US3112213A - Differentially coated galvanized strip - Google Patents

Differentially coated galvanized strip Download PDF

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US3112213A
US3112213A US862082A US86208259A US3112213A US 3112213 A US3112213 A US 3112213A US 862082 A US862082 A US 862082A US 86208259 A US86208259 A US 86208259A US 3112213 A US3112213 A US 3112213A
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strip
coating
zinc
ferrous
metal
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US862082A
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Lusa George
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Armco Inc
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Armco Inc
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Priority to US862082A priority Critical patent/US3112213A/en
Priority to GB42739/60A priority patent/GB904485A/en
Priority to US256530A priority patent/US3177053A/en
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/003—Apparatus
    • C23C2/0038—Apparatus characterised by the pre-treatment chambers located immediately upstream of the bath or occurring locally before the dipping process
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/003—Apparatus
    • C23C2/0038—Apparatus characterised by the pre-treatment chambers located immediately upstream of the bath or occurring locally before the dipping process
    • C23C2/004—Snouts
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/006—Pattern or selective deposits
    • C23C2/0062—Pattern or selective deposits without pre-treatment of the material to be coated, e.g. using masking elements such as casings, shields, fixtures or blocking elements
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/922—Static electricity metal bleed-off metallic stock
    • Y10S428/9335—Product by special process
    • Y10S428/939—Molten or fused coating
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12639—Adjacent, identical composition, components
    • Y10T428/12646—Group VIII or IB metal-base
    • Y10T428/12653—Fe, containing 0.01-1.7% carbon [i.e., steel]

