| 摘要 |
PURPOSE:To form a glass film having fine appearance and high adhesion on a grain-oriented silicon steel sheet by coating the steel sheet with MgO suspended in water as a protective coating material for annealing, removing water of hydration from hydrated MgO by heating in a nonoxidizing atmosphere and carrying out finish annealing. CONSTITUTION:A grain-oriented silicon steel sheet having scale contg. SiO2 formed on the surface by decarburization annealing is coated with a protective coating material for annealing contg. MgO suspended in water as the principal component. The steel sheet is passed through a nonoxidizing atmosphere, where it is dried by heating to remove nearly completely water from the slurry on the steel sheet and water of hydration from Mg(OH)2 formed by the hydration of MgO. The steel sheet is then coiled at one and subjected to final finish annealing. By this method, a glass film having a uniform color tone, superior adhesion and superior magnetic characteristics can be formed. |
