| 摘要 |
PROBLEM TO BE SOLVED: To provide a high Mn grain oriented silicon steel sheet improved in magnetic properties, and a method for producing the same by forming uniform coating tight in adhesion and having electrical insulating properties on the surface. SOLUTION: This grain oriented silicon steel sheet is the one having a steel compsn. contg., by weight, 1.5 to 4.0% Si, 1.0 to 4.0% Mn and 0.003 to 0.030% sol.Al [also, Si(%)-0.5×Mn(%)<=2.0], in which the contents of C, N and S as impurities are respectively regulated to <=0.005%, and the balance Fe with inevitable impurities, and the surface is applied with coating by 0.5 to 15g/m<2> as Al2 O3 . As for the method for producing the grain oriented silicon steel sheet, the surface of the steel sheet is coated with a coating soln. in which the colloid of active alumina lines in the form of feathers having 0.5 to 5μm average dimension in the soln. as a separation agent for annealing in a finish annealing state for the purpose of secondary recrystallization and purification, and drying is executed. |
