| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a grain oriented electromagnetic steel sheet having excellent magnetostrictive properties in which magnetostrictive vibration is suppressed, and noise reduction effect is brought. <P>SOLUTION: At first, the surface of a grain oriented electromagnetic steel sheet is provided with an inorganic mineral film essentially consisting of forsterite, and the upper layer thereof is provided with a film having an average density of ≥3.1 g/cm<SP>3</SP>and an average hardness of ≥15 GPa. For example, the upper layer film is formed by mixing colloidal silica and alumina sol in various ratios and baking the mixture to the steel sheet having the forsterite film in the temperature range of 900 to 1,050°C. <P>COPYRIGHT: (C)2007,JPO&INPIT |
