Abstract: A process for coating metal substrates including cleaning, degreasing and activating the substrate wherein a strongly adhering bonding agent layer is deposited on the substrate. The bonding agent layer comprises a thickness of aluminum. The bonding agent layer is deposited at a temperature not exceeding 300.degree. C.

Abstract: A method and composition for coating an automotive brake rotor to render it corrosion resistant without impeding the braking function of the rotor, includes cleaning the rotor and thereafter applying a coating composition thereto which composition includes an inorganic alkali metal-silicate binder and a finely divided metal admixed therewith.

Abstract: A method and apparatus for continuous galvanizing of a linear element wherein controlled flow of molten zinc onto the linear element is effected through one or more nozzles, whereby galvanizing may be accomplished without immersion of the linear element in molten zinc. In a preferred embodiment, the apparatus of the invention comprises an annular nozzle having a central opening through which the linear element is axially advanced. The nozzle is configured to provide a converging, generally frustoconical curtain of molten zinc flowing continuously onto the exterior surface of the linear element.

Abstract: Method and apparatus for meniscus coating one or two sides of steel strip with a metal or metal alloy. The apparatus includes a horizontally disposed coating tray for containing molten coating metal, means for maintaining the temperature of the coating metal above the melting point of the coating metal, means for moving steel strip transversely past a departure lip positioned on one side of the coating tray and means for maintaining the level of the coating metal in the coating tray relative to the upper elevation of the departure lip so that an uninterrupted flow of the coating metal can be delivered over the departure lip to a surface of the strip. The coating tray may be rotatably mounted for adjusting the level of molten metal in the coating tray. The coating tray also may include means for lateral displacement for positioning the departure lip a predetermined distance away from the strip.

Abstract: Upon forming a plating coat on steel works, the works are held in a fluorine- or fluoride-containing gas atmosphere in a heated condition to thereby remove oxidized scales such as SiOx, MnOx and the like on the surface layer of the work and to form a fluoride layer to prevent forming new oxidized scale. The fluoride layer is easily eliminated by an action of added flux to a plating bath or by heating the fluorinated steel works in an atmosphere containing hydrogen prior to dipping in the plating bath to activate the steel surface. The activated steel surface is improved in compatibility with the plating bath and the like to realize a good quality plating coat formation.

Abstract: A hot dip batch coating pot for containing a coating material in a liquid state. The pot comprises a container portion having a horizontal bottom and vertical side walls, with the bottom and said side walls defining an interior volume for containing said coating material. At least one coreless induction furnace is mounted on a side wall of the container portion. The coreless induction furnace defines an interior volume in communication with the interior volume of the container portion for inductively heating the coating material. The coreless induction furnace is disposed at an angle to the vertical.

Abstract: A shallow vessel (50,52) for being horizontally disposed when containing a molten metal or metal alloy (66) for meniscus coating one side of a clean metal strip (34A) when the strip is moved vertically past one side of the vessel. The vessel includes a shell (68) such as austenitic stainless steel, a refractory lining (70), a molten metal departure lip (72) mounted on the upper surface of the side of the vessel, a spirally shaped induction coil (64) for maintaining the molten metal above its melting point and a flux concentrator (74). The induction coil is positioned below the refractory lining and the flux concentrator is positioned below the induction coil. The induction coil and the flux concentrator underlie the area occupied by the molten metal.

Abstract: A method for producing ultra-high strength galvanized steel strip from a martensitic, plain carbon, steel strip which is pre-treated by induction heating rapidly or by fluxing, then hot dip galvanized and tempered, and then cooled to stop further tempering. The resulting galvanized steel strip has a microstructure comprising tempered martensite, a tensile strength substantially greater than 120,000 psi (827 MPa) and a coating weight substantially greater than 30 g/m.sup.2 /side.

Abstract: A method of producing an aluminum tube covered by a layer of zinc using a continuous cold forming machine which includes the steps of: providing an extrusion die having a heating device and an inert gas-blowing tube to the cold forming machine, introducing an aluminum prime wire to the cold forming machine, extruding the prime wire through the extrusion die to form an aluminum tube while heating the die to a high temperature and blowing an inert gas across the die toward the tube to provide a high-temperature, non-oxidized aluminum tube, and flame spraying zinc powder onto the outer non-oxidized surface of the tube to cover the surface and provide an anticorrosive layer of zinc on the aluminum tube.

