| 摘要 |
PURPOSE:To manufacture a grain-oriented electrical steel sheet having very iron loss and high magnetic flux density and undergoing no deterioration in the magnetic characteristics by strain relief annealing by linearly forming specified recesses in the surface of a grain-oriented electrical steel sheet subjected to finish annealing and by heat treating the steel sheet at a proper temp. CONSTITUTION:Recesses are linearly formed in the surface of a grain-oriented electrical steel sheet subjected to finish annealing or having an insulating film formed after finish annealing. The recesses are formed to 30-1,000mum width and >5-30mum depth, exclusive of the insulating film, at 2-20mm intervals in the rolling direction within the range of 90-45 deg. to the rolling direction by projecting granules of a metal, plastics or the like or jetting water under high pressure. The steel sheet is then heat treated at >=750 deg.C. Thus, grain-oriented electrical steel sheets having small iron loss and maintaining the magnetic domain controlling effect even after strain relief annealing are manufactured in a noncontact means with high productivity. |
