Armco Inc.

Armco Steel Company, L.p.

Steven L Boston

Richard A Coleman

Jerry L Arnold

Forrester Caudill

William R Seay

Farrell M Kilbane

Thomas A Compton

David S Mitch

Lloyd W Abrams

Danny E Lee

Continuous hot dip aluminum coated ferritic chromium alloy steel strip. Strip is cleaned by heating to a temperature no greater than about 650.degree. C. in a direct fired furnace. The cleaned strip is further heated in a protective atmosphere containing at least 95% by volume hydrogen, cooled in the protective hydrogen atmosphere to near or slightly above the melting point of an aluminum coating metal, and passed into a bath of the aluminum coating metal. The low direct fired furnace cleaning temperature and hydrogen protective atmosphere provides good wetting of a chromium alloy steel surface to prevent uncoated areas or pin holes in the aluminum coated layer.

Hot dip aluminum coated chromium alloy steel

A process for suppressing zinc vapor in the snout of a continuous line for hot dip coating one side or both sides of a ferrous base metal strip with a molten zinc or zinc based alloy by maintaining the atmosphere within the snout to include about 1-8% hydrogen by volume and about 300 ppm to 4500 ppm water vapor with the balance being one or more inert gases, such as nitrogen. The atmosphere has a hydrogen/water vapor ratio of at least 4 to 1, or higher. This atmosphere is oxidizing to zinc vapor but non-oxidizing to the ferrous strip.

Process for controlling snout zinc vapor in a hot dip zinc based coating

A process for controlling zinc vapor in a finishing process for a hot dip zinc based coating on a ferrous base metal strip in which the strip emerges from the coating bath into an enclosed chamber, by injecting high dew point gas into the chamber. The process is applicable on both a one side and two side coating process. Preferably the atmosphere has about 1-3% water vapor, by volume, for both one-sided and two-sided process.

Process for controlling zinc vapor in a finishing process for a hot dip

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Middletown, OH, United States of America

Steven L Boston