Armco Inc.

Armco Steel Corporation

Other

Armco Steel Company, L.p.

Alan F Gibson

Frank C Dunbar

Richard A Coleman

Farrell M Kilbane

Marvin B Pierson

Timothy R Roberts

Douglas J Robbins

John C Hogan

David M Smith

Charles Flinchum

Jerry L Arnold

Gayle P Fields

Franklin H Guzzetta

David S Mitch

Wayne G Conley

Continuously hot dip aluminum coated ferritic chromium alloy steel strip. After the steel has been given a pretreatment to remove surface contaminants, the steel is protected in a hydrogen atmosphere until it is passed into the molten aluminum coating metal. The coating metal readily wets the steel surface to prevent uncoated areas or pin holes in the coating layer.

Hot dip aluminum coated chromium alloy steel

Galvannealed electroplated steel strip. The strip is heated to an alloying temperature of at least about 427.degree. C. using an induction coil operated at a frequency to produce an eddy current penetration depth of one-half the strip thickness. The diffusion temperature and time are controlled to minimize the formation of brittle gamma alloy phases in the zinc/iron alloy coating.

Induction galvannealed electroplated steel strip

Producing one-side zinc electroplated strip having enhanced phosphating characteristics. Prior to electroplating, the non-electroplated side of the steel strip is cathodically pickled. Cathodic pickling minimizes staining and etching to the non-electroplated strip surface by the zinc electrolyte during electroplating of the opposite strip surface.

Apparatus for producing one-side electroplated steel strip with enhanced

Method and apparatus for producing one-side electroplated steel strip

A finishing method and apparatus for use in conventional hot-dip coating of the type wherein a ferrous base metal strip, having been appropriately pretreated so as to be at or near the proper coating temperature and so as to have its surfaces free of oxides, is cause to pass beneath the surface of a bath of molten coating metal, exiting the bath between conventional finishing rolls. The method comprises the steps of providing an enclosure which overlies at least the coating metal meniscus areas created between the finishing rolls and the strip, and maintaining within the enclosure an inert or non-oxidizing atmosphere to shroud the meniscus areas. The apparatus comprises the above mentioned enclosure with an appropriate system to provide and maintain the inert or non-oxidizing atmosphere therein.

Finishing method and means for conventional hot-dip coating of a ferrous

Means and a method for reclaiming galvanizing quality zinc alloy from the top dross of a continuous galvanizing line. A dross furnace is provided having front, rear and side walls and a hearth sloping from the rear wall toward the front wall. The front wall is provided with one or more tap holes or a full width slot so sized as to permit the passage of molten zinc alloy therethrough while retaining the resulting sponge or slag. The dross furnace is located with its front wall overhanging the coating pot of the continuous galvanizing line. The dross furnace is maintained at a temperature of from about 460.degree. C. to about 850.degree. C. and is charged with the top dross from the coating pot. The top dross has a residence time in the dross furnace of up to about two hours. The reclaimed galvanizing quality zinc alloy, at yields from about 50% to about 70% based upon the top dross treated, flows directly back into the coating pot. The resulting slag or sponge is removed from the dross furnace which is recharged with top dross.

Means for reclaiming galvanizing quality zinc alloy from continuous

Method for reclaiming galvanizing quality zinc alloy from continuous

A method of preparing the surfaces of steel strip and sheet stock for fluxless hot dip metallic coating, comprising the steps of passing the stock through a first heating section under conditions which form a visible iron oxide layer on the stock surfaces within the color range of dark straw through blue, continuing the heating of the stock in a second heating section isolated from the first heating section in an atmosphere containing less than 5% hydrogen by volume, thereby preserving the oxide layer, and cooling the stock approximately to the temperature of the molten coating metal in a cooling zone containing a reducing atmosphere comprising at least 10% hydrogen by volume, whereby to reduce the oxide layer completely to a metallic iron surface wettable by the coating metal. The radiant energy absorptivity of the steel stock is increased by the formation and preservation of the iron oxide layer in the first and second heating sections.

Method of treating steel strip and sheet surfaces for metallic coating

A method of preparing the surfaces of steel strip and sheet stock for fluxless hot dip coating with molten metal by passing the stock through a first heating zone containing the hot gaseous products of combustion of a sulfur-bearing gaseous fuel with air, continuing the heating in a further heating zone, and cooling the stock approximately to the temperature of the molten coating metal in a reducing atmosphere. The radiant energy absorptivity of the stock is increased by forming a visible sulfur and oxygen rich layer thereon in the first heating zone and preserving the layer throughout the further heating zone. Coke oven gas may be used as fuel in the first heating zone.

Method of treating steel strip and sheet surfaces, in sulfur-bearing

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Middletown, OH, United States of America

Alan F Gibson