Abstract: A continuous process for coating a series of workpieces with a metal coating comprises the steps of cleaning the workpieces with a high-pressure water system which utilizes particulates; isolating the workpieces in a non-oxidizing chamber; spraying the workpieces with a wet flux; inductively preheating the workpieces with a preheat induction coil; spraying a coating metal onto the surface of the workpieces; inductively heating the workpieces with a main induction coil; and continuously conveying the workpieces through each of the above steps.

Abstract: This invention includes a method featuring steps having a transport (64, 68) to carry metal articles (10, 14) through a vacuum chamber (62, 66, 90) containing a plasma cleaning station (32) followed by exposure to an evaporant of metal (42) generated by an E-Beam (50) caused to condense on the articles in high vacuum. A channel structure (51) is provided to cause selective condensation upon the surface of said articles. The apparatus includes several stations (101, 102, 103) to provide multiple coatings on one or both sides of an article to be coated.

Abstract: There is disclosed a process for preparing alloyed-zinc-plated steel sheet having excellent deep drawability, which comprises adjusting the temperature of substrate steel sheet of titanium-killed steel essentially consisting of C.ltoreq.0.01%, Si<0.15%, Mn: 0.15-0.85%, Ti: 0.05-0.30%, P.ltoreq.0.02%, S.ltoreq.0.02%, Al.ltoreq.0.05% and balance of Fe, to a temperature within a temperature range T(.degree.C.) defined as 180.ltoreq.T.ltoreq.-240.times.W+292, wherein W(%) is the Ti content of the substrate steel sheet, subjecting said steel sheet to Zn-plating by vacuum vapor deposition, and thereafter maintaining the plated steel sheet for alloying the plating zinc layer and the substate steel at 220.degree..about.320.degree. C. for 1-50 hours in accordance with Ti content of the substrate steel. This process provided alloyed zinc-plated steel sheets having excellent drawability and powdering resistance.

Abstract: Aluminum is flow-coated onto ferrous strip by reducing the hot strip in hydrogen, cooling it to 650.degree.-680.degree. C. in nitrogen and spraying molten aluminum on it such that the aluminum splats flow into each other but solidify in 0.2-0.5 seconds. The aluminum is bonded to the strip through an intermetallic layer less than quarter of the total coating thickness, the aluminum having a cast structure.

Abstract: A method and apparatus for uniformly cladding a metal wire with a coating of a second metal is provided. The metal wire to be coated is preheated in a non-oxidizing atmosphere to a temperature slightly less than the melting point of the metal coating. The metal coating is present as a molten metal in an atomization chamber. A source of preheated, pressurized, non-oxidizing gas is utilized to inject such gas into spray nozzles. Each spray nozzle also receives molten metal that is drawn into and atomized in the nozzle. The molten metal is thusly sprayed onto the metal wire moving through the atomization chamber.

Abstract: A differentially coated, galvanized steel strip is produced by hot dip coating both sides of a steel strip and adjusting the weight of coating metal on opposite sides of the strip to produce a light coated side and a heavy coated side. The strip is then precooled to fully solidify the heavy coated side following which the galvanized strip is subjected to a treating step in which simultaneously the light coated side is heated and the heavy coated side is cooled. This fully transforms the light coated side to iron-zinc alloy throughout while only partially transforming an inner layer on the heavy coated side to iron-zinc alloy. The outer layer on the heavy coated side consists entirely of coating metal, and there are no intermittent bleed-throughs of iron-zinc alloy to the outer surface of the heavy coated side.

Abstract: 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.

