1 PRODUCTION METHOD FOR GRAIN-ORIENTED ELECTRICAL STEEL SHEET AND PRIMARY RECRYSTALLIZED STEEL SHEET FOR PRODUCTION OF GRAIN-ORIENTED ELECTRICAL STEEL SHEET

摘要

C, S, and O in an amount of less than 50 ppm and less than 50 ppm, respectively, in terms of mass% or mass ppm, C: more than 0%, less than 0.08%, Si: 2.0 to 4.5% (ppm)-N (ppm) x (26.98 / 14.00) 30 ppm is controlled so that the sol.Al is controlled to be less than 100 ppm and the N is controlled to be more than 0 ppm and not more than 80 ppm (1), wherein the nitrogen content (N) of the steel slab before the primary recrystallization annealing, annealing or annealing is in the range of 1 to 10% by mass, and the balance is Fe and inevitable impurities, Or the nitriding treatment specified by the formula (2) is performed, and silicon nitride (Si₃N₄) Is precipitated on the grain boundary, and this silicon nitride functions as a restraining force of normal grain growth, whereby the deviation of the magnetic characteristics is greatly reduced, and the grain-oriented electrical steel sheet having good characteristics is industrially produced stably.If sol.Al-N x (26.98 / 14.00) 050 ppm N 1000 ppm ... (One)0 sol.Al-N x (26.98 / 14.00) 30(N-sol.Al x 14.00 / 26.98 + 100) /mo N / mo (2)