Definitions

  • the invention relates to galvanized, i.e. zinc coated, ferrous strip or sheet materials bearing on one side a standard or heavy-weight zinc coating, and on the other side a coating which, while derived from zinc, is very much thinner.
  • a wiper blade on one side of the strip above a standard exit roll will serve to wipe off almost all of the coating resident on that side of the strip.
  • the blade may be made of metal or any other substance of sufficient strength and capable of withstanding the heat involved.
  • one side of the galvanized product may be given an organic coating of paint, enamel or other material, while it is desirable to have the other side carry a standard or heavy galvanized coating. If the organic coating can be made to adhere to a very thin zinc layer upon the one side of the product, it will obviously not be necessary for both sides of the product to carry heavy or standard zinc coatings.
  • ice metal of this invention is useful for such parts.
  • the external finish of the body will adhere very well to the thinly coated side of the product of the invention, which is located outwardly, while a full single coating on the inner side will protect that side from corrosive influences.
  • the principal object of the invention is the provision of a new galvanized product and a method of making it, which avoids all of the difficulties mentioned above.
  • This object, and others which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications, is accomplished by that procedure and in that product of which certain exemplary embodiments will now be described.
  • the drawing is a diagrammatic representation or flow sheet of one mode of carrying on the process.
  • the galvanized sheets are preferably formed from strip stock which has been galvanized in accordance with the teachings of the Sendzimir U.S. Patent No. 2,197,622.
  • cold rolled strip 1 is first passed through an oxidizing furnace 2 in which oils, greases, carbonaceous smudges, and other non-reducible materials are removed from their surfaces, and a thin, controlled coating of oxide is formed thereon.
  • the strip is next led into a reducing furnace 3 wherein the thin coating of oxide is completely reduced.
  • the temperature in the reducing furnace may, if desired, be sufficient to anneal the stock.
  • the strip passes through a cooling hood 4 in which it is still protected by reducing gases, and thence is carried as at 5 beneath the surface of a pot 6 of molten galvanizing metal 7 the entrance end of which is flux-free.
  • the strip has a very short path of travel through the galvanizing pot.
  • Zinc metal in the pot contains a small proportion of aluminum. All of these conditions combine to produce a galvanized product in which the interface alloy is extremely thin. It is believed to be due largely to this factor that the galvanized product is characterized by extraordinary ductility and adherence of the coating, so that the coating can withstand substantially any bending, forming, drawing, or other working operations which can be performed on the base stock. A heat treatment which would result in an increase in the thickness of the interface alloy would, to a considerable extent, iznpair the ductility and adherence of the galvanized coating.
  • the new product therefore, is a sheet or strip which has a standard or heavy zinc coating upon one side, the characteristics of which have not been affected, and upon the other side a very thin layer of zinc alloyed with the ferrous base metal. Such a product has never before been produced.
  • the pretreatment of the strip and the coating are carried on as is usual in the practice of the Sendzimir patent to which reference has been made.
  • the exit rolls may be grooved in such a way as to apply coatings of different thicknesses to opposite sides of the strip, or an air blast may he used on the meniscus on one side, as mentioned above.
  • These expedients are not necessary.
  • the use of a scraper blade 9 is the preferred procedure, the blade being so located as to deflect the strip as shown and insure contact all across its Width. A blade properly used will be effective in removing the major portion of the zinc galvanizing metal on the side of the strip contacted by it.
  • the zinc coating on the opposite side of the strip does not constitute a limitation on the invention.
  • the heavy coating can be as heavy as that normally produced commercially, which could be as much as one ounce or heavier, per square foot.
  • the other, or light side, the strip can have coatings as light as .1 ounce, or less, per square foot.
  • the heat applied to the wiped side of the strip is conveniently produced by one or more gas ribbon burners It or some other suitable heat source, such as an electrical heating means. Assuming that the strip leaves the coating pot in a vertical direction, the burners will be placed in a horizontal position extending across the strip. The exact position of the burners with respect to the exit rolls is not critical; and it has been found that the burners may vary from about one foot to ten feet from the exit rolls. The burners will be located at such a distance from the surface of the strip as to produce the proper heat at that surface. In general, the burners will lie from 2 inches to 8 inches away from the strip. The heat may vary from 500 F. to about 1400 F. at the surface of the strip.
  • the heating should be done in such a way that, while the adjacent and thinly coated surface of the strip is heated to the desired temperature, the rate of heat dissipation from the strip as it cools in air will prevent the transmission of any great degree of heat to the opposite side of the strip.
  • the temperature may be varied in accordance with the thickness of the zinc coating remaining on the wiped side of the strip, and the amount of heat required to cause it to alloy with the base metal.
  • the pot temperature may be raised as high as about 870 F. without essentially affecting the characteristics of the standard or heavy zinc coating upon the one side of the sheet.
  • a process of making a differentially coated galvanized stock which comprises forming zinc coatings of unequal thickness on opposite sides of a ferrous sheet stock, and subjecting the sheet stock upon the side hearing the coating of lesser thickness briefly to localized heat sufficient to alloy the zinc on the said last mentioned side substantially entirely with the ferrous sheet stock, while leaving substantially unaffected on the opposite side of the sheet both the layer of zinc coating metal thereon and any interface alloy existing between said layer and the base metal.
  • a process of producing a differentially coated galvanized ferrous sheet product which comprises subjecting ferrous strip to a cleaning and oxidizing operation so as to form thereon a thin uniform film of oxide, passing the strip so treated through a reducing furnace and heatiug it therein in the presence of reducing gases so as thoroughly to reduce the said oxide layer, and through a cooling hood containing reducing gases so as to introduce it into a bath of molten zinc coating metal through a flux free surface thereof, withdrawing the said st.” from said bath through exit rolls, scraping one surface of said strip above one of said exit rolls so as to remove the greater part of the coating of zinc coating metal thereon, and then subjecting the same side of said strip to localized heat to cause the remaining zinc thereon to alloy with the ferrous strip surface without essentially affecting the coating of zinc coating metal or the opposite side of said strip.
  • a process of making a differentially coated galvanized stock which comprises passing ferrous strip through a bath of molten coating metal of which the primary constituent is zinc, under conditions to cause the said molten coating metal to cling to and coat the surfaces of the said ferrous strip, and upon withdrawal of the ferrous strip from the bath of molten coating metal treating the surfaces thereof so that the resident layer of coating metal upon one side of it is substantially thicker than the coating thereof upon the other side, and after the said treatment applying localized heat to the thinner coating upon the last mentioned side of said ferrous strip so as to cause the said coating metal in the said thinner coating to alloy substantially entirely with the ferrous strip, while leaving subtsantially unaffected upon the opposite side of said strip both the thicker layer of coating metal thereon and any interface alloy existing between said layer and the base metal.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Coating With Molten Metal (AREA)

