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:
Jun. 06, 1995
Filed:
Nov. 22, 1993
Jerry W Schoen, Middletown, OH (US);
Armco Inc., Middleton, OH (US);
Abstract
The present invention provides a steel composition and method for producing a high quality regular grain oriented electrical steel having less than 0.005% aluminum using a single cold reduction step. A high austenite volume fraction, the use of an annealing separator coating with high sulfur or a sulfur bearing atmosphere to provide strong surface energy grain growth, a quench after initial annealing to provide the optimum microstructure having a small amount of martensite with a fine carbide dispersion and various chemistry changes are included in the method. Excess manganese in combination with tin, which has been found to act similarly to excess Mn, are maintained at a total level less than 0.03%. The use of chromium in an amount ranging from 0.11% to 1.2% provides outstanding control of stability for secondary grain growth. The finished regular grain oriented electrical steel has superior and more uniform magnetic quality than available from previous single stage processes and the magnetic quality is comparable to regular grain oriented electrical steels made using processes requiring two stages of cold reduction separated by an annealing step. The present invention also permits the production of thinner gauges while still using a single stage of cold reduction.