Method of producing grain oriented silicon steel sheets each having a low watt loss and a mirror surface
US5129965A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1991 |
| Grant date | Jul 14, 1992 |
| Priority date | — |
| Expiry date | Jul 18, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/1288
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of producing grain oriented silicon steel sheets each having a low watt loss, at an inexpensive cost and a high operational efficiency, wherein surfaces of each silicon steel sheet are given a mirror surface is disclosed. After completion of a finish annealing, forsterite films on the surface of each grain oriented silicon steel sheet are removed therefrom, and thereafter, the silicon steel sheet is annealed within the temperature range of 1000.degree. C. or higher in an atmosphere composed of a mixture gas comprising 20 to 80% by volume of hydrogen gas and 0 to 80% by volume of an inert gas, whereby surfaces of the silicon steel sheet are given a mirror surface. Subsequently, tensile stress additive films are formed on the surfaces of the silicon steel sheet, and consequently, the resultant silicon steel sheet exhibits a remarkably reduced watt loss.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.