| 摘要 |
PURPOSE:To form a superior forsterite film having uniform appearance and high adhesion by adding TiO2 before forming MgO when the titled coating material is manufactured by adding TiO2 to MgO as a principal component. CONSTITUTION:A grain-oriented silicon steel cold rolled to the final thickness is heated in an oxidizing atmosphere to form an oxide film contg. silica, and after applying a protective coating material for annealing, the steel sheet is subjected to finish annealing at a high temp. MgO powder contg. a Ti compound is used as the principal component of said coating material. The MgO powder is formed by adding TiO2 powder to Mg(OH)2 by 1-20wt% of the amount of Mg(OH)2 expressed in terms of MgO and by calcining the mixture. By this method a heat resistant insulating forsterite film having superior uniformity, adhesion and smoothness is easily obtd. The film does not deteriorate the magnetic characteristics and space factor. |
