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:
Dec. 30, 1997
Filed:
Feb. 28, 1997
Jerry W Schoen, Middletown, OH (US);
Norris A Dahlstrom, Hamilton, OH (US);
Christopher G Klapheke, Gibsonia, PA (US);
Armco Inc., Middletown, OH (US);
Abstract
The present invention provides a method of producing grain oriented electrical steel having excellent mechanical and magnetic properties. A hot processed strip having a thickness of 1.5-4.0 mm thickness a composition consisting essentially of 2.5-4.5% silicon, 0.1-1.2% chromium, less than 0.050% carbon, less than 0.005% aluminum, up to 0.1% sulfur, up to 0.14% selenium, 0.01-1% manganese and balance being essentially iron and residual elements, all percentages by weight. The strip has a volume resistivity of at least 45 .mu..OMEGA.-cm, at least 0.010% carbon so that an austenite volume fraction (.gamma..sub.1150.degree. C.) of at least 2.5% is present in the hot processed strip and each surface of the strip has an isomorphic layer having a thickness of at least 10% of the total thickness of the hot processed strip. The strip is cold reduced to an intermediate thickness, annealed, cold reduced to a final thickness and decarburized to less than 0.003% carbon. The decarburized strip then is coated on at least one surface with an annealing separator and final annealed to effect secondary grain growth. The electrical steel has a permeability measured at 796 A/m of at least 1780.