Abstract: A method of and apparatus for continuously, evenly and uniformly coating one side only of a moving strip of material, such as steel, with molten zinc or other fluid coating material while effectively preventing the coating material from contacting the opposite side of the moving strip.

Abstract: A process of consistently producing in an economical manner a galvanized steel strip having on one side a thin uniform surface coating of zinc-iron intermetallic compounds containing at least 6 percent iron and being free of metallic zinc and having on the other side a formable metallic zinc surface coating which is formed by continuously immersing the steel strip in a hot-dip zinc coating bath in which the temperature of the steel strip and the coating bath are controlled within a limited range to avoid forming an exclusively thick zinc iron intermetallic layer during hot-dip coating which interferes with good formability of the metallic zinc surface coating and controlling the thickness and uniformity of the zinc coating which is transformed into the coating formed of zinc-iron intermetallic compounds within a range of 10 to 30 g/m.sup.2 while maintaining the variation in coating weight within a range of from 3 to 6 g/m.sup.2 and heating the strip rapidly to a peak temperature of between about 482.degree.

Abstract: A method of producing a hot-dip galvanized steel strip having a uniform zinc-iron alloy coating on one surface and a formable hot-dip metallic zinc coating on the opposite surface which comprises forming a thin uniform hot-dip metallic zinc coating which has a coating weight less than 0.10 ounces per square foot on one side and a heavier metallic zinc coating on the opposite surface and passing the coated strip through a chamber having heating means and cooling means therein, said heating means, such as gas jets, adapted to apply heat directly only to the thin zinc coated side of the strip to convert the thin zinc coating into a fully alloyed zinc-iron coating, and said cooling means, such as air jets, adapted to blow cooling air onto the heavier zinc coating to effect rapid cooling thereof while the thin zinc coated side is being heated; thereby preventing formation of a thick zinc-iron intermetallic subsurface layer on the heavier coated side.

Abstract: Method and means for continuously contact-coating one side only of a ferrous base metal strip with a molten coating metal. One or more roll means are provided to conduct the strip surface to be coated above the surface of a bath of the molten coating metal. The strip surface to be coated is caused to travel sufficiently close to the molten coating metal bath surface that the surface tension and wetting characteristics of the coating metal will permit the formation of a meniscus which will continuously contact and coat the strip surface. The coating is subjected to jet finishing. The strip is maintained in a protective non-oxidizing atmosphere at least until the one side thereof is coated. Alternatively, at least that side of the strip to be coated with the molten coating metal is coated with a flux which remains on the strip until contacted by the coating metal meniscus.

Abstract: A method for finishing molten metallic coatings applied to iron and steel strip by the use of an elongate, laminar flow fluid jet, which jet is used to control thickness and quality of the finished coating.The narrow dimension of the fluid jet is contoured across the strip width to produce the desired coating weight at all parts of the strip and to produce a coated strip edge free from excessively heavy coatings and/or oxide "berries.

Abstract: A ferrous metal strip is continuously hot-dip coated with a zinc-aluminum alloy by immersing the metal strip in a hot-dip coating bath containing between about 0.2 wt. percent and 17 wt. percent aluminum, between about 0.02 wt. percent and 0.15 wt. percent lead, and between about 0.03 wt. percent and about 0.15 wt. percent magnesium with the balance essentially zinc. In a further embodiment the hot-dip alloy coating can also contain between about 0.1 wt. % and 0.3 wt. % copper. The resulting hot-dip zinc-aluminum alloy coatings when applied to a ferrous metal strip exhibit good resistance to intergranular corrosion and blistering when exposed to a high humidity atmosphere and form smooth surface coatings which have good formability both in the "as coated" state and after prolonged storage in a high humidity atmosphere.

Abstract: This method involves impinging fluid against a liquid coating on opposite surfaces of a moving web with the fluid impinging against the liquid coating across the width of the web to control the liquid coating thickness so that on either side of the center of the web there is a component of motion of the fluid toward each associated edge of the web, whereby excess liquid coating on the web has a component of motion toward each edge of the web.

Abstract: A one side plated metal of excellent appearance and quality can be obtained by dipping the material into a plating bath. In this case, one side of the material is oxidized just before it enters the bath so as to form an oxide film on that side and leave it unplated. As soon as it is pulled up from the bath it is maintained under reducing atmosphere so as to prevent adherence of the plating metal to the oxide film.

Abstract: Method and means for continuously contact-coating one side only of a ferrous base metal strip with a molten coating metal. One or more roll means are provided to conduct the strip surface to be coated above the surface of a bath of the molten coating metal. The strip surface to be coated is caused to travel sufficiently close to the molten coating metal bath surface that the surface tension and wetting characteristics of the coating metal will permit the formation of a meniscus which will continuously contact and coat the strip surface. The coating is subjected to jet finishing. The strip is maintained in a protective non-oxidizing atmosphere at least until the one side thereof is coated. The strip may be maintained in the protective non-oxidizing atmosphere until it is sufficiently cooled to prevent the formation of a visible oxide on the uncoated side thereof.