Description

Nov. 26, 1963 G. LUSA DIFFERENTIALLY COATED GALVANIZED STRIP Filed Dec. 28, 1959 rlo V INVENTOR GEORGE LUSA,
,mw, PM
ATTORNEYS United States Patent 3 112,213 DIFFERENTIALLY CATED GALVANIZED STRIP George Lusa, Dayton, Ohio, assignor to Armco Steel Corporation, Middletown, Ohio, a corporation of Qhio Filed Dec. 28, 1959, Ser. No. 862,082 6 Claims. (Cl. 117-51) The invention relates to galvanized, i.e. zinc coated, ferrous strip or sheet materials bearing on one side a standard or heavy-weight zinc coating, and on the other side a coating which, while derived from zinc, is very much thinner.
It has hitherto been realized that there are various uses for a galvanized product having a heavy or standard coatmg upon one side and a lighter coating upon the other. Forexample, when galvanized sheets are used for roofing or siding on buildings, the heavy weights of coating are needed on the exterior to secure a long life and resist corrosion when exposed to the weather; but the inside surface of such sheets, not being exposed to the elements, do not require such a heavy weight of coating.
Various suggest-ions have been made in the past looking toward the provision of differentially coated galvanized sheets or strip. In the coating operation, the ferrous material is passed through a bath of molten zinc and emerges therefrom between exit rolls which are grooved to control the extent and uniformity as well as the thickness of the coating. It has been found that the exit roll on one side of the strip may be grooved in such a way as to leave a lesser weight of coating on the strip surface at that side. Again, it has been disclosed in the copending application of Whitley, Kemplin and Jones, Serial No. 733,708, filed May 7, 1958, now Pat. No. 2,992,941, and entitled Exit Machine for Coating Apparatus and Method of Cont-rolling Coating Thickness, that the use of an air blast on the meniscus at the exit rolls can decrease the amount of coating metal which is applied or left on the surface of the strip. The meniscus, of course, refers to that quantity of zinc which collects above an exit roll and between it and the surface of the strip as it is leaving the exit roll.
It has also been found that the use of a wiper blade on one side of the strip above a standard exit roll will serve to wipe off almost all of the coating resident on that side of the strip. The blade may be made of metal or any other substance of sufficient strength and capable of withstanding the heat involved.
One ditficulty with the formation of differentially coated galvanized strip lies in the fact that the wiped or otherwise more thinly coated side of the material is likely to have a streaked and unsightly appearance. While this may make no difference in certain uses, where the thinly coated side of the product is exposed to View, it will usually be desired to have it covered with paint or enamel. Zinc coatings as usually produced are not very receptive to coatings of paint and enamel unless they are given pretreatmentsv These pretreatments are generally expensive and involve the installation of fairly bulky apparatus.
In still other uses, one side of the galvanized product may be given an organic coating of paint, enamel or other material, while it is desirable to have the other side carry a standard or heavy galvanized coating. If the organic coating can be made to adhere to a very thin zinc layer upon the one side of the product, it will obviously not be necessary for both sides of the product to carry heavy or standard zinc coatings. As an example of one such use, there are ceretain sheet metal parts of an automobile body, such as the so-called rocker panels, where the outer surface will be covered and protected with the ordinary automobile finish, but where the inner surface is exposed to air, moisture, and other corrosive influences but cannot readily be painted or otherwise protected. The sheet 3,l l2,2l3 Patented Nov. 26, 1963 ice metal of this invention is useful for such parts. The external finish of the body will adhere very well to the thinly coated side of the product of the invention, which is located outwardly, while a full single coating on the inner side will protect that side from corrosive influences.
Another problem is involved in the use of galvanized sheets on the under sides of automobiles. It is usual to spot weld adjacent panels together; but the standard zinc coatings cause a considerable amount of build-up on the copper welding electrode tips. This impedes the welding operation and makes for a frequent cessation of the Work so that the electrode tips may be cleaned.
