METHOD FOR MANUFACTURING GRAIN-ORIENTED ELECTRICAL STEEL SHEET HAVING HIGH MAGNETIC FLUX DENSITY AND EXCELLENT FILM CHARACTERISTIC

摘要

PROBLEM TO BE SOLVED: To obtain a grain-oriented electrical steel sheet which has a forsterite film having excellent film appearance and adhesion and also has excellent magnetic properties by effectively prevent the occurrence of film defects in a stock containing Bi. SOLUTION: In manufacturing the grain-oriented electrical steel sheet by using a stock containing Bi, TiO2 is added in an amount of >=3 pts.wt. per 100 pts.wt. of MgO into a separation agent for annealing composed essentially of MgO, water content in the separation agent for annealing after application and drying is regulated to <=0.5 g/m2 per side of the steel sheet, and further the length of residence time of a coil in the temperature region of 700 to 900 deg.C in the course of temperature raise at final finish annealing is regulated to <=60 h.