Method of providing an anti-stick coating on non-oriented, semi-processed electrical steels to be subjected to a quality anneal
US4367101A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1981 |
| Grant date | Jan 4, 1983 |
| Priority date | — |
| Expiry date | Apr 6, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C22/74
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A process of providing an inorganic anti-stick coating directly on non-oriented, semi-processed electrical steels by applying to such steels a coating solution containing Al.sup.+++, Mg.sup.++, and H.sub.2 PO.sub.4.sup.- in a specified relative relationship, the concentration of Al.sup.+++, Mg.sup.++, and H.sub.2 PO.sub.4.sup.- comprising 100 parts by weight calculated as Al.sub.2 O.sub.3, MgO and H.sub.3 PO.sub.4, respectively, on a water-free basis. The coating solution may additionally contain from 0 to 150 parts by weight of colloidal silica on a water-free basis. Chromic anhydride (C.sub.r O.sub.3) may be added to the coating solution to improve its wettability and improve the moisture resistance of the anti-stick coating. The coating solution is so diluted with water as to provide a uniform coating as thin as possible to prevent lamination sticking and having a coating weight of less than 2 grams per square meter on each side. The coated electrical steel is subjected to a heat treatment to cure the anti-stick coating thereon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.