The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 06, 1976
Filed:
Oct. 11, 1974
James D Evans, Middletown, OH (US);
Armco Steel Corporation, Middletown, OH (US);
Abstract
Insulative coatings for electrical steels and methods of making them. The coatings are hard, glassy and smooth in nature, are easily cured and improve the magnetic characteristics of the electrical steels. The coatings are produced by applying to an electrical steel an aluminum-magnesium-phosphate solution containing Al.sup.+.sup.+.sup.+, Mg.sup.+.sup.+ and H.sub.2 PO.sub.4 .sup.- in a specified relative relationship and from 0 to 60% by weight colloidal silica on a water-free basis. The solutions contain at least 45% by weight water. Chromic anhydride (CrO.sub.3) may be added to the coating solutions to improve wettability of the solutions, moisture resistance of the resulting coatings and interlaminar resistivity after stress relief anneal. An electrical steel coated with a solution of the present invention is thereafter subjected to a heat treatment to cure the insulative coating thereon.