Abstract: The present invention relates to a continuous coating process by a layer of Zn, Al or of a Zn-Al alloy for a cold laminated steel band comprising a heating thermic cycle, followed by a rapid cooling, a tempered coating in the metal bath of coating in fusion, at a temperature from 460.degree. to 500.degree. C., and a subsequent cooling, characterized in that after the tempered coating, the coated steel band is subjected to an over-aging treatment by maintaining the band at a temperature comprised between 430.degree. and 270.degree. C. during at least two minutes.This process is carried out in an installation comprising an over-aging chamber.

Abstract: The coating device comprises a furnace (1) comprising a crucible (4) and a lateral distribution conduit (3) whose outlet communicates with an externally open release aperture (2) serving to distribute the molten metal over the entire width of the metal strip (6) to be coated. This strip (6) is entrained from a supply spool (7) to a storage spool (8) and passes over a positioning roll (10) mounted opposite to the release aperture (2), the spacing between this roll and the edge of the release aperture being adjustable by means of a screw (15). A bank of burners (16) is located opposite to the reverse of the strip (6) and upstream of the release aperture (2) in order to heat the strip before it passes in front of the release aperture (2). A molten metal bath is thus constantly maintained between this release aperture (2) and the face to be coated of the strip (6) which is covered with a layer of metal during its displacement.

Abstract: The molten exterior surface portion of a hot dip galvanized steel strip is solidified after the strip is withdrawn from a bath of molten zinc by spraying finely divided particles of a liquid nucleating agent for initiating solidification. The particles are sprayed into an electrostatic field alongside the strip. The particles are initially directed along a path which avoids impingement against the strip. However, the smaller particles are attracted to the strip under the influence of the electrostatic field, to initiate solidification. The larger particles have a momentum along their path large enough to resist the influence of the electrostatic field, thereby permitting the larger particles to continue along a path which avoids impingement. This minimizes the formation of undesirably large spangles and an undesirable surface appearance on the strip.

Abstract: An improved method of and apparatus for hot dip metal coating of steel strip in which the strip is heated and cleaned in a furnace then passed through a protective hood containing a reducing gas and into the molten coating metal bath. Coating metal oxides evolved in the hood are removed by flowing a nonoxidizing gas across the surface of the coating metal in the hood and withdrawing the gas and entrained oxides from a location in the vicinity of the coating metal surface. The oxides are removed from the withdrawn gas, and the gas returned to be again flowed across the coating metal surface.

Abstract: A method of fabricating composite metal wires such as aluminium clad steel wires is disclosed which comprises providing a core of hard metal with a cladding of soft metal by extrusion. In fabricating a composite metal wire by extrusion, a core is generally aligned, polished, cleaned or otherwise pretreated before entering an extruder so that a high and variable tension is imparted to the core. By avoiding such tension variation and maintaining the core under a constant low tension and by electrically heating the core before the core enters the extruder, a composite metal wire of improved quality is fabricated in a stable manner.

Abstract: A system for the treatment of continuous metal webs facilitates both continuous annealing and hot-dip coating operations interchanging from annealing to a combined annealing and coating, and vice-versa. The system has an annealing station common to both operations as well as web feed and discharge sections and web entry storage and web discharge storage stations associated therewith.

Abstract: In a case where filament-like articles (e.g. wires) are dip-coated by upwardly passing the article into a bath of molten metal through the bottom and top vertical openings of a spout containing the molten metal, the article to be coated is wrapped, before it enters the bottom inlet opening in the spout, with a blanket of protective gas at a pressure sufficient to cause the gas to penetrate into the spout simultaneously with the article, to progressively and regularly circulate around the molten metal and to steadily emerge from the upper opening of the spout still effectively shielding the freshly coated article.

Abstract: This invention relates to a process of selective galvanizing of materials adapted to be galvanized by immersion in hot conditions characterized by the application on said materials, prior to immersing them into a bath of melted zinc, on those spots on which no galvanizing is desired, calcium carbonate alone, or a mixture thereof with an alkali metal chlorinated-s-triazine trione, or with an alkali metal salt of an oxygen-containing chlorine compound.

Abstract: A dual-purpose production plant for cold rolled steel sheets and hot-dip galvanized steel sheets having, successively disposed in series, a heating zone, a soaking zone, a primary cooling zone, an overaging zone equipped with a controlled cooling facility, a molten galvanizing zone, an intermediate cooling means, a secondary cooling zone, a temper rolling means, and a chemical treatment means, and a bypass for directly connecting the overaging zone and the secondary cooling zone with each other.

