SURFACE TREATMENT OF ELECTRICAL STEEL SHEET

摘要

PURPOSE:To improve the suitability of an electrical steel sheet to blanking and welding by treating the steel sheet with a mixture of an emulsion contg. dispersed resin particles which is surface-treated with a dispersibility improver to improve the uniform dispersibility with an inorg. soln. CONSTITUTION:The surfaces of org. resin particles of 2-50mum particle size are treated with the dispersibility improver such as a nonionic or anionic surfactant. The treated org. resin particles are dispersed to prepare an emulsion. The mixture of the emulsion with an inorg. soln. contg. phosphoric acid and/or chromic acid is applied to the surface of an electrical steel sheet and baked to form an electrically insulating film having 0.5-1.5mum surface roughness Ra, the superior suitability to the blanking and the welding and superior insulation on the surface of the steel sheet.