Production of grain-oriented silicon steel sheets having an insulating film formed thereon
US5174833A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1990 |
| Grant date | Dec 29, 1992 |
| Priority date | — |
| Expiry date | Jul 2, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C22/74
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for forming an insulating film on a grain-oriented silicon steel sheet by applying an insulating coating solution comprising 100 parts by weight (calculated as the solid component) of a mixture of colloidal substances, composed of 50 to 98 weight % (calculated as the solid component SiO.sub.2) of colloidal silica having a partical diameter not larger than 50 nano m, and 2 to 50 weight % (calculated as the solid component) of at least one colloidal substance having a particle diameter randing from 80 to 3000 nano m, selected from the group consisting of oxides, carbides, nitrides, sulfides, borides, hydroxides, silicates, carbonates, borates, sulfates, nitrates and chlorides of Fe, Ca, Ba, Zn, Al, Ni, Sn Cu, Cr, Cd, Nd, Mn, Mo, Si, Ti, W, Bi, Sr, and V, 130 to 250 parts by weight of at least one selected from the group consisting of phosphates of Al, Mg, Ca, and Zn, and 10 to 40 parts by weight of at least one selected from the group consisting of chromic anhydride, chromate, and dichromate. The insulating coating produces good surface film lubricity and good heat resistance and excellent workability when fabricating into a wound core as well as excellent iron loss properti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.