Abstract: Metallic articles, for instance, ferrous strips are metallized, for instance, zinc coated by passing the heated article through a coating chamber and applying thereto a continuous stream of the molten coating metal so as to uniformly and evenly metallize said article. Thereafter, excess molten coating metal is removed from the coated article by hot gas blasting and the hot gas blasted article leaving the coating chamber is immediately cooled. Wiping means may be provided before applying the molten coating metal so as to deflect any molten coating metal dropping from the metallic article passing therethrough, while rollers may be arranged between the coating metal applying means and the hot gas blasting means. Said rollers serve to remove the major part of excess coating metal from the coated metallic article and to stabilize movement of the metallic article passing through the coating chamber.

Abstract: A finishing method and apparatus for conventional continuous hot-dip coating of the type wherein a ferrous base metal strip is caused to pass beneath the surface of a coating bath of molten coating metal and is thereafter subjected to jet finishing, the ferrous base metal strip having been appropriately pretreated so as to be at the proper coating temperature and so as to have its surfaces oxide-free when passing through the bath of molten coating metal. The method comprises the steps of providing an enclosure for the two-side coated strip as it exits the coating bath, locating a finishing jet nozzle to either side of the coated strip within the enclosure, jet finishing the coated strip with a non-oxidizing or inert gas. The apparatus comprises the above mentioned enclosure with the jet finishing nozzles located therein and an appropriate system to provide a non-oxidizing or inert atmosphere within the enclosure.

Abstract: Steel strip is dipped in a molten metal bath (e.g. Al-Zn) maintained at above 500.degree. C., cooled to solidify the metal coating, and then cooled to below 475.degree. C. by an intense and rapid cooling operation which does not impair the flatness of the strip, e.g. immersion in a hot aqueous bath or spraying a mist. Before hot-dipping, the steel strip is preferably recrystallisation annealed and cooled to a temperature not lower than that of the molten metal bath.

Abstract: Seafood pots made of wire mesh netting are prepared for galvanizing by first passing them through an incineration chamber to burn, melt and loosen foreign material thereon, and then passing them through a high pressure liquid spray to remove residual burned matter and loosened foreign material. The pots are then ready to be passed through the steps of the galvanizing process, which includes dipping the pots into heated preflux before they are dipped into molten zinc. An inverted drying chamber bridges the distance between the preflux tank and the zinc kettle, through which the seafood pots are moved by conveyor means to dry the preflux, with drying heat within the chamber being drawn from the tank and the kettle. The seafood pots are vibrated as they are withdrawn from the molten zinc to effect an even coating of zinc on the wire mesh netting thereof.

Abstract: A plating chamber holds a reducing or inert atmosphere heated to a temperature suited for plating or galvanizing. A pair of power-driven coating rolls are horizontally disposed in the plating chamber, one roll contacting the top surface of a metal strip to be plated and the other contacting the bottom surface. A molten coating metal is continuously supplied so as to form a uniform film of the metal on the peripheral surface of each coating roll. By means of deflector rolls horizontally disposed in the plating chamber, a metal strip heated to a temperature suited for plating continuously travels through the chamber. A surface of the strip becomes plated on contacting the peripheral surface of the coating roll on which the film of the molten coating metal has been formed. The coating rolls can be drawn away from the surface of the strip by shifting the deflector or coating rolls, so that plating can be applied to one, both or neither side of the strip as desired.

Abstract: A process of hot-dip coating a strip of cold rolled low carbon steel having as an essential alloying element at least one strong oxide forming metal, such as titanium, aluminum, silicon or chromium or a combination thereof, to overcome the difficulty of uniformly hot-dip coating such steels with aluminum and other protective metals on a Sendzimir-type hot-dip coating line wherein the steel strip is thoroughly cleaned by washing in an alkaline cleaning solution, brushing and drying to remove metallic particles and non-metallic contaminants, forming a dry film coating on a clean dry surface of the strip of a higher fatty acid amide having from 8 to 18 carbon atoms, heating said strip to a temperature sufficient to completely volatilize said amide film coating, passing said strip through a heating zone containing a reducing atmosphere in which the strip is heated to a temperature of at least about 704.degree. C. (1300.degree. F.