The principal object of the invention is the provision of a new galvanized product and a method of making it, which avoids all of the difficulties mentioned above. This object, and others which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications, is accomplished by that procedure and in that product of which certain exemplary embodiments will now be described.
The drawing is a diagrammatic representation or flow sheet of one mode of carrying on the process.
The copending application of Schnedler, Serial No. 753,015, filed August 4, 1958, now Pat. No. 2,986,808, teaches that a zinc coated sheet, which has been subjected to a heat treatment so as to cause an increase in the thickness of the interface alloy, will be usefully increased as to its acceptance of paints and enamels while still having a surprising amount of corrosion resistance. However, it is not generally advantageous to increase the extent of the interface alloy on both sides of the sheet for reasons which will now be set forth:
The galvanized sheets are preferably formed from strip stock which has been galvanized in accordance with the teachings of the Sendzimir U.S. Patent No. 2,197,622. In the practice taught by this patent, cold rolled strip 1 is first passed through an oxidizing furnace 2 in which oils, greases, carbonaceous smudges, and other non-reducible materials are removed from their surfaces, and a thin, controlled coating of oxide is formed thereon. The strip is next led into a reducing furnace 3 wherein the thin coating of oxide is completely reduced. The temperature in the reducing furnace may, if desired, be sufficient to anneal the stock. From the reducing furnace, the strip passes through a cooling hood 4 in which it is still protected by reducing gases, and thence is carried as at 5 beneath the surface of a pot 6 of molten galvanizing metal 7 the entrance end of which is flux-free. The strip has a very short path of travel through the galvanizing pot. Zinc metal in the pot contains a small proportion of aluminum. All of these conditions combine to produce a galvanized product in which the interface alloy is extremely thin. It is believed to be due largely to this factor that the galvanized product is characterized by extraordinary ductility and adherence of the coating, so that the coating can withstand substantially any bending, forming, drawing, or other working operations which can be performed on the base stock. A heat treatment which would result in an increase in the thickness of the interface alloy would, to a considerable extent, iznpair the ductility and adherence of the galvanized coating.
It has been found, however, in accordance with the present invention, that if one side of the galvanized strip is wiped shortly after it emerges from the exit rolls 8 and before the zinc coating thereon has hardened, so as to remove the greater part of the coating thereon, it then becomes possible to apply a small amount of heat to the thinly coated side of the strip so as to cause the zinc coating on that side to alloy rapidly with the base material, and that if the heat is properly controlled, the interface alloy on the opposite side of the strip will not be increased in thickness, and that the standard or heavy Zinc coating thereon will not be affected as to its adherence or ductility. The new product, therefore, is a sheet or strip which has a standard or heavy zinc coating upon one side, the characteristics of which have not been affected, and upon the other side a very thin layer of zinc alloyed with the ferrous base metal. Such a product has never before been produced.
In the practice of the invention the pretreatment of the strip and the coating are carried on as is usual in the practice of the Sendzimir patent to which reference has been made. If desired, the exit rolls may be grooved in such a way as to apply coatings of different thicknesses to opposite sides of the strip, or an air blast may he used on the meniscus on one side, as mentioned above. These expedients, however, are not necessary. The use of a scraper blade 9 is the preferred procedure, the blade being so located as to deflect the strip as shown and insure contact all across its Width. A blade properly used will be effective in removing the major portion of the zinc galvanizing metal on the side of the strip contacted by it.
The zinc coating on the opposite side of the strip does not constitute a limitation on the invention. Depending upon the usage to which the product is to be put, the heavy coating can be as heavy as that normally produced commercially, which could be as much as one ounce or heavier, per square foot. The other, or light side, the strip can have coatings as light as .1 ounce, or less, per square foot.
