NONORIENTED MAGNETIC STEEL SHEET HAVING EXCELLENT FILM PERFORMANCE, INSULATION FILM TREATMENT AGENT AND TREATMENT METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To produce a nonoriented magnetic steel sheet which has excellent appearance, corrosion resistance, weldability, blanking properties or the like even if an insulation film is thinly coated.;SOLUTION: The nonoriented magnetic steel sheet having excellent film performance is treated with an insulation film agent containing hyperfine particle resin with particle diameters of 0.04 to 0.19 μm and essentially consisting of chromic acid, and has an insulation film with a film thickness of 0.5 to 10.0 μm containing organic components by 2.5 to 25.0% as organic C. The insulation film agent for the nonoriented magnetic steel sheet is obtained by blending, to 100 pts.mass of chromic acid, one or more kinds selected from boric acid and borate by 10 to 45 pts.mass as boric acid, one or more kinds selected from MgO, CaO, ZnO and Al₂O₃ by 10 to 35 pts.mass, one or more kinds selected from glycerin, adipic acid and succinic acid by 10 to 30 pts.mass as a reducing agent, and resin emulsion containing hyperfine particle resin with particle diameters of 0.04 to 0.19 μm by 5 to 50 pts.mass as solid contents.;COPYRIGHT: (C)2003,JPO