Method for forming forsterite insulating film on an oriented silicon steel sheet
US4190469A · kind A · utility
3Cited by
4References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1978 |
| Grant date | Feb 26, 1980 |
| Priority date | — |
| Expiry date | Nov 2, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/14783
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Forsterite insulating films having a high adhesion on an oriented silicon steel sheet are formed by a method wherein an annealing separator consisting mainly of magnesia is applied on surfaces of the oriented silicon steel sheet and the steel sheet is wound up into a coil-form and then annealed at high temperatures to form forsterite insulating films, which is characterized by that the content of water carried into the coil together with the annealing separator is controlled depending upon the content of CaO component carried into the coil together with the annealing separator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.