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. 29, 1992
Filed:
Jul. 16, 1991
William A Bertol, Wheeling, WV (US);
Yoshio Hayashi, Wheeling, WV (US);
James B Hill, Natrona Heights, PA (US);
Eisuke Otani, Wheeling, WV (US);
Donald R Zaremski, Cheswick, PA (US);
John P Ziemianski, Avonmore, PA (US);
Wheeling-Nisshin, Inc., Follansbee, WV (US);
Allegheny Ludlum Corporation, Pittsburgh, PA (US);
Abstract
A method of pretreating and hot-dip coating aluminum or aluminum alloys on a chromium-containing steel strip to provide an improved coating comprising annealing final gauge steel strip in an oxygen excess atmosphere to produce a chromium-rich oxide on the surface and thereafter electrolytically descaling the strip in an aqueous salt solution to remove the oxide and to expose a chromium depleted surface of the strip. The strip is then transported to a coating line where it is heated to a temperature at or above the temperature of a bath of aluminum or aluminum alloy. A substantially hydrogen atmosphere is maintained over the bath while the dew point is maintained below minus 35.degree. C. The strip is then drawn through the bath to coat the strip.