Grain oriented electrical steel sheet having specular surface
US5782998A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1994 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Jan 7, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/1294
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In order to provide a very low iron loss, it is necessary to render the surface of a steel sheet smooth (specular). In the present invention, this is effected in a finish annealing furnace to simultaneously attain a high magnetic flux density and a specular surface. Specifically, after the completion of decarburization annealing, a steel material is pickled to remove an oxide layer present on the surface of the steel sheet, coated with an annealing separator comprising a substance nonreactive or less reactive with SiO.sub.2 and then subjected to finish annealing to provide a grain oriented electrical steel sheet having a specular surface. Magnetic domain division and tension coating of the steel sheet can provide a low iron loss value. In the finish annealing, since no time is required for dehydration, the annealing time can be shortened.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.