| 摘要 |
PURPOSE:To obtain the title annealing separating agent capable of uniformizing a glass coating film and improving the magnetic characteristic by regulating a Ca compd. a Ba compd., and a citric acid activity value in the process for producing MgO from Mg(OH)2, etc. CONSTITUTION:The magnesium oxide as the annealing separating agent for a grain-oriented magnetic steel sheet is produced from magnesium hydroxide, magnesium carbonate, basic magnesium carbonate, magnesium sulfate, magnesium chloride, and high-purity magnesium oxide. In the production process, the impurities and activity are regulated, the content of the Ca compd. is controlled to 0.04-0.2wt.% as CaO, the content of the B compd. is controlled to 0.04-0.2wt.% as B, [Ca% value] X [B% value] = 0.025-0.30 is satisfied, and the citric acid activity is controlled to 60-250sec. By this method, an annealing separating agent having a low hydrating property, an excellent adhesive property to a steel sheet, and excellent reactivity to a substrate coating film is obtained. |
