| 摘要 |
PURPOSE:To prevent furn on of steel plates, when annealing the coils of electrical sheets, by spreading the surface of steel plates with glass-like film forming agent mainly composed of MgO and annealing releasing agent such as Al2O3 and SiO2. CONSTITUTION:When annealing the coils of electrical sheets, a processing solution is spread in order to form a scale mainly composed of SiO2 of the steel plate surface and a glass-like film. This processing solution has MgO suspended in water, and is spread so that the MgO content may be 0.5 to 3 g/m<2> when dried. After drying this solution, a mixture of 1 or more oxides such as Al2O3,ZrO2, SiO2 and TiO2 is electrostatically spread, as annealing releasing agent, by 3 to 20 g/m<2> in less than 100- mesh size. This is immediately wound on the coil to be annealed in the hydrogen stream. A heat resistant film is formed on the steel plate at the time of high temperature annealing, so that the furn on of steel plate may be prevented. |
