1993,JPO&Japio