The heat applied to the wiped side of the strip is conveniently produced by one or more gas ribbon burners It or some other suitable heat source, such as an electrical heating means. Assuming that the strip leaves the coating pot in a vertical direction, the burners will be placed in a horizontal position extending across the strip. The exact position of the burners with respect to the exit rolls is not critical; and it has been found that the burners may vary from about one foot to ten feet from the exit rolls. The burners will be located at such a distance from the surface of the strip as to produce the proper heat at that surface. In general, the burners will lie from 2 inches to 8 inches away from the strip. The heat may vary from 500 F. to about 1400 F. at the surface of the strip. The heating should be done in such a way that, while the adjacent and thinly coated surface of the strip is heated to the desired temperature, the rate of heat dissipation from the strip as it cools in air will prevent the transmission of any great degree of heat to the opposite side of the strip. The temperature may be varied in accordance with the thickness of the zinc coating remaining on the wiped side of the strip, and the amount of heat required to cause it to alloy with the base metal.
In the practice of the invention, it may be found advisable to raise the temperature of the molten metal in the coating pot. The pot temperature may be raised as high as about 870 F. without essentially affecting the characteristics of the standard or heavy zinc coating upon the one side of the sheet.
Modifications may be made in the invention without departing from the spirit of it. The invention having been described in certain exemplary embodiments, what is claimed as new and desired to be secured by Letters Patent is:
1. A process of making a differentially coated galvanized stock which comprises forming zinc coatings of unequal thickness on opposite sides of a ferrous sheet stock, and subjecting the sheet stock upon the side hearing the coating of lesser thickness briefly to localized heat sufficient to alloy the zinc on the said last mentioned side substantially entirely with the ferrous sheet stock, while leaving substantially unaffected on the opposite side of the sheet both the layer of zinc coating metal thereon and any interface alloy existing between said layer and the base metal.
2. A process of producing a differentially coated galvanized ferrous sheet product which comprises subjecting ferrous strip to a cleaning and oxidizing operation so as to form thereon a thin uniform film of oxide, passing the strip so treated through a reducing furnace and heatiug it therein in the presence of reducing gases so as thoroughly to reduce the said oxide layer, and through a cooling hood containing reducing gases so as to introduce it into a bath of molten zinc coating metal through a flux free surface thereof, withdrawing the said st." from said bath through exit rolls, scraping one surface of said strip above one of said exit rolls so as to remove the greater part of the coating of zinc coating metal thereon, and then subjecting the same side of said strip to localized heat to cause the remaining zinc thereon to alloy with the ferrous strip surface without essentially affecting the coating of zinc coating metal or the opposite side of said strip.
3. The process claimed in claim 2 wherein said zinc coating metal contains a minor percentage of aluminum.
A process of making a differentially coated galvanized stock which comprises passing ferrous strip through a bath of molten coating metal of which the primary constituent is zinc, under conditions to cause the said molten coating metal to cling to and coat the surfaces of the said ferrous strip, and upon withdrawal of the ferrous strip from the bath of molten coating metal treating the surfaces thereof so that the resident layer of coating metal upon one side of it is substantially thicker than the coating thereof upon the other side, and after the said treatment applying localized heat to the thinner coating upon the last mentioned side of said ferrous strip so as to cause the said coating metal in the said thinner coating to alloy substantially entirely with the ferrous strip, while leaving subtsantially unaffected upon the opposite side of said strip both the thicker layer of coating metal thereon and any interface alloy existing between said layer and the base metal.
5. The process claimed in claim 4 wherein the coating metal is zinc containing a minor percentage of aluminum.
6. The process claimed in claim 5 wherein the layer of coating metal upon the first mentioned side of said strip is at least about one ounce per square foot, and wherein the layer of coating metal as formed upon the second mentioned side of said strip is not greater than about 0.1 ounce per square foot of the strip surface.
References Cited in the file of this patent UNITED STATES PATENTS

