Method of forming a forsterite insulating film on the surface of a grain-oriented silicon steel sheet
US4249966A · kind A · utility
10Cited by
3References
1Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1979 |
| Grant date | Feb 10, 1981 |
| Priority date | — |
| Expiry date | Oct 19, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/14783
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high adhesion uniform forsterite insulating film can be formed on the surface of a grain-oriented silicon steel sheet by the application of an annealing separator consisting mainly of magnesia having a narrow activity distribution defined by the citric acid activity of the magnesia which varies depending upon the variation of final reaction ratio of the magnesia as determined by the method for measuring the citric acid activity of magnesia, where the final reaction ratio of the magnesia is the ratio of that amount of the magnesia which finally reacts with citric acid to the total amount of magnesia mixed with the citric acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.