Abstract: A steel sheet having a zinc coating on one side and a uniformly alloyed layer of iron and zinc on the other side, the amount of the alloyed layer being from 0.001 g/m.sup.2 to 1 g/m.sup.2 of zinc and containing from 6 to 20 percent by weight iron.

Abstract: A continuous cleaning and preheating system for steel strip to be annealed prior to being coated or otherwise treated wherein controlled reducing steps are employed to remove surface contaminants from the strip, which system uses direct flame heating whereby the combustion gases from open flame burners within a closed furnace flow into and along a restricted elongated tubular zone so that the gases are in direct contact with the strip as it enters and passes through the tubular zone and the furnace in a direction countercurrent to the flow of the said gases.

Abstract: A process and apparatus for coating only one side of a metal strip with a molten metal, by continuously conveying a cleaned and heated strip of metal through a protective gas atmosphere above the level of a melting bath of the molten metal. The metal strip is supported on a reverse side thereof in the area of contact with the molten metal, and with the obverse side of the strip out of contact with the bath itself. The molten metal is conveyed by means of a scoop roller towards the supported area of the strip and only the scoop roller is immersed in the melting bath and only for a part of its surface area.

Abstract: In a line for coating a ferrous base metal strip with a molten coating metal, the line being of the type having a preparation furnace for the strip comprising a direct fired furnace, a controlled atmosphere heating furnace, one or more cooling chambers and a snout leading beneath the surface of the molten coating metal bath, all in sealed relationship to each other, the improvement comprising a method and means for maintaining a non-oxidizing atmosphere at positive pressure within the entire preparation furnace during line stops. To this end, a retractable, refractory lined door means is provided in the conduit between the direct fired furnace and its exhaust fan to seal off the direct fired furnace from its exhaust fan and an air dilution opening in that conduit. Additionally, means are provided to add excess nitrogen flow to the preparation furnace to maintain a positive pressure therein.

Abstract: Sealing means for preventing metal vapor, and in particular zinc vapor, evolution from the surface of a bath into a furnace is provided at the exit end of the heat processing industrial furnace through which a continuous metal sheet is advanced. Upon exiting the furnace the metal sheet is dipped into a bath for hot dip coating thereof. At the zone of the industrial furnace from which the continuous metal sheet exits the furnace and advances into the coating bath, there is provided therein an atmosphere having a low dew point and a relatively high hydrogen content to thereby reduce the oxidation of the metal vapor which may have migrated into the furnace. Furthermore, sealing means are provided between zones of the furnace to retain the integrity of this atmosphere, and thus isolating zones having different atmosphere compositions.

Abstract: Metallic articles, for instance, ferrous strips are metallized, for instance, zinc coated by passing the heated article through a coating chamber and applying thereto a continuous stream of the molten coating metal so as to uniformly and evenly metallize said article. Thereafter, excess molten coating metal is removed from the coated article by hot gas blasting and the hot gas blasted article leaving the coating chamber is immediately cooled. Wiping means may be provided before applying the molten coating metal so as to deflect any molten coating metal dropping from the metallic article passing therethrough, while rollers may be arranged between the coating metal applying means and the hot gas blasting means. Said rollers serve to remove the major part of excess coating metal from the coated metallic article and to stabilize movement of the metallic article passing through the coating chamber.

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 galvanized ferrous article having an adherent, ductile and highly corrosion resistant coating of galvanizing alloy which presents a matted surface which is free or substantially free of spangle and which is capable, upon application of a paint coating thereon, of strongly anchoring the paint coating to the galvanized coating, said galvanizing alloy comprising a zinc base alloy containing 3-10% preferably 3.5-10% by weight of aluminum and one or more elements of magnesium, calcium, beryllium, titanium and copper in amounts within the range specified in terms of the total weight of the lead and tin contained in the galvanizing alloy.

