Ultra-high magnetic flux density grain-oriented electrical steel sheet excellent in iron loss at a high magnetic flux density and film properties and method for producing the same
US7399369B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 2002 |
| Grant date | Jul 15, 2008 |
| Priority date | — |
| Expiry date | May 9, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/1272
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention is a grain-oriented electrical steel sheet characterized in that Bi is present at 0.01 to less than 1,000 ppm in terms of mass at the interface of the substrate steel and the primary film of the grain-oriented electrical steel sheet. The grain-oriented electrical steel sheet is produced by any of the processes of: before decarburization annealing, applying preliminary annealing for 1 to 20 sec. at 700° C. or higher and controlling an atmosphere in the temperature range; controlling the maximum attaining temperature B (° C.) before final cold rolling so that the maximum attaining temperature B may satisfy the expression, −10×ln(A)+1,100≦B≦10×ln(A)+1,220, in accordance with a Bi content A (ppm) and at the same time heating the steel sheet cold rolled to the final thickness to 700° C. or higher within 10 sec. or at a heating rate of 100° C./sec. or more before decarburization annealing, or immediately thereafter applying preliminary annealing for 1 to 20 sec. at 700° C. or higher; or controlling a TiO2 amount B added in relation to MgO of 100 as parts by weight and an MgO coating amount C (g/m2) so that the expression, A0.8≦B×C≦400, may be satisfied in accordance…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.