PURPOSE: To provide the high-magnetic flux density electrical steel sheet which has no glass film and has an excellent iron loss characteristic by specifying the surface tension generated on the surface of the steel sheet by a film agent.
CONSTITUTION: Si is incorporated at 2.5 to 4.5% by weight into the electrical steel sheet. A primary film of ≤6.6g/m2 total of a forsterite material consisting of MgO, SiO2 and Al2O3 and a spinel material is formed as the oxide on the steel sheet surface, and further, the insulating film agent is formed at thickness of ≤6μm thereon. The surface tension generated on the steel sheet by this film material is 0.5 to 2.0kg/mm2. The high-magnetic flux density grain-oriented electrical steel sheet having the excellent iron loss characteristic of B8≥1.88 (Tesle) is formed. As a result, the grain-oriented electrical steel sheet of the ultra-low iron loss having the smooth surface is obtd.
MASUI HIROAKI
HONMA HODAKA