Abstract: In a line for coating a ferrous base metal strip with a molten coating metal, the line being of the type having a preparation furnace for the strip comprising a direct fired furnace, a controlled atmosphere heating furnace, one or more cooling chambers and a snout leading beneath the surface of the molten coating metal bath, all in sealed relationship to each other, the improvement comprising a method and means for maintaining a non-oxidizing atmosphere at positive pressure within the entire preparation furnace during line stop. To this end, a retractable, refractory lined door means is provided in the conduit between the direct fired furnace and its exhaust fan to seal off the direct fired furnace from its exhaust fan and an air dilution opening in that conduit. Additionally, means are provided to add excess nitrogen flow to the preparation furnace to maintain a positive pressure therein.

Abstract: A drawing quality hot-dip coated low carbon aluminum killed steel strip produced by conventional steel strip forming and continuous hot-dip coating procedures wherein the hot rolled coiling temperature is maintained within a temperature range of 1250.degree. F. - 1300.degree. F. and the cold rolled steel strip is continuously heat treated on a Sendzimir-type continuous hot-dip coating line at a temperature of between 1850.degree. F. and 1950.degree. F. before cooling the strip to about the temperature of the hot-dip coating bath and immersing the strip in a hot-dip galvanizing or aluminum coating bath followed by conventional annealing. The microstructure of the drawing quality hot-dip coated steel strip is characterized by spaced islands formed of fine pearlite and fine ferrite having a grain size of about ASTM 9-10 surrounded by areas of large ferrite grains having the grain size of about ASTM 7.5-8.

Abstract: Steel strip is first heated to a predetermined temperature suitable for imparting desired properties to the strip and is then immersed in an aqueous bath maintained at substantially its boiling temperature. The composition of the aqueous bath is preferably adjusted to ensure the formation of an oxide film on the entire surface of the strip. After the strip has been withdrawn from the bath, oxide is eliminated from at least part of the surface of the strip, e.g., from one or both faces, by removal of the oxide or by reduction of the oxide. Simultaneously or subsequently, the strip is heated to a given temperature, e.g., 420.degree.-550.degree. C., maintained at this temperature, and immersed at this temperature in molten zinc.

Abstract: A process for simultaneously preheating and preparing a ferrous surface, prior to the depositing thereon of galvanized zinc coatings, replaces conventional fluxing techniques with the step of immersing a ferrous object in a bath of a molten salt or salts. The salts are chosen so that they are liquid at a temperature below that of the zinc coating step. The liquid acts as a non-fuming flux and preheat for the surface. Particular salts include metallic hydroxides and halides.

Abstract: A method of surface treatment of aluminum-killed and low alloy steel strip and sheet for fluxless hot dip metallic coating which comprises heating the steel in a furnace atmosphere containing the hot gaseous combustion products of air with a sulfur bearing gaseous fuel including 5 to 1600 grains of sulfur per 100 cubic feet of fuel wherein the atmosphere includes sulfur compounds and from about 6% free oxygen to about 7% by volume excess combustibles whereby to form a sulfur and oxygen rich film on the steel surfaces, passing the steel into a further heating section wherein it is brought to a maximum temperature of about 593.degree. to about 927.degree. C. in a reducing atmosphere containing at least 10% hydrogen by volume, passing the steel into a cooling section having an atmosphere containing at least 10% hydrogen and the balance nitrogen whereby to reduce the sulfur and oxygen rich film to a metallic iron surface, and cooling the steel approximately to the temperature of the molten coating metal bath.

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: Anti-plating agents which form, after heated, compounds having a composition of(0.5-9.0)M.sub.2 O.SiO.sub. 2.(0.1- 7.2)B.sub.2 O.sub.3.(1.0- 34.5)MgOwherein M represents an alkali metal, are disclosed. An anti-plating film formed on the surface of a steel sheet by the use of the agent is excellent in the property for preventing the sheet from being plated and in the peeling property from the sheet, and the agents are suitable for production of one-side hot-dip plated steel sheets.

Abstract: 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.

Abstract: 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.