Claims (1)

  1. 2. A PROCESS OF PRODUCING A DIFFERENTIALLY COATED GALVANIZED FERROUS SHEET PRODUCT WHICH COMPRISES SUBJECTING FERROUS STRIP TO A CLEANING AND OXIDIZING OPERATION SO AS TO FORM THEREON A THIN UNIFORM FILM OF OXIDE, PASSING THE STRIP SO TREATED THROUGH A REDUCING FURNACE AND HEATING IT THEREIN IN THE PRESENCE OF REDUCING GASES SO AS THOROUGHLY TO REDUCE THE SAID OXIDE LAYER, AND THROUGH A COOLING HOOD CONTAINING REDUCING GASES SO AS TO INTRODUCE IT INTO A BATH OF MOLTEN ZINC COATING METAL THROUGH A FLUX FREE SURFACE THEREOF, WITHDRAWING THE SAID STRIP FROM SAID BATH THROUGH EXIT ROLLS. SCRAPING ONE SURFACE OF SAID STRIP ABOVE ONE OF SAID EXIT ROLLS SO AS TO REMOVE THE GREATER PART OF THE COATING OF ZINC COATING METAL THEREON, AND THEN SUBJECTING THE SAME SIDE OF SAID STRIP TO LOCALIZED HEAT TO CAUSE THE REMAINING ZINC THEREON TO ALLOY WITH THE FERROUS STRIP SURFACE WITHOUT ESSENTIALLY AFFECTING THE COATING OF ZINC COATING METAL OR THE OPPOSITE SIDE OF SAID STRIP.
US862082A 1959-12-28 1959-12-28 Differentially coated galvanized strip Expired - Lifetime US3112213A (en)

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GB42739/60A GB904485A (en) 1959-12-28 1960-12-12 Differentially coated galvanized sheet or strip
US256530A US3177053A (en) 1959-12-28 1963-02-06 Differentially coated galvanized strip

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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3260577A (en) * 1961-12-20 1966-07-12 Nat Steel Corp Coated product and its manufacture
US3322558A (en) * 1963-06-14 1967-05-30 Selas Corp Of America Galvanizing
US3977842A (en) * 1968-08-27 1976-08-31 National Steel Corporation Product and process
US4171394A (en) * 1977-11-30 1979-10-16 Inland Steel Company Process of hot-dip galvanizing and alloying
US4171392A (en) * 1978-11-08 1979-10-16 Inland Steel Company Process of producing one-side alloyed galvanized steel strip
US4291074A (en) * 1978-11-09 1981-09-22 Laminoirs De Strasbourg Process for producing a sheet or strip which is lightly galvanized on one or both sides and products obtained by said process
US20090142538A1 (en) * 2007-06-08 2009-06-04 Gm Global Technology Operations, Inc. Corrosion resistant precoated laminated steel
US8540842B2 (en) 2008-08-18 2013-09-24 Productive Research Llc Formable light weight composites
US8796580B2 (en) 2009-12-28 2014-08-05 Productive Research Processes for welding composite materials and articles therefrom
US9005768B2 (en) 2011-02-21 2015-04-14 Productive Research Composite materials including regions differing in properties and methods
US9115264B2 (en) 2010-02-15 2015-08-25 Productive Research Llc Delamination resistant, weldable and formable light weight composites
US9233526B2 (en) 2012-08-03 2016-01-12 Productive Research Llc Composites having improved interlayer adhesion and methods thereof
US11338552B2 (en) 2019-02-15 2022-05-24 Productive Research Llc Composite materials, vehicle applications and methods thereof

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US3260577A (en) * 1961-12-20 1966-07-12 Nat Steel Corp Coated product and its manufacture
US3322558A (en) * 1963-06-14 1967-05-30 Selas Corp Of America Galvanizing
US3977842A (en) * 1968-08-27 1976-08-31 National Steel Corporation Product and process
US4171394A (en) * 1977-11-30 1979-10-16 Inland Steel Company Process of hot-dip galvanizing and alloying
US4171392A (en) * 1978-11-08 1979-10-16 Inland Steel Company Process of producing one-side alloyed galvanized steel strip
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JPS55500872A (en) * 1978-11-08 1980-10-30
US4291074A (en) * 1978-11-09 1981-09-22 Laminoirs De Strasbourg Process for producing a sheet or strip which is lightly galvanized on one or both sides and products obtained by said process
US20090142538A1 (en) * 2007-06-08 2009-06-04 Gm Global Technology Operations, Inc. Corrosion resistant precoated laminated steel
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US11084253B2 (en) 2010-02-15 2021-08-10 Productive Research Llc Light weight composite material systems, polymeric materials, and methods
US11331880B2 (en) 2010-02-15 2022-05-17 Productive Research Llc Delamination resistant, weldable and formable light weight composites
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