Abstract: A method of finishing a molten metallic coating on metallic strip wherein an elongated subsonic fluid jet, preferably ambient air, is impinged across the molten coating on the upwardly moving strip, the narrow dimension of the jet being increased progressively from the center to each end thereof by contouring the nozzle orifice through which the jet is discharged, adjusting the distance from the nozzle orifice to the strip relative to the narrow dimension of the orifice adjacent the strip edge to satisfy the relation Z.sub.o = .phi.d whereZ.sub.o = distance from orifice to strip.phi. = length of near-field region, expressed as a multiple of dd = narrow dimension of orifice at strip edge,And minimizing the ratio of fluid jet pressure to ambient pressure for a desired minimum coating thickness, whereby to obtain optimum finishing performance and to minimize ripples and edge build-up of coating metal. A high efficiency nozzle is disclosed wherein .phi. = 8 to 10 in the equation Z.sub.o = .phi.d.

Abstract: A partially alloyed galvanized ferrous strand and a method for its production. The method is characterized by the steps of immersing a clean and oxide-free ferrous strand in a molten zinc galvanizing bath to produce on the strand a coating weight of between 0.2 and 0.5 oz. per square foot. After immersion, the zinc-coated ferrous strand is heat treated and cooled to produce a galvanized coating on said ferrous strand, which coating has a duplex structure characterized by an iron-zinc intermetallic layer consisting essentially of the zeta phase, an overlay of free zinc, and an average iron content between about 2 and less than 4% by weight.

Abstract: A ferrous metal strip is continuously hot-dip coated by immersing the metal strip in a hot-dip coating bath containing between about 0.2 wt. percent and about 17 wt. percent aluminum, between about 0.02 wt. percent and about 0.15 wt. percent antimony while excluding lead in amounts more than 0.02 wt. percent, and the balance being essentially zinc. Smooth bright coatings are formed which are highly resistant to intergranular corrosion and blistering when exposed for an extended period to a hot humid atmosphere, have good formability in both the as coated state and after prolonged exposure to a hot humid atmosphere, have a markedly reduced susceptibility to the formation of white rust, and have a reduced rate of general surface corrosion without any diminution of the mechanical properties of the coating.

Abstract: The process described herein involves a method of compacting and increasing the amount of particles, such as polytetrafluoroethylene, etc., deposited in fissures in a surface which involves heating the surface to expand the size of the fissures or pores in the surface, then depositing in the expanded fissures finely divided particles at a temperature at least 100.degree. F, preferably at least 300.degree. F below the temperature of the surface, and subsequently permitting the temperature of the surface and of the particles to come to equilibrium whereby the particles are locked into the fissures by interference fit. The surface is then subjected to a blasting fluid stream carrying finely divided particles applied at a pressure of 30-120 psi, preferably 40-80 psi, to compact the particles in the fissures, after which the original treatment is repeated by heating the surface, depositing additional finely divided particles at a temperature at least 100.degree.

Abstract: A system for controlling the thickness and distribution of a coating applied to a moving substrate includes a pair of "air knives" which discharge pressurized fluid onto a moving substrate as it emerges from a coating bath to screed excess coating from the substrate and leave a coating deposit having a desired thickness and distribution. Each air knife has a plenum chamber which supplies pressurized fluid to a pair of nozzle lips that define an elongated nozzle opening. Fluid flow influencing devices are provided between the plenum and the nozzle lips of each air knife. The flow influencing devices preferably include a baffle plate, a screen assembly, a shutter plate, and a vane assembly. The baffle plate and the screen assembly help assure that a laminar, equally pressurized flow is supplied to the shutter plate.

Abstract: A gas knife process for controlling the thickness profile of hot-dip aluminum coatings, employs a hybrid gas knife design incorporating both a "curved-lip" with a "bow-tie" orifice. This design, in combination with very close knife to strip distance at the strip edges, was found to provide desirable coating profiles. Best results are obtained with knife deflections of 5.degree. to 30.degree. below the horizontal while utilizing orifice pressures of 15 to 70 mm of Hg at line speeds of 20 to 150 m/min.

Abstract: Steel strip at around 1000.degree.F. or higher is run into a galvanizing pot maintained at a higher than conventional temperature to cause alloying of the iron with the spelter on the surfaces of the strip, the strip being passed through a zone of cooled molten spelter before being withdrawn from the galvanizing bath, the steel strip issuing from the bath having an inner iron-zinc alloy coating and an outer molten spelter coating, substantially all the molten spelter coating being removed from at least one surface of the strip by a stream of gas under pressure. Where molten galvanizing spelter coating is left on one side, the weight of the molten layer averages at least 1/10th of an ounce per square foot of coated surface.

Abstract: Objectionable ripple formation in continuous hot-dip coating is avoided by using a single set of blowing nozzles and directing the gas streams downwardly against the strip at an angle between the strip and the center line of the gas stream of from about 0.degree. to about 45.degree., preferably from about 20.degree. to about 40.degree.. The technique is particularly useful at low line speeds of 150 feet per minute or less, especially at high coating weights of 1.5 ounces per square foot or more.